Zettelstore

0.4
0.5.1

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

// InlineEmbedNode is a node that specifies some embeddings in inline mode.
// It is abstract, b/c there are different concrete type implementations.
type InlineEmbedNode interface {
	InlineNode
	inlineEmbedNode()
}

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

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

package ast

import "zettelstore.de/c/zjson"
import "zettelstore.de/c/attrs"

// Definition of Block nodes.

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

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

	Inlines InlineSlice
}

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

// NewParaNode creates an empty ParaNode.
func NewParaNode() *ParaNode { return &ParaNode{} }

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


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

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

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

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

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

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

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

// Supported syntax values for VerbatimEval.
const (
	VerbatimEvalSyntaxDraw = "draw"
)

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

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

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

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

}

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

// HeadingNode stores the heading text and level.
type HeadingNode struct {
	Level    int
	Inlines  InlineSlice // Heading text, possibly formatted
	Attrs    attrs.Attributes
	Slug     string      // Heading text, normalized
	Fragment string      // Heading text, suitable to be used as an unique URL fragment
	Attrs    zjson.Attributes
	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) {
func (hn *HeadingNode) WalkChildren(v Visitor) { Walk(v, &hn.Inlines) }
	Walk(v, &hn.Inlines)
}

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

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

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

// Values for ListCode
const (

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

package ast

import (
	"unicode/utf8"

	"zettelstore.de/c/zjson"
	"zettelstore.de/c/attrs"
)

// Definitions of inline nodes.

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

// 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.
	Inlines InlineSlice // The text associated with the link.
	Attrs   zjson.Attributes // Optional attributes
}

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.
	Inlines InlineSlice      // Optional text associated with the image.
	Attrs   zjson.Attributes // Optional attributes
	Syntax  string           // Syntax of referenced material, if known
	Inlines InlineSlice      // Optional text associated with the image.
}

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

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

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

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

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

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

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

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

	}
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

package ast

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

package ast_test

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
// Copyright (c) 2021-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

package ast

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

package ast_test

import (
	"testing"

	"zettelstore.de/c/zjson"
	"zettelstore.de/c/attrs"
	"zettelstore.de/z/ast"
)

func BenchmarkWalk(b *testing.B) {
	root := ast.BlockSlice{
		&ast.HeadingNode{
			Inlines: ast.CreateInlineSliceFromWords("A", "Simple", "Heading"),

		},
		&ast.ParaNode{
			Inlines: ast.CreateInlineSliceFromWords("This", "is", "some", "intermediate", "text."),
		},
		ast.CreateParaNode(
			&ast.FormatNode{
				Kind: ast.FormatEmph,
				Attrs: zjson.Attributes(map[string]string{
				Attrs: attrs.Attributes(map[string]string{
					"":      "class",
					"color": "green",
				}),
				Inlines: ast.CreateInlineSliceFromWords("This", "is", "some", "emphasized", "text."),
			},
			&ast.SpaceNode{Lexeme: " "},
			&ast.LinkNode{

//-----------------------------------------------------------------------------
// Copyright (c) 2021 Detlef Stern
// Copyright (c) 2021-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package impl provides services for authentification / authorization.

    clear: both;
    visibility: hidden;
  }
  main form div { margin: .5em 0 0 0 }
  input { font-family: monospace }
  input[type="submit"],button,select { font: inherit }
  label { font-family: sans-serif; font-size:.9rem }
  label::after { content:":" }
  textarea {
    font-family: monospace;
    resize: vertical;
    width: 100%;
  }
  .zs-input {
    padding: .5em;
    display:block;
    border:none;
    border-bottom:1px solid #ccc;
    width:100%;
  }
  .zs-button {
    float:right;
  input.zs-primary { float:right }
    margin: .5em 0 .5em 1em;
  }
  input.zs-secondary { float:left }
  a:not([class]) { text-decoration-skip-ink: auto }
  a.broken { text-decoration: line-through }
  img { max-width: 100% }
  img.right { float: right }
  ol.endnotes {
  ol.zs-endnotes {
    padding-top: .5rem;
    border-top: 1px solid;
  }
  kbd { font-family:monospace }
  code,pre {
    font-family: monospace;
    font-size: 85%;

<!DOCTYPE html>
<html{{#Lang}} 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">
{{{MetaHeader}}}
<link rel="stylesheet" href="{{{CSSBaseURL}}}">
<link rel="stylesheet" href="{{{CSSUserURL}}}">
{{#CSSRoleURL}}<link rel="stylesheet" href="{{{CSSRoleURL}}}">{{/CSSRoleURL}}
<title>{{Title}}</title>
</head>
<body>
<nav class="zs-menu">
<a href="{{{HomeURL}}}">Home</a>
{{#WithUser}}
<div class="zs-dropdown">

<form action="{{{SearchURL}}}">
<input type="text" placeholder="Search.." name="{{QueryKeySearch}}">
</form>
</nav>
<main class="content">
{{{Content}}}
</main>
{{#FooterHTML}}
<footer>
{{#FooterHTML}}<footer>{{{FooterHTML}}}</footer>{{/FooterHTML}}
{{#DebugMode}}<div><b>WARNING: Debug mode is enabled. DO NOT USE IN PRODUCTION!</b></div>{{/DebugMode}}
</body>
{{{FooterHTML}}}
</footer>
</html>
{{/FooterHTML}}

		constHeader{
			api.KeyTitle:      "Zettelstore User CSS",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     "css",
			api.KeyVisibility: api.ValueVisibilityPublic,
		},
		domain.NewContent([]byte("/* User-defined CSS */"))},
	id.RoleCSSMapZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Role to CSS Map",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     api.ValueSyntaxNone,
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(nil)},
	id.EmojiZid: {
		constHeader{
			api.KeyTitle:      "Generic Emoji",
			api.KeyTitle:      "Zettelstore Generic Emoji",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     api.ValueSyntaxGif,
			api.KeyReadOnly:   api.ValueTrue,
			api.KeyVisibility: api.ValueVisibilityPublic,
		},
		domain.NewContent(contentEmoji)},
	id.TOCNewTemplateZid: {

{{/HasUselessFiles}}
<dl>
{{#MetaPairs}}
<dt>{{Key}}:</dt><dd>{{Value}}</dd>
{{/MetaPairs}}
</dl>
<form method="POST">
<input class="zs-button" type="submit" value="Delete">
<input class="zs-primary" type="submit" value="Delete">
</form>
</article>
{{end}}

<article>
<header>
<h1>{{Heading}}</h1>
</header>
<form method="POST">
<div>
<label for="title">Title</label>
<input class="zs-input" type="text" id="title" name="title" placeholder="Title.." value="{{MetaTitle}}" autofocus>
<label for="zs-title">Title <a title="Main heading of this zettel. You can use inline zettelmarkup.">&#9432;</a></label>
<input class="zs-input" type="text" id="zs-title" name="title" placeholder="Title.." value="{{MetaTitle}}" autofocus>
</div>
<div>
<div>
<label for="role">Role</label>
<input class="zs-input" type="text" id="role" name="role" placeholder="role.." value="{{MetaRole}}">
<label for="zs-role">Role <a title="One word, without spaces, to set the main role of this zettel.">&#9432;</a></label>
<input class="zs-input" type="text" id="zs-role" {{#HasRoleData}}list="zs-role-data"{{/HasRoleData}} name="role" placeholder="role.." value="{{MetaRole}}">
{{#HasRoleData}}
<datalist id="zs-role-data">
{{#RoleData}}
<option value="{{.}}">
{{/RoleData}}
</datalist>
{{/HasRoleData}}
</div>
<label for="tags">Tags</label>
<input class="zs-input" type="text" id="tags" name="tags" placeholder="#tag" value="{{MetaTags}}">
<label for="zs-tags">Tags <a title="Tags must begin with an '#' sign. They are separated by spaces.">&#9432;</a></label>
<input class="zs-input" type="text" id="zs-tags" name="tags" placeholder="#tag" value="{{MetaTags}}">
</div>
<div>
<label for="meta">Metadata</label>
<textarea class="zs-input" id="meta" name="meta" rows="4" placeholder="metakey: metavalue">
<label for="zs-meta">Metadata <a title="Other metadata for this zettel. Each line contains a key/value pair, separated by a colon ':'.">&#9432;</a></label>
<textarea class="zs-input" id="zs-meta" name="meta" rows="4" placeholder="metakey: metavalue">
{{#MetaPairsRest}}
{{Key}}: {{Value}}
{{/MetaPairsRest}}
</textarea>
</div>
<div>
<label for="syntax">Syntax</label>
<input class="zs-input" type="text" id="syntax" name="syntax" placeholder="syntax.." value="{{MetaSyntax}}">
</div>
<label for="zs-syntax">Syntax <a title="Syntax of zettel content below, one word. Typically 'zmk' (for zettelmarkup).">&#9432;</a></label>
<input class="zs-input" type="text" id="zs-syntax" {{#HasSyntaxData}}list="zs-syntax-data"{{/HasSyntaxData}} name="syntax" placeholder="syntax.." value="{{MetaSyntax}}">
{{#HasSyntaxData}}
<datalist id="zs-syntax-data">
{{#SyntaxData}}
<option value="{{.}}">
{{/SyntaxData}}
</datalist>
{{/HasSyntaxData}}</div>
<div>
{{#IsTextContent}}
<label for="content">Content</label>
<textarea class="zs-input zs-content" id="meta" name="content" rows="20" placeholder="Your content..">{{Content}}</textarea>
<label for="zs-content">Content <a title="Content for this zettel, according to above syntax.">&#9432;</a></label>
<textarea class="zs-input zs-content" id="zs-content" name="content" rows="20" placeholder="Your content..">{{Content}}</textarea>
{{/IsTextContent}}
</div>
<div>
<input class="zs-button" type="submit" value="Submit">
<input class="zs-primary" type="submit" value="Submit">
<input class="zs-secondary" type="submit" value="Save" formaction="?save">
</div>
</form>
</article>

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

{{/HasUselessFiles}}
<form method="POST">
<div>
<label for="newid">New zettel id</label>
<input class="zs-input" type="text" id="newzid" name="newzid" placeholder="ZID.." value="{{Zid}}" autofocus>
</div>
<input type="hidden" id="curzid" name="curzid" value="{{Zid}}">
<input class="zs-button" type="submit" value="Rename">
<div><input class="zs-primary" type="submit" value="Rename"></div>
</form>
<dl>
{{#MetaPairs}}
<dt>{{Key}}:</dt><dd>{{Value}}</dd>
{{/MetaPairs}}
</dl>
</article>

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

	"zettelstore.de/c/api"
	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager"
	"zettelstore.de/z/box/notify"
	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/kernel"

	if !entry.IsValid() {
		return domain.Zettel{}, box.ErrNotFound
	}
	m, c, err := dp.srvGetMetaContent(ctx, entry, zid)
	if err != nil {
		return domain.Zettel{}, err
	}
	dp.cleanupMeta(m)
	zettel := domain.Zettel{Meta: m, Content: domain.NewContent(c)}
	dp.log.Trace().Zid(zid).Msg("GetZettel")
	return zettel, nil
}

func (dp *dirBox) GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
	m, err := dp.doGetMeta(ctx, zid)
	dp.log.Trace().Zid(zid).Err(err).Msg("GetMeta")
	return m, err
}
func (dp *dirBox) doGetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
	entry := dp.dirSrv.GetDirEntry(zid)
	if !entry.IsValid() {
		return nil, box.ErrNotFound
	}
	m, err := dp.srvGetMeta(ctx, entry, zid)
	if err != nil {
		return nil, err
	}
	dp.cleanupMeta(m)
	return m, nil
}

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

	// 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.cleanupMeta(m)
		dp.cdata.Enricher.Enrich(ctx, m, dp.number)
		handle(m)
	}
	return nil
}

func (dp *dirBox) CanUpdateZettel(context.Context, domain.Zettel) bool {

}

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")
}

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

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

package dirbox

//-----------------------------------------------------------------------------
// Copyright (c) 2021-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

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

	}
	return ext
}

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

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

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

//-----------------------------------------------------------------------------
// Copyright (c) 2021-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

package filebox

// Package manager coordinates the various boxes and indexes of a Zettelstore.
package manager

import (
	"context"
	"io"
	"net/url"
	"sort"
	"sync"
	"time"

	"zettelstore.de/c/maps"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager/memstore"
	"zettelstore.de/z/box/manager/store"
	"zettelstore.de/z/config"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"

	if _, ok := registry[scheme]; ok {
		panic(scheme)
	}
	registry[scheme] = create
}

// GetSchemes returns all registered scheme, ordered by scheme string.
func GetSchemes() []string {
func GetSchemes() []string { return maps.Keys(registry) }
	result := make([]string, 0, len(registry))
	for scheme := range registry {
		result = append(result, scheme)
	}
	sort.Strings(result)
	return result
}

// Manager is a coordinating box.
type Manager struct {
	mgrLog       *logger.Logger
	mgrMx        sync.RWMutex
	started      bool
	rtConfig     config.Config

	"fmt"
	"io"
	"sort"
	"strings"
	"sync"

	"zettelstore.de/c/api"
	"zettelstore.de/c/maps"
	"zettelstore.de/z/box/manager/store"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
)

type metaRefs struct {
	forward  id.Slice

}

func dumpStringRefs(w io.Writer, title, preString, postString string, srefs stringRefs) {
	if len(srefs) == 0 {
		return
	}
	fmt.Fprintln(w, "====", title)
	slice := make([]string, 0, len(srefs))
	for s := range srefs {
		slice = append(slice, s)
	}
	sort.Strings(slice)
	for _, s := range slice {
	for _, s := range maps.Keys(srefs) {
		fmt.Fprintf(w, "; %s%s%s\n", preString, s, postString)
		fmt.Fprintln(w, ":", srefs[s])
	}
}

import (
	"testing"

	"zettelstore.de/c/api"
	"zettelstore.de/z/domain/id"
	_ "zettelstore.de/z/parser/blob"       // Allow to use BLOB parser.
	_ "zettelstore.de/z/parser/draw"       // Allow to use draw parser.
	_ "zettelstore.de/z/parser/markdown"   // Allow to use markdown parser.
	_ "zettelstore.de/z/parser/none"       // Allow to use none parser.
	_ "zettelstore.de/z/parser/plain"      // Allow to use plain parser.
	_ "zettelstore.de/z/parser/zettelmark" // Allow to use zettelmark parser.
)

func TestSeekZid(t *testing.T) {

		}
	}
}

func TestNewExtIsBetter(t *testing.T) {
	extVals := []string{
		// Main Formats
		api.ValueSyntaxZmk, api.ValueSyntaxDraw, "markdown", "md",
		api.ValueSyntaxZmk, "markdown", "md",
		// Other supported text formats
		"css", "txt", api.ValueSyntaxHTML, api.ValueSyntaxNone, "mustache", api.ValueSyntaxText, "plain",
		// Supported graphics formats
		api.ValueSyntaxGif, "png", api.ValueSyntaxSVG, "jpeg", "jpg",
		// Unsupported syntax values
		"gz", "cpp", "tar", "cppc",
	}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

package notify

}

func calcContentExt(syntax string, yamlSep bool, getZettelFileSyntax func() []string) string {
	if yamlSep {
		return extZettel
	}
	switch syntax {
	case api.ValueSyntaxDraw, api.ValueSyntaxNone, api.ValueSyntaxZmk:
	case api.ValueSyntaxNone, api.ValueSyntaxZmk:
		return extZettel
	}
	for _, s := range getZettelFileSyntax() {
		if s == syntax {
			return extZettel
		}
	}

		domain.Zettel{
			Meta:    m,
			Content: domain.NewContent(inp.Src[inp.Pos:]),
		},
		m.GetDefault(api.KeySyntax, api.ValueSyntaxZmk),
		nil,
	)
	encdr := encoder.Create(api.Encoder(enc), &encoder.Environment{
	encdr := encoder.Create(api.Encoder(enc))
		Lang: m.GetDefault(api.KeyLang, api.ValueLangEN),
	})
	if encdr == nil {
		fmt.Fprintf(os.Stderr, "Unknown format %q\n", enc)
		return 2, nil
	}
	_, err = encdr.WriteZettel(os.Stdout, z, parser.ParseMetadata)
	if err != nil {
		return 2, err

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

// ---------- Subcommand: run ------------------------------------------------

func flgRun(fs *flag.FlagSet) {
	fs.String("c", defConfigfile, "configuration file")
	fs.String("c", "", "configuration file")
	fs.Uint("a", 0, "port number kernel service (0=disable)")
	fs.Uint("p", 23123, "port number web service")
	fs.String("d", "", "zettel directory")
	fs.Bool("r", false, "system-wide read-only mode")
	fs.Bool("v", false, "verbose mode")
	fs.Bool("debug", false, "debug mode")
}

	ucCreateZettel := usecase.NewCreateZettel(ucLog, rtConfig, protectedBoxManager)
	ucGetMeta := usecase.NewGetMeta(protectedBoxManager)
	ucGetAllMeta := usecase.NewGetAllMeta(protectedBoxManager)
	ucGetZettel := usecase.NewGetZettel(protectedBoxManager)
	ucParseZettel := usecase.NewParseZettel(rtConfig, ucGetZettel)
	ucEvaluate := usecase.NewEvaluate(rtConfig, ucGetZettel, ucGetMeta)
	ucListMeta := usecase.NewListMeta(protectedBoxManager)
	ucListSyntax := usecase.NewListSyntax(protectedBoxManager)
	ucListRoles := usecase.NewListRole(protectedBoxManager)
	ucListRoles := usecase.NewListRoles(protectedBoxManager)
	ucListTags := usecase.NewListTags(protectedBoxManager)
	ucZettelContext := usecase.NewZettelContext(protectedBoxManager, rtConfig)
	ucDelete := usecase.NewDeleteZettel(ucLog, protectedBoxManager)
	ucUpdate := usecase.NewUpdateZettel(ucLog, protectedBoxManager)
	ucRename := usecase.NewRenameZettel(ucLog, protectedBoxManager)
	ucUnlinkedRefs := usecase.NewUnlinkedReferences(protectedBoxManager, rtConfig)
	ucRefresh := usecase.NewRefresh(ucLog, protectedBoxManager)
	ucVersion := usecase.NewVersion(kernel.Main.GetConfig(kernel.CoreService, kernel.CoreVersion).(string))

	webSrv.Handle("/", wui.MakeGetRootHandler(protectedBoxManager))

	// Web user interface
	if !authManager.IsReadonly() {
		webSrv.AddZettelRoute('b', server.MethodGet, wui.MakeGetRenameZettelHandler(
			ucGetMeta, &ucEvaluate))
		webSrv.AddZettelRoute('b', server.MethodPost, wui.MakePostRenameZettelHandler(&ucRename))
		webSrv.AddZettelRoute('c', server.MethodGet, wui.MakeGetCreateZettelHandler(
			ucGetZettel, &ucCreateZettel))
			ucGetZettel, &ucCreateZettel, ucListRoles, ucListSyntax))
		webSrv.AddZettelRoute('c', server.MethodPost, wui.MakePostCreateZettelHandler(&ucCreateZettel))
		webSrv.AddZettelRoute('d', server.MethodGet, wui.MakeGetDeleteZettelHandler(
			ucGetMeta, ucGetAllMeta, &ucEvaluate))
		webSrv.AddZettelRoute('d', server.MethodPost, wui.MakePostDeleteZettelHandler(&ucDelete))
		webSrv.AddZettelRoute('e', server.MethodGet, wui.MakeEditGetZettelHandler(ucGetZettel))
		webSrv.AddZettelRoute('e', server.MethodGet, wui.MakeEditGetZettelHandler(ucGetZettel, ucListRoles, ucListSyntax))
		webSrv.AddZettelRoute('e', server.MethodPost, wui.MakeEditSetZettelHandler(&ucUpdate))
	}
	webSrv.AddListRoute('g', server.MethodGet, wui.MakeGetGoActionHandler(&ucRefresh))
	webSrv.AddListRoute('h', server.MethodGet, wui.MakeListHTMLMetaHandler(
		ucListMeta, ucListRoles, ucListTags, &ucEvaluate))
	webSrv.AddZettelRoute('h', server.MethodGet, wui.MakeGetHTMLZettelHandler(
		&ucEvaluate, ucGetMeta))
	webSrv.AddListRoute('i', server.MethodGet, wui.MakeGetLoginOutHandler())
	webSrv.AddListRoute('i', server.MethodPost, wui.MakePostLoginHandler(&ucAuthenticate))
	webSrv.AddZettelRoute('i', server.MethodGet, wui.MakeGetInfoHandler(
		ucParseZettel, &ucEvaluate, ucGetMeta, ucGetAllMeta, ucUnlinkedRefs))
	webSrv.AddZettelRoute('k', server.MethodGet, wui.MakeZettelContextHandler(
		ucZettelContext, &ucEvaluate))

	// API
	webSrv.AddListRoute('a', server.MethodPost, a.MakePostLoginHandler(&ucAuthenticate))
	webSrv.AddListRoute('a', server.MethodPut, a.MakeRenewAuthHandler())
	webSrv.AddListRoute('j', server.MethodGet, a.MakeListMetaHandler(ucListMeta))
	webSrv.AddZettelRoute('j', server.MethodGet, a.MakeGetZettelHandler(ucGetZettel))
	webSrv.AddListRoute('m', server.MethodGet, a.MakeListMapMetaHandler(ucListRoles, ucListTags))
	webSrv.AddZettelRoute('m', server.MethodGet, a.MakeGetMetaHandler(ucGetMeta))
	webSrv.AddZettelRoute('o', server.MethodGet, a.MakeGetOrderHandler(
		usecase.NewZettelOrder(protectedBoxManager, ucEvaluate)))
	webSrv.AddZettelRoute('p', server.MethodGet, a.MakeGetParsedZettelHandler(ucParseZettel))
	webSrv.AddListRoute('r', server.MethodGet, a.MakeListRoleHandler(ucListRoles))
	webSrv.AddListRoute('t', server.MethodGet, a.MakeListTagsHandler(ucListTags))
	webSrv.AddZettelRoute('u', server.MethodGet, a.MakeListUnlinkedMetaHandler(
		ucGetMeta, ucUnlinkedRefs, &ucEvaluate))
	webSrv.AddZettelRoute('v', server.MethodGet, a.MakeGetEvalZettelHandler(ucEvaluate))
	webSrv.AddListRoute('x', server.MethodGet, a.MakeGetDataHandler(ucVersion))
	webSrv.AddListRoute('x', server.MethodPost, a.MakePostCommandHandler(&ucIsAuth, &ucRefresh))
	webSrv.AddZettelRoute('x', server.MethodGet, a.MakeZettelContextHandler(ucZettelContext))
	webSrv.AddListRoute('z', server.MethodGet, a.MakeListPlainHandler(ucListMeta))

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

package cmd

import (
	"flag"
	"sort"

	"zettelstore.de/c/maps"
	"zettelstore.de/z/logger"
)

// Command stores information about commands / sub-commands.
type Command struct {
	Name       string              // command name as it appears on the command line
	Func       CommandFunc         // function that executes a command

// Get returns the command identified by the given name and a bool to signal success.
func Get(name string) (Command, bool) {
	cmd, ok := commands[name]
	return cmd, ok
}

// List returns a sorted list of all registered command names.
func List() []string {
func List() []string { return maps.Keys(commands) }
	result := make([]string, 0, len(commands))
	for name := range commands {
		result = append(result, name)
	}
	sort.Strings(result)
	return result
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

package cmd

import (
	"errors"
	"flag"
	"fmt"
	"net"
	"net/url"
	"os"
	"runtime/debug"
	"strconv"
	"strings"

	"zettelstore.de/c/api"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/auth/impl"
	"zettelstore.de/z/box"
	"zettelstore.de/z/box/compbox"
	"zettelstore.de/z/box/manager"
	"zettelstore.de/z/config"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/input"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/web/server"
)

const (
const strRunSimple = "run-simple"
	defConfigfile = ".zscfg"
)

func init() {
	RegisterCommand(Command{
		Name: "help",
		Func: func(*flag.FlagSet) (int, error) {
			fmt.Println("Available commands:")
			for _, name := range List() {

		Func:       runFunc,
		Boxes:      true,
		Header:     true,
		LineServer: true,
		SetFlags:   flgRun,
	})
	RegisterCommand(Command{
		Name:   "run-simple",
		Name:   strRunSimple,
		Func:   runFunc,
		Simple: true,
		Boxes:  true,
		Header: true,
		// LineServer: true,
		SetFlags: func(fs *flag.FlagSet) {
			// fs.Uint("a", 0, "port number kernel service (0=disable)")

	})
	RegisterCommand(Command{
		Name: "password",
		Func: cmdPassword,
	})
}

func readConfig(fs *flag.FlagSet) (cfg *meta.Meta) {
func fetchStartupConfiguration(fs *flag.FlagSet) (cfg *meta.Meta) {
	var configFile string
	if configFlag := fs.Lookup("c"); configFlag != nil {
		configFile = configFlag.Value.String()
	} else {
		configFile = defConfigfile
	}
	content, err := os.ReadFile(configFile)
		if filename := configFlag.Value.String(); filename != "" {
			content, err := readConfiguration(filename)
			return createConfiguration(content, err)
		}
	}
	content, err := searchAndReadConfiguration()
	return createConfiguration(content, err)
}

func createConfiguration(content []byte, err error) *meta.Meta {
	if err != nil {
		return meta.New(id.Invalid)
	}
	return meta.NewFromInput(id.Invalid, input.NewInput(content))
}

func readConfiguration(filename string) ([]byte, error) { return os.ReadFile(filename) }

func searchAndReadConfiguration() ([]byte, error) {
	for _, filename := range []string{"zettelstore.cfg", "zsconfig.txt", "zscfg.txt", "_zscfg"} {
		if content, err := readConfiguration(filename); err == nil {
			return content, nil
		}
	}
	return readConfiguration(".zscfg")
}

func getConfig(fs *flag.FlagSet) *meta.Meta {
	cfg := readConfig(fs)
	cfg := fetchStartupConfiguration(fs)
	fs.Visit(func(flg *flag.Flag) {
		switch flg.Name {
		case "p":
			if portStr, err := parsePort(flg.Value.String()); err == nil {
				cfg.Set(keyListenAddr, net.JoinHostPort("127.0.0.1", portStr))
			}
		case "a":

const (
	keyAdminPort         = "admin-port"
	keyDebug             = "debug-mode"
	keyDefaultDirBoxType = "default-dir-box-type"
	keyInsecureCookie    = "insecure-cookie"
	keyListenAddr        = "listen-addr"
	keyLogLevel          = "log-level"
	keyMaxRequestSize    = "max-request-size"
	keyOwner             = "owner"
	keyPersistentCookie  = "persistent-cookie"
	keyBoxOneURI         = kernel.BoxURIs + "1"
	keyReadOnly          = "read-only-mode"
	keyTokenLifetimeHTML = "token-lifetime-html"
	keyTokenLifetimeAPI  = "token-lifetime-api"
	keyURLPrefix         = "url-prefix"

	ok = setConfigValue(
		ok, kernel.WebService, kernel.WebListenAddress,
		cfg.GetDefault(keyListenAddr, "127.0.0.1:23123"))
	ok = setConfigValue(ok, kernel.WebService, kernel.WebURLPrefix, cfg.GetDefault(keyURLPrefix, "/"))
	ok = setConfigValue(ok, kernel.WebService, kernel.WebSecureCookie, !cfg.GetBool(keyInsecureCookie))
	ok = setConfigValue(ok, kernel.WebService, kernel.WebPersistentCookie, cfg.GetBool(keyPersistentCookie))
	if val, found := cfg.Get(keyMaxRequestSize); found {
		ok = setConfigValue(ok, kernel.WebService, kernel.WebMaxRequestSize, val)
	}
	ok = setConfigValue(
		ok, kernel.WebService, kernel.WebTokenLifetimeAPI, cfg.GetDefault(keyTokenLifetimeAPI, ""))
	ok = setConfigValue(
		ok, kernel.WebService, kernel.WebTokenLifetimeHTML, cfg.GetDefault(keyTokenLifetimeHTML, ""))

	if !ok {
		return errors.New("unable to set configuration")

		createManager = func(boxURIs []*url.URL, authManager auth.Manager, rtConfig config.Config) (box.Manager, error) {
			compbox.Setup(cfg)
			return manager.New(boxURIs, authManager, rtConfig)
		}
	} else {
		createManager = func([]*url.URL, auth.Manager, config.Config) (box.Manager, error) { return nil, nil }
	}

	secret := cfg.GetDefault("secret", "")
	if len(secret) < 16 && cfg.GetDefault(keyOwner, "") != "" {
		fmt.Fprintf(os.Stderr, "secret must have at least length 16 when authentication is enabled, but is %q\n", secret)
		return 2
	}

	kern.SetCreators(
		func(readonly bool, owner id.Zid) (auth.Manager, error) {
			return impl.New(readonly, owner, cfg.GetDefault("secret", "")), nil
			return impl.New(readonly, owner, secret), nil
		},
		createManager,
		func(srv server.Server, plMgr box.Manager, authMgr auth.Manager, rtConfig config.Config) error {
			setupRouting(srv, plMgr, authMgr, rtConfig)
			return nil
		},
	)

	kern.Shutdown(true)
	return exitCode
}

// runSimple is called, when the user just starts the software via a double click
// or via a simple call ``./zettelstore`` on the command line.
func runSimple() int {
	if _, err := searchAndReadConfiguration(); err == nil {
		return executeCommand(strRunSimple)
	}
	dir := "./zettel"
	if err := os.MkdirAll(dir, 0750); err != nil {
		fmt.Fprintf(os.Stderr, "Unable to create zettel directory %q (%s)\n", dir, err)
		return 1
	}
	return executeCommand("run-simple", "-d", dir)
	return executeCommand(strRunSimple, "-d", dir)
}

var cpuprofile = flag.String("cpuprofile", "", "write cpu profile to `file`")
var memprofile = flag.String("memprofile", "", "write memory profile to `file`")

// Main is the real entrypoint of the zettelstore.
func Main(progName, buildVersion string) int {
	fullVersion := retrieveFullVersion(buildVersion)
	kernel.Main.SetConfig(kernel.CoreService, kernel.CoreProgname, progName)
	kernel.Main.SetConfig(kernel.CoreService, kernel.CoreVersion, buildVersion)
	kernel.Main.SetConfig(kernel.CoreService, kernel.CoreVersion, fullVersion)
	flag.Parse()
	if *cpuprofile != "" || *memprofile != "" {
		if *cpuprofile != "" {
			kernel.Main.StartProfiling(kernel.ProfileCPU, *cpuprofile)
		} else {
			kernel.Main.StartProfiling(kernel.ProfileHead, *memprofile)
		}
		defer kernel.Main.StopProfiling()
	}
	args := flag.Args()
	if len(args) == 0 {
		return runSimple()
	}
	return executeCommand(args[0], args[1:]...)
}

func retrieveFullVersion(version string) string {
	info, ok := debug.ReadBuildInfo()
	if !ok {
		return version
	}
	var revision, dirty string
	for _, kv := range info.Settings {
		switch kv.Key {
		case "vcs.revision":
			revision = "+" + kv.Value
			if len(revision) > 11 {
				revision = revision[:11]
			}
		case "vcs.modified":
			if kv.Value == "true" {
				dirty = "-dirty"
			}
		}
	}
	return version + revision + dirty
}

import (
	_ "zettelstore.de/z/box/compbox"       // Allow to use computed box.
	_ "zettelstore.de/z/box/constbox"      // Allow to use global internal box.
	_ "zettelstore.de/z/box/dirbox"        // Allow to use directory box.
	_ "zettelstore.de/z/box/filebox"       // Allow to use file box.
	_ "zettelstore.de/z/box/membox"        // Allow to use in-memory box.
	_ "zettelstore.de/z/encoder/htmlenc"   // Allow to use HTML encoder.
	_ "zettelstore.de/z/encoder/nativeenc" // Allow to use native encoder.
	_ "zettelstore.de/z/encoder/sexprenc"  // Allow to use sexpr encoder.
	_ "zettelstore.de/z/encoder/textenc"   // Allow to use text encoder.
	_ "zettelstore.de/z/encoder/zjsonenc"  // Allow to use ZJSON encoder.
	_ "zettelstore.de/z/encoder/zmkenc"    // Allow to use zmk encoder.
	_ "zettelstore.de/z/kernel/impl"       // Allow kernel implementation to create itself
	_ "zettelstore.de/z/parser/blob"       // Allow to use BLOB parser.
	_ "zettelstore.de/z/parser/draw"       // Allow to use draw parser.
	_ "zettelstore.de/z/parser/markdown"   // Allow to use markdown parser.
	_ "zettelstore.de/z/parser/none"       // Allow to use none parser.
	_ "zettelstore.de/z/parser/plain"      // Allow to use plain parser.
	_ "zettelstore.de/z/parser/zettelmark" // Allow to use zettelmark parser.
)

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package config provides functions to retrieve runtime configuration data.

// Config allows to retrieve all defined configuration values that can be changed during runtime.
type Config interface {
	AuthConfig

	// AddDefaultValues enriches the given meta data with its default values.
	AddDefaultValues(m *meta.Meta) *meta.Meta

	// GetDefaultTitle returns the current value of the "default-title" key.
	GetDefaultTitle() string

	// GetDefaultRole returns the current value of the "default-role" key.
	GetDefaultRole() string

	// GetDefaultSyntax returns the current value of the "default-syntax" key.
	GetDefaultSyntax() string

	// GetDefaultLang returns the current value of the "default-lang" key.
	GetDefaultLang() string

	// GetSiteName returns the current value of the "site-name" key.
	GetSiteName() string

	// GetHomeZettel returns the value of the "home-zettel" key.
	GetHomeZettel() id.Zid

	// GetDefaultVisibility returns the default value for zettel visibility.
	GetDefaultVisibility() meta.Visibility

	// GetMaxTransclusions return the maximum number of indirect transclusions.
	GetMaxTransclusions() int

	// GetYAMLHeader returns the current value of the "yaml-header" key.
	GetYAMLHeader() bool

	// GetZettelFileSyntax returns the current value of the "zettel-file-syntax" key.

	// GetExpertMode returns the current value of the "expert-mode" key.
	GetExpertMode() bool

	// GetVisibility returns the visibility value of the metadata.
	GetVisibility(m *meta.Meta) meta.Visibility
}

// GetTitle returns the value of the "title" key of the given meta. If there
// is no such value, GetDefaultTitle is returned.
func GetTitle(m *meta.Meta, cfg Config) string {
	if val, ok := m.Get(api.KeyTitle); ok {
		return val
	}
	if cfg != nil {
		return cfg.GetDefaultTitle()
	}
	return "Untitled"
}

// GetRole returns the value of the "role" key of the given meta. If there
// is no such value, GetDefaultRole is returned.
func GetRole(m *meta.Meta, cfg Config) string {
	if val, ok := m.Get(api.KeyRole); ok {
		return val
	}
	return cfg.GetDefaultRole()
}

// GetSyntax returns the value of the "syntax" key of the given meta. If there
// is no such value, GetDefaultSyntax is returned.
func GetSyntax(m *meta.Meta, cfg Config) string {
	if val, ok := m.Get(api.KeySyntax); ok {
		return val
	}
	return cfg.GetDefaultSyntax()
}

// GetLang returns the value of the "lang" key of the given meta. If there is
// no such value, GetDefaultLang is returned.
func GetLang(m *meta.Meta, cfg Config) string {
	if val, ok := m.Get(api.KeyLang); ok {
		return val
	}
	return cfg.GetDefaultLang()
}

All you have to do is to open your web browser, enter the appropriate URL, and there you go.

On the negative side, you will not be notified when you enter the wrong data in the Task scheduler and Zettelstore fails to start.
This can be mitigated by first using the command line prompt to start Zettelstore with the appropriate options.
Once everything works, you can register Zettelstore to be automatically started by the task scheduler.
There you should make sure that you have followed the first steps as described on the [[parent page|00001003300000]].

To sart the Task scheduler management console, press the Windows logo key and the key ''R'', type ''taskschd.msc''.
To start the Task scheduler management console, press the Windows logo key and the key ''R'', type ''taskschd.msc''.
Select the OK button.

{{00001003305102}}

This will start the ""Task Scheduler"".

Now, create a new task with ""Create Task ...""

=== Launch Agent

If you want to execute Zettelstore automatically and less visible, and if you know a little bit about working in the terminal application, then you could try to run Zettelstore under the control of the [[Launchd system|https://developer.apple.com/library/archive/documentation/MacOSX/Conceptual/BPSystemStartup/Chapters/Introduction.html]].

First, you have to create a description for ""Launchd"".
This is a text file named ''zettelstore.plist'' with the following content.
It assumes that you have copied the Zettelstore executable in a local folder called ''~/bin'' and have created a file for [[startup configuration|00001004010000]] called ''zettelstore.cfg'', which is placed in the same folder[^If you are not using a confguration file, just remove the lines ``<string>-c</string>`` and ``<string>/Users/USERNAME/bin/zettelstore.cfg</string>``.]:
It assumes that you have copied the Zettelstore executable in a local folder called ''~/bin'' and have created a file for [[startup configuration|00001004010000]] called ''zettelstore.cfg'', which is placed in the same folder[^If you are not using a configuration file, just remove the lines ``<string>-c</string>`` and ``<string>/Users/USERNAME/bin/zettelstore.cfg</string>``.]:

```
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
	<dict>
		<key>Label</key>

id: 00001004010000
title: Zettelstore startup configuration
role: manual
tags: #configuration #manual #zettelstore
syntax: zmk
modified: 20220304115353
modified: 20220419193611

The configuration file, as specified by the ''-c CONFIGFILE'' [[command line option|00001004051000]], allows you to specify some startup options.
These options cannot be stored in a [[configuration zettel|00001004020000]] because either they are needed before Zettelstore can start or because of security reasons.
For example, Zettelstore need to know in advance, on which network address is must listen or where zettel are stored.
An attacker that is able to change the owner can do anything.
Therefore only the owner of the computer on which Zettelstore runs can change this information.

; [!log-level|''log-level'']
: Specify the global [[logging level|00001004059700]] for the whole application, overwriting the level ""debug"" set by configuration [[''debug-mode''|#debug-mode]].
  Can be changed at runtime, even for specific internal services, with the ''log-level'' command of the [[administrator console|00001004101000#log-level]].
  
  Default: ""info"".

  When you are familiar to operate the Zettelstore, you might set the level to ""warn"" or ""error"" to receive less noisy messages from the Zettelstore.
; [!max-request-size|''max-request-size'']
: Limits the maximum byte size of a web request body to prevent clients from accidentally or maliciously sending a large request and wasting server resources.
  The minimum value is 1024.

  Default: 16777216 (16 MiB). 
; [!owner|''owner'']
: [[Identifier|00001006050000]] of a zettel that contains data about the owner of the Zettelstore.
  The owner has full authorization for the Zettelstore.
  Only if owner is set to some value, user [[authentication|00001010000000]] is enabled.

  Ensure that key [[''secret''|#secret]] is set to a value of at least 16 bytes.
  Otherwise the Zettelstore will not start for security reasons.
; [!persistent-cookie|''persistent-cookie'']
: A [[boolean value|00001006030500]] to make the access cookie persistent.
  This is helpful if you access the Zettelstore via a mobile device.
  On these devices, the operating system is free to stop the web browser and to remove temporary cookies.
  Therefore, an authenticated user will be logged off.

  If ""true"", a persistent cookie is used.
  Its lifetime exceeds the lifetime of the authentication token (see option ''token-lifetime-html'') by 30 seconds.

  Default: ""false""
; [!read-only-mode|''read-only-mode'']
: Puts the Zettelstore service into a read-only mode, if set to a [[true value|00001006030500]].
  No changes are possible.

  Default: ""false"".
; [!secret|''secret'']
: A string value to make the communication with external clients strong enough so that sessions of the [[web user interface|00001014000000]] or [[API access token|00001010040700]] cannot be modified by some external unfriendly party.
  The string must have a length of at least 16 bytes.

  It is only needed to set this value, if [[authentication is enabled|00001010040100]] by setting key [[''owner''|#owner]] to some user identification.
; [!token-lifetime-api|''token-lifetime-api''], [!token-lifetime-html|''token-lifetime-html'']
: Define lifetime of access tokens in minutes.
  Values are only valid if authentication is enabled, i.e. key ''owner'' is set.

  ''token-lifetime-api'' is for accessing Zettelstore via its [[API|00001012000000]].
  Default: ""10"".

id: 00001004011400
title: Configure file directory boxes
role: manual
tags: #configuration #manual #zettelstore
syntax: zmk
modified: 20220307121244
modified: 20220724200512

Under certain circumstances, it is preferable to further configure a file directory box.
This is done by appending query parameters after the base box URI ''dir:\//DIR''.

The following parameters are supported:

|= Parameter:|Description|Default value:|
|type|(Sub-) Type of the directory service|(value of ""[[default-dir-box-type|00001004010000#default-dir-box-type]]"")
|worker|Number of worker that can access the directory in parallel|7
|readonly|Allow only operations that do not create or change zettel|n/a

=== Type
On some operating systems, Zettelstore tries to detect changes to zettel files outside of Zettelstore's control[^This includes Linux, Windows, and macOS.].
On other operating systems, this may be not possible, due to technical limitations.
Automatic detection of external changes is also not possible, if zettel files are put on an external service, such as a file server accessed via SMD/CIFS or NFS.
Automatic detection of external changes is also not possible, if zettel files are put on an external service, such as a file server accessed via SMB/CIFS or NFS.

To cope with this uncertainty, Zettelstore provides various internal implementations of a directory box.
The default values should match the needs of different users, as explained in the [[installation part|00001003000000]] of this manual.
The following values are supported:

; simple
: Is not able to detect external changes.

id: 00001004020000
title: Configure the running Zettelstore
role: manual
tags: #configuration #manual #zettelstore
syntax: zmk
modified: 20220304114412
modified: 20220628110920

You can configure a running Zettelstore by modifying the special zettel with the ID [[00000000000100]].
This zettel is called __configuration zettel__.
The following metadata keys change the appearance / behavior of Zettelstore:

; [!default-copyright|''default-copyright'']
: Copyright value to be used when rendering content.

  This value is also used to specify the language for all non-zettel content, e.g. lists or search results.

  Use values according to the language definition of [[RFC-5646|https://tools.ietf.org/html/rfc5646]].
; [!default-license|''default-license'']
: License value to be used when rendering content.
  Can be overwritten in a zettel with [[meta key|00001006020000]] ''license''.
  Default: (the empty string).
; [!default-role|''default-role'']
: Role to be used, if a zettel specifies no ''role'' [[meta key|00001006020000]].
  Default: ""zettel"".
; [!default-syntax|''default-syntax'']
: Syntax to be used, if a zettel specifies no ''syntax'' [[meta key|00001006020000]].
  Default: ""zmk"" (""[[Zettelmarkup|00001007000000]]"").
; [!default-title|''default-title'']
: Title to be used, if a zettel specifies no ''title'' [[meta key|00001006020000]].
  Default: ""Untitled"".

  You can use all [[inline-structured elements|00001007040000]] of Zettelmarkup.
; [!default-visibility|''default-visibility'']
: Visibility to be used, if zettel does not specify a value for the [[''visibility''|00001006020000#visibility]] metadata key.
  Default: ""login"".
; [!expert-mode|''expert-mode'']
: If set to a [[boolean true value|00001006030500]], all zettel with [[visibility ""expert""|00001010070200]] will be shown (to the owner, if [[authentication is enabled|00001010040100]]; to all, otherwise).
  This affects most computed zettel.
  Default: ""False"".

id: 00001004051000
title: The ''run'' sub-command
role: manual
tags: #command #configuration #manual #zettelstore
syntax: zmk
modified: 20220214175947
modified: 20220724162050

=== ``zettelstore run``
This starts the web service.

```
zettelstore run [-a PORT] [-c CONFIGFILE] [-d DIR] [-debug] [-p PORT] [-r] [-v]
```

; [!a|''-a PORT'']
: Specifies the TCP port through which you can reach the [[administrator console|00001004100000]].
  See the explanation of [[''admin-port''|00001004010000#admin-port]] for more details.
; [!c|''-c CONFIGFILE'']
: Specifies ''CONFIGFILE'' as a file, where [[startup configuration data|00001004010000]] is read.
  It is ignored, when the given file is not available, nor readable.

  Default: ''./.zscfg''. (''.\\.zscfg'' on Windows)), where ''.'' denotes the ""current directory"".
  Default: tries to read the following files in the ""current directory"": ''zettelstore.cfg'', ''zsconfig.txt'', ''zscfg.txt'', ''_zscfg'', and ''.zscfg''. 
; [!d|''-d DIR'']
: Specifies ''DIR'' as the directory that contains all zettel.

  Default is ''./zettel'' (''.\\zettel'' on Windows), where ''.'' denotes the ""current directory"".
; [!debug|''-debug'']
: Allows better debugging of the internal web server by disabling any timeout values.
  You should specify this only as a developer.

id: 00001004051100
title: The ''run-simple'' sub-command
role: manual
tags: #command #configuration #manual #zettelstore
syntax: zmk
modified: 20220214180253
modified: 20220724162843

=== ``zettelstore run-simple``
This sub-command is implicitly called, when an user starts Zettelstore by double-clicking on its GUI icon.
It is s simplified variant of the [[''run'' sub-command|00001004051000]].

First, this sub-command checks if it can read a [[Zettelstore startup configuration|00001004010000]] file by trying the [[default values|00001004051000#c]].
If this is the case, ''run-simple'' just continues as the [[''run'' sub-command|00001004051000]], but ignores any command line options (including ''-d DIR'').[^This allows a [[curious user|00001003000000]] to become an intermediate user.]


It allows only to specify a zettel directory.
If no startup configuration was found, the sub-command allows only to specify a zettel directory.
The directory will be created automatically, if it does not exist.
This is a difference to the ''run'' sub-command, where the directory must exists.
In contrast to the ''run'' sub-command, other command line parameter are not allowed.

```
zettelstore run-simple [-d DIR]
```

; [!d|''-d DIR'']
: Specifies ''DIR'' as the directory that contains all zettel.

  Default is ''./zettel'' (''.\\zettel'' on Windows), where ''.'' denotes the ""current directory"".

id: 00001004051200
title: The ''file'' sub-command
role: manual
tags: #command #configuration #manual #zettelstore
syntax: zmk
modified: 20220209114650
modified: 20220423131738

Reads zettel data from a file (or from standard input / stdin) and renders it to standard output / stdout.
This allows Zettelstore to render files manually.
```
zettelstore file [-t FORMAT] [file-1 [file-2]]
```

; ''-t FORMAT''
: Specifies the output format.
  Supported values are:
  [[''html''|00001012920510]] (default),
  [[''native''|00001012920513]],
  [[''sexpr''|00001012920516]],
  [[''text''|00001012920519]],
  [[''zjson''|00001012920503]],
  and [[''zmk''|00001012920522]].
; ''file-1''
: Specifies the file name, where at least metadata is read.
  If ''file-2'' is not given, the zettel content is also read from here.
; ''file-2''
: File name where the zettel content is stored.

If neither ''file-1'' nor ''file-2'' are given, metadata and zettel content are read from standard input / stdin.

In fact, the administrator console is __not__ a full telnet service.
It is merely a simple line-oriented service where each input line is interpreted separately.
Therefore, you can also use tools like [[netcat|https://nc110.sourceforge.io/]], [[socat|http://www.dest-unreach.org/socat/]], etc.

After connecting to the administrator console, there is no further authentication.
It is not needed because you must be logged in on the same computer where Zettelstore is running.
You cannot connect to the administrator console if you are on a different computer.
Of course, on multi-user systems with untrusted users, you should not enable the administrator console.
Of course, on multi-user systems with encrusted users, you should not enable the administrator console.

* Enable via [[command line|00001004051000#a]]
* Enable via [[configuration file|00001004010000#admin-port]]
* [[List of supported commands|00001004101000]]

# the empty file extension is used, when the content must be stored in its own file, e.g. image data;
  in this case, the filename just the 14 digits of the zettel identifier, and optional characters except the period ''"."''.  
Other filename extensions are used to determine the ""syntax"" of a zettel.
This allows to use other content within the Zettelstore, e.g. images or HTML templates.

For example, you want to store an important figure in the Zettelstore that is encoded as a ''.png'' file.
Since each zettel contains some metadata, e.g. the title of the figure, the question arises where these data should be stores.
The solution is a metafile with the same zettel identifier, but without a filename extension.
The solution is a meta-file with the same zettel identifier, but without a filename extension.
Zettelstore recognizes this situation and reads in both files for the one zettel containing the figure.
It maintains this relationship as long as theses files exists.

In case of some textual zettel content you do not want to store the metadata and the zettel content in two different files.
Here the ''.zettel'' extension will signal that the metadata and the zettel content will be put in the same file, separated by an empty line or a line with three dashes (""''-\-\-''"", also known as ""YAML separator"").

=== Predefined zettel

Zettelstore contains some [[predefined zettel|00001005090000]] to work properly.
The [[configuration zettel|00001004020000]] is one example.
To render the builtin [[web user interface|00001014000000]], some templates are used, as well as a [[layout specification in CSS|00000000020001]].
The icon that visualizes a broken image is a [[predefined GIF image|00000000040001]].
All of these are visible to the Zettelstore as zettel.

One reason for this is to allow you to modify these zettel to adapt Zettelstore to your needs and visual preferences.

Where are these zettel stored?
They are stored within the Zettelstore software itself, because one [[design goal|00001002000000]] was to have just one executable file to use Zettelstore.
But data stored within an executable programm cannot be changed later[^Well, it can, but it is a very bad idea to allow this. Mostly for security reasons.].
But data stored within an executable program cannot be changed later[^Well, it can, but it is a very bad idea to allow this. Mostly for security reasons.].

To allow changing predefined zettel, both the file store and the internal zettel store are internally chained together.
If you change a zettel, it will be always stored as a file.
If a zettel is requested, Zettelstore will first try to read that zettel from a file.
If such a file was not found, the internal zettel store is searched secondly.

Therefore, the file store ""shadows"" the internal zettel store.

id: 00001005090000
title: List of predefined zettel
role: manual
tags: #manual #reference #zettelstore
syntax: zmk
modified: 20211229000646
modified: 20220321192401

The following table lists all predefined zettel with their purpose.

|= Identifier :|= Title | Purpose
| [[00000000000001]] | Zettelstore Version | Contains the version string of the running Zettelstore
| [[00000000000002]] | Zettelstore Host | Contains the name of the computer running the Zettelstore
| [[00000000000003]] | Zettelstore Operating System | Contains the operating system and CPU architecture of the computer running the Zettelstore
| [[00000000000004]] | Zettelstore License | Lists the license of Zettelstore
| [[00000000000005]] | Zettelstore Contributors | Lists all contributors of Zettelstore
| [[00000000000006]] | Zettelstore Dependencies | Lists all licensed content
| [[00000000000007]] | Zettelstore Log | Lists the last 8192 log messages
| [[00000000000020]] | Zettelstore Box Manager | Contains some statistics about zettel boxes and the the index process
| [[00000000000090]] | Zettelstore Supported Metadata Keys | Contains all supported metadata keys, their [[types|00001006030000]], and more
| [[00000000000092]] | Zettelstore Supported Parser | Lists all supported values for metadata [[syntax|00001006020000#syntax]] that are recognized by Zettelstore
| [[00000000000096]] | Zettelstore Startup Configuration | Contains the effective values of the [[startup configuration|00001004010000]]
| [[00000000000100]] | Zettelstore Runtime Configuration | Allows to [[configure Zettelstore at runtime|00001004020000]]
| [[00000000010100]] | Zettelstore Base HTML Template | Contains the general layout of the HTML view
| [[00000000010200]] | Zettelstore Login Form HTML Template | Layout of the login form, when authentication is [[enabled|00001010040100]]
| [[00000000010300]] | Zettelstore List Meta HTML Template | Used when displaying a list of zettel
| [[00000000010401]] | Zettelstore Detail HTML Template | Layout for the HTML detail view of one zettel
| [[00000000010402]] | Zettelstore Info HTML Templöate | Layout for the information view of a specific zettel
| [[00000000010402]] | Zettelstore Info HTML Template | Layout for the information view of a specific zettel
| [[00000000010403]] | Zettelstore Form HTML Template | Form that is used to create a new or to change an existing zettel that contains text
| [[00000000010404]] | Zettelstore Rename Form HTML Template | View that is displayed to change the [[zettel identifier|00001006050000]]
| [[00000000010405]] | Zettelstore Delete HTML Template | View to confirm the deletion of a zettel
| [[00000000010500]] | Zettelstore List Roles HTML Template | Layout for listing all roles
| [[00000000010600]] | Zettelstore List Tags HTML Template | Layout of tags lists
| [[00000000020001]] | Zettelstore Base CSS | System-defined CSS file that is included by the [[Base HTML Template|00000000010100]]
| [[00000000025001]] | Zettelstore User CSS | User-defined CSS file that is included by the [[Base HTML Template|00000000010100]]
| [[00000000029000]] | Zettelstore Role to CSS Map | Maps [[role|00001006020000#role]] to a zettel identifier that is included by the [[Base HTML Template|00000000010100]] as an CSS file 
| [[00000000040001]] | Generic Emoji | Image that is shown if [[original image reference|00001007040322]] is invalid
| [[00000000090000]] | New Menu | Contains items that should contain in the zettel template menu
| [[00000000090001]] | New Zettel | Template for a new zettel with role ""[[zettel|00001006020100]]""
| [[00000000090002]] | New User | Template for a new [[user zettel|00001010040200]]
| [[00010000000000]] | Home | Default home zettel, contains some welcome information

If a zettel is not linked, it is not accessible for the current user.

**Important:** All identifier may change until a stable version of the software is released.

id: 00001006000000
title: Layout of a Zettel
role: manual
tags: #design #manual #zettelstore
syntax: zmk
modified: 20220113185522
modified: 20220724165931

A zettel consists of two parts: the metadata and the zettel content.
Metadata gives some information mostly about the zettel content, how it should be interpreted, how it is sorted within Zettelstore.
The zettel content is, well, the actual content.
In many cases, the content is in plain text form.
Plain text is long-lasting.
However, content in binary format is also possible.

The zettel content is your valuable content.
Zettelstore contains some predefined parsers that interpret the zettel content to the syntax of the zettel.
This includes markup languages, like [[Zettelmarkup|00001007000000]] and [[CommonMark|00001008010500]].
Other text formats are also supported, like CSS and HTML templates.
Plain text content is always Unicode, encoded as UTF-8.
Other character encodings are not supported and will never be[^This is not a real problem, since every modern software should support UTF-8 as an encoding.].
There is support for a graphical format with a text represenation: SVG.
There is support for a graphical format with a text representation: SVG.
And there is support for some binary image formats, like GIF, PNG, and JPEG.

=== Plain, parsed, and evaluated zettel
Zettelstore may present your zettel in various forms.
One way is to present the zettel as it was read by Zettelstore.
This is called ""[[plain zettel|00001003000000#plain]]"", typically retrieved with the [[endpoint|00001012920000]] ''/z/{ID}''.

The second way is to present the zettel as it was recognized by Zettelstore.
This is called ""[[parsed zettel|00001012053600]]"", typically retrieved with the [[endpoint|00001012920000]] ''/p/{ID}''.
Such a zettel was read and analyzed.
It can be presented in various [[encodings|00001012920500]].[^The [[zmk encoding|00001012920522]] allows you to compare the plain, the parsed, and the evaluated form of a zettel.]

However, a zettel such as this one you are currently reading, is a ""[[evaluated zettel|00001012053500]]"", typically retrieved with the [[endpoint|00001012920000]] ''/v/{ID}''.
The biggest difference to a parsed zettel is the inclusion of [[block transclusions|00001007031100]] or [[inline transclusions|00001007040324]] for an evaluated zettel.
It can also be presented in various encoding, including the ""zmk"" encoding.
Evaluations also applies to metadata of a zettel, if appropriate.

Please note, that searching for content is based on parsed zettel.
Transcluded content will only be found in transcluded zettel, but not in the zettel that transcluded the content.
However, you will easily pick up that zettel by follow the [[backward|00001006020000#backward]] metadata key of the transcluded zettel.

id: 00001006020000
title: Supported Metadata Keys
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
modified: 20220218130146
modified: 20220628111132

Although you are free to define your own metadata, by using any key (according to the [[syntax|00001006010000]]), some keys have a special meaning that is enforced by Zettelstore.
See the [[computed list of supported metadata keys|00000000000090]] for details.

Most keys conform to a [[type|00001006030000]].

; [!all-tags|''all-tags'']
: A property (a computed values that is not stored) that contains both the value of [[''tags''|#tags]] together with all [[tags|00001007040000#tag]] that are specified within the content.
; [!back|''back'']
: Is a property that contains the identifier of all zettel that reference the zettel of this metadata, that are not referenced by this zettel.
  Basically, it is the value of [[''backward''|#bachward]], but without any zettel identifier that is contained in [[''forward''|#forward]].
  Basically, it is the value of [[''backward''|#backward]], but without any zettel identifier that is contained in [[''forward''|#forward]].
; [!backward|''backward'']
: Is a property that contains the identifier of all zettel that reference the zettel of this metadata.
  References within invertible values are not included here, e.g. [[''precursor''|#precursor]].
; [!box-number|''box-number'']
: Is a computed value and contains the number of the box where the zettel was found.
  For all but the [[predefined zettel|00001005090000]], this number is equal to the number __X__ specified in startup configuration key [[''box-uri-__X__''|00001004010000#box-uri-x]].
; [!copyright|''copyright'']

; [!read-only|''read-only'']
: Marks a zettel as read-only.
  The interpretation of [[supported values|00001006020400]] for this key depends, whether authentication is [[enabled|00001010040100]] or not.
; [!role|''role'']
: Defines the role of the zettel.
  Can be used for selecting zettel.
  See [[supported zettel roles|00001006020100]].
  If not given, the value ''default-role'' from the [[configuration zettel|00001004020000#default-role]] will be used.
  If not given, it is ignored.
; [!syntax|''syntax'']
: Specifies the syntax that should be used for interpreting the zettel.
  The zettel about [[other markup languages|00001008000000]] defines supported values.
  If not given, the value ''default-syntax'' from the [[configuration zettel|00001004020000#default-syntax]] will be used.
  If it is not given, it defaults to ''plain''.
; [!tags|''tags'']
: Contains a space separated list of tags to describe the zettel further.
  Each Tag must begin with the number sign character (""''#''"", U+0023).
; [!title|''title'']
: Specifies the title of the zettel.
  If not given, the value ''default-title'' from the [[configuration zettel|00001004020000#default-title]] will be used.
  If not given, the value of [[''id''|#id]] will be used.

  You can use all [[inline-structured elements|00001007040000]] of Zettelmarkup.
; [!url|''url'']
: Defines an URL / URI for this zettel that possibly references external material.
  One use case is to specify the document that the current zettel comments on.
  The URL will be rendered special in the [[web user interface|00001014000000]] if you use the default template.
; [!useless-files|''useless-files'']

id: 00001006020100
title: Supported Zettel Roles
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
modified: 20220214174553
modified: 20220623183234

The [[''role'' key|00001006020000#role]] defines what kind of zettel you are writing.
You are free to define your own roles.

It is allowed to set an empty value or to omit the role.
The role ''zettel'' is predefined as the default role, but you can [[change this|00001004020000#default-role]].

Some roles are defined for technical reasons:

; [!configuration|''configuration'']
: A zettel that contains some configuration data for the Zettelstore.
  Most prominent is [[00000000000100]], as described in [[00001004020000]].
; [!manual|''manual'']

id: 00001006036000
title: WordSet Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
modified: 20220111103714
modified: 20220724201056

Values of this type denote a (sorted) set of [[words|00001006035500]].

A set is different to a list, as no duplicate values are allowed.

=== Allowed values
Must be a sequence of at least one word, separated by space characters.

=== Match operator
A value matches an wordset value, if the first value is equal to one of the word values in the word set.
A value matches a WordSet value, if the first value is equal to one of the word values in the word set.

=== Sorting
Sorting is done by comparing the [[String|00001006033500]] values.

id: 00001006055000
title: Reserved zettel identifier
role: manual
tags: #design #manual #zettelstore
syntax: zmk
modified: 20211124182600
modified: 20220311111751

[[Zettel identifier|00001006050000]] are typically created by examine the current date and time.
By renaming a zettel, you are able to provide any sequence of 14 digits.
If no other zettel has the same identifier, you are allowed to rename a zettel.

To make things easier, you normally should not use zettel identifier that begin with four zeroes (''0000'').

| 00009000000000 | 0000999999999 | Reserved for applications

This list may change in the future.

==== External Applications
|= From | To | Description
| 00009000001000 | 00009000001999 | [[Zettel Presenter|https://zettelstore.de/contrib]], an application to display zettel as a HTML-based slideshow
| 00009000002000 | 00009000002999 | [[Zettel Blog|https://zettelstore.de/contrib]], an application to collect and transform zettel into a blog

id: 00001007000000
title: Zettelmarkup
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20220113185501

Zettelmarkup is a rich plain-text based markup language for writing zettel content.
Besides the zettel content, Zettelmarkup is also used for specifying the title of a zettel, regardless of the syntax of a zettel.

Zettelmark supports the longevity of stored notes by providing a syntax that any person can easily read, as well as a computer.
Zettelmark can be much easier parsed / consumed by a software compared to other markup languages.
Zettelmarkup supports the longevity of stored notes by providing a syntax that any person can easily read, as well as a computer.
Zettelmarkup can be much easier parsed / consumed by a software compared to other markup languages.
Writing a parser for [[Markdown|https://daringfireball.net/projects/markdown/syntax]] is quite challenging.
[[CommonMark|00001008010500]] is an attempt to make it simpler by providing a comprehensive specification, combined with an extra chapter to give hints for the implementation.
Zettelmark follows some simple principles that anybody who knows to ho write software should be able understand to create an implementation.
Zettelmarkup follows some simple principles that anybody who knows to ho write software should be able understand to create an implementation.

Zettelmarkup is a markup language on its own.
This is in contrast to Markdown, which is basically a superset of HTML.
This is in contrast to Markdown, which is basically a super-set of HTML.
While HTML is a markup language that will probably last for a long time, it cannot be easily translated to other formats, such as PDF, JSON, or LaTeX.
Additionally, it is allowed to embed other languages into HTML, such as CSS or even JavaScript.
This could create problems with longevity as well as security problems.

Zettelmarkup is a rich markup language, but it focusses on relatively short zettel content.
Zettelmarkup is a rich markup language, but it focuses on relatively short zettel content.
It allows embedding other content, simple tables, quotations, description lists, and images.
It provides a broad range of inline formatting, including __emphasized__, **strong**, ~~deleted~~{-} and >>inserted>> text.
Footnotes[^like this] are supported, links to other zettel and to external material, as well as citation keys.

Zettelmarkup might be seen as a proprietary markup language.
But if you want to use [[Markdown/CommonMark|00001008010000]] and you need support for footnotes or tables, you'll end up with proprietary extensions.
However, the Zettelstore supports CommonMark as a zettel syntax, so you can mix both Zettelmarkup zettel and CommonMark zettel in one store to get the best of both worlds.

Some inline elements do not follow the rule of two identical character, especially to specify [[footnotes|00001007040330]], [[citation keys|00001007040340]], and local marks.
These elements begin with one opening square bracket (""``[``""), use a character for specifying the kind of the inline, typically allow to specify some content, and end with one closing square bracket (""``]``"").

One inline element that does not begin with two characters is the ""entity"".
It allows to specify any Unicode character.
The specification of that character is put between an ampersand character and a semicolon: ``&...;``{=zmk}.
For exmple, an ""n-dash"" could also be specified as ``–``{==zmk}.
For example, an ""n-dash"" could also be specified as ``–``{==zmk}.

The backslash character (""``\\``"") possibly gives the next character a special meaning.
This allows to resolve some left ambiguities.
For example, a list of depth 2 will begin a line with ``** Item 2.2``{=zmk}.
An inline element to strongly emphasize some text begin with a space will be specified as ``** Text**``{=zmk}.
To force the inline element formatting at the beginning of a line, ``**\\ Text**``{=zmk} should better be specified.

id: 00001007030000
title: Zettelmarkup: Block-Structured Elements
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20220201133655
modified: 20220311181036

Every markup for blocks-structured elements (""blocks"") begins at the very first position of a line.

There are five kinds of blocks: lists, one-line blocks, line-range blocks, tables, and paragraphs.

=== Lists

Additionally, all other blocks elements are allowed in line-range blocks.

* [[Verbatim blocks|00001007030500]] do not interpret their content,
* [[Quotation blocks|00001007030600]] specify a block-length quotations,
* [[Verse blocks|00001007030700]] allow to enter poetry, lyrics and similar text, where line endings are important,
* [[Region blocks|00001007030800]] just mark regions, e.g. for common formatting,
* [[Comment blocks|00001007030900]] allow to enter text that will be ignored when rendered.
* [[Evaluation blocks|00001007031300]] specify some content to be evaluated by either Zettelstore or external software.
* [[Math-mode blocks|00001007031400]] can be used to enter mathematical formulas / equations.
* [[Inline-Zettel blocks|00001007031200]] provide a mechanism to specify zettel content with a new syntax without creating a new zettel.

=== Tables

Similar to lists are tables not specified explicitly.
A sequence of table rows is considered a [[table|00001007031000]].
A table row itself is a sequence of table cells.

*# A.3
* B

* C
:::

Please note that two lists cannot be separated by an empty line.
Instead you should put a horizonal rule (""thematic break"") between them.
Instead you should put a horizontal rule (""thematic break"") between them.
You could also use a [[mark element|00001007040350]] or a hard line break to separate the two lists:
```zmk
# One
# Two
[!sep]
# Uno
# Due

id: 00001007030600
title: Zettelmarkup: Quotation Blocks
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20220218131806

A simple way to enter a quotation is to use the [[quotation list|00001007030200]].
A quotation list loosely follows the convention of quoting text within emails.
However, if you want to attribute the quotation to seomeone, a quotation block is more appropriately.
However, if you want to attribute the quotation to someone, a quotation block is more appropriately.

This kind of line-range block begins with at least three less-than characters (""''<''"", U+003C) at the first position of a line.
You can add some [[attributes|00001007050000]] on the beginning line of a quotation block, following the initiating characters.
The quotation does not support the default attribute, nor the generic attribute.
Attributes are interpreted on HTML rendering.
Any other character in this line will be ignored

id: 00001007030800
title: Zettelmarkup: Region Blocks
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20220218131131
modified: 20220323190829

Region blocks does not directly have a visual representation.
They just group a range of lines.
You can use region blocks to enter [[attributes|00001007050000]] that apply only to this range of lines.
One example is to enter a multi-line warning that should be visible.

This kind of line-range block begins with at least three colon characters (""'':''"", U+003A) at the first position of a line[^Since a [[description text|00001007030100]] only use exactly one colon character at the first position of a line, there is no possible ambiguity between these elements.].
You can add some [[attributes|00001007050000]] on the beginning line of a region block, following the initiating characters.
The region block does not support the default attribute, but it supports the generic attribute.
Some generic attributes, like ``=note``, ``=warning`` will be rendered special.
All other generic attributes are used as a CSS class definition.
Attributes are interpreted on HTML rendering.
Any other character in this line will be ignored.

Text following the beginning line will be interpreted, until a line begins with at least the same number of the same characters given at the beginning line.
This allows to enter a region block within a region block.
At the ending line, you can enter some [[inline elements|00001007040000]] after the colon characters.
These will interpreted as some attribution text.

Generic attributes that are result in a special HTML rendering are:
* example
* note
* tip
* important
* caution
* warning

All other generic attribute values are rendered as a CSS class:
```zmk
:::abc
def
:::
```
is rendered as
::::example
:::abc
def
:::
::::

While the text entered inside a verbatim block will be processed somehow, text inside a comment block will be ignored[^Well, not completely ignored: text is read, but it will typically not rendered visible.].
Comment blocks are typically used to give some internal comments, e.g. the license of a text or some internal remarks.

Comment blocks begin with at least three percent sign characters (""''%''"", U+0025) at the first position of a line.
You can add some [[attributes|00001007050000]] on the beginning line of a comment block, following the initiating characters.
The comment block supports the default attribute: when given, the text will be rendered, e.g. as an HTML comment.
When rendered to JSON, the comment block will not be ignored but it will output some JSON text.
Same for other renderers.
Same for other renderer.

Any other character in this line will be ignored

Text following the beginning line will not be interpreted, until a line begins with at least the same number of the same characters given at the beginning line.
This allows to enter some percent sign characters in the text that should not be interpreted.

For example:

id: 00001007031000
title: Zettelmarkup: Tables
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20220218131107

Tables are used to show some data in a two-dimenensional fashion.
Tables are used to show some data in a two-dimensional fashion.
In zettelmarkup, table are not specified explicitly, but by entering __table rows__.
Therefore, a table can be seen as a sequence of table rows.
A table row is nothing as a sequence of __table cells__.
The length of a table is the number of table rows, the width of a table is the maximum length of its rows.

The first cell of a row must begin with the vertical bar character (""''|''"", U+007C) at the first position of a line.
The other cells of a row begin with the same vertical bar character at later positions in that line.

id: 00001007031200
title: Zettelmarkup: Inline-Zettel Block
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20220218172121
modified: 20220311112247

An inline-zettel block allows to specify some content with another syntax without creating a new zettel.
This is useful, for example, if you want to specify a [[simple drawing|00001008050000]] within your zettel and you are sure that you do not need the drawing in another context.
Another example is to embed some [[Markdown|00001008010500]] content, because you are too lazy to translate Markdown into Zettelmarkup.[^However, translating into Zettelmarkup is quite easy with the [[zmk encoder|00001012920522]].]
A last example is to specify HTML code to use it for some kind of web frontend framework.
This is useful, for example, if you want to embed some [[Markdown|00001008010500]] content, because you are too lazy to translate Markdown into Zettelmarkup.
Another example is to specify HTML code to use it for some kind of web front-end framework.

As all other [[line-range blocks|00001007030000#line-range-blocks]], an inline-zettel block begins with at least three identical characters, starting at the first position of a line.
For inline-zettel blocks, the at-sign character (""''@''"", U+0040) is used.

You can add some [[attributes|00001007050000]] on the beginning line of a verbatim block, following the initiating characters.
The inline-zettel block uses the attribute key ""syntax"" to specify the [[syntax|00001008000000]] of the inline-zettel.
Alternatively, you can use the generic attribute to specify the syntax value.
If no value is provided, ""draw"" is assumed.
If no value is provided, ""[[text|00001008000000#text]]"" is assumed.

Any other character in this first line will be ignored.

Text following the beginning line will not be interpreted, until a line begins with at least the same number of the same at-sign characters given at the beginning line.
This allows to enter some at-sign characters in the text that should not be interpreted at this level.

Some examples:
```zmk
@@@draw
+-------+      +-------+
| Box 1 | ---> | Box 2 |
+-------+      +-------+
@@@
```
This will be rendered as:
:::example
@@@draw
+-------+      +-------+
| Box 1 | ---> | Box 2 |
+-------+      +-------+
@@@
:::

Using Markdown syntax:
```zmk
@@@markdown
A link to [this](00001007031200) zettel.
@@@
```
will be rendered as:
:::example
@@@markdown

id: 00001007031300
title: Zettelmarkup: Evaluation Blocks
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20220311120658

Evaluation blocks are used to enter text that could be evaluated by either Zettelstore or external software.
They begin with at least three tilde characters (""''~''"", U+007E) at the first position of a line.

You can add some [[attributes|00001007050000]] on the beginning line of a verbatim block, following the initiating characters.
The evaluation block supports the default attribute[^Depending on the syntax value.]: when given, all spaces in the text are rendered in HTML as open box characters (U+2423).
If you want to give only one attribute and this attribute is the generic attribute, you can omit the most of the attribute syntax and just specify the value.
It will be interpreted as a [[syntax|00001008000000]] value to evaluate its content.
Not all syntax values are supported by Zettelstore.[^Currently just ""[[draw|00001008050000]]"".]
The main reason for an evaluation block is to be used with external software via the [[ZJSON encoding|00001012920503]].

Any other character in this line will be ignored

Text following the beginning line will not be interpreted, until a line begins with at least the same number of the same characters given at the beginning line.
This allows to enter some tilde characters in the text that should not be interpreted.

For example:
`````zmk
~~~~
~~~
~~~~
`````
will be rendered in HTML as:
:::example
~~~~
~~~
~~~~
:::

`````zmk
~~~{-}
This is  some
text with no 
  real sense.
~~~~
`````
will be rendered as:
:::example
~~~{-}
This is  some
text with no 
  real sense.
~~~~
:::

`````zmk
~~~draw
+---+     +---+
| A | --> | B |
+---+     +---+
~~~
`````
will be rendered as:
:::example
~~~draw
+---+     +---+
| A | --> | B |
+---+     +---+
~~~
:::

id: 00001007031400
title: Zettelmarkup: Math-mode Blocks
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20220311182505

Math-mode blocks are used to enter mathematical formulas / equations in a display style mode.
Similar to a [[evaluation blocks|00001007031300]], the block content will be interpreted by either Zettelstore or an external software.
They begin with at least three dollar sign characters (""''$''"", U+0024) at the first position of a line.

You can add some [[attributes|00001007050000]] on the beginning line of a verbatim block, following the initiating characters.
A math-mode block supports the default attribute[^Depending on the syntax value.]: when given, all spaces in the text are rendered in HTML as open box characters (U+2423).
If you want to give only one attribute and this attribute is the generic attribute, you can omit the most of the attribute syntax and just specify the value.
It will be interpreted as a [[syntax|00001008000000]] value to evaluate its content.
Alternatively, you could provide an attribute with the key ""syntax"" and use the value to specify the syntax.
Not all syntax values are supported by Zettelstore.[^Currently: none.]
External software might support several values via the [[ZJSON encoding|00001012920503]].

Any other character in this line will be ignored

Text following the beginning line will not be interpreted, until a line begins with at least the same number of the same characters given at the beginning line.
This allows to enter some dollar-sign characters in the text that should not be interpreted.

For example:
`````zmk
$$$$
$$$
$$$$
`````
will be rendered in HTML as:
:::example
$$$$
$$$
$$$$
:::

`````zmk
$$${-}
This is  some
text with no 
  real sense.
$$$$
`````
will be rendered as:
:::example
$$${-}
This is  some
text with no 
  real sense.
$$$$
:::

In the future, Zettelstore might somehow support mathematical formulae with a $$\TeX$$-like syntax.
Until then,
`````zmk
$$$
\begin{align*}
  f(x) &= x^2\\
  g(x) &= \frac{1}{x}\\
  F(x) &= \int^a_b \frac{1}{3}x^3
\end{align*}
$$$
`````
is rendered as:
:::example
$$$
\begin{align*}
  f(x) &= x^2\\
  g(x) &= \frac{1}{x}\\
  F(x) &= \int^a_b \frac{1}{3}x^3
\end{align*}
$$$
:::

** Example: ``abc __def__ ghi`` is rendered in HTML as: ::abc __def__ ghi::{=example}.
* The asterisk character (""''*''"", U+002A) strongly emphasized its enclosed text.
** Example: ``abc **def** ghi`` is rendered in HTML as: ::abc **def** ghi::{=example}.
* The greater-than sign character (""''>''"", U+003E) marks text as inserted.
** Example: ``abc >>def>> ghi`` is rendered in HTML as: ::abc >>def>> ghi::{=example}.
* Similar, the tilde character (""''~''"", U+007E) marks deleted text.
** Example: ``abc ~~def~~ ghi`` is rendered in HTML as: ::abc ~~def~~ ghi::{=example}.
* The circumflex accent character (""''^''"", U+005E) allows to enter superscripted text.
* The circumflex accent character (""''^''"", U+005E) allows to enter super-scripted text.
** Example: ``e=mc^^2^^`` is rendered in HTML as: ::e=mc^^2^^::{=example}.
* The comma character (""'',''"", U+002C) produces subscripted text.
* The comma character (""'',''"", U+002C) produces sub-scripted text.
** Example: ``H,,2,,O`` is rendered in HTML as: ::H,,2,,O::{=example}.
* The quotation mark character (""''"''"", U+0022) marks an inline quotation, according to the [[specified language|00001007050100]].
** Example: ``""To be or not""`` is rendered in HTML as: ::""To be or not""::{=example}.
** Example: ``""Sein oder nicht""{lang=de}`` is rendered in HTML as: ::""Sein oder nicht""{lang=de}::{=example}.
* The colon character (""'':''"", U+003A) mark some text that should belong together. It fills a similar role as [[region blocks|00001007030800]], but just for inline elements.
** Example: ``abc ::def::{=example} ghi`` is rendered in HTML as: abc ::def::{=example} ghi.

id: 00001007040200
title: Zettelmarkup: Literal-like formatting
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20220218131420
modified: 20220311185110

There are some reasons to mark text that should be rendered as uninterpreted:
* Mark text as literal, sometimes as part of a program.
* Mark text as input you give into a computer via a keyboard.
* Mark text as output from some computer, e.g. shown at the command line.

=== Literal text

Attributes can be specified, the default attribute has the same semantic as for literal text.

=== Inline-zettel snippet
To specify an inline snippet in a different [[syntax|00001008000000]], delimit your text with two at-sign characters (""''@''"", U+0040) on each side.

You can add some [[attributes|00001007050000]] immediate after the two closing at-sign characters to specify the syntax to use.
Either use the attribute key ""syntax"" or use the generic attribute to specify the syntax value.
If no value is provided, ""draw"" is assumed.
If no value is provided, ""[[text|00001008000000#text]]"" is assumed.

Examples:
* ``A @@-->@@ B`` renders in HTML as ::A @@-->@@ B::{=example}.
* ``@@<small>@@{=html}Small@@</small>@@{=html}`` renders in HTML as ::@@<small>@@{=html}Small@@</small>@@{=html}::{=example}.

To some degree, an inline-zettel snippet is the @@<small>@@{=html}smaller@@</small>@@{=html} sibling of the [[inline-zettel block|00001007031200]].
For HTML syntax, the same rules apply.

=== Math mode / $$\TeX$$ input
This allows to enter text, that is typically interpreted by $$\TeX$$ or similar software.
The main difference to all other literal-like formatting above is that the backslash character (""''\\''"", U+005C) has no special meaning.
Therefore it is well suited the enter text with a lot of backslash characters.

Math mode text is delimited with two dollar signs (""''$''"", U+0024) on each side.

You can add some [[attributes|00001007050000]] immediate after the two closing at-sign characters to specify the syntax to use.
Either use the attribute key ""syntax"" or use the generic attribute to specify the syntax value.
If no syntax value is provided, math mode text roughly corresponds to literal text.

Currently, Zettelstore does not support any syntax.
This will probably change.
However, external software might support specific syntax value, like ""tex"", ""latex"", ""mathjax"", ""itex"", or ""webtex"".
Even an empty syntax value might be supported.

Example:
* ``Happy $$\\TeX$$!``is rendered as ::Happy $$\TeX$$!::{=example}

id: 00001007040324
title: Zettelmarkup: Inline-mode Transclusion
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20220131155955
modified: 20220311110814

Inline-mode transclusion applies to all zettel that are parsed in a non-trivial way, e.g. as structured textual content.
For example, textual content is assumed if the [[syntax|00001006020000#syntax]] of a zettel is ""zmk"" ([[Zettelmarkup|00001007000000]]), or ""markdown"" / ""md"" ([[Markdown|00001008010000]]).
If the syntax is ""[[draw|00001008050000]]"", it is also a non-trivial way.

Since this type of transclusion is at the level of [[inline-structured elements|00001007040000]], the transclude specification must be replaced with some inline-structured elements.

First, the referenced zettel is read.
If it contains other transclusions, these will be expanded, recursively.
When an endless recursion is detected, expansion does not take place.
Instead an error message replaces the transclude specification.

id: 00001007040340
title: Zettelmarkup: Citation Key
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20220218133447

A citation key references some external material that is part of a bibliografical collection.
A citation key references some external material that is part of a bibliographical collection.

Currently, Zettelstore implements this only partially, it is ""work in progress"".

However, the syntax is: beginning with a left square bracket and followed by an at sign character (""''@''"", U+0040), a the citation key is given.
The key is typically a sequence of letters and digits.
If a comma character (""'',''"", U+002C) or a vertical bar character is given, the following is interpreted as [[inline elements|00001007040000]].
A right square bracket ends the text and the citation key element.

id: 00001007050000
title: Zettelmarkup: Attributes
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20220218132935
modified: 20220630194106

Attributes allows to modify the way how material is presented.
Alternatively, they provide additional information to markup elements.
To some degree, attributes are similar to [[HTML attributes|https://html.spec.whatwg.org/multipage/dom.html#global-attributes]].

Typical use cases for attributes are to specify the (natural) [[language|00001007050100]] for a text region, to specify the [[programming language|00001007050200]] for highlighting program code, or to make white space visible in plain text.

The key ""''-''"" (just hyphen-minus) is special.
It is called __default attribute__ and has a markup specific meaning.
For example, when used for plain text, it replaces the non-visible space with a visible representation:

* ''``Hello, world``{-}'' produces ==Hello, world=={-}.
* ''``Hello, world``'' produces ==Hello, world==.

For some [[block-structured elements|00001007030000]], there is a syntax variant if you only want to specify a generic attribute.
For all line-range blocks you can specify the generic attributes directly in the first line, after the three (or more) block characters.

Attributes may be continued on the next line when a space or line ending character is possible.
```
:::attr
...
:::
```
is equivalent to
```
:::{=attr}
...
:::
```.

In case of a quoted attribute value, the line ending character will be part of the attribute value.
For other blocks, the closing curly bracket must be on the same line where the block element begins.
However, spaces are allowed between the blocks characters and the attributes.
```
=== Heading {example}
For example:
```
is allowed and equivalent to
{key="quoted
```
=== Heading{example}
```.
But
value"}
```
=== Heading {class=example
background=grey}
```
is not allowed. Same for
```
=== Heading {background=color:"
green"}
```.

will produce a value ''quoted\\nvalue'' (where \\n denotes a line ending character).
For [[inline-structued elements|00001007040000]], the attributes must immediately follow the inline markup.
However, the attributes may be continued on the next line when a space or line ending character is possible.

``::GREEN::{example}`` is allowed, but not ``::GREEN:: {example}``.

```
::GREEN::{class=example
background=grey}
```
is allowed, but not
```
::GREEN::{background=color:
green}
```.

However,
```
::GREEN::{background=color:"
green"}
```
is allowed, because line endings are allowed within quotes.

For [[block-structured elements|00001007030000]], there is a syntax variant if you only want to specify a generic attribute.
For all line-range blocks you can specify the generic attributes directly in the first line, after the three (or more) characters starting the block.

```
:::attr
...
:::
```
is equivalent to
```
:::{=attr}
...
:::
```.

For block-structured elements, spaces are allowed between the blocks characters and the attributes.
```
=== Heading {example}
```
is allowed and equivalent to
```
=== Heading{example}
```.

For [[inline-structured elements|00001007040000]], the attributes must immediately follow the inline markup.

``::GREEN::{example}`` is allowed, but not ``::GREEN:: {example}``.


=== Reference material
* [[Supported attribute values for natural languages|00001007050100]]
* [[Supported attribute values for programming languages|00001007050200]]

id: 00001007060000
title: Zettelmarkup: Summary of Formatting Characters
role: manual
tags: #manual #reference #zettelmarkup #zettelstore
syntax: zmk
modified: 20220218124943
modified: 20220311120759

The following table gives an overview about the use of all characters that begin a markup element.

|= Character :|= [[Blocks|00001007030000]] <|= [[Inlines|00001007040000]] <
| ''!''  | (free) | (free)
| ''"''  | [[Verse block|00001007030700]] | [[Short inline quote|00001007040100]]
| ''#''  | [[Ordered list|00001007030200]] | [[Tag|00001007040000]]
| ''$''  | (reserved) | (reserved)
| ''%''  | [[Comment block|00001007030900]] | [[Comment|00001007040000]]
| ''&''  | (free) | [[Entity|00001007040000]]
| ''\'''  | (free)  | [[Computer input|00001007040200]]
| ''(''  | (free) | (free)
| '')''  | (free) | (free)
| ''*''  | [[Unordered list|00001007030200]] | [[strongly emphasized text|00001007040100]]
| ''+''  | (free) | (free)
| '',''  | (free) | [[Subscripted text|00001007040100]]
| ''-''  | [[Horizonal rule|00001007030400]] | ""[[en-dash|00001007040000]]""
| '',''  | (free) | [[Sub-scripted text|00001007040100]]
| ''-''  | [[Horizontal rule|00001007030400]] | ""[[en-dash|00001007040000]]""
| ''.''  | (free) | [[Horizontal ellipsis|00001007040000]]
| ''/''  | (free) | (free)
| '':''  | [[Region block|00001007030800]] / [[description text|00001007030100]] | [[Inline region|00001007040100]]
| '';''  | [[Description term|00001007030100]] | [[Small text|00001007040100]]
| ''<''  | [[Quotation block|00001007030600]] | (free)
| ''=''  | [[Headings|00001007030300]] | [[Computer output|00001007040200]]
| ''>''  | [[Quotation lists|00001007030200]] | [[Inserted text|00001007040100]]
| ''?''  | (free) | (free)
| ''@''  | [[Inline-Zettel blocks|00001007031200]] | [[Inline-zettel snippets|00001007040200#inline-zettel-snippet]]
| ''@''  | [[Inline-Zettel block|00001007031200]] | [[Inline-zettel snippet|00001007040200#inline-zettel-snippet]]
| ''[''  | (reserved)  | [[Linked material|00001007040300]], [[citation key|00001007040300]], [[footnote|00001007040300]], [[mark|00001007040300]]
| ''\\'' | (blocked by inline meaning) | [[Escape character|00001007040000]]
| '']''  | (reserved) | End of [[link|00001007040300]], [[citation key|00001007040300]], [[footnote|00001007040300]], [[mark|00001007040300]]
| ''^''  | (free) | [[Superscripted text|00001007040100]]
| ''^''  | (free) | [[Super-scripted text|00001007040100]]
| ''_''  | (free) | [[Emphasized text|00001007040100]]
| ''`''  | [[Verbatim block|00001007030500]] | [[Literal text|00001007040200]]
| ''{''  | [[Transclusion|00001007031100]] | [[Embedded material|00001007040300]], [[Attribute|00001007050000]]
| ''|''  | [[Table row / table cell|00001007031000]] | Separator within link and [[embed|00001007040320]] formatting
| ''}''  | End of [[Transclusion|00001007031100]] | End of embedded material, End of Attribute
| ''~''  | (free) | [[Deleted text|00001007040100]]
| ''~''  | [[Evaluation block|00001007031300]] | [[Deleted text|00001007040100]]

id: 00001008000000
title: Other Markup Languages
role: manual
tags: #manual #zettelstore
syntax: zmk
modified: 20220214180202
modified: 20220627192329

[[Zettelmarkup|00001007000000]] is not the only markup language you can use to define your content.
Zettelstore is quite agnostic with respect to markup languages.
Of course, Zettelmarkup plays an important role.
However, with the exception of zettel titles, you can use any (markup) language that is supported:

* CSS
* HTML template data
* Image formats: GIF, PNG, JPEG, SVG
* Markdown
* Plain text, not further interpreted

The [[metadata key|00001006020000#syntax]] ""''syntax''"" specifies which language should be used.
If it is not given, the key ""''default-syntax''"" will be used (specified in the [[configuration zettel|00001004020000#default-syntax]]).
If it is not given, it defaults to ''plain''.
The following syntax values are supported:

; [!css|''css'']
: A [[Cascading Style Sheet|https://www.w3.org/Style/CSS/]], to be used when rendering a zettel as HTML.
; [!draw|''draw'']
: A simple [[language|00001008050000]] to ""draw"" a graphic by using some simple Unicode characters.
; [!gif|''gif'']; [!jpeg|''jpeg'']; [!jpg|''jpg'']; [!png|''png'']
: The formats for pixel graphics.
  Typically the data is stored in a separate file and the syntax is given in the metafile, which has the same name as the zettel identifier and has no file extension.[^Before version 0.2.0, the metafile had the file extension ''.meta'']
  Typically the data is stored in a separate file and the syntax is given in the meta-file, which has the same name as the zettel identifier and has no file extension.[^Before version 0.2, the meta-file had the file extension ''.meta'']
; [!html|''html'']
: Hypertext Markup Language, will not be parsed further.
  Instead, it is treated as [[text|#text]], but will be encoded differently for [[HTML format|00001012920510]] (same for the [[web user interface|00001014000000]]).

  For security reasons, equivocal elements will not be encoded in the HTML format / web user interface, e.g. the ``<script ...`` tag.
  For security reasons, equivocal elements will not be encoded in the HTML format / web user interface.
  The ``< script ...>`` tag is an example.
  See [[security aspects of Markdown|00001008010000#security-aspects]] for some details.
; [!markdown|''markdown''], [!md|''md'']
: For those who desperately need [[Markdown|https://daringfireball.net/projects/markdown/]].
  Since the world of Markdown is so diverse, a [[CommonMark|00001008010500]] parser is used.
  See [[Use Markdown within Zettelstore|00001008010000]].
; [!mustache|''mustache'']
: A [[Mustache template|https://mustache.github.io/]], used when rendering a zettel as HTML for the [[web user interface|00001014000000]].

: Just plain text that must not be interpreted further.
; [!zmk|''zmk'']
: [[Zettelmarkup|00001007000000]].

The actual values are also listed in a zettel named [[Zettelstore Supported Parser|00000000000092]].

If you specify something else, your content will be interpreted as plain text.

=== Language for other elements of a zettel
[[Zettelmarkup|00001007000000]] allows to specify [[evaluation blocks|00001007031300]], which also receive a syntax value.
An evaluation blocks is typically interpreted by external software, for example [[Zettel Presenter|00001006055000#external-applications]].
However, some values are interpreted by Zettelstore during evaluation of a zettel:
; [!draw|''draw'']
: A [[language|00001008050000]] to ""draw"" a graphic by using some simple Unicode characters.

id: 00001008010000
title: Use Markdown within Zettelstore
role: manual
tags: #manual #markdown #zettelstore
syntax: zmk
modified: 20220113185400
modified: 20220627192014

If you are customized to use Markdown as your markup language, you can configure Zettelstore to support your decision.
Zettelstore supports the [[CommonMark|00001008010500]] dialect of Markdown.

=== Use Markdown as the default markup language of Zettelstore

Add the key ''default-syntax'' with a value of ''md'' or ''markdown'' to the [[configuration zettel|00000000000100]].
Update the [[New Zettel|00000000090001]] template (and other relevant template zettel) by setting the syntax value to ''md'' or ''markdown''.
Whether to use ''md'' or ''markdown'' is not just a matter to taste.
It also depends on the value of [[''zettel-file-syntax''|00001004020000#zettel-file-syntax]] and, to some degree, on the value of [[''yaml-header''|00001004020000#yaml-header]].

If you set ''yaml-header'' to true, then new content is always stored in a file with the extension ''.zettel''.

Otherwise ''zettel-file-syntax'' lists all syntax values, where its content should be stored in a file with the extension ''.zettel''.

If neither ''yaml-header'' nor ''zettel-file-syntax'' is set, new content is stored in a file where its file name extension is the same as the syntax value of that zettel.
In this case it makes a difference, whether you specify ''md'' or ''markdown''.
If you specify the syntax ''md'', your content will be stored in a file with the ''.md'' extension.
Similar for the syntax ''markdown''.

If you want to process the files that store the zettel content, e.g. with some other Markdown tools, this may be important.
Not every Markdown tool allows both file extensions.

BTW, metadata is stored in a file without a file extension, if neither ''yaml-header'' nor ''zettel-file-syntax'' is set.

=== Security aspects

You should be aware that Markdown is a superset of HTML.
You should be aware that Markdown is a super-set of HTML.
Any HTML code is valid Markdown code.
If you write your own zettel, this is probably not a problem.

However, if you receive zettel from others, you should be careful.
An attacker might include malicious HTML code in your zettel.
For example, HTML allows to embed JavaScript, a full-sized programming language that drives many web sites.
When a zettel is displayed, JavaScript code might be executed, sometimes with harmful results.

But they provide proprietary extensions, which makes it harder to change to another CommonMark implementation if needed.
Plus, they sometimes build on an older specification of CommonMark.

Zettelstore supports the latest CommonMark [[specification version 0.30 (2021-06-19)|https://spec.commonmark.org/0.30/]].
If possible, Zettelstore will adapt to newer versions when they are available.

To provide CommonMark support, Zettelstore uses currently the [[Goldmark|https://github.com/yuin/goldmark]] implementation, which passes all validation tests of CommonMark.
Internally, CommonMark is translated into some kind of superset of [[Zettelmarkup|00001007000000]], which additionally allows to use HTML code.[^Effectively, Markdown and CommonMark are itself supersets of HTML.]
This Zettelmarkup superset is later [[encoded|00001012920500]], often into [[HTML|00001012920510]].
Internally, CommonMark is translated into some kind of super-set of [[Zettelmarkup|00001007000000]], which additionally allows to use HTML code.[^Effectively, Markdown and CommonMark are itself super-sets of HTML.]
This Zettelmarkup super-set is later [[encoded|00001012920500]], often into [[HTML|00001012920510]].
Because Zettelstore HTML encoding philosophy differs a little bit to that of CommonMark, Zettelstore itself will not pass the CommonMark test suite fully.
However, no CommonMark language element will fail to be encoded as HTML.
In most cases, the differences are not visible for an user, but only by comparing the generated HTML code.

id: 00001008050000
title: The ""draw"" language
role: manual
tags: #graphic #manual #zettelstore
syntax: zmk
modified: 20220217180713
modified: 20220311120439

Sometimes, ""a picture is worth a thousand words"".
To create some graphical representations, Zettelstore provides a simple mechanism.
To create some graphical representations, Zettelmarkup provides a simple mechanism.
Characters like ""''|''"" or ""''-''"" already provide some visual feedback.
For example, to create a picture containing two boxes that are connected via an arrow, the following representation is possible:
```
~~~draw
+-------+       +-------+
+-------+       .-------.
| Box 1 | ----> | Box 2 |
+-------+       +-------+
+-------+       '-------'
~~~
```
Zettelstore translates this to:
@@@draw
+-------+       +-------+
~~~draw
+-------+       .-------.
| Box 1 | ----> | Box 2 |
+-------+       +-------+
+-------+       '-------'
@@@
~~~

Technically spoken, the drawing is translated to a [[SVG|00001008000000#svg]] element.

The following characters are interpreted to create a graphical representation.
Some of them will start a path that results in a recognized object.

|=Character:|Meaning|Path Start:

Or you want to allow them to create new zettel, or to change them.
It is up to you.

If someone is authenticated as the owner of the Zettelstore (hopefully you), no restrictions apply.
But as an owner, you can create ""user zettel"" to allow others to access your Zettelstore in various ways.
Even if you do not want to share your Zettelstore with other persons, creating user zettel can be useful if you plan to access your Zettelstore via the [[API|00001012000000]].

Additionally, you can specify that a zettel is publicily visible.
Additionally, you can specify that a zettel is publicly visible.
In this case no one has to authenticate itself to see the content of the zettel.
Or you can specify that a zettel is visible only to the owner.
In this case, no authenticated user will be able to read and change that protected zettel.

* [[Visibility rules for zettel|00001010070200]]
* [[User roles|00001010070300]] define basic rights of an user
* [[Authorization and read-only mode|00001010070400]]

id: 00001010040100
title: Enable authentication
role: manual
tags: #authentication #configuration #manual #security #zettelstore
syntax: zmk
modified: 20220419192817

To enable authentication, you must create a zettel that stores [[authentication data|00001010040200]] for the owner.
Then you must reference this zettel within the [[startup configuration|00001004010000#owner]] under the key ''owner''.
Once the startup configuration contains a valid [[zettel identifier|00001006050000]] under that key, authentication is enabled.

Please note that you must also set key ''secret'' of the [[startup configuration|00001004010000#secret]] to some random string data (minimum length is 16 bytes) to secure the data exchanged with a client system.

id: 00001012000000
title: API
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20220304173249
modified: 20220627183444

The API (short for ""**A**pplication **P**rogramming **I**nterface"") is the primary way to communicate with a running Zettelstore.
Most integration with other systems and services is done through the API.
The [[web user interface|00001014000000]] is just an alternative, secondary way of interacting with a Zettelstore.

=== Background
The API is HTTP-based and uses plain text and JSON as its main encoding format for exchanging messages between a Zettelstore and its client software.

=== Zettel lists
* [[List metadata of all zettel|00001012051200]]
* [[Shape the list of zettel metadata|00001012051800]]
** [[Selection of zettel|00001012051810]]
** [[Limit the list length|00001012051830]]
** [[Content search|00001012051840]]
** [[Sort the list of zettel metadata|00001012052000]]
* [[List all tags|00001012052400]]
* [[Map metadata values to lists of zettel identifier|00001012052400]]
* [[List all roles|00001012052600]]

=== Working with zettel
* [[Create a new zettel|00001012053200]]
* [[Retrieve metadata and content of an existing zettel|00001012053300]]
* [[Retrieve metadata of an existing zettel|00001012053400]]
* [[Retrieve evaluated metadata and content of an existing zettel in various encodings|00001012053500]]
* [[Retrieve parsed metadata and content of an existing zettel in various encodings|00001012053600]]

id: 00001012052400
title: API: List all tags
title: API: Map metadata values to list of zettel identifier
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20220627183323

The [[endpoint|00001012920000]] ''/m'' allows to retrieve a map of metadata values (of a specific key) to the list of zettel identifier, which reference zettel containing this value under the given metadata key.
To list all [[tags|00001006020000#tags]] used in the Zettelstore just send a HTTP GET request to the [[endpoint|00001012920000]] ''/t''.

Currently, two keys are supported:
* [[''role''|00001006020100]]
* [[''tags''|00001006020000#tags]]

To list all roles used in the Zettelstore, send a HTTP GET request to the endpoint ''/m?_key=role''.
If successful, the output is a JSON object:

```sh
# curl http://127.0.0.1:23123/m?_key=role
{"map":{"configuration":["00000000090002","00000000090000", ... ,"00000000000001"],"manual":["00001014000000", ... ,"00001000000000"],"zettel":["00010000000000", ... ,"00001012070500","00000000090001"]}}
```

The JSON object only contains the key ''"map"'' with the value of another object.
This second object contains all role names as keys and the list of identifier of those zettel with this specific role as a value.

Similar, to list all tags used in the Zettelstore, send a HTTP GET request to the endpoint ''/m?_key=tags''.
If successful, the output is a JSON object:

```sh
# curl http://127.0.0.1:23123/t
{"tags":{"#api":[:["00001012921000","00001012920800","00001012920522",...],"#authorization":["00001010040700","00001010040400",...],...,"#zettelstore":["00010000000000","00001014000000",...,"00001001000000"]}}
# curl http://127.0.0.1:23123/m?_key=tags
{"map":{"#api":[:["00001012921000","00001012920800","00001012920522",...],"#authorization":["00001010040700","00001010040400",...],...,"#zettelstore":["00010000000000","00001014000000",...,"00001001000000"]}}
```

The JSON object only contains the key ''"tags"'' with the value of another object.
The JSON object only contains the key ''"map"'' with the value of another object.
This second object contains all tags as keys and the list of identifier of those zettel with this tag as a value.

Please note that this structure will likely change in the future to be more compliant with other API calls.

id: 00001012052600
title: API: List all roles
role: manual
tags: #api #manual #zettelstore
syntax: zmk

To list all [[roles|00001006020100]] used in the Zettelstore just send a HTTP GET request to the [[endpoint|00001012920000]] ''/r''.
If successful, the output is a JSON object:

```sh
# curl http://127.0.0.1:23123/r
{"role-list":["configuration","manual","user","zettel"]}
```

The JSON object only contains the key ''"role-list"'' with the value of a sorted string list.
Each string names one role.

Please note that this structure will likely change in the future to be more compliant with other API calls.

id: 00001012053200
title: API: Create a new zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20211124180030
modified: 20220628111320

A zettel is created by adding it to the [[list of zettel|00001012000000#zettel-lists]].
Therefore, the [[endpoint|00001012920000]] to create a new zettel is also ''/j'', but you must send the data of the new zettel via a HTTP POST request.

The body of the POST request must contain a JSON object that specifies metadata and content of the zettel to be created.
The following keys of the JSON object are used:
; ''"meta"''

  Typically, text content is not encoded, and binary content is encoded via Base64.

Other keys will be ignored.
Even these three keys are just optional.
The body of the HTTP POST request must not be empty and it must contain a JSON object.

Therefore, a body containing just ''{}'' is perfectly valid.
The new zettel will have no content, its title will be set to the value of [[''default-title''|00001004020000#default-title]] (default: ""Untitled""), its role is set to the value of [[''default-role''|00001004020000#default-role]] (default: ""zettel""), and its syntax is set to the value of [[''default-syntax''|00001004020000#default-syntax]] (default: ""zmk"").
The new zettel will have no content, and only an identifier as [[metadata|00001006020000]]:

```
# curl -X POST --data '{}' http://127.0.0.1:23123/j
{"id":"20210713161000"}
```
If creating the zettel was successful, the HTTP response will contain a JSON object with one key:
; ''"id"''

id: 00001012053300
title: API: Retrieve metadata and content of an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20220201180121
modified: 20220724163741

The [[endpoint|00001012920000]] to work with metadata and content of a specific zettel is ''/j/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]].

For example, to retrieve some data about this zettel you are currently viewing, just send a HTTP GET request to the endpoint ''/j/00001012053300''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header].
If successful, the output is a JSON object:
```sh
# curl http://127.0.0.1:23123/j/00001012053300
{"id":"00001012053300","meta":{"title":"API: Retrieve data for an exisiting zettel","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual","copyright":"(c) 2020 by Detlef Stern <ds@zettelstore.de>","lang":"en","license":"CC BY-SA 4.0"},"content":"The endpoint to work with a specific zettel is ''/j/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000}}.\n\nFor example, ...
{"id":"00001012053300","meta":{"title":"API: Retrieve data for an existing zettel","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual","copyright":"(c) 2020 by Detlef Stern <ds@zettelstore.de>","lang":"en","license":"CC BY-SA 4.0"},"content":"The endpoint to work with a specific zettel is ''/j/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000}}.\n\nFor example, ...
```

Pretty-printed, this results in:
```
{
  "id": "00001012053300",
  "meta": {

  Other values will result in a HTTP response status code ''400''.
; ''"content"''
: Is a string value that contains the content of the zettel to be created.
  Typically, text content is not encoded, and binary content is encoded via Base64.
; ''"rights"''
: An integer number that describes the [[access rights|00001012921200]] for the zettel.

=== Plain zettel
[!plain]Additionally, you can retrieve the plain zettel, without using JSON.
Just change the [[endpoint|00001012920000]] to ''/z/{ID}''
Optionally, you may provide which parts of the zettel you are requesting.
In this case, add an additional query parameter ''_part=[[PART|00001012920800]]''.
Valid values are ""zettel"", ""[[meta|00001012053400]]"", and ""content"" (the default value).

````sh

id: 00001012053500
title: API: Retrieve evaluated metadata and content of an existing zettel in various encodings
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20220301174012
modified: 20220410153546

The [[endpoint|00001012920000]] to work with evaluated metadata and content of a specific zettel is ''/v/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]].

For example, to retrieve some evaluated data about this zettel you are currently viewing, just send a HTTP GET request to the endpoint ''/v/00001012053500''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header].
If successful, the output is a JSON object:
```sh
# curl http://127.0.0.1:23123/v/00001012053500

<meta name="zs-box-number" content="1">
<meta name="copyright" content="(c) 2020-2021 by Detlef Stern <ds@zettelstore.de>">
<meta name="zs-forward" content="00001010040100 00001012050200 00001012920000 00001012920800">
<meta name="zs-lang" content="en">
<meta name="zs-published" content="00001012053500">
```

The optional query parameter ''_embed'' will embed all images into the returned encoding.

=== HTTP Status codes
; ''200''
: Retrieval was successful, the body contains an appropriate JSON object.
; ''400''
: Request was not valid. 
  There are several reasons for this.
  Maybe the zettel identifier did not consist of exactly 14 digits or ''_enc'' / ''_part'' contained illegal values.
; ''403''
: You are not allowed to retrieve data of the given zettel.
; ''404''
: Zettel not found.
  You probably used a zettel identifier that is not used in the Zettelstore.

id: 00001012920000
title: Endpoints used by the API
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
modified: 20220304173423
modified: 20220627183408

All API endpoints conform to the pattern ''[PREFIX]LETTER[/ZETTEL-ID]'', where:
; ''PREFIX''
: is the URL prefix (default: ""/""), configured via the ''url-prefix'' [[startup configuration|00001004010000]],
; ''LETTER''
: is a single letter that specifies the resource type,
; ''ZETTEL-ID''
: is an optional 14 digits string that uniquely [[identify a zettel|00001006050000]].

The following letters are currently in use:

|= Letter:| Without zettel identifier | With [[zettel identifier|00001006050000]] | Mnemonic
| ''a'' | POST: [[client authentication|00001012050200]] | | **A**uthenticate
|       | PUT: [[renew access token|00001012050400]] |
| ''j'' | GET: [[list zettel AS JSON|00001012051200]] | GET: [[retrieve zettel AS JSON|00001012053300]] | **J**SON
|       | POST: [[create new zettel|00001012053200]] | PUT: [[update a zettel|00001012054200]]
|       |  | DELETE: [[delete the zettel|00001012054600]]
|       |  | MOVE: [[rename the zettel|00001012054400]]
| ''m'' |  | GET: [[retrieve metadata|00001012053400]] | **M**etadata
| ''m'' | GET: [[map metadata values|00001012052400]] | GET: [[retrieve metadata|00001012053400]] | **M**etadata
| ''o'' |  | GET: [[list zettel order|00001012054000]] | **O**rder
| ''p'' |  | GET: [[retrieve parsed zettel|00001012053600]]| **P**arsed
| ''r'' | GET: [[list roles|00001012052600]] | | **R**oles
| ''t'' | GET: [[list tags|00001012052400]] || **T**ags
| ''u'' |  | GET [[unlinked references|00001012053900]] | **U**nlinked
| ''v'' |  | GET: [[retrieve evaluated zettel|00001012053500]] | E**v**aluated
| ''x'' | GET: [[retrieve administrative data|00001012070500]] | GET: [[list zettel context|00001012053800]] | Conte**x**t
|       | POST: [[execute command|00001012080100]]
| ''z'' | GET: [[list zettel|00001012051200#plain]] | GET: [[retrieve zettel|00001012053300#plain]] | **Z**ettel
|       | POST: [[create new zettel|00001012053200#plain]] | PUT: [[update a zettel|00001012054200#plain]]
|       |  | DELETE: [[delete zettel|00001012054600#plain]]
|       |  | MOVE: [[rename zettel|00001012054400#plain]]

The full URL will contain either the ""http"" oder ""https"" scheme, a host name, and an optional port number.

The API examples will assume the ""http"" schema, the local host ""127.0.0.1"", the default port ""23123"", and the default empty ''PREFIX'' ""/"".
Therefore, all URLs in the API documentation will begin with ""http://127.0.0.1:23123/"".

id: 00001012920500
title: Encodings available via the [[API|00001012000000]]
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
modified: 20220209114459
modified: 20220423131535

A zettel representation can be encoded in various formats for further processing.

* [[zjson|00001012920503]] (default)
* [[html|00001012920510]]
* [[native|00001012920513]]
* [[sexpr|00001012920516]]
* [[text|00001012920519]]
* [[zjson|00001012920503]] (default)
* [[zmk|00001012920522]]

id: 00001012920503
title: ZJSON Encoding
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
modified: 20220223185826
modified: 20220422191748

A zettel representation that allows to process the syntactic structure of a zettel.
It is a JSON-based encoding format, but different to the structures returned by [[endpoint|00001012920000]] ''/j/{ID}''.

For an example, take a look at the JSON encoding of this page, which is available via the ""Info"" sub-page of this zettel: 
For an example, take a look at the ZJSON encoding of this page, which is available via the ""Info"" sub-page of this zettel: 

* [[//v/00001012920503?_enc=zjson&_part=zettel]],
* [[//v/00001012920503?_enc=zjson&_part=meta]],
* [[//v/00001012920503?_enc=zjson&_part=content]].

If transferred via HTTP, the content type will be ''application/json''.

id: 00001012920513
title: Native Encoding
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
modified: 20210726193049

A zettel representation shows the structure of a zettel in a more user-friendly way.
Mostly used for debugging.

If transferred via HTTP, the content type will be ''text/plain''.

TODO: formal description

id: 00001012920516
title: Sexpr Encoding
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
modified: 20220724170637

A zettel representation that is a [[s-expression|https://en.wikipedia.org/wiki/S-expression]] (also known as symbolic expression).

It is an alternative to the [[ZJSON encoding|00001012920503]].
Both encodings are (relatively) easy to parse and contain all relevant information of a zettel, metadata and content.

For example, take a look at the Sexpr encoding of this page, which is available via the ""Info"" sub-page of this zettel: 

* [[//v/00001012920516?_enc=sexpr&_part=zettel]],
* [[//v/00001012920516?_enc=sexpr&_part=meta]],
* [[//v/00001012920516?_enc=sexpr&_part=content]].

If transferred via HTTP, the content type will be ''text/plain''.

=== Syntax of s-expressions
There are only two types of elements: atoms and lists.

A list always starts with the left parenthesis (""''(''"", U+0028) and ends with a right parenthesis (""'')''"", U+0029).
A list may contain a possibly empty sequence of elements, i.e. lists and / or atoms.

There are three syntactic forms for an atom: numbers, symbols and strings.

A number is a non-empty sequence of digits (""0"" ... ""9"").
The smallest number is ``0``, there are no negative numbers.

A symbol is a non-empty sequence of printable characters, except left or right parenthesis.
Unicode characters of the following categories contains printable characters in the above sense: letter (L), number (N), punctuation (P), symbol (S).
Symbols are case-insensitive, i.e. ""''ZETTEL''"" and ""''zettel''"" denote the same symbol.

A string starts with a quotation mark (""''"''"", U+0022), contains a possibly empty sequence of Unicode characters, and ends with a quotation mark.
To allow a string to contain a quotations mark, it must be prefixed by one backslash (""''\\''"", U+005C).
To allow a string to contain a backslash, it also must be prefixed by one backslash.
Unicode characters with a code less than U+FF are encoded by by the sequence ""''\\xNM''"", where ''NM'' is the hex encoding of the character.
Unicode characters with a code less than U+FFFF are encoded by by the sequence ""''\\uNMOP''"", where ''NMOP'' is the hex encoding of the character.
Unicode characters with a code less than U+FFFFFF are encoded by by the sequence ""''\\UNMOPQR''"", where ''NMOPQR'' is the hex encoding of the character.
In addition, the sequence ""''\\t''"" encodes a horizontal tab (U+0009), the sequence ""''\\n''"" encodes a line feed (U+000A).

Atoms are separated by Unicode characters of category separator (Z).

id: 00001012920519
title: Text Encoding
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
modified: 20210726193119

A zettel representation contains just all textual data of a zettel.
Could be used for creating a search index.

Every line may contain zero, one, or more words, spearated by space character.
Every line may contain zero, one, or more words, separated by space character.

If transferred via HTTP, the content type will be ''text/plain''.

id: 00001012921000
title: API: JSON structure of an access token
tags: #api #manual #reference #zettelstore
syntax: zmk
role: manual

If the [[authentiction process|00001012050200]] was successful, an access token with some additional data is returned.
If the [[authentication process|00001012050200]] was successful, an access token with some additional data is returned.
The same is true, if the access token was [[renewed|00001012050400]].
The response is structured as an JSON object, with the following named values:

|=Name|Description
|''access_token''|The access token itself, as string value, which is a [[JSON Web Token|https://tools.ietf.org/html/rfc7519]] (JWT, RFC 7915)
|''token_type''|The type of the token, always set to ''"Bearer"'', as described in [[RFC 6750|https://tools.ietf.org/html/rfc6750]]
|''expires_in''|An integer that gives a hint about the lifetime / endurance of the token, measured in seconds

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2021 Detlef Stern
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package id provides domain specific types, constants, and functions about

	FormTemplateZid    = MustParse(api.ZidFormTemplate)
	RenameTemplateZid  = MustParse(api.ZidRenameTemplate)
	DeleteTemplateZid  = MustParse(api.ZidDeleteTemplate)
	ContextTemplateZid = MustParse(api.ZidContextTemplate)
	RolesTemplateZid   = MustParse(api.ZidRolesTemplate)
	TagsTemplateZid    = MustParse(api.ZidTagsTemplate)
	ErrorTemplateZid   = MustParse(api.ZidErrorTemplate)
	RoleCSSMapZid      = MustParse(api.ZidRoleCSSMap)
	EmojiZid           = MustParse(api.ZidEmoji)
	TOCNewTemplateZid  = MustParse(api.ZidTOCNewTemplate)
	DefaultHomeZid     = MustParse(api.ZidDefaultHome)
)

const maxZid = 99999999999999

//-----------------------------------------------------------------------------
// Copyright (c) 2022 Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

package meta

import "sort"

// Arrangement stores metadata within its categories.
// Typecally a category might be a tag name, a role name, a syntax value.
type Arrangement map[string][]*Meta

// CreateArrangement by inspecting a given key and use the found
// value as a category.
func CreateArrangement(metaList []*Meta, key string) Arrangement {
	if len(metaList) == 0 {
		return nil
	}
	descr := Type(key)
	if descr == nil {
		return nil
	}
	a := make(Arrangement)
	if descr.IsSet {
		for _, m := range metaList {
			if vals, ok := m.GetList(key); ok {
				for _, val := range vals {
					a[val] = append(a[val], m)
				}
			}
		}
	} else {
		for _, m := range metaList {
			if val, ok := m.Get(key); ok && val != "" {
				a[val] = append(a[val], m)
			}
		}
	}
	return a
}

// Counted returns the list of categories, together with the number of
// metadata for each category.
func (a Arrangement) Counted() CountedCategories {
	if len(a) == 0 {
		return nil
	}
	result := make(CountedCategories, 0, len(a))
	for cat, metas := range a {
		result = append(result, CountedCategory{Name: cat, Count: len(metas)})
	}
	return result
}

// CountedCategory contains of a name and the number how much this name occured
// somewhere.
type CountedCategory struct {
	Name  string
	Count int
}

// CountedCategories is the list of CountedCategories.
// Every name must occur only once.
type CountedCategories []CountedCategory

// SortByName sorts the list by the name attribute.
// Since each name must occur only once, two CountedCategories cannot have
// the same name.
func (ccs CountedCategories) SortByName() {
	sort.Slice(ccs, func(i, j int) bool { return ccs[i].Name < ccs[j].Name })
}

// SortByCount sorts the list by the count attribute, descending.
// If two counts are equal, elements are sorted by name.
func (ccs CountedCategories) SortByCount() {
	sort.Slice(ccs, func(i, j int) bool {
		iCount, jCount := ccs[i].Count, ccs[j].Count
		if iCount > jCount {
			return true
		}
		if iCount == jCount {
			return ccs[i].Name < ccs[j].Name
		}
		return false
	})
}

// Categories returns just the category names.
func (ccs CountedCategories) Categories() []string {
	result := make([]string, len(ccs))
	for i, cc := range ccs {
		result[i] = cc.Name
	}
	return result
}

	"regexp"
	"sort"
	"strings"
	"unicode"
	"unicode/utf8"

	"zettelstore.de/c/api"
	"zettelstore.de/c/maps"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/input"
	"zettelstore.de/z/strfun"
)

type keyUsage int

		return *d
	}
	return DescriptionKey{Type: Type(name)}
}

// GetSortedKeyDescriptions delivers all metadata key descriptions as a slice, sorted by name.
func GetSortedKeyDescriptions() []*DescriptionKey {
	names := make([]string, 0, len(registeredKeys))
	for n := range registeredKeys {
	keys := maps.Keys(registeredKeys)
		names = append(names, n)
	}
	sort.Strings(names)
	result := make([]*DescriptionKey, 0, len(names))
	for _, n := range names {
	result := make([]*DescriptionKey, 0, len(keys))
	for _, n := range keys {
		result = append(result, registeredKeys[n])
	}
	return result
}

// Supported keys.
func init() {

// Set stores the given string value under the given key.
func (m *Meta) Set(key, value string) {
	if key != api.KeyID {
		m.pairs[key] = trimValue(value)
	}
}

// SetNonEmpty stores the given value under the given key, if the value is non-empty.
// An empty value will delete the previous association.
func (m *Meta) SetNonEmpty(key, value string) {
	if value == "" {
		delete(m.pairs, key)
	} else if key != api.KeyID {
		m.pairs[key] = trimValue(value)
	}
}

func trimValue(value string) string {
	return strings.TrimFunc(value, input.IsSpace)
}

// Get retrieves the string value of a given key. The bool value signals,
// whether there was a value stored or not.

// stored, the given default value is returned.
func (m *Meta) GetDefault(key, def string) string {
	if value, ok := m.Get(key); ok {
		return value
	}
	return def
}

// GetTitle returns the title of the metadata. It is the only key that has a
// defined default value: the string representation of the zettel identifier.
func (m *Meta) GetTitle() string {
	if title, found := m.Get(api.KeyTitle); found {
		return title
	}
	return m.Zid.String()
}

// Pairs returns not computed key/values pairs stored, in a specific order.
// First come the pairs with predefined keys: MetaTitleKey, MetaTagsKey, MetaSyntaxKey,
// MetaContextKey. Then all other pairs are append to the list, ordered by key.
func (m *Meta) Pairs() []Pair {
	return m.doPairs(m.getFirstKeys(), notComputedKey)
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package meta provides the domain specific type 'meta'.

		}
	}
}

func TestTitleHeader(t *testing.T) {
	t.Parallel()
	m := New(testID)
	if got, ok := m.Get(api.KeyTitle); ok || got != "" {
	if got, ok := m.Get(api.KeyTitle); ok && got != "" {
		t.Errorf("Title is not empty, but %q", got)
	}
	addToMeta(m, api.KeyTitle, " ")
	if got, ok := m.Get(api.KeyTitle); ok || got != "" {
	if got, ok := m.Get(api.KeyTitle); ok && got != "" {
		t.Errorf("Title is not empty, but %q", got)
	}
	const st = "A simple text"
	addToMeta(m, api.KeyTitle, " "+st+"  ")
	if got, ok := m.Get(api.KeyTitle); !ok || got != st {
		t.Errorf("Title is not %q, but %q", st, got)
	}

// under this license.
//-----------------------------------------------------------------------------

// Package meta provides the domain specific type 'meta'.
package meta

import (
	"sort"
	"strings"

	"zettelstore.de/c/api"
	"zettelstore.de/c/maps"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/input"
	"zettelstore.de/z/strfun"
)

// NewFromInput parses the meta data of a zettel.
func NewFromInput(zid id.Zid, inp *input.Input) *Meta {

	set := make(strfun.Set, len(newElems)+len(oldElems))
	addToSet(set, newElems, useElem)
	if len(set) == 0 {
		// Nothing to add. Maybe because of rejected elements.
		return
	}
	addToSet(set, oldElems, useElem)

	resultList := make([]string, 0, len(set))
	for tag := range set {
		resultList = append(resultList, tag)
	}
	sort.Strings(resultList)
	m.SetList(key, resultList)
	m.SetList(key, maps.Keys(set))
}

func addData(m *Meta, k, v string) {
	if o, ok := m.Get(k); !ok || o == "" {
		m.Set(k, v)
	} else if v != "" {
		m.Set(k, o+" "+v)

	switch key {
	case "", api.KeyID:
		// Empty key and 'id' key will be ignored
		return
	}

	switch Type(key) {
	case TypeString, TypeZettelmarkup:
		if v != "" {
			addData(m, key, v)
		}
	case TypeTagSet:
		addSet(m, key, strings.ToLower(v), func(s string) bool { return s[0] == '#' })
	case TypeWord:
		m.Set(key, strings.ToLower(v))
	case TypeWordSet:
		addSet(m, key, strings.ToLower(v), func(s string) bool { return true })
	case TypeID:

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of zettelstore.
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package meta_test provides tests for the domain specific type 'meta'.

	for i, tc := range td {
		m := parseMetaStr(tc.s)
		if got, ok := m.Get(api.KeyTitle); !ok || got != tc.e {
			t.Log(m)
			t.Errorf("TC=%d: expected %q, got %q", i, tc.e, got)
		}
	}

	m := parseMetaStr(api.KeyTitle + ": ")
	if title, ok := m.Get(api.KeyTitle); ok {
		t.Errorf("Expected a missing title key, but got %q (meta=%v)", title, m)
	}
}

func TestNewFromInput(t *testing.T) {
	t.Parallel()
	testcases := []struct {
		input string
		exp   []meta.Pair
	}{
		{"", []meta.Pair{}},
		{" a:b", []meta.Pair{{"a", "b"}}},
		{"%a:b", []meta.Pair{}},
		{"a:b\r\n\r\nc:d", []meta.Pair{{"a", "b"}}},
		{"a:b\r\n%c:d", []meta.Pair{{"a", "b"}}},
		{"% a:b\r\n c:d", []meta.Pair{{"c", "d"}}},
		{"---\r\na:b\r\n", []meta.Pair{{"a", "b"}}},
		{"---\r\na:b\r\n--\r\nc:d", []meta.Pair{{"a", "b"}, {"c", "d"}}},
		{"---\r\na:b\r\n---\r\nc:d", []meta.Pair{{"a", "b"}}},
		{"---\r\na:b\r\n----\r\nc:d", []meta.Pair{{"a", "b"}}},
		{"new-title:\nnew-url:", []meta.Pair{{"new-title", ""}, {"new-url", ""}}},
	}
	for i, tc := range testcases {
		meta := parseMetaStr(tc.input)
		if got := meta.Pairs(); !equalPairs(tc.exp, got) {
			t.Errorf("TC=%d: expected=%v, got=%v", i, tc.exp, got)
		}
	}

import (
	"strconv"
	"strings"
	"sync"
	"time"

	"zettelstore.de/c/api"
	"zettelstore.de/c/zjson"
)

// DescriptionType is a description of a specific key type.
type DescriptionType struct {
	Name  string
	IsSet bool
}

	t := &DescriptionType{name, isSet}
	registeredTypes[name] = t
	return t
}

// Supported key types.
var (
	TypeCredential   = registerType(zjson.MetaCredential, false)
	TypeEmpty        = registerType(zjson.MetaEmpty, false)
	TypeID           = registerType(zjson.MetaID, false)
	TypeIDSet        = registerType(zjson.MetaIDSet, true)
	TypeNumber       = registerType(zjson.MetaNumber, false)
	TypeString       = registerType(zjson.MetaString, false)
	TypeTagSet       = registerType(zjson.MetaTagSet, true)
	TypeTimestamp    = registerType(zjson.MetaTimestamp, false)
	TypeURL          = registerType(zjson.MetaURL, false)
	TypeWord         = registerType(zjson.MetaWord, false)
	TypeWordSet      = registerType(zjson.MetaWordSet, true)
	TypeZettelmarkup = registerType(zjson.MetaZettelmarkup, false)
	TypeCredential   = registerType(api.MetaCredential, false)
	TypeEmpty        = registerType(api.MetaEmpty, false)
	TypeID           = registerType(api.MetaID, false)
	TypeIDSet        = registerType(api.MetaIDSet, true)
	TypeNumber       = registerType(api.MetaNumber, false)
	TypeString       = registerType(api.MetaString, false)
	TypeTagSet       = registerType(api.MetaTagSet, true)
	TypeTimestamp    = registerType(api.MetaTimestamp, false)
	TypeURL          = registerType(api.MetaURL, false)
	TypeWord         = registerType(api.MetaWord, false)
	TypeWordSet      = registerType(api.MetaWordSet, true)
	TypeZettelmarkup = registerType(api.MetaZettelmarkup, false)
)

// Type returns a type hint for the given key. If no type hint is specified,
// TypeUnknown is returned.
func (*Meta) Type(key string) *DescriptionType {
	return Type(key)
}

	ErrNoWriteMeta    = errors.New("method WriteMeta is not implemented")
	ErrNoWriteContent = errors.New("method WriteContent is not implemented")
	ErrNoWriteBlocks  = errors.New("method WriteBlocks is not implemented")
	ErrNoWriteInlines = errors.New("method WriteInlines is not implemented")
)

// Create builds a new encoder with the given options.
func Create(enc api.EncodingEnum, env *Environment) Encoder {
	if info, ok := registry[enc]; ok {
		return info.Create(env)
func Create(enc api.EncodingEnum) Encoder {
	if create, ok := registry[enc]; ok {
		return create()
	}
	return nil
}

// Info stores some data about an encoder.
// CreateFunc produces a new encoder.
type Info struct {
	Create  func(*Environment) Encoder
type CreateFunc func() Encoder
	Default bool
}


var registry = map[api.EncodingEnum]Info{}
var registry = map[api.EncodingEnum]CreateFunc{}
var defEncoding api.EncodingEnum

// Register the encoder for later retrieval.
func Register(enc api.EncodingEnum, info Info) {
func Register(enc api.EncodingEnum, create CreateFunc) {
	if _, ok := registry[enc]; ok {
		panic(fmt.Sprintf("Encoder %q already registered", enc))
	}
	if info.Default {
		if defEncoding != api.EncoderUnknown && defEncoding != enc {
			panic(fmt.Sprintf("Default encoder already set: %q, new encoding: %q", defEncoding, enc))
		}
		defEncoding = enc
	}
	registry[enc] = info
	registry[enc] = create
}

// GetEncodings returns all registered encodings, ordered by encoding value.
func GetEncodings() []api.EncodingEnum {
	result := make([]api.EncodingEnum, 0, len(registry))
	for enc := range registry {
		result = append(result, enc)
	}
	return result
}

// GetDefaultEncoding returns the encoding that should be used as default.
func GetDefaultEncoding() api.EncodingEnum {
	if defEncoding != api.EncoderUnknown {
		return defEncoding
	}
	if _, ok := registry[api.EncoderZJSON]; ok {
		return api.EncoderZJSON
	}
	panic("No default encoding given")
	panic("No ZJSON encoding registered")
}

			0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0x00, 0x00, 0x00, 0x0d, 0x49, 0x48, 0x44, 0x52,
			0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x08, 0x00, 0x00, 0x00, 0x00, 0x3a, 0x7e, 0x9b,
			0x55, 0x00, 0x00, 0x00, 0x0a, 0x49, 0x44, 0x41, 0x54, 0x78, 0x9c, 0x63, 0x62, 0x00, 0x00, 0x00,
			0x06, 0x00, 0x03, 0x36, 0x37, 0x7c, 0xa8, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4e, 0x44, 0xae,
			0x42, 0x60, 0x82,
		},
		expect: expectMap{
			encoderZJSON:  `[{"":"BLOB","q":"PNG","s":"png","o":"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABgADNjd8qAAAAABJRU5ErkJggg=="}]`,
			encoderHTML:   `<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABgADNjd8qAAAAABJRU5ErkJggg==" title="PNG">`,
			encoderNative: `[BLOB "PNG" "png" "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABgADNjd8qAAAAABJRU5ErkJggg=="]`,
			encoderText:   "",
			encoderZmk:    `%% Unable to display BLOB with title 'PNG' and syntax 'png'.`,
			encoderZJSON: `[{"":"BLOB","q":"PNG","s":"png","o":"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABgADNjd8qAAAAABJRU5ErkJggg=="}]`,
			encoderHTML:  `<p><img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABgADNjd8qAAAAABJRU5ErkJggg==" title="PNG"></p>`,
			encoderSexpr: `((BLOB "PNG" "png" "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABgADNjd8qAAAAABJRU5ErkJggg=="))`,
			encoderText:  "",
			encoderZmk:   `%% Unable to display BLOB with title 'PNG' and syntax 'png'.`,
		},
	},
}

func TestBlob(t *testing.T) {
	m := meta.New(id.Invalid)
	m.Set(api.KeyTitle, "PNG")
	for testNum, tc := range pngTestCases {
		inp := input.NewInput(tc.blob)
		pe := &peBlocks{bs: parser.ParseBlocks(inp, m, "png")}
		checkEncodings(t, testNum, pe, tc.descr, tc.expect, "???")
	}
}

package encoder_test

var tcsBlock = []zmkTestCase{
	{
		descr: "Empty Zettelmarkup should produce near nothing",
		zmk:   "",
		expect: expectMap{
			encoderZJSON:  `[]`,
			encoderHTML:   "",
			encoderNative: ``,
			encoderText:   "",
			encoderZmk:    useZmk,
			encoderZJSON: `[]`,
			encoderHTML:  "",
			encoderSexpr: `()`,
			encoderText:  "",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple text: Hello, world",
		zmk:   "Hello, world",
		expect: expectMap{
			encoderZJSON:  `[{"":"Para","i":[{"":"Text","s":"Hello,"},{"":"Space"},{"":"Text","s":"world"}]}]`,
			encoderHTML:   "<p>Hello, world</p>",
			encoderNative: `[Para Text "Hello,",Space,Text "world"]`,
			encoderText:   "Hello, world",
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Para","i":[{"":"Text","s":"Hello,"},{"":"Space"},{"":"Text","s":"world"}]}]`,
			encoderHTML:  "<p>Hello, world</p>",
			encoderSexpr: `((PARA (TEXT "Hello,") (SPACE) (TEXT "world")))`,
			encoderText:  "Hello, world",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple block comment",
		zmk:   "%%%\nNo\nrender\n%%%",
		expect: expectMap{
			encoderZJSON:  `[{"":"CommentBlock","s":"No\nrender"}]`,
			encoderHTML:   ``,
			encoderNative: `[CommentBlock "No\nrender"]`,
			encoderText:   ``,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"CommentBlock","s":"No\nrender"}]`,
			encoderHTML:  ``,
			encoderSexpr: `((VERBATIM-COMMENT () "No\nrender"))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Rendered block comment",
		zmk:   "%%%{-}\nRender\n%%%",
		expect: expectMap{
			encoderZJSON:  `[{"":"CommentBlock","a":{"-":""},"s":"Render"}]`,
			encoderHTML:   "<!--\nRender\n-->",
			encoderNative: `[CommentBlock ("",[-]) "Render"]`,
			encoderText:   ``,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"CommentBlock","a":{"-":""},"s":"Render"}]`,
			encoderHTML:  "<!--\nRender\n-->",
			encoderSexpr: `((VERBATIM-COMMENT (("-" "")) "Render"))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Heading",
		zmk:   `=== Top`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Heading","n":1,"s":"top","i":[{"":"Text","s":"Top"}]}]`,
			encoderHTML:   "<h2 id=\"top\">Top</h2>",
			encoderNative: `[Heading 1 #top Text "Top"]`,
			encoderText:   `Top`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Heading","n":1,"s":"top","i":[{"":"Text","s":"Top"}]}]`,
			encoderHTML:  "<h2 id=\"top\">Top</h2>",
			encoderSexpr: `((HEADING 1 () "top" "top" (TEXT "Top")))`,
			encoderText:  `Top`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Einfache Liste",
		descr: "Simple List",
		zmk:   "* A\n* B\n* C",
		expect: expectMap{
			encoderZJSON: `[{"":"Bullet","c":[[{"":"Para","i":[{"":"Text","s":"A"}]}],[{"":"Para","i":[{"":"Text","s":"B"}]}],[{"":"Para","i":[{"":"Text","s":"C"}]}]]}]`,
			encoderHTML:  "<ul>\n<li>A</li>\n<li>B</li>\n<li>C</li>\n</ul>",
			encoderNative: `[BulletList
			encoderHTML:  "<ul><li>A</li><li>B</li><li>C</li></ul>",
			encoderSexpr: `((UNORDERED ((TEXT "A")) ((TEXT "B")) ((TEXT "C"))))`,
 [[Para Text "A"]],
 [[Para Text "B"]],
 [[Para Text "C"]]]`,
			encoderText: "A\nB\nC",
			encoderZmk:  useZmk,
			encoderText:  "A\nB\nC",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Schachtelliste",
		zmk:   "* T1\n** T2\n* T3\n** T4\n* T5",
		descr: "Nested List",
		zmk:   "* T1\n** T2\n* T3\n** T4\n** T5\n* T6",
		expect: expectMap{
			encoderZJSON: `[{"":"Bullet","c":[[{"":"Para","i":[{"":"Text","s":"T1"}]},{"":"Bullet","c":[[{"":"Para","i":[{"":"Text","s":"T2"}]}]]}],[{"":"Para","i":[{"":"Text","s":"T3"}]},{"":"Bullet","c":[[{"":"Para","i":[{"":"Text","s":"T4"}]}]]}],[{"":"Para","i":[{"":"Text","s":"T5"}]}]]}]`,
			encoderHTML: `<ul>
			encoderZJSON: `[{"":"Bullet","c":[[{"":"Para","i":[{"":"Text","s":"T1"}]},{"":"Bullet","c":[[{"":"Para","i":[{"":"Text","s":"T2"}]}]]}],[{"":"Para","i":[{"":"Text","s":"T3"}]},{"":"Bullet","c":[[{"":"Para","i":[{"":"Text","s":"T4"}]}],[{"":"Para","i":[{"":"Text","s":"T5"}]}]]}],[{"":"Para","i":[{"":"Text","s":"T6"}]}]]}]`,
			encoderHTML:  `<ul><li><p>T1</p><ul><li>T2</li></ul></li><li><p>T3</p><ul><li>T4</li><li>T5</li></ul></li><li><p>T6</p></li></ul>`,
<li>
<p>T1</p>
<ul>
<li>T2</li>
</ul>
</li>
<li>
<p>T3</p>
<ul>
<li>T4</li>
</ul>
</li>
<li>
<p>T5</p>
</li>
</ul>`,
			encoderNative: `[BulletList
 [[Para Text "T1"],
  [BulletList
   [[Para Text "T2"]]]],
 [[Para Text "T3"],
  [BulletList
   [[Para Text "T4"]]]],
 [[Para Text "T5"]]]`,
			encoderText: "T1\nT2\nT3\nT4\nT5",
			encoderZmk:  useZmk,
			encoderSexpr: `((UNORDERED ((PARA (TEXT "T1")) (UNORDERED ((TEXT "T2")))) ((PARA (TEXT "T3")) (UNORDERED ((TEXT "T4")) ((TEXT "T5")))) ((PARA (TEXT "T6")))))`,
			encoderText:  "T1\nT2\nT3\nT4\nT5\nT6",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Zwei Listen hintereinander",
		descr: "Sequence of two lists",
		zmk:   "* Item1.1\n* Item1.2\n* Item1.3\n\n* Item2.1\n* Item2.2",
		expect: expectMap{
			encoderZJSON: `[{"":"Bullet","c":[[{"":"Para","i":[{"":"Text","s":"Item1.1"}]}],[{"":"Para","i":[{"":"Text","s":"Item1.2"}]}],[{"":"Para","i":[{"":"Text","s":"Item1.3"}]}],[{"":"Para","i":[{"":"Text","s":"Item2.1"}]}],[{"":"Para","i":[{"":"Text","s":"Item2.2"}]}]]}]`,
			encoderHTML:  "<ul>\n<li>Item1.1</li>\n<li>Item1.2</li>\n<li>Item1.3</li>\n<li>Item2.1</li>\n<li>Item2.2</li>\n</ul>",
			encoderHTML:  "<ul><li>Item1.1</li><li>Item1.2</li><li>Item1.3</li><li>Item2.1</li><li>Item2.2</li></ul>",
			encoderNative: `[BulletList
 [[Para Text "Item1.1"]],
			encoderSexpr: `((UNORDERED ((TEXT "Item1.1")) ((TEXT "Item1.2")) ((TEXT "Item1.3")) ((TEXT "Item2.1")) ((TEXT "Item2.2"))))`,
 [[Para Text "Item1.2"]],
 [[Para Text "Item1.3"]],
 [[Para Text "Item2.1"]],
 [[Para Text "Item2.2"]]]`,
			encoderText: "Item1.1\nItem1.2\nItem1.3\nItem2.1\nItem2.2",
			encoderZmk:  "* Item1.1\n* Item1.2\n* Item1.3\n* Item2.1\n* Item2.2",
			encoderText:  "Item1.1\nItem1.2\nItem1.3\nItem2.1\nItem2.2",
			encoderZmk:   "* Item1.1\n* Item1.2\n* Item1.3\n* Item2.1\n* Item2.2",
		},
	},
	{
		descr: "Simple horizontal rule",
		zmk:   `---`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Thematic"}]`,
			encoderHTML:   "<hr>",
			encoderNative: `[Hrule]`,
			encoderText:   ``,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Thematic"}]`,
			encoderHTML:  "<hr>",
			encoderSexpr: `((THEMATIC ()))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "No list after paragraph",
		zmk:   "Text\n*abc",
		expect: expectMap{
			encoderZJSON:  `[{"":"Para","i":[{"":"Text","s":"Text"},{"":"Soft"},{"":"Text","s":"*abc"}]}]`,
			encoderHTML:   "<p>Text\n*abc</p>",
			encoderNative: `[Para Text "Text",Space,Text "*abc"]`,
			encoderText:   `Text *abc`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Para","i":[{"":"Text","s":"Text"},{"":"Soft"},{"":"Text","s":"*abc"}]}]`,
			encoderHTML:  "<p>Text *abc</p>",
			encoderSexpr: `((PARA (TEXT "Text") (SOFT) (TEXT "*abc")))`,
			encoderText:  `Text *abc`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "A list after paragraph",
		zmk:   "Text\n# abc",
		expect: expectMap{
			encoderZJSON: `[{"":"Para","i":[{"":"Text","s":"Text"}]},{"":"Ordered","c":[[{"":"Para","i":[{"":"Text","s":"abc"}]}]]}]`,
			encoderHTML:  "<p>Text</p>\n<ol>\n<li>abc</li>\n</ol>",
			encoderNative: `[Para Text "Text"],
			encoderHTML:  "<p>Text</p><ol><li>abc</li></ol>",
			encoderSexpr: `((PARA (TEXT "Text")) (ORDERED ((TEXT "abc"))))`,
[OrderedList
 [[Para Text "abc"]]]`,
			encoderText: "Text\nabc",
			encoderZmk:  useZmk,
			encoderText:  "Text\nabc",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Quote Block",
		zmk:   "<<<\nToBeOrNotToBe\n<<< Romeo",
		expect: expectMap{
			encoderZJSON: `[{"":"Excerpt","b":[{"":"Para","i":[{"":"Text","s":"ToBeOrNotToBe"}]}],"i":[{"":"Text","s":"Romeo"}]}]`,
			encoderHTML:  "<blockquote>\n<p>ToBeOrNotToBe</p>\n<cite>Romeo</cite>\n</blockquote>",
			encoderHTML:  "<blockquote><p>ToBeOrNotToBe</p><cite>Romeo</cite></blockquote>",
			encoderNative: `[QuoteBlock
 [[Para Text "ToBeOrNotToBe"]],
			encoderSexpr: `((REGION-QUOTE () ((PARA (TEXT "ToBeOrNotToBe"))) ((TEXT "Romeo"))))`,
 [Cite Text "Romeo"]]`,
			encoderText: "ToBeOrNotToBe\nRomeo",
			encoderZmk:  useZmk,
			encoderText:  "ToBeOrNotToBe\nRomeo",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Quote Block with multiple paragraphs",
		zmk:   "<<<\nToBeOr\n\nNotToBe\n<<< Romeo",
		expect: expectMap{
			encoderZJSON: `[{"":"Excerpt","b":[{"":"Para","i":[{"":"Text","s":"ToBeOr"}]},{"":"Para","i":[{"":"Text","s":"NotToBe"}]}],"i":[{"":"Text","s":"Romeo"}]}]`,
			encoderHTML:  "<blockquote>\n<p>ToBeOr</p>\n<p>NotToBe</p>\n<cite>Romeo</cite>\n</blockquote>",
			encoderHTML:  "<blockquote><p>ToBeOr</p><p>NotToBe</p><cite>Romeo</cite></blockquote>",
			encoderNative: `[QuoteBlock
 [[Para Text "ToBeOr"],
			encoderSexpr: `((REGION-QUOTE () ((PARA (TEXT "ToBeOr")) (PARA (TEXT "NotToBe"))) ((TEXT "Romeo"))))`,
  [Para Text "NotToBe"]],
 [Cite Text "Romeo"]]`,
			encoderText: "ToBeOr\nNotToBe\nRomeo",
			encoderZmk:  useZmk,
			encoderText:  "ToBeOr\nNotToBe\nRomeo",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Verse block",
		zmk: `"""
A line
  another line
Back

Paragraph

    Spacy  Para
""" Author`,
		expect: expectMap{
			encoderZJSON:  "[{\"\":\"Poem\",\"b\":[{\"\":\"Para\",\"i\":[{\"\":\"Text\",\"s\":\"A\"},{\"\":\"Space\",\"s\":\"\u00a0\"},{\"\":\"Text\",\"s\":\"line\"},{\"\":\"Hard\"},{\"\":\"Space\",\"s\":\"\u00a0\u00a0\"},{\"\":\"Text\",\"s\":\"another\"},{\"\":\"Space\",\"s\":\"\u00a0\"},{\"\":\"Text\",\"s\":\"line\"},{\"\":\"Hard\"},{\"\":\"Text\",\"s\":\"Back\"}]},{\"\":\"Para\",\"i\":[{\"\":\"Text\",\"s\":\"Paragraph\"}]},{\"\":\"Para\",\"i\":[{\"\":\"Space\",\"s\":\"\u00a0\u00a0\u00a0\u00a0\"},{\"\":\"Text\",\"s\":\"Spacy\"},{\"\":\"Space\",\"s\":\"\u00a0\u00a0\"},{\"\":\"Text\",\"s\":\"Para\"}]}],\"i\":[{\"\":\"Text\",\"s\":\"Author\"}]}]",
			encoderHTML:   "<div>\n<p>A\u00a0line<br>\n\u00a0\u00a0another\u00a0line<br>\nBack</p>\n<p>Paragraph</p>\n<p>\u00a0\u00a0\u00a0\u00a0Spacy\u00a0\u00a0Para</p>\n<cite>Author</cite>\n</div>",
			encoderNative: "[VerseBlock\n [[Para Text \"A\",Space,Text \"line\",Break,Space 2,Text \"another\",Space,Text \"line\",Break,Text \"Back\"],\n  [Para Text \"Paragraph\"],\n  [Para Space 4,Text \"Spacy\",Space 2,Text \"Para\"]],\n [Cite Text \"Author\"]]",
			encoderText:   "A line\n another line\nBack\nParagraph\n Spacy Para\nAuthor",
			encoderZmk:    "\"\"\"\nA\u00a0line\\\n\u00a0\u00a0another\u00a0line\\\nBack\nParagraph\n\u00a0\u00a0\u00a0\u00a0Spacy\u00a0\u00a0Para\n\"\"\" Author",
			encoderZJSON: "[{\"\":\"Poem\",\"b\":[{\"\":\"Para\",\"i\":[{\"\":\"Text\",\"s\":\"A\"},{\"\":\"Space\",\"s\":\"\u00a0\"},{\"\":\"Text\",\"s\":\"line\"},{\"\":\"Hard\"},{\"\":\"Space\",\"s\":\"\u00a0\u00a0\"},{\"\":\"Text\",\"s\":\"another\"},{\"\":\"Space\",\"s\":\"\u00a0\"},{\"\":\"Text\",\"s\":\"line\"},{\"\":\"Hard\"},{\"\":\"Text\",\"s\":\"Back\"}]},{\"\":\"Para\",\"i\":[{\"\":\"Text\",\"s\":\"Paragraph\"}]},{\"\":\"Para\",\"i\":[{\"\":\"Space\",\"s\":\"\u00a0\u00a0\u00a0\u00a0\"},{\"\":\"Text\",\"s\":\"Spacy\"},{\"\":\"Space\",\"s\":\"\u00a0\u00a0\"},{\"\":\"Text\",\"s\":\"Para\"}]}],\"i\":[{\"\":\"Text\",\"s\":\"Author\"}]}]",
			encoderHTML:  "<div><p>A\u00a0line<br>\u00a0\u00a0another\u00a0line<br>Back</p><p>Paragraph</p><p>\u00a0\u00a0\u00a0\u00a0Spacy\u00a0\u00a0Para</p><cite>Author</cite></div>",
			encoderSexpr: "((REGION-VERSE () ((PARA (TEXT \"A\") (SPACE \"\u00a0\") (TEXT \"line\") (HARD) (SPACE \"\u00a0\u00a0\") (TEXT \"another\") (SPACE \"\u00a0\") (TEXT \"line\") (HARD) (TEXT \"Back\")) (PARA (TEXT \"Paragraph\")) (PARA (SPACE \"\u00a0\u00a0\u00a0\u00a0\") (TEXT \"Spacy\") (SPACE \"\u00a0\u00a0\") (TEXT \"Para\"))) ((TEXT \"Author\"))))",
			encoderText:  "A line\n another line\nBack\nParagraph\n Spacy Para\nAuthor",
			encoderZmk:   "\"\"\"\nA\u00a0line\\\n\u00a0\u00a0another\u00a0line\\\nBack\nParagraph\n\u00a0\u00a0\u00a0\u00a0Spacy\u00a0\u00a0Para\n\"\"\" Author",
		},
	},
	{
		descr: "Span Block",
		zmk: `:::
A simple
   span
and much more
:::`,
		expect: expectMap{
			encoderZJSON: `[{"":"Block","b":[{"":"Para","i":[{"":"Text","s":"A"},{"":"Space"},{"":"Text","s":"simple"},{"":"Soft"},{"":"Space"},{"":"Text","s":"span"},{"":"Soft"},{"":"Text","s":"and"},{"":"Space"},{"":"Text","s":"much"},{"":"Space"},{"":"Text","s":"more"}]}]}]`,
			encoderHTML:  "<div>\n<p>A simple\n span\nand much more</p>\n</div>",
			encoderNative: `[SpanBlock
			encoderHTML:  "<div><p>A simple  span and much more</p></div>",
			encoderSexpr: `((REGION-BLOCK () ((PARA (TEXT "A") (SPACE) (TEXT "simple") (SOFT) (SPACE) (TEXT "span") (SOFT) (TEXT "and") (SPACE) (TEXT "much") (SPACE) (TEXT "more"))) ()))`,
 [[Para Text "A",Space,Text "simple",Space,Space 3,Text "span",Space,Text "and",Space,Text "much",Space,Text "more"]]]`,
			encoderText: `A simple  span and much more`,
			encoderZmk:  useZmk,
			encoderText:  `A simple  span and much more`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Verbatim",
		descr: "Simple Verbatim Code",
		zmk:   "```\nHello\nWorld\n```",
		expect: expectMap{
			encoderZJSON:  `[{"":"CodeBlock","s":"Hello\nWorld"}]`,
			encoderHTML:   "<pre><code>Hello\nWorld</code></pre>",
			encoderNative: `[CodeBlock "Hello\nWorld"]`,
			encoderText:   "Hello\nWorld",
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"CodeBlock","s":"Hello\nWorld"}]`,
			encoderHTML:  "<pre><code>Hello\nWorld</code></pre>",
			encoderSexpr: `((VERBATIM-CODE () "Hello\nWorld"))`,
			encoderText:  "Hello\nWorld",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Verbatim Code with visible spaces",
		zmk:   "```{-}\nHello World\n```",
		expect: expectMap{
			encoderZJSON: `[{"":"CodeBlock","a":{"-":""},"s":"Hello World"}]`,
			encoderHTML:  "<pre><code>Hello\u2423World</code></pre>",
			encoderSexpr: `((VERBATIM-CODE (("-" "")) "Hello World"))`,
			encoderText:  "Hello World",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Verbatim Eval",
		zmk:   "~~~\nHello\nWorld\n~~~",
		expect: expectMap{
			encoderZJSON: `[{"":"EvalBlock","s":"Hello\nWorld"}]`,
			encoderHTML:  "<pre><code class=\"zs-eval\">Hello\nWorld</code></pre>",
			encoderSexpr: `((VERBATIM-EVAL () "Hello\nWorld"))`,
			encoderText:  "Hello\nWorld",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Verbatim Math",
		zmk:   "$$$\nHello\n\\LaTeX\n$$$",
		expect: expectMap{
			encoderZJSON: `[{"":"MathBlock","s":"Hello\n\\LaTeX"}]`,
			encoderHTML:  "<pre><code class=\"zs-math\">Hello\n\\LaTeX</code></pre>",
			encoderSexpr: `((VERBATIM-MATH () "Hello\n\\LaTeX"))`,
			encoderText:  "Hello\n\\LaTeX",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Description List",
		zmk:   "; Zettel\n: Paper\n: Note\n; Zettelkasten\n: Slip box",
		expect: expectMap{
			encoderZJSON: `[{"":"Description","d":[{"i":[{"":"Text","s":"Zettel"}],"e":[[{"":"Para","i":[{"":"Text","s":"Paper"}]}],[{"":"Para","i":[{"":"Text","s":"Note"}]}]]},{"i":[{"":"Text","s":"Zettelkasten"}],"e":[[{"":"Para","i":[{"":"Text","s":"Slip"},{"":"Space"},{"":"Text","s":"box"}]}]]}]}]`,
			encoderHTML:  "<dl>\n<dt>Zettel</dt>\n<dd>Paper</dd>\n<dd>Note</dd>\n<dt>Zettelkasten</dt>\n<dd>Slip box</dd>\n</dl>",
			encoderNative: `[DescriptionList
			encoderHTML:  "<dl><dt>Zettel</dt><dd>Paper</dd><dd>Note</dd><dt>Zettelkasten</dt><dd>Slip box</dd></dl>",
			encoderSexpr: `((DESCRIPTION ((TEXT "Zettel")) (((TEXT "Paper")) ((TEXT "Note"))) ((TEXT "Zettelkasten")) (((TEXT "Slip") (SPACE) (TEXT "box")))))`,
 [Term [Text "Zettel"],
  [Description
   [Para Text "Paper"]],
  [Description
   [Para Text "Note"]]],
 [Term [Text "Zettelkasten"],
  [Description
   [Para Text "Slip",Space,Text "box"]]]]`,
			encoderText: "Zettel\nPaper\nNote\nZettelkasten\nSlip box",
			encoderZmk:  useZmk,
			encoderText:  "Zettel\nPaper\nNote\nZettelkasten\nSlip box",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Table",
		zmk:   "|c1|c2|c3\n|d1||d3",
		expect: expectMap{
			encoderZJSON: `[{"":"Table","p":[[],[[{"i":[{"":"Text","s":"c1"}]},{"i":[{"":"Text","s":"c2"}]},{"i":[{"":"Text","s":"c3"}]}],[{"i":[{"":"Text","s":"d1"}]},{"i":[]},{"i":[{"":"Text","s":"d3"}]}]]]}]`,
			encoderHTML: `<table>
<tbody>
<tr><td>c1</td><td>c2</td><td>c3</td></tr>
			encoderHTML:  `<table><tbody><tr><td>c1</td><td>c2</td><td>c3</td></tr><tr><td>d1</td><td></td><td>d3</td></tr></tbody></table>`,
<tr><td>d1</td><td></td><td>d3</td></tr>
</tbody>
</table>`,
			encoderNative: `[Table
 [Row [Cell Default Text "c1"],[Cell Default Text "c2"],[Cell Default Text "c3"]],
 [Row [Cell Default Text "d1"],[Cell Default],[Cell Default Text "d3"]]]`,
			encoderText: "c1 c2 c3\nd1  d3",
			encoderZmk:  useZmk,
			encoderSexpr: `((TABLE () ((CELL (TEXT "c1")) (CELL (TEXT "c2")) (CELL (TEXT "c3"))) ((CELL (TEXT "d1")) (CELL) (CELL (TEXT "d3")))))`,
			encoderText:  "c1 c2 c3\nd1  d3",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Table with alignment and comment",
		zmk: `|h1>|=h2|h3:|
|%--+---+---+
|<c1|c2|:c3|
|f1|f2|=f3`,
		expect: expectMap{
			encoderZJSON: `[{"":"Table","p":[[{"s":">","i":[{"":"Text","s":"h1"}]},{"i":[{"":"Text","s":"h2"}]},{"s":":","i":[{"":"Text","s":"h3"}]}],[[{"s":"<","i":[{"":"Text","s":"c1"}]},{"i":[{"":"Text","s":"c2"}]},{"s":":","i":[{"":"Text","s":"c3"}]}],[{"s":">","i":[{"":"Text","s":"f1"}]},{"i":[{"":"Text","s":"f2"}]},{"s":":","i":[{"":"Text","s":"=f3"}]}]]]}]`,
			encoderHTML: `<table>
<thead>
<tr><th class="right">h1</th><th>h2</th><th class="center">h3</th></tr>
</thead>
<tbody>
<tr><td class="left">c1</td><td>c2</td><td class="center">c3</td></tr>
			encoderHTML:  `<table><thead><tr><td class="right">h1</td><td>h2</td><td class="center">h3</td></tr></thead><tbody><tr><td class="left">c1</td><td>c2</td><td class="center">c3</td></tr><tr><td class="right">f1</td><td>f2</td><td class="center">=f3</td></tr></tbody></table>`,
<tr><td class="right">f1</td><td>f2</td><td class="center">=f3</td></tr>
</tbody>
</table>`,
			encoderNative: `[Table
 [Header [Cell Right Text "h1"],[Cell Default Text "h2"],[Cell Center Text "h3"]],
 [Row [Cell Left Text "c1"],[Cell Default Text "c2"],[Cell Center Text "c3"]],
 [Row [Cell Right Text "f1"],[Cell Default Text "f2"],[Cell Center Text "=f3"]]]`,
			encoderText: "h1 h2 h3\nc1 c2 c3\nf1 f2 =f3",
			encoderSexpr: `((TABLE ((CELL-RIGHT (TEXT "h1")) (CELL (TEXT "h2")) (CELL-CENTER (TEXT "h3"))) ((CELL-LEFT (TEXT "c1")) (CELL (TEXT "c2")) (CELL-CENTER (TEXT "c3"))) ((CELL-RIGHT (TEXT "f1")) (CELL (TEXT "f2")) (CELL-CENTER (TEXT "=f3")))))`,
			encoderText:  "h1 h2 h3\nc1 c2 c3\nf1 f2 =f3",
			encoderZmk: `|=h1>|=h2|=h3:
|<c1|c2|c3
|f1|f2|=f3`,
		},
	},
	{
		descr: "Simple Endnotes",
		zmk:   `Text[^Footnote]`,
		expect: expectMap{
			encoderZJSON: `[{"":"Para","i":[{"":"Text","s":"Text"},{"":"Footnote","i":[{"":"Text","s":"Footnote"}]}]}]`,
			encoderHTML:  `<p>Text<sup id="fnref:1"><a class="zs-noteref" href="#fn:1" role="doc-noteref">1</a></sup></p><ol class="zs-endnotes"><li class="zs-endnote" id="fn:1" role="doc-endnote" value="1">Footnote <a class="zs-endnote-backref" href="#fnref:1" role="doc-backlink">&#x21a9;&#xfe0e;</a></li></ol>`,
			encoderSexpr: `((PARA (TEXT "Text") (FOOTNOTE () (TEXT "Footnote"))))`,
			encoderText:  "Text Footnote",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "",
		zmk:   ``,
		expect: expectMap{
			encoderZJSON:  `[]`,
			encoderHTML:   ``,
			encoderNative: ``,
			encoderText:   "",
			encoderZmk:    useZmk,
			encoderZJSON: `[]`,
			encoderHTML:  ``,
			encoderSexpr: `()`,
			encoderText:  "",
			encoderZmk:   useZmk,
		},
	},
}

// func TestEncoderBlock(t *testing.T) {
// 	executeTestCases(t, tcsBlock)
// }

package encoder_test

var tcsInline = []zmkTestCase{
	{
		descr: "Empty Zettelmarkup should produce near nothing (inline)",
		zmk:   "",
		expect: expectMap{
			encoderZJSON:  `[]`,
			encoderHTML:   "",
			encoderNative: ``,
			encoderText:   "",
			encoderZmk:    useZmk,
			encoderZJSON: `[]`,
			encoderHTML:  "",
			encoderSexpr: `()`,
			encoderText:  "",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple text: Hello, world (inline)",
		zmk:   `Hello, world`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Text","s":"Hello,"},{"":"Space"},{"":"Text","s":"world"}]`,
			encoderHTML:   "Hello, world",
			encoderNative: `Text "Hello,",Space,Text "world"`,
			encoderText:   "Hello, world",
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Text","s":"Hello,"},{"":"Space"},{"":"Text","s":"world"}]`,
			encoderHTML:  "Hello, world",
			encoderSexpr: `((TEXT "Hello,") (SPACE) (TEXT "world"))`,
			encoderText:  "Hello, world",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Emphasized formatting",
		zmk:   "__emph__",
		expect: expectMap{
			encoderZJSON:  `[{"":"Emph","i":[{"":"Text","s":"emph"}]}]`,
			encoderHTML:   "<em>emph</em>",
			encoderNative: `Emph [Text "emph"]`,
			encoderText:   "emph",
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Emph","i":[{"":"Text","s":"emph"}]}]`,
			encoderHTML:  "<em>emph</em>",
			encoderSexpr: `((FORMAT-EMPH () (TEXT "emph")))`,
			encoderText:  "emph",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Strong formatting",
		zmk:   "**strong**",
		expect: expectMap{
			encoderZJSON:  `[{"":"Strong","i":[{"":"Text","s":"strong"}]}]`,
			encoderHTML:   "<strong>strong</strong>",
			encoderNative: `Strong [Text "strong"]`,
			encoderText:   "strong",
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Strong","i":[{"":"Text","s":"strong"}]}]`,
			encoderHTML:  "<strong>strong</strong>",
			encoderSexpr: `((FORMAT-STRONG () (TEXT "strong")))`,
			encoderText:  "strong",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Insert formatting",
		zmk:   ">>insert>>",
		expect: expectMap{
			encoderZJSON:  `[{"":"Insert","i":[{"":"Text","s":"insert"}]}]`,
			encoderHTML:   "<ins>insert</ins>",
			encoderNative: `Insert [Text "insert"]`,
			encoderText:   "insert",
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Insert","i":[{"":"Text","s":"insert"}]}]`,
			encoderHTML:  "<ins>insert</ins>",
			encoderSexpr: `((FORMAT-INSERT () (TEXT "insert")))`,
			encoderText:  "insert",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Delete formatting",
		zmk:   "~~delete~~",
		expect: expectMap{
			encoderZJSON:  `[{"":"Delete","i":[{"":"Text","s":"delete"}]}]`,
			encoderHTML:   "<del>delete</del>",
			encoderNative: `Delete [Text "delete"]`,
			encoderText:   "delete",
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Delete","i":[{"":"Text","s":"delete"}]}]`,
			encoderHTML:  "<del>delete</del>",
			encoderSexpr: `((FORMAT-DELETE () (TEXT "delete")))`,
			encoderText:  "delete",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Update formatting",
		zmk:   "~~old~~>>new>>",
		expect: expectMap{
			encoderZJSON:  `[{"":"Delete","i":[{"":"Text","s":"old"}]},{"":"Insert","i":[{"":"Text","s":"new"}]}]`,
			encoderHTML:   "<del>old</del><ins>new</ins>",
			encoderNative: `Delete [Text "old"],Insert [Text "new"]`,
			encoderText:   "oldnew",
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Delete","i":[{"":"Text","s":"old"}]},{"":"Insert","i":[{"":"Text","s":"new"}]}]`,
			encoderHTML:  "<del>old</del><ins>new</ins>",
			encoderSexpr: `((FORMAT-DELETE () (TEXT "old")) (FORMAT-INSERT () (TEXT "new")))`,
			encoderText:  "oldnew",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Superscript formatting",
		zmk:   "^^superscript^^",
		expect: expectMap{
			encoderZJSON:  `[{"":"Super","i":[{"":"Text","s":"superscript"}]}]`,
			encoderHTML:   `<sup>superscript</sup>`,
			encoderNative: `Super [Text "superscript"]`,
			encoderText:   `superscript`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Super","i":[{"":"Text","s":"superscript"}]}]`,
			encoderHTML:  `<sup>superscript</sup>`,
			encoderSexpr: `((FORMAT-SUPER () (TEXT "superscript")))`,
			encoderText:  `superscript`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Subscript formatting",
		zmk:   ",,subscript,,",
		expect: expectMap{
			encoderZJSON:  `[{"":"Sub","i":[{"":"Text","s":"subscript"}]}]`,
			encoderHTML:   `<sub>subscript</sub>`,
			encoderNative: `Sub [Text "subscript"]`,
			encoderText:   `subscript`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Sub","i":[{"":"Text","s":"subscript"}]}]`,
			encoderHTML:  `<sub>subscript</sub>`,
			encoderSexpr: `((FORMAT-SUB () (TEXT "subscript")))`,
			encoderText:  `subscript`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Quotes formatting",
		zmk:   `""quotes""`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Quote","i":[{"":"Text","s":"quotes"}]}]`,
			encoderHTML:   "<q>quotes</q>",
			encoderNative: `Quote [Text "quotes"]`,
			encoderText:   `quotes`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Quote","i":[{"":"Text","s":"quotes"}]}]`,
			encoderHTML:  "<q>quotes</q>",
			encoderSexpr: `((FORMAT-QUOTE () (TEXT "quotes")))`,
			encoderText:  `quotes`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Quotes formatting (german)",
		zmk:   `""quotes""{lang=de}`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Quote","a":{"lang":"de"},"i":[{"":"Text","s":"quotes"}]}]`,
			encoderHTML:   `<q lang="de">quotes</q>`,
			encoderNative: `Quote ("",[lang="de"]) [Text "quotes"]`,
			encoderText:   `quotes`,
			encoderZmk:    `""quotes""{lang="de"}`,
			encoderZJSON: `[{"":"Quote","a":{"lang":"de"},"i":[{"":"Text","s":"quotes"}]}]`,
			encoderHTML:  `<q lang="de">quotes</q>`,
			encoderSexpr: `((FORMAT-QUOTE (("lang" "de")) (TEXT "quotes")))`,
			encoderText:  `quotes`,
			encoderZmk:   `""quotes""{lang="de"}`,
		},
	},
	{
		descr: "Span formatting",
		zmk:   `::span::`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Span","i":[{"":"Text","s":"span"}]}]`,
			encoderHTML:   `<span>span</span>`,
			encoderNative: `Span [Text "span"]`,
			encoderText:   `span`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Span","i":[{"":"Text","s":"span"}]}]`,
			encoderHTML:  `<span>span</span>`,
			encoderSexpr: `((FORMAT-SPAN () (TEXT "span")))`,
			encoderText:  `span`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Code formatting",
		zmk:   "``code``",
		expect: expectMap{
			encoderZJSON:  `[{"":"Code","s":"code"}]`,
			encoderHTML:   `<code>code</code>`,
			encoderNative: `Code "code"`,
			encoderText:   `code`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Code","s":"code"}]`,
			encoderHTML:  `<code>code</code>`,
			encoderSexpr: `((LITERAL-CODE () "code"))`,
			encoderText:  `code`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Code formatting with visible space",
		zmk:   "``x y``{-}",
		expect: expectMap{
			encoderZJSON: `[{"":"Code","a":{"-":""},"s":"x y"}]`,
			encoderHTML:  "<code>x\u2423y</code>",
			encoderSexpr: `((LITERAL-CODE (("-" "")) "x y"))`,
			encoderText:  `x y`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "HTML in Code formatting",
		zmk:   "``<script `` abc",
		expect: expectMap{
			encoderZJSON: `[{"":"Code","s":"<script "},{"":"Space"},{"":"Text","s":"abc"}]`,
			encoderHTML:  "<code>&lt;script\u00a0</code> abc",
			encoderSexpr: `((LITERAL-CODE () "<script ") (SPACE) (TEXT "abc"))`,
			encoderText:  `<script  abc`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Input formatting",
		zmk:   `''input''`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Input","s":"input"}]`,
			encoderHTML:   `<kbd>input</kbd>`,
			encoderNative: `Input "input"`,
			encoderText:   `input`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Input","s":"input"}]`,
			encoderHTML:  `<kbd>input</kbd>`,
			encoderSexpr: `((LITERAL-INPUT () "input"))`,
			encoderText:  `input`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Output formatting",
		zmk:   `==output==`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Output","s":"output"}]`,
			encoderHTML:   `<samp>output</samp>`,
			encoderNative: `Output "output"`,
			encoderText:   `output`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Output","s":"output"}]`,
			encoderHTML:  `<samp>output</samp>`,
			encoderSexpr: `((LITERAL-OUTPUT () "output"))`,
			encoderText:  `output`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Math formatting",
		zmk:   `$$\TeX$$`,
		expect: expectMap{
			encoderZJSON: `[{"":"Math","s":"\\TeX"}]`,
			encoderHTML:  `<code class="zs-math">\TeX</code>`,
			encoderSexpr: `((LITERAL-MATH () "\\TeX"))`,
			encoderText:  `\TeX`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Nested Span Quote formatting",
		zmk:   `::""abc""::{lang=fr}`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Span","a":{"lang":"fr"},"i":[{"":"Quote","i":[{"":"Text","s":"abc"}]}]}]`,
			encoderHTML:   `<span lang="fr"><q>abc</q></span>`,
			encoderNative: `Span ("",[lang="fr"]) [Quote [Text "abc"]]`,
			encoderText:   `abc`,
			encoderZmk:    `::""abc""::{lang="fr"}`,
			encoderZJSON: `[{"":"Span","a":{"lang":"fr"},"i":[{"":"Quote","i":[{"":"Text","s":"abc"}]}]}]`,
			encoderHTML:  `<span lang="fr"><q>abc</q></span>`,
			encoderSexpr: `((FORMAT-SPAN (("lang" "fr")) (FORMAT-QUOTE () (TEXT "abc"))))`,
			encoderText:  `abc`,
			encoderZmk:   `::""abc""::{lang="fr"}`,
		},
	},
	{
		descr: "Simple Citation",
		zmk:   `[@Stern18]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Cite","s":"Stern18"}]`,
			encoderHTML:   `Stern18`, // TODO
			encoderNative: `Cite "Stern18"`,
			encoderText:   ``,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Cite","s":"Stern18"}]`,
			encoderHTML:  `<span>Stern18</span>`, // TODO
			encoderSexpr: `((CITE () "Stern18"))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "No comment",
		zmk:   `% comment`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Text","s":"%"},{"":"Space"},{"":"Text","s":"comment"}]`,
			encoderHTML:   `% comment`,
			encoderNative: `Text "%",Space,Text "comment"`,
			encoderText:   `% comment`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Text","s":"%"},{"":"Space"},{"":"Text","s":"comment"}]`,
			encoderHTML:  `% comment`,
			encoderSexpr: `((TEXT "%") (SPACE) (TEXT "comment"))`,
			encoderText:  `% comment`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Line comment (nogen HTML)",
		zmk:   `%% line comment`,
		expect: expectMap{
			encoderZJSON: `[{"":"Comment","s":"line comment"}]`,
			encoderHTML:  ``,
			encoderSexpr: `((LITERAL-COMMENT () "line comment"))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Line comment",
		zmk:   `%% line comment`,
		zmk:   `%%{-} line comment`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Comment","s":"line comment"}]`,
			encoderHTML:   `<!-- line comment -->`,
			encoderNative: `Comment "line comment"`,
			encoderText:   ``,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Comment","a":{"-":""},"s":"line comment"}]`,
			encoderHTML:  `<!-- line comment -->`,
			encoderSexpr: `((LITERAL-COMMENT (("-" "")) "line comment"))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Comment after text",
		zmk:   `Text %% comment`,
		zmk:   `Text %%{-} comment`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Text","s":"Text"},{"":"Comment","s":"comment"}]`,
			encoderHTML:   `Text <!-- comment -->`,
			encoderNative: `Text "Text",Comment "comment"`,
			encoderText:   `Text`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Text","s":"Text"},{"":"Comment","a":{"-":""},"s":"comment"}]`,
			encoderHTML:  `Text<!-- comment -->`,
			encoderSexpr: `((TEXT "Text") (LITERAL-COMMENT (("-" "")) "comment"))`,
			encoderText:  `Text`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Comment after text and with -->",
		zmk:   `Text %%{-} comment --> end`,
		expect: expectMap{
			encoderZJSON: `[{"":"Text","s":"Text"},{"":"Comment","a":{"-":""},"s":"comment --> end"}]`,
			encoderHTML:  `Text<!-- comment --&gt; end -->`,
			encoderSexpr: `((TEXT "Text") (LITERAL-COMMENT (("-" "")) "comment --> end"))`,
			encoderText:  `Text`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple footnote",
		zmk:   `[^footnote]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Footnote","i":[{"":"Text","s":"footnote"}]}]`,
			encoderHTML:   `<sup id="fnref:0"><a href="#fn:0" class="footnote-ref" role="doc-noteref">0</a></sup>`,
			encoderNative: `Footnote [Text "footnote"]`,
			encoderText:   `footnote`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Footnote","i":[{"":"Text","s":"footnote"}]}]`,
			encoderHTML:  `<sup id="fnref:1"><a class="zs-noteref" href="#fn:1" role="doc-noteref">1</a></sup>`,
			encoderSexpr: `((FOOTNOTE () (TEXT "footnote")))`,
			encoderText:  `footnote`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple mark",
		zmk:   `[!mark]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Mark","s":"mark","q":"mark"}]`,
			encoderHTML:   `<a id="mark"></a>`,
			encoderNative: `Mark "mark" #mark`,
			encoderText:   ``,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Mark","s":"mark","q":"mark"}]`,
			encoderHTML:  `<a id="mark"></a>`,
			encoderSexpr: `((MARK "mark" "mark" "mark"))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Mark with text",
		zmk:   `[!mark|with text]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Mark","s":"mark","q":"mark","i":[{"":"Text","s":"with"},{"":"Space"},{"":"Text","s":"text"}]}]`,
			encoderHTML:   `<a id="mark">with text</a>`,
			encoderNative: `Mark "mark" #mark [Text "with",Space,Text "text"]`,
			encoderText:   `with text`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Mark","s":"mark","q":"mark","i":[{"":"Text","s":"with"},{"":"Space"},{"":"Text","s":"text"}]}]`,
			encoderHTML:  `<a id="mark">with text</a>`,
			encoderSexpr: `((MARK "mark" "mark" "mark" (TEXT "with") (SPACE) (TEXT "text")))`,
			encoderText:  `with text`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Dummy Link",
		zmk:   `[[abc]]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Link","q":"external","s":"abc"}]`,
			encoderHTML:   `<a href="abc" class="external">abc</a>`,
			encoderNative: `Link EXTERNAL "abc"`,
			encoderText:   ``,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Link","q":"external","s":"abc"}]`,
			encoderHTML:  `<a class="external" href="abc">abc</a>`,
			encoderSexpr: `((LINK-EXTERNAL () "abc"))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple URL",
		zmk:   `[[https://zettelstore.de]]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Link","q":"external","s":"https://zettelstore.de"}]`,
			encoderHTML:   `<a href="https://zettelstore.de" class="external">https://zettelstore.de</a>`,
			encoderNative: `Link EXTERNAL "https://zettelstore.de"`,
			encoderText:   ``,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Link","q":"external","s":"https://zettelstore.de"}]`,
			encoderHTML:  `<a class="external" href="https://zettelstore.de">https://zettelstore.de</a>`,
			encoderSexpr: `((LINK-EXTERNAL () "https://zettelstore.de"))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "URL with Text",
		zmk:   `[[Home|https://zettelstore.de]]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Link","q":"external","s":"https://zettelstore.de","i":[{"":"Text","s":"Home"}]}]`,
			encoderHTML:   `<a href="https://zettelstore.de" class="external">Home</a>`,
			encoderNative: `Link EXTERNAL "https://zettelstore.de" [Text "Home"]`,
			encoderText:   `Home`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Link","q":"external","s":"https://zettelstore.de","i":[{"":"Text","s":"Home"}]}]`,
			encoderHTML:  `<a class="external" href="https://zettelstore.de">Home</a>`,
			encoderSexpr: `((LINK-EXTERNAL () "https://zettelstore.de" (TEXT "Home")))`,
			encoderText:  `Home`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Zettel ID",
		zmk:   `[[00000000000100]]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Link","q":"zettel","s":"00000000000100"}]`,
			encoderHTML:   `<a href="00000000000100">00000000000100</a>`,
			encoderNative: `Link ZETTEL "00000000000100"`,
			encoderText:   ``,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Link","q":"zettel","s":"00000000000100"}]`,
			encoderHTML:  `<a href="00000000000100">00000000000100</a>`,
			encoderSexpr: `((LINK-ZETTEL () "00000000000100"))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Zettel ID with Text",
		zmk:   `[[Config|00000000000100]]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Link","q":"zettel","s":"00000000000100","i":[{"":"Text","s":"Config"}]}]`,
			encoderHTML:   `<a href="00000000000100">Config</a>`,
			encoderNative: `Link ZETTEL "00000000000100" [Text "Config"]`,
			encoderText:   `Config`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Link","q":"zettel","s":"00000000000100","i":[{"":"Text","s":"Config"}]}]`,
			encoderHTML:  `<a href="00000000000100">Config</a>`,
			encoderSexpr: `((LINK-ZETTEL () "00000000000100" (TEXT "Config")))`,
			encoderText:  `Config`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Zettel ID with fragment",
		zmk:   `[[00000000000100#frag]]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Link","q":"zettel","s":"00000000000100#frag"}]`,
			encoderHTML:   `<a href="00000000000100#frag">00000000000100#frag</a>`,
			encoderNative: `Link ZETTEL "00000000000100#frag"`,
			encoderText:   ``,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Link","q":"zettel","s":"00000000000100#frag"}]`,
			encoderHTML:  `<a href="00000000000100#frag">00000000000100#frag</a>`,
			encoderSexpr: `((LINK-ZETTEL () "00000000000100#frag"))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Zettel ID with Text and fragment",
		zmk:   `[[Config|00000000000100#frag]]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Link","q":"zettel","s":"00000000000100#frag","i":[{"":"Text","s":"Config"}]}]`,
			encoderHTML:   `<a href="00000000000100#frag">Config</a>`,
			encoderNative: `Link ZETTEL "00000000000100#frag" [Text "Config"]`,
			encoderText:   `Config`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Link","q":"zettel","s":"00000000000100#frag","i":[{"":"Text","s":"Config"}]}]`,
			encoderHTML:  `<a href="00000000000100#frag">Config</a>`,
			encoderSexpr: `((LINK-ZETTEL () "00000000000100#frag" (TEXT "Config")))`,
			encoderText:  `Config`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Fragment link to self",
		zmk:   `[[#frag]]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Link","q":"self","s":"#frag"}]`,
			encoderHTML:   `<a href="#frag">#frag</a>`,
			encoderNative: `Link SELF "#frag"`,
			encoderText:   ``,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Link","q":"self","s":"#frag"}]`,
			encoderHTML:  `<a href="#frag">#frag</a>`,
			encoderSexpr: `((LINK-SELF () "#frag"))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Hosted link",
		zmk:   `[[H|/hosted]]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Link","q":"local","s":"/hosted","i":[{"":"Text","s":"H"}]}]`,
			encoderHTML:   `<a href="/hosted">H</a>`,
			encoderNative: `Link LOCAL "/hosted" [Text "H"]`,
			encoderText:   `H`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Link","q":"local","s":"/hosted","i":[{"":"Text","s":"H"}]}]`,
			encoderHTML:  `<a href="/hosted">H</a>`,
			encoderSexpr: `((LINK-HOSTED () "/hosted" (TEXT "H")))`,
			encoderText:  `H`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Based link",
		zmk:   `[[B|/based]]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Link","q":"local","s":"/based","i":[{"":"Text","s":"B"}]}]`,
			encoderHTML:   `<a href="/based">B</a>`,
			encoderNative: `Link LOCAL "/based" [Text "B"]`,
			encoderText:   `B`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Link","q":"local","s":"/based","i":[{"":"Text","s":"B"}]}]`,
			encoderHTML:  `<a href="/based">B</a>`,
			encoderSexpr: `((LINK-HOSTED () "/based" (TEXT "B")))`,
			encoderText:  `B`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Relative link",
		zmk:   `[[R|../relative]]`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Link","q":"local","s":"../relative","i":[{"":"Text","s":"R"}]}]`,
			encoderHTML:   `<a href="../relative">R</a>`,
			encoderNative: `Link LOCAL "../relative" [Text "R"]`,
			encoderText:   `R`,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Link","q":"local","s":"../relative","i":[{"":"Text","s":"R"}]}]`,
			encoderHTML:  `<a href="../relative">R</a>`,
			encoderSexpr: `((LINK-HOSTED () "../relative" (TEXT "R")))`,
			encoderText:  `R`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Dummy Embed",
		zmk:   `{{abc}}`,
		expect: expectMap{
			encoderZJSON:  `[{"":"Embed","s":"abc"}]`,
			encoderHTML:   `<img src="abc" alt="">`,
			encoderNative: `Embed EXTERNAL "abc"`,
			encoderText:   ``,
			encoderZmk:    useZmk,
			encoderZJSON: `[{"":"Embed","s":"abc"}]`,
			encoderHTML:  `<img src="abc">`,
			encoderSexpr: `((EMBED () (EXTERNAL "abc") ""))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "",
		zmk:   ``,
		expect: expectMap{
			encoderZJSON:  `[]`,
			encoderHTML:   ``,
			encoderNative: ``,
			encoderText:   ``,
			encoderZmk:    useZmk,
			encoderZJSON: `[]`,
			encoderHTML:  ``,
			encoderSexpr: `()`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
}

package encoder_test

import (
	"bytes"
	"fmt"
	"testing"

	"codeberg.org/t73fde/sxpf"
	"zettelstore.de/c/api"
	"zettelstore.de/c/sexpr"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/encoder"
	"zettelstore.de/z/input"
	"zettelstore.de/z/parser"

	_ "zettelstore.de/z/encoder/htmlenc"   // Allow to use HTML encoder.
	_ "zettelstore.de/z/encoder/nativeenc" // Allow to use native encoder.
	_ "zettelstore.de/z/encoder/textenc"   // Allow to use text encoder.
	_ "zettelstore.de/z/encoder/zjsonenc"  // Allow to use ZJSON encoder.
	_ "zettelstore.de/z/encoder/zmkenc"    // Allow to use zmk encoder.
	_ "zettelstore.de/z/encoder/htmlenc"  // Allow to use HTML encoder.
	_ "zettelstore.de/z/encoder/sexprenc" // Allow to use sexpr encoder.
	_ "zettelstore.de/z/encoder/textenc"  // Allow to use text encoder.
	_ "zettelstore.de/z/encoder/zjsonenc" // Allow to use ZJSON encoder.
	_ "zettelstore.de/z/encoder/zmkenc"   // Allow to use zmk encoder.
	"zettelstore.de/z/parser/cleaner"
	_ "zettelstore.de/z/parser/zettelmark" // Allow to use zettelmark parser.
)

type zmkTestCase struct {
	descr  string
	zmk    string
	inline bool
	expect expectMap
}

type expectMap map[api.EncodingEnum]string

const useZmk = "\000"

const (
	encoderZJSON  = api.EncoderZJSON
	encoderHTML   = api.EncoderHTML
	encoderNative = api.EncoderNative
	encoderText   = api.EncoderText
	encoderZmk    = api.EncoderZmk
	encoderZJSON = api.EncoderZJSON
	encoderHTML  = api.EncoderHTML
	encoderSexpr = api.EncoderSexpr
	encoderText  = api.EncoderText
	encoderZmk   = api.EncoderZmk
)

func TestEncoder(t *testing.T) {
	for i := range tcsInline {
		tcsInline[i].inline = true
	}
	executeTestCases(t, append(tcsBlock, tcsInline...))
}

func executeTestCases(t *testing.T, testCases []zmkTestCase) {
	t.Helper()
	for testNum, tc := range testCases {
		inp := input.NewInput([]byte(tc.zmk))
		var pe parserEncoder
		if tc.inline {
			is := parser.ParseInlines(inp, api.ValueSyntaxZmk)
			cleaner.CleanInlineSlice(&is)
			pe = &peInlines{is: is}
		} else {
			pe = &peBlocks{bs: parser.ParseBlocks(inp, nil, api.ValueSyntaxZmk)}
		}
		checkEncodings(t, testNum, pe, tc.descr, tc.expect, tc.zmk)
		checkSexpr(t, testNum, pe, tc.descr)
	}
}

func checkEncodings(t *testing.T, testNum int, pe parserEncoder, descr string, expected expectMap, zmkDefault string) {
	t.Helper()
	for enc, exp := range expected {
		encdr := encoder.Create(enc, nil)
		encdr := encoder.Create(enc)
		got, err := pe.encode(encdr)
		if err != nil {
			t.Error(err)
			t.Error("pe.encode:", err)
			continue
		}
		if enc == api.EncoderZmk && exp == "\000" {
		if enc == api.EncoderZmk && exp == useZmk {
			exp = zmkDefault
		}
		if got != exp {
			prefix := fmt.Sprintf("Test #%d", testNum)
			if d := descr; d != "" {
				prefix += "\nReason:   " + d
			}
			prefix += "\nMode:     " + pe.mode()
			t.Errorf("%s\nEncoder:  %s\nExpected: %q\nGot:      %q", prefix, enc, exp, got)
		}
	}
}

func checkSexpr(t *testing.T, testNum int, pe parserEncoder, descr string) {
	t.Helper()
	encdr := encoder.Create(encoderSexpr)
	exp, err := pe.encode(encdr)
	if err != nil {
		t.Error(err)
		return
	}
	val, err := sxpf.ParseString(sexpr.Smk, exp)
	if err != nil {
		t.Error(err)
		return
	}
	got, err := sxpf.Repr(val)
	if err != nil {
		t.Error(err)
		return
	}
	if exp != got {
		prefix := fmt.Sprintf("Test #%d", testNum)
		if d := descr; d != "" {
			prefix += "\nReason:   " + d
		}
		prefix += "\nMode:     " + pe.mode()
		t.Errorf("%s\n\nExpected: %q\nGot:      %q", prefix, exp, got)
	}
}

type parserEncoder interface {
	encode(encoder.Encoder) (string, error)
	mode() string
}

type peInlines struct {

//-----------------------------------------------------------------------------
// Copyright (c) 2021-2022 Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

package encoder

import (
	"zettelstore.de/z/ast"
	"zettelstore.de/z/strfun"
)

// Environment specifies all data and functions that affects encoding.
type Environment struct {
	// Important for HTML encoder
	Lang           string // default language
	Interactive    bool   // Encoded data will be placed in interactive content
	Xhtml          bool   // use XHTML syntax instead of HTML syntax
	MarkerExternal string // Marker after link to (external) material.
	NewWindow      bool   // open link in new window
	IgnoreMeta     strfun.Set
	footnotes      []footnoteInfo // Stores footnotes detected while encoding
	footnoteNum    int
}

// IsInteractive returns true, if Interactive is enabled and currently embedded
// interactive encoding will take place.
func (env *Environment) IsInteractive(inInteractive bool) bool {
	return inInteractive && env != nil && env.Interactive
}

// IsXHTML return true, if XHTML is enabled.
func (env *Environment) IsXHTML() bool {
	return env != nil && env.Xhtml
}

// HasNewWindow retruns true, if a new browser windows should be opened.
func (env *Environment) HasNewWindow() bool {
	return env != nil && env.NewWindow
}

type footnoteInfo struct {
	fn  *ast.FootnoteNode
	num int
}

// AddFootnote adds a footnote node to the environment and returns the number of that footnote.
func (env *Environment) AddFootnote(fn *ast.FootnoteNode) int {
	if env == nil {
		return 0
	}
	env.footnoteNum++
	env.footnotes = append(env.footnotes, footnoteInfo{fn: fn, num: env.footnoteNum})
	return env.footnoteNum
}

// PopFootnote returns the next footnote and removes it from the list.
func (env *Environment) PopFootnote() (*ast.FootnoteNode, int) {
	if env == nil {
		return nil, -1
	}
	if len(env.footnotes) == 0 {
		env.footnotes = nil
		env.footnoteNum = 0
		return nil, -1
	}
	fni := env.footnotes[0]
	env.footnotes = env.footnotes[1:]
	return fni.fn, fni.num
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package htmlenc encodes the abstract syntax tree into HTML5.
package htmlenc

import (
	"fmt"
	"strconv"
	"strings"

	"zettelstore.de/c/api"
	"zettelstore.de/c/html"
	"zettelstore.de/c/zjson"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/strfun"
)

func (v *visitor) visitVerbatim(vn *ast.VerbatimNode) {
	switch vn.Kind {
	case ast.VerbatimZettel:
		v.b.WriteString("<!--\n")
		v.visitAttributes(vn.Attrs)
		v.writeHTMLEscaped(string(vn.Content))
		v.b.WriteString("\n-->")
	case ast.VerbatimProg:
		oldVisible := v.visibleSpace
		if vn.Attrs != nil {
			v.visibleSpace = vn.Attrs.HasDefault()
		}
		v.b.WriteString("<pre><code")
		v.visitAttributes(vn.Attrs)
		v.b.WriteByte('>')
		v.writeHTMLEscaped(string(vn.Content))
		v.b.WriteString("</code></pre>")
		v.visibleSpace = oldVisible

	case ast.VerbatimComment:
		if vn.Attrs.HasDefault() {
			v.b.WriteString("<!--\n")
			v.writeHTMLEscaped(string(vn.Content))
			v.b.WriteString("\n-->")
		}

	case ast.VerbatimHTML:
		if html.IsSave(string(vn.Content)) {
			v.b.Write(vn.Content)
		}
	default:
		panic(fmt.Sprintf("Unknown verbatim kind %v", vn.Kind))
	}
}

var specialSpanAttr = strfun.NewSet("example", "note", "tip", "important", "caution", "warning")

func processSpanAttributes(attrs zjson.Attributes) zjson.Attributes {
	if attrVal, ok := attrs.Get(""); ok {
		attrVal = strings.ToLower(attrVal)
		if specialSpanAttr.Has(attrVal) {
			attrs = attrs.Clone().Remove("").AddClass("zs-indication").AddClass("zs-" + attrVal)
		}
	}
	return attrs
}

func (v *visitor) visitRegion(rn *ast.RegionNode) {
	var code string
	attrs := rn.Attrs
	oldVerse := v.inVerse
	switch rn.Kind {
	case ast.RegionSpan:
		code = "div"
		attrs = processSpanAttributes(attrs)
	case ast.RegionVerse:
		v.inVerse = true
		code = "div"
	case ast.RegionQuote:
		code = "blockquote"
	default:
		panic(fmt.Sprintf("Unknown region kind %v", rn.Kind))
	}

	v.b.WriteStrings("<", code)
	v.visitAttributes(attrs)
	v.b.WriteString(">\n")
	ast.Walk(v, &rn.Blocks)
	if len(rn.Inlines) > 0 {
		v.b.WriteString("\n<cite>")
		ast.Walk(v, &rn.Inlines)
		v.b.WriteString("</cite>")
	}
	v.b.WriteStrings("\n</", code, ">")
	v.inVerse = oldVerse
}

func (v *visitor) visitHeading(hn *ast.HeadingNode) {
	lvl := hn.Level + 1
	if lvl > 6 {
		lvl = 6 // HTML has H1..H6
	}
	strLvl := strconv.Itoa(lvl)
	v.b.WriteStrings("<h", strLvl)
	v.visitAttributes(hn.Attrs)
	if _, ok := hn.Attrs.Get("id"); !ok {
		if fragment := hn.Fragment; fragment != "" {
			v.b.WriteStrings(" id=\"", fragment, "\"")
		}
	}
	v.b.WriteByte('>')
	ast.Walk(v, &hn.Inlines)
	v.b.WriteStrings("</h", strLvl, ">")
}

var mapNestedListKind = map[ast.NestedListKind]string{
	ast.NestedListOrdered:   "ol",
	ast.NestedListUnordered: "ul",
}

func (v *visitor) visitNestedList(ln *ast.NestedListNode) {
	if ln.Kind == ast.NestedListQuote {
		// NestedListQuote -> HTML <blockquote> doesn't use <li>...</li>
		v.writeQuotationList(ln)
		return
	}

	code, ok := mapNestedListKind[ln.Kind]
	if !ok {
		panic(fmt.Sprintf("Invalid list kind %v", ln.Kind))
	}

	compact := isCompactList(ln.Items)
	v.b.WriteStrings("<", code)
	v.visitAttributes(ln.Attrs)
	v.b.WriteString(">\n")
	for _, item := range ln.Items {
		v.b.WriteString("<li>")
		v.writeItemSliceOrPara(item, compact)
		v.b.WriteString("</li>\n")
	}
	v.b.WriteStrings("</", code, ">")
}

func (v *visitor) writeQuotationList(ln *ast.NestedListNode) {
	v.b.WriteString("<blockquote>\n")
	inPara := false
	for _, item := range ln.Items {
		if pn := getParaItem(item); pn != nil {
			if inPara {
				v.b.WriteByte('\n')
			} else {
				v.b.WriteString("<p>")
				inPara = true
			}
			ast.Walk(v, &pn.Inlines)
		} else {
			if inPara {
				v.writeEndPara()
				inPara = false
			}
			ast.WalkItemSlice(v, item)
		}
	}
	if inPara {
		v.writeEndPara()
	}
	v.b.WriteString("</blockquote>\n")
}

func getParaItem(its ast.ItemSlice) *ast.ParaNode {
	if len(its) != 1 {
		return nil
	}
	if pn, ok := its[0].(*ast.ParaNode); ok {
		return pn
	}
	return nil
}

func isCompactList(insl []ast.ItemSlice) bool {
	for _, ins := range insl {
		if !isCompactSlice(ins) {
			return false
		}
	}
	return true
}

func isCompactSlice(ins ast.ItemSlice) bool {
	if len(ins) < 1 {
		return true
	}
	if len(ins) == 1 {
		switch ins[0].(type) {
		case *ast.ParaNode, *ast.VerbatimNode, *ast.HRuleNode:
			return true
		case *ast.NestedListNode:
			return false
		}
	}
	return false
}

// writeItemSliceOrPara emits the content of a paragraph if the paragraph is
// the only element of the block slice and if compact mode is true. Otherwise,
// the item slice is emitted normally.
func (v *visitor) writeItemSliceOrPara(ins ast.ItemSlice, compact bool) {
	if compact && len(ins) == 1 {
		if para, ok := ins[0].(*ast.ParaNode); ok {
			ast.Walk(v, &para.Inlines)
			return
		}
	}
	for i, in := range ins {
		if i >= 0 {
			v.b.WriteByte('\n')
		}
		ast.Walk(v, in)
	}
	v.b.WriteByte('\n')
}

func (v *visitor) writeDescriptionsSlice(ds ast.DescriptionSlice) {
	if len(ds) == 1 {
		if para, ok := ds[0].(*ast.ParaNode); ok {
			ast.Walk(v, &para.Inlines)
			return
		}
	}
	ast.WalkDescriptionSlice(v, ds)
}

func (v *visitor) visitDescriptionList(dn *ast.DescriptionListNode) {
	v.b.WriteString("<dl>\n")
	for _, descr := range dn.Descriptions {
		v.b.WriteString("<dt>")
		ast.Walk(v, &descr.Term)
		v.b.WriteString("</dt>\n")

		for _, b := range descr.Descriptions {
			v.b.WriteString("<dd>")
			v.writeDescriptionsSlice(b)
			v.b.WriteString("</dd>\n")
		}
	}
	v.b.WriteString("</dl>")
}

func (v *visitor) visitTable(tn *ast.TableNode) {
	v.b.WriteString("<table>\n")
	if len(tn.Header) > 0 {
		v.b.WriteString("<thead>\n")
		v.writeRow(tn.Header, "<th", "</th>")
		v.b.WriteString("</thead>\n")
	}
	if len(tn.Rows) > 0 {
		v.b.WriteString("<tbody>\n")
		for _, row := range tn.Rows {
			v.writeRow(row, "<td", "</td>")
		}
		v.b.WriteString("</tbody>\n")
	}
	v.b.WriteString("</table>")
}

var alignStyle = map[ast.Alignment]string{
	ast.AlignDefault: ">",
	ast.AlignLeft:    " class=\"left\">",
	ast.AlignCenter:  " class=\"center\">",
	ast.AlignRight:   " class=\"right\">",
}

func (v *visitor) writeRow(row ast.TableRow, cellStart, cellEnd string) {
	v.b.WriteString("<tr>")
	for _, cell := range row {
		v.b.WriteString(cellStart)
		if len(cell.Inlines) == 0 {
			v.b.WriteByte('>')
		} else {
			v.b.WriteString(alignStyle[cell.Align])
			ast.Walk(v, &cell.Inlines)
		}
		v.b.WriteString(cellEnd)
	}
	v.b.WriteString("</tr>\n")
}

func (v *visitor) visitBLOB(bn *ast.BLOBNode) {
	switch bn.Syntax {
	case api.ValueSyntaxSVG:
		v.b.Write(bn.Blob)
	case api.ValueSyntaxGif, "jpeg", "png":
		v.b.WriteStrings("<img src=\"data:image/", bn.Syntax, ";base64,")
		v.b.WriteBase64(bn.Blob)
		v.b.WriteString("\" title=\"")
		v.writeQuotedEscaped(bn.Title)
		v.b.WriteString("\">")
	default:
		v.b.WriteStrings("<p class=\"zs-error\">Unable to display BLOB with syntax '", bn.Syntax, "'.</p>")
	}
}

func (v *visitor) writeEndPara() {
	v.b.WriteString("</p>")
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2022 Detlef Stern
// Copyright (c) 2022 Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package htmlenc encodes the abstract syntax tree into HTML5.
// Package htmlenc encodes the abstract syntax tree into HTML5 via zettelstore-client.
package htmlenc

import (
	"io"
	"strings"

	"codeberg.org/t73fde/sxpf"
	"zettelstore.de/c/api"
	"zettelstore.de/c/html"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/encoder"
	"zettelstore.de/z/encoder/sexprenc"
	"zettelstore.de/z/encoder/textenc"
)

func init() {
	encoder.Register(api.EncoderHTML, encoder.Info{
	encoder.Register(api.EncoderHTML, func() encoder.Encoder { return &mySHE })
		Create: func(env *encoder.Environment) encoder.Encoder { return &htmlEncoder{env: env} },
	})
}

type htmlEncoder struct {
	textEnc *textenc.Encoder
}
	env *encoder.Environment

var mySHE = htmlEncoder{
	textEnc: textenc.Create(),
}

// WriteZettel encodes a full zettel as HTML5.
func (he *htmlEncoder) WriteZettel(w io.Writer, zn *ast.ZettelNode, evalMeta encoder.EvalMetaFunc) (int, error) {
	v := newVisitor(he, w)
	if !he.env.IsXHTML() {
		v.b.WriteString("<!DOCTYPE html>\n")
	}
	if env := he.env; env != nil && env.Lang == "" {
		v.b.WriteStrings("<html>\n<head>")
	} else {
		v.b.WriteStrings("<html lang=\"", env.Lang, "\">")
	}
	v.b.WriteString("\n<head>\n<meta charset=\"utf-8\">\n")
	io.WriteString(w, "<html>\n<head>\n<meta charset=\"utf-8\">\n")
	plainTitle, hasTitle := zn.InhMeta.Get(api.KeyTitle)
	if hasTitle {
		v.b.WriteStrings("<title>", v.evalValue(plainTitle, evalMeta), "</title>")
		io.WriteString(w, "<title>")
		is := evalMeta(plainTitle)
		he.textEnc.WriteInlines(w, &is)
		io.WriteString(w, "</title>\n")
	}

	v.acceptMeta(zn.InhMeta, evalMeta)
	v.b.WriteString("\n</head>\n<body>\n")
	acceptMeta(w, he.textEnc, zn.InhMeta, evalMeta)
	io.WriteString(w, "</head>\n<body>\n")
	env := html.NewEncEnvironment(w, 1)
	if hasTitle {
		if isTitle := evalMeta(plainTitle); len(isTitle) > 0 {
			v.b.WriteString("<h1>")
			ast.Walk(v, &isTitle)
			v.b.WriteString("</h1>\n")
			io.WriteString(w, "<h1>")
			if l, err := acceptInlines(env, &isTitle); err != nil {
				return l, err
			}
			io.WriteString(w, "</h1>\n")
		}
	}

	ast.Walk(v, &zn.Ast)
	v.writeEndnotes()
	v.b.WriteString("</body>\n</html>")
	_, err := acceptBlocks(env, &zn.Ast)
	if err == nil {
		// env.WriteEndnotes()
		io.WriteString(w, "</body>\n</html>")
	length, err := v.b.Flush()
	return length, err
	}
	return 0, err
}

// WriteMeta encodes meta data as HTML5.
func (he *htmlEncoder) WriteMeta(w io.Writer, m *meta.Meta, evalMeta encoder.EvalMetaFunc) (int, error) {
	v := newVisitor(he, w)

	// Write title
	if title, ok := m.Get(api.KeyTitle); ok {
		v.b.WriteStrings("<meta name=\"zs-", api.KeyTitle, "\" content=\"")
		v.writeQuotedEscaped(v.evalValue(title, evalMeta))
		v.b.WriteString("\">")
	}

	// Write other metadata
	v.acceptMeta(m, evalMeta)
	acceptMeta(w, he.textEnc, m, evalMeta)
	length, err := v.b.Flush()
	return length, err
	return 0, nil
}

func (he *htmlEncoder) WriteContent(w io.Writer, zn *ast.ZettelNode) (int, error) {
	return he.WriteBlocks(w, &zn.Ast)
}

// WriteBlocks encodes a block slice.
func (he *htmlEncoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {
	v := newVisitor(he, w)
	ast.Walk(v, bs)
	v.writeEndnotes()
	length, err := v.b.Flush()
	return length, err
func (*htmlEncoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {
	env := html.NewEncEnvironment(w, 1)
	_, err := acceptBlocks(env, bs)
	if err == nil {
		env.WriteEndnotes()
		err = env.GetError()
	}
	return 0, err
}

// WriteInlines writes an inline slice to the writer
func (he *htmlEncoder) WriteInlines(w io.Writer, is *ast.InlineSlice) (int, error) {
	v := newVisitor(he, w)
	if env := he.env; env != nil {
		v.inInteractive = env.Interactive
func (*htmlEncoder) WriteInlines(w io.Writer, is *ast.InlineSlice) (int, error) {
	env := html.NewEncEnvironment(w, 1)
	return acceptInlines(env, is)
}

func acceptMeta(w io.Writer, textEnc encoder.Encoder, m *meta.Meta, evalMeta encoder.EvalMetaFunc) {
	for _, p := range m.ComputedPairs() {
		io.WriteString(w, `<meta name="zs-`)
		io.WriteString(w, p.Key)
		io.WriteString(w, `" content="`)
		is := evalMeta(p.Value)
		var sb strings.Builder
		textEnc.WriteInlines(&sb, &is)
		html.AttributeEscape(w, sb.String())
		io.WriteString(w, "\">\n")
	}
}
	ast.Walk(v, is)
	length, err := v.b.Flush()
	return length, err

func acceptBlocks(env *html.EncEnvironment, bs *ast.BlockSlice) (int, error) {
	lst := sexprenc.GetSexpr(bs)
	sxpf.Eval(env, lst)
	return 0, env.GetError()
}
func acceptInlines(env *html.EncEnvironment, is *ast.InlineSlice) (int, error) {
	lst := sexprenc.GetSexpr(is)
	sxpf.Eval(env, lst)
	return 0, env.GetError()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

// Package htmlenc encodes the abstract syntax tree into HTML5.
package htmlenc

import (
	"fmt"
	"strconv"

	"zettelstore.de/c/api"
	"zettelstore.de/c/html"
	"zettelstore.de/c/zjson"
	"zettelstore.de/z/ast"
)

func (v *visitor) visitBreak(bn *ast.BreakNode) {
	if bn.Hard {
		if v.env.IsXHTML() {
			v.b.WriteString("<br />\n")
		} else {
			v.b.WriteString("<br>\n")
		}
	} else {
		v.b.WriteByte('\n')
	}
}

func (v *visitor) visitLink(ln *ast.LinkNode) {
	switch ln.Ref.State {
	case ast.RefStateSelf, ast.RefStateFound, ast.RefStateHosted, ast.RefStateBased:
		v.writeAHref(ln.Ref, ln.Attrs, &ln.Inlines)
	case ast.RefStateBroken:
		attrs := ln.Attrs.Clone()
		attrs = attrs.Set("class", "broken")
		attrs = attrs.Set("title", "Zettel not found") // l10n
		v.writeAHref(ln.Ref, attrs, &ln.Inlines)
	case ast.RefStateExternal:
		attrs := ln.Attrs.Clone()
		attrs = attrs.Set("class", "external")
		if v.env.HasNewWindow() {
			attrs = attrs.Set("target", "_blank").Set("rel", "noopener noreferrer")
		}
		v.writeAHref(ln.Ref, attrs, &ln.Inlines)
		if v.env != nil {
			v.b.WriteString(v.env.MarkerExternal)
		}
	default:
		if v.env.IsInteractive(v.inInteractive) {
			v.writeSpan(&ln.Inlines, ln.Attrs)
			return
		}
		v.b.WriteString("<a href=\"")
		v.writeQuotedEscaped(ln.Ref.Value)
		v.b.WriteByte('"')
		v.visitAttributes(ln.Attrs)
		v.b.WriteByte('>')
		v.writeLinkInlines(&ln.Inlines, ln.Ref)
		v.inInteractive = false
		v.b.WriteString("</a>")
	}
}

func (v *visitor) writeAHref(ref *ast.Reference, attrs zjson.Attributes, is *ast.InlineSlice) {
	if v.env.IsInteractive(v.inInteractive) {
		v.writeSpan(is, attrs)
		return
	}
	v.b.WriteString("<a href=\"")
	v.writeReference(ref)
	v.b.WriteByte('"')
	v.visitAttributes(attrs)
	v.b.WriteByte('>')
	v.writeLinkInlines(is, ref)
	v.b.WriteString("</a>")
}
func (v *visitor) writeLinkInlines(is *ast.InlineSlice, ref *ast.Reference) {
	saveInteractive := v.inInteractive
	v.inInteractive = true
	if len(*is) == 0 {
		v.writeHTMLEscaped(ref.Value)
	} else {
		ast.Walk(v, is)
	}
	v.inInteractive = saveInteractive
}

func (v *visitor) visitEmbedRef(en *ast.EmbedRefNode) {
	v.b.WriteString("<img src=\"")
	v.writeReference(en.Ref)
	v.b.WriteString("\" alt=\"")
	ast.Walk(v, &en.Inlines) // TODO: wrong, must use textenc
	v.b.WriteByte('"')
	v.visitAttributes(en.Attrs)
	if v.env.IsXHTML() {
		v.b.WriteString(" />")
	} else {
		v.b.WriteByte('>')
	}
}

func (v *visitor) visitEmbedBLOB(en *ast.EmbedBLOBNode) {
	if en.Syntax == api.ValueSyntaxSVG {
		v.b.Write(en.Blob)
		return
	}

	v.b.WriteString("<img src=\"data:image/")
	v.b.WriteStrings(en.Syntax, ";base64,")
	v.b.WriteBase64(en.Blob)
	v.b.WriteString("\" alt=\"")
	ast.Walk(v, &en.Inlines)
	v.b.WriteByte('"')
	v.visitAttributes(en.Attrs)
	if v.env.IsXHTML() {
		v.b.WriteString(" />")
	} else {
		v.b.WriteByte('>')
	}
}

func (v *visitor) visitCite(cn *ast.CiteNode) {
	v.b.WriteString(cn.Key)
	if len(cn.Inlines) > 0 {
		v.b.WriteString(", ")
		ast.Walk(v, &cn.Inlines)
	}
}

func (v *visitor) visitFootnote(fn *ast.FootnoteNode) {
	if v.env.IsInteractive(v.inInteractive) {
		return
	}

	n := strconv.Itoa(v.env.AddFootnote(fn))
	v.b.WriteStrings("<sup id=\"fnref:", n, "\"><a href=\"#fn:", n, "\" class=\"footnote-ref\" role=\"doc-noteref\">", n, "</a></sup>")
	// TODO: what to do with Attrs?
}

func (v *visitor) visitMark(mn *ast.MarkNode) {
	if v.env.IsInteractive(v.inInteractive) {
		return
	}
	if fragment := mn.Fragment; fragment != "" {
		v.b.WriteStrings(`<a id="`, fragment, `">`)
		if len(mn.Inlines) > 0 {
			ast.Walk(v, &mn.Inlines)
		}
		v.b.WriteString("</a>")
	}
}

func (v *visitor) visitFormat(fn *ast.FormatNode) {
	var code string
	switch fn.Kind {
	case ast.FormatEmph:
		code = "em"
	case ast.FormatStrong:
		code = "strong"
	case ast.FormatInsert:
		code = "ins"
	case ast.FormatDelete:
		code = "del"
	case ast.FormatSuper:
		code = "sup"
	case ast.FormatSub:
		code = "sub"
	case ast.FormatQuote:
		code = "q"
	case ast.FormatSpan:
		v.writeSpan(&fn.Inlines, processSpanAttributes(fn.Attrs))
		return
	default:
		panic(fmt.Sprintf("Unknown format kind %v", fn.Kind))
	}
	v.b.WriteStrings("<", code)
	v.visitAttributes(fn.Attrs)
	v.b.WriteByte('>')
	ast.Walk(v, &fn.Inlines)
	v.b.WriteStrings("</", code, ">")
}

func (v *visitor) writeSpan(is *ast.InlineSlice, attrs zjson.Attributes) {
	v.b.WriteString("<span")
	v.visitAttributes(attrs)
	v.b.WriteByte('>')
	ast.Walk(v, is)
	v.b.WriteString("</span>")

}

func (v *visitor) visitLiteral(ln *ast.LiteralNode) {
	switch ln.Kind {
	case ast.LiteralProg:
		v.writeLiteral("<code", "</code>", ln.Attrs, ln.Content)
	case ast.LiteralInput:
		v.writeLiteral("<kbd", "</kbd>", ln.Attrs, ln.Content)
	case ast.LiteralOutput:
		v.writeLiteral("<samp", "</samp>", ln.Attrs, ln.Content)
	case ast.LiteralZettel, ast.LiteralComment:
		if v.inlinePos > 0 {
			v.b.WriteByte(' ')
		}
		v.b.WriteString("<!-- ")
		v.writeHTMLEscaped(string(ln.Content)) // writeCommentEscaped
		v.b.WriteString(" -->")
	case ast.LiteralHTML:
		if html.IsSave(string(ln.Content)) {
			v.b.Write(ln.Content)
		}
	default:
		panic(fmt.Sprintf("Unknown literal kind %v", ln.Kind))
	}
}

func (v *visitor) writeLiteral(codeS, codeE string, attrs zjson.Attributes, content []byte) {
	oldVisible := v.visibleSpace
	if attrs != nil {
		v.visibleSpace = attrs.HasDefault()
	}
	v.b.WriteString(codeS)
	v.visitAttributes(attrs)
	v.b.WriteByte('>')
	v.writeHTMLEscaped(string(content))
	v.b.WriteString(codeE)
	v.visibleSpace = oldVisible
}

//-----------------------------------------------------------------------------
// Copyright (c) 2020-2022 Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

package htmlenc

import (
	"bytes"
	"io"
	"strconv"
	"strings"

	"zettelstore.de/c/api"
	"zettelstore.de/c/html"
	"zettelstore.de/c/zjson"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/encoder"
	"zettelstore.de/z/strfun"
)

// visitor writes the abstract syntax tree to an io.Writer.
type visitor struct {
	env           *encoder.Environment
	b             encoder.EncWriter
	visibleSpace  bool // Show space character in plain text
	inVerse       bool // In verse block
	inInteractive bool // Rendered interactive HTML code
	textEnc       encoder.Encoder
	inlinePos     int // Element position in inline list node
}

func newVisitor(he *htmlEncoder, w io.Writer) *visitor {
	return &visitor{
		env:     he.env,
		b:       encoder.NewEncWriter(w),
		textEnc: encoder.Create(api.EncoderText, nil),
	}
}

func (v *visitor) Visit(node ast.Node) ast.Visitor {
	switch n := node.(type) {
	case *ast.BlockSlice:
		for i, bn := range *n {
			if i > 0 {
				v.b.WriteByte('\n')
			}
			ast.Walk(v, bn)
		}
	case *ast.InlineSlice:
		for i, in := range *n {
			v.inlinePos = i
			ast.Walk(v, in)
		}
		v.inlinePos = 0
	case *ast.ParaNode:
		v.b.WriteString("<p>")
		ast.Walk(v, &n.Inlines)
		v.writeEndPara()
	case *ast.VerbatimNode:
		v.visitVerbatim(n)
	case *ast.RegionNode:
		v.visitRegion(n)
	case *ast.HeadingNode:
		v.visitHeading(n)
	case *ast.HRuleNode:
		v.b.WriteString("<hr")
		v.visitAttributes(n.Attrs)
		if v.env.IsXHTML() {
			v.b.WriteString(" />")
		} else {
			v.b.WriteBytes('>')
		}
	case *ast.NestedListNode:
		v.visitNestedList(n)
	case *ast.DescriptionListNode:
		v.visitDescriptionList(n)
	case *ast.TableNode:
		v.visitTable(n)
	case *ast.TranscludeNode:
		return nil // Nothing to write. Or: an iFrame?
	case *ast.BLOBNode:
		v.visitBLOB(n)
	case *ast.TextNode:
		v.writeHTMLEscaped(n.Text)
	case *ast.TagNode:
		v.b.WriteString("<span class=\"zettel-tag\">#")
		v.writeHTMLEscaped(n.Tag)
		v.b.WriteString("</span>")
	case *ast.SpaceNode:
		if v.inVerse || v.env.IsXHTML() {
			v.b.WriteString(n.Lexeme)
		} else {
			v.b.WriteByte(' ')
		}
	case *ast.BreakNode:
		v.visitBreak(n)
	case *ast.LinkNode:
		v.visitLink(n)
	case *ast.EmbedRefNode:
		v.visitEmbedRef(n)
	case *ast.EmbedBLOBNode:
		v.visitEmbedBLOB(n)
	case *ast.CiteNode:
		v.visitCite(n)
	case *ast.FootnoteNode:
		v.visitFootnote(n)
	case *ast.MarkNode:
		v.visitMark(n)
	case *ast.FormatNode:
		v.visitFormat(n)
	case *ast.LiteralNode:
		v.visitLiteral(n)
	default:
		return v
	}
	return nil
}

var mapMetaKey = map[string]string{
	api.KeyCopyright: "copyright",
	api.KeyLicense:   "license",
}

func (v *visitor) acceptMeta(m *meta.Meta, evalMeta encoder.EvalMetaFunc) {
	ignore := v.setupIgnoreSet()
	ignore.Set(api.KeyTitle)
	if tags, ok := m.Get(api.KeyAllTags); ok {
		v.writeTags(tags)
		ignore.Set(api.KeyAllTags)
		ignore.Set(api.KeyTags)
	} else if tags, ok = m.Get(api.KeyTags); ok {
		v.writeTags(tags)
		ignore.Set(api.KeyTags)
	}

	for _, p := range m.ComputedPairs() {
		key := p.Key
		if ignore.Has(key) {
			continue
		}
		value := p.Value
		if m.Type(key) == meta.TypeZettelmarkup {
			if v := v.evalValue(value, evalMeta); v != "" {
				value = v
			}
		}
		if mKey, ok := mapMetaKey[key]; ok {
			v.writeMeta("", mKey, value)
		} else {
			v.writeMeta("zs-", key, value)
		}
	}
}

func (v *visitor) evalValue(value string, evalMeta encoder.EvalMetaFunc) string {
	var buf bytes.Buffer
	is := evalMeta(value)
	_, err := v.textEnc.WriteInlines(&buf, &is)
	if err == nil {
		return buf.String()
	}
	return ""
}

func (v *visitor) setupIgnoreSet() strfun.Set {
	if v.env == nil || v.env.IgnoreMeta == nil {
		return make(strfun.Set)
	}
	result := make(strfun.Set, len(v.env.IgnoreMeta))
	for k := range v.env.IgnoreMeta {
		result.Set(k)
	}
	return result
}

func (v *visitor) writeTags(tags string) {
	v.b.WriteString("\n<meta name=\"keywords\" content=\"")
	for i, val := range meta.ListFromValue(tags) {
		if i > 0 {
			v.b.WriteString(", ")
		}
		v.writeQuotedEscaped(strings.TrimPrefix(val, "#"))
	}
	v.b.WriteString("\">")
}

func (v *visitor) writeMeta(prefix, key, value string) {
	v.b.WriteStrings("\n<meta name=\"", prefix, key, "\" content=\"")
	v.writeQuotedEscaped(value)
	v.b.WriteString("\">")
}

func (v *visitor) writeEndnotes() {
	fn, fnNum := v.env.PopFootnote()
	if fn == nil {
		return
	}
	v.b.WriteString("\n<ol class=\"endnotes\">\n")
	for fn != nil {
		n := strconv.Itoa(fnNum)
		v.b.WriteStrings("<li value=\"", n, "\" id=\"fn:", n, "\" role=\"doc-endnote\">")
		ast.Walk(v, &fn.Inlines)
		v.b.WriteStrings(
			" <a href=\"#fnref:",
			n,
			"\" class=\"footnote-backref\" role=\"doc-backlink\">&#x21a9;&#xfe0e;</a></li>\n")
		fn, fnNum = v.env.PopFootnote()
	}
	v.b.WriteString("</ol>\n")
}

// visitAttributes write HTML attributes
func (v *visitor) visitAttributes(a zjson.Attributes) {
	if a.IsEmpty() {
		return
	}
	a = a.Clone().RemoveDefault()

	for _, k := range a.Keys() {
		if k == "" || k == "-" {
			continue
		}
		v.b.WriteStrings(" ", k)
		vl := a[k]
		if len(vl) > 0 {
			v.b.WriteString("=\"")
			v.writeQuotedEscaped(vl)
			v.b.WriteByte('"')
		}
	}
}

func (v *visitor) writeHTMLEscaped(s string) {
	if v.visibleSpace {
		html.EscapeVisible(&v.b, s)
	} else {
		html.Escape(&v.b, s)
	}
}

func (v *visitor) writeQuotedEscaped(s string) {
	html.AttributeEscape(&v.b, s)
}

func (v *visitor) writeReference(ref *ast.Reference) {
	if ref.URL == nil {
		v.writeHTMLEscaped(ref.Value)
		return
	}
	v.b.WriteString(ref.URL.String())
}