bin/*
releases/*
parser/pikchr/*.out

## Copyright (c) 2020-present 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.

.PHONY:  check relcheck api build release clean

check:
	go run tools/build.go check

relcheck:
	go run tools/build.go relcheck

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

gradually, one major focus is a long-term store of these notes, hence the name
“Zettelstore”.

To get an initial impression, take a look at the
[manual](https://zettelstore.de/manual/). It is a live example of the
zettelstore software, running in read-only mode.

[Zettelstore Client](https://zettelstore.de/client) provides client
software to access Zettelstore via its API more easily, [Zettelstore
Contrib](https://zettelstore.de/contrib) contains contributed software, which
often connects to Zettelstore via its API. Some of the software packages may be
experimental.

The software, including the manual, is licensed
under the [European Union Public License 1.2 (or
later)](https://zettelstore.de/home/file?name=LICENSE.txt&ci=trunk).

0.13.0

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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 for parsed zettel content.
package ast

import (
	"net/url"

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

// ZettelNode is the root node of the abstract syntax tree.
// It is *not* part of the visitor pattern.
type ZettelNode struct {
	Meta    *meta.Meta     // Original metadata
	Content zettel.Content // Original content
	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.
	Syntax  string         // Syntax / parser that produced the Ast
}

// 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()
}

// ItemNode is a node that can occur as a list item.
type ItemNode interface {
	BlockNode
	itemNode()
}

// ItemSlice is a slice of ItemNodes.
type ItemSlice []ItemNode

// DescriptionNode is a node that contains just textual description.
type DescriptionNode interface {
	ItemNode
	descriptionNode()
}

// DescriptionSlice is a slice of DescriptionNodes.
type DescriptionSlice []DescriptionNode

// InlineNode is the interface that all inline nodes must implement.
type InlineNode interface {
	Node
	inlineNode()
}

// Reference is a reference to external or internal material.
type Reference struct {
	URL   *url.URL
	Value string
	State RefState
}

// RefState indicates the state of the reference.
type RefState int

// Constants for RefState
const (
	RefStateInvalid  RefState = iota // Invalid Reference
	RefStateZettel                   // Reference to an internal zettel
	RefStateSelf                     // Reference to same zettel with a fragment
	RefStateFound                    // Reference to an existing internal zettel, URL is ajusted
	RefStateBroken                   // Reference to a non-existing internal zettel
	RefStateHosted                   // Reference to local hosted non-Zettel, without URL change
	RefStateBased                    // Reference to local non-Zettel, to be prefixed
	RefStateQuery                    // Reference to a zettel query
	RefStateExternal                 // Reference to external material
)

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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

import "zettelstore.de/client.fossil/attrs"

// Definition of Block nodes.

// BlockSlice is a slice of BlockNodes.
type BlockSlice []BlockNode

func (*BlockSlice) blockNode() { /* Just a marker */ }

// WalkChildren walks down to the descriptions.
func (bs *BlockSlice) WalkChildren(v Visitor) {
	if bs != nil {
		for _, bn := range *bs {
			Walk(v, bn)
		}
	}
}

// FirstParagraphInlines returns the inline list of the first paragraph that
// contains a inline list.
func (bs BlockSlice) FirstParagraphInlines() InlineSlice {
	for _, bn := range bs {
		pn, ok := bn.(*ParaNode)
		if !ok {
			continue
		}
		if inl := pn.Inlines; len(inl) > 0 {
			return inl
		}
	}
	return nil
}

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

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

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

// CreateParaNode creates a parameter block from inline nodes.
func CreateParaNode(nodes ...InlineNode) *ParaNode { return &ParaNode{Inlines: nodes} }

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

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

// VerbatimNode contains uninterpreted text
type VerbatimNode struct {
	Kind    VerbatimKind
	Attrs   attrs.Attributes
	Content []byte
}

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

// Constants for VerbatimCode
const (
	_               VerbatimKind = iota
	VerbatimZettel               // Zettel content
	VerbatimProg                 // Program code
	VerbatimEval                 // Code to be externally interpreted. Syntax is stored in default attribute.
	VerbatimComment              // Block comment
	VerbatimHTML                 // Block HTML, e.g. for Markdown
	VerbatimMath                 // Block math mode
)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

// NestedListNode specifies a nestable list, either ordered or unordered.
type NestedListNode struct {
	Kind  NestedListKind
	Items []ItemSlice
	Attrs 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 (*NestedListNode) blockNode() { /* Just a marker */ }
func (*NestedListNode) itemNode()  { /* Just a marker */ }

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

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

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

// Description is one element of a description list.
type Description struct {
	Term         InlineSlice
	Descriptions []DescriptionSlice
}

func (*DescriptionListNode) blockNode() { /* Just a marker */ }

// WalkChildren walks down to the descriptions.
func (dn *DescriptionListNode) WalkChildren(v Visitor) {
	if descrs := dn.Descriptions; descrs != nil {
		for i, desc := range descrs {
			if len(desc.Term) > 0 {
				Walk(v, &descrs[i].Term) // Otherwise, changes in desc.Term will not go back into AST
			}
			if dss := desc.Descriptions; dss != nil {
				for _, dns := range dss {
					WalkDescriptionSlice(v, dns)
				}
			}
		}
	}
}

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

// TableNode specifies a full table
type TableNode struct {
	Header TableRow    // The header row
	Align  []Alignment // Default column alignment
	Rows   []TableRow  // The slice of cell rows
}

// TableCell contains the data for one table cell
type TableCell struct {
	Align   Alignment   // Cell alignment
	Inlines InlineSlice // Cell content
}

// TableRow is a slice of cells.
type TableRow []*TableCell

// Alignment specifies text alignment.
// Currently only for tables.
type Alignment int

// Constants for Alignment.
const (
	_            Alignment = iota
	AlignDefault           // Default alignment, inherited
	AlignLeft              // Left alignment
	AlignCenter            // Center the content
	AlignRight             // Right alignment
)

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

// WalkChildren walks down to the cells.
func (tn *TableNode) WalkChildren(v Visitor) {
	if header := tn.Header; header != nil {
		for i := range header {
			Walk(v, &header[i].Inlines) // Otherwise changes will not go back
		}
	}
	if rows := tn.Rows; rows != nil {
		for _, row := range rows {
			for i := range row {
				Walk(v, &row[i].Inlines) // Otherwise changes will not go back
			}
		}
	}
}

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

// TranscludeNode specifies block content from other zettel to embedded in
// current zettel
type TranscludeNode struct {
	Attrs attrs.Attributes
	Ref   *Reference
}

func (*TranscludeNode) blockNode() { /* Just a marker */ }

// WalkChildren does nothing.
func (*TranscludeNode) WalkChildren(Visitor) { /* No children*/ }

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

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

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

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

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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

import (
	"unicode/utf8"

	"zettelstore.de/client.fossil/attrs"
)

// Definitions of inline nodes.

// InlineSlice is a list of BlockNodes.
type InlineSlice []InlineNode

func (*InlineSlice) inlineNode() { /* Just a marker */ }

// CreateInlineSliceFromWords makes a new inline list from words,
// that will be space-separated.
func CreateInlineSliceFromWords(words ...string) InlineSlice {
	inl := make(InlineSlice, 0, 2*len(words)-1)
	for i, word := range words {
		if i > 0 {
			inl = append(inl, &SpaceNode{Lexeme: " "})
		}
		inl = append(inl, &TextNode{Text: word})
	}
	return inl
}

// WalkChildren walks down to the list.
func (is *InlineSlice) WalkChildren(v Visitor) {
	for _, in := range *is {
		Walk(v, in)
	}
}

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

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

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

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

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

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

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

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

// Count returns the number of space runes.
func (sn *SpaceNode) Count() int {
	return utf8.RuneCountInString(sn.Lexeme)
}

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

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

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

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

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

// LinkNode contains the specified link.
type LinkNode struct {
	Attrs   attrs.Attributes // Optional attributes
	Ref     *Reference
	Inlines InlineSlice // The text associated with the link.
}

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

// WalkChildren walks to the link text.
func (ln *LinkNode) WalkChildren(v Visitor) {
	if len(ln.Inlines) > 0 {
		Walk(v, &ln.Inlines)
	}
}

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

// EmbedRefNode contains the specified embedded reference material.
type EmbedRefNode struct {
	Attrs   attrs.Attributes // Optional attributes
	Ref     *Reference       // The reference to be embedded.
	Syntax  string           // Syntax of referenced material, if known
	Inlines InlineSlice      // Optional text associated with the image.
}

func (*EmbedRefNode) inlineNode() { /* Just a marker */ }

// WalkChildren walks to the text that describes the embedded material.
func (en *EmbedRefNode) WalkChildren(v Visitor) { Walk(v, &en.Inlines) }

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

// EmbedBLOBNode contains the specified embedded BLOB material.
type EmbedBLOBNode struct {
	Attrs   attrs.Attributes // Optional attributes
	Syntax  string           // Syntax of Blob
	Blob    []byte           // BLOB data itself.
	Inlines InlineSlice      // Optional text associated with the image.
}

func (*EmbedBLOBNode) inlineNode() { /* Just a marker */ }

// WalkChildren walks to the text that describes the embedded material.
func (en *EmbedBLOBNode) WalkChildren(v Visitor) { Walk(v, &en.Inlines) }

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

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

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

// WalkChildren walks to the cite text.
func (cn *CiteNode) WalkChildren(v Visitor) { Walk(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 {
	Mark     string      // The mark text itself
	Slug     string      // Slugified form of Mark
	Fragment string      // Unique form of Slug
	Inlines  InlineSlice // Marked inline content
}

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

// WalkChildren does nothing.
func (mn *MarkNode) WalkChildren(v Visitor) {
	if len(mn.Inlines) > 0 {
		Walk(v, &mn.Inlines)
	}
}

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

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

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

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

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

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

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

// Constants for FormatCode
const (
	_            FormatKind = iota
	FormatEmph              // Emphasized text.
	FormatStrong            // Strongly emphasized text.
	FormatInsert            // Inserted text.
	FormatDelete            // Deleted text.
	FormatSuper             // Superscripted text.
	FormatSub               // SubscriptedText.
	FormatQuote             // Quoted text.
	FormatSpan              // Generic inline container.
)

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

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

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

// LiteralNode specifies some uninterpreted text.
type LiteralNode struct {
	Kind    LiteralKind
	Attrs   attrs.Attributes // Optional attributes.
	Content []byte
}

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

// Constants for LiteralCode
const (
	_              LiteralKind = iota
	LiteralZettel              // Zettel content
	LiteralProg                // Inline program code
	LiteralInput               // Computer input, e.g. Keyboard strokes
	LiteralOutput              // Computer output
	LiteralComment             // Inline comment
	LiteralHTML                // Inline HTML, e.g. for Markdown
	LiteralMath                // Inline math mode
)

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

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

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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

import (
	"net/url"
	"strings"

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

// QueryPrefix is the prefix that denotes a query expression.
const QueryPrefix = "query:"

// ParseReference parses a string and returns a reference.
func ParseReference(s string) *Reference {
	if invalidReference(s) {
		return &Reference{URL: nil, Value: s, State: RefStateInvalid}
	}
	if strings.HasPrefix(s, QueryPrefix) {
		return &Reference{URL: nil, Value: s[len(QueryPrefix):], State: RefStateQuery}
	}
	if state, ok := localState(s); ok {
		if state == RefStateBased {
			s = s[1:]
		}
		u, err := url.Parse(s)
		if err == nil {
			return &Reference{URL: u, Value: s, State: state}
		}
	}
	u, err := url.Parse(s)
	if err != nil {
		return &Reference{URL: nil, Value: s, State: RefStateInvalid}
	}
	if !externalURL(u) {
		if _, err = id.Parse(u.Path); err == nil {
			return &Reference{URL: u, Value: s, State: RefStateZettel}
		}
		if u.Path == "" && u.Fragment != "" {
			return &Reference{URL: u, Value: s, State: RefStateSelf}
		}
	}
	return &Reference{URL: u, Value: s, State: RefStateExternal}
}

func invalidReference(s string) bool { return s == "" || s == "00000000000000" }
func externalURL(u *url.URL) bool {
	return u.Scheme != "" || u.Opaque != "" || u.Host != "" || u.User != nil
}

func localState(path string) (RefState, bool) {
	if len(path) > 0 && path[0] == '/' {
		if len(path) > 1 && path[1] == '/' {
			return RefStateBased, true
		}
		return RefStateHosted, true
	}
	if len(path) > 1 && path[0] == '.' {
		if len(path) > 2 && path[1] == '.' && path[2] == '/' {
			return RefStateHosted, true
		}
		return RefStateHosted, path[1] == '/'
	}
	return RefStateInvalid, false
}

// String returns the string representation of a reference.
func (r Reference) String() string {
	if r.URL != nil {
		return r.URL.String()
	}
	if r.State == RefStateQuery {
		return QueryPrefix + r.Value
	}
	return r.Value
}

// IsValid returns true if reference is valid
func (r *Reference) IsValid() bool { return r.State != RefStateInvalid }

// IsZettel returns true if it is a referencen to a local zettel.
func (r *Reference) IsZettel() bool {
	switch r.State {
	case RefStateZettel, RefStateSelf, RefStateFound, RefStateBroken:
		return true
	}
	return false
}

// IsLocal returns true if reference is local
func (r *Reference) IsLocal() bool {
	return r.State == RefStateHosted || r.State == RefStateBased
}

// IsExternal returns true if it is a referencen to external material.
func (r *Reference) IsExternal() bool { return r.State == RefStateExternal }

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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_test

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"},
		{",://", true, ""},
	}

	for i, tc := range testcases {
		got := ast.ParseReference(tc.link)
		if got.IsValid() == tc.err {
			t.Errorf(
				"TC=%d, expected parse error of %q: %v, but got %q", i, tc.link, tc.err, got)
		}
		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},
		{"00000000000000", false, false, false},
		{"http://zettelstore.de/z/ast", false, true, false},
		{"12345678901234", true, false, false},
		{"12345678901234#local", true, false, false},
		{"http://12345678901234", false, true, false},
		{"http://zettelstore.de/z/12345678901234", false, true, false},
		{"http://zettelstore.de/12345678901234", false, true, false},
		{"/12345678901234", false, false, true},
		{"//12345678901234", false, false, true},
		{"./12345678901234", false, false, true},
		{"../12345678901234", false, false, true},
		{".../12345678901234", false, true, false},
	}

	for i, tc := range testcases {
		ref := ast.ParseReference(tc.link)
		isZettel := ref.IsZettel()
		if isZettel != tc.isZettel {
			t.Errorf(
				"TC=%d, Reference %q isZettel=%v expected, but got %v",
				i,
				tc.link,
				tc.isZettel,
				isZettel)
		}
		isLocal := ref.IsLocal()
		if isLocal != tc.isLocal {
			t.Errorf(
				"TC=%d, Reference %q isLocal=%v expected, but got %v",
				i,
				tc.link,
				tc.isLocal, isLocal)
		}
		isExternal := ref.IsExternal()
		if isExternal != tc.isExternal {
			t.Errorf(
				"TC=%d, Reference %q isExternal=%v expected, but got %v",
				i,
				tc.link,
				tc.isExternal,
				isExternal)
		}
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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

// 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
	}

	// Implementation note:
	// It is much faster to use interface dispatching than to use a switch statement.
	// On my "cpu: Intel(R) Core(TM) i7-6820HQ CPU @ 2.70GHz", a switch statement
	// implementation tooks approx 940-980 ns/op. Interface dispatching is in the
	// range of 900-930 ns/op.
	node.WalkChildren(v)
	v.Visit(nil)
}

// 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)
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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_test

import (
	"testing"

	"zettelstore.de/client.fossil/attrs"
	"zettelstore.de/z/ast"
)

func BenchmarkWalk(b *testing.B) {
	root := ast.BlockSlice{
		&ast.HeadingNode{
			Inlines: ast.CreateInlineSliceFromWords("A", "Simple", "Heading"),
		},
		&ast.ParaNode{
			Inlines: ast.CreateInlineSliceFromWords("This", "is", "the", "introduction."),
		},
		&ast.NestedListNode{
			Kind: ast.NestedListUnordered,
			Items: []ast.ItemSlice{
				[]ast.ItemNode{
					&ast.ParaNode{
						Inlines: ast.CreateInlineSliceFromWords("Item", "1"),
					},
				},
				[]ast.ItemNode{
					&ast.ParaNode{
						Inlines: ast.CreateInlineSliceFromWords("Item", "2"),
					},
				},
			},
		},
		&ast.ParaNode{
			Inlines: ast.CreateInlineSliceFromWords("This", "is", "some", "intermediate", "text."),
		},
		ast.CreateParaNode(
			&ast.FormatNode{
				Kind: ast.FormatEmph,
				Attrs: attrs.Attributes(map[string]string{
					"":      "class",
					"color": "green",
				}),
				Inlines: ast.CreateInlineSliceFromWords("This", "is", "some", "emphasized", "text."),
			},
			&ast.SpaceNode{Lexeme: " "},
			&ast.LinkNode{
				Ref:     &ast.Reference{Value: "http://zettelstore.de"},
				Inlines: ast.CreateInlineSliceFromWords("URL", "text."),
			},
		),
	}
	v := benchVisitor{}
	b.ResetTimer()
	for n := 0; n < b.N; n++ {
		ast.Walk(&v, &root)
	}
}

type benchVisitor struct{}

func (bv *benchVisitor) Visit(ast.Node) ast.Visitor { return bv }

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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 auth provides services for authentification / authorization.
package auth

import (
	"time"

	"zettelstore.de/z/box"
	"zettelstore.de/z/config"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

// 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
}

// TokenManager provides methods to create authentication
type TokenManager interface {

	// GetToken produces a authentication token.
	GetToken(ident *meta.Meta, d time.Duration, kind TokenKind) ([]byte, error)

	// CheckToken checks the validity of the token and returns relevant data.
	CheckToken(token []byte, k TokenKind) (TokenData, error)
}

// TokenKind specifies for which application / usage a token is/was requested.
type TokenKind int

// Allowed values of token kind
const (
	_ TokenKind = iota
	KindAPI
	KindwebUI
)

// TokenData contains some important elements from a token.
type TokenData struct {
	Token   []byte
	Now     time.Time
	Issued  time.Time
	Expires time.Time
	Ident   string
	Zid     id.Zid
}

// AuthzManager provides methods for authorization.
type AuthzManager interface {
	BaseManager

	// Owner returns the zettel identifier of the owner.
	Owner() id.Zid

	// IsOwner returns true, if the given zettel identifier is that of the owner.
	IsOwner(zid id.Zid) bool

	// Returns true if authentication is enabled.
	WithAuth() bool

	// GetUserRole role returns the user role of the given user zettel.
	GetUserRole(user *meta.Meta) meta.UserRole
}

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

	BoxWithPolicy(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

	// User is allowed to read zettel
	CanRead(user, m *meta.Meta) bool

	// User is allowed to write zettel.
	CanWrite(user, oldMeta, newMeta *meta.Meta) bool

	// User is allowed to rename zettel
	CanRename(user, m *meta.Meta) bool

	// User is allowed to delete zettel.
	CanDelete(user, m *meta.Meta) bool

	// User is allowed to refresh box data.
	CanRefresh(user *meta.Meta) bool
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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 cred provides some function for handling credentials.
package cred

import (
	"bytes"

	"golang.org/x/crypto/bcrypt"
	"zettelstore.de/z/zettel/id"
)

// HashCredential returns a hashed vesion of the given credential
func HashCredential(zid id.Zid, ident, credential string) (string, error) {
	fullCredential := createFullCredential(zid, ident, credential)
	res, err := bcrypt.GenerateFromPassword(fullCredential, bcrypt.DefaultCost)
	if err != nil {
		return "", err
	}
	return string(res), nil
}

// CompareHashAndCredential checks, whether the hashed credential is a possible
// value when hashing the credential.
func CompareHashAndCredential(hashed string, zid id.Zid, ident, credential string) (bool, error) {
	fullCredential := createFullCredential(zid, ident, credential)
	err := bcrypt.CompareHashAndPassword([]byte(hashed), fullCredential)
	if err == nil {
		return true, nil
	}
	if err == bcrypt.ErrMismatchedHashAndPassword {
		return false, nil
	}
	return false, err
}

func createFullCredential(zid id.Zid, ident, credential string) []byte {
	var buf bytes.Buffer
	buf.WriteString(zid.String())
	buf.WriteByte(' ')
	buf.WriteString(ident)
	buf.WriteByte(' ')
	buf.WriteString(credential)
	return buf.Bytes()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2023-present 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 impl

import (
	"bytes"
	"crypto"
	"crypto/hmac"
	"encoding/base64"

	"zettelstore.de/sx.fossil"
	"zettelstore.de/sx.fossil/sxreader"
)

var encoding = base64.RawURLEncoding

const digestAlg = crypto.SHA384

func sign(claim sx.Object, secret []byte) ([]byte, error) {
	var buf bytes.Buffer
	sx.Print(&buf, claim)
	token := make([]byte, encoding.EncodedLen(buf.Len()))
	encoding.Encode(token, buf.Bytes())

	digest := hmac.New(digestAlg.New, secret)
	_, err := digest.Write(buf.Bytes())
	if err != nil {
		return nil, err
	}
	dig := digest.Sum(nil)
	encDig := make([]byte, encoding.EncodedLen(len(dig)))
	encoding.Encode(encDig, dig)

	token = append(token, '.')
	token = append(token, encDig...)
	return token, nil
}

func check(token []byte, secret []byte) (sx.Object, error) {
	i := bytes.IndexByte(token, '.')
	if i <= 0 || 1024 < i {
		return nil, ErrMalformedToken
	}
	buf := make([]byte, len(token))
	n, err := encoding.Decode(buf, token[:i])
	if err != nil {
		return nil, err
	}
	rdr := sxreader.MakeReader(bytes.NewReader(buf[:n]))
	obj, err := rdr.Read()
	if err != nil {
		return nil, err
	}

	var objBuf bytes.Buffer
	_, err = sx.Print(&objBuf, obj)
	if err != nil {
		return nil, err
	}

	digest := hmac.New(digestAlg.New, secret)
	_, err = digest.Write(objBuf.Bytes())
	if err != nil {
		return nil, err
	}

	n, err = encoding.Decode(buf, token[i+1:])
	if err != nil {
		return nil, err
	}
	if !hmac.Equal(buf[:n], digest.Sum(nil)) {
		return nil, ErrMalformedToken
	}
	return obj, nil
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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 impl provides services for authentification / authorization.
package impl

import (
	"errors"
	"hash/fnv"
	"io"
	"time"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/client.fossil/sexp"
	"zettelstore.de/sx.fossil"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/auth/policy"
	"zettelstore.de/z/box"
	"zettelstore.de/z/config"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

type myAuth struct {
	readonly bool
	owner    id.Zid
	secret   []byte
}

// New creates a new auth object.
func New(readonly bool, owner id.Zid, extSecret string) auth.Manager {
	return &myAuth{
		readonly: readonly,
		owner:    owner,
		secret:   calcSecret(extSecret),
	}
}

var configKeys = []string{
	kernel.CoreProgname,
	kernel.CoreGoVersion,
	kernel.CoreHostname,
	kernel.CoreGoOS,
	kernel.CoreGoArch,
	kernel.CoreVersion,
}

func calcSecret(extSecret string) []byte {
	h := fnv.New128()
	if extSecret != "" {
		io.WriteString(h, extSecret)
	}
	for _, key := range configKeys {
		io.WriteString(h, kernel.Main.GetConfig(kernel.CoreService, key).(string))
	}
	return h.Sum(nil)
}

// IsReadonly returns true, if the systems is configured to run in read-only-mode.
func (a *myAuth) IsReadonly() bool { return a.readonly }

// ErrMalformedToken signals a broken token.
var ErrMalformedToken = errors.New("auth: malformed token")

// ErrNoIdent signals that the 'ident' key is missing.
var ErrNoIdent = errors.New("auth: missing ident")

// ErrOtherKind signals that the token was defined for another token kind.
var ErrOtherKind = errors.New("auth: wrong token kind")

// ErrNoZid signals that the 'zid' key is missing.
var ErrNoZid = errors.New("auth: missing zettel id")

// GetToken returns a token to be used for authentification.
func (a *myAuth) GetToken(ident *meta.Meta, d time.Duration, kind auth.TokenKind) ([]byte, error) {
	subject, ok := ident.Get(api.KeyUserID)
	if !ok || subject == "" {
		return nil, ErrNoIdent
	}

	now := time.Now().Round(time.Second)
	sClaim := sx.MakeList(
		sx.Int64(kind),
		sx.MakeString(subject),
		sx.Int64(now.Unix()),
		sx.Int64(now.Add(d).Unix()),
		sx.Int64(ident.Zid),
	)
	return sign(sClaim, a.secret)
}

// ErrTokenExpired signals an exired token
var ErrTokenExpired = errors.New("auth: token expired")

// CheckToken checks the validity of the token and returns relevant data.
func (a *myAuth) CheckToken(tok []byte, k auth.TokenKind) (auth.TokenData, error) {
	var tokenData auth.TokenData

	obj, err := check(tok, a.secret)
	if err != nil {
		return tokenData, err
	}

	tokenData.Token = tok
	err = setupTokenData(obj, k, &tokenData)
	return tokenData, err
}

func setupTokenData(obj sx.Object, k auth.TokenKind, tokenData *auth.TokenData) error {
	vals, err := sexp.ParseList(obj, "isiii")
	if err != nil {
		return ErrMalformedToken
	}
	if auth.TokenKind(vals[0].(sx.Int64)) != k {
		return ErrOtherKind
	}
	ident := vals[1].(sx.String)
	if ident == "" {
		return ErrNoIdent
	}
	issued := time.Unix(int64(vals[2].(sx.Int64)), 0)
	expires := time.Unix(int64(vals[3].(sx.Int64)), 0)
	now := time.Now().Round(time.Second)
	if expires.Before(now) {
		return ErrTokenExpired
	}
	zid := id.Zid(vals[4].(sx.Int64))
	if !zid.IsValid() {
		return ErrNoZid
	}

	tokenData.Ident = ident.String()
	tokenData.Issued = issued
	tokenData.Now = now
	tokenData.Expires = expires
	tokenData.Zid = zid
	return nil
}

func (a *myAuth) Owner() id.Zid { return a.owner }

func (a *myAuth) IsOwner(zid id.Zid) bool {
	return zid.IsValid() && zid == a.owner
}

func (a *myAuth) WithAuth() bool { return a.owner != id.Invalid }

// GetUserRole role returns the user role of the given user zettel.
func (a *myAuth) GetUserRole(user *meta.Meta) meta.UserRole {
	if user == nil {
		if a.WithAuth() {
			return meta.UserRoleUnknown
		}
		return meta.UserRoleOwner
	}
	if a.IsOwner(user.Zid) {
		return meta.UserRoleOwner
	}
	if val, ok := user.Get(api.KeyUserRole); ok {
		if ur := meta.GetUserRole(val); ur != meta.UserRoleUnknown {
			return ur
		}
	}
	return meta.UserRoleReader
}

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

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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

import (
	"zettelstore.de/z/auth"
	"zettelstore.de/z/config"
	"zettelstore.de/z/zettel/meta"
)

type anonPolicy struct {
	authConfig config.AuthConfig
	pre        auth.Policy
}

func (ap *anonPolicy) CanCreate(user, newMeta *meta.Meta) bool {
	return ap.pre.CanCreate(user, newMeta)
}

func (ap *anonPolicy) CanRead(user, m *meta.Meta) bool {
	return ap.pre.CanRead(user, m) && ap.checkVisibility(m)
}

func (ap *anonPolicy) CanWrite(user, oldMeta, newMeta *meta.Meta) bool {
	return ap.pre.CanWrite(user, oldMeta, newMeta) && ap.checkVisibility(oldMeta)
}

func (ap *anonPolicy) CanRename(user, m *meta.Meta) bool {
	return ap.pre.CanRename(user, m) && ap.checkVisibility(m)
}

func (ap *anonPolicy) CanDelete(user, m *meta.Meta) bool {
	return ap.pre.CanDelete(user, m) && ap.checkVisibility(m)
}

func (ap *anonPolicy) CanRefresh(user *meta.Meta) bool {
	if ap.authConfig.GetExpertMode() || ap.authConfig.GetSimpleMode() {
		return true
	}
	return ap.pre.CanRefresh(user)
}

func (ap *anonPolicy) checkVisibility(m *meta.Meta) bool {
	if ap.authConfig.GetVisibility(m) == meta.VisibilityExpert {
		return ap.authConfig.GetExpertMode()
	}
	return true
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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

import (
	"context"

	"zettelstore.de/z/auth"
	"zettelstore.de/z/box"
	"zettelstore.de/z/config"
	"zettelstore.de/z/query"
	"zettelstore.de/z/web/server"
	"zettelstore.de/z/zettel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

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

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

// newBox creates a new policy box.
func newBox(box box.Box, policy auth.Policy) box.Box {
	return &polBox{
		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 zettel.Zettel) (id.Zid, error) {
	user := server.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) (zettel.Zettel, error) {
	z, err := pp.box.GetZettel(ctx, zid)
	if err != nil {
		return zettel.Zettel{}, err
	}
	user := server.GetUser(ctx)
	if pp.policy.CanRead(user, z.Meta) {
		return z, nil
	}
	return zettel.Zettel{}, box.NewErrNotAllowed("GetZettel", user, zid)
}

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

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

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 := server.GetUser(ctx)
	if pp.policy.CanRead(user, m) {
		return m, nil
	}
	return nil, box.NewErrNotAllowed("GetMeta", user, zid)
}

func (pp *polBox) SelectMeta(ctx context.Context, metaSeq []*meta.Meta, q *query.Query) ([]*meta.Meta, error) {
	user := server.GetUser(ctx)
	canRead := pp.policy.CanRead
	q = q.SetPreMatch(func(m *meta.Meta) bool { return canRead(user, m) })
	return pp.box.SelectMeta(ctx, metaSeq, q)
}

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

func (pp *polBox) UpdateZettel(ctx context.Context, zettel zettel.Zettel) error {
	zid := zettel.Meta.Zid
	user := server.GetUser(ctx)
	if !zid.IsValid() {
		return &box.ErrInvalidID{Zid: zid}
	}
	// Write existing zettel
	oldZettel, err := pp.box.GetZettel(ctx, zid)
	if err != nil {
		return err
	}
	if pp.policy.CanWrite(user, oldZettel.Meta, 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 {
	z, err := pp.box.GetZettel(ctx, curZid)
	if err != nil {
		return err
	}
	user := server.GetUser(ctx)
	if pp.policy.CanRename(user, z.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 {
	z, err := pp.box.GetZettel(ctx, zid)
	if err != nil {
		return err
	}
	user := server.GetUser(ctx)
	if pp.policy.CanDelete(user, z.Meta) {
		return pp.box.DeleteZettel(ctx, zid)
	}
	return box.NewErrNotAllowed("Delete", user, zid)
}

func (pp *polBox) Refresh(ctx context.Context) error {
	user := server.GetUser(ctx)
	if pp.policy.CanRefresh(user) {
		return pp.box.Refresh(ctx)
	}
	return box.NewErrNotAllowed("Refresh", user, id.Invalid)
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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

import (
	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/zettel/meta"
)

type defaultPolicy struct {
	manager auth.AuthzManager
}

func (*defaultPolicy) CanCreate(_, _ *meta.Meta) bool { return true }
func (*defaultPolicy) CanRead(_, _ *meta.Meta) bool   { return true }
func (d *defaultPolicy) CanWrite(user, oldMeta, _ *meta.Meta) bool {
	return d.canChange(user, oldMeta)
}
func (d *defaultPolicy) CanRename(user, m *meta.Meta) bool { return d.canChange(user, m) }
func (d *defaultPolicy) CanDelete(user, m *meta.Meta) bool { return d.canChange(user, m) }

func (*defaultPolicy) CanRefresh(user *meta.Meta) bool { return user != nil }

func (d *defaultPolicy) canChange(user, m *meta.Meta) bool {
	metaRo, ok := m.Get(api.KeyReadOnly)
	if !ok {
		return true
	}
	if user == nil {
		// If we are here, there is no authentication.
		// See owner.go:CanWrite.

		// No authentication: check for owner-like restriction, because the user
		// acts as an owner
		return metaRo != api.ValueUserRoleOwner && !meta.BoolValue(metaRo)
	}

	userRole := d.manager.GetUserRole(user)
	switch metaRo {
	case api.ValueUserRoleReader:
		return userRole > meta.UserRoleReader
	case api.ValueUserRoleWriter:
		return userRole > meta.UserRoleWriter
	case api.ValueUserRoleOwner:
		return userRole > meta.UserRoleOwner
	}
	return !meta.BoolValue(metaRo)
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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

import (
	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/config"
	"zettelstore.de/z/zettel/meta"
)

type ownerPolicy struct {
	manager    auth.AuthzManager
	authConfig config.AuthConfig
	pre        auth.Policy
}

func (o *ownerPolicy) CanCreate(user, newMeta *meta.Meta) bool {
	if user == nil || !o.pre.CanCreate(user, newMeta) {
		return false
	}
	return o.userIsOwner(user) || o.userCanCreate(user, newMeta)
}

func (o *ownerPolicy) userCanCreate(user, newMeta *meta.Meta) bool {
	if o.manager.GetUserRole(user) == meta.UserRoleReader {
		return false
	}
	if _, ok := newMeta.Get(api.KeyUserID); ok {
		return false
	}
	return true
}

func (o *ownerPolicy) CanRead(user, m *meta.Meta) bool {
	// No need to call o.pre.CanRead(user, meta), because it will always return true.
	// Both the default and the readonly policy allow to read a zettel.
	vis := o.authConfig.GetVisibility(m)
	if res, ok := o.checkVisibility(user, vis); ok {
		return res
	}
	return o.userIsOwner(user) || o.userCanRead(user, m, vis)
}

func (o *ownerPolicy) userCanRead(user, m *meta.Meta, vis meta.Visibility) bool {
	switch vis {
	case meta.VisibilityOwner, meta.VisibilityExpert:
		return false
	case meta.VisibilityPublic:
		return true
	}
	if user == nil {
		return false
	}
	if _, ok := m.Get(api.KeyUserID); ok {
		// 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{
	api.KeyID,
	api.KeyRole,
	api.KeyUserID,
	api.KeyUserRole,
}

func (o *ownerPolicy) CanWrite(user, oldMeta, newMeta *meta.Meta) bool {
	if user == nil || !o.pre.CanWrite(user, oldMeta, newMeta) {
		return false
	}
	vis := o.authConfig.GetVisibility(oldMeta)
	if res, ok := o.checkVisibility(user, vis); ok {
		return res
	}
	if o.userIsOwner(user) {
		return true
	}
	if !o.userCanRead(user, oldMeta, vis) {
		return false
	}
	if _, ok := oldMeta.Get(api.KeyUserID); ok {
		// Here we know, that user.Zid == newMeta.Zid (because of userCanRead) and
		// user.Zid == newMeta.Zid (because oldMeta.Zid == newMeta.Zid)
		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) {
		return false
	}
	if res, ok := o.checkVisibility(user, o.authConfig.GetVisibility(m)); ok {
		return res
	}
	return o.userIsOwner(user)
}

func (o *ownerPolicy) CanDelete(user, m *meta.Meta) bool {
	if user == nil || !o.pre.CanDelete(user, m) {
		return false
	}
	if res, ok := o.checkVisibility(user, o.authConfig.GetVisibility(m)); ok {
		return res
	}
	return o.userIsOwner(user)
}

func (o *ownerPolicy) CanRefresh(user *meta.Meta) bool {
	switch userRole := o.manager.GetUserRole(user); userRole {
	case meta.UserRoleUnknown:
		return o.authConfig.GetSimpleMode()
	case meta.UserRoleCreator:
		return o.authConfig.GetExpertMode() || o.authConfig.GetSimpleMode()
	}
	return true
}

func (o *ownerPolicy) checkVisibility(user *meta.Meta, vis meta.Visibility) (bool, bool) {
	if vis == meta.VisibilityExpert {
		return o.userIsOwner(user) && o.authConfig.GetExpertMode(), true
	}
	return false, false
}

func (o *ownerPolicy) userIsOwner(user *meta.Meta) bool {
	if user == nil {
		return false
	}
	if o.manager.IsOwner(user.Zid) {
		return true
	}
	if val, ok := user.Get(api.KeyUserRole); ok && val == api.ValueUserRoleOwner {
		return true
	}
	return false
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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 (
	"zettelstore.de/z/auth"
	"zettelstore.de/z/config"
	"zettelstore.de/z/zettel/meta"
)

// newPolicy creates a policy based on given constraints.
func newPolicy(manager auth.AuthzManager, authConfig config.AuthConfig) auth.Policy {
	var pol auth.Policy
	if manager.IsReadonly() {
		pol = &roPolicy{}
	} else {
		pol = &defaultPolicy{manager}
	}
	if manager.WithAuth() {
		pol = &ownerPolicy{
			manager:    manager,
			authConfig: authConfig,
			pre:        pol,
		}
	} else {
		pol = &anonPolicy{
			authConfig: authConfig,
			pre:        pol,
		}
	}
	return &prePolicy{pol}
}

type prePolicy struct {
	post auth.Policy
}

func (p *prePolicy) CanCreate(user, newMeta *meta.Meta) bool {
	return newMeta != nil && p.post.CanCreate(user, newMeta)
}

func (p *prePolicy) CanRead(user, m *meta.Meta) bool {
	return m != nil && p.post.CanRead(user, m)
}

func (p *prePolicy) CanWrite(user, oldMeta, newMeta *meta.Meta) bool {
	return oldMeta != nil && newMeta != nil && oldMeta.Zid == newMeta.Zid &&
		p.post.CanWrite(user, oldMeta, newMeta)
}

func (p *prePolicy) CanRename(user, m *meta.Meta) bool {
	return m != nil && p.post.CanRename(user, m)
}

func (p *prePolicy) CanDelete(user, m *meta.Meta) bool {
	return m != nil && p.post.CanDelete(user, m)
}

func (p *prePolicy) CanRefresh(user *meta.Meta) bool {
	return p.post.CanRefresh(user)
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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

import (
	"fmt"
	"testing"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

func TestPolicies(t *testing.T) {
	t.Parallel()
	testScene := []struct {
		readonly bool
		withAuth bool
		expert   bool
		simple   bool
	}{
		{true, true, true, true},
		{true, true, true, false},
		{true, true, false, true},
		{true, true, false, false},
		{true, false, true, true},
		{true, false, true, false},
		{true, false, false, true},
		{true, false, false, false},
		{false, true, true, true},
		{false, true, true, false},
		{false, true, false, true},
		{false, true, false, false},
		{false, false, true, true},
		{false, false, true, false},
		{false, false, false, true},
		{false, false, false, false},
	}
	for _, ts := range testScene {
		pol := newPolicy(
			&testAuthzManager{readOnly: ts.readonly, withAuth: ts.withAuth},
			&authConfig{simple: ts.simple, expert: ts.expert},
		)
		name := fmt.Sprintf("readonly=%v/withauth=%v/expert=%v/simple=%v",
			ts.readonly, ts.withAuth, ts.expert, ts.simple)
		t.Run(name, func(tt *testing.T) {
			testCreate(tt, pol, ts.withAuth, ts.readonly)
			testRead(tt, pol, ts.withAuth, ts.expert)
			testWrite(tt, pol, ts.withAuth, ts.readonly, ts.expert)
			testRename(tt, pol, ts.withAuth, ts.readonly, ts.expert)
			testDelete(tt, pol, ts.withAuth, ts.readonly, ts.expert)
			testRefresh(tt, pol, ts.withAuth, ts.expert, ts.simple)
		})
	}
}

type testAuthzManager struct {
	readOnly bool
	withAuth bool
}

func (a *testAuthzManager) IsReadonly() bool      { return a.readOnly }
func (*testAuthzManager) Owner() id.Zid           { return ownerZid }
func (*testAuthzManager) IsOwner(zid id.Zid) bool { return zid == ownerZid }

func (a *testAuthzManager) WithAuth() bool { return a.withAuth }

func (a *testAuthzManager) GetUserRole(user *meta.Meta) meta.UserRole {
	if user == nil {
		if a.WithAuth() {
			return meta.UserRoleUnknown
		}
		return meta.UserRoleOwner
	}
	if a.IsOwner(user.Zid) {
		return meta.UserRoleOwner
	}
	if val, ok := user.Get(api.KeyUserRole); ok {
		if ur := meta.GetUserRole(val); ur != meta.UserRoleUnknown {
			return ur
		}
	}
	return meta.UserRoleReader
}

type authConfig struct{ simple, expert bool }

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

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

func testCreate(t *testing.T, pol auth.Policy, withAuth, readonly 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) {
			got := pol.CanCreate(tc.user, tc.meta)
			if tc.exp != got {
				tt.Errorf("exp=%v, but got=%v", tc.exp, got)
			}
		})
	}
}

func testRead(t *testing.T, pol auth.Policy, withAuth, 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},
	}
	for _, tc := range testCases {
		t.Run("Read", func(tt *testing.T) {
			got := pol.CanRead(tc.user, tc.meta)
			if tc.exp != got {
				tt.Errorf("exp=%v, but got=%v", tc.exp, got)
			}
		})
	}
}

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()
	ownerZettel := newOwnerZettel()
	expertZettel := newExpertZettel()
	userZettel := newUserZettel()
	writerNew := writer.Clone()
	writerNew.Set(api.KeyUserRole, owner.GetDefault(api.KeyUserRole, ""))
	roFalse := newRoFalseZettel()
	roTrue := newRoTrueZettel()
	roReader := newRoReaderZettel()
	roWriter := newRoWriterZettel()
	roOwner := newRoOwnerZettel()
	notAuthNotReadonly := !withAuth && !readonly
	testCases := []struct {
		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) {
			got := pol.CanWrite(tc.user, tc.old, tc.new)
			if tc.exp != got {
				tt.Errorf("exp=%v, but got=%v", tc.exp, got)
			}
		})
	}
}

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()
	roTrue := newRoTrueZettel()
	roReader := newRoReaderZettel()
	roWriter := newRoWriterZettel()
	roOwner := newRoOwnerZettel()
	notAuthNotReadonly := !withAuth && !readonly
	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) {
			got := pol.CanRename(tc.user, tc.meta)
			if tc.exp != got {
				tt.Errorf("exp=%v, but got=%v", tc.exp, got)
			}
		})
	}
}

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()
	roTrue := newRoTrueZettel()
	roReader := newRoReaderZettel()
	roWriter := newRoWriterZettel()
	roOwner := newRoOwnerZettel()
	notAuthNotReadonly := !withAuth && !readonly
	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) {
			got := pol.CanDelete(tc.user, tc.meta)
			if tc.exp != got {
				tt.Errorf("exp=%v, but got=%v", tc.exp, got)
			}
		})
	}
}

func testRefresh(t *testing.T, pol auth.Policy, withAuth, expert, simple bool) {
	t.Helper()
	testCases := []struct {
		user *meta.Meta
		exp  bool
	}{
		{newAnon(), (!withAuth && expert) || simple},
		{newCreator(), !withAuth || expert || simple},
		{newReader(), true},
		{newWriter(), true},
		{newOwner(), true},
		{newOwner2(), true},
	}
	for _, tc := range testCases {
		t.Run("Refresh", func(tt *testing.T) {
			got := pol.CanRefresh(tc.user)
			if tc.exp != got {
				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(api.KeyTitle, "Creator")
	user.Set(api.KeyUserID, "ceator")
	user.Set(api.KeyUserRole, api.ValueUserRoleCreator)
	return user
}
func newReader() *meta.Meta {
	user := meta.New(readerZid)
	user.Set(api.KeyTitle, "Reader")
	user.Set(api.KeyUserID, "reader")
	user.Set(api.KeyUserRole, api.ValueUserRoleReader)
	return user
}
func newWriter() *meta.Meta {
	user := meta.New(writerZid)
	user.Set(api.KeyTitle, "Writer")
	user.Set(api.KeyUserID, "writer")
	user.Set(api.KeyUserRole, api.ValueUserRoleWriter)
	return user
}
func newOwner() *meta.Meta {
	user := meta.New(ownerZid)
	user.Set(api.KeyTitle, "Owner")
	user.Set(api.KeyUserID, "owner")
	user.Set(api.KeyUserRole, api.ValueUserRoleOwner)
	return user
}
func newOwner2() *meta.Meta {
	user := meta.New(owner2Zid)
	user.Set(api.KeyTitle, "Owner 2")
	user.Set(api.KeyUserID, "owner-2")
	user.Set(api.KeyUserRole, api.ValueUserRoleOwner)
	return user
}
func newZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(api.KeyTitle, "Any Zettel")
	return m
}
func newPublicZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(api.KeyTitle, "Public Zettel")
	m.Set(api.KeyVisibility, api.ValueVisibilityPublic)
	return m
}
func newCreatorZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(api.KeyTitle, "Creator Zettel")
	m.Set(api.KeyVisibility, api.ValueVisibilityCreator)
	return m
}
func newLoginZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(api.KeyTitle, "Login Zettel")
	m.Set(api.KeyVisibility, api.ValueVisibilityLogin)
	return m
}
func newOwnerZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(api.KeyTitle, "Owner Zettel")
	m.Set(api.KeyVisibility, api.ValueVisibilityOwner)
	return m
}
func newExpertZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(api.KeyTitle, "Expert Zettel")
	m.Set(api.KeyVisibility, api.ValueVisibilityExpert)
	return m
}
func newRoFalseZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(api.KeyTitle, "No r/o Zettel")
	m.Set(api.KeyReadOnly, api.ValueFalse)
	return m
}
func newRoTrueZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(api.KeyTitle, "A r/o Zettel")
	m.Set(api.KeyReadOnly, api.ValueTrue)
	return m
}
func newRoReaderZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(api.KeyTitle, "Reader r/o Zettel")
	m.Set(api.KeyReadOnly, api.ValueUserRoleReader)
	return m
}
func newRoWriterZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(api.KeyTitle, "Writer r/o Zettel")
	m.Set(api.KeyReadOnly, api.ValueUserRoleWriter)
	return m
}
func newRoOwnerZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(api.KeyTitle, "Owner r/o Zettel")
	m.Set(api.KeyReadOnly, api.ValueUserRoleOwner)
	return m
}
func newUserZettel() *meta.Meta {
	m := meta.New(userZid)
	m.Set(api.KeyTitle, "Any User")
	m.Set(api.KeyUserID, "any")
	return m
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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

import "zettelstore.de/z/zettel/meta"

type roPolicy struct{}

func (*roPolicy) CanCreate(_, _ *meta.Meta) bool   { return false }
func (*roPolicy) CanRead(_, _ *meta.Meta) bool     { return true }
func (*roPolicy) CanWrite(_, _, _ *meta.Meta) bool { return false }
func (*roPolicy) CanRename(_, _ *meta.Meta) bool   { return false }
func (*roPolicy) CanDelete(_, _ *meta.Meta) bool   { return false }
func (*roPolicy) CanRefresh(user *meta.Meta) bool  { return user != nil }

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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/client.fossil/api"
	"zettelstore.de/z/query"
	"zettelstore.de/z/zettel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

// 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 zettel.Zettel) (id.Zid, error)

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

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

	// UpdateZettel updates an existing zettel.
	UpdateZettel(ctx context.Context, zettel zettel.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
}

// ZidFunc is a function that processes identifier of a zettel.
type ZidFunc func(id.Zid)

// MetaFunc is a function that processes metadata of a zettel.
type MetaFunc func(*meta.Meta)

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

	// HasZettel returns true, if box conains zettel with given identifier.
	HasZettel(context.Context, id.Zid) bool

	// Apply identifier of every zettel to the given function, if predicate returns true.
	ApplyZid(context.Context, ZidFunc, query.RetrievePredicate) error

	// Apply metadata of every zettel to the given function, if predicate returns true.
	ApplyMeta(context.Context, MetaFunc, query.RetrievePredicate) 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
}

// StartState enumerates the possible states of starting and stopping a box.
//
// StartStateStopped -> StartStateStarting -> StartStateStarted -> StateStateStopping -> StartStateStopped.
//
// Other transitions are also possible.
type StartState uint8

// Constant values of StartState
const (
	StartStateStopped StartState = iota
	StartStateStarting
	StartStateStarted
	StartStateStopping
)

// StartStopper performs simple lifecycle management.
type StartStopper interface {
	// State the current status of the box.
	State() StartState

	// Start the box. Now all other functions of the box are allowed.
	// Starting a box, which is not in state StartStateStopped is not allowed.
	Start(ctx context.Context) error

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

// Refresher allow to refresh their internal data.
type Refresher interface {
	// Refresh the box data.
	Refresh(context.Context)
}

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

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

	// GetMeta returns the metadata of the zettel with the given identifier.
	GetMeta(context.Context, id.Zid) (*meta.Meta, error)

	// SelectMeta returns a list of metadata that comply to the given selection criteria.
	// If `metaSeq` is `nil`, the box assumes metadata of all available zettel.
	SelectMeta(ctx context.Context, metaSeq []*meta.Meta, q *query.Query) ([]*meta.Meta, error)

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

	// Refresh the data from the box and from its managed sub-boxes.
	Refresh(context.Context) 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
	OnReady               // Box is started and fully operational
	OnReload              // Box was reloaded
	OnZettel              // Something with a zettel happened
)

// UpdateInfo contains all the data about a changed zettel.
type UpdateInfo struct {
	Box    BaseBox
	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
}

// NoEnrichQuery provides a context that signals not to enrich, if the query does not need this.
func NoEnrichQuery(ctx context.Context, q *query.Query) context.Context {
	if q.EnrichNeeded() {
		return ctx
	}
	return NoEnrichContext(ctx)
}

// 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)
		}
		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, err.User.GetDefault(api.KeyUserID, "?"), err.User.Zid)
	}
	return fmt.Sprintf(
		"operation %q not allowed for user %v/%v",
		err.Op, err.User.GetDefault(api.KeyUserID, "?"), err.User.Zid)
}

// Is return true, if the error is of type ErrNotAllowed.
func (*ErrNotAllowed) Is(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")

// ErrCapacity is returned if a box has reached its capacity.
var ErrCapacity = errors.New("capacity exceeded")

// 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-present 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/client.fossil/api"
	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/query"
	"zettelstore.de/z/zettel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

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 {
	log      *logger.Logger
	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) []byte
}{
	id.MustParse(api.ZidVersion):              {genVersionBuildM, genVersionBuildC},
	id.MustParse(api.ZidHost):                 {genVersionHostM, genVersionHostC},
	id.MustParse(api.ZidOperatingSystem):      {genVersionOSM, genVersionOSC},
	id.MustParse(api.ZidLog):                  {genLogM, genLogC},
	id.MustParse(api.ZidBoxManager):           {genManagerM, genManagerC},
	id.MustParse(api.ZidMetadataKey):          {genKeysM, genKeysC},
	id.MustParse(api.ZidParser):               {genParserM, genParserC},
	id.MustParse(api.ZidStartupConfiguration): {genConfigZettelM, genConfigZettelC},
}

// Get returns the one program box.
func getCompBox(boxNumber int, mf box.Enricher) box.ManagedBox {
	return &compBox{
		log: kernel.Main.GetLogger(kernel.BoxService).Clone().
			Str("box", "comp").Int("boxnum", int64(boxNumber)).Child(),
		number:   boxNumber,
		enricher: mf,
	}
}

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

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

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

func (cb *compBox) CreateZettel(context.Context, zettel.Zettel) (id.Zid, error) {
	cb.log.Trace().Err(box.ErrReadOnly).Msg("CreateZettel")
	return id.Invalid, box.ErrReadOnly
}

func (cb *compBox) GetZettel(_ context.Context, zid id.Zid) (zettel.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 {
				cb.log.Trace().Msg("GetZettel/Content")
				return zettel.Zettel{
					Meta:    m,
					Content: zettel.NewContent(genContent(m)),
				}, nil
			}
			cb.log.Trace().Msg("GetZettel/NoContent")
			return zettel.Zettel{Meta: m}, nil
		}
	}
	cb.log.Trace().Err(box.ErrNotFound).Msg("GetZettel/Err")
	return zettel.Zettel{}, box.ErrNotFound
}

func (*compBox) HasZettel(_ context.Context, zid id.Zid) bool {
	_, found := myZettel[zid]
	return found
}

func (cb *compBox) ApplyZid(_ context.Context, handle box.ZidFunc, constraint query.RetrievePredicate) error {
	cb.log.Trace().Int("entries", int64(len(myZettel))).Msg("ApplyZid")
	for zid, gen := range myZettel {
		if !constraint(zid) {
			continue
		}
		if genMeta := gen.meta; genMeta != nil {
			if genMeta(zid) != nil {
				handle(zid)
			}
		}
	}
	return nil
}

func (cb *compBox) ApplyMeta(ctx context.Context, handle box.MetaFunc, constraint query.RetrievePredicate) error {
	cb.log.Trace().Int("entries", int64(len(myZettel))).Msg("ApplyMeta")
	for zid, gen := range myZettel {
		if !constraint(zid) {
			continue
		}
		if genMeta := gen.meta; genMeta != nil {
			if m := genMeta(zid); m != nil {
				updateMeta(m)
				cb.enricher.Enrich(ctx, m, cb.number)
				handle(m)
			}
		}
	}
	return nil
}

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

func (cb *compBox) UpdateZettel(context.Context, zettel.Zettel) error {
	cb.log.Trace().Err(box.ErrReadOnly).Msg("UpdateZettel")
	return box.ErrReadOnly
}

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

func (cb *compBox) RenameZettel(_ context.Context, curZid, _ id.Zid) error {
	err := box.ErrNotFound
	if _, ok := myZettel[curZid]; ok {
		err = box.ErrReadOnly
	}
	cb.log.Trace().Err(err).Msg("RenameZettel")
	return err
}

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

func (cb *compBox) DeleteZettel(_ context.Context, zid id.Zid) error {
	err := box.ErrNotFound
	if _, ok := myZettel[zid]; ok {
		err = box.ErrReadOnly
	}
	cb.log.Trace().Err(err).Msg("DeleteZettel")
	return err
}

func (cb *compBox) ReadStats(st *box.ManagedBoxStats) {
	st.ReadOnly = true
	st.Zettel = len(myZettel)
	cb.log.Trace().Int("zettel", int64(st.Zettel)).Msg("ReadStats")
}

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

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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

import (
	"bytes"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

func genConfigZettelM(zid id.Zid) *meta.Meta {
	if myConfig == nil {
		return nil
	}
	m := meta.New(zid)
	m.Set(api.KeyTitle, "Zettelstore Startup Configuration")
	m.Set(api.KeyCreated, kernel.Main.GetConfig(kernel.CoreService, kernel.CoreStarted).(string))
	m.Set(api.KeyVisibility, api.ValueVisibilityExpert)
	return m
}

func genConfigZettelC(*meta.Meta) []byte {
	var buf bytes.Buffer
	for i, p := range myConfig.Pairs() {
		if i > 0 {
			buf.WriteByte('\n')
		}
		buf.WriteString("; ''")
		buf.WriteString(p.Key)
		buf.WriteString("''")
		if p.Value != "" {
			buf.WriteString("\n: ``")
			for _, r := range p.Value {
				if r == '`' {
					buf.WriteByte('\\')
				}
				buf.WriteRune(r)
			}
			buf.WriteString("``")
		}
	}
	return buf.Bytes()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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

import (
	"bytes"
	"fmt"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

func genKeysM(zid id.Zid) *meta.Meta {
	m := meta.New(zid)
	m.Set(api.KeyTitle, "Zettelstore Supported Metadata Keys")
	m.Set(api.KeyCreated, kernel.Main.GetConfig(kernel.CoreService, kernel.CoreVTime).(string))
	m.Set(api.KeyVisibility, api.ValueVisibilityLogin)
	return m
}

func genKeysC(*meta.Meta) []byte {
	keys := meta.GetSortedKeyDescriptions()
	var buf bytes.Buffer
	buf.WriteString("|=Name<|=Type<|=Computed?:|=Property?:\n")
	for _, kd := range keys {
		fmt.Fprintf(&buf,
			"|[[%v|query:%v?]]|%v|%v|%v\n", kd.Name, kd.Name, kd.Type.Name, kd.IsComputed(), kd.IsProperty())
	}
	return buf.Bytes()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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

import (
	"bytes"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

func genLogM(zid id.Zid) *meta.Meta {
	m := meta.New(zid)
	m.Set(api.KeyTitle, "Zettelstore Log")
	m.Set(api.KeySyntax, meta.SyntaxText)
	m.Set(api.KeyCreated, kernel.Main.GetConfig(kernel.CoreService, kernel.CoreStarted).(string))
	m.Set(api.KeyModified, kernel.Main.GetLastLogTime().Local().Format(id.ZidLayout))
	return m
}

func genLogC(*meta.Meta) []byte {
	const tsFormat = "2006-01-02 15:04:05.999999"
	entries := kernel.Main.RetrieveLogEntries()
	var buf bytes.Buffer
	for _, entry := range entries {
		ts := entry.TS.Format(tsFormat)
		buf.WriteString(ts)
		for j := len(ts); j < len(tsFormat); j++ {
			buf.WriteByte('0')
		}
		buf.WriteByte(' ')
		buf.WriteString(entry.Level.Format())
		buf.WriteByte(' ')
		buf.WriteString(entry.Prefix)
		buf.WriteByte(' ')
		buf.WriteString(entry.Message)
		buf.WriteByte('\n')
	}
	return buf.Bytes()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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

import (
	"bytes"
	"fmt"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

func genManagerM(zid id.Zid) *meta.Meta {
	m := meta.New(zid)
	m.Set(api.KeyTitle, "Zettelstore Box Manager")
	m.Set(api.KeyCreated, kernel.Main.GetConfig(kernel.CoreService, kernel.CoreStarted).(string))
	return m
}

func genManagerC(*meta.Meta) []byte {
	kvl := kernel.Main.GetServiceStatistics(kernel.BoxService)
	if len(kvl) == 0 {
		return nil
	}
	var buf bytes.Buffer
	buf.WriteString("|=Name|=Value>\n")
	for _, kv := range kvl {
		fmt.Fprintf(&buf, "| %v | %v\n", kv.Key, kv.Value)
	}
	return buf.Bytes()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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

import (
	"bytes"
	"fmt"
	"sort"
	"strings"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

func genParserM(zid id.Zid) *meta.Meta {
	m := meta.New(zid)
	m.Set(api.KeyTitle, "Zettelstore Supported Parser")
	m.Set(api.KeyCreated, kernel.Main.GetConfig(kernel.CoreService, kernel.CoreVTime).(string))
	m.Set(api.KeyVisibility, api.ValueVisibilityLogin)
	return m
}

func genParserC(*meta.Meta) []byte {
	var buf bytes.Buffer
	buf.WriteString("|=Syntax<|=Alt. Value(s):|=Text Parser?:|=Text Format?:|=Image Format?:\n")
	syntaxes := parser.GetSyntaxes()
	sort.Strings(syntaxes)
	for _, syntax := range syntaxes {
		info := parser.Get(syntax)
		if info.Name != syntax {
			continue
		}
		altNames := info.AltNames
		sort.Strings(altNames)
		fmt.Fprintf(
			&buf, "|%v|%v|%v|%v|%v\n",
			syntax, strings.Join(altNames, ", "), info.IsASTParser, info.IsTextFormat, info.IsImageFormat)
	}
	return buf.Bytes()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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

import (
	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

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

func genVersionBuildM(zid id.Zid) *meta.Meta {
	m := getVersionMeta(zid, "Zettelstore Version")
	m.Set(api.KeyCreated, kernel.Main.GetConfig(kernel.CoreService, kernel.CoreVTime).(string))
	m.Set(api.KeyVisibility, api.ValueVisibilityLogin)
	return m
}
func genVersionBuildC(*meta.Meta) []byte {
	return []byte(kernel.Main.GetConfig(kernel.CoreService, kernel.CoreVersion).(string))
}

func genVersionHostM(zid id.Zid) *meta.Meta {
	m := getVersionMeta(zid, "Zettelstore Host")
	m.Set(api.KeyCreated, kernel.Main.GetConfig(kernel.CoreService, kernel.CoreStarted).(string))
	return m
}
func genVersionHostC(*meta.Meta) []byte {
	return []byte(kernel.Main.GetConfig(kernel.CoreService, kernel.CoreHostname).(string))
}

func genVersionOSM(zid id.Zid) *meta.Meta {
	m := getVersionMeta(zid, "Zettelstore Operating System")
	m.Set(api.KeyCreated, kernel.Main.GetConfig(kernel.CoreService, kernel.CoreStarted).(string))
	return m
}
func genVersionOSC(*meta.Meta) []byte {
	goOS := kernel.Main.GetConfig(kernel.CoreService, kernel.CoreGoOS).(string)
	goArch := kernel.Main.GetConfig(kernel.CoreService, kernel.CoreGoArch).(string)
	result := make([]byte, 0, len(goOS)+len(goArch)+1)
	result = append(result, goOS...)
	result = append(result, '/')
	return append(result, goArch...)
}

*,*::before,*::after {
    box-sizing: border-box;
  }
  html {
    font-size: 1rem;
    font-family: serif;
    scroll-behavior: smooth;
    height: 100%;
  }
  body {
    margin: 0;
    min-height: 100vh;
    line-height: 1.4;
    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 }
  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%;
  }
  thead>tr>td { border-bottom: 2px solid hsl(0, 0%, 70%); font-weight: bold }
  tfoot>tr>td { border-top: 2px solid hsl(0, 0%, 70%); font-weight: bold }
  td {
    text-align: left;
    padding: .25rem .5rem;
    border-bottom: 1px solid hsl(0, 0%, 85%)
  }
  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 }
  textarea {
    font-family: monospace;
    resize: vertical;
    width: 100%;
  }
  .zs-input {
    padding: .5em;
    display:block;
    border:none;
    border-bottom:1px solid #ccc;
    width:100%;
  }
  input.zs-primary { float:right }
  input.zs-secondary { float:left }
  input.zs-upload {
    padding-left: 1em;
    padding-right: 1em;
  }
  a:not([class]) { text-decoration-skip-ink: auto }
  a.broken { text-decoration: line-through }
  a.external::after { content: "➚"; display: inline-block }
  img { max-width: 100% }
  img.right { float: right }
  ol.zs-endnotes {
    padding-top: .5rem;
    border-top: 1px solid;
  }
  kbd { font-family:monospace }
  code,pre {
    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-info {
    background-color: lightblue;
    padding: .5rem 1rem;
  }
  .zs-warning {
    background-color: lightyellow;
    padding: .5rem 1rem;
  }
  .zs-error {
    background-color: lightpink;
    border-style: none !important;
    font-weight: bold;
  }
  td.left { text-align:left }
  td.center { text-align:center }
  td.right { text-align:right }
  .zs-font-size-0 { font-size:75% }
  .zs-font-size-1 { font-size:83% }
  .zs-font-size-2 { font-size:100% }
  .zs-font-size-3 { font-size:117% }
  .zs-font-size-4 { font-size:150% }
  .zs-font-size-5 { font-size:200% }
  .zs-deprecated { border-style: dashed; padding: .2rem }
  .zs-meta {
    font-size:.75rem;
    color:#444;
    margin-bottom:1rem;
  }
  .zs-meta a { color:#444 }
  h1+.zs-meta { margin-top:-1rem }
  nav > details { 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;
    }
  }

`(@@@@
(html ,@(if lang `((@ (lang ,lang))))
(head
  (meta (@ (charset "utf-8")))
  (meta (@ (name "viewport") (content "width=device-width, initial-scale=1.0")))
  (meta (@ (name "generator") (content "Zettelstore")))
  (meta (@ (name "format-detection") (content "telephone=no")))
  ,@META-HEADER
  (link (@ (rel "stylesheet") (href ,css-base-url)))
  (link (@ (rel "stylesheet") (href ,css-user-url)))
  ,@(if css-role-url `((link (@ (rel "stylesheet") (href ,css-role-url)))))
  (title ,title))
(body
  (nav (@ (class "zs-menu"))
    (a (@ (href ,home-url)) "Home")
    ,@(if with-auth
      `((div (@ (class "zs-dropdown"))
        (button "User")
        (nav (@ (class "zs-dropdown-content"))
          ,@(if user-is-valid
            `((a (@ (href ,user-zettel-url)) ,user-ident)
              (a (@ (href ,logout-url)) "Logout"))
            `((a (@ (href ,login-url)) "Login"))
          )
      )))
    )
    (div (@ (class "zs-dropdown"))
      (button "Lists")
      (nav (@ (class "zs-dropdown-content"))
        (a (@ (href ,list-zettel-url)) "List Zettel")
        (a (@ (href ,list-roles-url)) "List Roles")
        (a (@ (href ,list-tags-url)) "List Tags")
        ,@(if (bound? 'refresh-url) `((a (@ (href ,refresh-url)) "Refresh")))
    ))
    ,@(if new-zettel-links
      `((div (@ (class "zs-dropdown"))
        (button "New")
        (nav (@ (class "zs-dropdown-content"))
          ,@(map wui-link new-zettel-links)
       )))
    )
    (form (@ (action ,search-url))
      (input (@ (type "text") (placeholder "Search..") (name ,query-key-query))))
  )
  (main (@ (class "content")) ,DETAIL)
  ,@(if FOOTER `((footer (hr) ,@FOOTER)))
  ,@(if debug-mode '((div (b "WARNING: Debug mode is enabled. DO NOT USE IN PRODUCTION!"))))
)))

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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/client.fossil/api"
	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/query"
	"zettelstore.de/z/zettel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

func init() {
	manager.Register(
		" const",
		func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
			return &constBox{
				log: kernel.Main.GetLogger(kernel.BoxService).Clone().
					Str("box", "const").Int("boxnum", int64(cdata.Number)).Child(),
				number:   cdata.Number,
				zettel:   constZettelMap,
				enricher: cdata.Enricher,
			}, nil
		})
}

type constHeader map[string]string

type constZettel struct {
	header  constHeader
	content zettel.Content
}

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

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

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

func (cb *constBox) CreateZettel(context.Context, zettel.Zettel) (id.Zid, error) {
	cb.log.Trace().Err(box.ErrReadOnly).Msg("CreateZettel")
	return id.Invalid, box.ErrReadOnly
}

func (cb *constBox) GetZettel(_ context.Context, zid id.Zid) (zettel.Zettel, error) {
	if z, ok := cb.zettel[zid]; ok {
		cb.log.Trace().Msg("GetZettel")
		return zettel.Zettel{Meta: meta.NewWithData(zid, z.header), Content: z.content}, nil
	}
	cb.log.Trace().Err(box.ErrNotFound).Msg("GetZettel")
	return zettel.Zettel{}, box.ErrNotFound
}

func (cb *constBox) HasZettel(_ context.Context, zid id.Zid) bool {
	_, found := cb.zettel[zid]
	return found
}

func (cb *constBox) ApplyZid(_ context.Context, handle box.ZidFunc, constraint query.RetrievePredicate) error {
	cb.log.Trace().Int("entries", int64(len(cb.zettel))).Msg("ApplyZid")
	for zid := range cb.zettel {
		if constraint(zid) {
			handle(zid)
		}
	}
	return nil
}

func (cb *constBox) ApplyMeta(ctx context.Context, handle box.MetaFunc, constraint query.RetrievePredicate) error {
	cb.log.Trace().Int("entries", int64(len(cb.zettel))).Msg("ApplyMeta")
	for zid, zettel := range cb.zettel {
		if constraint(zid) {
			m := meta.NewWithData(zid, zettel.header)
			cb.enricher.Enrich(ctx, m, cb.number)
			handle(m)
		}
	}
	return nil
}

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

func (cb *constBox) UpdateZettel(context.Context, zettel.Zettel) error {
	cb.log.Trace().Err(box.ErrReadOnly).Msg("UpdateZettel")
	return box.ErrReadOnly
}

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

func (cb *constBox) RenameZettel(_ context.Context, curZid, _ id.Zid) error {
	err := box.ErrNotFound
	if _, ok := cb.zettel[curZid]; ok {
		err = box.ErrReadOnly
	}
	cb.log.Trace().Err(err).Msg("RenameZettel")
	return err
}

func (*constBox) CanDeleteZettel(context.Context, id.Zid) bool { return false }

func (cb *constBox) DeleteZettel(_ context.Context, zid id.Zid) error {
	err := box.ErrNotFound
	if _, ok := cb.zettel[zid]; ok {
		err = box.ErrReadOnly
	}
	cb.log.Trace().Err(err).Msg("DeleteZettel")
	return err
}

func (cb *constBox) ReadStats(st *box.ManagedBoxStats) {
	st.ReadOnly = true
	st.Zettel = len(cb.zettel)
	cb.log.Trace().Int("zettel", int64(st.Zettel)).Msg("ReadStats")
}

var constZettelMap = map[id.Zid]constZettel{
	id.ConfigurationZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Runtime Configuration",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxNone,
			api.KeyCreated:    "20200804111624",
			api.KeyVisibility: api.ValueVisibilityOwner,
		},
		zettel.NewContent(nil)},
	id.MustParse(api.ZidLicense): {
		constHeader{
			api.KeyTitle:      "Zettelstore License",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxText,
			api.KeyCreated:    "20210504135842",
			api.KeyLang:       api.ValueLangEN,
			api.KeyModified:   "20220131153422",
			api.KeyReadOnly:   api.ValueTrue,
			api.KeyVisibility: api.ValueVisibilityPublic,
		},
		zettel.NewContent(contentLicense)},
	id.MustParse(api.ZidAuthors): {
		constHeader{
			api.KeyTitle:      "Zettelstore Contributors",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxZmk,
			api.KeyCreated:    "20210504135842",
			api.KeyLang:       api.ValueLangEN,
			api.KeyReadOnly:   api.ValueTrue,
			api.KeyVisibility: api.ValueVisibilityLogin,
		},
		zettel.NewContent(contentContributors)},
	id.MustParse(api.ZidDependencies): {
		constHeader{
			api.KeyTitle:      "Zettelstore Dependencies",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxZmk,
			api.KeyLang:       api.ValueLangEN,
			api.KeyReadOnly:   api.ValueTrue,
			api.KeyVisibility: api.ValueVisibilityLogin,
			api.KeyCreated:    "20210504135842",
			api.KeyModified:   "20230601163100",
		},
		zettel.NewContent(contentDependencies)},
	id.BaseTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Base HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20230510155100",
			api.KeyModified:   "20230523144403",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentBaseSxn)},
	id.LoginTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Login Form HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20200804111624",
			api.KeyModified:   "20230527144100",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentLoginSxn)},
	id.ZettelTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Zettel HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20230510155300",
			api.KeyModified:   "20230523212800",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentZettelSxn)},
	id.InfoTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Info HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20200804111624",
			api.KeyModified:   "20230621131500",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentInfoSxn)},
	id.FormTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Form HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20200804111624",
			api.KeyModified:   "20230621132600",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentFormSxn)},
	id.RenameTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Rename Form HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20200804111624",
			api.KeyModified:   "20230707190246",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentRenameSxn)},
	id.DeleteTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Delete HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20200804111624",
			api.KeyModified:   "20230621133100",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentDeleteSxn)},
	id.ListTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore List Zettel HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20230704122100",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentListZettelSxn)},
	id.ErrorTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Error HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20210305133215",
			api.KeyModified:   "20230527224800",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentErrorSxn)},
	id.TemplateSxnZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Sxn Code for Templates",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20230619132800",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentTemplateCodeSxn)},
	id.MustParse(api.ZidBaseCSS): {
		constHeader{
			api.KeyTitle:      "Zettelstore Base CSS",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxCSS,
			api.KeyCreated:    "20200804111624",
			api.KeyVisibility: api.ValueVisibilityPublic,
		},
		zettel.NewContent(contentBaseCSS)},
	id.MustParse(api.ZidUserCSS): {
		constHeader{
			api.KeyTitle:      "Zettelstore User CSS",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxCSS,
			api.KeyCreated:    "20210622110143",
			api.KeyVisibility: api.ValueVisibilityPublic,
		},
		zettel.NewContent([]byte("/* User-defined CSS */"))},
	id.RoleCSSMapZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Role to CSS Map",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxNone,
			api.KeyCreated:    "20220321183214",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(nil)},
	id.EmojiZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Generic Emoji",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxGif,
			api.KeyReadOnly:   api.ValueTrue,
			api.KeyCreated:    "20210504175807",
			api.KeyVisibility: api.ValueVisibilityPublic,
		},
		zettel.NewContent(contentEmoji)},
	id.TOCNewTemplateZid: {
		constHeader{
			api.KeyTitle:      "New Menu",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxZmk,
			api.KeyLang:       api.ValueLangEN,
			api.KeyCreated:    "20210217161829",
			api.KeyVisibility: api.ValueVisibilityCreator,
		},
		zettel.NewContent(contentNewTOCZettel)},
	id.MustParse(api.ZidTemplateNewZettel): {
		constHeader{
			api.KeyTitle:      "New Zettel",
			api.KeyRole:       api.ValueRoleZettel,
			api.KeySyntax:     meta.SyntaxZmk,
			api.KeyCreated:    "20201028185209",
			api.KeyVisibility: api.ValueVisibilityCreator,
		},
		zettel.NewContent(nil)},
	id.MustParse(api.ZidTemplateNewUser): {
		constHeader{
			api.KeyTitle:                       "New User",
			api.KeyRole:                        api.ValueRoleConfiguration,
			api.KeySyntax:                      meta.SyntaxNone,
			api.KeyCreated:                     "20201028185209",
			meta.NewPrefix + api.KeyCredential: "",
			meta.NewPrefix + api.KeyUserID:     "",
			meta.NewPrefix + api.KeyUserRole:   api.ValueUserRoleReader,
			api.KeyVisibility:                  api.ValueVisibilityOwner,
		},
		zettel.NewContent(nil)},
	id.DefaultHomeZid: {
		constHeader{
			api.KeyTitle:   "Home",
			api.KeyRole:    api.ValueRoleZettel,
			api.KeySyntax:  meta.SyntaxZmk,
			api.KeyLang:    api.ValueLangEN,
			api.KeyCreated: "20210210190757",
		},
		zettel.NewContent(contentHomeZettel)},
}

//go:embed license.txt
var contentLicense []byte

//go:embed contributors.zettel
var contentContributors []byte

//go:embed dependencies.zettel
var contentDependencies []byte

//go:embed base.sxn
var contentBaseSxn []byte

//go:embed login.sxn
var contentLoginSxn []byte

//go:embed zettel.sxn
var contentZettelSxn []byte

//go:embed info.sxn
var contentInfoSxn []byte

//go:embed form.sxn
var contentFormSxn []byte

//go:embed rename.sxn
var contentRenameSxn []byte

//go:embed delete.sxn
var contentDeleteSxn []byte

//go:embed listzettel.sxn
var contentListZettelSxn []byte

//go:embed error.sxn
var contentErrorSxn []byte

//go:embed wuicode.sxn
var contentTemplateCodeSxn []byte

//go:embed base.css
var contentBaseCSS []byte

//go:embed emoji_spin.gif
var contentEmoji []byte

//go:embed newtoc.zettel
var contentNewTOCZettel []byte

//go:embed home.zettel
var contentHomeZettel []byte

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))
  (p "Do you really want to delete this zettel?")
  ,@(if shadowed-box
    `((div (@ (class "zs-info"))
      (h2 "Information")
      (p "If you delete this zettel, the previously shadowed zettel from overlayed box " ,shadowed-box " becomes available.")
    ))
  )
  ,@(if incoming
    `((div (@ (class "zs-warning"))
      (h2 "Warning!")
      (p "If you delete this zettel, incoming references from the following zettel will become invalid.")
      (ul ,@(map wui-item-link incoming))
    ))
  )
  ,@(if (and (bound? 'useless) useless)
    `((div (@ (class "zs-warning"))
      (h2 "Warning!")
      (p "Deleting this zettel will also delete the following files, so that they will not be interpreted as content for this zettel.")
      (ul ,@(map wui-item useless))
    ))
  )
  ,(wui-meta-desc metapairs)
  (form (@ (method "POST")) (input (@ (class "zs-primary") (type "submit") (value "Delete"))))
)

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 licenses.

=== 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.
```

=== ASCIIToSVG
; URL
: [[https://github.com/asciitosvg/asciitosvg]]
; License
: MIT
; Remarks
: ASCIIToSVG was incorporated into the source code of Zettelstore, moving it into package ''zettelstore.de/z/parser/draw''.
  Later, the source code was changed substantially to adapt it to the needs of Zettelstore.
```
Copyright (c) 2015 The ASCIIToSVG Contributors

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.
```

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

=== 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.
```

=== sx, zettelstore-client
These are companion projects, written by the current main developer of Zettelstore.
They are published under the same license, [[EUPL v1.2, or later|00000000000004]].

; URL & Source sx
: [[https://zettelstore.de/sx]]
; URL & Source zettelstore-client
: [[https://zettelstore.de/client/]]
; License:
: European Union Public License, version 1.2 (EUPL v1.2), or later.

`(article
  (header (h1 ,heading))
  ,message
)

`(article
  (header (h1 ,heading))
  (form (@ (action ,form-action-url) (method "POST") (enctype "multipart/form-data"))
  (div
    (label (@ (for "zs-title")) "Title " (a (@ (title "Main heading of this zettel.")) (@H "ⓘ")))
    (input (@ (class "zs-input") (type "text") (id "zs-title") (name "title") (placeholder "Title..") (value ,meta-title) (autofocus))))
  (div
    (label (@ (for "zs-role")) "Role " (a (@ (title "One word, without spaces, to set the main role of this zettel.")) (@H "ⓘ")))
    (input (@ (class "zs-input") (type "text") (id "zs-role") (name "role") (placeholder "role..") (value ,meta-role)
      ,@(if role-data '((list "zs-role-data")))
    ))
    ,@(wui-datalist "zs-role-data" role-data)
  )
  (div
    (label (@ (for "zs-tags")) "Tags " (a (@ (title "Tags must begin with an '#' sign. They are separated by spaces.")) (@H "ⓘ")))
    (input (@ (class "zs-input") (type "text") (id "zs-tags") (name "tags") (placeholder "#tag") (value ,meta-tags))))
  (div
    (label (@ (for "zs-meta")) "Metadata " (a (@ (title "Other metadata for this zettel. Each line contains a key/value pair, separated by a colon ':'.")) (@H "ⓘ")))
    (textarea (@ (class "zs-input") (id "zs-meta") (name "meta") (rows "4") (placeholder "metakey: metavalue")) ,meta))
  (div
    (label (@ (for "zs-syntax")) "Syntax " (a (@ (title "Syntax of zettel content below, one word. Typically 'zmk' (for zettelmarkup).")) (@H "ⓘ")))
    (input (@ (class "zs-input") (type "text") (id "zs-syntax") (name "syntax") (placeholder "syntax..") (value ,meta-syntax)
      ,@(if syntax-data '((list "zs-syntax-data")))
    ))
    ,@(wui-datalist "zs-syntax-data" syntax-data)
  )
  ,@(if (bound? 'content)
    `((div
      (label (@ (for "zs-content")) "Content " (a (@ (title "Content for this zettel, according to above syntax.")) (@H "ⓘ")))
      (textarea (@ (class "zs-input zs-content") (id "zs-content") (name "content") (rows "20") (placeholder "Zettel content..")) ,content)
    ))
  )
  (div
    (input (@ (class "zs-primary") (type "submit") (value "Submit")))
    (input (@ (class "zs-secondary") (type "submit") (value "Save") (formaction "?save")))
    (input (@ (class "zs-upload") (type "file") (id "zs-file") (name "file")))
  ))
)

=== 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.

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]]: {{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)
    (p
      (a (@ (href ,web-url)) "Web")
      (@H " · ") (a (@ (href ,context-url)) "Context")
      ,@(if (bound? 'edit-url) `((@H " · ") (a (@ (href ,edit-url)) "Edit")))
      ,@(if (bound? 'copy-url) `((@H " · ") (a (@ (href ,copy-url)) "Copy")))
      ,@(if (bound? 'version-url) `((@H " · ") (a (@ (href ,version-url)) "Version")))
      ,@(if (bound? 'child-url) `((@H " · ") (a (@ (href ,child-url)) "Child")))
      ,@(if (bound? 'folge-url) `((@H " · ") (a (@ (href ,folge-url)) "Folge")))
      ,@(if (bound? 'rename-url) `((@H " · ") (a (@ (href ,rename-url)) "Rename")))
      ,@(if (bound? 'delete-url) `((@H " · ") (a (@ (href ,delete-url)) "Delete")))
    )
  )
  (h2 "Interpreted Metadata")
  (table ,@(map wui-table-row metadata))
  (h2 "References")
  ,@(if local-links `((h3 "Local")    (ul ,@(map wui-valid-link local-links))))
  ,@(if query-links `((h3 "Queries")  (ul ,@(map wui-item-link query-links))))
  ,@(if ext-links   `((h3 "External") (ul ,@(map wui-item-popup-link ext-links))))
  (h3 "Unlinked")
  ,@unlinked-content
  (form
    (label (@ (for "phrase")) "Search Phrase")
    (input (@ (class "zs-input") (type "text") (id "phrase") (name ,query-key-phrase) (placeholder "Phrase..") (value ,phrase)))
  )
  (h2 "Parts and encodings")
  ,(wui-enc-matrix enc-eval)
  (h3 "Parsed (not evaluated)")
  ,(wui-enc-matrix enc-parsed)
  ,@(if shadow-links
    `((h2 "Shadowed Boxes")
      (ul ,@(map wui-item shadow-links))
    )
  )
)

Copyright (c) 2020-present 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

This European Union Public Licence (the ‘EUPL’) applies to the Work (as defined
below) which is provided under the terms of this Licence. Any use of the Work,
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use is covered by a right of the copyright holder of the Work).

The Work is provided under the terms of this Licence when the Licensor (as
defined below) has placed the following notice immediately following the
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                          Licensed under the EUPL

or has expressed by any other means his willingness to license under the EUPL.

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unless the Original Work is expressly distributed only under this version of
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Compatibility clause: If the Licensee Distributes or Communicates Derivative
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— any litigation resulting from the interpretation of this License, arising
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— this Licence shall be governed by the law of the European Union Member State
  where the Licensor has his seat, resides or has his registered office,
— this licence shall be governed by Belgian law if the Licensor has no seat,
  residence or registered office inside a European Union Member State.


                                  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.

`(article
  (header (h1 ,heading))
  (form (@ (action ,search-url))
    (input (@ (class "zs-input") (type "text") (placeholder "Search..") (name ,query-key-query) (value ,query-value))))
  ,@content
  ,@endnotes
  (form (@ (action ,(if (bound? 'create-url) create-url)))
      "Other encodings: "
      (a (@ (href ,data-url)) "data")
      ", "
      (a (@ (href ,plain-url)) "plain")
      ,@(if (bound? 'create-url)
        `((input (@ (type "hidden") (name ,query-key-query) (value ,query-value)))
          (input (@ (type "hidden") (name ,query-key-seed) (value ,seed)))
          (input (@ (class "zs-primary") (type "submit") (value "Save As Zettel")))
        )
      )
  )
)

`(article
  (header (h1 "Login"))
  ,@(if retry '((div (@ (class "zs-indication zs-error")) "Wrong user name / password. Try again.")))
  (form (@ (method "POST") (action ""))
    (div
      (label (@ (for "username")) "User name:")
      (input (@ (class "zs-input") (type "text") (id "username") (name "username") (placeholder "Your user name..") (autofocus))))
    (div
      (label (@ (for "password")) "Password:")
      (input (@ (class "zs-input") (type "password") (id "password") (name "password") (placeholder "Your password.."))))
    (div
      (input (@ (class "zs-primary") (type "submit") (value "Login"))))
  )
)

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))
  (p "Do you really want to rename this zettel?")
  ,@(if incoming
    `((div (@ (class "zs-warning"))
      (h2 "Warning!")
      (p "If you rename this zettel, incoming references from the following zettel will become invalid.")
      (ul ,@(map wui-item-link incoming))
    ))
  )
  ,@(if (and (bound? 'useless) useless)
    `((div (@ (class "zs-warning"))
      (h2 "Warning!")
      (p "Renaming this zettel will also delete the following files, so that they will not be interpreted as content for this zettel.")
      (ul ,@(map wui-item useless))
    ))
  )
  (form (@ (method "POST"))
    (input (@ (type "hidden") (id "curzid") (name "curzid") (value ,zid)))
    (div
      (label (@ (for "newzid")) "New zettel id")
      (input (@ (class "zs-input") (type "text") (id "newzid") (name "newzid") (placeholder "ZID..") (value ,zid) (autofocus))))
    (div (input (@ (class "zs-primary") (type "submit") (value "Rename"))))
  )
  ,(wui-meta-desc metapairs)
)

;;;----------------------------------------------------------------------------
;;; Copyright (c) 2023-present 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.
;;;----------------------------------------------------------------------------

;; wui-list-item returns the argument as a HTML list item.
(define (wui-item s) `(li ,s))

;; wui-table-row takes a pair and translates it into a HTML table row with
;; two columns.
(define (wui-table-row p)
    `(tr (td ,(car p)) (td ,(cdr p))))

;; wui-valid-link translates a local link into a HTML link. A link is a pair
;; (valid . url). If valid is not truish, only the invalid url is returned.
(define (wui-valid-link l)
    (if (car l)
        `(li (a (@ (href ,(cdr l))) ,(cdr l)))
        `(li ,(cdr l))))

;; wui-link taks an url and returns a HTML link inside.
(define (wui-link q)
    `(a (@ (href ,(cdr q))) ,(car q)))

;; wui-item-link taks a pair (text . url) and returns a HTML link inside
;; a list item.
(define (wui-item-link q) `(li ,(wui-link q)))

;; wui-tdata-link taks a pair (text . url) and returns a HTML link inside
;; a table data item.
(define (wui-tdata-link q) `(td ,(wui-link q)))

;; wui-item-popup-link is like 'wui-item-link, but the HTML link will open
;; a new tab / window.
(define (wui-item-popup-link e)
    `(li (a (@ (href ,e) (target "_blank") (rel "noopener noreferrer")) ,e)))

;; wui-option-value returns a value for an HTML option element.
(define (wui-option-value v) `(option (@ (value ,v))))

;; wui-datalist returns a HTML datalist with the given HTML identifier and a
;; list of values.
(define (wui-datalist id lst)
    (if lst
        `((datalist (@ (id ,id)) ,@(map wui-option-value lst)))))

;; wui-pair-desc-item takes a pair '(term . text) and returns a list with
;; a HTML description term and a HTML description data. 
(define (wui-pair-desc-item p) `((dt ,(car p)) (dd ,(cdr p))))

;; wui-meta-desc returns a HTML description list made from the list of pairs
;; given.
(define (wui-meta-desc l)
    `(dl ,@(apply append (map wui-pair-desc-item l))))

;; wui-enc-matrix returns the HTML table of all encodings and parts.
(define (wui-enc-matrix matrix)
    `(table
      ,@(map
         (lambda (row) `(tr (th ,(car row)) ,@(map wui-tdata-link (cdr row))))
         matrix)))

`(article
  (header
    (h1 ,heading)
    (div (@ (class "zs-meta"))
      ,@(if (bound? 'edit-url) `((a (@ (href ,edit-url)) "Edit") (@H " · ")))
      ,zid (@H " · ")
      (a (@ (href ,info-url)) "Info") (@H " · ")
      "(" ,@(if (bound? 'role-url) `((a (@ (href ,role-url)) ,meta-role)))
          ,@(if (and (bound? 'folge-role-url) (bound? 'meta-folge-role))
                `((@H " → ") (a (@ (href ,folge-role-url)) ,meta-folge-role)))
      ")"
      ,@(if tag-refs `((@H " · ") ,@tag-refs))
      ,@(if (bound? 'copy-url) `((@H " · ") (a (@ (href ,copy-url)) "Copy")))
      ,@(if (bound? 'version-url) `((@H " · ") (a (@ (href ,version-url)) "Version")))
      ,@(if (bound? 'child-url) `((@H " · ") (a (@ (href ,child-url)) "Child")))
      ,@(if (bound? 'folge-url) `((@H " · ") (a (@ (href ,folge-url)) "Folge")))
      ,@(if predecessor-refs `((br) "Predecessor: " ,predecessor-refs))
      ,@(if precursor-refs `((br) "Precursor: " ,precursor-refs))
      ,@(if superior-refs `((br) "Superior: " ,superior-refs))
      ,@(if (bound? 'meta-url) `((br) "URL: " ,(url-to-html meta-url)))
      ,@(let (author (and (bound? 'meta-author) meta-author)) (if author `((br) "By " ,author)))
    )
  )
  ,@content
  ,endnotes
  ,@(if (or folge-links subordinate-links back-links successor-links)
    `((nav
      ,@(if folge-links `((details (@ (open)) (summary "Folgezettel") (ul ,@(map wui-item-link folge-links)))))
      ,@(if subordinate-links `((details (@ (open)) (summary "Subordinates") (ul ,@(map wui-item-link subordinate-links)))))
      ,@(if back-links `((details (@ (open)) (summary "Incoming") (ul ,@(map wui-item-link back-links)))))
      ,@(if successor-links `((details (@ (open)) (summary "Successors") (ul ,@(map wui-item-link successor-links)))))
     ))
  )
)

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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"
	"sync"

	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager"
	"zettelstore.de/z/box/notify"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/query"
	"zettelstore.de/z/zettel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

func init() {
	manager.Register("dir", func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
		var log *logger.Logger
		if krnl := kernel.Main; krnl != nil {
			log = krnl.GetLogger(kernel.BoxService).Clone().Str("box", "dir").Int("boxnum", int64(cdata.Number)).Child()
		}
		path := getDirPath(u)
		if _, err := os.Stat(path); errors.Is(err, os.ErrNotExist) {
			return nil, err
		}
		dp := dirBox{
			log:        log,
			number:     cdata.Number,
			location:   u.String(),
			readonly:   box.GetQueryBool(u, "readonly"),
			cdata:      *cdata,
			dir:        path,
			notifySpec: getDirSrvInfo(log, u.Query().Get("type")),
			fSrvs:      makePrime(uint32(box.GetQueryInt(u, "worker", 1, 7, 1499))),
		}
		return &dp, nil
	})
}

func makePrime(n uint32) uint32 {
	for !isPrime(n) {
		n++
	}
	return n
}

func isPrime(n uint32) bool {
	if n == 0 {
		return false
	}
	if n <= 3 {
		return true
	}
	if n%2 == 0 {
		return false
	}
	for i := uint32(3); i*i <= n; i += 2 {
		if n%i == 0 {
			return false
		}
	}
	return true
}

type notifyTypeSpec int

const (
	_ notifyTypeSpec = iota
	dirNotifyAny
	dirNotifySimple
	dirNotifyFS
)

func getDirSrvInfo(log *logger.Logger, notifyType string) notifyTypeSpec {
	for count := 0; count < 2; count++ {
		switch notifyType {
		case kernel.BoxDirTypeNotify:
			return dirNotifyFS
		case kernel.BoxDirTypeSimple:
			return dirNotifySimple
		default:
			notifyType = kernel.Main.GetConfig(kernel.BoxService, kernel.BoxDefaultDirType).(string)
		}
	}
	log.Error().Str("notifyType", notifyType).Msg("Unable to set notify type, using a default")
	return dirNotifySimple
}

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

// dirBox uses a directory to store zettel as files.
type dirBox struct {
	log        *logger.Logger
	number     int
	location   string
	readonly   bool
	cdata      manager.ConnectData
	dir        string
	notifySpec notifyTypeSpec
	dirSrv     *notify.DirService
	fSrvs      uint32
	fCmds      []chan fileCmd
	mxCmds     sync.RWMutex
}

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

func (dp *dirBox) State() box.StartState {
	if ds := dp.dirSrv; ds != nil {
		switch ds.State() {
		case notify.DsCreated:
			return box.StartStateStopped
		case notify.DsStarting:
			return box.StartStateStarting
		case notify.DsWorking:
			return box.StartStateStarted
		case notify.DsMissing:
			return box.StartStateStarted
		case notify.DsStopping:
			return box.StartStateStopping
		}
	}
	return box.StartStateStopped
}

func (dp *dirBox) Start(context.Context) error {
	dp.mxCmds.Lock()
	defer dp.mxCmds.Unlock()
	dp.fCmds = make([]chan fileCmd, 0, dp.fSrvs)
	for i := uint32(0); i < dp.fSrvs; i++ {
		cc := make(chan fileCmd)
		go fileService(i, dp.log.Clone().Str("sub", "file").Uint("fn", uint64(i)).Child(), dp.dir, cc)
		dp.fCmds = append(dp.fCmds, cc)
	}

	var notifier notify.Notifier
	var err error
	switch dp.notifySpec {
	case dirNotifySimple:
		notifier, err = notify.NewSimpleDirNotifier(dp.log.Clone().Str("notify", "simple").Child(), dp.dir)
	default:
		notifier, err = notify.NewFSDirNotifier(dp.log.Clone().Str("notify", "fs").Child(), dp.dir)
	}
	if err != nil {
		dp.log.Fatal().Err(err).Msg("Unable to create directory supervisor")
		dp.stopFileServices()
		return err
	}
	dp.dirSrv = notify.NewDirService(
		dp,
		dp.log.Clone().Str("sub", "dirsrv").Child(),
		notifier,
		dp.cdata.Notify,
	)
	dp.dirSrv.Start()
	return nil
}

func (dp *dirBox) Refresh(_ context.Context) {
	dp.dirSrv.Refresh()
	dp.log.Trace().Msg("Refresh")
}

func (dp *dirBox) Stop(_ context.Context) {
	dirSrv := dp.dirSrv
	dp.dirSrv = nil
	if dirSrv != nil {
		dirSrv.Stop()
	}
	dp.stopFileServices()
}

func (dp *dirBox) stopFileServices() {
	for _, c := range dp.fCmds {
		close(c)
	}
}

func (dp *dirBox) notifyChanged(zid id.Zid) {
	if chci := dp.cdata.Notify; chci != nil {
		dp.log.Trace().Zid(zid).Msg("notifyChanged")
		chci <- box.UpdateInfo{Reason: box.OnZettel, 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(_ context.Context) bool {
	return !dp.readonly
}

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

	newZid, err := dp.dirSrv.SetNewDirEntry()
	if err != nil {
		return id.Invalid, err
	}
	meta := zettel.Meta
	meta.Zid = newZid
	entry := notify.DirEntry{Zid: newZid}
	dp.updateEntryFromMetaContent(&entry, meta, zettel.Content)

	err = dp.srvSetZettel(ctx, &entry, zettel)
	if err == nil {
		err = dp.dirSrv.UpdateDirEntry(&entry)
	}
	dp.notifyChanged(meta.Zid)
	dp.log.Trace().Err(err).Zid(meta.Zid).Msg("CreateZettel")
	return meta.Zid, err
}

func (dp *dirBox) GetZettel(ctx context.Context, zid id.Zid) (zettel.Zettel, error) {
	entry := dp.dirSrv.GetDirEntry(zid)
	if !entry.IsValid() {
		return zettel.Zettel{}, box.ErrNotFound
	}
	m, c, err := dp.srvGetMetaContent(ctx, entry, zid)
	if err != nil {
		return zettel.Zettel{}, err
	}
	zettel := zettel.Zettel{Meta: m, Content: zettel.NewContent(c)}
	dp.log.Trace().Zid(zid).Msg("GetZettel")
	return zettel, nil
}

func (dp *dirBox) HasZettel(_ context.Context, zid id.Zid) bool {
	return dp.dirSrv.GetDirEntry(zid).IsValid()
}

func (dp *dirBox) ApplyZid(_ context.Context, handle box.ZidFunc, constraint query.RetrievePredicate) error {
	entries := dp.dirSrv.GetDirEntries(constraint)
	dp.log.Trace().Int("entries", int64(len(entries))).Msg("ApplyZid")
	for _, entry := range entries {
		handle(entry.Zid)
	}
	return nil
}

func (dp *dirBox) ApplyMeta(ctx context.Context, handle box.MetaFunc, constraint query.RetrievePredicate) error {
	entries := dp.dirSrv.GetDirEntries(constraint)
	dp.log.Trace().Int("entries", int64(len(entries))).Msg("ApplyMeta")

	// The following loop could be parallelized if needed for performance.
	for _, entry := range entries {
		m, err := dp.srvGetMeta(ctx, entry, entry.Zid)
		if err != nil {
			dp.log.Trace().Err(err).Msg("ApplyMeta/getMeta")
			return err
		}
		dp.cdata.Enricher.Enrich(ctx, m, dp.number)
		handle(m)
	}
	return nil
}

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

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

	meta := zettel.Meta
	zid := meta.Zid
	if !zid.IsValid() {
		return &box.ErrInvalidID{Zid: zid}
	}
	entry := dp.dirSrv.GetDirEntry(zid)
	if !entry.IsValid() {
		// Existing zettel, but new in this box.
		entry = &notify.DirEntry{Zid: zid}
	}
	dp.updateEntryFromMetaContent(entry, meta, zettel.Content)
	dp.dirSrv.UpdateDirEntry(entry)
	err := dp.srvSetZettel(ctx, entry, zettel)
	if err == nil {
		dp.notifyChanged(zid)
	}
	dp.log.Trace().Zid(zid).Err(err).Msg("UpdateZettel")
	return err
}

func (dp *dirBox) updateEntryFromMetaContent(entry *notify.DirEntry, m *meta.Meta, content zettel.Content) {
	entry.SetupFromMetaContent(m, content, dp.cdata.Config.GetZettelFileSyntax)
}

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

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

	// Check whether zettel with new ID already exists in this box.
	if dp.HasZettel(ctx, newZid) {
		return &box.ErrInvalidID{Zid: newZid}
	}

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

	newEntry, err := dp.dirSrv.RenameDirEntry(curEntry, newZid)
	if err != nil {
		return err
	}
	oldMeta.Zid = newZid
	newZettel := zettel.Zettel{Meta: oldMeta, Content: zettel.NewContent(oldContent)}
	if err = dp.srvSetZettel(ctx, &newEntry, newZettel); err != nil {
		// "Rollback" rename. No error checking...
		dp.dirSrv.RenameDirEntry(&newEntry, curZid)
		return err
	}
	err = dp.srvDeleteZettel(ctx, curEntry, curZid)
	if err == nil {
		dp.notifyChanged(curZid)
		dp.notifyChanged(newZid)
	}
	dp.log.Trace().Zid(curZid).Zid(newZid).Err(err).Msg("RenameZettel")
	return err
}

func (dp *dirBox) CanDeleteZettel(_ context.Context, zid id.Zid) bool {
	if dp.readonly {
		return false
	}
	entry := dp.dirSrv.GetDirEntry(zid)
	return entry.IsValid()
}

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

	entry := dp.dirSrv.GetDirEntry(zid)
	if !entry.IsValid() {
		return box.ErrNotFound
	}
	err := dp.dirSrv.DeleteDirEntry(zid)
	if err != nil {
		return nil
	}
	err = dp.srvDeleteZettel(ctx, entry, zid)
	if err == nil {
		dp.notifyChanged(zid)
	}
	dp.log.Trace().Zid(zid).Err(err).Msg("DeleteZettel")
	return err
}

func (dp *dirBox) ReadStats(st *box.ManagedBoxStats) {
	st.ReadOnly = dp.readonly
	st.Zettel = dp.dirSrv.NumDirEntries()
	dp.log.Trace().Int("zettel", int64(st.Zettel)).Msg("ReadStats")
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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

import "testing"

func TestIsPrime(t *testing.T) {
	testcases := []struct {
		n   uint32
		exp bool
	}{
		{0, false}, {1, true}, {2, true}, {3, true}, {4, false}, {5, true},
		{6, false}, {7, true}, {8, false}, {9, false}, {10, false},
		{11, true}, {12, false}, {13, true}, {14, false}, {15, false},
		{17, true}, {19, true}, {21, false}, {23, true}, {25, false},
		{27, false}, {29, true}, {31, true}, {33, false}, {35, false},
	}
	for _, tc := range testcases {
		got := isPrime(tc.n)
		if got != tc.exp {
			t.Errorf("isPrime(%d)=%v, but got %v", tc.n, tc.exp, got)
		}
	}
}

func TestMakePrime(t *testing.T) {
	for i := uint32(0); i < 1500; i++ {
		np := makePrime(i)
		if np < i {
			t.Errorf("makePrime(%d) < %d", i, np)
			continue
		}
		if !isPrime(np) {
			t.Errorf("makePrime(%d) == %d is not prime", i, np)
			continue
		}
		if isPrime(i) && i != np {
			t.Errorf("%d is already prime, but got %d as next prime", i, np)
			continue
		}
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present 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

import (
	"context"
	"io"
	"os"
	"path/filepath"
	"time"

	"zettelstore.de/z/box/filebox"
	"zettelstore.de/z/box/notify"
	"zettelstore.de/z/input"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/zettel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

func fileService(i uint32, log *logger.Logger, dirPath string, cmds <-chan fileCmd) {
	// Something may panic. Ensure a running service.
	defer func() {
		if r := recover(); r != nil {
			kernel.Main.LogRecover("FileService", r)
			go fileService(i, log, dirPath, cmds)
		}
	}()

	log.Trace().Uint("i", uint64(i)).Str("dirpath", dirPath).Msg("File service started")
	for cmd := range cmds {
		cmd.run(log, dirPath)
	}
	log.Trace().Uint("i", uint64(i)).Str("dirpath", dirPath).Msg("File service stopped")
}

type fileCmd interface {
	run(*logger.Logger, string)
}

const serviceTimeout = 5 * time.Second // must be shorter than the web servers timeout values for reading+writing.

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

func (dp *dirBox) srvGetMeta(ctx context.Context, entry *notify.DirEntry, zid id.Zid) (*meta.Meta, error) {
	rc := make(chan resGetMeta, 1)
	dp.getFileChan(zid) <- &fileGetMeta{entry, rc}
	ctx, cancel := context.WithTimeout(ctx, serviceTimeout)
	defer cancel()
	select {
	case res := <-rc:
		return res.meta, res.err
	case <-ctx.Done():
		return nil, ctx.Err()
	}
}

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

func (cmd *fileGetMeta) run(log *logger.Logger, dirPath string) {
	var m *meta.Meta
	var err error

	entry := cmd.entry
	zid := entry.Zid
	if metaName := entry.MetaName; metaName == "" {
		contentName := entry.ContentName
		contentExt := entry.ContentExt
		if contentName == "" || contentExt == "" {
			log.Panic().Zid(zid).Msg("No meta, no content in getMeta")
		}
		if entry.HasMetaInContent() {
			m, _, err = parseMetaContentFile(zid, filepath.Join(dirPath, contentName))
		} else {
			m = filebox.CalcDefaultMeta(zid, contentExt)
		}
	} else {
		m, err = parseMetaFile(zid, filepath.Join(dirPath, metaName))
	}
	if err == nil {
		cmdCleanupMeta(m, entry)
	}
	cmd.rc <- resGetMeta{m, err}
}

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

func (dp *dirBox) srvGetMetaContent(ctx context.Context, entry *notify.DirEntry, zid id.Zid) (*meta.Meta, []byte, error) {
	rc := make(chan resGetMetaContent, 1)
	dp.getFileChan(zid) <- &fileGetMetaContent{entry, rc}
	ctx, cancel := context.WithTimeout(ctx, serviceTimeout)
	defer cancel()
	select {
	case res := <-rc:
		return res.meta, res.content, res.err
	case <-ctx.Done():
		return nil, nil, ctx.Err()
	}
}

type fileGetMetaContent struct {
	entry *notify.DirEntry
	rc    chan<- resGetMetaContent
}
type resGetMetaContent struct {
	meta    *meta.Meta
	content []byte
	err     error
}

func (cmd *fileGetMetaContent) run(log *logger.Logger, dirPath string) {
	var m *meta.Meta
	var content []byte
	var err error

	entry := cmd.entry
	zid := entry.Zid
	contentName := entry.ContentName
	contentExt := entry.ContentExt
	contentPath := filepath.Join(dirPath, contentName)
	if metaName := entry.MetaName; metaName == "" {
		if contentName == "" || contentExt == "" {
			log.Panic().Zid(zid).Msg("No meta, no content in getMetaContent")
		}
		if entry.HasMetaInContent() {
			m, content, err = parseMetaContentFile(zid, contentPath)
		} else {
			m = filebox.CalcDefaultMeta(zid, contentExt)
			content, err = os.ReadFile(contentPath)
		}
	} else {
		m, err = parseMetaFile(zid, filepath.Join(dirPath, metaName))
		if contentName != "" {
			var err1 error
			content, err1 = os.ReadFile(contentPath)
			if err == nil {
				err = err1
			}
		}
	}
	if err == nil {
		cmdCleanupMeta(m, entry)
	}
	cmd.rc <- resGetMetaContent{m, content, err}
}

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

func (dp *dirBox) srvSetZettel(ctx context.Context, entry *notify.DirEntry, zettel zettel.Zettel) error {
	rc := make(chan resSetZettel, 1)
	dp.getFileChan(zettel.Meta.Zid) <- &fileSetZettel{entry, zettel, rc}
	ctx, cancel := context.WithTimeout(ctx, serviceTimeout)
	defer cancel()
	select {
	case err := <-rc:
		return err
	case <-ctx.Done():
		return ctx.Err()
	}
}

type fileSetZettel struct {
	entry  *notify.DirEntry
	zettel zettel.Zettel
	rc     chan<- resSetZettel
}
type resSetZettel = error

func (cmd *fileSetZettel) run(log *logger.Logger, dirPath string) {
	entry := cmd.entry
	zid := entry.Zid
	contentName := entry.ContentName
	m := cmd.zettel.Meta
	content := cmd.zettel.Content.AsBytes()
	metaName := entry.MetaName
	if metaName == "" {
		if contentName == "" {
			log.Panic().Zid(zid).Msg("No meta, no content in setZettel")
		}
		contentPath := filepath.Join(dirPath, contentName)
		if entry.HasMetaInContent() {
			err := writeZettelFile(contentPath, m, content)
			cmd.rc <- err
			return
		}
		err := writeFileContent(contentPath, content)
		cmd.rc <- err
		return
	}

	err := writeMetaFile(filepath.Join(dirPath, metaName), m)
	if err == nil && contentName != "" {
		err = writeFileContent(filepath.Join(dirPath, contentName), content)
	}
	cmd.rc <- err
}

func writeMetaFile(metaPath string, m *meta.Meta) error {
	metaFile, err := openFileWrite(metaPath)
	if err != nil {
		return err
	}
	err = writeFileZid(metaFile, m.Zid)
	if err == nil {
		_, err = m.WriteComputed(metaFile)
	}
	if err1 := metaFile.Close(); err == nil {
		err = err1
	}
	return err
}

func writeZettelFile(contentPath string, m *meta.Meta, content []byte) error {
	zettelFile, err := openFileWrite(contentPath)
	if err != nil {
		return err
	}
	if err == nil {
		err = writeMetaHeader(zettelFile, m)
	}
	if err == nil {
		_, err = zettelFile.Write(content)
	}
	if err1 := zettelFile.Close(); err == nil {
		err = err1
	}
	return err
}

var (
	newline = []byte{'\n'}
	yamlSep = []byte{'-', '-', '-', '\n'}
)

func writeMetaHeader(w io.Writer, m *meta.Meta) (err error) {
	if m.YamlSep {
		_, err = w.Write(yamlSep)
		if err != nil {
			return err
		}
	}
	err = writeFileZid(w, m.Zid)
	if err != nil {
		return err
	}
	_, err = m.WriteComputed(w)
	if err != nil {
		return err
	}
	if m.YamlSep {
		_, err = w.Write(yamlSep)
	} else {
		_, err = w.Write(newline)
	}
	return err
}

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

func (dp *dirBox) srvDeleteZettel(ctx context.Context, entry *notify.DirEntry, zid id.Zid) error {
	rc := make(chan resDeleteZettel, 1)
	dp.getFileChan(zid) <- &fileDeleteZettel{entry, rc}
	ctx, cancel := context.WithTimeout(ctx, serviceTimeout)
	defer cancel()
	select {
	case err := <-rc:
		return err
	case <-ctx.Done():
		return ctx.Err()
	}
}

type fileDeleteZettel struct {
	entry *notify.DirEntry
	rc    chan<- resDeleteZettel
}
type resDeleteZettel = error

func (cmd *fileDeleteZettel) run(log *logger.Logger, dirPath string) {
	var err error

	entry := cmd.entry
	contentName := entry.ContentName
	contentPath := filepath.Join(dirPath, contentName)
	if metaName := entry.MetaName; metaName == "" {
		if contentName == "" {
			log.Panic().Zid(entry.Zid).Msg("No meta, no content in getMetaContent")
		}
		err = os.Remove(contentPath)
	} else {
		if contentName != "" {
			err = os.Remove(contentPath)
		}
		err1 := os.Remove(filepath.Join(dirPath, metaName))
		if err == nil {
			err = err1
		}
	}
	for _, dupName := range entry.UselessFiles {
		err1 := os.Remove(filepath.Join(dirPath, dupName))
		if err == nil {
			err = err1
		}
	}
	cmd.rc <- err
}

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

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

func cmdCleanupMeta(m *meta.Meta, entry *notify.DirEntry) {
	filebox.CleanupMeta(
		m,
		entry.Zid,
		entry.ContentExt,
		entry.MetaName != "",
		entry.UselessFiles,
	)
}

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

func writeFileZid(w io.Writer, zid id.Zid) error {
	_, err := io.WriteString(w, "id: ")
	if err == nil {
		_, err = w.Write(zid.Bytes())
		if err == nil {
			_, err = io.WriteString(w, "\n")
		}
	}
	return err
}

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

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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/client.fossil/api"
	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/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{
			log: kernel.Main.GetLogger(kernel.BoxService).Clone().
				Str("box", "zip").Int("boxnum", int64(cdata.Number)).Child(),
			number:   cdata.Number,
			name:     path,
			enricher: cdata.Enricher,
			notify:   cdata.Notify,
		}, 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(api.KeySyntax, calculateSyntax(ext))
	return m
}

// CleanupMeta enhances the given metadata.
func CleanupMeta(m *meta.Meta, zid id.Zid, ext string, inMeta bool, uselessFiles []string) {
	if inMeta {
		if syntax, ok := m.Get(api.KeySyntax); !ok || syntax == "" {
			dm := CalcDefaultMeta(zid, ext)
			syntax, ok = dm.Get(api.KeySyntax)
			if !ok {
				panic("Default meta must contain syntax")
			}
			m.Set(api.KeySyntax, syntax)
		}
	}

	if len(uselessFiles) > 0 {
		m.Set(api.KeyUselessFiles, strings.Join(uselessFiles, " "))
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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

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

	"zettelstore.de/z/box"
	"zettelstore.de/z/box/notify"
	"zettelstore.de/z/input"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/query"
	"zettelstore.de/z/zettel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

type zipBox struct {
	log      *logger.Logger
	number   int
	name     string
	enricher box.Enricher
	notify   chan<- box.UpdateInfo
	dirSrv   *notify.DirService
}

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

func (zb *zipBox) State() box.StartState {
	if ds := zb.dirSrv; ds != nil {
		switch ds.State() {
		case notify.DsCreated:
			return box.StartStateStopped
		case notify.DsStarting:
			return box.StartStateStarting
		case notify.DsWorking:
			return box.StartStateStarted
		case notify.DsMissing:
			return box.StartStateStarted
		case notify.DsStopping:
			return box.StartStateStopping
		}
	}
	return box.StartStateStopped
}

func (zb *zipBox) Start(context.Context) error {
	reader, err := zip.OpenReader(zb.name)
	if err != nil {
		return err
	}
	reader.Close()
	zipNotifier := notify.NewSimpleZipNotifier(zb.log, zb.name)
	zb.dirSrv = notify.NewDirService(zb, zb.log, zipNotifier, zb.notify)
	zb.dirSrv.Start()
	return nil
}

func (zb *zipBox) Refresh(_ context.Context) {
	zb.dirSrv.Refresh()
	zb.log.Trace().Msg("Refresh")
}

func (zb *zipBox) Stop(context.Context) {
	zb.dirSrv.Stop()
	zb.dirSrv = nil
}

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

func (zb *zipBox) CreateZettel(context.Context, zettel.Zettel) (id.Zid, error) {
	err := box.ErrReadOnly
	zb.log.Trace().Err(err).Msg("CreateZettel")
	return id.Invalid, err
}

func (zb *zipBox) GetZettel(_ context.Context, zid id.Zid) (zettel.Zettel, error) {
	entry := zb.dirSrv.GetDirEntry(zid)
	if !entry.IsValid() {
		return zettel.Zettel{}, box.ErrNotFound
	}
	reader, err := zip.OpenReader(zb.name)
	if err != nil {
		return zettel.Zettel{}, err
	}
	defer reader.Close()

	var m *meta.Meta
	var src []byte
	var inMeta bool

	contentName := entry.ContentName
	if metaName := entry.MetaName; metaName == "" {
		if contentName == "" {
			zb.log.Panic().Zid(zid).Msg("No meta, no content in zipBox.GetZettel")
		}
		src, err = readZipFileContent(reader, entry.ContentName)
		if err != nil {
			return zettel.Zettel{}, err
		}
		if entry.HasMetaInContent() {
			inp := input.NewInput(src)
			m = meta.NewFromInput(zid, inp)
			src = src[inp.Pos:]
		} else {
			m = CalcDefaultMeta(zid, entry.ContentExt)
		}
	} else {
		m, err = readZipMetaFile(reader, zid, metaName)
		if err != nil {
			return zettel.Zettel{}, err
		}
		inMeta = true
		if contentName != "" {
			src, err = readZipFileContent(reader, entry.ContentName)
			if err != nil {
				return zettel.Zettel{}, err
			}
		}
	}

	CleanupMeta(m, zid, entry.ContentExt, inMeta, entry.UselessFiles)
	zb.log.Trace().Zid(zid).Msg("GetZettel")
	return zettel.Zettel{Meta: m, Content: zettel.NewContent(src)}, nil
}

func (zb *zipBox) HasZettel(_ context.Context, zid id.Zid) bool {
	return zb.dirSrv.GetDirEntry(zid).IsValid()
}

func (zb *zipBox) ApplyZid(_ context.Context, handle box.ZidFunc, constraint query.RetrievePredicate) error {
	entries := zb.dirSrv.GetDirEntries(constraint)
	zb.log.Trace().Int("entries", int64(len(entries))).Msg("ApplyZid")
	for _, entry := range entries {
		handle(entry.Zid)
	}
	return nil
}

func (zb *zipBox) ApplyMeta(ctx context.Context, handle box.MetaFunc, constraint query.RetrievePredicate) error {
	reader, err := zip.OpenReader(zb.name)
	if err != nil {
		return err
	}
	defer reader.Close()
	entries := zb.dirSrv.GetDirEntries(constraint)
	zb.log.Trace().Int("entries", int64(len(entries))).Msg("ApplyMeta")
	for _, entry := range entries {
		if !constraint(entry.Zid) {
			continue
		}
		m, err2 := zb.readZipMeta(reader, entry.Zid, entry)
		if err2 != nil {
			continue
		}
		zb.enricher.Enrich(ctx, m, zb.number)
		handle(m)
	}
	return nil
}

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

func (zb *zipBox) UpdateZettel(context.Context, zettel.Zettel) error {
	err := box.ErrReadOnly
	zb.log.Trace().Err(err).Msg("UpdateZettel")
	return err
}

func (zb *zipBox) AllowRenameZettel(_ context.Context, zid id.Zid) bool {
	entry := zb.dirSrv.GetDirEntry(zid)
	return !entry.IsValid()
}

func (zb *zipBox) RenameZettel(_ context.Context, curZid, newZid id.Zid) error {
	err := box.ErrReadOnly
	if curZid == newZid {
		err = nil
	}
	curEntry := zb.dirSrv.GetDirEntry(curZid)
	if !curEntry.IsValid() {
		err = box.ErrNotFound
	}
	zb.log.Trace().Err(err).Msg("RenameZettel")
	return err
}

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

func (zb *zipBox) DeleteZettel(_ context.Context, zid id.Zid) error {
	err := box.ErrReadOnly
	entry := zb.dirSrv.GetDirEntry(zid)
	if !entry.IsValid() {
		err = box.ErrNotFound
	}
	zb.log.Trace().Err(err).Msg("DeleteZettel")
	return err
}

func (zb *zipBox) ReadStats(st *box.ManagedBoxStats) {
	st.ReadOnly = true
	st.Zettel = zb.dirSrv.NumDirEntries()
	zb.log.Trace().Int("zettel", int64(st.Zettel)).Msg("ReadStats")
}

func (zb *zipBox) readZipMeta(reader *zip.ReadCloser, zid id.Zid, entry *notify.DirEntry) (m *meta.Meta, err error) {
	var inMeta bool
	if metaName := entry.MetaName; metaName == "" {
		contentName := entry.ContentName
		contentExt := entry.ContentExt
		if contentName == "" || contentExt == "" {
			zb.log.Panic().Zid(zid).Msg("No meta, no content in getMeta")
		}
		if entry.HasMetaInContent() {
			m, err = readZipMetaFile(reader, zid, contentName)
		} else {
			m = CalcDefaultMeta(zid, contentExt)
		}
	} else {
		m, err = readZipMetaFile(reader, zid, metaName)
	}
	if err == nil {
		CleanupMeta(m, zid, entry.ContentExt, inMeta, entry.UselessFiles)
	}
	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) ([]byte, error) {
	f, err := reader.Open(name)
	if err != nil {
		return nil, err
	}
	defer f.Close()
	return io.ReadAll(f)
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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

import (
	"net/url"
	"strconv"
	"time"

	"zettelstore.de/z/zettel/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
}

// GetQueryBool is a helper function to extract bool values from a box URI.
func GetQueryBool(u *url.URL, key string) bool {
	_, ok := u.Query()[key]
	return ok
}

// GetQueryInt is a helper function to extract int values of a specified range from a box URI.
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
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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

import (
	"sync"

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

type arAction int

const (
	arNothing arAction = iota
	arReload
	arZettel
)

type anteroom struct {
	num     uint64
	next    *anteroom
	waiting id.Set
	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) EnqueueZettel(zid id.Zid) {
	if !zid.IsValid() {
		return
	}
	ar.mx.Lock()
	defer ar.mx.Unlock()
	if ar.first == nil {
		ar.first = ar.makeAnteroom(zid)
		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
		}
		if _, ok := room.waiting[zid]; ok {
			// Zettel is already waiting. Nothing to do.
			return
		}
	}
	if room := ar.last; !room.reload && (ar.maxLoad == 0 || room.curLoad < ar.maxLoad) {
		room.waiting.Zid(zid)
		room.curLoad++
		return
	}
	room := ar.makeAnteroom(zid)
	ar.last.next = room
	ar.last = room
}

func (ar *anterooms) makeAnteroom(zid id.Zid) *anteroom {
	ar.nextNum++
	if zid == id.Invalid {
		return &anteroom{num: ar.nextNum, next: nil, waiting: nil, curLoad: 0, reload: true}
	}
	c := ar.maxLoad
	if c == 0 {
		c = 100
	}
	waiting := id.NewSetCap(ar.maxLoad, zid)
	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)
	ar.last = ar.first
}

func (ar *anterooms) Reload(newZids id.Set) uint64 {
	ar.mx.Lock()
	defer ar.mx.Unlock()
	ar.deleteReloadedRooms()

	if ns := len(newZids); ns > 0 {
		ar.nextNum++
		ar.first = &anteroom{num: ar.nextNum, next: ar.first, waiting: newZids, curLoad: ns, reload: true}
		if ar.first.next == nil {
			ar.last = ar.first
		}
		return ar.nextNum
	}

	ar.first = nil
	ar.last = nil
	return 0
}

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
	}
	roomNo := ar.first.num
	if ar.first.waiting == nil {
		ar.removeFirst()
		return arReload, id.Invalid, roomNo
	}
	for zid := range ar.first.waiting {
		delete(ar.first.waiting, zid)
		if len(ar.first.waiting) == 0 {
			ar.removeFirst()
		}
		return arZettel, zid, roomNo
	}
	ar.removeFirst()
	return arNothing, id.Invalid, 0
}

func (ar *anterooms) removeFirst() {
	ar.first = ar.first.next
	if ar.first == nil {
		ar.last = nil
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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

import (
	"testing"

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

func TestSimple(t *testing.T) {
	t.Parallel()
	ar := newAnterooms(2)
	ar.EnqueueZettel(id.Zid(1))
	action, zid, rno := ar.Dequeue()
	if zid != id.Zid(1) || action != arZettel || rno != 1 {
		t.Errorf("Expected arZettel/1/1, but got %v/%v/%v", action, zid, rno)
	}
	_, zid, _ = ar.Dequeue()
	if zid != id.Invalid {
		t.Errorf("Expected invalid Zid, but got %v", zid)
	}
	ar.EnqueueZettel(id.Zid(1))
	ar.EnqueueZettel(id.Zid(2))
	if ar.first != ar.last {
		t.Errorf("Expected one room, but got more")
	}
	ar.EnqueueZettel(id.Zid(3))
	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.EnqueueZettel(id.Zid(1))
	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.EnqueueZettel(id.Zid(5))
	ar.EnqueueZettel(id.Zid(5))
	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 != arZettel {
		t.Errorf("Expected arZettel, but got %v", action)
	}
	action, zid2, _ := ar.Dequeue()
	if action != arZettel {
		t.Errorf("Expected arZettel, 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 != arZettel {
		t.Errorf("Expected 5/arZettel, 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 != arZettel {
		t.Errorf("Expected 6/arZettel, 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.EnqueueZettel(id.Zid(8))
	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-present 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

import (
	"context"
	"errors"
	"strings"

	"zettelstore.de/z/box"
	"zettelstore.de/z/query"
	"zettelstore.de/z/zettel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

// 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.State() == box.StartStateStarted && mgr.boxes[0].CanCreateZettel(ctx)
}

// CreateZettel creates a new zettel.
func (mgr *Manager) CreateZettel(ctx context.Context, zettel zettel.Zettel) (id.Zid, error) {
	mgr.mgrLog.Debug().Msg("CreateZettel")
	if mgr.State() != box.StartStateStarted {
		return id.Invalid, box.ErrStopped
	}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	return mgr.boxes[0].CreateZettel(ctx, zettel)
}

// GetZettel retrieves a specific zettel.
func (mgr *Manager) GetZettel(ctx context.Context, zid id.Zid) (zettel.Zettel, error) {
	mgr.mgrLog.Debug().Zid(zid).Msg("GetZettel")
	if mgr.State() != box.StartStateStarted {
		return zettel.Zettel{}, box.ErrStopped
	}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	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 zettel.Zettel{}, box.ErrNotFound
}

// GetAllZettel retrieves a specific zettel from all managed boxes.
func (mgr *Manager) GetAllZettel(ctx context.Context, zid id.Zid) ([]zettel.Zettel, error) {
	mgr.mgrLog.Debug().Zid(zid).Msg("GetAllZettel")
	if mgr.State() != box.StartStateStarted {
		return nil, box.ErrStopped
	}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	var result []zettel.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
}

// FetchZids returns the set of all zettel identifer managed by the box.
func (mgr *Manager) FetchZids(ctx context.Context) (id.Set, error) {
	mgr.mgrLog.Debug().Msg("FetchZids")
	if mgr.State() != box.StartStateStarted {
		return nil, box.ErrStopped
	}
	result := id.Set{}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	for _, p := range mgr.boxes {
		err := p.ApplyZid(ctx, func(zid id.Zid) { result.Zid(zid) }, func(id.Zid) bool { return true })
		if err != nil {
			return nil, err
		}
	}
	return result, nil
}

func (mgr *Manager) HasZettel(ctx context.Context, zid id.Zid) bool {
	mgr.mgrLog.Debug().Zid(zid).Msg("HasZettel")
	if mgr.State() != box.StartStateStarted {
		return false
	}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	for _, bx := range mgr.boxes {
		if bx.HasZettel(ctx, zid) {
			return true
		}
	}
	return false
}

func (mgr *Manager) GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
	mgr.mgrLog.Debug().Zid(zid).Msg("GetMeta")
	if mgr.State() != box.StartStateStarted {
		return nil, box.ErrStopped
	}

	m, err := mgr.idxStore.GetMeta(ctx, zid)
	if err != nil {
		return nil, err
	}
	mgr.Enrich(ctx, m, 0)
	return m, 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, metaSeq []*meta.Meta, q *query.Query) ([]*meta.Meta, error) {
	if msg := mgr.mgrLog.Debug(); msg.Enabled() {
		msg.Str("query", q.String()).Msg("SelectMeta")
	}
	if mgr.State() != box.StartStateStarted {
		return nil, box.ErrStopped
	}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()

	compSearch := q.RetrieveAndCompile(ctx, mgr, metaSeq)
	if result := compSearch.Result(); result != nil {
		mgr.mgrLog.Trace().Int("count", int64(len(result))).Msg("found without ApplyMeta")
		return result, nil
	}
	selected := map[id.Zid]*meta.Meta{}
	for _, term := range compSearch.Terms {
		rejected := id.Set{}
		handleMeta := func(m *meta.Meta) {
			zid := m.Zid
			if rejected.Contains(zid) {
				mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/alreadyRejected")
				return
			}
			if _, ok := selected[zid]; ok {
				mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/alreadySelected")
				return
			}
			if compSearch.PreMatch(m) && term.Match(m) {
				selected[zid] = m
				mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/match")
			} else {
				rejected.Zid(zid)
				mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/reject")
			}
		}
		for _, p := range mgr.boxes {
			if err2 := p.ApplyMeta(ctx, handleMeta, term.Retrieve); err2 != nil {
				return nil, err2
			}
		}
	}
	result := make([]*meta.Meta, 0, len(selected))
	for _, m := range selected {
		result = append(result, m)
	}
	result = compSearch.AfterSearch(result)
	mgr.mgrLog.Trace().Int("count", int64(len(result))).Msg("found with ApplyMeta")
	return result, nil
}

// CanUpdateZettel returns true, if box could possibly update the given zettel.
func (mgr *Manager) CanUpdateZettel(ctx context.Context, zettel zettel.Zettel) bool {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	return mgr.State() == box.StartStateStarted && mgr.boxes[0].CanUpdateZettel(ctx, zettel)
}

// UpdateZettel updates an existing zettel.
func (mgr *Manager) UpdateZettel(ctx context.Context, zettel zettel.Zettel) error {
	mgr.mgrLog.Debug().Zid(zettel.Meta.Zid).Msg("UpdateZettel")
	if mgr.State() != box.StartStateStarted {
		return box.ErrStopped
	}
	// Remove all (computed) properties from metadata before storing the zettel.
	zettel.Meta = zettel.Meta.Clone()
	for _, p := range zettel.Meta.ComputedPairsRest() {
		if mgr.propertyKeys.Has(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 {
	if mgr.State() != box.StartStateStarted {
		return false
	}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	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.mgrLog.Debug().Zid(curZid).Zid(newZid).Msg("RenameZettel")
	if mgr.State() != box.StartStateStarted {
		return box.ErrStopped
	}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	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 {
	if mgr.State() != box.StartStateStarted {
		return false
	}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	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.mgrLog.Debug().Zid(zid).Msg("DeleteZettel")
	if mgr.State() != box.StartStateStarted {
		return box.ErrStopped
	}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	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-present 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

import (
	"strings"

	"zettelstore.de/z/ast"
	"zettelstore.de/z/box/manager/store"
	"zettelstore.de/z/strfun"
	"zettelstore.de/z/zettel/id"
)

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.Walk(data, &zn.Ast)
}

func collectInlineIndexData(is *ast.InlineSlice, data *collectData) {
	ast.Walk(data, is)
}

func (data *collectData) Visit(node ast.Node) ast.Visitor {
	switch n := node.(type) {
	case *ast.VerbatimNode:
		data.addText(string(n.Content))
	case *ast.TranscludeNode:
		data.addRef(n.Ref)
	case *ast.TextNode:
		data.addText(n.Text)
	case *ast.LinkNode:
		data.addRef(n.Ref)
	case *ast.EmbedRefNode:
		data.addRef(n.Ref)
	case *ast.CiteNode:
		data.addText(n.Key)
	case *ast.LiteralNode:
		data.addText(string(n.Content))
	}
	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(zid)
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present 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

import (
	"context"
	"strconv"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/box"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

// Enrich computes additional properties and updates the given metadata.
func (mgr *Manager) Enrich(ctx context.Context, m *meta.Meta, boxNumber int) {

	// Calculate computed, but stored values.
	if _, ok := m.Get(api.KeyCreated); !ok {
		m.Set(api.KeyCreated, computeCreated(m.Zid))
	}

	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 metadata
		return
	}
	computePublished(m)
	if boxNumber > 0 {
		m.Set(api.KeyBoxNumber, strconv.Itoa(boxNumber))
	}
	mgr.idxStore.Enrich(ctx, m)
}

func computeCreated(zid id.Zid) string {
	if zid <= 10101000000 {
		// A year 0000 is not allowed and therefore an artificaial Zid.
		// In the year 0001, the month must be > 0.
		// In the month 000101, the day must be > 0.
		return "00010101000000"
	}
	seconds := zid % 100
	if seconds > 59 {
		seconds = 59
	}
	zid /= 100
	minutes := zid % 100
	if minutes > 59 {
		minutes = 59
	}
	zid /= 100
	hours := zid % 100
	if hours > 23 {
		hours = 23
	}
	zid /= 100
	day := zid % 100
	zid /= 100
	month := zid % 100
	year := zid / 100
	month, day = sanitizeMonthDay(year, month, day)
	created := ((((year*100+month)*100+day)*100+hours)*100+minutes)*100 + seconds
	return created.String()
}

func sanitizeMonthDay(year, month, day id.Zid) (id.Zid, id.Zid) {
	if day < 1 {
		day = 1
	}
	if month < 1 {
		month = 1
	}
	if month > 12 {
		month = 12
	}

	switch month {
	case 1, 3, 5, 7, 8, 10, 12:
		if day > 31 {
			day = 31
		}
	case 4, 6, 9, 11:
		if day > 30 {
			day = 30
		}
	case 2:
		if year%4 != 0 || (year%100 == 0 && year%400 != 0) {
			if day > 28 {
				day = 28
			}
		} else {
			if day > 29 {
				day = 29
			}
		}
	}
	return month, day
}

func computePublished(m *meta.Meta) {
	if _, ok := m.Get(api.KeyPublished); ok {
		return
	}
	if modified, ok := m.Get(api.KeyModified); ok {
		if _, ok = meta.TimeValue(modified); ok {
			m.Set(api.KeyPublished, modified)
			return
		}
	}
	if created, ok := m.Get(api.KeyCreated); ok {
		if _, ok = meta.TimeValue(created); ok {
			m.Set(api.KeyPublished, created)
			return
		}
	}
	zid := m.Zid.String()
	if _, ok := meta.TimeValue(zid); ok {
		m.Set(api.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.
}