0.20.0
0.21.0-dev

//-----------------------------------------------------------------------------
// 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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

// Package ast provides the abstract syntax tree for parsed zettel content.
package ast

import (
	"net/url"

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/zettel"
)

// 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.
	BlocksAST 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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package ast

import "t73f.de/r/zsc/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
	VerbatimCode                 // 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]) // 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
			}
		}
	}
}

// WalkChildren walks the list of inline elements.
func (cell *TableCell) WalkChildren(v Visitor) {
	Walk(v, &cell.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
	Inlines InlineSlice // Optional text.
}

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

// WalkChildren walks the associated text.
func (tn *TranscludeNode) WalkChildren(v Visitor) { Walk(v, &tn.Inlines) }

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

// 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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package ast

import (
	"t73f.de/r/zsc/attrs"
)

// Definitions of inline nodes.

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

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

// WalkChildren walks down to the list.
func (is *InlineSlice) WalkChildren(v Visitor) {
	if is != nil {
		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*/ }

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

// 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
	FormatMark              // Marked 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
	LiteralCode                // Inline program code
	LiteralInput               // Computer input, e.g. Keyboard strokes
	LiteralOutput              // Computer output
	LiteralComment             // Inline comment
	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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package ast

import (
	"net/url"
	"strings"

	"t73f.de/r/zsc/api"
	"t73f.de/r/zsc/domain/id"
)

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

// 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.State == RefStateQuery {
		return QueryPrefix + r.Value
	}
	if r.URL != nil {
		return r.URL.String()
	}
	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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

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) 2025-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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2025-present Detlef Stern
//-----------------------------------------------------------------------------

// Package sztrans allows to transform a sz representation of text into an
// abstract syntax tree.
package sztrans

import (
	"fmt"
	"log"

	"t73f.de/r/sx"
	"t73f.de/r/zsc/sz"
	"zettelstore.de/z/ast"
)

type transformer struct{}

// GetBlockSlice returns the sz representations as a AST BlockSlice
func GetBlockSlice(pair *sx.Pair) (ast.BlockSlice, error) {
	if pair == nil {
		return nil, nil
	}
	var t transformer
	if obj := sz.Walk(&t, pair, nil); !obj.IsNil() {
		if sxn, isNode := obj.(sxNode); isNode {
			if bs, ok := sxn.node.(*ast.BlockSlice); ok {
				return *bs, nil
			}
			return nil, fmt.Errorf("no BlockSlice AST: %T/%v for %v", sxn.node, sxn.node, pair)
		}
		return nil, fmt.Errorf("no AST for %v: %v", pair, obj)
	}
	return nil, fmt.Errorf("error walking %v", pair)
}

func (t *transformer) VisitBefore(pair *sx.Pair, _ *sx.Pair) (sx.Object, bool) {
	if sym, isSymbol := sx.GetSymbol(pair.Car()); isSymbol {
		switch sym {
		case sz.SymText:
			if p := pair.Tail(); p != nil {
				if s, isString := sx.GetString(p.Car()); isString {
					return sxNode{&ast.TextNode{Text: s.GetValue()}}, true
				}
			}
		case sz.SymSoft:
			return sxNode{&ast.BreakNode{Hard: false}}, true
		case sz.SymHard:
			return sxNode{&ast.BreakNode{Hard: true}}, true
		case sz.SymLiteralCode:
			return handleLiteral(ast.LiteralCode, pair.Tail())
		case sz.SymLiteralComment:
			return handleLiteral(ast.LiteralComment, pair.Tail())
		case sz.SymLiteralInput:
			return handleLiteral(ast.LiteralInput, pair.Tail())
		case sz.SymLiteralMath:
			return handleLiteral(ast.LiteralMath, pair.Tail())
		case sz.SymLiteralOutput:
			return handleLiteral(ast.LiteralOutput, pair.Tail())
		case sz.SymThematic:
			return sxNode{&ast.HRuleNode{Attrs: sz.GetAttributes(pair.Tail().Head())}}, true
		case sz.SymVerbatimComment:
			return handleVerbatim(ast.VerbatimComment, pair.Tail())
		case sz.SymVerbatimEval:
			return handleVerbatim(ast.VerbatimEval, pair.Tail())
		case sz.SymVerbatimHTML:
			return handleVerbatim(ast.VerbatimHTML, pair.Tail())
		case sz.SymVerbatimMath:
			return handleVerbatim(ast.VerbatimMath, pair.Tail())
		case sz.SymVerbatimCode:
			return handleVerbatim(ast.VerbatimCode, pair.Tail())
		case sz.SymVerbatimZettel:
			return handleVerbatim(ast.VerbatimZettel, pair.Tail())
		}
	}
	return sx.Nil(), false
}

func handleLiteral(kind ast.LiteralKind, rest *sx.Pair) (sx.Object, bool) {
	if rest != nil {
		attrs := sz.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			if s, isString := sx.GetString(curr.Car()); isString {
				return sxNode{&ast.LiteralNode{
					Kind:    kind,
					Attrs:   attrs,
					Content: []byte(s.GetValue())}}, true
			}
		}
	}
	return nil, false
}

func handleVerbatim(kind ast.VerbatimKind, rest *sx.Pair) (sx.Object, bool) {
	if rest != nil {
		attrs := sz.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			if s, isString := sx.GetString(curr.Car()); isString {
				return sxNode{&ast.VerbatimNode{
					Kind:    kind,
					Attrs:   attrs,
					Content: []byte(s.GetValue()),
				}}, true
			}
		}
	}
	return nil, false
}

func (t *transformer) VisitAfter(pair *sx.Pair, _ *sx.Pair) sx.Object {
	if sym, isSymbol := sx.GetSymbol(pair.Car()); isSymbol {
		switch sym {
		case sz.SymBlock:
			bns := collectBlocks(pair.Tail())
			return sxNode{&bns}
		case sz.SymPara:
			return sxNode{&ast.ParaNode{Inlines: collectInlines(pair.Tail())}}
		case sz.SymHeading:
			return handleHeading(pair.Tail())
		case sz.SymListOrdered:
			return sxNode{&ast.NestedListNode{
				Kind:  ast.NestedListOrdered,
				Items: collectItemSlices(pair.Tail()),
				Attrs: nil}}
		case sz.SymListUnordered:
			return sxNode{&ast.NestedListNode{
				Kind:  ast.NestedListUnordered,
				Items: collectItemSlices(pair.Tail()),
				Attrs: nil}}
		case sz.SymListQuote:
			return sxNode{&ast.NestedListNode{
				Kind:  ast.NestedListQuote,
				Items: collectItemSlices(pair.Tail()),
				Attrs: nil}}
		case sz.SymDescription:
			return handleDescription(pair.Tail())
		case sz.SymTable:
			return handleTable(pair.Tail())
		case sz.SymCell:
			return handleCell(ast.AlignDefault, pair.Tail())
		case sz.SymCellCenter:
			return handleCell(ast.AlignCenter, pair.Tail())
		case sz.SymCellLeft:
			return handleCell(ast.AlignLeft, pair.Tail())
		case sz.SymCellRight:
			return handleCell(ast.AlignRight, pair.Tail())
		case sz.SymRegionBlock:
			return handleRegion(ast.RegionSpan, pair.Tail())
		case sz.SymRegionQuote:
			return handleRegion(ast.RegionQuote, pair.Tail())
		case sz.SymRegionVerse:
			return handleRegion(ast.RegionVerse, pair.Tail())
		case sz.SymTransclude:
			return handleTransclude(pair.Tail())

		case sz.SymLinkHosted:
			return handleLink(ast.RefStateHosted, pair.Tail())
		case sz.SymLinkInvalid:
			return handleLink(ast.RefStateInvalid, pair.Tail())
		case sz.SymLinkZettel:
			return handleLink(ast.RefStateZettel, pair.Tail())
		case sz.SymLinkSelf:
			return handleLink(ast.RefStateSelf, pair.Tail())
		case sz.SymLinkFound:
			return handleLink(ast.RefStateFound, pair.Tail())
		case sz.SymLinkBroken:
			return handleLink(ast.RefStateBroken, pair.Tail())
		case sz.SymLinkHosted:
			return handleLink(ast.RefStateHosted, pair.Tail())
		case sz.SymLinkBased:
			return handleLink(ast.RefStateBased, pair.Tail())
		case sz.SymLinkQuery:
			return handleLink(ast.RefStateQuery, pair.Tail())
		case sz.SymLinkExternal:
			return handleLink(ast.RefStateExternal, pair.Tail())
		case sz.SymEmbed:
			return handleEmbed(pair.Tail())
		case sz.SymCite:
			return handleCite(pair.Tail())
		case sz.SymMark:
			return handleMark(pair.Tail())
		case sz.SymEndnote:
			return handleEndnote(pair.Tail())
		case sz.SymFormatDelete:
			return handleFormat(ast.FormatDelete, pair.Tail())
		case sz.SymFormatEmph:
			return handleFormat(ast.FormatEmph, pair.Tail())
		case sz.SymFormatInsert:
			return handleFormat(ast.FormatInsert, pair.Tail())
		case sz.SymFormatMark:
			return handleFormat(ast.FormatMark, pair.Tail())
		case sz.SymFormatQuote:
			return handleFormat(ast.FormatQuote, pair.Tail())
		case sz.SymFormatSpan:
			return handleFormat(ast.FormatSpan, pair.Tail())
		case sz.SymFormatSub:
			return handleFormat(ast.FormatSub, pair.Tail())
		case sz.SymFormatSuper:
			return handleFormat(ast.FormatSuper, pair.Tail())
		case sz.SymFormatStrong:
			return handleFormat(ast.FormatStrong, pair.Tail())
		}
		log.Println("MISS", pair)
	}
	return pair
}

func collectBlocks(lst *sx.Pair) (result ast.BlockSlice) {
	for val := range lst.Values() {
		if sxn, isNode := val.(sxNode); isNode {
			if bn, isInline := sxn.node.(ast.BlockNode); isInline {
				result = append(result, bn)
			}
		}
	}
	return result
}

func collectInlines(lst *sx.Pair) (result ast.InlineSlice) {
	for val := range lst.Values() {
		if sxn, isNode := val.(sxNode); isNode {
			if in, isInline := sxn.node.(ast.InlineNode); isInline {
				result = append(result, in)
			}
		}
	}
	return result
}

func handleHeading(rest *sx.Pair) sx.Object {
	if rest != nil {
		if num, isNumber := rest.Car().(sx.Int64); isNumber && num > 0 && num < 6 {
			if curr := rest.Tail(); curr != nil {
				attrs := sz.GetAttributes(curr.Head())
				if curr = curr.Tail(); curr != nil {
					if sSlug, isSlug := sx.GetString(curr.Car()); isSlug {
						if curr = curr.Tail(); curr != nil {
							if sUniq, isUniq := sx.GetString(curr.Car()); isUniq {
								return sxNode{&ast.HeadingNode{
									Level:    int(num),
									Attrs:    attrs,
									Slug:     sSlug.GetValue(),
									Fragment: sUniq.GetValue(),
									Inlines:  collectInlines(curr.Tail()),
								}}
							}
						}
					}
				}
			}
		}
	}
	log.Println("HEAD", rest)
	return rest
}

func collectItemSlices(lst *sx.Pair) (result []ast.ItemSlice) {
	for val := range lst.Values() {
		if sxn, isNode := val.(sxNode); isNode {
			if bns, isBlockSlice := sxn.node.(*ast.BlockSlice); isBlockSlice {
				items := make(ast.ItemSlice, len(*bns))
				for i, bn := range *bns {
					if it, ok := bn.(ast.ItemNode); ok {
						items[i] = it
					}
				}
				result = append(result, items)
			}
			if ins, isInline := sxn.node.(*ast.InlineSlice); isInline {
				items := make(ast.ItemSlice, len(*ins))
				for i, bn := range *ins {
					if it, ok := bn.(ast.ItemNode); ok {
						items[i] = it
					}
				}
				result = append(result, items)
			}
		}
	}
	return result
}

func handleDescription(rest *sx.Pair) sx.Object {
	var descs []ast.Description
	for curr := rest; curr != nil; {
		term := collectInlines(curr.Head())
		curr = curr.Tail()
		if curr == nil {
			descr := ast.Description{Term: term, Descriptions: nil}
			descs = append(descs, descr)
			break
		}

		car := curr.Car()
		if sx.IsNil(car) {
			descs = append(descs, ast.Description{Term: term, Descriptions: nil})
			curr = curr.Tail()
			continue
		}

		sxn, isNode := car.(sxNode)
		if !isNode {
			descs = nil
			break
		}
		blocks, isBlocks := sxn.node.(*ast.BlockSlice)
		if !isBlocks {
			descs = nil
			break
		}

		descSlice := make([]ast.DescriptionSlice, 0, len(*blocks))
		for _, bn := range *blocks {
			bns, isBns := bn.(*ast.BlockSlice)
			if !isBns {
				continue
			}
			ds := make(ast.DescriptionSlice, 0, len(*bns))
			for _, b := range *bns {
				if defNode, isDef := b.(ast.DescriptionNode); isDef {
					ds = append(ds, defNode)
				}
			}
			descSlice = append(descSlice, ds)
		}

		descr := ast.Description{Term: term, Descriptions: descSlice}
		descs = append(descs, descr)

		curr = curr.Tail()
	}
	if len(descs) > 0 {
		return sxNode{&ast.DescriptionListNode{Descriptions: descs}}
	}
	log.Println("DESC", rest)
	return rest
}

func handleTable(rest *sx.Pair) sx.Object {
	if rest != nil {
		header := collectRow(rest.Head())
		cols := len(header)

		var rows []ast.TableRow
		for curr := range rest.Tail().Pairs() {
			row := collectRow(curr.Head())
			rows = append(rows, row)
			cols = max(cols, len(row))
		}
		align := make([]ast.Alignment, cols)
		for i := range cols {
			align[i] = ast.AlignDefault
		}

		return sxNode{&ast.TableNode{
			Header: header,
			Align:  align,
			Rows:   rows,
		}}
	}
	log.Println("TABL", rest)
	return rest
}

func collectRow(lst *sx.Pair) (row ast.TableRow) {
	for curr := range lst.Values() {
		if sxn, isNode := curr.(sxNode); isNode {
			if cell, isCell := sxn.node.(*ast.TableCell); isCell {
				row = append(row, cell)
			}
		}
	}
	return row
}

func handleCell(align ast.Alignment, rest *sx.Pair) sx.Object {
	return sxNode{&ast.TableCell{
		Align:   align,
		Inlines: collectInlines(rest),
	}}
}

func handleRegion(kind ast.RegionKind, rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := sz.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			if blockList := curr.Head(); blockList != nil {
				return sxNode{&ast.RegionNode{
					Kind:    kind,
					Attrs:   attrs,
					Blocks:  collectBlocks(blockList),
					Inlines: collectInlines(curr.Tail()),
				}}
			}
		}
	}
	log.Println("REGI", rest)
	return rest
}

func handleTransclude(rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := sz.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			ref := collectReference(curr.Head())
			return sxNode{&ast.TranscludeNode{
				Attrs:   attrs,
				Ref:     ref,
				Inlines: collectInlines(curr.Tail()),
			}}
		}
	}
	log.Println("TRAN", rest)
	return rest
}

func handleLink(state ast.RefState, rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := sz.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			if sref, isString := sx.GetString(curr.Car()); isString {
				ref := ast.ParseReference(sref.GetValue())
				ref.State = state
				ins := collectInlines(curr.Tail())
				return sxNode{&ast.LinkNode{
					Attrs:   attrs,
					Ref:     ref,
					Inlines: ins,
				}}
			}
		}
	}
	log.Println("LINK", state, rest)
	return rest
}

func handleEmbed(rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := sz.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			if ref := collectReference(curr.Head()); ref != nil {
				if curr = curr.Tail(); curr != nil {
					if syntax, isString := sx.GetString(curr.Car()); isString {
						return sxNode{&ast.EmbedRefNode{
							Attrs:   attrs,
							Ref:     ref,
							Syntax:  syntax.GetValue(),
							Inlines: collectInlines(curr.Tail()),
						}}
					}
				}
			}
		}
	}
	log.Println("EMBE", rest)
	return rest
}

func collectReference(pair *sx.Pair) *ast.Reference {
	if pair != nil {
		if sym, isSymbol := sx.GetSymbol(pair.Car()); isSymbol {
			if next := pair.Tail(); next != nil {
				if sRef, isString := sx.GetString(next.Car()); isString {
					ref := ast.ParseReference(sRef.GetValue())
					switch sym {
					case sz.SymRefStateInvalid:
						ref.State = ast.RefStateInvalid
					case sz.SymRefStateZettel:
						ref.State = ast.RefStateZettel
					case sz.SymRefStateSelf:
						ref.State = ast.RefStateSelf
					case sz.SymRefStateFound:
						ref.State = ast.RefStateFound
					case sz.SymRefStateBroken:
						ref.State = ast.RefStateBroken
					case sz.SymRefStateHosted:
						ref.State = ast.RefStateHosted
					case sz.SymRefStateBased:
						ref.State = ast.RefStateBased
					case sz.SymRefStateQuery:
						ref.State = ast.RefStateQuery
					case sz.SymRefStateExternal:
						ref.State = ast.RefStateExternal
					}
					return ref
				}
			}
		}
	}
	return nil
}

func handleCite(rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := sz.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			if sKey, isString := sx.GetString(curr.Car()); isString {
				return sxNode{&ast.CiteNode{
					Attrs:   attrs,
					Key:     sKey.GetValue(),
					Inlines: collectInlines(curr.Tail()),
				}}
			}
		}
	}
	log.Println("CITE", rest)
	return rest
}

func handleMark(rest *sx.Pair) sx.Object {
	if rest != nil {
		if sMark, isMarkS := sx.GetString(rest.Car()); isMarkS {
			if curr := rest.Tail(); curr != nil {
				if sSlug, isSlug := sx.GetString(curr.Car()); isSlug {
					if curr = curr.Tail(); curr != nil {
						if sUniq, isUniq := sx.GetString(curr.Car()); isUniq {
							return sxNode{&ast.MarkNode{
								Mark:     sMark.GetValue(),
								Slug:     sSlug.GetValue(),
								Fragment: sUniq.GetValue(),
								Inlines:  collectInlines(curr.Tail()),
							}}
						}
					}
				}
			}
		}
	}
	log.Println("MARK", rest)
	return rest
}

func handleEndnote(rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := sz.GetAttributes(rest.Head())
		return sxNode{&ast.FootnoteNode{
			Attrs:   attrs,
			Inlines: collectInlines(rest.Tail()),
		}}
	}
	log.Println("ENDN", rest)
	return rest
}

func handleFormat(kind ast.FormatKind, rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := sz.GetAttributes(rest.Head())
		return sxNode{&ast.FormatNode{
			Kind:    kind,
			Attrs:   attrs,
			Inlines: collectInlines(rest.Tail()),
		}}
	}
	log.Println("FORM", kind, rest)
	return rest
}

type sxNode struct {
	node ast.Node
}

func (sxNode) IsNil() bool        { return false }
func (sxNode) IsAtom() bool       { return true }
func (n sxNode) String() string   { return fmt.Sprintf("%T/%v", n.node, n.node) }
func (n sxNode) GoString() string { return n.String() }
func (n sxNode) IsEqual(other sx.Object) bool {
	return n.String() == other.String()
}

//-----------------------------------------------------------------------------
// 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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

package ast_test

import (
	"testing"

	"t73f.de/r/zsc/attrs"
	"zettelstore.de/z/ast"
)

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

	for b.Loop() {
		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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

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

import (
	"time"

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/box"
	"zettelstore.de/z/config"
)

// 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 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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

// Package cred provides some function for handling credentials.
package cred

import (
	"bytes"

	"golang.org/x/crypto/bcrypt"

	"t73f.de/r/zsc/domain/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.Write(zid.Bytes())
	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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2023-present Detlef Stern
//-----------------------------------------------------------------------------

package impl

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

	"t73f.de/r/sx"
	"t73f.de/r/sx/sxreader"
)

var encoding = base64.RawURLEncoding

const digestAlg = crypto.SHA384

func sign(claim sx.Object, secret []byte) ([]byte, error) {
	var buf bytes.Buffer
	_, err := sx.Print(&buf, claim)
	if err != nil {
		return nil, err
	}
	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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

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

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

	"t73f.de/r/sx"
	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"t73f.de/r/zsc/sexp"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/auth/policy"
	"zettelstore.de/z/box"
	"zettelstore.de/z/config"
	"zettelstore.de/z/kernel"
)

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(meta.KeyUserID)
	if !ok || subject == "" {
		return nil, ErrNoIdent
	}

	now := time.Now().Round(time.Second)
	sClaim := sx.MakeList(
		sx.Int64(kind),
		sx.MakeString(string(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).GetValue()
	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 = string(ident)
	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(meta.KeyUserRole); ok {
		if ur := val.AsUserRole(); 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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package policy

import (
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/config"
)

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) 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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package policy

import (
	"context"

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/id/idset"
	"t73f.de/r/zsc/domain/meta"
	"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"
)

// 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) (*idset.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.ErrInvalidZid{Zid: zid.String()}
	}
	// 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) 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)
}
func (pp *polBox) ReIndex(ctx context.Context, zid id.Zid) error {
	user := server.GetUser(ctx)
	if pp.policy.CanRefresh(user) {
		// If a user is allowed to refresh all data, it it also allowed to re-index a zettel.
		return pp.box.ReIndex(ctx, zid)
	}
	return box.NewErrNotAllowed("ReIndex", user, zid)
}

//-----------------------------------------------------------------------------
// 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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package policy

import (
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/auth"
)

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) 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(meta.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 != meta.ValueUserRoleOwner && !metaRo.AsBool()
	}

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

//-----------------------------------------------------------------------------
// 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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package policy

import (
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/config"
)

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(meta.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(meta.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{
	meta.KeyID,
	meta.KeyRole,
	meta.KeyUserID,
	meta.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(meta.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) 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(meta.KeyUserRole); ok && val == meta.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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

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

import (
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/config"
)

// 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) 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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package policy

import (
	"fmt"
	"testing"

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/auth"
)

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)
			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(meta.KeyUserRole); ok {
		if ur := val.AsUserRole(); 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 val, ok := m.Get(meta.KeyVisibility); ok {
		return val.AsVisibility()
	}
	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(meta.KeyUserRole, owner.GetDefault(meta.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 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(meta.KeyTitle, "Creator")
	user.Set(meta.KeyUserID, "ceator")
	user.Set(meta.KeyUserRole, meta.ValueUserRoleCreator)
	return user
}
func newReader() *meta.Meta {
	user := meta.New(readerZid)
	user.Set(meta.KeyTitle, "Reader")
	user.Set(meta.KeyUserID, "reader")
	user.Set(meta.KeyUserRole, meta.ValueUserRoleReader)
	return user
}
func newWriter() *meta.Meta {
	user := meta.New(writerZid)
	user.Set(meta.KeyTitle, "Writer")
	user.Set(meta.KeyUserID, "writer")
	user.Set(meta.KeyUserRole, meta.ValueUserRoleWriter)
	return user
}
func newOwner() *meta.Meta {
	user := meta.New(ownerZid)
	user.Set(meta.KeyTitle, "Owner")
	user.Set(meta.KeyUserID, "owner")
	user.Set(meta.KeyUserRole, meta.ValueUserRoleOwner)
	return user
}
func newOwner2() *meta.Meta {
	user := meta.New(owner2Zid)
	user.Set(meta.KeyTitle, "Owner 2")
	user.Set(meta.KeyUserID, "owner-2")
	user.Set(meta.KeyUserRole, meta.ValueUserRoleOwner)
	return user
}
func newZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(meta.KeyTitle, "Any Zettel")
	return m
}
func newPublicZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Public Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityPublic)
	return m
}
func newCreatorZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Creator Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityCreator)
	return m
}
func newLoginZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Login Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityLogin)
	return m
}
func newOwnerZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Owner Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityOwner)
	return m
}
func newExpertZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Expert Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityExpert)
	return m
}
func newRoFalseZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(meta.KeyTitle, "No r/o Zettel")
	m.Set(meta.KeyReadOnly, meta.ValueFalse)
	return m
}
func newRoTrueZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(meta.KeyTitle, "A r/o Zettel")
	m.Set(meta.KeyReadOnly, meta.ValueTrue)
	return m
}
func newRoReaderZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(meta.KeyTitle, "Reader r/o Zettel")
	m.Set(meta.KeyReadOnly, meta.ValueUserRoleReader)
	return m
}
func newRoWriterZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(meta.KeyTitle, "Writer r/o Zettel")
	m.Set(meta.KeyReadOnly, meta.ValueUserRoleWriter)
	return m
}
func newRoOwnerZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(meta.KeyTitle, "Owner r/o Zettel")
	m.Set(meta.KeyReadOnly, meta.ValueUserRoleOwner)
	return m
}
func newUserZettel() *meta.Meta {
	m := meta.New(userZid)
	m.Set(meta.KeyTitle, "Any User")
	m.Set(meta.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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package policy

import "t73f.de/r/zsc/domain/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) 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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

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

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

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/id/idset"
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/query"
	"zettelstore.de/z/zettel"
)

// 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

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

// WriteBox is a box that can create / update zettel content.
type WriteBox interface {
	// 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)

	// 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
}

// 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
	WriteBox

	// FetchZids returns the set of all zettel identifer managed by the box.
	FetchZids(ctx context.Context) (*idset.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

	// ReIndex one zettel to update its index data.
	ReIndex(context.Context, id.Zid) 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 an existing zettel happened
	OnDelete              // A zettel was deleted
)

// 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)

// UpdateNotifier is an UpdateFunc, but with separate values.
type UpdateNotifier func(BaseBox, id.Zid, UpdateReason)

// 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

// DoEnrich determines if the context is not marked to not enrich metadata.
func DoEnrich(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(meta.KeyUserID, "?"), err.User.Zid)
	}
	return fmt.Sprintf(
		"operation %q not allowed for user %v/%v",
		err.Op, err.User.GetDefault(meta.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")

// ErrZettelNotFound is returned if a zettel was not found in the box.
type ErrZettelNotFound struct{ Zid id.Zid }

func (eznf ErrZettelNotFound) Error() string { return "zettel not found: " + eznf.Zid.String() }

// 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")

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

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

//-----------------------------------------------------------------------------
// 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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

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

import (
	"context"
	"net/url"

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"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"
)

func init() {
	manager.Register(
		" comp",
		func(_ *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(context.Context, *compBox) []byte
}{
	id.ZidVersion:         {genVersionBuildM, genVersionBuildC},
	id.ZidHost:            {genVersionHostM, genVersionHostC},
	id.ZidOperatingSystem: {genVersionOSM, genVersionOSC},
	id.ZidLog:             {genLogM, genLogC},
	id.ZidMemory:          {genMemoryM, genMemoryC},
	id.ZidSx:              {genSxM, genSxC},
	// id.ZidHTTP:                 {genHttpM, genHttpC},
	// id.ZidAPI:                  {genApiM, genApiC},
	// id.ZidWebUI:                {genWebUiM, genWebUiC},
	// id.ZidConsole:              {genConsoleM, genConsoleC},
	id.ZidBoxManager: {genManagerM, genManagerC},
	// id.ZidIndex:                {genIndexM, genIndexC},
	// id.ZidQuery:                {genQueryM, genQueryC},
	id.ZidMetadataKey:          {genKeysM, genKeysC},
	id.ZidParser:               {genParserM, genParserC},
	id.ZidStartupConfiguration: {genConfigZettelM, genConfigZettelC},
}

// Get returns the one program box.
func getCompBox(boxNumber int, mf box.Enricher) *compBox {
	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 (cb *compBox) GetZettel(ctx 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(ctx, cb)),
				}, nil
			}
			cb.log.Trace().Msg("GetZettel/NoContent")
			return zettel.Zettel{Meta: m}, nil
		}
	}
	err := box.ErrZettelNotFound{Zid: zid}
	cb.log.Trace().Err(err).Msg("GetZettel/Err")
	return zettel.Zettel{}, err
}

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

func (cb *compBox) DeleteZettel(_ context.Context, zid id.Zid) (err error) {
	if _, ok := myZettel[zid]; ok {
		err = box.ErrReadOnly
	} else {
		err = box.ErrZettelNotFound{Zid: zid}
	}
	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 getTitledMeta(zid id.Zid, title string) *meta.Meta {
	m := meta.New(zid)
	m.Set(meta.KeyTitle, meta.Value(title))
	return m
}

func updateMeta(m *meta.Meta) {
	if _, ok := m.Get(meta.KeySyntax); !ok {
		m.Set(meta.KeySyntax, meta.ValueSyntaxZmk)
	}
	m.Set(meta.KeyRole, meta.ValueRoleConfiguration)
	if _, ok := m.Get(meta.KeyCreated); !ok {
		m.Set(meta.KeyCreated, meta.Value(kernel.Main.GetConfig(kernel.CoreService, kernel.CoreStarted).(string)))
	}
	m.Set(meta.KeyLang, meta.ValueLangEN)
	m.Set(meta.KeyReadOnly, meta.ValueTrue)
	if _, ok := m.Get(meta.KeyVisibility); !ok {
		m.Set(meta.KeyVisibility, meta.ValueVisibilityExpert)
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package compbox

import (
	"bytes"
	"context"

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
)

func genConfigZettelM(zid id.Zid) *meta.Meta {
	if myConfig == nil {
		return nil
	}
	return getTitledMeta(zid, "Zettelstore Startup Configuration")
}

func genConfigZettelC(context.Context, *compBox) []byte {
	var buf bytes.Buffer
	second := false
	for key, val := range myConfig.All() {
		if second {
			buf.WriteByte('\n')
		}
		second = true
		buf.WriteString("; ''")
		buf.WriteString(key)
		buf.WriteString("''")
		if val != "" {
			buf.WriteString("\n: ``")
			for _, r := range val {
				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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package compbox

import (
	"bytes"
	"context"
	"fmt"

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/kernel"
)

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

func genKeysC(context.Context, *compBox) []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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

package compbox

import (
	"bytes"
	"context"

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/kernel"
)

func genLogM(zid id.Zid) *meta.Meta {
	m := getTitledMeta(zid, "Zettelstore Log")
	m.Set(meta.KeySyntax, meta.ValueSyntaxText)
	m.Set(meta.KeyModified, meta.Value(kernel.Main.GetLastLogTime().Local().Format(id.TimestampLayout)))
	return m
}

func genLogC(context.Context, *compBox) []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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

package compbox

import (
	"bytes"
	"context"
	"fmt"

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/kernel"
)

func genManagerM(zid id.Zid) *meta.Meta {
	return getTitledMeta(zid, "Zettelstore Box Manager")
}

func genManagerC(context.Context, *compBox) []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) 2024-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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2024-present Detlef Stern
//-----------------------------------------------------------------------------

package compbox

import (
	"bytes"
	"context"
	"fmt"
	"os"
	"runtime"

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/kernel"
)

func genMemoryM(zid id.Zid) *meta.Meta {
	return getTitledMeta(zid, "Zettelstore Memory")
}

func genMemoryC(context.Context, *compBox) []byte {
	pageSize := os.Getpagesize()
	var m runtime.MemStats
	runtime.GC()
	runtime.ReadMemStats(&m)

	var buf bytes.Buffer
	buf.WriteString("|=Name|=Value>\n")
	fmt.Fprintf(&buf, "|Page Size|%d\n", pageSize)
	fmt.Fprintf(&buf, "|Pages|%d\n", m.HeapSys/uint64(pageSize))
	fmt.Fprintf(&buf, "|Heap Objects|%d\n", m.HeapObjects)
	fmt.Fprintf(&buf, "|Heap Sys (KiB)|%d\n", m.HeapSys/1024)
	fmt.Fprintf(&buf, "|Heap Inuse (KiB)|%d\n", m.HeapInuse/1024)
	fmt.Fprintf(&buf, "|CPUs|%d\n", runtime.NumCPU())
	fmt.Fprintf(&buf, "|Threads|%d\n", runtime.NumGoroutine())
	debug := kernel.Main.GetConfig(kernel.CoreService, kernel.CoreDebug).(bool)
	if debug {
		for i, bysize := range m.BySize {
			fmt.Fprintf(&buf, "|Size %2d: %d|%d - %d → %d\n",
				i, bysize.Size, bysize.Mallocs, bysize.Frees, bysize.Mallocs-bysize.Frees)
		}
	}
	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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

package compbox

import (
	"bytes"
	"context"
	"fmt"
	"slices"
	"strings"

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/parser"
)

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

func genParserC(context.Context, *compBox) []byte {
	var buf bytes.Buffer
	buf.WriteString("|=Syntax<|=Alt. Value(s):|=Text Parser?:|=Text Format?:|=Image Format?:\n")
	syntaxes := parser.GetSyntaxes()
	slices.Sort(syntaxes)
	for _, syntax := range syntaxes {
		info := parser.Get(syntax)
		if info.Name != syntax {
			continue
		}
		altNames := info.AltNames
		slices.Sort(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) 2024-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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2024-present Detlef Stern
//-----------------------------------------------------------------------------

package compbox

import (
	"bytes"
	"context"
	"fmt"

	"t73f.de/r/sx"
	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
)

func genSxM(zid id.Zid) *meta.Meta {
	return getTitledMeta(zid, "Zettelstore Sx Engine")
}

func genSxC(context.Context, *compBox) []byte {
	var buf bytes.Buffer
	buf.WriteString("|=Name|=Value>\n")
	fmt.Fprintf(&buf, "|Symbols|%d\n", sx.MakeSymbol("NIL").Factory().Size())
	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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package compbox

import (
	"context"

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/kernel"
)

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

func genVersionHostM(zid id.Zid) *meta.Meta {
	return getTitledMeta(zid, "Zettelstore Host")
}
func genVersionHostC(context.Context, *compBox) []byte {
	return []byte(kernel.Main.GetConfig(kernel.CoreService, kernel.CoreHostname).(string))
}

func genVersionOSM(zid id.Zid) *meta.Meta {
	return getTitledMeta(zid, "Zettelstore Operating System")
}
func genVersionOSC(context.Context, *compBox) []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...)
}

/*-----------------------------------------------------------------------------
 * 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.
 *
 * SPDX-License-Identifier: EUPL-1.2
 * SPDX-FileCopyrightText: 2020-present Detlef Stern
 *-----------------------------------------------------------------------------
 */

*,*::before,*::after {
    box-sizing: border-box;
  }
  html {
    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; margin:.4em 0 }
  h1 { font-size:1.5em }
  h2 { font-size:1.25em }
  h3 { font-size:1.15em }
  h4 { font-size:1.05em; font-weight: bold }
  h5 { font-size:1.05em }
  h6 { font-size:1.05em; font-weight: lighter }
  p { margin: .5em 0 0 0 }
  p.zs-meta-zettel { margin-top: .5em; margin-left: .5em }
  li,figure,figcaption,dl { margin: 0 }
  dt { margin: .5em 0 0 0 }
  dt+dd { margin-top: 0 }
  dd { margin: .5em 0 0 2em }
  dd > p:first-child { margin: 0 0 0 0 }
  blockquote {
    border-left: .5em solid lightgray;
    padding-left: 1em;
    margin-left: 1em;
    margin-right: 2em;
  }
  blockquote p { margin-bottom: .5em }
  table {
    border-collapse: collapse;
    border-spacing: 0;
    max-width: 100%;
  }
  td, th {text-align: left; padding: .25em .5em;}
  th { font-weight: bold }
  thead th { border-bottom: 2px solid hsl(0, 0%, 70%) }
  td { 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[rel~="external"]::after { content: "➚"; display: inline-block }
  img { max-width: 100% }
  img.right { float: right }
  ol.zs-endnotes {
    padding-top: .5em;
    border-top: 1px solid;
  }
  kbd { font-family:monospace }
  code,pre {
    font-family: monospace;
    font-size: 85%;
  }
  code {
    padding: .1em .2em;
    background: #f0f0f0;
    border: 1px solid #ccc;
    border-radius: .25em;
  }
  pre {
    padding: .5em .7em;
    max-width: 100%;
    overflow: auto;
    border: 1px solid #ccc;
    border-radius: .5em;
    background: #f0f0f0;
  }
  pre code {
    font-size: 95%;
    position: relative;
    padding: 0;
    border: none;
  }
  div.zs-indication {
    padding: .5em .7em;
    max-width: 100%;
    border-radius: .5em;
    border: 1px solid black;
  }
  div.zs-indication p:first-child { margin-top: 0 }
  span.zs-indication {
    border: 1px solid black;
    border-radius: .25em;
    padding: .1rem .2em;
    font-size: 95%;
  }
  .zs-info {
    background-color: lightblue;
    padding: .5em 1em;
  }
  .zs-warning {
    background-color: lightyellow;
    padding: .5em 1em;
  }
  .zs-error {
    background-color: lightpink;
    border-style: none !important;
    font-weight: bold;
  }
  td.left, th.left { text-align:left }
  td.center, th.center { text-align:center }
  td.right, th.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: .2em }
  .zs-meta {
    font-size:.75rem;
    color:#444;
    margin-bottom:1em;
  }
  .zs-meta a { color:#444 }
  h1+.zs-meta { margin-top:-1em }
  nav > details { margin-top:1em }
  details > summary {
    width: 100%;
    background-color: #eee;
    font-family:sans-serif;
  }
  details > ul {
    margin-top:0;
    padding-left:2em;
    background-color: #eee;
  }
  footer { padding: 0 1em }
  @media (prefers-reduced-motion: reduce) {
    * {
      animation-duration: 0.01ms !important;
      animation-iteration-count: 1 !important;
      transition-duration: 0.01ms !important;
      scroll-behavior: auto !important;
    }
  }

;;;----------------------------------------------------------------------------
;;; 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.
;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

`(@@@@
(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)))
  ,@(ROLE-DEFAULT-meta (current-binding))
  (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"))
        ,@list-urls
        ,@(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)
       )))
    )
    (search (form (@ (action ,search-url))
      (input (@ (type "search") (inputmode "search") (name ,query-key-query)
                (title "General search field, with same behaviour as search field in search result list")
                (placeholder "Search..") (dir "auto")))))
  )
  (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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

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

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

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"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"
)

func init() {
	manager.Register(
		" const",
		func(_ *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 (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
	}
	err := box.ErrZettelNotFound{Zid: zid}
	cb.log.Trace().Err(err).Msg("GetZettel/Err")
	return zettel.Zettel{}, err
}

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

func (cb *constBox) DeleteZettel(_ context.Context, zid id.Zid) (err error) {
	if _, ok := cb.zettel[zid]; ok {
		err = box.ErrReadOnly
	} else {
		err = box.ErrZettelNotFound{Zid: zid}
	}
	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.ZidConfiguration: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Runtime Configuration",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxNone,
			meta.KeyCreated:    "20200804111624",
			meta.KeyVisibility: meta.ValueVisibilityOwner,
		},
		zettel.NewContent(nil)},
	id.ZidLicense: {
		constHeader{
			meta.KeyTitle:      "Zettelstore License",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxText,
			meta.KeyCreated:    "20210504135842",
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyModified:   "20220131153422",
			meta.KeyReadOnly:   meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityPublic,
		},
		zettel.NewContent(contentLicense)},
	id.ZidAuthors: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Contributors",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxZmk,
			meta.KeyCreated:    "20210504135842",
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyReadOnly:   meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityLogin,
		},
		zettel.NewContent(contentContributors)},
	id.ZidDependencies: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Dependencies",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxZmk,
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyReadOnly:   meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityPublic,
			meta.KeyCreated:    "20210504135842",
			meta.KeyModified:   "20250212202400",
		},
		zettel.NewContent(contentDependencies)},
	id.ZidBaseTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Base HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20230510155100",
			meta.KeyModified:   "20241227212000",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentBaseSxn)},
	id.ZidLoginTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Login Form HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20200804111624",
			meta.KeyModified:   "20240219145200",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentLoginSxn)},
	id.ZidZettelTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Zettel HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20230510155300",
			meta.KeyModified:   "20250214153100",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentZettelSxn)},
	id.ZidInfoTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Info HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20200804111624",
			meta.KeyModified:   "20241127170500",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentInfoSxn)},
	id.ZidFormTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Form HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20200804111624",
			meta.KeyModified:   "20240219145200",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentFormSxn)},
	id.ZidDeleteTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Delete HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20200804111624",
			meta.KeyModified:   "20241127170530",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentDeleteSxn)},
	id.ZidListTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore List Zettel HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20230704122100",
			meta.KeyModified:   "20240219145200",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentListZettelSxn)},
	id.ZidErrorTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Error HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20210305133215",
			meta.KeyModified:   "20240219145200",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentErrorSxn)},
	id.ZidSxnStart: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Sxn Start Code",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20230824160700",
			meta.KeyModified:   "20240219145200",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
			meta.KeyPrecursor:  id.ZidSxnBase.String(),
		},
		zettel.NewContent(contentStartCodeSxn)},
	id.ZidSxnBase: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Sxn Base Code",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20230619132800",
			meta.KeyModified:   "20241118173500",
			meta.KeyReadOnly:   meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
			meta.KeyPrecursor:  id.ZidSxnPrelude.String(),
		},
		zettel.NewContent(contentBaseCodeSxn)},
	id.ZidSxnPrelude: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Sxn Prelude",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20231006181700",
			meta.KeyModified:   "20240222121200",
			meta.KeyReadOnly:   meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentPreludeSxn)},
	id.ZidBaseCSS: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Base CSS",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxCSS,
			meta.KeyCreated:    "20200804111624",
			meta.KeyModified:   "20240827143500",
			meta.KeyVisibility: meta.ValueVisibilityPublic,
		},
		zettel.NewContent(contentBaseCSS)},
	id.ZidUserCSS: {
		constHeader{
			meta.KeyTitle:      "Zettelstore User CSS",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxCSS,
			meta.KeyCreated:    "20210622110143",
			meta.KeyVisibility: meta.ValueVisibilityPublic,
		},
		zettel.NewContent([]byte("/* User-defined CSS */"))},
	id.ZidEmoji: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Generic Emoji",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxGif,
			meta.KeyReadOnly:   meta.ValueTrue,
			meta.KeyCreated:    "20210504175807",
			meta.KeyVisibility: meta.ValueVisibilityPublic,
		},
		zettel.NewContent(contentEmoji)},
	id.ZidTOCListsMenu: {
		constHeader{
			meta.KeyTitle:      "Lists Menu",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxZmk,
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyCreated:    "20241223205400",
			meta.KeyVisibility: meta.ValueVisibilityPublic,
		},
		zettel.NewContent(contentMenuListsZettel)},
	id.ZidTOCNewTemplate: {
		constHeader{
			meta.KeyTitle:      "New Menu",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxZmk,
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyCreated:    "20210217161829",
			meta.KeyModified:   "20231129111800",
			meta.KeyVisibility: meta.ValueVisibilityCreator,
		},
		zettel.NewContent(contentMenuNewZettel)},
	id.ZidTemplateNewZettel: {
		constHeader{
			meta.KeyTitle:                 "New Zettel",
			meta.KeyRole:                  meta.ValueRoleConfiguration,
			meta.KeySyntax:                meta.ValueSyntaxZmk,
			meta.KeyCreated:               "20201028185209",
			meta.KeyModified:              "20230929132900",
			meta.NewPrefix + meta.KeyRole: meta.ValueRoleZettel,
			meta.KeyVisibility:            meta.ValueVisibilityCreator,
		},
		zettel.NewContent(nil)},
	id.ZidTemplateNewRole: {
		constHeader{
			meta.KeyTitle:                  "New Role",
			meta.KeyRole:                   meta.ValueRoleConfiguration,
			meta.KeySyntax:                 meta.ValueSyntaxZmk,
			meta.KeyCreated:                "20231129110800",
			meta.NewPrefix + meta.KeyRole:  meta.ValueRoleRole,
			meta.NewPrefix + meta.KeyTitle: "",
			meta.KeyVisibility:             meta.ValueVisibilityCreator,
		},
		zettel.NewContent(nil)},
	id.ZidTemplateNewTag: {
		constHeader{
			meta.KeyTitle:                  "New Tag",
			meta.KeyRole:                   meta.ValueRoleConfiguration,
			meta.KeySyntax:                 meta.ValueSyntaxZmk,
			meta.KeyCreated:                "20230929132400",
			meta.NewPrefix + meta.KeyRole:  meta.ValueRoleTag,
			meta.NewPrefix + meta.KeyTitle: "#",
			meta.KeyVisibility:             meta.ValueVisibilityCreator,
		},
		zettel.NewContent(nil)},
	id.ZidTemplateNewUser: {
		constHeader{
			meta.KeyTitle:                       "New User",
			meta.KeyRole:                        meta.ValueRoleConfiguration,
			meta.KeySyntax:                      meta.ValueSyntaxNone,
			meta.KeyCreated:                     "20201028185209",
			meta.NewPrefix + meta.KeyCredential: "",
			meta.NewPrefix + meta.KeyUserID:     "",
			meta.NewPrefix + meta.KeyUserRole:   meta.ValueUserRoleReader,
			meta.KeyVisibility:                  meta.ValueVisibilityOwner,
		},
		zettel.NewContent(nil)},
	id.ZidRoleZettelZettel: {
		constHeader{
			meta.KeyTitle:      meta.ValueRoleZettel,
			meta.KeyRole:       meta.ValueRoleRole,
			meta.KeySyntax:     meta.ValueSyntaxZmk,
			meta.KeyCreated:    "20231129161400",
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyVisibility: meta.ValueVisibilityLogin,
		},
		zettel.NewContent(contentRoleZettel)},
	id.ZidRoleConfigurationZettel: {
		constHeader{
			meta.KeyTitle:      meta.ValueRoleConfiguration,
			meta.KeyRole:       meta.ValueRoleRole,
			meta.KeySyntax:     meta.ValueSyntaxZmk,
			meta.KeyCreated:    "20241213103100",
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyVisibility: meta.ValueVisibilityLogin,
		},
		zettel.NewContent(contentRoleConfiguration)},
	id.ZidRoleRoleZettel: {
		constHeader{
			meta.KeyTitle:      meta.ValueRoleRole,
			meta.KeyRole:       meta.ValueRoleRole,
			meta.KeySyntax:     meta.ValueSyntaxZmk,
			meta.KeyCreated:    "20231129162900",
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyVisibility: meta.ValueVisibilityLogin,
		},
		zettel.NewContent(contentRoleRole)},
	id.ZidRoleTagZettel: {
		constHeader{
			meta.KeyTitle:      meta.ValueRoleTag,
			meta.KeyRole:       meta.ValueRoleRole,
			meta.KeySyntax:     meta.ValueSyntaxZmk,
			meta.KeyCreated:    "20231129162000",
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyVisibility: meta.ValueVisibilityLogin,
		},
		zettel.NewContent(contentRoleTag)},
	id.ZidAppDirectory: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Application Directory",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxNone,
			meta.KeyLang:       meta.ValueLangEN,
			meta.KeyCreated:    "20240703235900",
			meta.KeyVisibility: meta.ValueVisibilityLogin,
		},
		zettel.NewContent(nil)},
	id.ZidDefaultHome: {
		constHeader{
			meta.KeyTitle:    "Home",
			meta.KeyRole:     meta.ValueRoleZettel,
			meta.KeySyntax:   meta.ValueSyntaxZmk,
			meta.KeyLang:     meta.ValueLangEN,
			meta.KeyCreated:  "20210210190757",
			meta.KeyModified: "20241216105800",
		},
		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 delete.sxn
var contentDeleteSxn []byte

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

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

//go:embed start.sxn
var contentStartCodeSxn []byte

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

//go:embed prelude.sxn
var contentPreludeSxn []byte

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

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

//go:embed menu_lists.zettel
var contentMenuListsZettel []byte

//go:embed menu_new.zettel
var contentMenuNewZettel []byte

//go:embed rolezettel.zettel
var contentRoleZettel []byte

//go:embed roleconfiguration.zettel
var contentRoleConfiguration []byte

//go:embed rolerole.zettel
var contentRoleRole []byte

//go:embed roletag.zettel
var contentRoleTag []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

;;;----------------------------------------------------------------------------
;;; 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.
;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

`(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, SxWebs, Webs, Zero, Zettelstore-Client
These are companion projects, written by the main developer of Zettelstore.
They are published under the same license, [[EUPL v1.2, or later|00000000000004]].

; URL & Source Sx
: [[https://t73f.de/r/sx]]
; URL & Source SxWebs
: [[https://t73f.de/r/sxwebs]]
; URL & Source Webs
: [[https://t73f.de/r/webs]]
; URL & Source Zero
: [[https://t73f.de/r/zero]]
; URL & Source Zettelstore-Client
: [[https://t73f.de/r/zsc]]
; License:
: European Union Public License, version 1.2 (EUPL v1.2), or later.

;;;----------------------------------------------------------------------------
;;; 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.
;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

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

;;;----------------------------------------------------------------------------
;;; 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.
;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

`(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")
              (title "Title of this zettel")
              (placeholder "Title..") (value ,meta-title) (dir "auto") (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") (pattern "\\w*") (id "zs-role") (name "role")
              (title "One word, letters and digits, but no spaces, to set the main role of the zettel.")
              (placeholder "role..") (value ,meta-role) (dir "auto")
      ,@(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")
              (title "Tags/keywords to categorize the zettel. Each tags is a word that begins with a '#' character; they are separated by spaces")
              (placeholder "#tag") (value ,meta-tags) (dir "auto"))))
  (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")
                 (title "Additional metadata about the zettel")
                 (placeholder "metakey: metavalue") (dir "auto")) ,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") (pattern "\\w*") (id "zs-syntax") (name "syntax")
              (title "Syntax/format of zettel content below, one word, letters and digits, no spaces.")
              (placeholder "syntax..") (value ,meta-syntax) (dir "auto")
      ,@(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")
                   (title "Zettel content, according to the given syntax")
                   (placeholder "Zettel content..") (dir "auto")) ,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 latest information about Zettelstore at [[https://zettelstore.de]].
Check this website regularly for [[updates|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 updating.
Sometimes, you have to edit some of your Zettelstore-related zettel before updating.
Since Zettelstore is currently in a development state, every update 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 did before that error occurs
and what you 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 so, 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.

;;;----------------------------------------------------------------------------
;;; 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.
;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

`(article
  (header (h1 "Information for Zettel " ,zid)
    (p
      (a (@ (href ,web-url)) "Web")
      (@H " · ") (a (@ (href ,context-url)) "Context")
      (@H " / ") (a (@ (href ,context-full-url)) "Full")
      ,@(if (bound? 'edit-url) `((@H " · ") (a (@ (href ,edit-url)) "Edit")))
      ,@(ROLE-DEFAULT-actions (current-binding))
      ,@(if (bound? 'reindex-url) `((@H " · ") (a (@ (href ,reindex-url)) "Reindex")))
      ,@(if (bound? 'delete-url) `((@H " · ") (a (@ (href ,delete-url)) "Delete")))
    )
  )
  (h2 "Interpreted Metadata")
  (table ,@(map wui-info-meta-table-row metadata))
  (h2 "References")
  ,@(if local-links `((h3 "Local")    (ul ,@(map wui-local-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

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                          Licensed under the EUPL

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— this licence shall be governed by Belgian law if the Licensor has no seat,
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                                  Appendix


‘Compatible Licences’ according to Article 5 EUPL are:

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

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

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

;;;----------------------------------------------------------------------------
;;; 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.
;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

`(article
  (header (h1 ,heading))
  (search (form (@ (action ,search-url))
    (input (@ (class "zs-input") (type "search") (inputmode "search") (name ,query-key-query)
              (title "Contains the search that leads to the list below. You're allowed to modify it")
              (placeholder "Search..") (value ,query-value) (dir "auto")))))
  ,@(if (bound? 'tag-zettel)
     `((p (@ (class "zs-meta-zettel")) "Tag zettel: " ,@tag-zettel))
    )
  ,@(if (bound? 'create-tag-zettel)
     `((p (@ (class "zs-meta-zettel")) "Create tag zettel: " ,@create-tag-zettel))
    )
  ,@(if (bound? 'role-zettel)
     `((p (@ (class "zs-meta-zettel")) "Role zettel: " ,@role-zettel))
    )
  ,@(if (bound? 'create-role-zettel)
     `((p (@ (class "zs-meta-zettel")) "Create role zettel: " ,@create-role-zettel))
    )
  ,@content
  ,@endnotes
  (form (@ (action ,(if (bound? 'create-url) create-url)))
      ,(if (bound? 'data-url)
          `(@L "Other encodings"
               ,(if (> num-entries 3) `(@L " of these " ,num-entries " entries: ") ": ")
               (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")))
        )
      )
  )
)

;;;----------------------------------------------------------------------------
;;; 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.
;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

`(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 entries of the ""Lists"" menu.

* [[List Zettel|query:]]
* [[List Roles|query:|role]]
* [[List Tags|query:|tags]]

An additional ""Refresh"" menu item is automatically added if appropriate.

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 Role|00000000090004]]
* [[New Tag|00000000090003]]
* [[New User|00000000090002]]

;;;----------------------------------------------------------------------------
;;; 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.
;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

;;; This zettel contains sxn definitions that are independent of specific
;;; subsystems, such as WebUI, API, or other. It just contains generic code to
;;; be used in all places. It asumes that the symbols NIL and T are defined.

;; not macro
(defmacro not (x) `(if ,x NIL T))

;; not= macro, to negate an equivalence
(defmacro not= args `(not (= ,@args)))

;; let* macro
;;
;; (let* (BINDING ...) EXPR ...), where SYMBOL may occur in later bindings.
(defmacro let* (bindings . body)
    (if (null? bindings)
        `(begin ,@body)
        `(let ((,(caar bindings) ,(cadar bindings)))
               (let* ,(cdr bindings) ,@body))))

;; cond macro
;;
;; (cond ((COND EXPR) ...))
(defmacro cond clauses
    (if (null? clauses)
        ()
        (let* ((clause (car clauses))
               (the-cond (car clause)))
              (if (= the-cond T)
                  `(begin ,@(cdr clause))
                  `(if ,the-cond
                       (begin ,@(cdr clause))
                       (cond ,@(cdr clauses)))))))

;; and macro
;;
;; (and EXPR ...)
(defmacro and args
    (cond ((null? args)       T)
          ((null? (cdr args)) (car args))
          (T                  `(if ,(car args) (and ,@(cdr args))))))


;; or macro
;;
;; (or EXPR ...)
(defmacro or args
    (cond ((null? args)       NIL)
          ((null? (cdr args)) (car args))
          (T                  `(if ,(car args) T (or ,@(cdr args))))))

Zettel with role ""configuration"" are used within Zettelstore to manage and to show the current configuration of the software.

Typically, there are some public zettel that show the license of this software, its dependencies.
There is some CSS code to make the default web user interface a litte bit nicer.
The default image to signal a broken image can be configured too.

Other zettel are only visible if an user has authenticated itself, or if there is no authentication enabled.
In this case, one additional configuration zettel is the zettel containing the version number of this software.
Other zettel are showing the supported metadata keys and supported syntax values.
Zettel that allow to configure the menu of template to create new zettel are also using the role ""configuration"".

Most important is the zettel that contains the runtime configuration.
You may change its metadata value to change the behaviour of the software.

One configuration is the ""expert mode"".
If enabled, and if you are authorized to see them, you will discover some more zettel.
For example, HTML templates to customize the default web user interface, to show the application log, to see statistics about zettel boxes, to show the host name and it operating system, and many more.

You are allowed to add your own configuration zettel, for example if you want to customize the look and feel of zettel by placing relevant data into your own zettel.

By default, user zettel (for authentification) use also the role ""configuration"".
However, you are allowed to change this.

A zettel with the role ""role"" describes a specific role.
The described role must be the title of such a zettel.

This zettel is such a zettel, as it describes the meaning of the role ""role"".
Therefore it has the title ""role"" too.
If you like, this zettel is a meta-role.

You are free to create your own role-describing zettel.
For example, you want to document the intended meaning of the role.
You might also be interested to describe needed metadata so that some software is enabled to analyse or to process your zettel.

A zettel with role ""tag"" is a zettel that describes specific tag.
The tag name must be the title of such a zettel.

Such zettel are similar to this specific zettel: this zettel describes zettel with a role ""tag"".
These zettel with the role ""tag"" describe specific tags.
These might form a hierarchy of meta-tags (and meta-roles).

A zettel with the role ""zettel"" is typically used to document your own thoughts.
Such zettel are the main reason to use the software Zettelstore.

The only predefined zettel with the role ""zettel"" is the [[default home zettel|00010000000000]], which contains some welcome information.

You are free to change this.
In this case you should modify this zettel too, so that it reflects your own use of zettel with the role ""zettel"".

;;;----------------------------------------------------------------------------
;;; 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.
;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

;;; This zettel is the start of the loading sequence for Sx code used in the
;;; Zettelstore. Via the precursor metadata, dependend zettel are evaluated
;;; before this zettel. You must always depend, directly or indirectly on the
;;; "Zettelstore Sxn Base Code" zettel. It provides the base definitions.

;;;----------------------------------------------------------------------------
;;; 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.
;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

;; Contains WebUI specific code, but not related to a specific template.

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

;; wui-info-meta-table-row takes a pair and translates it into a HTML table row
;; with two columns.
(defun wui-info-meta-table-row (p)
    `(tr (td (@ (class zs-info-meta-key)) ,(car p)) (td (@ (class zs-info-meta-value)) ,(cdr p))))

;; wui-local-link translates a local link into HTML.
(defun wui-local-link (l) `(li (a (@ (href ,l )) ,l)))

;; wui-link takes a link (title . url) and returns a HTML reference.
(defun 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.
(defun 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.
(defun 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.
(defun wui-item-popup-link (e)
    `(li (a (@ (href ,e) (target "_blank") (rel "external noreferrer")) ,e)))

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

;; wui-datalist returns a HTML datalist with the given HTML identifier and a
;; list of values.
(defun 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. 
(defun 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.
(defun 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.
(defun wui-enc-matrix (matrix)
    `(table
      ,@(map
         (lambda (row) `(tr (th ,(car row)) ,@(map wui-tdata-link (cdr row))))
         matrix)))

;; CSS-ROLE-map is a mapping (pair list, assoc list) of role names to zettel
;; identifier. It is used in the base template to update the metadata of the
;; HTML page to include some role specific CSS code.
;; Referenced in function "ROLE-DEFAULT-meta".
(defvar CSS-ROLE-map '())

;; ROLE-DEFAULT-meta returns some metadata for the base template. Any role
;; specific code should include the returned list of this function.
(defun ROLE-DEFAULT-meta (binding)
    `(,@(let* ((meta-role (binding-lookup 'meta-role binding))
               (entry (assoc CSS-ROLE-map meta-role)))
              (if (pair? entry)
                  `((link (@ (rel "stylesheet") (href ,(zid-content-path (cdr entry))))))
              )
        )
    )
)

;; ACTION-SEPARATOR defines a HTML value that separates actions links.
(defvar ACTION-SEPARATOR '(@H " · "))

;; ROLE-DEFAULT-actions returns the default text for actions.
(defun ROLE-DEFAULT-actions (binding)
    `(,@(let ((copy-url (binding-lookup 'copy-url binding)))
             (if (defined? copy-url) `((@H " · ") (a (@ (href ,copy-url)) "Copy"))))
      ,@(let ((version-url (binding-lookup 'version-url binding)))
             (if (defined? version-url) `((@H " · ") (a (@ (href ,version-url)) "Version"))))
      ,@(let ((sequel-url (binding-lookup 'sequel-url binding)))
             (if (defined? sequel-url) `((@H " · ") (a (@ (href ,sequel-url)) "Sequel"))))
      ,@(let ((folge-url (binding-lookup 'folge-url binding)))
             (if (defined? folge-url) `((@H " · ") (a (@ (href ,folge-url)) "Folge"))))
    )
)

;; ROLE-tag-actions returns an additional action "Zettel" for zettel with role "tag".
(defun ROLE-tag-actions (binding)
    `(,@(ROLE-DEFAULT-actions binding)
      ,@(let ((title (binding-lookup 'title binding)))
             (if (and (defined? title) title)
                 `(,ACTION-SEPARATOR (a (@ (href ,(query->url (concat "tags:" title)))) "Zettel"))
             )
        )
    )
)

;; ROLE-role-actions returns an additional action "Zettel" for zettel with role "role".
(defun ROLE-role-actions (binding)
    `(,@(ROLE-DEFAULT-actions binding)
      ,@(let ((title (binding-lookup 'title binding)))
             (if (and (defined? title) title)
                 `(,ACTION-SEPARATOR (a (@ (href ,(query->url (concat "role:" title)))) "Zettel"))
             )
        )
    )
)

;; ROLE-DEFAULT-heading returns the default text for headings, below the
;; references of a zettel. In most cases it should be called from an
;; overwriting function.
(defun ROLE-DEFAULT-heading (binding)
    `(,@(let ((meta-url (binding-lookup 'meta-url binding)))
           (if (defined? meta-url) `((br) "URL: " ,(url-to-html meta-url))))
      ,@(let ((urls (binding-lookup 'urls binding)))
           (if (defined? urls)
               (map (lambda (u) `(@L (br) ,(car u) ": " ,(url-to-html (cdr u)))) urls)
           )
        )
      ,@(let ((meta-author (binding-lookup 'meta-author binding)))
           (if (and (defined? meta-author) meta-author) `((br) "By " ,meta-author)))
    )
)

;;;----------------------------------------------------------------------------
;;; 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.
;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

`(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))
      ,@(ROLE-DEFAULT-actions (current-binding))
      ,@(if superior-refs `((br) "Superior: " ,superior-refs))
      ,@(if predecessor-refs `((br) "Predecessor: " ,predecessor-refs))
      ,@(if prequel-refs `((br) "Prequel: " ,prequel-refs))
      ,@(if precursor-refs `((br) "Precursor: " ,precursor-refs))
      ,@(ROLE-DEFAULT-heading (current-binding))
    )
  )
  ,@content
  ,endnotes
  ,@(if (or folge-links sequel-links back-links successor-links subordinate-links)
    `((nav
      ,@(if folge-links `((details (@ (,folge-open)) (summary "Folgezettel") (ul ,@(map wui-item-link folge-links)))))
      ,@(if sequel-links `((details (@ (,sequel-open)) (summary "Sequel") (ul ,@(map wui-item-link sequel-links)))))
      ,@(if successor-links `((details (@ (,successor-open)) (summary "Successors") (ul ,@(map wui-item-link successor-links)))))
      ,@(if subordinate-links `((details (@ (,subordinate-open)) (summary "Subordinates") (ul ,@(map wui-item-link subordinate-links)))))
      ,@(if back-links `((details (@ (,back-open)) (summary "Incoming") (ul ,@(map wui-item-link back-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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

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

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

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"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"
)

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 range 2 {
		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 := range dp.fSrvs {
		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.Error().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, reason box.UpdateReason) {
	if notify := dp.cdata.Notify; notify != nil {
		dp.log.Trace().Zid(zid).Uint("reason", uint64(reason)).Msg("notifyChanged")
		notify(dp, zid, reason)
	}
}

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, box.OnZettel)
	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.ErrZettelNotFound{Zid: zid}
	}
	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.ErrInvalidZid{Zid: zid.String()}
	}
	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, box.OnZettel)
	}
	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) 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.ErrZettelNotFound{Zid: zid}
	}
	err := dp.dirSrv.DeleteDirEntry(zid)
	if err != nil {
		return nil
	}
	err = dp.srvDeleteZettel(ctx, entry, zid)
	if err == nil {
		dp.notifyChanged(zid, box.OnDelete)
	}
	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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

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 := range uint32(1500) {
		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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package dirbox

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

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"t73f.de/r/zsc/input"
	"zettelstore.de/z/box/filebox"
	"zettelstore.de/z/box/notify"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/zettel"
)

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

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

type fileCmd interface {
	run(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(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 == "" {
			err = fmt.Errorf("no meta, no content in getMeta, zid=%v", zid)
		} else 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(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 == "" {
			err = fmt.Errorf("no meta, no content in getMetaContent, zid=%v", zid)
		} else 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(dirPath string) {
	var err error
	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 == "" {
			err = fmt.Errorf("no meta, no content in setZettel, zid=%v", zid)
		} else {
			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
	}
	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(dirPath string) {
	var err error

	entry := cmd.entry
	contentName := entry.ContentName
	contentPath := filepath.Join(dirPath, contentName)
	if metaName := entry.MetaName; metaName == "" {
		if contentName == "" {
			err = fmt.Errorf("no meta, no content in deleteZettel, zid=%v", entry.Zid)
		} else {
			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,
	)
}

// fileMode to create a new file: user, group, and all are allowed to read and write.
//
// If you want to forbid others or the group to read or to write, you must set
// umask(1) accordingly.
const fileMode os.FileMode = 0666 //

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

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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

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

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

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager"
	"zettelstore.de/z/kernel"
)

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]meta.Value{
	"htm": "html",
}

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

// CalcDefaultMeta returns metadata with default values for the given entry.
func CalcDefaultMeta(zid id.Zid, ext string) *meta.Meta {
	m := meta.New(zid)
	m.Set(meta.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(meta.KeySyntax); !ok || syntax == "" {
			dm := CalcDefaultMeta(zid, ext)
			syntax, ok = dm.Get(meta.KeySyntax)
			if !ok {
				panic("Default meta must contain syntax")
			}
			m.Set(meta.KeySyntax, syntax)
		}
	}

	if len(uselessFiles) > 0 {
		m.Set(meta.KeyUselessFiles, meta.Value(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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

package filebox

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

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"t73f.de/r/zsc/input"
	"zettelstore.de/z/box"
	"zettelstore.de/z/box/notify"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/query"
	"zettelstore.de/z/zettel"
)

type zipBox struct {
	log      *logger.Logger
	number   int
	name     string
	enricher box.Enricher
	notify   box.UpdateNotifier
	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 (zb *zipBox) GetZettel(_ context.Context, zid id.Zid) (zettel.Zettel, error) {
	entry := zb.dirSrv.GetDirEntry(zid)
	if !entry.IsValid() {
		return zettel.Zettel{}, box.ErrZettelNotFound{Zid: zid}
	}
	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 == "" {
			err = fmt.Errorf("no meta, no content in getZettel, zid=%v", zid)
			return zettel.Zettel{}, err
		}
		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) 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.ErrZettelNotFound{Zid: zid}
	}
	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 == "" {
			err = fmt.Errorf("no meta, no content in getMeta, zid=%v", zid)
		} else 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.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

package box

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

	"t73f.de/r/zsc/domain/id"
)

// GetNewZid calculates a new and unused zettel identifier, based on the current date and time.
func GetNewZid(testZid func(id.Zid) (bool, error)) (id.Zid, error) {
	withSeconds := false
	for range 90 { // 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, minVal, defVal, maxVal int) int {
	sVal := u.Query().Get(key)
	if sVal == "" {
		return defVal
	}
	iVal, err := strconv.Atoi(sVal)
	if err != nil {
		return defVal
	}
	if iVal < minVal {
		return minVal
	}
	if iVal > maxVal {
		return maxVal
	}
	return iVal
}