Zettelstore

##
## This file is part of zettelstore.
##
## Zettelstore is licensed under the latest version of the EUPL (European Union
## Public License). Please see file LICENSE.txt for your rights and obligations
## under this license.

.PHONY:  check build release clean

check:
	go run tools/build.go check




version:
	@echo $(shell go run tools/build.go version)

build:
	go run tools/build.go build

release:
	go run tools/build.go release

clean:
	go run tools/build.go clean

##
## This file is part of zettelstore.
##
## Zettelstore is licensed under the latest version of the EUPL (European Union
## Public License). Please see file LICENSE.txt for your rights and obligations
## under this license.

.PHONY:  check api build release clean

check:
	go run tools/build.go check

api:
	go run tools/build.go testapi

version:
	@echo $(shell go run tools/build.go version)

build:
	go run tools/build.go build

release:
	go run tools/build.go release

clean:
	go run tools/build.go clean

0.0.13

0.0.14

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package api contains common definition used for client and server.
package api

// AuthJSON contains the result of an authentication call.
type AuthJSON struct {
	Token   string `json:"token"`
	Type    string `json:"token_type"`
	Expires int    `json:"expires_in"`
}

// ZidJSON contains the identifier data of a zettel.
type ZidJSON struct {
	ID  string `json:"id"`
	URL string `json:"url"`
}

// ZidMetaJSON contains the identifier and the metadata of a zettel.
type ZidMetaJSON struct {
	ID   string            `json:"id"`
	URL  string            `json:"url"`
	Meta map[string]string `json:"meta"`
}

// ZidMetaRelatedList contains identifier/metadata of a zettel and the same for related zettel
type ZidMetaRelatedList struct {
	ID   string            `json:"id"`
	URL  string            `json:"url"`
	Meta map[string]string `json:"meta"`
	List []ZidMetaJSON     `json:"list"`
}

// ZettelLinksJSON store all links / connections from one zettel to other.
type ZettelLinksJSON struct {
	ID    string `json:"id"`
	URL   string `json:"url"`
	Links struct {
		Incoming []ZidJSON `json:"incoming,omitempty"`
		Outgoing []ZidJSON `json:"outgoing,omitempty"`
		Local    []string  `json:"local,omitempty"`
		External []string  `json:"external,omitempty"`
		Meta     []string  `json:"meta,omitempty"`
	} `json:"links"`
	Images struct {
		Outgoing []ZidJSON `json:"outgoing,omitempty"`
		Local    []string  `json:"local,omitempty"`
		External []string  `json:"external,omitempty"`
	} `json:"images,omitempty"`
	Cites []string `json:"cites,omitempty"`
}

// ZettelDataJSON contains all data for a zettel.
type ZettelDataJSON struct {
	Meta     map[string]string `json:"meta"`
	Encoding string            `json:"encoding"`
	Content  string            `json:"content"`
}

// ZettelJSON contains all data for a zettel, the identifier, the metadata, and the content.
type ZettelJSON struct {
	ID       string            `json:"id"`
	URL      string            `json:"url"`
	Meta     map[string]string `json:"meta"`
	Encoding string            `json:"encoding"`
	Content  string            `json:"content"`
}

// ZettelListJSON contains data for a zettel list.
type ZettelListJSON struct {
	List []ZettelJSON `json:"list"`
}

// TagListJSON specifies the list/map of tags
type TagListJSON struct {
	Tags map[string][]string `json:"tags"`
}

// RoleListJSON specifies the list of roles.
type RoleListJSON struct {
	Roles []string `json:"role-list"`
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package api contains common definition used for client and server.
package api

import (
	"fmt"
)

// Additional HTTP constants used.
const (
	MethodMove = "MOVE" // HTTP method for renaming a zettel

	HeaderAccept      = "Accept"
	HeaderContentType = "Content-Type"
	HeaderDestination = "Destination"
	HeaderLocation    = "Location"
)

// Values for HTTP query parameter.
const (
	QueryKeyDepth  = "depth"
	QueryKeyDir    = "dir"
	QueryKeyFormat = "_format"
	QueryKeyLimit  = "limit"
	QueryKeyPart   = "_part"
)

// Supported dir values.
const (
	DirBackward = "backward"
	DirForward  = "forward"
)

// Supported format values.
const (
	FormatDJSON  = "djson"
	FormatHTML   = "html"
	FormatJSON   = "json"
	FormatNative = "native"
	FormatRaw    = "raw"
	FormatText   = "text"
	FormatZMK    = "zmk"
)

var formatEncoder = map[string]EncodingEnum{
	FormatDJSON:  EncoderDJSON,
	FormatHTML:   EncoderHTML,
	FormatJSON:   EncoderJSON,
	FormatNative: EncoderNative,
	FormatRaw:    EncoderRaw,
	FormatText:   EncoderText,
	FormatZMK:    EncoderZmk,
}
var encoderFormat = map[EncodingEnum]string{}

func init() {
	for k, v := range formatEncoder {
		encoderFormat[v] = k
	}
}

// Encoder returns the internal encoder code for the given format string.
func Encoder(format string) EncodingEnum {
	if e, ok := formatEncoder[format]; ok {
		return e
	}
	return EncoderUnknown
}

// EncodingEnum lists all valid encoder keys.
type EncodingEnum uint8

// Values for EncoderEnum
const (
	EncoderUnknown EncodingEnum = iota
	EncoderDJSON
	EncoderHTML
	EncoderJSON
	EncoderNative
	EncoderRaw
	EncoderText
	EncoderZmk
)

// String representation of an encoder key.
func (e EncodingEnum) String() string {
	if f, ok := encoderFormat[e]; ok {
		return f
	}
	return fmt.Sprintf("*Unknown*(%d)", e)
}

// Supported part values.
const (
	PartID      = "id"
	PartMeta    = "meta"
	PartContent = "content"
	PartZettel  = "zettel"
)

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package api contains common definition used for client and server.
package api

import (
	"net/url"
	"strings"

	"zettelstore.de/z/domain/id"
)

type urlQuery struct{ key, val string }

// URLBuilder should be used to create zettelstore URLs.
type URLBuilder struct {
	prefix   string
	key      byte
	path     []string
	query    []urlQuery
	fragment string
}

// NewURLBuilder creates a new URL builder with the given prefix and key.
func NewURLBuilder(prefix string, key byte) *URLBuilder {
	return &URLBuilder{prefix: prefix, key: key}
}

// Clone an URLBuilder
func (ub *URLBuilder) Clone() *URLBuilder {
	cpy := new(URLBuilder)
	cpy.key = ub.key
	if len(ub.path) > 0 {
		cpy.path = make([]string, 0, len(ub.path))
		cpy.path = append(cpy.path, ub.path...)
	}
	if len(ub.query) > 0 {
		cpy.query = make([]urlQuery, 0, len(ub.query))
		cpy.query = append(cpy.query, ub.query...)
	}
	cpy.fragment = ub.fragment
	return cpy
}

// SetZid sets the zettel identifier.
func (ub *URLBuilder) SetZid(zid id.Zid) *URLBuilder {
	if len(ub.path) > 0 {
		panic("Cannot add Zid")
	}
	ub.path = append(ub.path, zid.String())
	return ub
}

// AppendPath adds a new path element
func (ub *URLBuilder) AppendPath(p string) *URLBuilder {
	ub.path = append(ub.path, p)
	return ub
}

// AppendQuery adds a new query parameter
func (ub *URLBuilder) AppendQuery(key, value string) *URLBuilder {
	ub.query = append(ub.query, urlQuery{key, value})
	return ub
}

// ClearQuery removes all query parameters.
func (ub *URLBuilder) ClearQuery() *URLBuilder {
	ub.query = nil
	ub.fragment = ""
	return ub
}

// SetFragment stores the fragment
func (ub *URLBuilder) SetFragment(s string) *URLBuilder {
	ub.fragment = s
	return ub
}

// String produces a string value.
func (ub *URLBuilder) String() string {
	var sb strings.Builder

	sb.WriteString(ub.prefix)
	if ub.key != '/' {
		sb.WriteByte(ub.key)
	}
	for _, p := range ub.path {
		sb.WriteByte('/')
		sb.WriteString(url.PathEscape(p))
	}
	if len(ub.fragment) > 0 {
		sb.WriteByte('#')
		sb.WriteString(ub.fragment)
	}
	for i, q := range ub.query {
		if i == 0 {
			sb.WriteByte('?')
		} else {
			sb.WriteByte('&')
		}
		sb.WriteString(q.key)
		sb.WriteByte('=')
		sb.WriteString(url.QueryEscape(q.val))
	}
	return sb.String()
}

	Zid     id.Zid         // Zettel identification.
	InhMeta *meta.Meta     // Metadata of the zettel, with inherited values.
	Ast     BlockSlice     // Zettel abstract syntax tree is a sequence of block nodes.
}

// Node is the interface, all nodes must implement.
type Node interface {
	Accept(v Visitor)
}

// BlockNode is the interface that all block nodes must implement.
type BlockNode interface {
	Node
	blockNode()
}

	Zid     id.Zid         // Zettel identification.
	InhMeta *meta.Meta     // Metadata of the zettel, with inherited values.
	Ast     BlockSlice     // Zettel abstract syntax tree is a sequence of block nodes.
}

// Node is the interface, all nodes must implement.
type Node interface {
	WalkChildren(v Visitor)
}

// BlockNode is the interface that all block nodes must implement.
type BlockNode interface {
	Node
	blockNode()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------
................................................................................
import (
	"testing"

	"zettelstore.de/z/ast"
)

func TestHasDefault(t *testing.T) {

	attr := &ast.Attributes{}
	if attr.HasDefault() {
		t.Error("Should not have default attr")
	}
	attr = &ast.Attributes{Attrs: map[string]string{"-": "value"}}
	if !attr.HasDefault() {
		t.Error("Should have default attr")
	}
}

func TestAttrClone(t *testing.T) {

	orig := &ast.Attributes{}
	clone := orig.Clone()
	if len(clone.Attrs) > 0 {
		t.Error("Attrs must be empty")
	}

	orig = &ast.Attributes{Attrs: map[string]string{"": "0", "-": "1", "a": "b"}}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------
................................................................................
import (
	"testing"

	"zettelstore.de/z/ast"
)

func TestHasDefault(t *testing.T) {
	t.Parallel()
	attr := &ast.Attributes{}
	if attr.HasDefault() {
		t.Error("Should not have default attr")
	}
	attr = &ast.Attributes{Attrs: map[string]string{"-": "value"}}
	if !attr.HasDefault() {
		t.Error("Should have default attr")
	}
}

func TestAttrClone(t *testing.T) {
	t.Parallel()
	orig := &ast.Attributes{}
	clone := orig.Clone()
	if len(clone.Attrs) > 0 {
		t.Error("Attrs must be empty")
	}

	orig = &ast.Attributes{Attrs: map[string]string{"": "0", "-": "1", "a": "b"}}

// ParaNode contains just a sequence of inline elements.
// Another name is "paragraph".
type ParaNode struct {
	Inlines InlineSlice
}

func (pn *ParaNode) blockNode()       {}
func (pn *ParaNode) itemNode()        {}
func (pn *ParaNode) descriptionNode() {}

// Accept a visitor and visit the node.
func (pn *ParaNode) Accept(v Visitor) { v.VisitPara(pn) }



//--------------------------------------------------------------------------

// VerbatimNode contains lines of uninterpreted text
type VerbatimNode struct {
	Code  VerbatimCode
	Attrs *Attributes
	Lines []string
}

// VerbatimCode specifies the format that is applied to code inline nodes.
type VerbatimCode int

// Constants for VerbatimCode
const (
	_               VerbatimCode = iota
	VerbatimProg                 // Program code.
	VerbatimComment              // Block comment
	VerbatimHTML                 // Block HTML, e.g. for Markdown
)

func (vn *VerbatimNode) blockNode() {}
func (vn *VerbatimNode) itemNode()  {}

// Accept a visitor an visit the node.
func (vn *VerbatimNode) Accept(v Visitor) { v.VisitVerbatim(vn) }

//--------------------------------------------------------------------------

// RegionNode encapsulates a region of block nodes.
type RegionNode struct {
	Code    RegionCode
	Attrs   *Attributes
	Blocks  BlockSlice
	Inlines InlineSlice // Additional text at the end of the region
}

// RegionCode specifies the actual region type.
type RegionCode int

// Values for RegionCode
const (
	_           RegionCode = iota
	RegionSpan             // Just a span of blocks
	RegionQuote            // A longer quotation
	RegionVerse            // Line breaks matter
)

func (rn *RegionNode) blockNode() {}
func (rn *RegionNode) itemNode()  {}

// Accept a visitor and visit the node.
func (rn *RegionNode) Accept(v Visitor) { v.VisitRegion(rn) }




//--------------------------------------------------------------------------

// HeadingNode stores the heading text and level.
type HeadingNode struct {
	Level   int
	Inlines InlineSlice // Heading text, possibly formatted
	Slug    string      // Heading text, suitable to be used as an URL fragment
	Attrs   *Attributes
}

func (hn *HeadingNode) blockNode() {}
func (hn *HeadingNode) itemNode()  {}

// Accept a visitor and visit the node.
func (hn *HeadingNode) Accept(v Visitor) { v.VisitHeading(hn) }



//--------------------------------------------------------------------------

// HRuleNode specifies a horizontal rule.
type HRuleNode struct {
	Attrs *Attributes
}

func (hn *HRuleNode) blockNode() {}
func (hn *HRuleNode) itemNode()  {}

// Accept a visitor and visit the node.
func (hn *HRuleNode) Accept(v Visitor) { v.VisitHRule(hn) }

//--------------------------------------------------------------------------

// NestedListNode specifies a nestable list, either ordered or unordered.
type NestedListNode struct {
	Code  NestedListCode
	Items []ItemSlice
	Attrs *Attributes
}

// NestedListCode specifies the actual list type.
type NestedListCode int

// Values for ListCode
const (
	_                   NestedListCode = iota
	NestedListOrdered                  // Ordered list.
	NestedListUnordered                // Unordered list.
	NestedListQuote                    // Quote list.
)

func (ln *NestedListNode) blockNode() {}
func (ln *NestedListNode) itemNode()  {}

// Accept a visitor and visit the node.
func (ln *NestedListNode) Accept(v Visitor) { v.VisitNestedList(ln) }





//--------------------------------------------------------------------------

// DescriptionListNode specifies a description list.
type DescriptionListNode struct {
	Descriptions []Description
}
................................................................................
type Description struct {
	Term         InlineSlice
	Descriptions []DescriptionSlice
}

func (dn *DescriptionListNode) blockNode() {}

// Accept a visitor and visit the node.
func (dn *DescriptionListNode) Accept(v Visitor) { v.VisitDescriptionList(dn) }








//--------------------------------------------------------------------------

// TableNode specifies a full table
type TableNode struct {
	Header TableRow    // The header row
	Align  []Alignment // Default column alignment
................................................................................
	_            Alignment = iota
	AlignDefault           // Default alignment, inherited
	AlignLeft              // Left alignment
	AlignCenter            // Center the content
	AlignRight             // Right alignment
)

func (tn *TableNode) blockNode() {}

// Accept a visitor and visit the node.
func (tn *TableNode) Accept(v Visitor) { v.VisitTable(tn) }










//--------------------------------------------------------------------------

// BLOBNode contains just binary data that must be interpreted according to
// a syntax.
type BLOBNode struct {
	Title  string
	Syntax string
	Blob   []byte
}

func (bn *BLOBNode) blockNode() {}

// Accept a visitor and visit the node.
func (bn *BLOBNode) Accept(v Visitor) { v.VisitBLOB(bn) }

// ParaNode contains just a sequence of inline elements.
// Another name is "paragraph".
type ParaNode struct {
	Inlines InlineSlice
}

func (pn *ParaNode) blockNode()       { /* Just a marker */ }
func (pn *ParaNode) itemNode()        { /* Just a marker */ }
func (pn *ParaNode) descriptionNode() { /* Just a marker */ }

// WalkChildren walks down the inline elements.
func (pn *ParaNode) WalkChildren(v Visitor) {
	WalkInlineSlice(v, pn.Inlines)
}

//--------------------------------------------------------------------------

// VerbatimNode contains lines of uninterpreted text
type VerbatimNode struct {
	Kind  VerbatimKind
	Attrs *Attributes
	Lines []string
}

// VerbatimKind specifies the format that is applied to code inline nodes.
type VerbatimKind uint8

// Constants for VerbatimCode
const (
	_               VerbatimKind = iota
	VerbatimProg                 // Program code.
	VerbatimComment              // Block comment
	VerbatimHTML                 // Block HTML, e.g. for Markdown
)

func (vn *VerbatimNode) blockNode() { /* Just a marker */ }
func (vn *VerbatimNode) itemNode()  { /* Just a marker */ }

// WalkChildren does nothing.
func (vn *VerbatimNode) WalkChildren(v Visitor) { /* No children*/ }

//--------------------------------------------------------------------------

// RegionNode encapsulates a region of block nodes.
type RegionNode struct {
	Kind    RegionKind
	Attrs   *Attributes
	Blocks  BlockSlice
	Inlines InlineSlice // Additional text at the end of the region
}

// RegionKind specifies the actual region type.
type RegionKind uint8

// Values for RegionCode
const (
	_           RegionKind = iota
	RegionSpan             // Just a span of blocks
	RegionQuote            // A longer quotation
	RegionVerse            // Line breaks matter
)

func (rn *RegionNode) blockNode() { /* Just a marker */ }
func (rn *RegionNode) itemNode()  { /* Just a marker */ }

// WalkChildren walks down the blocks and the text.
func (rn *RegionNode) WalkChildren(v Visitor) {
	WalkBlockSlice(v, rn.Blocks)
	WalkInlineSlice(v, rn.Inlines)
}

//--------------------------------------------------------------------------

// HeadingNode stores the heading text and level.
type HeadingNode struct {
	Level   int
	Inlines InlineSlice // Heading text, possibly formatted
	Slug    string      // Heading text, suitable to be used as an URL fragment
	Attrs   *Attributes
}

func (hn *HeadingNode) blockNode() { /* Just a marker */ }
func (hn *HeadingNode) itemNode()  { /* Just a marker */ }

// WalkChildren walks the heading text.
func (hn *HeadingNode) WalkChildren(v Visitor) {
	WalkInlineSlice(v, hn.Inlines)
}

//--------------------------------------------------------------------------

// HRuleNode specifies a horizontal rule.
type HRuleNode struct {
	Attrs *Attributes
}

func (hn *HRuleNode) blockNode() { /* Just a marker */ }
func (hn *HRuleNode) itemNode()  { /* Just a marker */ }

// WalkChildren does nothing.
func (hn *HRuleNode) WalkChildren(v Visitor) { /* No children*/ }

//--------------------------------------------------------------------------

// NestedListNode specifies a nestable list, either ordered or unordered.
type NestedListNode struct {
	Kind  NestedListKind
	Items []ItemSlice
	Attrs *Attributes
}

// NestedListKind specifies the actual list type.
type NestedListKind uint8

// Values for ListCode
const (
	_                   NestedListKind = iota
	NestedListOrdered                  // Ordered list.
	NestedListUnordered                // Unordered list.
	NestedListQuote                    // Quote list.
)

func (ln *NestedListNode) blockNode() { /* Just a marker */ }
func (ln *NestedListNode) itemNode()  { /* Just a marker */ }

// WalkChildren walks down the items.
func (ln *NestedListNode) WalkChildren(v Visitor) {
	for _, item := range ln.Items {
		WalkItemSlice(v, item)
	}
}

//--------------------------------------------------------------------------

// DescriptionListNode specifies a description list.
type DescriptionListNode struct {
	Descriptions []Description
}
................................................................................
type Description struct {
	Term         InlineSlice
	Descriptions []DescriptionSlice
}

func (dn *DescriptionListNode) blockNode() {}

// WalkChildren walks down to the descriptions.
func (dn *DescriptionListNode) WalkChildren(v Visitor) {
	for _, desc := range dn.Descriptions {
		WalkInlineSlice(v, desc.Term)
		for _, dns := range desc.Descriptions {
			WalkDescriptionSlice(v, dns)
		}
	}
}

//--------------------------------------------------------------------------

// TableNode specifies a full table
type TableNode struct {
	Header TableRow    // The header row
	Align  []Alignment // Default column alignment
................................................................................
	_            Alignment = iota
	AlignDefault           // Default alignment, inherited
	AlignLeft              // Left alignment
	AlignCenter            // Center the content
	AlignRight             // Right alignment
)

func (tn *TableNode) blockNode() { /* Just a marker */ }

// WalkChildren walks down to the cells.
func (tn *TableNode) WalkChildren(v Visitor) {
	for _, cell := range tn.Header {
		WalkInlineSlice(v, cell.Inlines)
	}
	for _, row := range tn.Rows {
		for _, cell := range row {
			WalkInlineSlice(v, cell.Inlines)
		}
	}
}

//--------------------------------------------------------------------------

// BLOBNode contains just binary data that must be interpreted according to
// a syntax.
type BLOBNode struct {
	Title  string
	Syntax string
	Blob   []byte
}

func (bn *BLOBNode) blockNode() { /* Just a marker */ }

// WalkChildren does nothing.
func (bn *BLOBNode) WalkChildren(v Visitor) { /* No children*/ }

// Definitions of inline nodes.

// TextNode just contains some text.
type TextNode struct {
	Text string // The text itself.
}

func (tn *TextNode) inlineNode() {}

// Accept a visitor and visit the node.
func (tn *TextNode) Accept(v Visitor) { v.VisitText(tn) }

// --------------------------------------------------------------------------

// TagNode contains a tag.
type TagNode struct {
	Tag string // The text itself.
}

func (tn *TagNode) inlineNode() {}

// Accept a visitor and visit the node.
func (tn *TagNode) Accept(v Visitor) { v.VisitTag(tn) }

// --------------------------------------------------------------------------

// SpaceNode tracks inter-word space characters.
type SpaceNode struct {
	Lexeme string
}

func (sn *SpaceNode) inlineNode() {}

// Accept a visitor and visit the node.
func (sn *SpaceNode) Accept(v Visitor) { v.VisitSpace(sn) }

// --------------------------------------------------------------------------

// BreakNode signals a new line that must / should be interpreted as a new line break.
type BreakNode struct {
	Hard bool // Hard line break?
}

func (bn *BreakNode) inlineNode() {}

// Accept a visitor and visit the node.
func (bn *BreakNode) Accept(v Visitor) { v.VisitBreak(bn) }

// --------------------------------------------------------------------------

// LinkNode contains the specified link.
type LinkNode struct {
	Ref     *Reference
	Inlines InlineSlice // The text associated with the link.
	OnlyRef bool        // True if no text was specified.
	Attrs   *Attributes // Optional attributes
}

func (ln *LinkNode) inlineNode() {}

// Accept a visitor and visit the node.
func (ln *LinkNode) Accept(v Visitor) { v.VisitLink(ln) }



// --------------------------------------------------------------------------

// ImageNode contains the specified image reference.
type ImageNode struct {
	Ref     *Reference  // Reference to image
	Blob    []byte      // BLOB data of the image, as an alternative to Ref.
	Syntax  string      // Syntax of Blob
	Inlines InlineSlice // The text associated with the image.
	Attrs   *Attributes // Optional attributes
}

func (in *ImageNode) inlineNode() {}

// Accept a visitor and visit the node.
func (in *ImageNode) Accept(v Visitor) { v.VisitImage(in) }



// --------------------------------------------------------------------------

// CiteNode contains the specified citation.
type CiteNode struct {
	Key     string      // The citation key
	Inlines InlineSlice // The text associated with the citation.
	Attrs   *Attributes // Optional attributes
}

func (cn *CiteNode) inlineNode() {}

// Accept a visitor and visit the node.
func (cn *CiteNode) Accept(v Visitor) { v.VisitCite(cn) }



// --------------------------------------------------------------------------

// MarkNode contains the specified merked position.
// It is a BlockNode too, because although it is typically parsed during inline
// mode, it is moved into block mode afterwards.
type MarkNode struct {
	Text string
}

func (mn *MarkNode) inlineNode() {}

// Accept a visitor and visit the node.
func (mn *MarkNode) Accept(v Visitor) { v.VisitMark(mn) }

// --------------------------------------------------------------------------

// FootnoteNode contains the specified footnote.
type FootnoteNode struct {
	Inlines InlineSlice // The footnote text.
	Attrs   *Attributes // Optional attributes
}

func (fn *FootnoteNode) inlineNode() {}

// Accept a visitor and visit the node.
func (fn *FootnoteNode) Accept(v Visitor) { v.VisitFootnote(fn) }



// --------------------------------------------------------------------------

// FormatNode specifies some inline formatting.
type FormatNode struct {
	Code    FormatCode
	Attrs   *Attributes // Optional attributes.
	Inlines InlineSlice
}

// FormatCode specifies the format that is applied to the inline nodes.
type FormatCode int

// Constants for FormatCode
const (
	_               FormatCode = iota
	FormatItalic               // Italic text.
	FormatEmph                 // Semantically emphasized text.
	FormatBold                 // Bold text.
	FormatStrong               // Semantically strongly emphasized text.
	FormatUnder                // Underlined text.
	FormatInsert               // Inserted text.
	FormatStrike               // Text that is no longer relevant or no longer accurate.
................................................................................
	FormatQuote                // Quoted text.
	FormatQuotation            // Quotation text.
	FormatSmall                // Smaller text.
	FormatSpan                 // Generic inline container.
	FormatMonospace            // Monospaced text.
)

func (fn *FormatNode) inlineNode() {}

// Accept a visitor and visit the node.
func (fn *FormatNode) Accept(v Visitor) { v.VisitFormat(fn) }



// --------------------------------------------------------------------------

// LiteralNode specifies some uninterpreted text.
type LiteralNode struct {
	Code  LiteralCode
	Attrs *Attributes // Optional attributes.
	Text  string
}

// LiteralCode specifies the format that is applied to code inline nodes.
type LiteralCode int

// Constants for LiteralCode
const (
	_              LiteralCode = iota
	LiteralProg                // Inline program code.
	LiteralKeyb                // Keyboard strokes.
	LiteralOutput              // Sample output.
	LiteralComment             // Inline comment
	LiteralHTML                // Inline HTML, e.g. for Markdown
)

func (rn *LiteralNode) inlineNode() {}

// Accept a visitor and visit the node.
func (rn *LiteralNode) Accept(v Visitor) { v.VisitLiteral(rn) }

// Definitions of inline nodes.

// TextNode just contains some text.
type TextNode struct {
	Text string // The text itself.
}

func (tn *TextNode) inlineNode() { /* Just a marker */ }

// WalkChildren does nothing.
func (tn *TextNode) WalkChildren(v Visitor) { /* No children*/ }

// --------------------------------------------------------------------------

// TagNode contains a tag.
type TagNode struct {
	Tag string // The text itself.
}

func (tn *TagNode) inlineNode() { /* Just a marker */ }

// WalkChildren does nothing.
func (tn *TagNode) WalkChildren(v Visitor) { /* No children*/ }

// --------------------------------------------------------------------------

// SpaceNode tracks inter-word space characters.
type SpaceNode struct {
	Lexeme string
}

func (sn *SpaceNode) inlineNode() { /* Just a marker */ }

// WalkChildren does nothing.
func (sn *SpaceNode) WalkChildren(v Visitor) { /* No children*/ }

// --------------------------------------------------------------------------

// BreakNode signals a new line that must / should be interpreted as a new line break.
type BreakNode struct {
	Hard bool // Hard line break?
}

func (bn *BreakNode) inlineNode() { /* Just a marker */ }

// WalkChildren does nothing.
func (bn *BreakNode) WalkChildren(v Visitor) { /* No children*/ }

// --------------------------------------------------------------------------

// LinkNode contains the specified link.
type LinkNode struct {
	Ref     *Reference
	Inlines InlineSlice // The text associated with the link.
	OnlyRef bool        // True if no text was specified.
	Attrs   *Attributes // Optional attributes
}

func (ln *LinkNode) inlineNode() { /* Just a marker */ }

// WalkChildren walks to the link text.
func (ln *LinkNode) WalkChildren(v Visitor) {
	WalkInlineSlice(v, ln.Inlines)
}

// --------------------------------------------------------------------------

// ImageNode contains the specified image reference.
type ImageNode struct {
	Ref     *Reference  // Reference to image
	Blob    []byte      // BLOB data of the image, as an alternative to Ref.
	Syntax  string      // Syntax of Blob
	Inlines InlineSlice // The text associated with the image.
	Attrs   *Attributes // Optional attributes
}

func (in *ImageNode) inlineNode() { /* Just a marker */ }

// WalkChildren walks to the image text.
func (in *ImageNode) WalkChildren(v Visitor) {
	WalkInlineSlice(v, in.Inlines)
}

// --------------------------------------------------------------------------

// CiteNode contains the specified citation.
type CiteNode struct {
	Key     string      // The citation key
	Inlines InlineSlice // The text associated with the citation.
	Attrs   *Attributes // Optional attributes
}

func (cn *CiteNode) inlineNode() { /* Just a marker */ }

// WalkChildren walks to the cite text.
func (cn *CiteNode) WalkChildren(v Visitor) {
	WalkInlineSlice(v, cn.Inlines)
}

// --------------------------------------------------------------------------

// MarkNode contains the specified merked position.
// It is a BlockNode too, because although it is typically parsed during inline
// mode, it is moved into block mode afterwards.
type MarkNode struct {
	Text string
}

func (mn *MarkNode) inlineNode() { /* Just a marker */ }

// WalkChildren does nothing.
func (mn *MarkNode) WalkChildren(v Visitor) { /* No children*/ }

// --------------------------------------------------------------------------

// FootnoteNode contains the specified footnote.
type FootnoteNode struct {
	Inlines InlineSlice // The footnote text.
	Attrs   *Attributes // Optional attributes
}

func (fn *FootnoteNode) inlineNode() { /* Just a marker */ }

// WalkChildren walks to the footnote text.
func (fn *FootnoteNode) WalkChildren(v Visitor) {
	WalkInlineSlice(v, fn.Inlines)
}

// --------------------------------------------------------------------------

// FormatNode specifies some inline formatting.
type FormatNode struct {
	Kind    FormatKind
	Attrs   *Attributes // Optional attributes.
	Inlines InlineSlice
}

// FormatKind specifies the format that is applied to the inline nodes.
type FormatKind uint8

// Constants for FormatCode
const (
	_               FormatKind = iota
	FormatItalic               // Italic text.
	FormatEmph                 // Semantically emphasized text.
	FormatBold                 // Bold text.
	FormatStrong               // Semantically strongly emphasized text.
	FormatUnder                // Underlined text.
	FormatInsert               // Inserted text.
	FormatStrike               // Text that is no longer relevant or no longer accurate.
................................................................................
	FormatQuote                // Quoted text.
	FormatQuotation            // Quotation text.
	FormatSmall                // Smaller text.
	FormatSpan                 // Generic inline container.
	FormatMonospace            // Monospaced text.
)

func (fn *FormatNode) inlineNode() { /* Just a marker */ }

// WalkChildren walks to the formatted text.
func (fn *FormatNode) WalkChildren(v Visitor) {
	WalkInlineSlice(v, fn.Inlines)
}

// --------------------------------------------------------------------------

// LiteralNode specifies some uninterpreted text.
type LiteralNode struct {
	Kind  LiteralKind
	Attrs *Attributes // Optional attributes.
	Text  string
}

// LiteralKind specifies the format that is applied to code inline nodes.
type LiteralKind uint8

// Constants for LiteralCode
const (
	_              LiteralKind = iota
	LiteralProg                // Inline program code.
	LiteralKeyb                // Keyboard strokes.
	LiteralOutput              // Sample output.
	LiteralComment             // Inline comment
	LiteralHTML                // Inline HTML, e.g. for Markdown
)

func (ln *LiteralNode) inlineNode() { /* Just a marker */ }

// WalkChildren does nothing.
func (ln *LiteralNode) WalkChildren(v Visitor) { /* No children*/ }

import (
	"testing"

	"zettelstore.de/z/ast"
)

func TestParseReference(t *testing.T) {

	testcases := []struct {
		link string
		err  bool
		exp  string
	}{
		{"", true, ""},
		{"123", false, "123"},
................................................................................
		if got.IsValid() && got.String() != tc.exp {
			t.Errorf("TC=%d, Reference of %q is %q, but got %q", i, tc.link, tc.exp, got)
		}
	}
}

func TestReferenceIsZettelMaterial(t *testing.T) {

	testcases := []struct {
		link       string
		isZettel   bool
		isExternal bool
		isLocal    bool
	}{
		{"", false, false, false},

import (
	"testing"

	"zettelstore.de/z/ast"
)

func TestParseReference(t *testing.T) {
	t.Parallel()
	testcases := []struct {
		link string
		err  bool
		exp  string
	}{
		{"", true, ""},
		{"123", false, "123"},
................................................................................
		if got.IsValid() && got.String() != tc.exp {
			t.Errorf("TC=%d, Reference of %q is %q, but got %q", i, tc.link, tc.exp, got)
		}
	}
}

func TestReferenceIsZettelMaterial(t *testing.T) {
	t.Parallel()
	testcases := []struct {
		link       string
		isZettel   bool
		isExternal bool
		isLocal    bool
	}{
		{"", false, false, false},

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package ast provides the abstract syntax tree.
package ast

// A traverser is a Visitor that just traverses the AST and delegates node
// spacific actions to a Visitor. This Visitor should not traverse the AST.

// TopDownTraverser visits first the node and then the children nodes.
type TopDownTraverser struct {
	v Visitor
}

// NewTopDownTraverser creates a new traverser.
func NewTopDownTraverser(visitor Visitor) TopDownTraverser {
	return TopDownTraverser{visitor}
}

// VisitVerbatim has nothing to traverse.
func (t TopDownTraverser) VisitVerbatim(vn *VerbatimNode) { t.v.VisitVerbatim(vn) }

// VisitRegion traverses the content and the additional text.
func (t TopDownTraverser) VisitRegion(rn *RegionNode) {
	t.v.VisitRegion(rn)
	t.VisitBlockSlice(rn.Blocks)
	t.VisitInlineSlice(rn.Inlines)
}

// VisitHeading traverses the heading.
func (t TopDownTraverser) VisitHeading(hn *HeadingNode) {
	t.v.VisitHeading(hn)
	t.VisitInlineSlice(hn.Inlines)
}

// VisitHRule traverses nothing.
func (t TopDownTraverser) VisitHRule(hn *HRuleNode) { t.v.VisitHRule(hn) }

// VisitNestedList traverses all nested list elements.
func (t TopDownTraverser) VisitNestedList(ln *NestedListNode) {
	t.v.VisitNestedList(ln)
	for _, item := range ln.Items {
		t.visitItemSlice(item)
	}
}

// VisitDescriptionList traverses all description terms and their associated
// descriptions.
func (t TopDownTraverser) VisitDescriptionList(dn *DescriptionListNode) {
	t.v.VisitDescriptionList(dn)
	for _, defs := range dn.Descriptions {
		t.VisitInlineSlice(defs.Term)
		for _, descr := range defs.Descriptions {
			t.visitDescriptionSlice(descr)
		}
	}
}

// VisitPara traverses the inlines of a paragraph.
func (t TopDownTraverser) VisitPara(pn *ParaNode) {
	t.v.VisitPara(pn)
	t.VisitInlineSlice(pn.Inlines)
}

// VisitTable traverses all cells of the header and then row-wise all cells of
// the table body.
func (t TopDownTraverser) VisitTable(tn *TableNode) {
	t.v.VisitTable(tn)
	for _, col := range tn.Header {
		t.VisitInlineSlice(col.Inlines)
	}
	for _, row := range tn.Rows {
		for _, col := range row {
			t.VisitInlineSlice(col.Inlines)
		}
	}
}

// VisitBLOB traverses nothing.
func (t TopDownTraverser) VisitBLOB(bn *BLOBNode) { t.v.VisitBLOB(bn) }

// VisitText traverses nothing.
func (t TopDownTraverser) VisitText(tn *TextNode) { t.v.VisitText(tn) }

// VisitTag traverses nothing.
func (t TopDownTraverser) VisitTag(tn *TagNode) { t.v.VisitTag(tn) }

// VisitSpace traverses nothing.
func (t TopDownTraverser) VisitSpace(sn *SpaceNode) { t.v.VisitSpace(sn) }

// VisitBreak traverses nothing.
func (t TopDownTraverser) VisitBreak(bn *BreakNode) { t.v.VisitBreak(bn) }

// VisitLink traverses the link text.
func (t TopDownTraverser) VisitLink(ln *LinkNode) {
	t.v.VisitLink(ln)
	t.VisitInlineSlice(ln.Inlines)
}

// VisitImage traverses the image text.
func (t TopDownTraverser) VisitImage(in *ImageNode) {
	t.v.VisitImage(in)
	t.VisitInlineSlice(in.Inlines)
}

// VisitCite traverses the cite text.
func (t TopDownTraverser) VisitCite(cn *CiteNode) {
	t.v.VisitCite(cn)
	t.VisitInlineSlice(cn.Inlines)
}

// VisitFootnote traverses the footnote text.
func (t TopDownTraverser) VisitFootnote(fn *FootnoteNode) {
	t.v.VisitFootnote(fn)
	t.VisitInlineSlice(fn.Inlines)
}

// VisitMark traverses nothing.
func (t TopDownTraverser) VisitMark(mn *MarkNode) { t.v.VisitMark(mn) }

// VisitFormat traverses the formatted text.
func (t TopDownTraverser) VisitFormat(fn *FormatNode) {
	t.v.VisitFormat(fn)
	t.VisitInlineSlice(fn.Inlines)
}

// VisitLiteral traverses nothing.
func (t TopDownTraverser) VisitLiteral(ln *LiteralNode) { t.v.VisitLiteral(ln) }

// VisitBlockSlice traverses a block slice.
func (t TopDownTraverser) VisitBlockSlice(bns BlockSlice) {
	for _, bn := range bns {
		bn.Accept(t)
	}
}

func (t TopDownTraverser) visitItemSlice(ins ItemSlice) {
	for _, in := range ins {
		in.Accept(t)
	}
}

func (t TopDownTraverser) visitDescriptionSlice(dns DescriptionSlice) {
	for _, dn := range dns {
		dn.Accept(t)
	}
}

// VisitInlineSlice traverses a block slice.
func (t TopDownTraverser) VisitInlineSlice(ins InlineSlice) {
	for _, in := range ins {
		in.Accept(t)
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package ast provides the abstract syntax tree.
package ast

// Visitor is the interface all visitors must implement.
type Visitor interface {
	// Block nodes
	VisitVerbatim(vn *VerbatimNode)
	VisitRegion(rn *RegionNode)
	VisitHeading(hn *HeadingNode)
	VisitHRule(hn *HRuleNode)
	VisitNestedList(ln *NestedListNode)
	VisitDescriptionList(dn *DescriptionListNode)
	VisitPara(pn *ParaNode)
	VisitTable(tn *TableNode)
	VisitBLOB(bn *BLOBNode)

	// Inline nodes
	VisitText(tn *TextNode)
	VisitTag(tn *TagNode)
	VisitSpace(sn *SpaceNode)
	VisitBreak(bn *BreakNode)
	VisitLink(ln *LinkNode)
	VisitImage(in *ImageNode)
	VisitCite(cn *CiteNode)
	VisitFootnote(fn *FootnoteNode)
	VisitMark(mn *MarkNode)
	VisitFormat(fn *FormatNode)
	VisitLiteral(ln *LiteralNode)
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package ast provides the abstract syntax tree.
package ast

// Visitor is a visitor for walking the AST.
type Visitor interface {
	Visit(node Node) Visitor
}

// Walk traverses the AST.
func Walk(v Visitor, node Node) {
	if v = v.Visit(node); v == nil {
		return
	}
	node.WalkChildren(v)
	v.Visit(nil)
}

// WalkBlockSlice traverse a block slice.
func WalkBlockSlice(v Visitor, bns BlockSlice) {
	for _, bn := range bns {
		Walk(v, bn)
	}
}

// WalkInlineSlice traverses an inline slice.
func WalkInlineSlice(v Visitor, ins InlineSlice) {
	for _, in := range ins {
		Walk(v, in)
	}
}

// WalkItemSlice traverses an item slice.
func WalkItemSlice(v Visitor, ins ItemSlice) {
	for _, in := range ins {
		Walk(v, in)
	}
}

// WalkDescriptionSlice traverses an item slice.
func WalkDescriptionSlice(v Visitor, dns DescriptionSlice) {
	for _, dn := range dns {
		Walk(v, dn)
	}
}

// Package auth provides services for authentification / authorization.
package auth

import (
	"time"


	"zettelstore.de/z/config"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/place"
	"zettelstore.de/z/web/server"
)

// BaseManager allows to check some base auth modes.
type BaseManager interface {
	// IsReadonly returns true, if the systems is configured to run in read-only-mode.
	IsReadonly() bool
................................................................................
}

// Manager is the main interface for providing the service.
type Manager interface {
	TokenManager
	AuthzManager

	PlaceWithPolicy(auth server.Auth, unprotectedPlace place.Place, rtConfig config.Config) (place.Place, Policy)
}

// Policy is an interface for checking access authorization.
type Policy interface {
	// User is allowed to create a new zettel.
	CanCreate(user, newMeta *meta.Meta) bool

// Package auth provides services for authentification / authorization.
package auth

import (
	"time"

	"zettelstore.de/z/box"
	"zettelstore.de/z/config"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"

	"zettelstore.de/z/web/server"
)

// BaseManager allows to check some base auth modes.
type BaseManager interface {
	// IsReadonly returns true, if the systems is configured to run in read-only-mode.
	IsReadonly() bool
................................................................................
}

// Manager is the main interface for providing the service.
type Manager interface {
	TokenManager
	AuthzManager

	BoxWithPolicy(auth server.Auth, unprotectedBox box.Box, rtConfig config.Config) (box.Box, Policy)
}

// Policy is an interface for checking access authorization.
type Policy interface {
	// User is allowed to create a new zettel.
	CanCreate(user, newMeta *meta.Meta) bool

	"io"
	"time"

	"github.com/pascaldekloe/jwt"

	"zettelstore.de/z/auth"
	"zettelstore.de/z/auth/policy"

	"zettelstore.de/z/config"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/place"
	"zettelstore.de/z/web/server"
)

type myAuth struct {
	readonly bool
	owner    id.Zid
	secret   []byte
................................................................................
		if ur := meta.GetUserRole(val); ur != meta.UserRoleUnknown {
			return ur
		}
	}
	return meta.UserRoleReader
}

func (a *myAuth) PlaceWithPolicy(auth server.Auth, unprotectedPlace place.Place, rtConfig config.Config) (place.Place, auth.Policy) {
	return policy.PlaceWithPolicy(auth, a, unprotectedPlace, rtConfig)
}

	"io"
	"time"

	"github.com/pascaldekloe/jwt"

	"zettelstore.de/z/auth"
	"zettelstore.de/z/auth/policy"
	"zettelstore.de/z/box"
	"zettelstore.de/z/config"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/kernel"

	"zettelstore.de/z/web/server"
)

type myAuth struct {
	readonly bool
	owner    id.Zid
	secret   []byte
................................................................................
		if ur := meta.GetUserRole(val); ur != meta.UserRoleUnknown {
			return ur
		}
	}
	return meta.UserRoleReader
}

func (a *myAuth) BoxWithPolicy(auth server.Auth, unprotectedBox box.Box, rtConfig config.Config) (box.Box, auth.Policy) {
	return policy.BoxWithPolicy(auth, a, unprotectedBox, rtConfig)
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package policy provides some interfaces and implementation for authorizsation policies.
package policy

import (
	"context"

	"zettelstore.de/z/auth"
	"zettelstore.de/z/box"
	"zettelstore.de/z/config"
	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/search"
	"zettelstore.de/z/web/server"
)

// BoxWithPolicy wraps the given box inside a policy box.
func BoxWithPolicy(
	auth server.Auth,
	manager auth.AuthzManager,
	box box.Box,
	authConfig config.AuthConfig,
) (box.Box, auth.Policy) {
	pol := newPolicy(manager, authConfig)
	return newBox(auth, box, pol), pol
}

// polBox implements a policy box.
type polBox struct {
	auth   server.Auth
	box    box.Box
	policy auth.Policy
}

// newBox creates a new policy box.
func newBox(auth server.Auth, box box.Box, policy auth.Policy) box.Box {
	return &polBox{
		auth:   auth,
		box:    box,
		policy: policy,
	}
}

func (pp *polBox) Location() string {
	return pp.box.Location()
}

func (pp *polBox) CanCreateZettel(ctx context.Context) bool {
	return pp.box.CanCreateZettel(ctx)
}

func (pp *polBox) CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error) {
	user := pp.auth.GetUser(ctx)
	if pp.policy.CanCreate(user, zettel.Meta) {
		return pp.box.CreateZettel(ctx, zettel)
	}
	return id.Invalid, box.NewErrNotAllowed("Create", user, id.Invalid)
}

func (pp *polBox) GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
	zettel, err := pp.box.GetZettel(ctx, zid)
	if err != nil {
		return domain.Zettel{}, err
	}
	user := pp.auth.GetUser(ctx)
	if pp.policy.CanRead(user, zettel.Meta) {
		return zettel, nil
	}
	return domain.Zettel{}, box.NewErrNotAllowed("GetZettel", user, zid)
}

func (pp *polBox) GetAllZettel(ctx context.Context, zid id.Zid) ([]domain.Zettel, error) {
	return pp.box.GetAllZettel(ctx, zid)
}

func (pp *polBox) GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
	m, err := pp.box.GetMeta(ctx, zid)
	if err != nil {
		return nil, err
	}
	user := pp.auth.GetUser(ctx)
	if pp.policy.CanRead(user, m) {
		return m, nil
	}
	return nil, box.NewErrNotAllowed("GetMeta", user, zid)
}

func (pp *polBox) GetAllMeta(ctx context.Context, zid id.Zid) ([]*meta.Meta, error) {
	return pp.box.GetAllMeta(ctx, zid)
}

func (pp *polBox) FetchZids(ctx context.Context) (id.Set, error) {
	return nil, box.NewErrNotAllowed("fetch-zids", pp.auth.GetUser(ctx), id.Invalid)
}

func (pp *polBox) SelectMeta(ctx context.Context, s *search.Search) ([]*meta.Meta, error) {
	user := pp.auth.GetUser(ctx)
	canRead := pp.policy.CanRead
	s = s.AddPreMatch(func(m *meta.Meta) bool { return canRead(user, m) })
	return pp.box.SelectMeta(ctx, s)
}

func (pp *polBox) CanUpdateZettel(ctx context.Context, zettel domain.Zettel) bool {
	return pp.box.CanUpdateZettel(ctx, zettel)
}

func (pp *polBox) UpdateZettel(ctx context.Context, zettel domain.Zettel) error {
	zid := zettel.Meta.Zid
	user := pp.auth.GetUser(ctx)
	if !zid.IsValid() {
		return &box.ErrInvalidID{Zid: zid}
	}
	// Write existing zettel
	oldMeta, err := pp.box.GetMeta(ctx, zid)
	if err != nil {
		return err
	}
	if pp.policy.CanWrite(user, oldMeta, zettel.Meta) {
		return pp.box.UpdateZettel(ctx, zettel)
	}
	return box.NewErrNotAllowed("Write", user, zid)
}

func (pp *polBox) AllowRenameZettel(ctx context.Context, zid id.Zid) bool {
	return pp.box.AllowRenameZettel(ctx, zid)
}

func (pp *polBox) RenameZettel(ctx context.Context, curZid, newZid id.Zid) error {
	meta, err := pp.box.GetMeta(ctx, curZid)
	if err != nil {
		return err
	}
	user := pp.auth.GetUser(ctx)
	if pp.policy.CanRename(user, meta) {
		return pp.box.RenameZettel(ctx, curZid, newZid)
	}
	return box.NewErrNotAllowed("Rename", user, curZid)
}

func (pp *polBox) CanDeleteZettel(ctx context.Context, zid id.Zid) bool {
	return pp.box.CanDeleteZettel(ctx, zid)
}

func (pp *polBox) DeleteZettel(ctx context.Context, zid id.Zid) error {
	meta, err := pp.box.GetMeta(ctx, zid)
	if err != nil {
		return err
	}
	user := pp.auth.GetUser(ctx)
	if pp.policy.CanDelete(user, meta) {
		return pp.box.DeleteZettel(ctx, zid)
	}
	return box.NewErrNotAllowed("Delete", user, zid)
}

	if user == nil {
		return false
	}
	if role, ok := m.Get(meta.KeyRole); ok && role == meta.ValueRoleUser {
		// Only the user can read its own zettel
		return user.Zid == m.Zid
	}


	return true





}

var noChangeUser = []string{
	meta.KeyID,
	meta.KeyRole,
	meta.KeyUserID,
	meta.KeyUserRole,
................................................................................
		for _, key := range noChangeUser {
			if oldMeta.GetDefault(key, "") != newMeta.GetDefault(key, "") {
				return false
			}
		}
		return true
	}
	if o.manager.GetUserRole(user) == meta.UserRoleReader {

		return false
	}
	return o.userCanCreate(user, newMeta)
}

func (o *ownerPolicy) CanRename(user, m *meta.Meta) bool {
	if user == nil || !o.pre.CanRename(user, m) {

	if user == nil {
		return false
	}
	if role, ok := m.Get(meta.KeyRole); ok && role == meta.ValueRoleUser {
		// Only the user can read its own zettel
		return user.Zid == m.Zid
	}
	switch o.manager.GetUserRole(user) {
	case meta.UserRoleReader, meta.UserRoleWriter, meta.UserRoleOwner:
		return true
	case meta.UserRoleCreator:
		return vis == meta.VisibilityCreator
	default:
		return false
	}
}

var noChangeUser = []string{
	meta.KeyID,
	meta.KeyRole,
	meta.KeyUserID,
	meta.KeyUserRole,
................................................................................
		for _, key := range noChangeUser {
			if oldMeta.GetDefault(key, "") != newMeta.GetDefault(key, "") {
				return false
			}
		}
		return true
	}
	switch userRole := o.manager.GetUserRole(user); userRole {
	case meta.UserRoleReader, meta.UserRoleCreator:
		return false
	}
	return o.userCanCreate(user, newMeta)
}

func (o *ownerPolicy) CanRename(user, m *meta.Meta) bool {
	if user == nil || !o.pre.CanRename(user, m) {

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package policy provides some interfaces and implementation for authorizsation policies.
package policy

import (
	"context"
	"io"

	"zettelstore.de/z/auth"
	"zettelstore.de/z/config"
	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/place"
	"zettelstore.de/z/search"
	"zettelstore.de/z/web/server"
)

// PlaceWithPolicy wraps the given place inside a policy place.
func PlaceWithPolicy(
	auth server.Auth,
	manager auth.AuthzManager,
	place place.Place,
	authConfig config.AuthConfig,
) (place.Place, auth.Policy) {
	pol := newPolicy(manager, authConfig)
	return newPlace(auth, place, pol), pol
}

// polPlace implements a policy place.
type polPlace struct {
	auth   server.Auth
	place  place.Place
	policy auth.Policy
}

// newPlace creates a new policy place.
func newPlace(auth server.Auth, place place.Place, policy auth.Policy) place.Place {
	return &polPlace{
		auth:   auth,
		place:  place,
		policy: policy,
	}
}

func (pp *polPlace) Location() string {
	return pp.place.Location()
}

func (pp *polPlace) CanCreateZettel(ctx context.Context) bool {
	return pp.place.CanCreateZettel(ctx)
}

func (pp *polPlace) CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error) {
	user := pp.auth.GetUser(ctx)
	if pp.policy.CanCreate(user, zettel.Meta) {
		return pp.place.CreateZettel(ctx, zettel)
	}
	return id.Invalid, place.NewErrNotAllowed("Create", user, id.Invalid)
}

func (pp *polPlace) GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
	zettel, err := pp.place.GetZettel(ctx, zid)
	if err != nil {
		return domain.Zettel{}, err
	}
	user := pp.auth.GetUser(ctx)
	if pp.policy.CanRead(user, zettel.Meta) {
		return zettel, nil
	}
	return domain.Zettel{}, place.NewErrNotAllowed("GetZettel", user, zid)
}

func (pp *polPlace) GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
	m, err := pp.place.GetMeta(ctx, zid)
	if err != nil {
		return nil, err
	}
	user := pp.auth.GetUser(ctx)
	if pp.policy.CanRead(user, m) {
		return m, nil
	}
	return nil, place.NewErrNotAllowed("GetMeta", user, zid)
}

func (pp *polPlace) FetchZids(ctx context.Context) (id.Set, error) {
	return nil, place.NewErrNotAllowed("fetch-zids", pp.auth.GetUser(ctx), id.Invalid)
}

func (pp *polPlace) SelectMeta(ctx context.Context, s *search.Search) ([]*meta.Meta, error) {
	user := pp.auth.GetUser(ctx)
	canRead := pp.policy.CanRead
	s = s.AddPreMatch(func(m *meta.Meta) bool { return canRead(user, m) })
	return pp.place.SelectMeta(ctx, s)
}

func (pp *polPlace) CanUpdateZettel(ctx context.Context, zettel domain.Zettel) bool {
	return pp.place.CanUpdateZettel(ctx, zettel)
}

func (pp *polPlace) UpdateZettel(ctx context.Context, zettel domain.Zettel) error {
	zid := zettel.Meta.Zid
	user := pp.auth.GetUser(ctx)
	if !zid.IsValid() {
		return &place.ErrInvalidID{Zid: zid}
	}
	// Write existing zettel
	oldMeta, err := pp.place.GetMeta(ctx, zid)
	if err != nil {
		return err
	}
	if pp.policy.CanWrite(user, oldMeta, zettel.Meta) {
		return pp.place.UpdateZettel(ctx, zettel)
	}
	return place.NewErrNotAllowed("Write", user, zid)
}

func (pp *polPlace) AllowRenameZettel(ctx context.Context, zid id.Zid) bool {
	return pp.place.AllowRenameZettel(ctx, zid)
}

func (pp *polPlace) RenameZettel(ctx context.Context, curZid, newZid id.Zid) error {
	meta, err := pp.place.GetMeta(ctx, curZid)
	if err != nil {
		return err
	}
	user := pp.auth.GetUser(ctx)
	if pp.policy.CanRename(user, meta) {
		return pp.place.RenameZettel(ctx, curZid, newZid)
	}
	return place.NewErrNotAllowed("Rename", user, curZid)
}

func (pp *polPlace) CanDeleteZettel(ctx context.Context, zid id.Zid) bool {
	return pp.place.CanDeleteZettel(ctx, zid)
}

func (pp *polPlace) DeleteZettel(ctx context.Context, zid id.Zid) error {
	meta, err := pp.place.GetMeta(ctx, zid)
	if err != nil {
		return err
	}
	user := pp.auth.GetUser(ctx)
	if pp.policy.CanDelete(user, meta) {
		return pp.place.DeleteZettel(ctx, zid)
	}
	return place.NewErrNotAllowed("Delete", user, zid)
}

func (pp *polPlace) ReadStats(st *place.Stats) {
	pp.place.ReadStats(st)
}

func (pp *polPlace) Dump(w io.Writer) {
	pp.place.Dump(w)
}

	"zettelstore.de/z/auth"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
)

func TestPolicies(t *testing.T) {

	testScene := []struct {
		readonly bool
		withAuth bool
		expert   bool
	}{
		{true, true, true},
		{true, true, false},
................................................................................

type authConfig struct{ expert bool }

func (ac *authConfig) GetExpertMode() bool { return ac.expert }

func (ac *authConfig) GetVisibility(m *meta.Meta) meta.Visibility {
	if vis, ok := m.Get(meta.KeyVisibility); ok {
		switch vis {
		case meta.ValueVisibilityPublic:
			return meta.VisibilityPublic
		case meta.ValueVisibilityOwner:
			return meta.VisibilityOwner
		case meta.ValueVisibilityExpert:
			return meta.VisibilityExpert
		}
	}
	return meta.VisibilityLogin
}

func testCreate(t *testing.T, pol auth.Policy, withAuth, readonly, isExpert bool) {
	t.Helper()
	anonUser := newAnon()

	reader := newReader()
	writer := newWriter()
	owner := newOwner()
	owner2 := newOwner2()
	zettel := newZettel()
	userZettel := newUserZettel()
	testCases := []struct {
		user *meta.Meta
		meta *meta.Meta
		exp  bool
	}{
		// No meta
		{anonUser, nil, false},

		{reader, nil, false},
		{writer, nil, false},
		{owner, nil, false},
		{owner2, nil, false},
		// Ordinary zettel
		{anonUser, zettel, !withAuth && !readonly},

		{reader, zettel, !withAuth && !readonly},
		{writer, zettel, !readonly},
		{owner, zettel, !readonly},
		{owner2, zettel, !readonly},
		// User zettel
		{anonUser, userZettel, !withAuth && !readonly},

		{reader, userZettel, !withAuth && !readonly},
		{writer, userZettel, !withAuth && !readonly},
		{owner, userZettel, !readonly},
		{owner2, userZettel, !readonly},
	}
	for _, tc := range testCases {
		t.Run("Create", func(tt *testing.T) {
................................................................................
		})
	}
}

func testRead(t *testing.T, pol auth.Policy, withAuth, readonly, expert bool) {
	t.Helper()
	anonUser := newAnon()

	reader := newReader()
	writer := newWriter()
	owner := newOwner()
	owner2 := newOwner2()
	zettel := newZettel()
	publicZettel := newPublicZettel()

	loginZettel := newLoginZettel()
	ownerZettel := newOwnerZettel()
	expertZettel := newExpertZettel()
	userZettel := newUserZettel()
	testCases := []struct {
		user *meta.Meta
		meta *meta.Meta
		exp  bool
	}{
		// No meta
		{anonUser, nil, false},

		{reader, nil, false},
		{writer, nil, false},
		{owner, nil, false},
		{owner2, nil, false},
		// Ordinary zettel
		{anonUser, zettel, !withAuth},

		{reader, zettel, true},
		{writer, zettel, true},
		{owner, zettel, true},
		{owner2, zettel, true},
		// Public zettel
		{anonUser, publicZettel, true},

		{reader, publicZettel, true},
		{writer, publicZettel, true},
		{owner, publicZettel, true},
		{owner2, publicZettel, true},







		// Login zettel
		{anonUser, loginZettel, !withAuth},

		{reader, loginZettel, true},
		{writer, loginZettel, true},
		{owner, loginZettel, true},
		{owner2, loginZettel, true},
		// Owner zettel
		{anonUser, ownerZettel, !withAuth},

		{reader, ownerZettel, !withAuth},
		{writer, ownerZettel, !withAuth},
		{owner, ownerZettel, true},
		{owner2, ownerZettel, true},
		// Expert zettel
		{anonUser, expertZettel, !withAuth && expert},

		{reader, expertZettel, !withAuth && expert},
		{writer, expertZettel, !withAuth && expert},
		{owner, expertZettel, expert},
		{owner2, expertZettel, expert},
		// Other user zettel
		{anonUser, userZettel, !withAuth},

		{reader, userZettel, !withAuth},
		{writer, userZettel, !withAuth},
		{owner, userZettel, true},
		{owner2, userZettel, true},
		// Own user zettel

		{reader, reader, true},
		{writer, writer, true},
		{owner, owner, true},
		{owner, owner2, true},
		{owner2, owner, true},
		{owner2, owner2, true},
	}
................................................................................
		})
	}
}

func testWrite(t *testing.T, pol auth.Policy, withAuth, readonly, expert bool) {
	t.Helper()
	anonUser := newAnon()

	reader := newReader()
	writer := newWriter()
	owner := newOwner()
	owner2 := newOwner2()
	zettel := newZettel()
	publicZettel := newPublicZettel()
	loginZettel := newLoginZettel()
................................................................................
		user *meta.Meta
		old  *meta.Meta
		new  *meta.Meta
		exp  bool
	}{
		// No old and new meta
		{anonUser, nil, nil, false},

		{reader, nil, nil, false},
		{writer, nil, nil, false},
		{owner, nil, nil, false},
		{owner2, nil, nil, false},
		// No old meta
		{anonUser, nil, zettel, false},

		{reader, nil, zettel, false},
		{writer, nil, zettel, false},
		{owner, nil, zettel, false},
		{owner2, nil, zettel, false},
		// No new meta
		{anonUser, zettel, nil, false},

		{reader, zettel, nil, false},
		{writer, zettel, nil, false},
		{owner, zettel, nil, false},
		{owner2, zettel, nil, false},
		// Old an new zettel have different zettel identifier
		{anonUser, zettel, publicZettel, false},

		{reader, zettel, publicZettel, false},
		{writer, zettel, publicZettel, false},
		{owner, zettel, publicZettel, false},
		{owner2, zettel, publicZettel, false},
		// Overwrite a normal zettel
		{anonUser, zettel, zettel, notAuthNotReadonly},

		{reader, zettel, zettel, notAuthNotReadonly},
		{writer, zettel, zettel, !readonly},
		{owner, zettel, zettel, !readonly},
		{owner2, zettel, zettel, !readonly},
		// Public zettel
		{anonUser, publicZettel, publicZettel, notAuthNotReadonly},

		{reader, publicZettel, publicZettel, notAuthNotReadonly},
		{writer, publicZettel, publicZettel, !readonly},
		{owner, publicZettel, publicZettel, !readonly},
		{owner2, publicZettel, publicZettel, !readonly},
		// Login zettel
		{anonUser, loginZettel, loginZettel, notAuthNotReadonly},

		{reader, loginZettel, loginZettel, notAuthNotReadonly},
		{writer, loginZettel, loginZettel, !readonly},
		{owner, loginZettel, loginZettel, !readonly},
		{owner2, loginZettel, loginZettel, !readonly},
		// Owner zettel
		{anonUser, ownerZettel, ownerZettel, notAuthNotReadonly},

		{reader, ownerZettel, ownerZettel, notAuthNotReadonly},
		{writer, ownerZettel, ownerZettel, notAuthNotReadonly},
		{owner, ownerZettel, ownerZettel, !readonly},
		{owner2, ownerZettel, ownerZettel, !readonly},
		// Expert zettel
		{anonUser, expertZettel, expertZettel, notAuthNotReadonly && expert},

		{reader, expertZettel, expertZettel, notAuthNotReadonly && expert},
		{writer, expertZettel, expertZettel, notAuthNotReadonly && expert},
		{owner, expertZettel, expertZettel, !readonly && expert},
		{owner2, expertZettel, expertZettel, !readonly && expert},
		// Other user zettel
		{anonUser, userZettel, userZettel, notAuthNotReadonly},

		{reader, userZettel, userZettel, notAuthNotReadonly},
		{writer, userZettel, userZettel, notAuthNotReadonly},
		{owner, userZettel, userZettel, !readonly},
		{owner2, userZettel, userZettel, !readonly},
		// Own user zettel

		{reader, reader, reader, !readonly},
		{writer, writer, writer, !readonly},
		{owner, owner, owner, !readonly},
		{owner2, owner2, owner2, !readonly},
		// Writer cannot change importand metadata of its own user zettel
		{writer, writer, writerNew, notAuthNotReadonly},
		// No r/o zettel
		{anonUser, roFalse, roFalse, notAuthNotReadonly},

		{reader, roFalse, roFalse, notAuthNotReadonly},
		{writer, roFalse, roFalse, !readonly},
		{owner, roFalse, roFalse, !readonly},
		{owner2, roFalse, roFalse, !readonly},
		// Reader r/o zettel
		{anonUser, roReader, roReader, false},

		{reader, roReader, roReader, false},
		{writer, roReader, roReader, !readonly},
		{owner, roReader, roReader, !readonly},
		{owner2, roReader, roReader, !readonly},
		// Writer r/o zettel
		{anonUser, roWriter, roWriter, false},

		{reader, roWriter, roWriter, false},
		{writer, roWriter, roWriter, false},
		{owner, roWriter, roWriter, !readonly},
		{owner2, roWriter, roWriter, !readonly},
		// Owner r/o zettel
		{anonUser, roOwner, roOwner, false},

		{reader, roOwner, roOwner, false},
		{writer, roOwner, roOwner, false},
		{owner, roOwner, roOwner, false},
		{owner2, roOwner, roOwner, false},
		// r/o = true zettel
		{anonUser, roTrue, roTrue, false},

		{reader, roTrue, roTrue, false},
		{writer, roTrue, roTrue, false},
		{owner, roTrue, roTrue, false},
		{owner2, roTrue, roTrue, false},
	}
	for _, tc := range testCases {
		t.Run("Write", func(tt *testing.T) {
................................................................................
		})
	}
}

func testRename(t *testing.T, pol auth.Policy, withAuth, readonly, expert bool) {
	t.Helper()
	anonUser := newAnon()

	reader := newReader()
	writer := newWriter()
	owner := newOwner()
	owner2 := newOwner2()
	zettel := newZettel()
	expertZettel := newExpertZettel()
	roFalse := newRoFalseZettel()
................................................................................
	testCases := []struct {
		user *meta.Meta
		meta *meta.Meta
		exp  bool
	}{
		// No meta
		{anonUser, nil, false},

		{reader, nil, false},
		{writer, nil, false},
		{owner, nil, false},
		{owner2, nil, false},
		// Any zettel
		{anonUser, zettel, notAuthNotReadonly},

		{reader, zettel, notAuthNotReadonly},
		{writer, zettel, notAuthNotReadonly},
		{owner, zettel, !readonly},
		{owner2, zettel, !readonly},
		// Expert zettel
		{anonUser, expertZettel, notAuthNotReadonly && expert},

		{reader, expertZettel, notAuthNotReadonly && expert},
		{writer, expertZettel, notAuthNotReadonly && expert},
		{owner, expertZettel, !readonly && expert},
		{owner2, expertZettel, !readonly && expert},
		// No r/o zettel
		{anonUser, roFalse, notAuthNotReadonly},

		{reader, roFalse, notAuthNotReadonly},
		{writer, roFalse, notAuthNotReadonly},
		{owner, roFalse, !readonly},
		{owner2, roFalse, !readonly},
		// Reader r/o zettel
		{anonUser, roReader, false},

		{reader, roReader, false},
		{writer, roReader, notAuthNotReadonly},
		{owner, roReader, !readonly},
		{owner2, roReader, !readonly},
		// Writer r/o zettel
		{anonUser, roWriter, false},

		{reader, roWriter, false},
		{writer, roWriter, false},
		{owner, roWriter, !readonly},
		{owner2, roWriter, !readonly},
		// Owner r/o zettel
		{anonUser, roOwner, false},

		{reader, roOwner, false},
		{writer, roOwner, false},
		{owner, roOwner, false},
		{owner2, roOwner, false},
		// r/o = true zettel
		{anonUser, roTrue, false},

		{reader, roTrue, false},
		{writer, roTrue, false},
		{owner, roTrue, false},
		{owner2, roTrue, false},
	}
	for _, tc := range testCases {
		t.Run("Rename", func(tt *testing.T) {
................................................................................
		})
	}
}

func testDelete(t *testing.T, pol auth.Policy, withAuth, readonly, expert bool) {
	t.Helper()
	anonUser := newAnon()

	reader := newReader()
	writer := newWriter()
	owner := newOwner()
	owner2 := newOwner2()
	zettel := newZettel()
	expertZettel := newExpertZettel()
	roFalse := newRoFalseZettel()
................................................................................
	testCases := []struct {
		user *meta.Meta
		meta *meta.Meta
		exp  bool
	}{
		// No meta
		{anonUser, nil, false},

		{reader, nil, false},
		{writer, nil, false},
		{owner, nil, false},
		{owner2, nil, false},
		// Any zettel
		{anonUser, zettel, notAuthNotReadonly},

		{reader, zettel, notAuthNotReadonly},
		{writer, zettel, notAuthNotReadonly},
		{owner, zettel, !readonly},
		{owner2, zettel, !readonly},
		// Expert zettel
		{anonUser, expertZettel, notAuthNotReadonly && expert},

		{reader, expertZettel, notAuthNotReadonly && expert},
		{writer, expertZettel, notAuthNotReadonly && expert},
		{owner, expertZettel, !readonly && expert},
		{owner2, expertZettel, !readonly && expert},
		// No r/o zettel
		{anonUser, roFalse, notAuthNotReadonly},

		{reader, roFalse, notAuthNotReadonly},
		{writer, roFalse, notAuthNotReadonly},
		{owner, roFalse, !readonly},
		{owner2, roFalse, !readonly},
		// Reader r/o zettel
		{anonUser, roReader, false},

		{reader, roReader, false},
		{writer, roReader, notAuthNotReadonly},
		{owner, roReader, !readonly},
		{owner2, roReader, !readonly},
		// Writer r/o zettel
		{anonUser, roWriter, false},

		{reader, roWriter, false},
		{writer, roWriter, false},
		{owner, roWriter, !readonly},
		{owner2, roWriter, !readonly},
		// Owner r/o zettel
		{anonUser, roOwner, false},

		{reader, roOwner, false},
		{writer, roOwner, false},
		{owner, roOwner, false},
		{owner2, roOwner, false},
		// r/o = true zettel
		{anonUser, roTrue, false},

		{reader, roTrue, false},
		{writer, roTrue, false},
		{owner, roTrue, false},
		{owner2, roTrue, false},
	}
	for _, tc := range testCases {
		t.Run("Delete", func(tt *testing.T) {
................................................................................
				tt.Errorf("exp=%v, but got=%v", tc.exp, got)
			}
		})
	}
}

const (
	readerZid = id.Zid(1013)
	writerZid = id.Zid(1015)
	ownerZid  = id.Zid(1017)

	owner2Zid = id.Zid(1019)
	zettelZid = id.Zid(1021)
	visZid    = id.Zid(1023)
	userZid   = id.Zid(1025)
)

func newAnon() *meta.Meta { return nil }







func newReader() *meta.Meta {
	user := meta.New(readerZid)
	user.Set(meta.KeyTitle, "Reader")
	user.Set(meta.KeyRole, meta.ValueRoleUser)
	user.Set(meta.KeyUserRole, meta.ValueUserRoleReader)
	return user
}
................................................................................
	return m
}
func newPublicZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Public Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityPublic)
	return m






}
func newLoginZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Login Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityLogin)
	return m
}

	"zettelstore.de/z/auth"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
)

func TestPolicies(t *testing.T) {
	t.Parallel()
	testScene := []struct {
		readonly bool
		withAuth bool
		expert   bool
	}{
		{true, true, true},
		{true, true, false},
................................................................................

type authConfig struct{ expert bool }

func (ac *authConfig) GetExpertMode() bool { return ac.expert }

func (ac *authConfig) GetVisibility(m *meta.Meta) meta.Visibility {
	if vis, ok := m.Get(meta.KeyVisibility); ok {




		return meta.GetVisibility(vis)



	}
	return meta.VisibilityLogin
}

func testCreate(t *testing.T, pol auth.Policy, withAuth, readonly, isExpert bool) {
	t.Helper()
	anonUser := newAnon()
	creator := newCreator()
	reader := newReader()
	writer := newWriter()
	owner := newOwner()
	owner2 := newOwner2()
	zettel := newZettel()
	userZettel := newUserZettel()
	testCases := []struct {
		user *meta.Meta
		meta *meta.Meta
		exp  bool
	}{
		// No meta
		{anonUser, nil, false},
		{creator, nil, false},
		{reader, nil, false},
		{writer, nil, false},
		{owner, nil, false},
		{owner2, nil, false},
		// Ordinary zettel
		{anonUser, zettel, !withAuth && !readonly},
		{creator, zettel, !readonly},
		{reader, zettel, !withAuth && !readonly},
		{writer, zettel, !readonly},
		{owner, zettel, !readonly},
		{owner2, zettel, !readonly},
		// User zettel
		{anonUser, userZettel, !withAuth && !readonly},
		{creator, userZettel, !withAuth && !readonly},
		{reader, userZettel, !withAuth && !readonly},
		{writer, userZettel, !withAuth && !readonly},
		{owner, userZettel, !readonly},
		{owner2, userZettel, !readonly},
	}
	for _, tc := range testCases {
		t.Run("Create", func(tt *testing.T) {
................................................................................
		})
	}
}

func testRead(t *testing.T, pol auth.Policy, withAuth, readonly, expert bool) {
	t.Helper()
	anonUser := newAnon()
	creator := newCreator()
	reader := newReader()
	writer := newWriter()
	owner := newOwner()
	owner2 := newOwner2()
	zettel := newZettel()
	publicZettel := newPublicZettel()
	creatorZettel := newCreatorZettel()
	loginZettel := newLoginZettel()
	ownerZettel := newOwnerZettel()
	expertZettel := newExpertZettel()
	userZettel := newUserZettel()
	testCases := []struct {
		user *meta.Meta
		meta *meta.Meta
		exp  bool
	}{
		// No meta
		{anonUser, nil, false},
		{creator, nil, false},
		{reader, nil, false},
		{writer, nil, false},
		{owner, nil, false},
		{owner2, nil, false},
		// Ordinary zettel
		{anonUser, zettel, !withAuth},
		{creator, zettel, !withAuth},
		{reader, zettel, true},
		{writer, zettel, true},
		{owner, zettel, true},
		{owner2, zettel, true},
		// Public zettel
		{anonUser, publicZettel, true},
		{creator, publicZettel, true},
		{reader, publicZettel, true},
		{writer, publicZettel, true},
		{owner, publicZettel, true},
		{owner2, publicZettel, true},
		// Creator zettel
		{anonUser, creatorZettel, !withAuth},
		{creator, creatorZettel, true},
		{reader, creatorZettel, true},
		{writer, creatorZettel, true},
		{owner, creatorZettel, true},
		{owner2, creatorZettel, true},
		// Login zettel
		{anonUser, loginZettel, !withAuth},
		{creator, loginZettel, !withAuth},
		{reader, loginZettel, true},
		{writer, loginZettel, true},
		{owner, loginZettel, true},
		{owner2, loginZettel, true},
		// Owner zettel
		{anonUser, ownerZettel, !withAuth},
		{creator, ownerZettel, !withAuth},
		{reader, ownerZettel, !withAuth},
		{writer, ownerZettel, !withAuth},
		{owner, ownerZettel, true},
		{owner2, ownerZettel, true},
		// Expert zettel
		{anonUser, expertZettel, !withAuth && expert},
		{creator, expertZettel, !withAuth && expert},
		{reader, expertZettel, !withAuth && expert},
		{writer, expertZettel, !withAuth && expert},
		{owner, expertZettel, expert},
		{owner2, expertZettel, expert},
		// Other user zettel
		{anonUser, userZettel, !withAuth},
		{creator, userZettel, !withAuth},
		{reader, userZettel, !withAuth},
		{writer, userZettel, !withAuth},
		{owner, userZettel, true},
		{owner2, userZettel, true},
		// Own user zettel
		{creator, creator, true},
		{reader, reader, true},
		{writer, writer, true},
		{owner, owner, true},
		{owner, owner2, true},
		{owner2, owner, true},
		{owner2, owner2, true},
	}
................................................................................
		})
	}
}

func testWrite(t *testing.T, pol auth.Policy, withAuth, readonly, expert bool) {
	t.Helper()
	anonUser := newAnon()
	creator := newCreator()
	reader := newReader()
	writer := newWriter()
	owner := newOwner()
	owner2 := newOwner2()
	zettel := newZettel()
	publicZettel := newPublicZettel()
	loginZettel := newLoginZettel()
................................................................................
		user *meta.Meta
		old  *meta.Meta
		new  *meta.Meta
		exp  bool
	}{
		// No old and new meta
		{anonUser, nil, nil, false},
		{creator, nil, nil, false},
		{reader, nil, nil, false},
		{writer, nil, nil, false},
		{owner, nil, nil, false},
		{owner2, nil, nil, false},
		// No old meta
		{anonUser, nil, zettel, false},
		{creator, nil, zettel, false},
		{reader, nil, zettel, false},
		{writer, nil, zettel, false},
		{owner, nil, zettel, false},
		{owner2, nil, zettel, false},
		// No new meta
		{anonUser, zettel, nil, false},
		{creator, zettel, nil, false},
		{reader, zettel, nil, false},
		{writer, zettel, nil, false},
		{owner, zettel, nil, false},
		{owner2, zettel, nil, false},
		// Old an new zettel have different zettel identifier
		{anonUser, zettel, publicZettel, false},
		{creator, zettel, publicZettel, false},
		{reader, zettel, publicZettel, false},
		{writer, zettel, publicZettel, false},
		{owner, zettel, publicZettel, false},
		{owner2, zettel, publicZettel, false},
		// Overwrite a normal zettel
		{anonUser, zettel, zettel, notAuthNotReadonly},
		{creator, zettel, zettel, notAuthNotReadonly},
		{reader, zettel, zettel, notAuthNotReadonly},
		{writer, zettel, zettel, !readonly},
		{owner, zettel, zettel, !readonly},
		{owner2, zettel, zettel, !readonly},
		// Public zettel
		{anonUser, publicZettel, publicZettel, notAuthNotReadonly},
		{creator, publicZettel, publicZettel, notAuthNotReadonly},
		{reader, publicZettel, publicZettel, notAuthNotReadonly},
		{writer, publicZettel, publicZettel, !readonly},
		{owner, publicZettel, publicZettel, !readonly},
		{owner2, publicZettel, publicZettel, !readonly},
		// Login zettel
		{anonUser, loginZettel, loginZettel, notAuthNotReadonly},
		{creator, loginZettel, loginZettel, notAuthNotReadonly},
		{reader, loginZettel, loginZettel, notAuthNotReadonly},
		{writer, loginZettel, loginZettel, !readonly},
		{owner, loginZettel, loginZettel, !readonly},
		{owner2, loginZettel, loginZettel, !readonly},
		// Owner zettel
		{anonUser, ownerZettel, ownerZettel, notAuthNotReadonly},
		{creator, ownerZettel, ownerZettel, notAuthNotReadonly},
		{reader, ownerZettel, ownerZettel, notAuthNotReadonly},
		{writer, ownerZettel, ownerZettel, notAuthNotReadonly},
		{owner, ownerZettel, ownerZettel, !readonly},
		{owner2, ownerZettel, ownerZettel, !readonly},
		// Expert zettel
		{anonUser, expertZettel, expertZettel, notAuthNotReadonly && expert},
		{creator, expertZettel, expertZettel, notAuthNotReadonly && expert},
		{reader, expertZettel, expertZettel, notAuthNotReadonly && expert},
		{writer, expertZettel, expertZettel, notAuthNotReadonly && expert},
		{owner, expertZettel, expertZettel, !readonly && expert},
		{owner2, expertZettel, expertZettel, !readonly && expert},
		// Other user zettel
		{anonUser, userZettel, userZettel, notAuthNotReadonly},
		{creator, userZettel, userZettel, notAuthNotReadonly},
		{reader, userZettel, userZettel, notAuthNotReadonly},
		{writer, userZettel, userZettel, notAuthNotReadonly},
		{owner, userZettel, userZettel, !readonly},
		{owner2, userZettel, userZettel, !readonly},
		// Own user zettel
		{creator, creator, creator, !readonly},
		{reader, reader, reader, !readonly},
		{writer, writer, writer, !readonly},
		{owner, owner, owner, !readonly},
		{owner2, owner2, owner2, !readonly},
		// Writer cannot change importand metadata of its own user zettel
		{writer, writer, writerNew, notAuthNotReadonly},
		// No r/o zettel
		{anonUser, roFalse, roFalse, notAuthNotReadonly},
		{creator, roFalse, roFalse, notAuthNotReadonly},
		{reader, roFalse, roFalse, notAuthNotReadonly},
		{writer, roFalse, roFalse, !readonly},
		{owner, roFalse, roFalse, !readonly},
		{owner2, roFalse, roFalse, !readonly},
		// Reader r/o zettel
		{anonUser, roReader, roReader, false},
		{creator, roReader, roReader, false},
		{reader, roReader, roReader, false},
		{writer, roReader, roReader, !readonly},
		{owner, roReader, roReader, !readonly},
		{owner2, roReader, roReader, !readonly},
		// Writer r/o zettel
		{anonUser, roWriter, roWriter, false},
		{creator, roWriter, roWriter, false},
		{reader, roWriter, roWriter, false},
		{writer, roWriter, roWriter, false},
		{owner, roWriter, roWriter, !readonly},
		{owner2, roWriter, roWriter, !readonly},
		// Owner r/o zettel
		{anonUser, roOwner, roOwner, false},
		{creator, roOwner, roOwner, false},
		{reader, roOwner, roOwner, false},
		{writer, roOwner, roOwner, false},
		{owner, roOwner, roOwner, false},
		{owner2, roOwner, roOwner, false},
		// r/o = true zettel
		{anonUser, roTrue, roTrue, false},
		{creator, roTrue, roTrue, false},
		{reader, roTrue, roTrue, false},
		{writer, roTrue, roTrue, false},
		{owner, roTrue, roTrue, false},
		{owner2, roTrue, roTrue, false},
	}
	for _, tc := range testCases {
		t.Run("Write", func(tt *testing.T) {
................................................................................
		})
	}
}

func testRename(t *testing.T, pol auth.Policy, withAuth, readonly, expert bool) {
	t.Helper()
	anonUser := newAnon()
	creator := newCreator()
	reader := newReader()
	writer := newWriter()
	owner := newOwner()
	owner2 := newOwner2()
	zettel := newZettel()
	expertZettel := newExpertZettel()
	roFalse := newRoFalseZettel()
................................................................................
	testCases := []struct {
		user *meta.Meta
		meta *meta.Meta
		exp  bool
	}{
		// No meta
		{anonUser, nil, false},
		{creator, nil, false},
		{reader, nil, false},
		{writer, nil, false},
		{owner, nil, false},
		{owner2, nil, false},
		// Any zettel
		{anonUser, zettel, notAuthNotReadonly},
		{creator, zettel, notAuthNotReadonly},
		{reader, zettel, notAuthNotReadonly},
		{writer, zettel, notAuthNotReadonly},
		{owner, zettel, !readonly},
		{owner2, zettel, !readonly},
		// Expert zettel
		{anonUser, expertZettel, notAuthNotReadonly && expert},
		{creator, expertZettel, notAuthNotReadonly && expert},
		{reader, expertZettel, notAuthNotReadonly && expert},
		{writer, expertZettel, notAuthNotReadonly && expert},
		{owner, expertZettel, !readonly && expert},
		{owner2, expertZettel, !readonly && expert},
		// No r/o zettel
		{anonUser, roFalse, notAuthNotReadonly},
		{creator, roFalse, notAuthNotReadonly},
		{reader, roFalse, notAuthNotReadonly},
		{writer, roFalse, notAuthNotReadonly},
		{owner, roFalse, !readonly},
		{owner2, roFalse, !readonly},
		// Reader r/o zettel
		{anonUser, roReader, false},
		{creator, roReader, false},
		{reader, roReader, false},
		{writer, roReader, notAuthNotReadonly},
		{owner, roReader, !readonly},
		{owner2, roReader, !readonly},
		// Writer r/o zettel
		{anonUser, roWriter, false},
		{creator, roWriter, false},
		{reader, roWriter, false},
		{writer, roWriter, false},
		{owner, roWriter, !readonly},
		{owner2, roWriter, !readonly},
		// Owner r/o zettel
		{anonUser, roOwner, false},
		{creator, roOwner, false},
		{reader, roOwner, false},
		{writer, roOwner, false},
		{owner, roOwner, false},
		{owner2, roOwner, false},
		// r/o = true zettel
		{anonUser, roTrue, false},
		{creator, roTrue, false},
		{reader, roTrue, false},
		{writer, roTrue, false},
		{owner, roTrue, false},
		{owner2, roTrue, false},
	}
	for _, tc := range testCases {
		t.Run("Rename", func(tt *testing.T) {
................................................................................
		})
	}
}

func testDelete(t *testing.T, pol auth.Policy, withAuth, readonly, expert bool) {
	t.Helper()
	anonUser := newAnon()
	creator := newCreator()
	reader := newReader()
	writer := newWriter()
	owner := newOwner()
	owner2 := newOwner2()
	zettel := newZettel()
	expertZettel := newExpertZettel()
	roFalse := newRoFalseZettel()
................................................................................
	testCases := []struct {
		user *meta.Meta
		meta *meta.Meta
		exp  bool
	}{
		// No meta
		{anonUser, nil, false},
		{creator, nil, false},
		{reader, nil, false},
		{writer, nil, false},
		{owner, nil, false},
		{owner2, nil, false},
		// Any zettel
		{anonUser, zettel, notAuthNotReadonly},
		{creator, zettel, notAuthNotReadonly},
		{reader, zettel, notAuthNotReadonly},
		{writer, zettel, notAuthNotReadonly},
		{owner, zettel, !readonly},
		{owner2, zettel, !readonly},
		// Expert zettel
		{anonUser, expertZettel, notAuthNotReadonly && expert},
		{creator, expertZettel, notAuthNotReadonly && expert},
		{reader, expertZettel, notAuthNotReadonly && expert},
		{writer, expertZettel, notAuthNotReadonly && expert},
		{owner, expertZettel, !readonly && expert},
		{owner2, expertZettel, !readonly && expert},
		// No r/o zettel
		{anonUser, roFalse, notAuthNotReadonly},
		{creator, roFalse, notAuthNotReadonly},
		{reader, roFalse, notAuthNotReadonly},
		{writer, roFalse, notAuthNotReadonly},
		{owner, roFalse, !readonly},
		{owner2, roFalse, !readonly},
		// Reader r/o zettel
		{anonUser, roReader, false},
		{creator, roReader, false},
		{reader, roReader, false},
		{writer, roReader, notAuthNotReadonly},
		{owner, roReader, !readonly},
		{owner2, roReader, !readonly},
		// Writer r/o zettel
		{anonUser, roWriter, false},
		{creator, roWriter, false},
		{reader, roWriter, false},
		{writer, roWriter, false},
		{owner, roWriter, !readonly},
		{owner2, roWriter, !readonly},
		// Owner r/o zettel
		{anonUser, roOwner, false},
		{creator, roOwner, false},
		{reader, roOwner, false},
		{writer, roOwner, false},
		{owner, roOwner, false},
		{owner2, roOwner, false},
		// r/o = true zettel
		{anonUser, roTrue, false},
		{creator, roTrue, false},
		{reader, roTrue, false},
		{writer, roTrue, false},
		{owner, roTrue, false},
		{owner2, roTrue, false},
	}
	for _, tc := range testCases {
		t.Run("Delete", func(tt *testing.T) {
................................................................................
				tt.Errorf("exp=%v, but got=%v", tc.exp, got)
			}
		})
	}
}

const (
	creatorZid = id.Zid(1013)
	readerZid  = id.Zid(1013)
	writerZid  = id.Zid(1015)
	ownerZid   = id.Zid(1017)
	owner2Zid  = id.Zid(1019)
	zettelZid  = id.Zid(1021)
	visZid     = id.Zid(1023)
	userZid    = id.Zid(1025)
)

func newAnon() *meta.Meta { return nil }
func newCreator() *meta.Meta {
	user := meta.New(creatorZid)
	user.Set(meta.KeyTitle, "Creator")
	user.Set(meta.KeyRole, meta.ValueRoleUser)
	user.Set(meta.KeyUserRole, meta.ValueUserRoleCreator)
	return user
}
func newReader() *meta.Meta {
	user := meta.New(readerZid)
	user.Set(meta.KeyTitle, "Reader")
	user.Set(meta.KeyRole, meta.ValueRoleUser)
	user.Set(meta.KeyUserRole, meta.ValueUserRoleReader)
	return user
}
................................................................................
	return m
}
func newPublicZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Public Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityPublic)
	return m
}
func newCreatorZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Creator Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityCreator)
	return m
}
func newLoginZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Login Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityLogin)
	return m
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package box provides a generic interface to zettel boxes.
package box

import (
	"context"
	"errors"
	"fmt"
	"io"
	"time"

	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/search"
)

// BaseBox is implemented by all Zettel boxes.
type BaseBox interface {
	// Location returns some information where the box is located.
	// Format is dependent of the box.
	Location() string

	// CanCreateZettel returns true, if box could possibly create a new zettel.
	CanCreateZettel(ctx context.Context) bool

	// CreateZettel creates a new zettel.
	// Returns the new zettel id (and an error indication).
	CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error)

	// GetZettel retrieves a specific zettel.
	GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error)

	// GetMeta retrieves just the meta data of a specific zettel.
	GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error)

	// FetchZids returns the set of all zettel identifer managed by the box.
	FetchZids(ctx context.Context) (id.Set, error)

	// CanUpdateZettel returns true, if box could possibly update the given zettel.
	CanUpdateZettel(ctx context.Context, zettel domain.Zettel) bool

	// UpdateZettel updates an existing zettel.
	UpdateZettel(ctx context.Context, zettel domain.Zettel) error

	// AllowRenameZettel returns true, if box will not disallow renaming the zettel.
	AllowRenameZettel(ctx context.Context, zid id.Zid) bool

	// RenameZettel changes the current Zid to a new Zid.
	RenameZettel(ctx context.Context, curZid, newZid id.Zid) error

	// CanDeleteZettel returns true, if box could possibly delete the given zettel.
	CanDeleteZettel(ctx context.Context, zid id.Zid) bool

	// DeleteZettel removes the zettel from the box.
	DeleteZettel(ctx context.Context, zid id.Zid) error
}

// ManagedBox is the interface of managed boxes.
type ManagedBox interface {
	BaseBox

	// SelectMeta returns all zettel meta data that match the selection criteria.
	SelectMeta(ctx context.Context, match search.MetaMatchFunc) ([]*meta.Meta, error)

	// ReadStats populates st with box statistics
	ReadStats(st *ManagedBoxStats)
}

// ManagedBoxStats records statistics about the box.
type ManagedBoxStats struct {
	// ReadOnly indicates that the content of a box cannot change.
	ReadOnly bool

	// Zettel is the number of zettel managed by the box.
	Zettel int
}

// StartStopper performs simple lifecycle management.
type StartStopper interface {
	// Start the box. Now all other functions of the box are allowed.
	// Starting an already started box is not allowed.
	Start(ctx context.Context) error

	// Stop the started box. Now only the Start() function is allowed.
	Stop(ctx context.Context) error
}

// Box is to be used outside the box package and its descendants.
type Box interface {
	BaseBox

	// SelectMeta returns a list of metadata that comply to the given selection criteria.
	SelectMeta(ctx context.Context, s *search.Search) ([]*meta.Meta, error)

	// GetAllZettel retrieves a specific zettel from all managed boxes.
	GetAllZettel(ctx context.Context, zid id.Zid) ([]domain.Zettel, error)

	// GetAllMeta retrieves the meta data of a specific zettel from all managed boxes.
	GetAllMeta(ctx context.Context, zid id.Zid) ([]*meta.Meta, error)
}

// Stats record stattistics about a box.
type Stats struct {
	// ReadOnly indicates that boxes cannot be modified.
	ReadOnly bool

	// NumManagedBoxes is the number of boxes managed.
	NumManagedBoxes int

	// Zettel is the number of zettel managed by the box, including
	// duplicates across managed boxes.
	ZettelTotal int

	// LastReload stores the timestamp when a full re-index was done.
	LastReload time.Time

	// DurLastReload is the duration of the last full re-index run.
	DurLastReload time.Duration

	// IndexesSinceReload counts indexing a zettel since the full re-index.
	IndexesSinceReload uint64

	// ZettelIndexed is the number of zettel managed by the indexer.
	ZettelIndexed int

	// IndexUpdates count the number of metadata updates.
	IndexUpdates uint64

	// IndexedWords count the different words indexed.
	IndexedWords uint64

	// IndexedUrls count the different URLs indexed.
	IndexedUrls uint64
}

// Manager is a box-managing box.
type Manager interface {
	Box
	StartStopper
	Subject

	// ReadStats populates st with box statistics
	ReadStats(st *Stats)

	// Dump internal data to a Writer.
	Dump(w io.Writer)
}

// UpdateReason gives an indication, why the ObserverFunc was called.
type UpdateReason uint8

// Values for Reason
const (
	_        UpdateReason = iota
	OnReload              // Box was reloaded
	OnUpdate              // A zettel was created or changed
	OnDelete              // A zettel was removed
)

// UpdateInfo contains all the data about a changed zettel.
type UpdateInfo struct {
	Box    Box
	Reason UpdateReason
	Zid    id.Zid
}

// UpdateFunc is a function to be called when a change is detected.
type UpdateFunc func(UpdateInfo)

// Subject is a box that notifies observers about changes.
type Subject interface {
	// RegisterObserver registers an observer that will be notified
	// if one or all zettel are found to be changed.
	RegisterObserver(UpdateFunc)
}

// Enricher is used to update metadata by adding new properties.
type Enricher interface {
	// Enrich computes additional properties and updates the given metadata.
	// It is typically called by zettel reading methods.
	Enrich(ctx context.Context, m *meta.Meta, boxNumber int)
}

// NoEnrichContext will signal an enricher that nothing has to be done.
// This is useful for an Indexer, but also for some box.Box calls, when
// just the plain metadata is needed.
func NoEnrichContext(ctx context.Context) context.Context {
	return context.WithValue(ctx, ctxNoEnrichKey, &ctxNoEnrichKey)
}

type ctxNoEnrichType struct{}

var ctxNoEnrichKey ctxNoEnrichType

// DoNotEnrich determines if the context is marked to not enrich metadata.
func DoNotEnrich(ctx context.Context) bool {
	_, ok := ctx.Value(ctxNoEnrichKey).(*ctxNoEnrichType)
	return ok
}

// ErrNotAllowed is returned if the caller is not allowed to perform the operation.
type ErrNotAllowed struct {
	Op   string
	User *meta.Meta
	Zid  id.Zid
}

// NewErrNotAllowed creates an new authorization error.
func NewErrNotAllowed(op string, user *meta.Meta, zid id.Zid) error {
	return &ErrNotAllowed{
		Op:   op,
		User: user,
		Zid:  zid,
	}
}

func (err *ErrNotAllowed) Error() string {
	if err.User == nil {
		if err.Zid.IsValid() {
			return fmt.Sprintf(
				"operation %q on zettel %v not allowed for not authorized user",
				err.Op,
				err.Zid.String())
		}
		return fmt.Sprintf("operation %q not allowed for not authorized user", err.Op)
	}
	if err.Zid.IsValid() {
		return fmt.Sprintf(
			"operation %q on zettel %v not allowed for user %v/%v",
			err.Op,
			err.Zid.String(),
			err.User.GetDefault(meta.KeyUserID, "?"),
			err.User.Zid.String())
	}
	return fmt.Sprintf(
		"operation %q not allowed for user %v/%v",
		err.Op,
		err.User.GetDefault(meta.KeyUserID, "?"),
		err.User.Zid.String())
}

// Is return true, if the error is of type ErrNotAllowed.
func (err *ErrNotAllowed) Is(target error) bool { return true }

// ErrStarted is returned when trying to start an already started box.
var ErrStarted = errors.New("box is already started")

// ErrStopped is returned if calling methods on a box that was not started.
var ErrStopped = errors.New("box is stopped")

// ErrReadOnly is returned if there is an attepmt to write to a read-only box.
var ErrReadOnly = errors.New("read-only box")

// ErrNotFound is returned if a zettel was not found in the box.
var ErrNotFound = errors.New("zettel not found")

// ErrConflict is returned if a box operation detected a conflict..
// One example: if calculating a new zettel identifier takes too long.
var ErrConflict = errors.New("conflict")

// ErrInvalidID is returned if the zettel id is not appropriate for the box operation.
type ErrInvalidID struct{ Zid id.Zid }

func (err *ErrInvalidID) Error() string { return "invalid Zettel id: " + err.Zid.String() }

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package compbox provides zettel that have computed content.
package compbox

import (
	"context"
	"net/url"

	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager"
	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/search"
)

func init() {
	manager.Register(
		" comp",
		func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
			return getCompBox(cdata.Number, cdata.Enricher), nil
		})
}

type compBox struct {
	number   int
	enricher box.Enricher
}

var myConfig *meta.Meta
var myZettel = map[id.Zid]struct {
	meta    func(id.Zid) *meta.Meta
	content func(*meta.Meta) string
}{
	id.VersionZid:              {genVersionBuildM, genVersionBuildC},
	id.HostZid:                 {genVersionHostM, genVersionHostC},
	id.OperatingSystemZid:      {genVersionOSM, genVersionOSC},
	id.BoxManagerZid:           {genManagerM, genManagerC},
	id.MetadataKeyZid:          {genKeysM, genKeysC},
	id.StartupConfigurationZid: {genConfigZettelM, genConfigZettelC},
}

// Get returns the one program box.
func getCompBox(boxNumber int, mf box.Enricher) box.ManagedBox {
	return &compBox{number: boxNumber, enricher: mf}
}

// Setup remembers important values.
func Setup(cfg *meta.Meta) { myConfig = cfg.Clone() }

func (pp *compBox) Location() string { return "" }

func (pp *compBox) CanCreateZettel(ctx context.Context) bool { return false }

func (pp *compBox) CreateZettel(
	ctx context.Context, zettel domain.Zettel) (id.Zid, error) {
	return id.Invalid, box.ErrReadOnly
}

func (pp *compBox) GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
	if gen, ok := myZettel[zid]; ok && gen.meta != nil {
		if m := gen.meta(zid); m != nil {
			updateMeta(m)
			if genContent := gen.content; genContent != nil {
				return domain.Zettel{
					Meta:    m,
					Content: domain.NewContent(genContent(m)),
				}, nil
			}
			return domain.Zettel{Meta: m}, nil
		}
	}
	return domain.Zettel{}, box.ErrNotFound
}

func (pp *compBox) GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
	if gen, ok := myZettel[zid]; ok {
		if genMeta := gen.meta; genMeta != nil {
			if m := genMeta(zid); m != nil {
				updateMeta(m)
				return m, nil
			}
		}
	}
	return nil, box.ErrNotFound
}

func (pp *compBox) FetchZids(ctx context.Context) (id.Set, error) {
	result := id.NewSetCap(len(myZettel))
	for zid, gen := range myZettel {
		if genMeta := gen.meta; genMeta != nil {
			if genMeta(zid) != nil {
				result[zid] = true
			}
		}
	}
	return result, nil
}

func (pp *compBox) SelectMeta(ctx context.Context, match search.MetaMatchFunc) (res []*meta.Meta, err error) {
	for zid, gen := range myZettel {
		if genMeta := gen.meta; genMeta != nil {
			if m := genMeta(zid); m != nil {
				updateMeta(m)
				pp.enricher.Enrich(ctx, m, pp.number)
				if match(m) {
					res = append(res, m)
				}
			}
		}
	}
	return res, nil
}

func (pp *compBox) CanUpdateZettel(ctx context.Context, zettel domain.Zettel) bool {
	return false
}

func (pp *compBox) UpdateZettel(ctx context.Context, zettel domain.Zettel) error {
	return box.ErrReadOnly
}

func (pp *compBox) AllowRenameZettel(ctx context.Context, zid id.Zid) bool {
	_, ok := myZettel[zid]
	return !ok
}

func (pp *compBox) RenameZettel(ctx context.Context, curZid, newZid id.Zid) error {
	if _, ok := myZettel[curZid]; ok {
		return box.ErrReadOnly
	}
	return box.ErrNotFound
}

func (pp *compBox) CanDeleteZettel(ctx context.Context, zid id.Zid) bool { return false }

func (pp *compBox) DeleteZettel(ctx context.Context, zid id.Zid) error {
	if _, ok := myZettel[zid]; ok {
		return box.ErrReadOnly
	}
	return box.ErrNotFound
}

func (pp *compBox) ReadStats(st *box.ManagedBoxStats) {
	st.ReadOnly = true
	st.Zettel = len(myZettel)
}

func updateMeta(m *meta.Meta) {
	m.Set(meta.KeyNoIndex, meta.ValueTrue)
	m.Set(meta.KeySyntax, meta.ValueSyntaxZmk)
	m.Set(meta.KeyRole, meta.ValueRoleConfiguration)
	m.Set(meta.KeyLang, meta.ValueLangEN)
	m.Set(meta.KeyReadOnly, meta.ValueTrue)
	if _, ok := m.Get(meta.KeyVisibility); !ok {
		m.Set(meta.KeyVisibility, meta.ValueVisibilityExpert)
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package compbox provides zettel that have computed content.
package compbox

import (
	"strings"

	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
)

func genConfigZettelM(zid id.Zid) *meta.Meta {
	if myConfig == nil {
		return nil
	}
	m := meta.New(zid)
	m.Set(meta.KeyTitle, "Zettelstore Startup Configuration")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityExpert)
	return m
}

func genConfigZettelC(m *meta.Meta) string {
	var sb strings.Builder
	for i, p := range myConfig.Pairs(false) {
		if i > 0 {
			sb.WriteByte('\n')
		}
		sb.WriteString("; ''")
		sb.WriteString(p.Key)
		sb.WriteString("''")
		if p.Value != "" {
			sb.WriteString("\n: ``")
			for _, r := range p.Value {
				if r == '`' {
					sb.WriteByte('\\')
				}
				sb.WriteRune(r)
			}
			sb.WriteString("``")
		}
	}
	return sb.String()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package compbox provides zettel that have computed content.
package compbox

import (
	"fmt"
	"strings"

	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
)

func genKeysM(zid id.Zid) *meta.Meta {
	m := meta.New(zid)
	m.Set(meta.KeyTitle, "Zettelstore Supported Metadata Keys")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityLogin)
	return m
}

func genKeysC(*meta.Meta) string {
	keys := meta.GetSortedKeyDescriptions()
	var sb strings.Builder
	sb.WriteString("|=Name<|=Type<|=Computed?:|=Property?:\n")
	for _, kd := range keys {
		fmt.Fprintf(&sb,
			"|%v|%v|%v|%v\n", kd.Name, kd.Type.Name, kd.IsComputed(), kd.IsProperty())
	}
	return sb.String()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package compbox provides zettel that have computed content.
package compbox

import (
	"fmt"
	"strings"

	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/kernel"
)

func genManagerM(zid id.Zid) *meta.Meta {
	m := meta.New(zid)
	m.Set(meta.KeyTitle, "Zettelstore Box Manager")
	return m
}

func genManagerC(*meta.Meta) string {
	kvl := kernel.Main.GetServiceStatistics(kernel.BoxService)
	if len(kvl) == 0 {
		return "No statistics available"
	}
	var sb strings.Builder
	sb.WriteString("|=Name|=Value>\n")
	for _, kv := range kvl {
		fmt.Fprintf(&sb, "| %v | %v\n", kv.Key, kv.Value)
	}
	return sb.String()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package compbox provides zettel that have computed content.
package compbox

import (
	"fmt"

	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/kernel"
)

func getVersionMeta(zid id.Zid, title string) *meta.Meta {
	m := meta.New(zid)
	m.Set(meta.KeyTitle, title)
	m.Set(meta.KeyVisibility, meta.ValueVisibilityExpert)
	return m
}

func genVersionBuildM(zid id.Zid) *meta.Meta {
	m := getVersionMeta(zid, "Zettelstore Version")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityPublic)
	return m
}
func genVersionBuildC(*meta.Meta) string {
	return kernel.Main.GetConfig(kernel.CoreService, kernel.CoreVersion).(string)
}

func genVersionHostM(zid id.Zid) *meta.Meta {
	return getVersionMeta(zid, "Zettelstore Host")
}
func genVersionHostC(*meta.Meta) string {
	return kernel.Main.GetConfig(kernel.CoreService, kernel.CoreHostname).(string)
}

func genVersionOSM(zid id.Zid) *meta.Meta {
	return getVersionMeta(zid, "Zettelstore Operating System")
}
func genVersionOSC(*meta.Meta) string {
	return fmt.Sprintf(
		"%v/%v",
		kernel.Main.GetConfig(kernel.CoreService, kernel.CoreGoOS).(string),
		kernel.Main.GetConfig(kernel.CoreService, kernel.CoreGoArch).(string),
	)
}

*,*::before,*::after {
    box-sizing: border-box;
  }
  html {
    font-size: 1rem;
    font-family: serif;
    scroll-behavior: smooth;
    height: 100%;
  }
  body {
    margin: 0;
    min-height: 100vh;
    text-rendering: optimizeSpeed;
    line-height: 1.4;
    overflow-x: hidden;
    background-color: #f8f8f8 ;
    height: 100%;
  }
  nav.zs-menu {
    background-color: hsl(210, 28%, 90%);
    overflow: auto;
    white-space: nowrap;
    font-family: sans-serif;
    padding-left: .5rem;
  }
  nav.zs-menu > a {
    float:left;
    display: block;
    text-align: center;
    padding:.41rem .5rem;
    text-decoration: none;
    color:black;
  }
  nav.zs-menu > a:hover, .zs-dropdown:hover button {
    background-color: hsl(210, 28%, 80%);
  }
  nav.zs-menu form {
    float: right;
  }
  nav.zs-menu form input[type=text] {
    padding: .12rem;
    border: none;
    margin-top: .25rem;
    margin-right: .5rem;
  }
  .zs-dropdown {
    float: left;
    overflow: hidden;
  }
  .zs-dropdown > button {
    font-size: 16px;
    border: none;
    outline: none;
    color: black;
    padding:.41rem .5rem;
    background-color: inherit;
    font-family: inherit;
    margin: 0;
  }
  .zs-dropdown-content {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    z-index: 1;
  }
  .zs-dropdown-content > a {
    float: none;
    color: black;
    padding:.41rem .5rem;
    text-decoration: none;
    display: block;
    text-align: left;
  }
  .zs-dropdown-content > a:hover {
    background-color: hsl(210, 28%, 75%);
  }
  .zs-dropdown:hover > .zs-dropdown-content {
    display: block;
  }
  main {
    padding: 0 1rem;
  }
  article > * + * {
    margin-top: .5rem;
  }
  article header {
    padding: 0;
    margin: 0;
  }
  h1,h2,h3,h4,h5,h6 { font-family:sans-serif; font-weight:normal }
  h1 { font-size:1.5rem;  margin:.65rem 0 }
  h2 { font-size:1.25rem; margin:.70rem 0 }
  h3 { font-size:1.15rem; margin:.75rem 0 }
  h4 { font-size:1.05rem; margin:.8rem 0; font-weight: bold }
  h5 { font-size:1.05rem; margin:.8rem 0 }
  h6 { font-size:1.05rem; margin:.8rem 0; font-weight: lighter }
  p {
    margin: .5rem 0 0 0;
  }
  ol,ul {
    padding-left: 1.1rem;
  }
  li,figure,figcaption,dl {
    margin: 0;
  }
  dt {
    margin: .5rem 0 0 0;
  }
  dt+dd {
    margin-top: 0;
  }
  dd {
    margin: .5rem 0 0 2rem;
  }
  dd > p:first-child {
    margin: 0 0 0 0;
  }
  blockquote {
    border-left: 0.5rem solid lightgray;
    padding-left: 1rem;
    margin-left: 1rem;
    margin-right: 2rem;
    font-style: italic;
  }
  blockquote p {
    margin-bottom: .5rem;
  }
  blockquote cite {
    font-style: normal;
  }
  table {
    border-collapse: collapse;
    border-spacing: 0;
    max-width: 100%;
  }
  th,td {
    text-align: left;
    padding: .25rem .5rem;
  }
  td { border-bottom: 1px solid hsl(0, 0%, 85%); }
  thead th { border-bottom: 2px solid hsl(0, 0%, 70%); }
  tfoot th { border-top: 2px solid hsl(0, 0%, 70%); }
  main form {
    padding: 0 .5em;
    margin: .5em 0 0 0;
  }
  main form:after {
    content: ".";
    display: block;
    height: 0;
    clear: both;
    visibility: hidden;
  }
  main form div {
    margin: .5em 0 0 0
  }
  input {
    font-family: monospace;
  }
  input[type="submit"],button,select {
    font: inherit;
  }
  label { font-family: sans-serif; font-size:.9rem }
  label::after { content:":" }
  textarea {
    font-family: monospace;
    resize: vertical;
    width: 100%;
  }
  .zs-input {
    padding: .5em;
    display:block;
    border:none;
    border-bottom:1px solid #ccc;
    width:100%;
  }
  .zs-button {
    float:right;
    margin: .5em 0 .5em 1em;
  }
  a:not([class]) {
    text-decoration-skip-ink: auto;
  }
  .zs-broken {
    text-decoration: line-through;
  }
  img {
    max-width: 100%;
  }
  .zs-endnotes {
    padding-top: .5rem;
    border-top: 1px solid;
  }
  code,pre,kbd {
    font-family: monospace;
    font-size: 85%;
  }
  code {
    padding: .1rem .2rem;
    background: #f0f0f0;
    border: 1px solid #ccc;
    border-radius: .25rem;
  }
  pre {
    padding: .5rem .7rem;
    max-width: 100%;
    overflow: auto;
    border: 1px solid #ccc;
    border-radius: .5rem;
    background: #f0f0f0;
  }
  pre code {
    font-size: 95%;
    position: relative;
    padding: 0;
    border: none;
  }
  div.zs-indication {
    padding: .5rem .7rem;
    max-width: 100%;
    border-radius: .5rem;
    border: 1px solid black;
  }
  div.zs-indication p:first-child {
    margin-top: 0;
  }
  span.zs-indication {
    border: 1px solid black;
    border-radius: .25rem;
    padding: .1rem .2rem;
    font-size: 95%;
  }
  .zs-example { border-style: dotted !important }
  .zs-error {
    background-color: lightpink;
    border-style: none !important;
    font-weight: bold;
  }
  kbd {
    background: hsl(210, 5%, 100%);
    border: 1px solid hsl(210, 5%, 70%);
    border-radius: .25rem;
    padding: .1rem .2rem;
    font-size: 75%;
  }
  .zs-meta {
    font-size:.75rem;
    color:#444;
    margin-bottom:1rem;
  }
  .zs-meta a {
    color:#444;
  }
  h1+.zs-meta {
    margin-top:-1rem;
  }
  details > summary {
    width: 100%;
    background-color: #eee;
    font-family:sans-serif;
  }
  details > ul {
    margin-top:0;
    padding-left:2rem;
    background-color: #eee;
  }
  footer {
    padding: 0 1rem;
  }
  @media (prefers-reduced-motion: reduce) {
    * {
      animation-duration: 0.01ms !important;
      animation-iteration-count: 1 !important;
      transition-duration: 0.01ms !important;
      scroll-behavior: auto !important;
    }
  }

<!DOCTYPE html>
<html{{#Lang}} lang="{{Lang}}"{{/Lang}}>
<head>
<meta charset="utf-8">
<meta name="referrer" content="no-referrer">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="generator" content="Zettelstore">
<meta name="format-detection" content="telephone=no">
{{{MetaHeader}}}
<link rel="stylesheet" href="{{{CSSBaseURL}}}">
<link rel="stylesheet" href="{{{CSSUserURL}}}">
<title>{{Title}}</title>
</head>
<body>
<nav class="zs-menu">
<a href="{{{HomeURL}}}">Home</a>
{{#WithUser}}
<div class="zs-dropdown">
<button>User</button>
<nav class="zs-dropdown-content">
{{#WithAuth}}
{{#UserIsValid}}
<a href="{{{UserZettelURL}}}">{{UserIdent}}</a>
{{/UserIsValid}}
{{^UserIsValid}}
<a href="{{{LoginURL}}}">Login</a>
{{/UserIsValid}}
{{#UserIsValid}}
<a href="{{{UserLogoutURL}}}">Logout</a>
{{/UserIsValid}}
{{/WithAuth}}
</nav>
</div>
{{/WithUser}}
<div class="zs-dropdown">
<button>Lists</button>
<nav class="zs-dropdown-content">
<a href="{{{ListZettelURL}}}">List Zettel</a>
<a href="{{{ListRolesURL}}}">List Roles</a>
<a href="{{{ListTagsURL}}}">List Tags</a>
</nav>
</div>
{{#HasNewZettelLinks}}
<div class="zs-dropdown">
<button>New</button>
<nav class="zs-dropdown-content">
{{#NewZettelLinks}}
<a href="{{{URL}}}">{{Text}}</a>
{{/NewZettelLinks}}
</nav>
</div>
{{/HasNewZettelLinks}}
<form action="{{{SearchURL}}}">
<input type="text" placeholder="Search.." name="s">
</form>
</nav>
<main class="content">
{{{Content}}}
</main>
{{#FooterHTML}}
<footer>
{{{FooterHTML}}}
</footer>
{{/FooterHTML}}
</body>
</html>

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package constbox puts zettel inside the executable.
package constbox

import (
	"context"
	_ "embed" // Allow to embed file content
	"net/url"

	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager"
	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/search"
)

func init() {
	manager.Register(
		" const",
		func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
			return &constBox{
				number:   cdata.Number,
				zettel:   constZettelMap,
				enricher: cdata.Enricher,
			}, nil
		})
}

type constHeader map[string]string

func makeMeta(zid id.Zid, h constHeader) *meta.Meta {
	m := meta.New(zid)
	for k, v := range h {
		m.Set(k, v)
	}
	return m
}

type constZettel struct {
	header  constHeader
	content domain.Content
}

type constBox struct {
	number   int
	zettel   map[id.Zid]constZettel
	enricher box.Enricher
}

func (cp *constBox) Location() string {
	return "const:"
}

func (cp *constBox) CanCreateZettel(ctx context.Context) bool { return false }

func (cp *constBox) CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error) {
	return id.Invalid, box.ErrReadOnly
}

func (cp *constBox) GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
	if z, ok := cp.zettel[zid]; ok {
		return domain.Zettel{Meta: makeMeta(zid, z.header), Content: z.content}, nil
	}
	return domain.Zettel{}, box.ErrNotFound
}

func (cp *constBox) GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
	if z, ok := cp.zettel[zid]; ok {
		return makeMeta(zid, z.header), nil
	}
	return nil, box.ErrNotFound
}

func (cp *constBox) FetchZids(ctx context.Context) (id.Set, error) {
	result := id.NewSetCap(len(cp.zettel))
	for zid := range cp.zettel {
		result[zid] = true
	}
	return result, nil
}

func (cp *constBox) SelectMeta(ctx context.Context, match search.MetaMatchFunc) (res []*meta.Meta, err error) {
	for zid, zettel := range cp.zettel {
		m := makeMeta(zid, zettel.header)
		cp.enricher.Enrich(ctx, m, cp.number)
		if match(m) {
			res = append(res, m)
		}
	}
	return res, nil
}

func (cp *constBox) CanUpdateZettel(ctx context.Context, zettel domain.Zettel) bool {
	return false
}

func (cp *constBox) UpdateZettel(ctx context.Context, zettel domain.Zettel) error {
	return box.ErrReadOnly
}

func (cp *constBox) AllowRenameZettel(ctx context.Context, zid id.Zid) bool {
	_, ok := cp.zettel[zid]
	return !ok
}

func (cp *constBox) RenameZettel(ctx context.Context, curZid, newZid id.Zid) error {
	if _, ok := cp.zettel[curZid]; ok {
		return box.ErrReadOnly
	}
	return box.ErrNotFound
}
func (cp *constBox) CanDeleteZettel(ctx context.Context, zid id.Zid) bool { return false }

func (cp *constBox) DeleteZettel(ctx context.Context, zid id.Zid) error {
	if _, ok := cp.zettel[zid]; ok {
		return box.ErrReadOnly
	}
	return box.ErrNotFound
}

func (cp *constBox) ReadStats(st *box.ManagedBoxStats) {
	st.ReadOnly = true
	st.Zettel = len(cp.zettel)
}

const syntaxTemplate = "mustache"

var constZettelMap = map[id.Zid]constZettel{
	id.ConfigurationZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Runtime Configuration",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxNone,
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityOwner,
		},
		domain.NewContent("")},
	id.LicenseZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore License",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxText,
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyReadOnly:   meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityPublic,
		},
		domain.NewContent(contentLicense)},
	id.AuthorsZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Contributors",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxZmk,
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyReadOnly:   meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityPublic,
		},
		domain.NewContent(contentContributors)},
	id.DependenciesZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Dependencies",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxZmk,
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyReadOnly:   meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityPublic,
		},
		domain.NewContent(contentDependencies)},
	id.BaseTemplateZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Base HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     syntaxTemplate,
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		domain.NewContent(contentBaseMustache)},
	id.LoginTemplateZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Login Form HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     syntaxTemplate,
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		domain.NewContent(contentLoginMustache)},
	id.ZettelTemplateZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Zettel HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     syntaxTemplate,
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		domain.NewContent(contentZettelMustache)},
	id.InfoTemplateZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Info HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     syntaxTemplate,
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		domain.NewContent(contentInfoMustache)},
	id.ContextTemplateZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Context HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     syntaxTemplate,
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		domain.NewContent(contentContextMustache)},
	id.FormTemplateZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Form HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     syntaxTemplate,
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		domain.NewContent(contentFormMustache)},
	id.RenameTemplateZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Rename Form HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     syntaxTemplate,
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		domain.NewContent(contentRenameMustache)},
	id.DeleteTemplateZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Delete HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     syntaxTemplate,
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		domain.NewContent(contentDeleteMustache)},
	id.ListTemplateZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore List Zettel HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     syntaxTemplate,
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		domain.NewContent(contentListZettelMustache)},
	id.RolesTemplateZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore List Roles HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     syntaxTemplate,
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		domain.NewContent(contentListRolesMustache)},
	id.TagsTemplateZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore List Tags HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     syntaxTemplate,
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		domain.NewContent(contentListTagsMustache)},
	id.ErrorTemplateZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Error HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     syntaxTemplate,
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		domain.NewContent(contentErrorMustache)},
	id.BaseCSSZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Base CSS",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     "css",
			meta.KeyNoIndex:    meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityPublic,
		},
		domain.NewContent(contentBaseCSS)},
	id.UserCSSZid: {
		constHeader{
			meta.KeyTitle:      "Zettelstore User CSS",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     "css",
			meta.KeyVisibility: meta.ValueVisibilityPublic,
		},
		domain.NewContent("/* User-defined CSS */")},
	id.EmojiZid: {
		constHeader{
			meta.KeyTitle:      "Generic Emoji",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxGif,
			meta.KeyReadOnly:   meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityPublic,
		},
		domain.NewContent(contentEmoji)},
	id.TOCNewTemplateZid: {
		constHeader{
			meta.KeyTitle:      "New Menu",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxZmk,
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyVisibility: meta.ValueVisibilityCreator,
		},
		domain.NewContent(contentNewTOCZettel)},
	id.TemplateNewZettelZid: {
		constHeader{
			meta.KeyTitle:      "New Zettel",
			meta.KeyRole:       meta.ValueRoleZettel,
			meta.KeySyntax:     meta.ValueSyntaxZmk,
			meta.KeyVisibility: meta.ValueVisibilityCreator,
		},
		domain.NewContent("")},
	id.TemplateNewUserZid: {
		constHeader{
			meta.KeyTitle:                       "New User",
			meta.KeyRole:                        meta.ValueRoleUser,
			meta.KeySyntax:                      meta.ValueSyntaxNone,
			meta.NewPrefix + meta.KeyCredential: "",
			meta.NewPrefix + meta.KeyUserID:     "",
			meta.NewPrefix + meta.KeyUserRole:   meta.ValueUserRoleReader,
			meta.KeyVisibility:                  meta.ValueVisibilityOwner,
		},
		domain.NewContent("")},
	id.DefaultHomeZid: {
		constHeader{
			meta.KeyTitle:  "Home",
			meta.KeyRole:   meta.ValueRoleZettel,
			meta.KeySyntax: meta.ValueSyntaxZmk,
			meta.KeyLang:   meta.ValueLangEN,
		},
		domain.NewContent(contentHomeZettel)},
}

//go:embed license.txt
var contentLicense string

//go:embed contributors.zettel
var contentContributors string

//go:embed dependencies.zettel
var contentDependencies string

//go:embed base.mustache
var contentBaseMustache string

//go:embed login.mustache
var contentLoginMustache string

//go:embed zettel.mustache
var contentZettelMustache string

//go:embed info.mustache
var contentInfoMustache string

//go:embed context.mustache
var contentContextMustache string

//go:embed form.mustache
var contentFormMustache string

//go:embed rename.mustache
var contentRenameMustache string

//go:embed delete.mustache
var contentDeleteMustache string

//go:embed listzettel.mustache
var contentListZettelMustache string

//go:embed listroles.mustache
var contentListRolesMustache string

//go:embed listtags.mustache
var contentListTagsMustache string

//go:embed error.mustache
var contentErrorMustache string

//go:embed base.css
var contentBaseCSS string

//go:embed emoji_spin.gif
var contentEmoji string

//go:embed newtoc.zettel
var contentNewTOCZettel string

//go:embed home.zettel
var contentHomeZettel string

<nav>
<header>
<h1>{{Title}}</h1>
<div class="zs-meta">
<a href="{{{InfoURL}}}">Info</a>
&#183; <a href="?dir=backward">Backward</a>
&#183; <a href="?dir=both">Both</a>
&#183; <a href="?dir=forward">Forward</a>
&#183; Depth:{{#Depths}}&#x2000;<a href="{{{URL}}}">{{{Text}}}</a>{{/Depths}}
</div>
</header>
<p><a href="{{{Start.URL}}}">{{{Start.Text}}}</a></p>
<ul>
{{#Metas}}<li><a href="{{{URL}}}">{{{Text}}}</a></li>
{{/Metas}}</ul>
</nav>

Zettelstore is a software for humans made from humans.

=== Licensor(s)
* Detlef Stern [[mailto:ds@zettelstore.de]]
** Main author
** Maintainer

=== Contributors

<article>
<header>
<h1>Delete Zettel {{Zid}}</h1>
</header>
<p>Do you really want to delete this zettel?</p>
<dl>
{{#MetaPairs}}
<dt>{{Key}}:</dt><dd>{{Value}}</dd>
{{/MetaPairs}}
</dl>
<form method="POST">
<input class="zs-button" type="submit" value="Delete">
</form>
</article>
{{end}}

Zettelstore is made with the help of other software and other artifacts.
Thank you very much!

This zettel lists all of them, together with their license.

=== Go runtime and associated libraries
; License
: BSD 3-Clause "New" or "Revised" License
```
Copyright (c) 2009 The Go Authors. All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

   * Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
   * Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
   * Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
```

=== Fsnotify
; URL
: [[https://fsnotify.org/]]
; License
: BSD 3-Clause "New" or "Revised" License
; Source
: [[https://github.com/fsnotify/fsnotify]]
```
Copyright (c) 2012 The Go Authors. All rights reserved.
Copyright (c) 2012-2019 fsnotify Authors. All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

   * Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
   * Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
   * Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
```

=== hoisie/mustache / cbroglie/mustache
; URL & Source
: [[https://github.com/hoisie/mustache]] / [[https://github.com/cbroglie/mustache]]
; License
: MIT License
; Remarks
: cbroglie/mustache is a fork from hoisie/mustache (starting with commit [f9b4cbf]).
  cbroglie/mustache does not claim a copyright and includes just the license file from hoisie/mustache.
  cbroglie/mustache obviously continues with the original license.

```
Copyright (c) 2009 Michael Hoisie

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
```

===  pascaldekloe/jwt
; URL & Source
: [[https://github.com/pascaldekloe/jwt]]
; License
: [[CC0 1.0 Universal|https://creativecommons.org/publicdomain/zero/1.0/legalcode]]
```
To the extent possible under law, Pascal S. de Kloe has waived all
copyright and related or neighboring rights to JWT. This work is
published from The Netherlands.

https://creativecommons.org/publicdomain/zero/1.0/legalcode
```

=== yuin/goldmark
; URL & Source
: [[https://github.com/yuin/goldmark]]
; License
: MIT License
```
MIT License

Copyright (c) 2019 Yusuke Inuzuka

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
```

<article>
<header>
<h1>{{ErrorTitle}}</h1>
</header>
{{ErrorText}}
</article>

<article>
<header>
<h1>{{Heading}}</h1>
</header>
<form method="POST">
<div>
<label for="title">Title</label>
<input class="zs-input" type="text" id="title" name="title" placeholder="Title.." value="{{MetaTitle}}" autofocus>
</div>
<div>
<div>
<label for="role">Role</label>
<input class="zs-input" type="text" id="role" name="role" placeholder="role.." value="{{MetaRole}}">
</div>
<label for="tags">Tags</label>
<input class="zs-input" type="text" id="tags" name="tags" placeholder="#tag" value="{{MetaTags}}">
</div>
<div>
<label for="meta">Metadata</label>
<textarea class="zs-input" id="meta" name="meta" rows="4" placeholder="metakey: metavalue">
{{#MetaPairsRest}}
{{Key}}: {{Value}}
{{/MetaPairsRest}}
</textarea>
</div>
<div>
<label for="syntax">Syntax</label>
<input class="zs-input" type="text" id="syntax" name="syntax" placeholder="syntax.." value="{{MetaSyntax}}">
</div>
<div>
{{#IsTextContent}}
<label for="content">Content</label>
<textarea class="zs-input zs-content" id="meta" name="content" rows="20" placeholder="Your content..">{{Content}}</textarea>
{{/IsTextContent}}
</div>
<input class="zs-button" type="submit" value="Submit">
</form>
</article>

=== Thank you for using Zettelstore!

You will find the lastest information about Zettelstore at [[https://zettelstore.de]].
Check that website regulary for [[upgrades|https://zettelstore.de/home/doc/trunk/www/download.wiki]] to the latest version.
You should consult the [[change log|https://zettelstore.de/home/doc/trunk/www/changes.wiki]] before upgrading.
Sometimes, you have to edit some of your Zettelstore-related zettel before upgrading.
Since Zettelstore is currently in a development state, every upgrade might fix some of your problems.
To check for versions, there is a zettel with the [[current version|00000000000001]] of your Zettelstore.

If you have problems concerning Zettelstore,
do not hesitate to get in [[contact with the main developer|mailto:ds@zettelstore.de]].

=== Reporting errors
If you have encountered an error, please include the content of the following zettel in your mail (if possible):
* [[Zettelstore Version|00000000000001]]
* [[Zettelstore Operating System|00000000000003]]
* [[Zettelstore Startup Configuration|00000000000096]]
* [[Zettelstore Runtime Configuration|00000000000100]]

Additionally, you have to describe, what you have done before that error occurs
and what you have expected instead.
Please do not forget to include the error message, if there is one.

Some of above Zettelstore zettel can only be retrieved if you enabled ""expert mode"".
Otherwise, only some zettel are linked.
To enable expert mode, edit the zettel [[Zettelstore Runtime Configuration|00000000000100]]:
please set the metadata value of the key ''expert-mode'' to true.
To do you, enter the string ''expert-mode:true'' inside the edit view of the metadata.

=== Information about this zettel
This zettel is your home zettel.
It is part of the Zettelstore software itself.
Every time you click on the [[Home|//]] link in the menu bar, you will be redirected to this zettel.

You can change the content of this zettel by clicking on ""Edit"" above.
This allows you to customize your home zettel.

Alternatively, you can designate another zettel as your home zettel.
Edit the [[Zettelstore Runtime Configuration|00000000000100]] by adding the metadata key ''home-zettel''.
Its value is the identifier of the zettel that should act as the new home zettel.
You will find the identifier of each zettel between their ""Edit"" and the ""Info"" link above.
The identifier of this zettel is ''00010000000000''.
If you provide a wrong identifier, this zettel will be shown as the home zettel.
Take a look inside the manual for further details.

<article>
<header>
<h1>Information for Zettel {{Zid}}</h1>
<a href="{{{WebURL}}}">Web</a>
&#183; <a href="{{{ContextURL}}}">Context</a>
{{#CanWrite}} &#183; <a href="{{{EditURL}}}">Edit</a>{{/CanWrite}}
{{#CanFolge}} &#183; <a href="{{{FolgeURL}}}">Folge</a>{{/CanFolge}}
{{#CanCopy}} &#183; <a href="{{{CopyURL}}}">Copy</a>{{/CanCopy}}
{{#CanRename}}&#183; <a href="{{{RenameURL}}}">Rename</a>{{/CanRename}}
{{#CanDelete}}&#183; <a href="{{{DeleteURL}}}">Delete</a>{{/CanDelete}}
</header>
<h2>Interpreted Metadata</h2>
<table>{{#MetaData}}<tr><td>{{Key}}</td><td>{{{Value}}}</td></tr>{{/MetaData}}</table>
{{#HasLinks}}
<h2>References</h2>
{{#HasLocLinks}}
<h3>Local</h3>
<ul>
{{#LocLinks}}
{{#Valid}}<li><a href="{{{Zid}}}">{{Zid}}</a></li>{{/Valid}}
{{^Valid}}<li>{{Zid}}</li>{{/Valid}}
{{/LocLinks}}
</ul>
{{/HasLocLinks}}
{{#HasExtLinks}}
<h3>External</h3>
<ul>
{{#ExtLinks}}
<li><a href="{{{.}}}"{{{ExtNewWindow}}}>{{.}}</a></li>
{{/ExtLinks}}
</ul>
{{/HasExtLinks}}
{{/HasLinks}}
<h2>Parts and format</h3>
<table>
{{#Matrix}}
<tr>
{{#Elements}}{{#HasURL}}<td><a href="{{{URL}}}">{{Text}}</td>{{/HasURL}}{{^HasURL}}<th>{{Text}}</th>{{/HasURL}}
{{/Elements}}
</tr>
{{/Matrix}}
</table>
{{#HasShadowLinks}}
<h2>Shadowed Boxes</h2>
<ul>{{#ShadowLinks}}<li>{{.}}</li>{{/ShadowLinks}}</ul>
{{/HasShadowLinks}}
{{#Endnotes}}{{{Endnotes}}}{{/Endnotes}}
</article>

Copyright (c) 2020-2021 Detlef Stern

                          Licensed under the EUPL

Zettelstore is licensed under the European Union Public License, version 1.2 or
later (EUPL v. 1.2). The license is available in the official languages of the
EU. The English version is included here. Please see
https://joinup.ec.europa.eu/community/eupl/og_page/eupl for official
translations of the other languages.


-------------------------------------------------------------------------------


EUROPEAN UNION PUBLIC LICENCE v. 1.2
EUPL © the European Union 2007, 2016

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                          Licensed under the EUPL

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                                  Appendix


‘Compatible Licences’ according to Article 5 EUPL are:

— GNU General Public License (GPL) v. 2, v. 3
— GNU Affero General Public License (AGPL) v. 3
— Open Software License (OSL) v. 2.1, v. 3.0
— Eclipse Public License (EPL) v. 1.0
— CeCILL v. 2.0, v. 2.1
— Mozilla Public Licence (MPL) v. 2
— GNU Lesser General Public Licence (LGPL) v. 2.1, v. 3
— Creative Commons Attribution-ShareAlike v. 3.0 Unported (CC BY-SA 3.0) for
  works other than software
— European Union Public Licence (EUPL) v. 1.1, v. 1.2
— Québec Free and Open-Source Licence — Reciprocity (LiLiQ-R) or Strong
  Reciprocity (LiLiQ-R+)

The European Commission may update this Appendix to later versions of the above
licences without producing a new version of the EUPL, as long as they provide
the rights granted in Article 2 of this Licence and protect the covered Source
Code from exclusive appropriation.

All other changes or additions to this Appendix require the production of a new
EUPL version.

<nav>
<header>
<h1>Currently used roles</h1>
</header>
<ul>
{{#Roles}}<li><a href="{{{URL}}}">{{Text}}</a></li>
{{/Roles}}</ul>
</nav>

<nav>
<header>
<h1>Currently used tags</h1>
<div class="zs-meta">
<a href="{{{ListTagsURL}}}">All</a>{{#MinCounts}}, <a href="{{{URL}}}">{{Count}}</a>{{/MinCounts}}
</div>
</header>
{{#Tags}} <a href="{{{URL}}}" style="font-size:{{Size}}%">{{Name}}</a><sup>{{Count}}</sup>
{{/Tags}}
</nav>

<header>
<h1>{{Title}}</h1>
</header>
<ul>
{{#Metas}}<li><a href="{{{URL}}}">{{{Text}}}</a></li>
{{/Metas}}</ul>

<article>
<header>
<h1>{{Title}}</h1>
</header>
{{#Retry}}
<div class="zs-indication zs-error">Wrong user name / password. Try again.</div>
{{/Retry}}
<form method="POST" action="?_format=html">
<div>
<label for="username">User name</label>
<input class="zs-input" type="text" id="username" name="username" placeholder="Your user name.." autofocus>
</div>
<div>
<label for="password">Password</label>
<input class="zs-input" type="password" id="password" name="password" placeholder="Your password..">
</div>
<input class="zs-button" type="submit" value="Login">
</form>
</article>

This zettel lists all zettel that should act as a template for new zettel.
These zettel will be included in the ""New"" menu of the WebUI.
* [[New Zettel|00000000090001]]
* [[New User|00000000090002]]

<article>
<header>
<h1>Rename Zettel {{.Zid}}</h1>
</header>
<p>Do you really want to rename this zettel?</p>
<form method="POST">
<div>
<label for="newid">New zettel id</label>
<input class="zs-input" type="text" id="newzid" name="newzid" placeholder="ZID.." value="{{Zid}}" autofocus>
</div>
<input type="hidden" id="curzid" name="curzid" value="{{Zid}}">
<input class="zs-button" type="submit" value="Rename">
</form>
<dl>
{{#MetaPairs}}
<dt>{{Key}}:</dt><dd>{{Value}}</dd>
{{/MetaPairs}}
</dl>
</article>

<article>
<header>
<h1>{{{HTMLTitle}}}</h1>
<div class="zs-meta">
{{#CanWrite}}<a href="{{{EditURL}}}">Edit</a> &#183;{{/CanWrite}}
{{Zid}} &#183;
<a href="{{{InfoURL}}}">Info</a> &#183;
(<a href="{{{RoleURL}}}">{{RoleText}}</a>)
{{#HasTags}}&#183; {{#Tags}} <a href="{{{URL}}}">{{Text}}</a>{{/Tags}}{{/HasTags}}
{{#CanCopy}}&#183; <a href="{{{CopyURL}}}">Copy</a>{{/CanCopy}}
{{#CanFolge}}&#183; <a href="{{{FolgeURL}}}">Folge</a>{{/CanFolge}}
{{#FolgeRefs}}<br>Folge: {{{FolgeRefs}}}{{/FolgeRefs}}
{{#PrecursorRefs}}<br>Precursor: {{{PrecursorRefs}}}{{/PrecursorRefs}}
{{#HasExtURL}}<br>URL: <a href="{{{ExtURL}}}"{{{ExtNewWindow}}}>{{ExtURL}}</a>{{/HasExtURL}}
</div>
</header>
{{{Content}}}
{{#HasBackLinks}}
<details>
<summary>Additional links to this zettel</summary>
<ul>
{{#BackLinks}}
<li><a href="{{{URL}}}">{{Text}}</a></li>
{{/BackLinks}}
</ul>
</details>
{{/HasBackLinks}}
</article>

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package dirbox provides a directory-based zettel box.
package dirbox

import (
	"context"
	"errors"
	"net/url"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"sync"
	"time"

	"zettelstore.de/z/box"
	"zettelstore.de/z/box/dirbox/directory"
	"zettelstore.de/z/box/filebox"
	"zettelstore.de/z/box/manager"
	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/search"
)

func init() {
	manager.Register("dir", func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
		path := getDirPath(u)
		if _, err := os.Stat(path); errors.Is(err, os.ErrNotExist) {
			return nil, err
		}
		dirSrvSpec, defWorker, maxWorker := getDirSrvInfo(u.Query().Get("type"))
		dp := dirBox{
			number:     cdata.Number,
			location:   u.String(),
			readonly:   getQueryBool(u, "readonly"),
			cdata:      *cdata,
			dir:        path,
			dirRescan:  time.Duration(getQueryInt(u, "rescan", 60, 3600, 30*24*60*60)) * time.Second,
			dirSrvSpec: dirSrvSpec,
			fSrvs:      uint32(getQueryInt(u, "worker", 1, defWorker, maxWorker)),
		}
		return &dp, nil
	})
}

type directoryServiceSpec int

const (
	_ directoryServiceSpec = iota
	dirSrvAny
	dirSrvSimple
	dirSrvNotify
)

func getDirPath(u *url.URL) string {
	if u.Opaque != "" {
		return filepath.Clean(u.Opaque)
	}
	return filepath.Clean(u.Path)
}

func getQueryBool(u *url.URL, key string) bool {
	_, ok := u.Query()[key]
	return ok
}

func getQueryInt(u *url.URL, key string, min, def, max int) int {
	sVal := u.Query().Get(key)
	if sVal == "" {
		return def
	}
	iVal, err := strconv.Atoi(sVal)
	if err != nil {
		return def
	}
	if iVal < min {
		return min
	}
	if iVal > max {
		return max
	}
	return iVal
}

// dirBox uses a directory to store zettel as files.
type dirBox struct {
	number     int
	location   string
	readonly   bool
	cdata      manager.ConnectData
	dir        string
	dirRescan  time.Duration
	dirSrvSpec directoryServiceSpec
	dirSrv     directory.Service
	mustNotify bool
	fSrvs      uint32
	fCmds      []chan fileCmd
	mxCmds     sync.RWMutex
}

func (dp *dirBox) Location() string {
	return dp.location
}

func (dp *dirBox) Start(ctx context.Context) error {
	dp.mxCmds.Lock()
	dp.fCmds = make([]chan fileCmd, 0, dp.fSrvs)
	for i := uint32(0); i < dp.fSrvs; i++ {
		cc := make(chan fileCmd)
		go fileService(i, cc)
		dp.fCmds = append(dp.fCmds, cc)
	}
	dp.setupDirService()
	dp.mxCmds.Unlock()
	if dp.dirSrv == nil {
		panic("No directory service")
	}
	return dp.dirSrv.Start()
}

func (dp *dirBox) Stop(ctx context.Context) error {
	dirSrv := dp.dirSrv
	dp.dirSrv = nil
	err := dirSrv.Stop()
	for _, c := range dp.fCmds {
		close(c)
	}
	return err
}

func (dp *dirBox) notifyChanged(reason box.UpdateReason, zid id.Zid) {
	if dp.mustNotify {
		if chci := dp.cdata.Notify; chci != nil {
			chci <- box.UpdateInfo{Reason: reason, Zid: zid}
		}
	}
}

func (dp *dirBox) getFileChan(zid id.Zid) chan fileCmd {
	// Based on https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function
	sum := 2166136261 ^ uint32(zid)
	sum *= 16777619
	sum ^= uint32(zid >> 32)
	sum *= 16777619

	dp.mxCmds.RLock()
	defer dp.mxCmds.RUnlock()
	return dp.fCmds[sum%dp.fSrvs]
}

func (dp *dirBox) CanCreateZettel(ctx context.Context) bool {
	return !dp.readonly
}

func (dp *dirBox) CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error) {
	if dp.readonly {
		return id.Invalid, box.ErrReadOnly
	}

	entry, err := dp.dirSrv.GetNew()
	if err != nil {
		return id.Invalid, err
	}
	meta := zettel.Meta
	meta.Zid = entry.Zid
	dp.updateEntryFromMeta(entry, meta)

	err = setZettel(dp, entry, zettel)
	if err == nil {
		dp.dirSrv.UpdateEntry(entry)
	}
	dp.notifyChanged(box.OnUpdate, meta.Zid)
	return meta.Zid, err
}

func (dp *dirBox) GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
	entry, err := dp.dirSrv.GetEntry(zid)
	if err != nil || !entry.IsValid() {
		return domain.Zettel{}, box.ErrNotFound
	}
	m, c, err := getMetaContent(dp, entry, zid)
	if err != nil {
		return domain.Zettel{}, err
	}
	dp.cleanupMeta(ctx, m)
	zettel := domain.Zettel{Meta: m, Content: domain.NewContent(c)}
	return zettel, nil
}

func (dp *dirBox) GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
	entry, err := dp.dirSrv.GetEntry(zid)
	if err != nil || !entry.IsValid() {
		return nil, box.ErrNotFound
	}
	m, err := getMeta(dp, entry, zid)
	if err != nil {
		return nil, err
	}
	dp.cleanupMeta(ctx, m)
	return m, nil
}

func (dp *dirBox) FetchZids(ctx context.Context) (id.Set, error) {
	entries, err := dp.dirSrv.GetEntries()
	if err != nil {
		return nil, err
	}
	result := id.NewSetCap(len(entries))
	for _, entry := range entries {
		result[entry.Zid] = true
	}
	return result, nil
}

func (dp *dirBox) SelectMeta(ctx context.Context, match search.MetaMatchFunc) (res []*meta.Meta, err error) {
	entries, err := dp.dirSrv.GetEntries()
	if err != nil {
		return nil, err
	}
	res = make([]*meta.Meta, 0, len(entries))
	// The following loop could be parallelized if needed for performance.
	for _, entry := range entries {
		m, err1 := getMeta(dp, entry, entry.Zid)
		err = err1
		if err != nil {
			continue
		}
		dp.cleanupMeta(ctx, m)
		dp.cdata.Enricher.Enrich(ctx, m, dp.number)

		if match(m) {
			res = append(res, m)
		}
	}
	if err != nil {
		return nil, err
	}
	return res, nil
}

func (dp *dirBox) CanUpdateZettel(ctx context.Context, zettel domain.Zettel) bool {
	return !dp.readonly
}

func (dp *dirBox) UpdateZettel(ctx context.Context, zettel domain.Zettel) error {
	if dp.readonly {
		return box.ErrReadOnly
	}

	meta := zettel.Meta
	if !meta.Zid.IsValid() {
		return &box.ErrInvalidID{Zid: meta.Zid}
	}
	entry, err := dp.dirSrv.GetEntry(meta.Zid)
	if err != nil {
		return err
	}
	if !entry.IsValid() {
		// Existing zettel, but new in this box.
		entry = &directory.Entry{Zid: meta.Zid}
		dp.updateEntryFromMeta(entry, meta)
	} else if entry.MetaSpec == directory.MetaSpecNone {
		defaultMeta := filebox.CalcDefaultMeta(entry.Zid, entry.ContentExt)
		if !meta.Equal(defaultMeta, true) {
			dp.updateEntryFromMeta(entry, meta)
			dp.dirSrv.UpdateEntry(entry)
		}
	}
	err = setZettel(dp, entry, zettel)
	if err == nil {
		dp.notifyChanged(box.OnUpdate, meta.Zid)
	}
	return err
}

func (dp *dirBox) updateEntryFromMeta(entry *directory.Entry, meta *meta.Meta) {
	entry.MetaSpec, entry.ContentExt = dp.calcSpecExt(meta)
	basePath := dp.calcBasePath(entry)
	if entry.MetaSpec == directory.MetaSpecFile {
		entry.MetaPath = basePath + ".meta"
	}
	entry.ContentPath = basePath + "." + entry.ContentExt
	entry.Duplicates = false
}

func (dp *dirBox) calcBasePath(entry *directory.Entry) string {
	p := entry.ContentPath
	if p == "" {
		return filepath.Join(dp.dir, entry.Zid.String())
	}
	// ContentPath w/o the file extension
	return p[0 : len(p)-len(filepath.Ext(p))]
}

func (dp *dirBox) calcSpecExt(m *meta.Meta) (directory.MetaSpec, string) {
	if m.YamlSep {
		return directory.MetaSpecHeader, "zettel"
	}
	syntax := m.GetDefault(meta.KeySyntax, "bin")
	switch syntax {
	case meta.ValueSyntaxNone, meta.ValueSyntaxZmk:
		return directory.MetaSpecHeader, "zettel"
	}
	for _, s := range dp.cdata.Config.GetZettelFileSyntax() {
		if s == syntax {
			return directory.MetaSpecHeader, "zettel"
		}
	}
	return directory.MetaSpecFile, syntax
}

func (dp *dirBox) AllowRenameZettel(ctx context.Context, zid id.Zid) bool {
	return !dp.readonly
}

func (dp *dirBox) RenameZettel(ctx context.Context, curZid, newZid id.Zid) error {
	if curZid == newZid {
		return nil
	}
	curEntry, err := dp.dirSrv.GetEntry(curZid)
	if err != nil || !curEntry.IsValid() {
		return box.ErrNotFound
	}
	if dp.readonly {
		return box.ErrReadOnly
	}

	// Check whether zettel with new ID already exists in this box.
	if _, err = dp.GetMeta(ctx, newZid); err == nil {
		return &box.ErrInvalidID{Zid: newZid}
	}

	oldMeta, oldContent, err := getMetaContent(dp, curEntry, curZid)
	if err != nil {
		return err
	}

	newEntry := directory.Entry{
		Zid:         newZid,
		MetaSpec:    curEntry.MetaSpec,
		MetaPath:    renamePath(curEntry.MetaPath, curZid, newZid),
		ContentPath: renamePath(curEntry.ContentPath, curZid, newZid),
		ContentExt:  curEntry.ContentExt,
	}

	if err = dp.dirSrv.RenameEntry(curEntry, &newEntry); err != nil {
		return err
	}
	oldMeta.Zid = newZid
	newZettel := domain.Zettel{Meta: oldMeta, Content: domain.NewContent(oldContent)}
	if err = setZettel(dp, &newEntry, newZettel); err != nil {
		// "Rollback" rename. No error checking...
		dp.dirSrv.RenameEntry(&newEntry, curEntry)
		return err
	}
	err = deleteZettel(dp, curEntry, curZid)
	if err == nil {
		dp.notifyChanged(box.OnDelete, curZid)
		dp.notifyChanged(box.OnUpdate, newZid)
	}
	return err
}

func (dp *dirBox) CanDeleteZettel(ctx context.Context, zid id.Zid) bool {
	if dp.readonly {
		return false
	}
	entry, err := dp.dirSrv.GetEntry(zid)
	return err == nil && entry.IsValid()
}

func (dp *dirBox) DeleteZettel(ctx context.Context, zid id.Zid) error {
	if dp.readonly {
		return box.ErrReadOnly
	}

	entry, err := dp.dirSrv.GetEntry(zid)
	if err != nil || !entry.IsValid() {
		return box.ErrNotFound
	}
	dp.dirSrv.DeleteEntry(zid)
	err = deleteZettel(dp, entry, zid)
	if err == nil {
		dp.notifyChanged(box.OnDelete, zid)
	}
	return err
}

func (dp *dirBox) ReadStats(st *box.ManagedBoxStats) {
	st.ReadOnly = dp.readonly
	st.Zettel, _ = dp.dirSrv.NumEntries()
}

func (dp *dirBox) cleanupMeta(ctx context.Context, m *meta.Meta) {
	if role, ok := m.Get(meta.KeyRole); !ok || role == "" {
		m.Set(meta.KeyRole, dp.cdata.Config.GetDefaultRole())
	}
	if syntax, ok := m.Get(meta.KeySyntax); !ok || syntax == "" {
		m.Set(meta.KeySyntax, dp.cdata.Config.GetDefaultSyntax())
	}
}

func renamePath(path string, curID, newID id.Zid) string {
	dir, file := filepath.Split(path)
	if cur := curID.String(); strings.HasPrefix(file, cur) {
		file = newID.String() + file[len(cur):]
		return filepath.Join(dir, file)
	}
	return path
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package directory manages the directory interface of a dirstore.
package directory

import "zettelstore.de/z/domain/id"

// Service is the interface of a directory service.
type Service interface {
	Start() error
	Stop() error
	NumEntries() (int, error)
	GetEntries() ([]*Entry, error)
	GetEntry(zid id.Zid) (*Entry, error)
	GetNew() (*Entry, error)
	UpdateEntry(entry *Entry) error
	RenameEntry(curEntry, newEntry *Entry) error
	DeleteEntry(zid id.Zid) error
}

// MetaSpec defines all possibilities where meta data can be stored.
type MetaSpec int

// Constants for MetaSpec
const (
	_              MetaSpec = iota
	MetaSpecNone            // no meta information
	MetaSpecFile            // meta information is in meta file
	MetaSpecHeader          // meta information is in header
)

// Entry stores everything for a directory entry.
type Entry struct {
	Zid         id.Zid
	MetaSpec    MetaSpec // location of meta information
	MetaPath    string   // file path of meta information
	ContentPath string   // file path of zettel content
	ContentExt  string   // (normalized) file extension of zettel content
	Duplicates  bool     // multiple content files
}

// IsValid checks whether the entry is valid.
func (e *Entry) IsValid() bool {
	return e != nil && e.Zid.IsValid()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package dirbox provides a directory-based zettel box.
package dirbox

import (
	"zettelstore.de/z/box/dirbox/notifydir"
	"zettelstore.de/z/box/dirbox/simpledir"
	"zettelstore.de/z/kernel"
)

func getDirSrvInfo(dirType string) (directoryServiceSpec, int, int) {
	for count := 0; count < 2; count++ {
		switch dirType {
		case kernel.BoxDirTypeNotify:
			return dirSrvNotify, 7, 1499
		case kernel.BoxDirTypeSimple:
			return dirSrvSimple, 1, 1
		default:
			dirType = kernel.Main.GetConfig(kernel.BoxService, kernel.BoxDefaultDirType).(string)
		}
	}
	panic("unable to set default dir box type: " + dirType)
}

func (dp *dirBox) setupDirService() {
	switch dp.dirSrvSpec {
	case dirSrvSimple:
		dp.dirSrv = simpledir.NewService(dp.dir)
		dp.mustNotify = true
	default:
		dp.dirSrv = notifydir.NewService(dp.dir, dp.dirRescan, dp.cdata.Notify)
		dp.mustNotify = false
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package notifydir manages the notified directory part of a dirstore.
package notifydir

import (
	"time"

	"zettelstore.de/z/box"
	"zettelstore.de/z/box/dirbox/directory"
	"zettelstore.de/z/domain/id"
)

// notifyService specifies a directory scan service.
type notifyService struct {
	dirPath    string
	rescanTime time.Duration
	done       chan struct{}
	cmds       chan dirCmd
	infos      chan<- box.UpdateInfo
}

// NewService creates a new directory service.
func NewService(directoryPath string, rescanTime time.Duration, chci chan<- box.UpdateInfo) directory.Service {
	srv := &notifyService{
		dirPath:    directoryPath,
		rescanTime: rescanTime,
		cmds:       make(chan dirCmd),
		infos:      chci,
	}
	return srv
}

// Start makes the directory service operational.
func (srv *notifyService) Start() error {
	tick := make(chan struct{})
	rawEvents := make(chan *fileEvent)
	events := make(chan *fileEvent)

	ready := make(chan int)
	go srv.directoryService(events, ready)
	go collectEvents(events, rawEvents)
	go watchDirectory(srv.dirPath, rawEvents, tick)

	if srv.done != nil {
		panic("src.done already set")
	}
	srv.done = make(chan struct{})
	go ping(tick, srv.rescanTime, srv.done)
	<-ready
	return nil
}

// Stop stops the directory service.
func (srv *notifyService) Stop() error {
	close(srv.done)
	srv.done = nil
	return nil
}

func (srv *notifyService) notifyChange(reason box.UpdateReason, zid id.Zid) {
	if chci := srv.infos; chci != nil {
		chci <- box.UpdateInfo{Reason: reason, Zid: zid}
	}
}

// NumEntries returns the number of managed zettel.
func (srv *notifyService) NumEntries() (int, error) {
	resChan := make(chan resNumEntries)
	srv.cmds <- &cmdNumEntries{resChan}
	return <-resChan, nil
}

// GetEntries returns an unsorted list of all current directory entries.
func (srv *notifyService) GetEntries() ([]*directory.Entry, error) {
	resChan := make(chan resGetEntries)
	srv.cmds <- &cmdGetEntries{resChan}
	return <-resChan, nil
}

// GetEntry returns the entry with the specified zettel id. If there is no such
// zettel id, an empty entry is returned.
func (srv *notifyService) GetEntry(zid id.Zid) (*directory.Entry, error) {
	resChan := make(chan resGetEntry)
	srv.cmds <- &cmdGetEntry{zid, resChan}
	return <-resChan, nil
}

// GetNew returns an entry with a new zettel id.
func (srv *notifyService) GetNew() (*directory.Entry, error) {
	resChan := make(chan resNewEntry)
	srv.cmds <- &cmdNewEntry{resChan}
	result := <-resChan
	return result.entry, result.err
}

// UpdateEntry notifies the directory of an updated entry.
func (srv *notifyService) UpdateEntry(entry *directory.Entry) error {
	resChan := make(chan struct{})
	srv.cmds <- &cmdUpdateEntry{entry, resChan}
	<-resChan
	return nil
}

// RenameEntry notifies the directory of an renamed entry.
func (srv *notifyService) RenameEntry(curEntry, newEntry *directory.Entry) error {
	resChan := make(chan resRenameEntry)
	srv.cmds <- &cmdRenameEntry{curEntry, newEntry, resChan}
	return <-resChan
}

// DeleteEntry removes a zettel id from the directory of entries.
func (srv *notifyService) DeleteEntry(zid id.Zid) error {
	resChan := make(chan struct{})
	srv.cmds <- &cmdDeleteEntry{zid, resChan}
	<-resChan
	return nil
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package notifydir manages the notified directory part of a dirstore.
package notifydir

import (
	"log"
	"time"

	"zettelstore.de/z/box"
	"zettelstore.de/z/box/dirbox/directory"
	"zettelstore.de/z/domain/id"
)

// ping sends every tick a signal to reload the directory list
func ping(tick chan<- struct{}, rescanTime time.Duration, done <-chan struct{}) {
	ticker := time.NewTicker(rescanTime)
	defer close(tick)
	for {
		select {
		case _, ok := <-ticker.C:
			if !ok {
				return
			}
			tick <- struct{}{}
		case _, ok := <-done:
			if !ok {
				ticker.Stop()
				return
			}
		}
	}
}

func newEntry(ev *fileEvent) *directory.Entry {
	de := new(directory.Entry)
	de.Zid = ev.zid
	updateEntry(de, ev)
	return de
}

func updateEntry(de *directory.Entry, ev *fileEvent) {
	if ev.ext == "meta" {
		de.MetaSpec = directory.MetaSpecFile
		de.MetaPath = ev.path
		return
	}
	if de.ContentExt != "" && de.ContentExt != ev.ext {
		de.Duplicates = true
		return
	}
	if de.MetaSpec != directory.MetaSpecFile {
		if ev.ext == "zettel" {
			de.MetaSpec = directory.MetaSpecHeader
		} else {
			de.MetaSpec = directory.MetaSpecNone
		}
	}
	de.ContentPath = ev.path
	de.ContentExt = ev.ext
}

type dirMap map[id.Zid]*directory.Entry

func dirMapUpdate(dm dirMap, ev *fileEvent) {
	de := dm[ev.zid]
	if de == nil {
		dm[ev.zid] = newEntry(ev)
		return
	}
	updateEntry(de, ev)
}

func deleteFromMap(dm dirMap, ev *fileEvent) {
	if ev.ext == "meta" {
		if entry, ok := dm[ev.zid]; ok {
			if entry.MetaSpec == directory.MetaSpecFile {
				entry.MetaSpec = directory.MetaSpecNone
				return
			}
		}
	}
	delete(dm, ev.zid)
}

// directoryService is the main service.
func (srv *notifyService) directoryService(events <-chan *fileEvent, ready chan<- int) {
	curMap := make(dirMap)
	var newMap dirMap
	for {
		select {
		case ev, ok := <-events:
			if !ok {
				return
			}
			switch ev.status {
			case fileStatusReloadStart:
				newMap = make(dirMap)
			case fileStatusReloadEnd:
				curMap = newMap
				newMap = nil
				if ready != nil {
					ready <- len(curMap)
					close(ready)
					ready = nil
				}
				srv.notifyChange(box.OnReload, id.Invalid)
			case fileStatusError:
				log.Println("DIRBOX", "ERROR", ev.err)
			case fileStatusUpdate:
				srv.processFileUpdateEvent(ev, curMap, newMap)
			case fileStatusDelete:
				srv.processFileDeleteEvent(ev, curMap, newMap)
			}
		case cmd, ok := <-srv.cmds:
			if ok {
				cmd.run(curMap)
			}
		}
	}
}

func (srv *notifyService) processFileUpdateEvent(ev *fileEvent, curMap, newMap dirMap) {
	if newMap != nil {
		dirMapUpdate(newMap, ev)
	} else {
		dirMapUpdate(curMap, ev)
		srv.notifyChange(box.OnUpdate, ev.zid)
	}
}

func (srv *notifyService) processFileDeleteEvent(ev *fileEvent, curMap, newMap dirMap) {
	if newMap != nil {
		deleteFromMap(newMap, ev)
	} else {
		deleteFromMap(curMap, ev)
		srv.notifyChange(box.OnDelete, ev.zid)
	}
}

type dirCmd interface {
	run(m dirMap)
}

type cmdNumEntries struct {
	result chan<- resNumEntries
}
type resNumEntries = int

func (cmd *cmdNumEntries) run(m dirMap) {
	cmd.result <- len(m)
}

type cmdGetEntries struct {
	result chan<- resGetEntries
}
type resGetEntries []*directory.Entry

func (cmd *cmdGetEntries) run(m dirMap) {
	res := make([]*directory.Entry, len(m))
	i := 0
	for _, de := range m {
		entry := *de
		res[i] = &entry
		i++
	}
	cmd.result <- res
}

type cmdGetEntry struct {
	zid    id.Zid
	result chan<- resGetEntry
}
type resGetEntry = *directory.Entry

func (cmd *cmdGetEntry) run(m dirMap) {
	entry := m[cmd.zid]
	if entry == nil {
		cmd.result <- nil
	} else {
		result := *entry
		cmd.result <- &result
	}
}

type cmdNewEntry struct {
	result chan<- resNewEntry
}
type resNewEntry struct {
	entry *directory.Entry
	err   error
}

func (cmd *cmdNewEntry) run(m dirMap) {
	zid, err := box.GetNewZid(func(zid id.Zid) (bool, error) {
		_, ok := m[zid]
		return !ok, nil
	})
	if err != nil {
		cmd.result <- resNewEntry{nil, err}
		return
	}
	entry := &directory.Entry{Zid: zid}
	m[zid] = entry
	cmd.result <- resNewEntry{&directory.Entry{Zid: zid}, nil}
}

type cmdUpdateEntry struct {
	entry  *directory.Entry
	result chan<- struct{}
}

func (cmd *cmdUpdateEntry) run(m dirMap) {
	entry := *cmd.entry
	m[entry.Zid] = &entry
	cmd.result <- struct{}{}
}

type cmdRenameEntry struct {
	curEntry *directory.Entry
	newEntry *directory.Entry
	result   chan<- resRenameEntry
}

type resRenameEntry = error

func (cmd *cmdRenameEntry) run(m dirMap) {
	newEntry := *cmd.newEntry
	newZid := newEntry.Zid
	if _, found := m[newZid]; found {
		cmd.result <- &box.ErrInvalidID{Zid: newZid}
		return
	}
	delete(m, cmd.curEntry.Zid)
	m[newZid] = &newEntry
	cmd.result <- nil
}

type cmdDeleteEntry struct {
	zid    id.Zid
	result chan<- struct{}
}

func (cmd *cmdDeleteEntry) run(m dirMap) {
	delete(m, cmd.zid)
	cmd.result <- struct{}{}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package notifydir manages the notified directory part of a dirstore.
package notifydir

import (
	"os"
	"path/filepath"
	"regexp"
	"time"

	"github.com/fsnotify/fsnotify"

	"zettelstore.de/z/domain/id"
)

var validFileName = regexp.MustCompile(`^(\d{14}).*(\.(.+))$`)

func matchValidFileName(name string) []string {
	return validFileName.FindStringSubmatch(name)
}

type fileStatus int

const (
	fileStatusNone fileStatus = iota
	fileStatusReloadStart
	fileStatusReloadEnd
	fileStatusError
	fileStatusUpdate
	fileStatusDelete
)

type fileEvent struct {
	status fileStatus
	path   string // Full file path
	zid    id.Zid
	ext    string // File extension
	err    error  // Error if Status == fileStatusError
}

type sendResult int

const (
	sendDone sendResult = iota
	sendReload
	sendExit
)

func watchDirectory(directory string, events chan<- *fileEvent, tick <-chan struct{}) {
	defer close(events)

	var watcher *fsnotify.Watcher
	defer func() {
		if watcher != nil {
			watcher.Close()
		}
	}()

	sendEvent := func(ev *fileEvent) sendResult {
		select {
		case events <- ev:
		case _, ok := <-tick:
			if ok {
				return sendReload
			}
			return sendExit
		}
		return sendDone
	}

	sendError := func(err error) sendResult {
		return sendEvent(&fileEvent{status: fileStatusError, err: err})
	}

	sendFileEvent := func(status fileStatus, path string, match []string) sendResult {
		zid, err := id.Parse(match[1])
		if err != nil {
			return sendDone
		}
		event := &fileEvent{
			status: status,
			path:   path,
			zid:    zid,
			ext:    match[3],
		}
		return sendEvent(event)
	}

	reloadStartEvent := &fileEvent{status: fileStatusReloadStart}
	reloadEndEvent := &fileEvent{status: fileStatusReloadEnd}
	reloadFiles := func() bool {
		entries, err := os.ReadDir(directory)
		if err != nil {
			if res := sendError(err); res != sendDone {
				return res == sendReload
			}
			return true
		}

		if res := sendEvent(reloadStartEvent); res != sendDone {
			return res == sendReload
		}

		if watcher != nil {
			watcher.Close()
		}
		watcher, err = fsnotify.NewWatcher()
		if err != nil {
			if res := sendError(err); res != sendDone {
				return res == sendReload
			}
		}

		for _, entry := range entries {
			if entry.IsDir() {
				continue
			}
			if info, err1 := entry.Info(); err1 != nil || !info.Mode().IsRegular() {
				continue
			}
			name := entry.Name()
			match := matchValidFileName(name)
			if len(match) > 0 {
				path := filepath.Join(directory, name)
				if res := sendFileEvent(fileStatusUpdate, path, match); res != sendDone {
					return res == sendReload
				}
			}
		}

		if watcher != nil {
			err = watcher.Add(directory)
			if err != nil {
				if res := sendError(err); res != sendDone {
					return res == sendReload
				}
			}
		}
		if res := sendEvent(reloadEndEvent); res != sendDone {
			return res == sendReload
		}
		return true
	}

	handleEvents := func() bool {
		const createOps = fsnotify.Create | fsnotify.Write
		const deleteOps = fsnotify.Remove | fsnotify.Rename

		for {
			select {
			case wevent, ok := <-watcher.Events:
				if !ok {
					return false
				}
				path := filepath.Clean(wevent.Name)
				match := matchValidFileName(filepath.Base(path))
				if len(match) == 0 {
					continue
				}
				if wevent.Op&createOps != 0 {
					if fi, err := os.Lstat(path); err != nil || !fi.Mode().IsRegular() {
						continue
					}
					if res := sendFileEvent(
						fileStatusUpdate, path, match); res != sendDone {
						return res == sendReload
					}
				}
				if wevent.Op&deleteOps != 0 {
					if res := sendFileEvent(
						fileStatusDelete, path, match); res != sendDone {
						return res == sendReload
					}
				}
			case err, ok := <-watcher.Errors:
				if !ok {
					return false
				}
				if res := sendError(err); res != sendDone {
					return res == sendReload
				}
			case _, ok := <-tick:
				return ok
			}
		}
	}

	for {
		if !reloadFiles() {
			return
		}
		if watcher == nil {
			if _, ok := <-tick; !ok {
				return
			}
		} else {
			if !handleEvents() {
				return
			}
		}
	}
}

func sendCollectedEvents(out chan<- *fileEvent, events []*fileEvent) {
	for _, ev := range events {
		if ev.status != fileStatusNone {
			out <- ev
		}
	}
}

func addEvent(events []*fileEvent, ev *fileEvent) []*fileEvent {
	switch ev.status {
	case fileStatusNone:
		return events
	case fileStatusReloadStart:
		events = events[0:0]
	case fileStatusUpdate, fileStatusDelete:
		if len(events) > 0 && mergeEvents(events, ev) {
			return events
		}
	}
	return append(events, ev)
}

func mergeEvents(events []*fileEvent, ev *fileEvent) bool {
	for i := len(events) - 1; i >= 0; i-- {
		oev := events[i]
		switch oev.status {
		case fileStatusReloadStart, fileStatusReloadEnd:
			return false
		case fileStatusUpdate, fileStatusDelete:
			if ev.path == oev.path {
				if ev.status == oev.status {
					return true
				}
				oev.status = fileStatusNone
				return false
			}
		}
	}
	return false
}

func collectEvents(out chan<- *fileEvent, in <-chan *fileEvent) {
	defer close(out)

	var sendTime time.Time
	sendTimeSet := false
	ticker := time.NewTicker(500 * time.Millisecond)
	defer ticker.Stop()

	events := make([]*fileEvent, 0, 32)
	buffer := false
	for {
		select {
		case ev, ok := <-in:
			if !ok {
				sendCollectedEvents(out, events)
				return
			}
			if ev.status == fileStatusReloadStart {
				buffer = false
				events = events[0:0]
			}
			if buffer {
				if !sendTimeSet {
					sendTime = time.Now().Add(1500 * time.Millisecond)
					sendTimeSet = true
				}
				events = addEvent(events, ev)
				if len(events) > 1024 {
					sendCollectedEvents(out, events)
					events = events[0:0]
					sendTimeSet = false
				}
				continue
			}
			out <- ev
			if ev.status == fileStatusReloadEnd {
				buffer = true
			}
		case now := <-ticker.C:
			if sendTimeSet && now.After(sendTime) {
				sendCollectedEvents(out, events)
				events = events[0:0]
				sendTimeSet = false
			}
		}
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package notifydir manages the notified directory part of a dirstore.
package notifydir

import "testing"

func sameStringSlices(sl1, sl2 []string) bool {
	if len(sl1) != len(sl2) {
		return false
	}
	for i := 0; i < len(sl1); i++ {
		if sl1[i] != sl2[i] {
			return false
		}
	}
	return true
}

func TestMatchValidFileName(t *testing.T) {
	t.Parallel()
	testcases := []struct {
		name string
		exp  []string
	}{
		{"", []string{}},
		{".txt", []string{}},
		{"12345678901234.txt", []string{"12345678901234", ".txt", "txt"}},
		{"12345678901234abc.txt", []string{"12345678901234", ".txt", "txt"}},
		{"12345678901234.abc.txt", []string{"12345678901234", ".txt", "txt"}},
	}

	for i, tc := range testcases {
		got := matchValidFileName(tc.name)
		if len(got) == 0 {
			if len(tc.exp) > 0 {
				t.Errorf("TC=%d, name=%q, exp=%v, got=%v", i, tc.name, tc.exp, got)
			}
		} else {
			if got[0] != tc.name {
				t.Errorf("TC=%d, name=%q, got=%v", i, tc.name, got)
			}
			if !sameStringSlices(got[1:], tc.exp) {
				t.Errorf("TC=%d, name=%q, exp=%v, got=%v", i, tc.name, tc.exp, got)
			}
		}
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package dirbox provides a directory-based zettel box.
package dirbox

import (
	"os"

	"zettelstore.de/z/box/dirbox/directory"
	"zettelstore.de/z/box/filebox"
	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/input"
)

func fileService(num uint32, cmds <-chan fileCmd) {
	for cmd := range cmds {
		cmd.run()
	}
}

type fileCmd interface {
	run()
}

// COMMAND: getMeta ----------------------------------------
//
// Retrieves the meta data from a zettel.

func getMeta(dp *dirBox, entry *directory.Entry, zid id.Zid) (*meta.Meta, error) {
	rc := make(chan resGetMeta)
	dp.getFileChan(zid) <- &fileGetMeta{entry, rc}
	res := <-rc
	close(rc)
	return res.meta, res.err
}

type fileGetMeta struct {
	entry *directory.Entry
	rc    chan<- resGetMeta
}
type resGetMeta struct {
	meta *meta.Meta
	err  error
}

func (cmd *fileGetMeta) run() {
	entry := cmd.entry
	var m *meta.Meta
	var err error
	switch entry.MetaSpec {
	case directory.MetaSpecFile:
		m, err = parseMetaFile(entry.Zid, entry.MetaPath)
	case directory.MetaSpecHeader:
		m, _, err = parseMetaContentFile(entry.Zid, entry.ContentPath)
	default:
		m = filebox.CalcDefaultMeta(entry.Zid, entry.ContentExt)
	}
	if err == nil {
		cmdCleanupMeta(m, entry)
	}
	cmd.rc <- resGetMeta{m, err}
}

// COMMAND: getMetaContent ----------------------------------------
//
// Retrieves the meta data and the content of a zettel.

func getMetaContent(dp *dirBox, entry *directory.Entry, zid id.Zid) (*meta.Meta, string, error) {
	rc := make(chan resGetMetaContent)
	dp.getFileChan(zid) <- &fileGetMetaContent{entry, rc}
	res := <-rc
	close(rc)
	return res.meta, res.content, res.err
}

type fileGetMetaContent struct {
	entry *directory.Entry
	rc    chan<- resGetMetaContent
}
type resGetMetaContent struct {
	meta    *meta.Meta
	content string
	err     error
}

func (cmd *fileGetMetaContent) run() {
	var m *meta.Meta
	var content string
	var err error

	entry := cmd.entry
	switch entry.MetaSpec {
	case directory.MetaSpecFile:
		m, err = parseMetaFile(entry.Zid, entry.MetaPath)
		if err == nil {
			content, err = readFileContent(entry.ContentPath)
		}
	case directory.MetaSpecHeader:
		m, content, err = parseMetaContentFile(entry.Zid, entry.ContentPath)
	default:
		m = filebox.CalcDefaultMeta(entry.Zid, entry.ContentExt)
		content, err = readFileContent(entry.ContentPath)
	}
	if err == nil {
		cmdCleanupMeta(m, entry)
	}
	cmd.rc <- resGetMetaContent{m, content, err}
}

// COMMAND: setZettel ----------------------------------------
//
// Writes a new or exsting zettel.

func setZettel(dp *dirBox, entry *directory.Entry, zettel domain.Zettel) error {
	rc := make(chan resSetZettel)
	dp.getFileChan(zettel.Meta.Zid) <- &fileSetZettel{entry, zettel, rc}
	err := <-rc
	close(rc)
	return err
}

type fileSetZettel struct {
	entry  *directory.Entry
	zettel domain.Zettel
	rc     chan<- resSetZettel
}
type resSetZettel = error

func (cmd *fileSetZettel) run() {
	var err error
	switch cmd.entry.MetaSpec {
	case directory.MetaSpecFile:
		err = cmd.runMetaSpecFile()
	case directory.MetaSpecHeader:
		err = cmd.runMetaSpecHeader()
	case directory.MetaSpecNone:
		// TODO: if meta has some additional infos: write meta to new .meta;
		// update entry in dir
		err = writeFileContent(cmd.entry.ContentPath, cmd.zettel.Content.AsString())
	default:
		panic("TODO: ???")
	}
	cmd.rc <- err
}

func (cmd *fileSetZettel) runMetaSpecFile() error {
	f, err := openFileWrite(cmd.entry.MetaPath)
	if err == nil {
		err = writeFileZid(f, cmd.zettel.Meta.Zid)
		if err == nil {
			_, err = cmd.zettel.Meta.Write(f, true)
			if err1 := f.Close(); err == nil {
				err = err1
			}
			if err == nil {
				err = writeFileContent(cmd.entry.ContentPath, cmd.zettel.Content.AsString())
			}
		}
	}
	return err
}

func (cmd *fileSetZettel) runMetaSpecHeader() error {
	f, err := openFileWrite(cmd.entry.ContentPath)
	if err == nil {
		err = writeFileZid(f, cmd.zettel.Meta.Zid)
		if err == nil {
			_, err = cmd.zettel.Meta.WriteAsHeader(f, true)
			if err == nil {
				_, err = f.WriteString(cmd.zettel.Content.AsString())
				if err1 := f.Close(); err == nil {
					err = err1
				}
			}
		}
	}
	return err
}

// COMMAND: deleteZettel ----------------------------------------
//
// Deletes an existing zettel.

func deleteZettel(dp *dirBox, entry *directory.Entry, zid id.Zid) error {
	rc := make(chan resDeleteZettel)
	dp.getFileChan(zid) <- &fileDeleteZettel{entry, rc}
	err := <-rc
	close(rc)
	return err
}

type fileDeleteZettel struct {
	entry *directory.Entry
	rc    chan<- resDeleteZettel
}
type resDeleteZettel = error

func (cmd *fileDeleteZettel) run() {
	var err error

	switch cmd.entry.MetaSpec {
	case directory.MetaSpecFile:
		err1 := os.Remove(cmd.entry.MetaPath)
		err = os.Remove(cmd.entry.ContentPath)
		if err == nil {
			err = err1
		}
	case directory.MetaSpecHeader:
		err = os.Remove(cmd.entry.ContentPath)
	case directory.MetaSpecNone:
		err = os.Remove(cmd.entry.ContentPath)
	default:
		panic("TODO: ???")
	}
	cmd.rc <- err
}

// Utility functions ----------------------------------------

func readFileContent(path string) (string, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return "", err
	}
	return string(data), nil
}

func parseMetaFile(zid id.Zid, path string) (*meta.Meta, error) {
	src, err := readFileContent(path)
	if err != nil {
		return nil, err
	}
	inp := input.NewInput(src)
	return meta.NewFromInput(zid, inp), nil
}

func parseMetaContentFile(zid id.Zid, path string) (*meta.Meta, string, error) {
	src, err := readFileContent(path)
	if err != nil {
		return nil, "", err
	}
	inp := input.NewInput(src)
	meta := meta.NewFromInput(zid, inp)
	return meta, src[inp.Pos:], nil
}

func cmdCleanupMeta(m *meta.Meta, entry *directory.Entry) {
	filebox.CleanupMeta(
		m,
		entry.Zid, entry.ContentExt,
		entry.MetaSpec == directory.MetaSpecFile,
		entry.Duplicates,
	)
}

func openFileWrite(path string) (*os.File, error) {
	return os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
}

func writeFileZid(f *os.File, zid id.Zid) error {
	_, err := f.WriteString("id: ")
	if err == nil {
		_, err = f.Write(zid.Bytes())
		if err == nil {
			_, err = f.WriteString("\n")
		}
	}
	return err
}

func writeFileContent(path, content string) error {
	f, err := openFileWrite(path)
	if err == nil {
		_, err = f.WriteString(content)
		if err1 := f.Close(); err == nil {
			err = err1
		}
	}
	return err
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package simpledir manages the directory part of a dirstore.
package simpledir

import (
	"os"
	"path/filepath"
	"regexp"
	"sync"

	"zettelstore.de/z/box"
	"zettelstore.de/z/box/dirbox/directory"
	"zettelstore.de/z/domain/id"
)

// simpleService specifies a directory service without scanning.
type simpleService struct {
	dirPath string
	mx      sync.Mutex
}

// NewService creates a new directory service.
func NewService(directoryPath string) directory.Service {
	return &simpleService{
		dirPath: directoryPath,
	}
}

func (ss *simpleService) Start() error {
	ss.mx.Lock()
	defer ss.mx.Unlock()
	_, err := os.ReadDir(ss.dirPath)
	return err
}

func (ss *simpleService) Stop() error {
	return nil
}

func (ss *simpleService) NumEntries() (int, error) {
	ss.mx.Lock()
	defer ss.mx.Unlock()
	entries, err := ss.getEntries()
	if err == nil {
		return len(entries), nil
	}
	return 0, err
}

func (ss *simpleService) GetEntries() ([]*directory.Entry, error) {
	ss.mx.Lock()
	defer ss.mx.Unlock()
	entrySet, err := ss.getEntries()
	if err != nil {
		return nil, err
	}
	result := make([]*directory.Entry, 0, len(entrySet))
	for _, entry := range entrySet {
		result = append(result, entry)
	}
	return result, nil
}
func (ss *simpleService) getEntries() (map[id.Zid]*directory.Entry, error) {
	dirEntries, err := os.ReadDir(ss.dirPath)
	if err != nil {
		return nil, err
	}
	entrySet := make(map[id.Zid]*directory.Entry)
	for _, dirEntry := range dirEntries {
		if dirEntry.IsDir() {
			continue
		}
		if info, err1 := dirEntry.Info(); err1 != nil || !info.Mode().IsRegular() {
			continue
		}
		name := dirEntry.Name()
		match := matchValidFileName(name)
		if len(match) == 0 {
			continue
		}
		zid, err := id.Parse(match[1])
		if err != nil {
			continue
		}
		var entry *directory.Entry
		if e, ok := entrySet[zid]; ok {
			entry = e
		} else {
			entry = &directory.Entry{Zid: zid}
			entrySet[zid] = entry
		}
		updateEntry(entry, filepath.Join(ss.dirPath, name), match[3])
	}
	return entrySet, nil
}

var validFileName = regexp.MustCompile(`^(\d{14}).*(\.(.+))$`)

func matchValidFileName(name string) []string {
	return validFileName.FindStringSubmatch(name)
}

func updateEntry(entry *directory.Entry, path, ext string) {
	if ext == "meta" {
		entry.MetaSpec = directory.MetaSpecFile
		entry.MetaPath = path
	} else if entry.ContentExt != "" && entry.ContentExt != ext {
		entry.Duplicates = true
	} else {
		if entry.MetaSpec != directory.MetaSpecFile {
			if ext == "zettel" {
				entry.MetaSpec = directory.MetaSpecHeader
			} else {
				entry.MetaSpec = directory.MetaSpecNone
			}
		}
		entry.ContentPath = path
		entry.ContentExt = ext
	}
}

func (ss *simpleService) GetEntry(zid id.Zid) (*directory.Entry, error) {
	ss.mx.Lock()
	defer ss.mx.Unlock()
	return ss.getEntry(zid)
}
func (ss *simpleService) getEntry(zid id.Zid) (*directory.Entry, error) {
	pattern := filepath.Join(ss.dirPath, zid.String()) + "*.*"
	paths, err := filepath.Glob(pattern)
	if err != nil {
		return nil, err
	}
	if len(paths) == 0 {
		return nil, nil
	}
	entry := &directory.Entry{Zid: zid}
	for _, path := range paths {
		ext := filepath.Ext(path)
		if len(ext) > 0 && ext[0] == '.' {
			ext = ext[1:]
		}
		updateEntry(entry, path, ext)
	}
	return entry, nil
}

func (ss *simpleService) GetNew() (*directory.Entry, error) {
	ss.mx.Lock()
	defer ss.mx.Unlock()
	zid, err := box.GetNewZid(func(zid id.Zid) (bool, error) {
		entry, err := ss.getEntry(zid)
		if err != nil {
			return false, nil
		}
		return !entry.IsValid(), nil
	})
	if err != nil {
		return nil, err
	}
	return &directory.Entry{Zid: zid}, nil
}

func (ss *simpleService) UpdateEntry(entry *directory.Entry) error {
	// Nothing to to, since the actual file update is done by dirbox.
	return nil
}

func (ss *simpleService) RenameEntry(curEntry, newEntry *directory.Entry) error {
	// Nothing to to, since the actual file rename is done by dirbox.
	return nil
}

func (ss *simpleService) DeleteEntry(zid id.Zid) error {
	// Nothing to to, since the actual file delete is done by dirbox.
	return nil
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package filebox provides boxes that are stored in a file.
package filebox

import (
	"errors"
	"net/url"
	"path/filepath"
	"strings"

	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
)

func init() {
	manager.Register("file", func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
		path := getFilepathFromURL(u)
		ext := strings.ToLower(filepath.Ext(path))
		if ext != ".zip" {
			return nil, errors.New("unknown extension '" + ext + "' in box URL: " + u.String())
		}
		return &zipBox{
			number:   cdata.Number,
			name:     path,
			enricher: cdata.Enricher,
		}, nil
	})
}

func getFilepathFromURL(u *url.URL) string {
	name := u.Opaque
	if name == "" {
		name = u.Path
	}
	components := strings.Split(name, "/")
	fileName := filepath.Join(components...)
	if len(components) > 0 && components[0] == "" {
		return "/" + fileName
	}
	return fileName
}

var alternativeSyntax = map[string]string{
	"htm": "html",
}

func calculateSyntax(ext string) string {
	ext = strings.ToLower(ext)
	if syntax, ok := alternativeSyntax[ext]; ok {
		return syntax
	}
	return ext
}

// CalcDefaultMeta returns metadata with default values for the given entry.
func CalcDefaultMeta(zid id.Zid, ext string) *meta.Meta {
	m := meta.New(zid)
	m.Set(meta.KeyTitle, zid.String())
	m.Set(meta.KeySyntax, calculateSyntax(ext))
	return m
}

// CleanupMeta enhances the given metadata.
func CleanupMeta(m *meta.Meta, zid id.Zid, ext string, inMeta, duplicates bool) {
	if title, ok := m.Get(meta.KeyTitle); !ok || title == "" {
		m.Set(meta.KeyTitle, zid.String())
	}

	if inMeta {
		if syntax, ok := m.Get(meta.KeySyntax); !ok || syntax == "" {
			dm := CalcDefaultMeta(zid, ext)
			syntax, ok = dm.Get(meta.KeySyntax)
			if !ok {
				panic("Default meta must contain syntax")
			}
			m.Set(meta.KeySyntax, syntax)
		}
	}

	if duplicates {
		m.Set(meta.KeyDuplicates, meta.ValueTrue)
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package filebox provides boxes that are stored in a file.
package filebox

import (
	"archive/zip"
	"context"
	"io"
	"regexp"
	"strings"

	"zettelstore.de/z/box"
	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/input"
	"zettelstore.de/z/search"
)

var validFileName = regexp.MustCompile(`^(\d{14}).*(\.(.+))$`)

func matchValidFileName(name string) []string {
	return validFileName.FindStringSubmatch(name)
}

type zipEntry struct {
	metaName     string
	contentName  string
	contentExt   string // (normalized) file extension of zettel content
	metaInHeader bool
}

type zipBox struct {
	number   int
	name     string
	enricher box.Enricher
	zettel   map[id.Zid]*zipEntry // no lock needed, because read-only after creation
}

func (zp *zipBox) Location() string {
	if strings.HasPrefix(zp.name, "/") {
		return "file://" + zp.name
	}
	return "file:" + zp.name
}

func (zp *zipBox) Start(ctx context.Context) error {
	reader, err := zip.OpenReader(zp.name)
	if err != nil {
		return err
	}
	defer reader.Close()
	zp.zettel = make(map[id.Zid]*zipEntry)
	for _, f := range reader.File {
		match := matchValidFileName(f.Name)
		if len(match) < 1 {
			continue
		}
		zid, err := id.Parse(match[1])
		if err != nil {
			continue
		}
		zp.addFile(zid, f.Name, match[3])
	}
	return nil
}

func (zp *zipBox) addFile(zid id.Zid, name, ext string) {
	entry := zp.zettel[zid]
	if entry == nil {
		entry = &zipEntry{}
		zp.zettel[zid] = entry
	}
	switch ext {
	case "zettel":
		if entry.contentExt == "" {
			entry.contentName = name
			entry.contentExt = ext
			entry.metaInHeader = true
		}
	case "meta":
		entry.metaName = name
		entry.metaInHeader = false
	default:
		if entry.contentExt == "" {
			entry.contentExt = ext
			entry.contentName = name
		}
	}
}

func (zp *zipBox) Stop(ctx context.Context) error {
	zp.zettel = nil
	return nil
}

func (zp *zipBox) CanCreateZettel(ctx context.Context) bool { return false }

func (zp *zipBox) CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error) {
	return id.Invalid, box.ErrReadOnly
}

func (zp *zipBox) GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
	entry, ok := zp.zettel[zid]
	if !ok {
		return domain.Zettel{}, box.ErrNotFound
	}
	reader, err := zip.OpenReader(zp.name)
	if err != nil {
		return domain.Zettel{}, err
	}
	defer reader.Close()

	var m *meta.Meta
	var src string
	var inMeta bool
	if entry.metaInHeader {
		src, err = readZipFileContent(reader, entry.contentName)
		if err != nil {
			return domain.Zettel{}, err
		}
		inp := input.NewInput(src)
		m = meta.NewFromInput(zid, inp)
		src = src[inp.Pos:]
	} else if metaName := entry.metaName; metaName != "" {
		m, err = readZipMetaFile(reader, zid, metaName)
		if err != nil {
			return domain.Zettel{}, err
		}
		src, err = readZipFileContent(reader, entry.contentName)
		if err != nil {
			return domain.Zettel{}, err
		}
		inMeta = true
	} else {
		m = CalcDefaultMeta(zid, entry.contentExt)
	}
	CleanupMeta(m, zid, entry.contentExt, inMeta, false)
	return domain.Zettel{Meta: m, Content: domain.NewContent(src)}, nil
}

func (zp *zipBox) GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
	entry, ok := zp.zettel[zid]
	if !ok {
		return nil, box.ErrNotFound
	}
	reader, err := zip.OpenReader(zp.name)
	if err != nil {
		return nil, err
	}
	defer reader.Close()
	return readZipMeta(reader, zid, entry)
}

func (zp *zipBox) FetchZids(ctx context.Context) (id.Set, error) {
	result := id.NewSetCap(len(zp.zettel))
	for zid := range zp.zettel {
		result[zid] = true
	}
	return result, nil
}

func (zp *zipBox) SelectMeta(ctx context.Context, match search.MetaMatchFunc) (res []*meta.Meta, err error) {
	reader, err := zip.OpenReader(zp.name)
	if err != nil {
		return nil, err
	}
	defer reader.Close()
	for zid, entry := range zp.zettel {
		m, err := readZipMeta(reader, zid, entry)
		if err != nil {
			continue
		}
		zp.enricher.Enrich(ctx, m, zp.number)
		if match(m) {
			res = append(res, m)
		}
	}
	return res, nil
}

func (zp *zipBox) CanUpdateZettel(ctx context.Context, zettel domain.Zettel) bool {
	return false
}

func (zp *zipBox) UpdateZettel(ctx context.Context, zettel domain.Zettel) error {
	return box.ErrReadOnly
}

func (zp *zipBox) AllowRenameZettel(ctx context.Context, zid id.Zid) bool {
	_, ok := zp.zettel[zid]
	return !ok
}

func (zp *zipBox) RenameZettel(ctx context.Context, curZid, newZid id.Zid) error {
	if _, ok := zp.zettel[curZid]; ok {
		return box.ErrReadOnly
	}
	return box.ErrNotFound
}

func (zp *zipBox) CanDeleteZettel(ctx context.Context, zid id.Zid) bool { return false }

func (zp *zipBox) DeleteZettel(ctx context.Context, zid id.Zid) error {
	if _, ok := zp.zettel[zid]; ok {
		return box.ErrReadOnly
	}
	return box.ErrNotFound
}

func (zp *zipBox) ReadStats(st *box.ManagedBoxStats) {
	st.ReadOnly = true
	st.Zettel = len(zp.zettel)
}

func readZipMeta(reader *zip.ReadCloser, zid id.Zid, entry *zipEntry) (m *meta.Meta, err error) {
	var inMeta bool
	if entry.metaInHeader {
		m, err = readZipMetaFile(reader, zid, entry.contentName)
	} else if metaName := entry.metaName; metaName != "" {
		m, err = readZipMetaFile(reader, zid, entry.metaName)
		inMeta = true
	} else {
		m = CalcDefaultMeta(zid, entry.contentExt)
	}
	if err == nil {
		CleanupMeta(m, zid, entry.contentExt, inMeta, false)
	}
	return m, err
}

func readZipMetaFile(reader *zip.ReadCloser, zid id.Zid, name string) (*meta.Meta, error) {
	src, err := readZipFileContent(reader, name)
	if err != nil {
		return nil, err
	}
	inp := input.NewInput(src)
	return meta.NewFromInput(zid, inp), nil
}

func readZipFileContent(reader *zip.ReadCloser, name string) (string, error) {
	f, err := reader.Open(name)
	if err != nil {
		return "", err
	}
	defer f.Close()
	buf, err := io.ReadAll(f)
	if err != nil {
		return "", err
	}
	return string(buf), nil
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package box provides a generic interface to zettel boxes.
package box

import (
	"time"

	"zettelstore.de/z/domain/id"
)

// GetNewZid calculates a new and unused zettel identifier, based on the current date and time.
func GetNewZid(testZid func(id.Zid) (bool, error)) (id.Zid, error) {
	withSeconds := false
	for i := 0; i < 90; i++ { // Must be completed within 9 seconds (less than web/server.writeTimeout)
		zid := id.New(withSeconds)
		found, err := testZid(zid)
		if err != nil {
			return id.Invalid, err
		}
		if found {
			return zid, nil
		}
		// TODO: do not wait here unconditionally.
		time.Sleep(100 * time.Millisecond)
		withSeconds = true
	}
	return id.Invalid, ErrConflict
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package manager coordinates the various boxes and indexes of a Zettelstore.
package manager

import (
	"sync"

	"zettelstore.de/z/domain/id"
)

type arAction int

const (
	arNothing arAction = iota
	arReload
	arUpdate
	arDelete
)

type anteroom struct {
	num     uint64
	next    *anteroom
	waiting map[id.Zid]arAction
	curLoad int
	reload  bool
}

type anterooms struct {
	mx      sync.Mutex
	nextNum uint64
	first   *anteroom
	last    *anteroom
	maxLoad int
}

func newAnterooms(maxLoad int) *anterooms {
	return &anterooms{maxLoad: maxLoad}
}

func (ar *anterooms) Enqueue(zid id.Zid, action arAction) {
	if !zid.IsValid() || action == arNothing || action == arReload {
		return
	}
	ar.mx.Lock()
	defer ar.mx.Unlock()
	if ar.first == nil {
		ar.first = ar.makeAnteroom(zid, action)
		ar.last = ar.first
		return
	}
	for room := ar.first; room != nil; room = room.next {
		if room.reload {
			continue // Do not put zettel in reload room
		}
		a, ok := room.waiting[zid]
		if !ok {
			continue
		}
		switch action {
		case a:
			return
		case arUpdate:
			room.waiting[zid] = action
		case arDelete:
			room.waiting[zid] = action
		}
		return
	}
	if room := ar.last; !room.reload && (ar.maxLoad == 0 || room.curLoad < ar.maxLoad) {
		room.waiting[zid] = action
		room.curLoad++
		return
	}
	room := ar.makeAnteroom(zid, action)
	ar.last.next = room
	ar.last = room
}

func (ar *anterooms) makeAnteroom(zid id.Zid, action arAction) *anteroom {
	c := ar.maxLoad
	if c == 0 {
		c = 100
	}
	waiting := make(map[id.Zid]arAction, c)
	waiting[zid] = action
	ar.nextNum++
	return &anteroom{num: ar.nextNum, next: nil, waiting: waiting, curLoad: 1, reload: false}
}

func (ar *anterooms) Reset() {
	ar.mx.Lock()
	defer ar.mx.Unlock()
	ar.first = ar.makeAnteroom(id.Invalid, arReload)
	ar.last = ar.first
}

func (ar *anterooms) Reload(newZids id.Set) uint64 {
	ar.mx.Lock()
	defer ar.mx.Unlock()
	newWaiting := createWaitingSet(newZids, arUpdate)
	ar.deleteReloadedRooms()

	if ns := len(newWaiting); ns > 0 {
		ar.nextNum++
		ar.first = &anteroom{num: ar.nextNum, next: ar.first, waiting: newWaiting, curLoad: ns}
		if ar.first.next == nil {
			ar.last = ar.first
		}
		return ar.nextNum
	}

	ar.first = nil
	ar.last = nil
	return 0
}

func createWaitingSet(zids id.Set, action arAction) map[id.Zid]arAction {
	waitingSet := make(map[id.Zid]arAction, len(zids))
	for zid := range zids {
		if zid.IsValid() {
			waitingSet[zid] = action
		}
	}
	return waitingSet
}

func (ar *anterooms) deleteReloadedRooms() {
	room := ar.first
	for room != nil && room.reload {
		room = room.next
	}
	ar.first = room
	if room == nil {
		ar.last = nil
	}
}

func (ar *anterooms) Dequeue() (arAction, id.Zid, uint64) {
	ar.mx.Lock()
	defer ar.mx.Unlock()
	if ar.first == nil {
		return arNothing, id.Invalid, 0
	}
	for zid, action := range ar.first.waiting {
		roomNo := ar.first.num
		delete(ar.first.waiting, zid)
		if len(ar.first.waiting) == 0 {
			ar.first = ar.first.next
			if ar.first == nil {
				ar.last = nil
			}
		}
		return action, zid, roomNo
	}
	return arNothing, id.Invalid, 0
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package manager coordinates the various boxes and indexes of a Zettelstore.
package manager

import (
	"testing"

	"zettelstore.de/z/domain/id"
)

func TestSimple(t *testing.T) {
	t.Parallel()
	ar := newAnterooms(2)
	ar.Enqueue(id.Zid(1), arUpdate)
	action, zid, rno := ar.Dequeue()
	if zid != id.Zid(1) || action != arUpdate || rno != 1 {
		t.Errorf("Expected arUpdate/1/1, but got %v/%v/%v", action, zid, rno)
	}
	action, zid, _ = ar.Dequeue()
	if zid != id.Invalid && action != arDelete {
		t.Errorf("Expected invalid Zid, but got %v", zid)
	}
	ar.Enqueue(id.Zid(1), arUpdate)
	ar.Enqueue(id.Zid(2), arUpdate)
	if ar.first != ar.last {
		t.Errorf("Expected one room, but got more")
	}
	ar.Enqueue(id.Zid(3), arUpdate)
	if ar.first == ar.last {
		t.Errorf("Expected more than one room, but got only one")
	}

	count := 0
	for ; count < 1000; count++ {
		action, _, _ := ar.Dequeue()
		if action == arNothing {
			break
		}
	}
	if count != 3 {
		t.Errorf("Expected 3 dequeues, but got %v", count)
	}
}

func TestReset(t *testing.T) {
	t.Parallel()
	ar := newAnterooms(1)
	ar.Enqueue(id.Zid(1), arUpdate)
	ar.Reset()
	action, zid, _ := ar.Dequeue()
	if action != arReload || zid != id.Invalid {
		t.Errorf("Expected reload & invalid Zid, but got %v/%v", action, zid)
	}
	ar.Reload(id.NewSet(3, 4))
	ar.Enqueue(id.Zid(5), arUpdate)
	ar.Enqueue(id.Zid(5), arDelete)
	ar.Enqueue(id.Zid(5), arDelete)
	ar.Enqueue(id.Zid(5), arUpdate)
	if ar.first == ar.last || ar.first.next != ar.last /*|| ar.first.next.next != ar.last*/ {
		t.Errorf("Expected 2 rooms")
	}
	action, zid1, _ := ar.Dequeue()
	if action != arUpdate {
		t.Errorf("Expected arUpdate, but got %v", action)
	}
	action, zid2, _ := ar.Dequeue()
	if action != arUpdate {
		t.Errorf("Expected arUpdate, but got %v", action)
	}
	if !(zid1 == id.Zid(3) && zid2 == id.Zid(4) || zid1 == id.Zid(4) && zid2 == id.Zid(3)) {
		t.Errorf("Zids must be 3 or 4, but got %v/%v", zid1, zid2)
	}
	action, zid, _ = ar.Dequeue()
	if zid != id.Zid(5) || action != arUpdate {
		t.Errorf("Expected 5/arUpdate, but got %v/%v", zid, action)
	}
	action, zid, _ = ar.Dequeue()
	if action != arNothing || zid != id.Invalid {
		t.Errorf("Expected nothing & invalid Zid, but got %v/%v", action, zid)
	}

	ar = newAnterooms(1)
	ar.Reload(id.NewSet(id.Zid(6)))
	action, zid, _ = ar.Dequeue()
	if zid != id.Zid(6) || action != arUpdate {
		t.Errorf("Expected 6/arUpdate, but got %v/%v", zid, action)
	}
	action, zid, _ = ar.Dequeue()
	if action != arNothing || zid != id.Invalid {
		t.Errorf("Expected nothing & invalid Zid, but got %v/%v", action, zid)
	}

	ar = newAnterooms(1)
	ar.Enqueue(id.Zid(8), arUpdate)
	ar.Reload(nil)
	action, zid, _ = ar.Dequeue()
	if action != arNothing || zid != id.Invalid {
		t.Errorf("Expected nothing & invalid Zid, but got %v/%v", action, zid)
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package manager coordinates the various boxes and indexes of a Zettelstore.
package manager

import (
	"context"
	"errors"
	"sort"
	"strings"

	"zettelstore.de/z/box"
	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/search"
)

// Conatains all box.Box related functions

// Location returns some information where the box is located.
func (mgr *Manager) Location() string {
	if len(mgr.boxes) <= 2 {
		return "NONE"
	}
	var sb strings.Builder
	for i := 0; i < len(mgr.boxes)-2; i++ {
		if i > 0 {
			sb.WriteString(", ")
		}
		sb.WriteString(mgr.boxes[i].Location())
	}
	return sb.String()
}

// CanCreateZettel returns true, if box could possibly create a new zettel.
func (mgr *Manager) CanCreateZettel(ctx context.Context) bool {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	return mgr.started && mgr.boxes[0].CanCreateZettel(ctx)
}

// CreateZettel creates a new zettel.
func (mgr *Manager) CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error) {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return id.Invalid, box.ErrStopped
	}
	return mgr.boxes[0].CreateZettel(ctx, zettel)
}

// GetZettel retrieves a specific zettel.
func (mgr *Manager) GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return domain.Zettel{}, box.ErrStopped
	}
	for i, p := range mgr.boxes {
		if z, err := p.GetZettel(ctx, zid); err != box.ErrNotFound {
			if err == nil {
				mgr.Enrich(ctx, z.Meta, i+1)
			}
			return z, err
		}
	}
	return domain.Zettel{}, box.ErrNotFound
}

// GetAllZettel retrieves a specific zettel from all managed boxes.
func (mgr *Manager) GetAllZettel(ctx context.Context, zid id.Zid) ([]domain.Zettel, error) {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return nil, box.ErrStopped
	}
	var result []domain.Zettel
	for i, p := range mgr.boxes {
		if z, err := p.GetZettel(ctx, zid); err == nil {
			mgr.Enrich(ctx, z.Meta, i+1)
			result = append(result, z)
		}
	}
	return result, nil
}

// GetMeta retrieves just the meta data of a specific zettel.
func (mgr *Manager) GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return nil, box.ErrStopped
	}
	for i, p := range mgr.boxes {
		if m, err := p.GetMeta(ctx, zid); err != box.ErrNotFound {
			if err == nil {
				mgr.Enrich(ctx, m, i+1)
			}
			return m, err
		}
	}
	return nil, box.ErrNotFound
}

// GetAllMeta retrieves the meta data of a specific zettel from all managed boxes.
func (mgr *Manager) GetAllMeta(ctx context.Context, zid id.Zid) ([]*meta.Meta, error) {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return nil, box.ErrStopped
	}
	var result []*meta.Meta
	for i, p := range mgr.boxes {
		if m, err := p.GetMeta(ctx, zid); err == nil {
			mgr.Enrich(ctx, m, i+1)
			result = append(result, m)
		}
	}
	return result, nil
}

// FetchZids returns the set of all zettel identifer managed by the box.
func (mgr *Manager) FetchZids(ctx context.Context) (result id.Set, err error) {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return nil, box.ErrStopped
	}
	for _, p := range mgr.boxes {
		zids, err := p.FetchZids(ctx)
		if err != nil {
			return nil, err
		}
		if result == nil {
			result = zids
		} else if len(result) <= len(zids) {
			for zid := range result {
				zids[zid] = true
			}
			result = zids
		} else {
			for zid := range zids {
				result[zid] = true
			}
		}
	}
	return result, nil
}

// SelectMeta returns all zettel meta data that match the selection
// criteria. The result is ordered by descending zettel id.
func (mgr *Manager) SelectMeta(ctx context.Context, s *search.Search) ([]*meta.Meta, error) {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return nil, box.ErrStopped
	}
	var result []*meta.Meta
	match := s.CompileMatch(mgr)
	for _, p := range mgr.boxes {
		selected, err := p.SelectMeta(ctx, match)
		if err != nil {
			return nil, err
		}
		sort.Slice(selected, func(i, j int) bool { return selected[i].Zid > selected[j].Zid })
		if len(result) == 0 {
			result = selected
		} else {
			result = box.MergeSorted(result, selected)
		}
	}
	if s == nil {
		return result, nil
	}
	return s.Sort(result), nil
}

// CanUpdateZettel returns true, if box could possibly update the given zettel.
func (mgr *Manager) CanUpdateZettel(ctx context.Context, zettel domain.Zettel) bool {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	return mgr.started && mgr.boxes[0].CanUpdateZettel(ctx, zettel)
}

// UpdateZettel updates an existing zettel.
func (mgr *Manager) UpdateZettel(ctx context.Context, zettel domain.Zettel) error {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return box.ErrStopped
	}
	// Remove all (computed) properties from metadata before storing the zettel.
	zettel.Meta = zettel.Meta.Clone()
	for _, p := range zettel.Meta.PairsRest(true) {
		if mgr.propertyKeys[p.Key] {
			zettel.Meta.Delete(p.Key)
		}
	}
	return mgr.boxes[0].UpdateZettel(ctx, zettel)
}

// AllowRenameZettel returns true, if box will not disallow renaming the zettel.
func (mgr *Manager) AllowRenameZettel(ctx context.Context, zid id.Zid) bool {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return false
	}
	for _, p := range mgr.boxes {
		if !p.AllowRenameZettel(ctx, zid) {
			return false
		}
	}
	return true
}

// RenameZettel changes the current zid to a new zid.
func (mgr *Manager) RenameZettel(ctx context.Context, curZid, newZid id.Zid) error {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return box.ErrStopped
	}
	for i, p := range mgr.boxes {
		err := p.RenameZettel(ctx, curZid, newZid)
		if err != nil && !errors.Is(err, box.ErrNotFound) {
			for j := 0; j < i; j++ {
				mgr.boxes[j].RenameZettel(ctx, newZid, curZid)
			}
			return err
		}
	}
	return nil
}

// CanDeleteZettel returns true, if box could possibly delete the given zettel.
func (mgr *Manager) CanDeleteZettel(ctx context.Context, zid id.Zid) bool {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return false
	}
	for _, p := range mgr.boxes {
		if p.CanDeleteZettel(ctx, zid) {
			return true
		}
	}
	return false
}

// DeleteZettel removes the zettel from the box.
func (mgr *Manager) DeleteZettel(ctx context.Context, zid id.Zid) error {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return box.ErrStopped
	}
	for _, p := range mgr.boxes {
		err := p.DeleteZettel(ctx, zid)
		if err == nil {
			return nil
		}
		if !errors.Is(err, box.ErrNotFound) && !errors.Is(err, box.ErrReadOnly) {
			return err
		}
	}
	return box.ErrNotFound
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package manager coordinates the various boxes and indexes of a Zettelstore.
package manager

import (
	"strings"

	"zettelstore.de/z/ast"
	"zettelstore.de/z/box/manager/store"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/strfun"
)

type collectData struct {
	refs  id.Set
	words store.WordSet
	urls  store.WordSet
}

func (data *collectData) initialize() {
	data.refs = id.NewSet()
	data.words = store.NewWordSet()
	data.urls = store.NewWordSet()
}

func collectZettelIndexData(zn *ast.ZettelNode, data *collectData) {
	ast.WalkBlockSlice(data, zn.Ast)
}

func collectInlineIndexData(ins ast.InlineSlice, data *collectData) {
	ast.WalkInlineSlice(data, ins)
}

func (data *collectData) Visit(node ast.Node) ast.Visitor {
	switch n := node.(type) {
	case *ast.VerbatimNode:
		for _, line := range n.Lines {
			data.addText(line)
		}
	case *ast.TextNode:
		data.addText(n.Text)
	case *ast.TagNode:
		data.addText(n.Tag)
	case *ast.LinkNode:
		data.addRef(n.Ref)
	case *ast.ImageNode:
		data.addRef(n.Ref)
	case *ast.LiteralNode:
		data.addText(n.Text)
	}
	return data
}

func (data *collectData) addText(s string) {
	for _, word := range strfun.NormalizeWords(s) {
		data.words.Add(word)
	}
}

func (data *collectData) addRef(ref *ast.Reference) {
	if ref == nil {
		return
	}
	if ref.IsExternal() {
		data.urls.Add(strings.ToLower(ref.Value))
	}
	if !ref.IsZettel() {
		return
	}
	if zid, err := id.Parse(ref.URL.Path); err == nil {
		data.refs[zid] = true
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package manager coordinates the various boxes and indexes of a Zettelstore.
package manager

import (
	"context"
	"strconv"

	"zettelstore.de/z/box"
	"zettelstore.de/z/domain/meta"
)

// Enrich computes additional properties and updates the given metadata.
func (mgr *Manager) Enrich(ctx context.Context, m *meta.Meta, boxNumber int) {
	if box.DoNotEnrich(ctx) {
		// Enrich is called indirectly via indexer or enrichment is not requested
		// because of other reasons -> ignore this call, do not update meta data
		return
	}
	m.Set(meta.KeyBoxNumber, strconv.Itoa(boxNumber))
	computePublished(m)
	mgr.idxStore.Enrich(ctx, m)
}

func computePublished(m *meta.Meta) {
	if _, ok := m.Get(meta.KeyPublished); ok {
		return
	}
	if modified, ok := m.Get(meta.KeyModified); ok {
		if _, ok = meta.TimeValue(modified); ok {
			m.Set(meta.KeyPublished, modified)
			return
		}
	}
	zid := m.Zid.String()
	if _, ok := meta.TimeValue(zid); ok {
		m.Set(meta.KeyPublished, zid)
		return
	}

	// Neither the zettel was modified nor the zettel identifer contains a valid
	// timestamp. In this case do not set the "published" property.
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package manager coordinates the various boxes and indexes of a Zettelstore.
package manager

import (
	"context"
	"net/url"
	"time"

	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager/store"
	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/strfun"
)

// SearchEqual returns all zettel that contains the given exact word.
// The word must be normalized through Unicode NKFD, trimmed and not empty.
func (mgr *Manager) SearchEqual(word string) id.Set {
	return mgr.idxStore.SearchEqual(word)
}

// SearchPrefix returns all zettel that have a word with the given prefix.
// The prefix must be normalized through Unicode NKFD, trimmed and not empty.
func (mgr *Manager) SearchPrefix(prefix string) id.Set {
	return mgr.idxStore.SearchPrefix(prefix)
}

// SearchSuffix returns all zettel that have a word with the given suffix.
// The suffix must be normalized through Unicode NKFD, trimmed and not empty.
func (mgr *Manager) SearchSuffix(suffix string) id.Set {
	return mgr.idxStore.SearchSuffix(suffix)
}

// SearchContains returns all zettel that contains the given string.
// The string must be normalized through Unicode NKFD, trimmed and not empty.
func (mgr *Manager) SearchContains(s string) id.Set {
	return mgr.idxStore.SearchContains(s)
}

// idxIndexer runs in the background and updates the index data structures.
// This is the main service of the idxIndexer.
func (mgr *Manager) idxIndexer() {
	// Something may panic. Ensure a running indexer.
	defer func() {
		if r := recover(); r != nil {
			kernel.Main.LogRecover("Indexer", r)
			go mgr.idxIndexer()
		}
	}()

	timerDuration := 15 * time.Second
	timer := time.NewTimer(timerDuration)
	ctx := box.NoEnrichContext(context.Background())
	for {
		mgr.idxWorkService(ctx)
		if !mgr.idxSleepService(timer, timerDuration) {
			return
		}
	}
}

func (mgr *Manager) idxWorkService(ctx context.Context) {
	var roomNum uint64
	var start time.Time
	for {
		switch action, zid, arRoomNum := mgr.idxAr.Dequeue(); action {
		case arNothing:
			return
		case arReload:
			roomNum = 0
			zids, err := mgr.FetchZids(ctx)
			if err == nil {
				start = time.Now()
				if rno := mgr.idxAr.Reload(zids); rno > 0 {
					roomNum = rno
				}
				mgr.idxMx.Lock()
				mgr.idxLastReload = time.Now()
				mgr.idxSinceReload = 0
				mgr.idxMx.Unlock()
			}
		case arUpdate:
			zettel, err := mgr.GetZettel(ctx, zid)
			if err != nil {
				// TODO: on some errors put the zid into a "try later" set
				continue
			}
			mgr.idxMx.Lock()
			if arRoomNum == roomNum {
				mgr.idxDurReload = time.Since(start)
			}
			mgr.idxSinceReload++
			mgr.idxMx.Unlock()
			mgr.idxUpdateZettel(ctx, zettel)
		case arDelete:
			if _, err := mgr.GetMeta(ctx, zid); err == nil {
				// Zettel was not deleted. This might occur, if zettel was
				// deleted in secondary dirbox, but is still present in
				// first dirbox (or vice versa). Re-index zettel in case
				// a hidden zettel was recovered
				mgr.idxAr.Enqueue(zid, arUpdate)
			}
			mgr.idxMx.Lock()
			mgr.idxSinceReload++
			mgr.idxMx.Unlock()
			mgr.idxDeleteZettel(zid)
		}
	}
}

func (mgr *Manager) idxSleepService(timer *time.Timer, timerDuration time.Duration) bool {
	select {
	case _, ok := <-mgr.idxReady:
		if !ok {
			return false
		}
	case _, ok := <-timer.C:
		if !ok {
			return false
		}
		timer.Reset(timerDuration)
	case <-mgr.done:
		if !timer.Stop() {
			<-timer.C
		}
		return false
	}
	return true
}

func (mgr *Manager) idxUpdateZettel(ctx context.Context, zettel domain.Zettel) {
	m := zettel.Meta
	if m.GetBool(meta.KeyNoIndex) {
		// Zettel maybe in index
		toCheck := mgr.idxStore.DeleteZettel(ctx, m.Zid)
		mgr.idxCheckZettel(toCheck)
		return
	}

	var cData collectData
	cData.initialize()
	collectZettelIndexData(parser.ParseZettel(zettel, "", mgr.rtConfig), &cData)
	zi := store.NewZettelIndex(m.Zid)
	mgr.idxCollectFromMeta(ctx, m, zi, &cData)
	mgr.idxProcessData(ctx, zi, &cData)
	toCheck := mgr.idxStore.UpdateReferences(ctx, zi)
	mgr.idxCheckZettel(toCheck)
}

func (mgr *Manager) idxCollectFromMeta(ctx context.Context, m *meta.Meta, zi *store.ZettelIndex, cData *collectData) {
	for _, pair := range m.Pairs(false) {
		descr := meta.GetDescription(pair.Key)
		if descr.IsComputed() {
			continue
		}
		switch descr.Type {
		case meta.TypeID:
			mgr.idxUpdateValue(ctx, descr.Inverse, pair.Value, zi)
		case meta.TypeIDSet:
			for _, val := range meta.ListFromValue(pair.Value) {
				mgr.idxUpdateValue(ctx, descr.Inverse, val, zi)
			}
		case meta.TypeZettelmarkup:
			collectInlineIndexData(parser.ParseMetadata(pair.Value), cData)
		case meta.TypeURL:
			if _, err := url.Parse(pair.Value); err == nil {
				cData.urls.Add(pair.Value)
			}
		default:
			for _, word := range strfun.NormalizeWords(pair.Value) {
				cData.words.Add(word)
			}
		}
	}
}

func (mgr *Manager) idxProcessData(ctx context.Context, zi *store.ZettelIndex, cData *collectData) {
	for ref := range cData.refs {
		if _, err := mgr.GetMeta(ctx, ref); err == nil {
			zi.AddBackRef(ref)
		} else {
			zi.AddDeadRef(ref)
		}
	}
	zi.SetWords(cData.words)
	zi.SetUrls(cData.urls)
}

func (mgr *Manager) idxUpdateValue(ctx context.Context, inverseKey, value string, zi *store.ZettelIndex) {
	zid, err := id.Parse(value)
	if err != nil {
		return
	}
	if _, err := mgr.GetMeta(ctx, zid); err != nil {
		zi.AddDeadRef(zid)
		return
	}
	if inverseKey == "" {
		zi.AddBackRef(zid)
		return
	}
	zi.AddMetaRef(inverseKey, zid)
}

func (mgr *Manager) idxDeleteZettel(zid id.Zid) {
	toCheck := mgr.idxStore.DeleteZettel(context.Background(), zid)
	mgr.idxCheckZettel(toCheck)
}

func (mgr *Manager) idxCheckZettel(s id.Set) {
	for zid := range s {
		mgr.idxAr.Enqueue(zid, arUpdate)
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package manager coordinates the various boxes and indexes of a Zettelstore.
package manager

import (
	"context"
	"io"
	"log"
	"net/url"
	"sort"
	"sync"
	"time"

	"zettelstore.de/z/auth"
	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager/memstore"
	"zettelstore.de/z/box/manager/store"
	"zettelstore.de/z/config"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/kernel"
)

// ConnectData contains all administration related values.
type ConnectData struct {
	Number   int // number of the box, starting with 1.
	Config   config.Config
	Enricher box.Enricher
	Notify   chan<- box.UpdateInfo
}

// Connect returns a handle to the specified box.
func Connect(u *url.URL, authManager auth.BaseManager, cdata *ConnectData) (box.ManagedBox, error) {
	if authManager.IsReadonly() {
		rawURL := u.String()
		// TODO: the following is wrong under some circumstances:
		// 1. fragment is set
		if q := u.Query(); len(q) == 0 {
			rawURL += "?readonly"
		} else if _, ok := q["readonly"]; !ok {
			rawURL += "&readonly"
		}
		var err error
		if u, err = url.Parse(rawURL); err != nil {
			return nil, err
		}
	}

	if create, ok := registry[u.Scheme]; ok {
		return create(u, cdata)
	}
	return nil, &ErrInvalidScheme{u.Scheme}
}

// ErrInvalidScheme is returned if there is no box with the given scheme.
type ErrInvalidScheme struct{ Scheme string }

func (err *ErrInvalidScheme) Error() string { return "Invalid scheme: " + err.Scheme }

type createFunc func(*url.URL, *ConnectData) (box.ManagedBox, error)

var registry = map[string]createFunc{}

// Register the encoder for later retrieval.
func Register(scheme string, create createFunc) {
	if _, ok := registry[scheme]; ok {
		log.Fatalf("Box with scheme %q already registered", scheme)
	}
	registry[scheme] = create
}

// GetSchemes returns all registered scheme, ordered by scheme string.
func GetSchemes() []string {
	result := make([]string, 0, len(registry))
	for scheme := range registry {
		result = append(result, scheme)
	}
	sort.Strings(result)
	return result
}

// Manager is a coordinating box.
type Manager struct {
	mgrMx        sync.RWMutex
	started      bool
	rtConfig     config.Config
	boxes        []box.ManagedBox
	observers    []box.UpdateFunc
	mxObserver   sync.RWMutex
	done         chan struct{}
	infos        chan box.UpdateInfo
	propertyKeys map[string]bool // Set of property key names

	// Indexer data
	idxStore store.Store
	idxAr    *anterooms
	idxReady chan struct{} // Signal a non-empty anteroom to background task

	// Indexer stats data
	idxMx          sync.RWMutex
	idxLastReload  time.Time
	idxDurReload   time.Duration
	idxSinceReload uint64
}

// New creates a new managing box.
func New(boxURIs []*url.URL, authManager auth.BaseManager, rtConfig config.Config) (*Manager, error) {
	propertyKeys := make(map[string]bool)
	for _, kd := range meta.GetSortedKeyDescriptions() {
		if kd.IsProperty() {
			propertyKeys[kd.Name] = true
		}
	}
	mgr := &Manager{
		rtConfig:     rtConfig,
		infos:        make(chan box.UpdateInfo, len(boxURIs)*10),
		propertyKeys: propertyKeys,

		idxStore: memstore.New(),
		idxAr:    newAnterooms(10),
		idxReady: make(chan struct{}, 1),
	}
	cdata := ConnectData{Number: 1, Config: rtConfig, Enricher: mgr, Notify: mgr.infos}
	boxes := make([]box.ManagedBox, 0, len(boxURIs)+2)
	for _, uri := range boxURIs {
		p, err := Connect(uri, authManager, &cdata)
		if err != nil {
			return nil, err
		}
		if p != nil {
			boxes = append(boxes, p)
			cdata.Number++
		}
	}
	constbox, err := registry[" const"](nil, &cdata)
	if err != nil {
		return nil, err
	}
	cdata.Number++
	compbox, err := registry[" comp"](nil, &cdata)
	if err != nil {
		return nil, err
	}
	cdata.Number++
	boxes = append(boxes, constbox, compbox)
	mgr.boxes = boxes
	return mgr, nil
}

// RegisterObserver registers an observer that will be notified
// if a zettel was found to be changed.
func (mgr *Manager) RegisterObserver(f box.UpdateFunc) {
	if f != nil {
		mgr.mxObserver.Lock()
		mgr.observers = append(mgr.observers, f)
		mgr.mxObserver.Unlock()
	}
}

func (mgr *Manager) notifyObserver(ci *box.UpdateInfo) {
	mgr.mxObserver.RLock()
	observers := mgr.observers
	mgr.mxObserver.RUnlock()
	for _, ob := range observers {
		ob(*ci)
	}
}

func (mgr *Manager) notifier() {
	// The call to notify may panic. Ensure a running notifier.
	defer func() {
		if r := recover(); r != nil {
			kernel.Main.LogRecover("Notifier", r)
			go mgr.notifier()
		}
	}()

	for {
		select {
		case ci, ok := <-mgr.infos:
			if ok {
				mgr.idxEnqueue(ci.Reason, ci.Zid)
				if ci.Box == nil {
					ci.Box = mgr
				}
				mgr.notifyObserver(&ci)
			}
		case <-mgr.done:
			return
		}
	}
}

func (mgr *Manager) idxEnqueue(reason box.UpdateReason, zid id.Zid) {
	switch reason {
	case box.OnReload:
		mgr.idxAr.Reset()
	case box.OnUpdate:
		mgr.idxAr.Enqueue(zid, arUpdate)
	case box.OnDelete:
		mgr.idxAr.Enqueue(zid, arDelete)
	default:
		return
	}
	select {
	case mgr.idxReady <- struct{}{}:
	default:
	}
}

// Start the box. Now all other functions of the box are allowed.
// Starting an already started box is not allowed.
func (mgr *Manager) Start(ctx context.Context) error {
	mgr.mgrMx.Lock()
	if mgr.started {
		mgr.mgrMx.Unlock()
		return box.ErrStarted
	}
	for i := len(mgr.boxes) - 1; i >= 0; i-- {
		ssi, ok := mgr.boxes[i].(box.StartStopper)
		if !ok {
			continue
		}
		err := ssi.Start(ctx)
		if err == nil {
			continue
		}
		for j := i + 1; j < len(mgr.boxes); j++ {
			if ssj, ok := mgr.boxes[j].(box.StartStopper); ok {
				ssj.Stop(ctx)
			}
		}
		mgr.mgrMx.Unlock()
		return err
	}
	mgr.idxAr.Reset() // Ensure an initial index run
	mgr.done = make(chan struct{})
	go mgr.notifier()
	go mgr.idxIndexer()

	// mgr.startIndexer(mgr)
	mgr.started = true
	mgr.mgrMx.Unlock()
	mgr.infos <- box.UpdateInfo{Reason: box.OnReload, Zid: id.Invalid}
	return nil
}

// Stop the started box. Now only the Start() function is allowed.
func (mgr *Manager) Stop(ctx context.Context) error {
	mgr.mgrMx.Lock()
	defer mgr.mgrMx.Unlock()
	if !mgr.started {
		return box.ErrStopped
	}
	close(mgr.done)
	var err error
	for _, p := range mgr.boxes {
		if ss, ok := p.(box.StartStopper); ok {
			if err1 := ss.Stop(ctx); err1 != nil && err == nil {
				err = err1
			}
		}
	}
	mgr.started = false
	return err
}

// ReadStats populates st with box statistics.
func (mgr *Manager) ReadStats(st *box.Stats) {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	subStats := make([]box.ManagedBoxStats, len(mgr.boxes))
	for i, p := range mgr.boxes {
		p.ReadStats(&subStats[i])
	}

	st.ReadOnly = true
	sumZettel := 0
	for _, sst := range subStats {
		if !sst.ReadOnly {
			st.ReadOnly = false
		}
		sumZettel += sst.Zettel
	}
	st.NumManagedBoxes = len(mgr.boxes)
	st.ZettelTotal = sumZettel

	var storeSt store.Stats
	mgr.idxMx.RLock()
	defer mgr.idxMx.RUnlock()
	mgr.idxStore.ReadStats(&storeSt)

	st.LastReload = mgr.idxLastReload
	st.IndexesSinceReload = mgr.idxSinceReload
	st.DurLastReload = mgr.idxDurReload
	st.ZettelIndexed = storeSt.Zettel
	st.IndexUpdates = storeSt.Updates
	st.IndexedWords = storeSt.Words
	st.IndexedUrls = storeSt.Urls
}

// Dump internal data structures to a Writer.
func (mgr *Manager) Dump(w io.Writer) {
	mgr.idxStore.Dump(w)
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
//
// This file is part of zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package memstore stored the index in main memory.
package memstore

import (
	"context"
	"fmt"
	"io"
	"sort"
	"strings"
	"sync"

	"zettelstore.de/z/box/manager/store"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
)

type metaRefs struct {
	forward  id.Slice
	backward id.Slice
}

type zettelIndex struct {
	dead     id.Slice
	forward  id.Slice
	backward id.Slice
	meta     map[string]metaRefs
	words    []string
	urls     []string
}

func (zi *zettelIndex) isEmpty() bool {
	if len(zi.forward) > 0 || len(zi.backward) > 0 || len(zi.dead) > 0 || len(zi.words) > 0 {
		return false
	}
	return zi.meta == nil || len(zi.meta) == 0
}

type stringRefs map[string]id.Slice

type memStore struct {
	mx    sync.RWMutex
	idx   map[id.Zid]*zettelIndex
	dead  map[id.Zid]id.Slice // map dead refs where they occur
	words stringRefs
	urls  stringRefs

	// Stats
	updates uint64
}

// New returns a new memory-based index store.
func New() store.Store {
	return &memStore{
		idx:   make(map[id.Zid]*zettelIndex),
		dead:  make(map[id.Zid]id.Slice),
		words: make(stringRefs),
		urls:  make(stringRefs),
	}
}

func (ms *memStore) Enrich(ctx context.Context, m *meta.Meta) {
	if ms.doEnrich(ctx, m) {
		ms.mx.Lock()
		ms.updates++
		ms.mx.Unlock()
	}
}

func (ms *memStore) doEnrich(ctx context.Context, m *meta.Meta) bool {
	ms.mx.RLock()
	defer ms.mx.RUnlock()
	zi, ok := ms.idx[m.Zid]
	if !ok {
		return false
	}
	var updated bool
	if len(zi.dead) > 0 {
		m.Set(meta.KeyDead, zi.dead.String())
		updated = true
	}
	back := removeOtherMetaRefs(m, zi.backward.Copy())
	if len(zi.backward) > 0 {
		m.Set(meta.KeyBackward, zi.backward.String())
		updated = true
	}
	if len(zi.forward) > 0 {
		m.Set(meta.KeyForward, zi.forward.String())
		back = remRefs(back, zi.forward)
		updated = true
	}
	if len(zi.meta) > 0 {
		for k, refs := range zi.meta {
			if len(refs.backward) > 0 {
				m.Set(k, refs.backward.String())
				back = remRefs(back, refs.backward)
				updated = true
			}
		}
	}
	if len(back) > 0 {
		m.Set(meta.KeyBack, back.String())
		updated = true
	}
	return updated
}

// SearchEqual returns all zettel that contains the given exact word.
// The word must be normalized through Unicode NKFD, trimmed and not empty.
func (ms *memStore) SearchEqual(word string) id.Set {
	ms.mx.RLock()
	defer ms.mx.RUnlock()
	result := id.NewSet()
	if refs, ok := ms.words[word]; ok {
		result.AddSlice(refs)
	}
	if refs, ok := ms.urls[word]; ok {
		result.AddSlice(refs)
	}
	zid, err := id.Parse(word)
	if err != nil {
		return result
	}
	zi, ok := ms.idx[zid]
	if !ok {
		return result
	}

	addBackwardZids(result, zid, zi)
	return result
}

// SearchPrefix returns all zettel that have a word with the given prefix.
// The prefix must be normalized through Unicode NKFD, trimmed and not empty.
func (ms *memStore) SearchPrefix(prefix string) id.Set {
	ms.mx.RLock()
	defer ms.mx.RUnlock()
	result := ms.selectWithPred(prefix, strings.HasPrefix)
	l := len(prefix)
	if l > 14 {
		return result
	}
	minZid, err := id.Parse(prefix + "00000000000000"[:14-l])
	if err != nil {
		return result
	}
	maxZid, err := id.Parse(prefix + "99999999999999"[:14-l])
	if err != nil {
		return result
	}
	for zid, zi := range ms.idx {
		if minZid <= zid && zid <= maxZid {
			addBackwardZids(result, zid, zi)
		}
	}
	return result
}

// SearchSuffix returns all zettel that have a word with the given suffix.
// The suffix must be normalized through Unicode NKFD, trimmed and not empty.
func (ms *memStore) SearchSuffix(suffix string) id.Set {
	ms.mx.RLock()
	defer ms.mx.RUnlock()
	result := ms.selectWithPred(suffix, strings.HasSuffix)
	l := len(suffix)
	if l > 14 {
		return result
	}
	val, err := id.ParseUint(suffix)
	if err != nil {
		return result
	}
	modulo := uint64(1)
	for i := 0; i < l; i++ {
		modulo *= 10
	}
	for zid, zi := range ms.idx {
		if uint64(zid)%modulo == val {
			addBackwardZids(result, zid, zi)
		}
	}
	return result
}

// SearchContains returns all zettel that contains the given string.
// The string must be normalized through Unicode NKFD, trimmed and not empty.
func (ms *memStore) SearchContains(s string) id.Set {
	ms.mx.RLock()
	defer ms.mx.RUnlock()
	result := ms.selectWithPred(s, strings.Contains)
	if len(s) > 14 {
		return result
	}
	if _, err := id.ParseUint(s); err != nil {
		return result
	}
	for zid, zi := range ms.idx {
		if strings.Contains(zid.String(), s) {
			addBackwardZids(result, zid, zi)
		}
	}
	return result
}

func (ms *memStore) selectWithPred(s string, pred func(string, string) bool) id.Set {
	// Must only be called if ms.mx is read-locked!
	result := id.NewSet()
	for word, refs := range ms.words {
		if !pred(word, s) {
			continue
		}
		result.AddSlice(refs)
	}
	for u, refs := range ms.urls {
		if !pred(u, s) {
			continue
		}
		result.AddSlice(refs)
	}
	return result
}

func addBackwardZids(result id.Set, zid id.Zid, zi *zettelIndex) {
	// Must only be called if ms.mx is read-locked!
	result[zid] = true
	result.AddSlice(zi.backward)
	for _, mref := range zi.meta {
		result.AddSlice(mref.backward)
	}
}

func removeOtherMetaRefs(m *meta.Meta, back id.Slice) id.Slice {
	for _, p := range m.PairsRest(false) {
		switch meta.Type(p.Key) {
		case meta.TypeID:
			if zid, err := id.Parse(p.Value); err == nil {
				back = remRef(back, zid)
			}
		case meta.TypeIDSet:
			for _, val := range meta.ListFromValue(p.Value) {
				if zid, err := id.Parse(val); err == nil {
					back = remRef(back, zid)
				}
			}
		}
	}
	return back
}

func (ms *memStore) UpdateReferences(ctx context.Context, zidx *store.ZettelIndex) id.Set {
	ms.mx.Lock()
	defer ms.mx.Unlock()
	zi, ziExist := ms.idx[zidx.Zid]
	if !ziExist || zi == nil {
		zi = &zettelIndex{}
		ziExist = false
	}

	// Is this zettel an old dead reference mentioned in other zettel?
	var toCheck id.Set
	if refs, ok := ms.dead[zidx.Zid]; ok {
		// These must be checked later again
		toCheck = id.NewSet(refs...)
		delete(ms.dead, zidx.Zid)
	}

	ms.updateDeadReferences(zidx, zi)
	ms.updateForwardBackwardReferences(zidx, zi)
	ms.updateMetadataReferences(zidx, zi)
	zi.words = updateWordSet(zidx.Zid, ms.words, zi.words, zidx.GetWords())
	zi.urls = updateWordSet(zidx.Zid, ms.urls, zi.urls, zidx.GetUrls())

	// Check if zi must be inserted into ms.idx
	if !ziExist && !zi.isEmpty() {
		ms.idx[zidx.Zid] = zi
	}

	return toCheck
}

func (ms *memStore) updateDeadReferences(zidx *store.ZettelIndex, zi *zettelIndex) {
	// Must only be called if ms.mx is write-locked!
	drefs := zidx.GetDeadRefs()
	newRefs, remRefs := refsDiff(drefs, zi.dead)
	zi.dead = drefs
	for _, ref := range remRefs {
		ms.dead[ref] = remRef(ms.dead[ref], zidx.Zid)
	}
	for _, ref := range newRefs {
		ms.dead[ref] = addRef(ms.dead[ref], zidx.Zid)
	}
}

func (ms *memStore) updateForwardBackwardReferences(zidx *store.ZettelIndex, zi *zettelIndex) {
	// Must only be called if ms.mx is write-locked!
	brefs := zidx.GetBackRefs()
	newRefs, remRefs := refsDiff(brefs, zi.forward)
	zi.forward = brefs
	for _, ref := range remRefs {
		bzi := ms.getEntry(ref)
		bzi.backward = remRef(bzi.backward, zidx.Zid)
	}
	for _, ref := range newRefs {
		bzi := ms.getEntry(ref)
		bzi.backward = addRef(bzi.backward, zidx.Zid)
	}
}

func (ms *memStore) updateMetadataReferences(zidx *store.ZettelIndex, zi *zettelIndex) {
	// Must only be called if ms.mx is write-locked!
	metarefs := zidx.GetMetaRefs()
	for key, mr := range zi.meta {
		if _, ok := metarefs[key]; ok {
			continue
		}
		ms.removeInverseMeta(zidx.Zid, key, mr.forward)
	}
	if zi.meta == nil {
		zi.meta = make(map[string]metaRefs)
	}
	for key, mrefs := range metarefs {
		mr := zi.meta[key]
		newRefs, remRefs := refsDiff(mrefs, mr.forward)
		mr.forward = mrefs
		zi.meta[key] = mr

		for _, ref := range newRefs {
			bzi := ms.getEntry(ref)
			if bzi.meta == nil {
				bzi.meta = make(map[string]metaRefs)
			}
			bmr := bzi.meta[key]
			bmr.backward = addRef(bmr.backward, zidx.Zid)
			bzi.meta[key] = bmr
		}
		ms.removeInverseMeta(zidx.Zid, key, remRefs)
	}
}

func updateWordSet(zid id.Zid, srefs stringRefs, prev []string, next store.WordSet) []string {
	// Must only be called if ms.mx is write-locked!
	newWords, removeWords := next.Diff(prev)
	for _, word := range newWords {
		if refs, ok := srefs[word]; ok {
			srefs[word] = addRef(refs, zid)
			continue
		}
		srefs[word] = id.Slice{zid}
	}
	for _, word := range removeWords {
		refs, ok := srefs[word]
		if !ok {
			continue
		}
		refs2 := remRef(refs, zid)
		if len(refs2) == 0 {
			delete(srefs, word)
			continue
		}
		srefs[word] = refs2
	}
	return next.Words()
}

func (ms *memStore) getEntry(zid id.Zid) *zettelIndex {
	// Must only be called if ms.mx is write-locked!
	if zi, ok := ms.idx[zid]; ok {
		return zi
	}
	zi := &zettelIndex{}
	ms.idx[zid] = zi
	return zi
}

func (ms *memStore) DeleteZettel(ctx context.Context, zid id.Zid) id.Set {
	ms.mx.Lock()
	defer ms.mx.Unlock()

	zi, ok := ms.idx[zid]
	if !ok {
		return nil
	}

	ms.deleteDeadSources(zid, zi)
	toCheck := ms.deleteForwardBackward(zid, zi)
	if len(zi.meta) > 0 {
		for key, mrefs := range zi.meta {
			ms.removeInverseMeta(zid, key, mrefs.forward)
		}
	}
	ms.deleteWords(zid, zi.words)
	delete(ms.idx, zid)
	return toCheck
}

func (ms *memStore) deleteDeadSources(zid id.Zid, zi *zettelIndex) {
	// Must only be called if ms.mx is write-locked!
	for _, ref := range zi.dead {
		if drefs, ok := ms.dead[ref]; ok {
			drefs = remRef(drefs, zid)
			if len(drefs) > 0 {
				ms.dead[ref] = drefs
			} else {
				delete(ms.dead, ref)
			}
		}
	}
}

func (ms *memStore) deleteForwardBackward(zid id.Zid, zi *zettelIndex) id.Set {
	// Must only be called if ms.mx is write-locked!
	var toCheck id.Set
	for _, ref := range zi.forward {
		if fzi, ok := ms.idx[ref]; ok {
			fzi.backward = remRef(fzi.backward, zid)
		}
	}
	for _, ref := range zi.backward {
		if bzi, ok := ms.idx[ref]; ok {
			bzi.forward = remRef(bzi.forward, zid)
			if toCheck == nil {
				toCheck = id.NewSet()
			}
			toCheck[ref] = true
		}
	}
	return toCheck
}

func (ms *memStore) removeInverseMeta(zid id.Zid, key string, forward id.Slice) {
	// Must only be called if ms.mx is write-locked!
	for _, ref := range forward {
		bzi, ok := ms.idx[ref]
		if !ok || bzi.meta == nil {
			continue
		}
		bmr, ok := bzi.meta[key]
		if !ok {
			continue
		}
		bmr.backward = remRef(bmr.backward, zid)
		if len(bmr.backward) > 0 || len(bmr.forward) > 0 {
			bzi.meta[key] = bmr
		} else {
			delete(bzi.meta, key)
			if len(bzi.meta) == 0 {
				bzi.meta = nil
			}
		}
	}
}

func (ms *memStore) deleteWords(zid id.Zid, words []string) {
	// Must only be called if ms.mx is write-locked!
	for _, word := range words {
		refs, ok := ms.words[word]
		if !ok {
			continue
		}
		refs2 := remRef(refs, zid)
		if len(refs2) == 0 {
			delete(ms.words, word)
			continue
		}
		ms.words[word] = refs2
	}
}

func (ms *memStore) ReadStats(st *store.Stats) {
	ms.mx.RLock()
	st.Zettel = len(ms.idx)
	st.Updates = ms.updates
	st.Words = uint64(len(ms.words))
	st.Urls = uint64(len(ms.urls))
	ms.mx.RUnlock()
}

func (ms *memStore) Dump(w io.Writer) {
	ms.mx.RLock()
	defer ms.mx.RUnlock()

	io.WriteString(w, "=== Dump\n")
	ms.dumpIndex(w)
	ms.dumpDead(w)
	dumpStringRefs(w, "Words", "", "", ms.words)
	dumpStringRefs(w, "URLs", "[[", "]]", ms.urls)
}

func (ms *memStore) dumpIndex(w io.Writer) {
	if len(ms.idx) == 0 {
		return
	}
	io.WriteString(w, "==== Zettel Index\n")
	zids := make(id.Slice, 0, len(ms.idx))
	for id := range ms.idx {
		zids = append(zids, id)
	}
	zids.Sort()
	for _, id := range zids {
		fmt.Fprintln(w, "=====", id)
		zi := ms.idx[id]
		if len(zi.dead) > 0 {
			fmt.Fprintln(w, "* Dead:", zi.dead)
		}
		dumpZids(w, "* Forward:", zi.forward)
		dumpZids(w, "* Backward:", zi.backward)
		for k, fb := range zi.meta {
			fmt.Fprintln(w, "* Meta", k)
			dumpZids(w, "** Forward:", fb.forward)
			dumpZids(w, "** Backward:", fb.backward)
		}
		dumpStrings(w, "* Words", "", "", zi.words)
		dumpStrings(w, "* URLs", "[[", "]]", zi.urls)
	}
}

func (ms *memStore) dumpDead(w io.Writer) {
	if len(ms.dead) == 0 {
		return
	}
	fmt.Fprintf(w, "==== Dead References\n")
	zids := make(id.Slice, 0, len(ms.dead))
	for id := range ms.dead {
		zids = append(zids, id)
	}
	zids.Sort()
	for _, id := range zids {
		fmt.Fprintln(w, ";", id)
		fmt.Fprintln(w, ":", ms.dead[id])
	}
}

func dumpZids(w io.Writer, prefix string, zids id.Slice) {
	if len(zids) > 0 {
		io.WriteString(w, prefix)
		for _, zid := range zids {
			io.WriteString(w, " ")
			w.Write(zid.Bytes())
		}
		fmt.Fprintln(w)
	}
}

func dumpStrings(w io.Writer, title, preString, postString string, slice []string) {
	if len(slice) > 0 {
		sl := make([]string, len(slice))
		copy(sl, slice)
		sort.Strings(sl)
		fmt.Fprintln(w, title)
		for _, s := range sl {
			fmt.Fprintf(w, "** %s%s%s\n", preString, s, postString)
		}
	}

}

func dumpStringRefs(w io.Writer, title, preString, postString string, srefs stringRefs) {
	if len(srefs) == 0 {
		return
	}
	fmt.Fprintln(w, "====", title)
	slice := make([]string, 0, len(srefs))
	for s := range srefs {
		slice = append(slice, s)
	}
	sort.Strings(slice)
	for _, s := range slice {
		fmt.Fprintf(w, "; %s%s%s\n", preString, s, postString)
		fmt.Fprintln(w, ":", srefs[s])
	}
}