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

0.6.0
0.7.1

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

}

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

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

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

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

import (
	"net/url"
	"strings"

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

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

// ParseReference parses a string and returns a reference.
func ParseReference(s string) *Reference {
	if s == "" || s == "00000000000000" {
		return &Reference{URL: nil, Value: s, State: RefStateInvalid}
	}
	if strings.HasPrefix(s, SearchPrefix) {
		return &Reference{URL: nil, Value: s[len(SearchPrefix):], State: RefStateSearch}
	if strings.HasPrefix(s, QueryPrefix) {
		return &Reference{URL: nil, Value: s[len(QueryPrefix):], State: RefStateQuery}
	}
	if state, ok := localState(s); ok {
		if state == RefStateBased {
			s = s[1:]
		}
		u, err := url.Parse(s)
		if err == nil {

}

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

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

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

import (
	"time"

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

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

}

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

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

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

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

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

		if ur := meta.GetUserRole(val); ur != meta.UserRoleUnknown {
			return ur
		}
	}
	return meta.UserRoleReader
}

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

//-----------------------------------------------------------------------------
// 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 policy

import (
	"context"

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

}

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

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

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

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

	"strconv"
	"time"

	"zettelstore.de/c/api"
	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/search"
	"zettelstore.de/z/query"
)

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

type MetaFunc func(*meta.Meta)

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

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

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

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

// ManagedBoxStats records statistics about the box.
type ManagedBoxStats struct {

type Box interface {
	BaseBox

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

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

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

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

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

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

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

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

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

			}
		}
	}
	cb.log.Trace().Err(box.ErrNotFound).Msg("GetMeta/Err")
	return nil, box.ErrNotFound
}

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

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

import (
	"bytes"

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

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

func genConfigZettelC(*meta.Meta) []byte {
	var buf bytes.Buffer
	for i, p := range myConfig.Pairs() {

import (
	"bytes"
	"fmt"

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

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

func genKeysC(*meta.Meta) []byte {
	keys := meta.GetSortedKeyDescriptions()
	var buf bytes.Buffer

//-----------------------------------------------------------------------------
// 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 compbox

	"zettelstore.de/z/kernel"
)

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

func genLogC(*meta.Meta) []byte {
	const tsFormat = "2006-01-02 15:04:05.999999"
	entries := kernel.Main.RetrieveLogEntries()
	var buf bytes.Buffer

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

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

func genManagerC(*meta.Meta) []byte {
	kvl := kernel.Main.GetServiceStatistics(kernel.BoxService)
	if len(kvl) == 0 {
		return nil

	"fmt"
	"sort"
	"strings"

	"zettelstore.de/c/api"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/parser"
)

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

func genParserC(*meta.Meta) []byte {
	var buf bytes.Buffer
	buf.WriteString("|=Syntax<|=Alt. Value(s):|=Text Parser?:|=Image Format?:\n")

	m.Set(api.KeyTitle, title)
	m.Set(api.KeyVisibility, api.ValueVisibilityExpert)
	return m
}

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

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

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

  h1 { font-size:1.5rem;  margin:.65rem 0 }
  h2 { font-size:1.25rem; margin:.70rem 0 }
  h3 { font-size:1.15rem; margin:.75rem 0 }
  h4 { font-size:1.05rem; margin:.8rem 0; font-weight: bold }
  h5 { font-size:1.05rem; margin:.8rem 0 }
  h6 { font-size:1.05rem; margin:.8rem 0; font-weight: lighter }
  p { margin: .5rem 0 0 0 }
  ol,ul { padding-left: 1.1rem }
  li,figure,figcaption,dl { margin: 0 }
  dt { margin: .5rem 0 0 0 }
  dt+dd { margin-top: 0 }
  dd { margin: .5rem 0 0 2rem }
  dd > p:first-child { margin: 0 0 0 0 }
  blockquote {
    border-left: 0.5rem solid lightgray;

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

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

func init() {
	manager.Register(
		" const",
		func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
			return &constBox{

		cb.log.Trace().Msg("GetMeta")
		return meta.NewWithData(zid, z.header), nil
	}
	cb.log.Trace().Err(box.ErrNotFound).Msg("GetMeta")
	return nil, box.ErrNotFound
}

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

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

var constZettelMap = map[id.Zid]constZettel{
	id.ConfigurationZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Runtime Configuration",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     api.ValueSyntaxNone,
			api.KeyCreated:    "20200804111624",
			api.KeyVisibility: api.ValueVisibilityOwner,
		},
		domain.NewContent(nil)},
	id.MustParse(api.ZidLicense): {
		constHeader{
			api.KeyTitle:      "Zettelstore License",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     api.ValueSyntaxText,
			api.KeyCreated:    "20210504135842",
			api.KeyLang:       api.ValueLangEN,
			api.KeyModified:   "20220131153422",
			api.KeyReadOnly:   api.ValueTrue,
			api.KeyVisibility: api.ValueVisibilityPublic,
		},
		domain.NewContent(contentLicense)},
	id.MustParse(api.ZidAuthors): {
		constHeader{
			api.KeyTitle:      "Zettelstore Contributors",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     api.ValueSyntaxZmk,
			api.KeyCreated:    "20210504135842",
			api.KeyLang:       api.ValueLangEN,
			api.KeyReadOnly:   api.ValueTrue,
			api.KeyVisibility: api.ValueVisibilityLogin,
		},
		domain.NewContent(contentContributors)},
	id.MustParse(api.ZidDependencies): {
		constHeader{
			api.KeyTitle:      "Zettelstore Dependencies",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     api.ValueSyntaxZmk,
			api.KeyLang:       api.ValueLangEN,
			api.KeyReadOnly:   api.ValueTrue,
			api.KeyVisibility: api.ValueVisibilityLogin,
			api.KeyCreated:    "20210504135842",
			api.KeyModified:   "20220824161200",
		},
		domain.NewContent(contentDependencies)},
	id.BaseTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Base HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     syntaxTemplate,
			api.KeyCreated:    "20210504135842",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(contentBaseMustache)},
	id.LoginTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Login Form HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     syntaxTemplate,
			api.KeyCreated:    "20200804111624",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(contentLoginMustache)},
	id.ZettelTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Zettel HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     syntaxTemplate,
			api.KeyCreated:    "20200804111624",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(contentZettelMustache)},
	id.InfoTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Info HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     syntaxTemplate,
			api.KeyCreated:    "20200804111624",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(contentInfoMustache)},
	id.ContextTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Context HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     syntaxTemplate,
			api.KeyCreated:    "20210218181140",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(contentContextMustache)},
	id.FormTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Form HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     syntaxTemplate,
			api.KeyCreated:    "20200804111624",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(contentFormMustache)},
	id.RenameTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Rename Form HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     syntaxTemplate,
			api.KeyCreated:    "20200804111624",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(contentRenameMustache)},
	id.DeleteTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Delete HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     syntaxTemplate,
			api.KeyCreated:    "20200804111624",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(contentDeleteMustache)},
	id.ListTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore List Zettel HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     syntaxTemplate,
			api.KeyCreated:    "20200804111624",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(contentListZettelMustache)},
	id.RolesTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore List Roles HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     syntaxTemplate,
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(contentListRolesMustache)},
	id.TagsTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore List Tags HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     syntaxTemplate,
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(contentListTagsMustache)},
	id.ErrorTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Error HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     syntaxTemplate,
			api.KeyCreated:    "20210305133215",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(contentErrorMustache)},
	id.MustParse(api.ZidBaseCSS): {
		constHeader{
			api.KeyTitle:      "Zettelstore Base CSS",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     "css",
			api.KeyCreated:    "20200804111624",
			api.KeyVisibility: api.ValueVisibilityPublic,
		},
		domain.NewContent(contentBaseCSS)},
	id.MustParse(api.ZidUserCSS): {
		constHeader{
			api.KeyTitle:      "Zettelstore User CSS",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     "css",
			api.KeyCreated:    "20210622110143",
			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.KeyCreated:    "20220321183214",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		domain.NewContent(nil)},
	id.EmojiZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Generic Emoji",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     api.ValueSyntaxGif,
			api.KeyReadOnly:   api.ValueTrue,
			api.KeyCreated:    "20210504175807",
			api.KeyVisibility: api.ValueVisibilityPublic,
		},
		domain.NewContent(contentEmoji)},
	id.TOCNewTemplateZid: {
		constHeader{
			api.KeyTitle:      "New Menu",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     api.ValueSyntaxZmk,
			api.KeyLang:       api.ValueLangEN,
			api.KeyCreated:    "20210217161829",
			api.KeyVisibility: api.ValueVisibilityCreator,
		},
		domain.NewContent(contentNewTOCZettel)},
	id.MustParse(api.ZidTemplateNewZettel): {
		constHeader{
			api.KeyTitle:      "New Zettel",
			api.KeyRole:       api.ValueRoleZettel,
			api.KeySyntax:     api.ValueSyntaxZmk,
			api.KeyCreated:    "20201028185209",
			api.KeyVisibility: api.ValueVisibilityCreator,
		},
		domain.NewContent(nil)},
	id.MustParse(api.ZidTemplateNewUser): {
		constHeader{
			api.KeyTitle:                       "New User",
			api.KeyRole:                        api.ValueRoleConfiguration,
			api.KeySyntax:                      api.ValueSyntaxNone,
			api.KeyCreated:                     "20201028185209",
			meta.NewPrefix + api.KeyCredential: "",
			meta.NewPrefix + api.KeyUserID:     "",
			meta.NewPrefix + api.KeyUserRole:   api.ValueUserRoleReader,
			api.KeyVisibility:                  api.ValueVisibilityOwner,
		},
		domain.NewContent(nil)},
	id.DefaultHomeZid: {
		constHeader{
			api.KeyTitle:  "Home",
			api.KeyRole:   api.ValueRoleZettel,
			api.KeySyntax: api.ValueSyntaxZmk,
			api.KeyLang:   api.ValueLangEN,
			api.KeyTitle:   "Home",
			api.KeyRole:    api.ValueRoleZettel,
			api.KeySyntax:  api.ValueSyntaxZmk,
			api.KeyLang:    api.ValueLangEN,
			api.KeyCreated: "20210210190757",
		},
		domain.NewContent(contentHomeZettel)},
}

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

//go:embed delete.mustache
var contentDeleteMustache []byte

//go:embed listzettel.mustache
var contentListZettelMustache []byte

//go:embed listroles.mustache
var contentListRolesMustache []byte

//go:embed listtags.mustache
var contentListTagsMustache []byte

//go:embed error.mustache
var contentErrorMustache []byte

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

//go:embed emoji_spin.gif

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

SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
```

=== gopikchr
; URL & Source
: [[https://github.com/gopikchr/gopikchr]]
; License
: MIT License
; Remarks
: Author is [[Zellyn Hunter|https://github.com/zellyn]], he wrote a blog post [[gopikchr: a yakshave|https://zellyn.com/2022/01/gopikchr-a-yakshave/]] about his work.
: Gopikchr was incorporated into the source code of Zettelstore, moving it into package ''zettelstore.de/z/parser/pikchr''.
  Later, the source code was changed to adapt it to the needs of Zettelstore.
  For details, read README.txt in the appropriate source code folder.
```
MIT License

Copyright (c) 2022 gopikchr

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

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

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

=== hoisie/mustache / cbroglie/mustache
; URL & Source
: [[https://github.com/hoisie/mustache]] / [[https://github.com/cbroglie/mustache]]
; License
: MIT License
; Remarks

<ul>
{{#LocLinks}}
{{#Valid}}<li><a href="{{{Zid}}}">{{Zid}}</a></li>{{/Valid}}
{{^Valid}}<li>{{Zid}}</li>{{/Valid}}
{{/LocLinks}}
</ul>
{{/HasLocLinks}}
{{#HasSearchLinks}}
<h3>Searches</h3>
{{#HasQueryLinks}}
<h3>Queries</h3>
<ul>
{{#SearchLinks}}
{{#QueryLinks}}
<li><a href="{{{URL}}}">{{Text}}</a></li>
{{/SearchLinks}}
{{/QueryLinks}}
</ul>
{{/HasSearchLinks}}
{{/HasQueryLinks}}
{{#HasExtLinks}}
<h3>External</h3>
<ul>
{{#ExtLinks}}
<li><a href="{{{.}}}"{{{ExtNewWindow}}}>{{.}}</a></li>
{{/ExtLinks}}
</ul>
{{/HasExtLinks}}
<h3>Unlinked</h3>
<ul>
{{#UnLinks}}
{{{UnLinksContent}}}
<li><a href="{{{URL}}}">{{{Text}}}</a></li>
{{/UnLinks}}
</ul>
<form>
<label for="phrase">Search Phrase</label>
<input class="zs-input" type="text" id="phrase" name="{{QueryKeyPhrase}}" placeholder="Phrase.." value="{{UnLinksPhrase}}">
</form>
<h2>Parts and encodings</h2>
<table>
{{#EvalMatrix}}

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

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

<header>
<h1>{{Title}}</h1>
</header>
<form action="{{{SearchURL}}}">
<input class="zs-input" type="text" placeholder="Search.." name="{{QueryKeySearch}}" value="{{SearchValue}}">
<input class="zs-input" type="text" placeholder="Search.." name="{{QueryKeyQuery}}" value="{{QueryValue}}">
</form>
<ul>
{{#Metas}}<li><a href="{{{URL}}}">{{{Text}}}</a></li>
{{/Metas}}</ul>
{{{Content}}}

<article>
<header>
<h1>{{{HTMLTitle}}}</h1>
<div class="zs-meta">
{{#CanWrite}}<a href="{{{EditURL}}}">Edit</a> &#183;{{/CanWrite}}
{{Zid}} &#183;
<a href="{{{InfoURL}}}">Info</a> &#183;
(<a href="{{{RoleURL}}}">{{RoleText}}</a>)
{{#HasTags}}&#183; {{#Tags}} <a href="{{{URL}}}">{{Text}}</a>{{/Tags}}{{/HasTags}}
{{#CanCopy}}&#183; <a href="{{{CopyURL}}}">Copy</a>{{/CanCopy}}
{{#CanFolge}}&#183; <a href="{{{FolgeURL}}}">Folge</a>{{/CanFolge}}
{{#PrecursorRefs}}<br>Precursor: {{{PrecursorRefs}}}{{/PrecursorRefs}}
{{#HasExtURL}}<br>URL: <a href="{{{ExtURL}}}"{{{ExtNewWindow}}}>{{ExtURL}}</a>{{/HasExtURL}}
{{#Author}}<br>By {{Author}}{{/Author}}
</div>
</header>
{{{Content}}}
</article>
{{#HasFolgeLinks}}
<nav>
<details open>

	"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"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/search"
	"zettelstore.de/z/query"
)

func init() {
	manager.Register("dir", func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
		var log *logger.Logger
		if krnl := kernel.Main; krnl != nil {
			log = krnl.GetLogger(kernel.BoxService).Clone().Str("box", "dir").Int("boxnum", int64(cdata.Number)).Child()

	entry := notify.DirEntry{Zid: newZid}
	dp.updateEntryFromMetaContent(&entry, meta, zettel.Content)

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

func (dp *dirBox) GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
	entry := dp.dirSrv.GetDirEntry(zid)
	if !entry.IsValid() {

	m, err := dp.srvGetMeta(ctx, entry, zid)
	if err != nil {
		return nil, err
	}
	return m, nil
}

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

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

	// The following loop could be parallelized if needed for performance.
	for _, entry := range entries {
		m, err := dp.srvGetMeta(ctx, entry, entry.Zid)
		if err != nil {

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

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

	if err = dp.srvSetZettel(ctx, &newEntry, newZettel); err != nil {
		// "Rollback" rename. No error checking...
		dp.dirSrv.RenameDirEntry(&newEntry, curZid)
		return err
	}
	err = dp.srvDeleteZettel(ctx, curEntry, curZid)
	if err == nil {
		dp.notifyChanged(box.OnDelete, curZid)
		dp.notifyChanged(box.OnUpdate, newZid)
		dp.notifyChanged(box.OnZettel, curZid)
		dp.notifyChanged(box.OnZettel, newZid)
	}
	dp.log.Trace().Zid(curZid).Zid(newZid).Err(err).Msg("RenameZettel")
	return err
}

func (dp *dirBox) CanDeleteZettel(_ context.Context, zid id.Zid) bool {
	if dp.readonly {

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

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

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

type zipBox struct {
	log      *logger.Logger
	number   int
	name     string
	enricher box.Enricher

	}
	defer reader.Close()
	m, err := zb.readZipMeta(reader, zid, entry)
	zb.log.Trace().Err(err).Zid(zid).Msg("GetMeta")
	return m, err
}

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

func (zb *zipBox) ApplyMeta(ctx context.Context, handle box.MetaFunc, constraint search.RetrievePredicate) error {
func (zb *zipBox) ApplyMeta(ctx context.Context, handle box.MetaFunc, constraint query.RetrievePredicate) error {
	reader, err := zip.OpenReader(zb.name)
	if err != nil {
		return err
	}
	defer reader.Close()
	entries := zb.dirSrv.GetDirEntries(constraint)
	zb.log.Trace().Int("entries", int64(len(entries))).Msg("ApplyMeta")

//-----------------------------------------------------------------------------
// 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 manager

import (
	"sync"

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

type arAction int

const (
	arNothing arAction = iota
	arReload
	arUpdate
	arZettel
	arDelete
)

type anteroom struct {
	num     uint64
	next    *anteroom
	waiting map[id.Zid]arAction
	curLoad int

	maxLoad int
}

func newAnterooms(maxLoad int) *anterooms {
	return &anterooms{maxLoad: maxLoad}
}

func (ar *anterooms) Enqueue(zid id.Zid, action arAction) {
	if !zid.IsValid() || action == arNothing || action == arReload {
func (ar *anterooms) EnqueueZettel(zid id.Zid) {
	if !zid.IsValid() {
		return
	}
	ar.mx.Lock()
	defer ar.mx.Unlock()
	if ar.first == nil {
		ar.first = ar.makeAnteroom(zid, action)
		ar.first = ar.makeAnteroom(zid, arZettel)
		ar.last = ar.first
		return
	}
	for room := ar.first; room != nil; room = room.next {
		if room.reload {
			continue // Do not put zettel in reload room
		}
		a, ok := room.waiting[zid]
		if _, ok := room.waiting[zid]; ok {
		if !ok {
			continue
			// Zettel is already waiting.
		}
		switch action {
		case a:
			return
		case arUpdate:
			room.waiting[zid] = action
		case arDelete:
			room.waiting[zid] = action
		}
		return
	}
	if room := ar.last; !room.reload && (ar.maxLoad == 0 || room.curLoad < ar.maxLoad) {
		room.waiting[zid] = action
		room.waiting[zid] = arZettel
		room.curLoad++
		return
	}
	room := ar.makeAnteroom(zid, action)
	room := ar.makeAnteroom(zid, arZettel)
	ar.last.next = room
	ar.last = room
}

func (ar *anterooms) makeAnteroom(zid id.Zid, action arAction) *anteroom {
	c := ar.maxLoad
	if c == 0 {

	ar.first = ar.makeAnteroom(id.Invalid, arReload)
	ar.last = ar.first
}

func (ar *anterooms) Reload(newZids id.Set) uint64 {
	ar.mx.Lock()
	defer ar.mx.Unlock()
	newWaiting := createWaitingSet(newZids, arUpdate)
	newWaiting := createWaitingSet(newZids)
	ar.deleteReloadedRooms()

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

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

func createWaitingSet(zids id.Set, action arAction) map[id.Zid]arAction {
func createWaitingSet(zids id.Set) map[id.Zid]arAction {
	waitingSet := make(map[id.Zid]arAction, len(zids))
	for zid := range zids {
		if zid.IsValid() {
			waitingSet[zid] = action
			waitingSet[zid] = arZettel
		}
	}
	return waitingSet
}

func (ar *anterooms) deleteReloadedRooms() {
	room := ar.first

//-----------------------------------------------------------------------------
// 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 manager

import (
	"testing"

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

func TestSimple(t *testing.T) {
	t.Parallel()
	ar := newAnterooms(2)
	ar.Enqueue(id.Zid(1), arUpdate)
	ar.EnqueueZettel(id.Zid(1))
	action, zid, rno := ar.Dequeue()
	if zid != id.Zid(1) || action != arUpdate || rno != 1 {
		t.Errorf("Expected arUpdate/1/1, but got %v/%v/%v", action, zid, rno)
	if zid != id.Zid(1) || action != arZettel || rno != 1 {
		t.Errorf("Expected arZettel/1/1, but got %v/%v/%v", action, zid, rno)
	}
	action, zid, _ = ar.Dequeue()
	if zid != id.Invalid && action != arDelete {
	_, zid, _ = ar.Dequeue()
	if zid != id.Invalid {
		t.Errorf("Expected invalid Zid, but got %v", zid)
	}
	ar.Enqueue(id.Zid(1), arUpdate)
	ar.Enqueue(id.Zid(2), arUpdate)
	ar.EnqueueZettel(id.Zid(1))
	ar.EnqueueZettel(id.Zid(2))
	if ar.first != ar.last {
		t.Errorf("Expected one room, but got more")
	}
	ar.Enqueue(id.Zid(3), arUpdate)
	ar.EnqueueZettel(id.Zid(3))
	if ar.first == ar.last {
		t.Errorf("Expected more than one room, but got only one")
	}

	count := 0
	for ; count < 1000; count++ {
		action, _, _ = ar.Dequeue()
		if action == arNothing {
			break
		}
	}
	if count != 3 {
		t.Errorf("Expected 3 dequeues, but got %v", count)
	}
}

func TestReset(t *testing.T) {
	t.Parallel()
	ar := newAnterooms(1)
	ar.Enqueue(id.Zid(1), arUpdate)
	ar.EnqueueZettel(id.Zid(1))
	ar.Reset()
	action, zid, _ := ar.Dequeue()
	if action != arReload || zid != id.Invalid {
		t.Errorf("Expected reload & invalid Zid, but got %v/%v", action, zid)
	}
	ar.Reload(id.NewSet(3, 4))
	ar.Enqueue(id.Zid(5), arUpdate)
	ar.Enqueue(id.Zid(5), arDelete)
	ar.EnqueueZettel(id.Zid(5))
	ar.EnqueueZettel(id.Zid(5))
	ar.Enqueue(id.Zid(5), arDelete)
	ar.Enqueue(id.Zid(5), arUpdate)
	if ar.first == ar.last || ar.first.next != ar.last /*|| ar.first.next.next != ar.last*/ {
		t.Errorf("Expected 2 rooms")
	}
	action, zid1, _ := ar.Dequeue()
	if action != arUpdate {
		t.Errorf("Expected arUpdate, but got %v", action)
	if action != arZettel {
		t.Errorf("Expected arZettel, but got %v", action)
	}
	action, zid2, _ := ar.Dequeue()
	if action != arUpdate {
		t.Errorf("Expected arUpdate, but got %v", action)
	if action != arZettel {
		t.Errorf("Expected arZettel, but got %v", action)
	}
	if !(zid1 == id.Zid(3) && zid2 == id.Zid(4) || zid1 == id.Zid(4) && zid2 == id.Zid(3)) {
		t.Errorf("Zids must be 3 or 4, but got %v/%v", zid1, zid2)
	}
	action, zid, _ = ar.Dequeue()
	if zid != id.Zid(5) || action != arUpdate {
		t.Errorf("Expected 5/arUpdate, but got %v/%v", zid, action)
	if zid != id.Zid(5) || action != arZettel {
		t.Errorf("Expected 5/arZettel, but got %v/%v", zid, action)
	}
	action, zid, _ = ar.Dequeue()
	if action != arNothing || zid != id.Invalid {
		t.Errorf("Expected nothing & invalid Zid, but got %v/%v", action, zid)
	}

	ar = newAnterooms(1)
	ar.Reload(id.NewSet(id.Zid(6)))
	action, zid, _ = ar.Dequeue()
	if zid != id.Zid(6) || action != arUpdate {
		t.Errorf("Expected 6/arUpdate, but got %v/%v", zid, action)
	if zid != id.Zid(6) || action != arZettel {
		t.Errorf("Expected 6/arZettel, but got %v/%v", zid, action)
	}
	action, zid, _ = ar.Dequeue()
	if action != arNothing || zid != id.Invalid {
		t.Errorf("Expected nothing & invalid Zid, but got %v/%v", action, zid)
	}

	ar = newAnterooms(1)
	ar.Enqueue(id.Zid(8), arUpdate)
	ar.EnqueueZettel(id.Zid(8))
	ar.Reload(nil)
	action, zid, _ = ar.Dequeue()
	if action != arNothing || zid != id.Invalid {
		t.Errorf("Expected nothing & invalid Zid, but got %v/%v", action, zid)
	}
}

	"context"
	"errors"

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

// Conatains all box.Box related functions

// Location returns some information where the box is located.
func (mgr *Manager) Location() string {
	if len(mgr.boxes) <= 2 {

	return result, nil
}

type metaMap map[id.Zid]*meta.Meta

// SelectMeta returns all zettel meta data that match the selection
// criteria. The result is ordered by descending zettel id.
func (mgr *Manager) SelectMeta(ctx context.Context, s *search.Search) ([]*meta.Meta, error) {
func (mgr *Manager) SelectMeta(ctx context.Context, q *query.Query) ([]*meta.Meta, error) {
	if msg := mgr.mgrLog.Debug(); msg.Enabled() {
		msg.Str("query", s.String()).Msg("SelectMeta")
		msg.Str("query", q.String()).Msg("SelectMeta")
	}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return nil, box.ErrStopped
	}

	searchPred, match := s.RetrieveAndCompileMatch(mgr)
	selected, rejected := metaMap{}, id.Set{}
	handleMeta := func(m *meta.Meta) {
		zid := m.Zid
		if rejected.Contains(zid) {
			mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/alreadyRejected")
			return
		}
		if _, ok := selected[zid]; ok {
			mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/alreadySelected")
			return
		}
		if match(m) {
			selected[zid] = m
			mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/match")
		} else {
			rejected.Zid(zid)
			mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/reject")
		}
	}
	for _, p := range mgr.boxes {
		if err := p.ApplyMeta(ctx, handleMeta, searchPred); err != nil {
			return nil, err
		}
	}
	compSearch := q.RetrieveAndCompile(mgr)
	selected := metaMap{}
	for _, term := range compSearch.Terms {
		rejected := id.Set{}
		handleMeta := func(m *meta.Meta) {
			zid := m.Zid
			if rejected.Contains(zid) {
				mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/alreadyRejected")
				return
			}
			if _, ok := selected[zid]; ok {
				mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/alreadySelected")
				return
			}
			if compSearch.PreMatch(m) && term.Match(m) {
				selected[zid] = m
				mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/match")
			} else {
				rejected.Zid(zid)
				mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/reject")
			}
		}
		for _, p := range mgr.boxes {
			if err := p.ApplyMeta(ctx, handleMeta, term.Retrieve); err != nil {
				return nil, err
			}
		}
	}
	result := make([]*meta.Meta, 0, len(selected))
	for _, m := range selected {
		result = append(result, m)
	}
	return s.Sort(result), nil
	return q.Sort(result), nil
}

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

	case *ast.TagNode:
		data.addText(n.Tag)
		data.itags.Add("#" + strings.ToLower(n.Tag))
	case *ast.LinkNode:
		data.addRef(n.Ref)
	case *ast.EmbedRefNode:
		data.addRef(n.Ref)
	case *ast.CiteNode:
		data.addText(n.Key)
	case *ast.LiteralNode:
		data.addText(string(n.Content))
	}
	return data
}

func (data *collectData) addText(s string) {

//-----------------------------------------------------------------------------
// 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 manager

import (
	"context"
	"strconv"

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

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

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

	if box.DoNotEnrich(ctx) {
		// Enrich is called indirectly via indexer or enrichment is not requested
		// because of other reasons -> ignore this call, do not update meta data
		// because of other reasons -> ignore this call, do not update metadata
		return
	}
	m.Set(api.KeyBoxNumber, strconv.Itoa(boxNumber))
	computePublished(m)
	m.Set(api.KeyBoxNumber, strconv.Itoa(boxNumber))
	mgr.idxStore.Enrich(ctx, m)
}

func computeCreated(zid id.Zid) string {
	if zid <= 10101000000 {
		// A year 0000 is not allowed and therefore an artificaial Zid.
		// In the year 0001, the month must be > 0.
		// In the month 000101, the day must be > 0.
		return "00010101000000"
	}
	seconds := zid % 100
	if seconds > 59 {
		seconds = 59
	}
	zid /= 100
	minutes := zid % 100
	if minutes > 59 {
		minutes = 59
	}
	zid /= 100
	hours := zid % 100
	if hours > 23 {
		hours = 23
	}
	zid /= 100
	day := zid % 100
	if day < 1 {
		day = 1
	}
	zid /= 100
	month := zid % 100
	if month < 1 {
		month = 1
	}
	if month > 12 {
		month = 12
	}
	year := zid / 100
	switch month {
	case 1, 3, 5, 7, 8, 10, 12:
		if day > 31 {
			day = 32
		}
	case 4, 6, 9, 11:
		if day > 30 {
			day = 30
		}
	case 2:
		if year%4 != 0 || (year%100 == 0 && year%400 != 0) {
			if day > 28 {
				day = 28
			}
		} else {
			if day > 29 {
				day = 29
			}
		}
	}
	created := ((((year*100+month)*100+day)*100+hours)*100+minutes)*100 + seconds
	return created.String()
}

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

	// Neither the zettel was modified nor the zettel identifer contains a valid
	// timestamp. In this case do not set the "published" property.
}

			zids, err := mgr.FetchZids(ctx)
			if err == nil {
				start = time.Now()
				if rno := mgr.idxAr.Reload(zids); rno > 0 {
					roomNum = rno
				}
				mgr.idxMx.Lock()
				mgr.idxLastReload = time.Now()
				mgr.idxLastReload = time.Now().Local()
				mgr.idxSinceReload = 0
				mgr.idxMx.Unlock()
			}
		case arUpdate:
			mgr.idxLog.Debug().Zid(zid).Msg("update")
		case arZettel:
			mgr.idxLog.Debug().Zid(zid).Msg("zettel")
			zettel, err := mgr.GetZettel(ctx, zid)
			if err != nil {
				// TODO: on some errors put the zid into a "try later" set
				// Zettel was deleted or is not accessible b/c of other reasons
				mgr.idxLog.Trace().Zid(zid).Msg("delete")
				mgr.idxMx.Lock()
				mgr.idxSinceReload++
				mgr.idxMx.Unlock()
				mgr.idxDeleteZettel(zid)
				continue
			}
			mgr.idxLog.Trace().Zid(zid).Msg("update")
			mgr.idxMx.Lock()
			if arRoomNum == roomNum {
				mgr.idxDurReload = time.Since(start)
			}
			mgr.idxSinceReload++
			mgr.idxMx.Unlock()
			mgr.idxUpdateZettel(ctx, zettel)
		case arDelete:
			mgr.idxLog.Debug().Zid(zid).Msg("delete")
			if _, err := mgr.GetMeta(ctx, zid); err == nil {
				// Zettel was not deleted. This might occur, if zettel was
				// deleted in secondary dirbox, but is still present in
				// first dirbox (or vice versa). Re-index zettel in case
				// a hidden zettel was recovered
				mgr.idxLog.Debug().Zid(zid).Msg("not deleted")
				mgr.idxAr.Enqueue(zid, arUpdate)
			}
			mgr.idxMx.Lock()
			mgr.idxSinceReload++
			mgr.idxMx.Unlock()
			mgr.idxDeleteZettel(zid)
		}
	}
}

func (mgr *Manager) idxSleepService(timer *time.Timer, timerDuration time.Duration) bool {
	select {
	case _, ok := <-mgr.idxReady:

	}
	return true
}

func (mgr *Manager) idxUpdateZettel(ctx context.Context, zettel domain.Zettel) {
	var cData collectData
	cData.initialize()
	collectZettelIndexData(parser.ParseZettel(zettel, "", mgr.rtConfig), &cData)
	collectZettelIndexData(parser.ParseZettel(ctx, zettel, "", mgr.rtConfig), &cData)

	m := zettel.Meta
	zi := store.NewZettelIndex(m.Zid)
	mgr.idxCollectFromMeta(ctx, m, zi, &cData)
	mgr.idxProcessData(ctx, zi, &cData)
	toCheck := mgr.idxStore.UpdateReferences(ctx, zi)
	mgr.idxCheckZettel(toCheck)
}

func (mgr *Manager) idxCollectFromMeta(ctx context.Context, m *meta.Meta, zi *store.ZettelIndex, cData *collectData) {
	for _, pair := range m.Pairs() {
	for _, pair := range m.ComputedPairs() {
		descr := meta.GetDescription(pair.Key)
		if descr.IsComputed() {
		if descr.IsProperty() {
			continue
		}
		switch descr.Type {
		case meta.TypeID:
			mgr.idxUpdateValue(ctx, descr.Inverse, pair.Value, zi)
		case meta.TypeIDSet:
			for _, val := range meta.ListFromValue(pair.Value) {

func (mgr *Manager) idxDeleteZettel(zid id.Zid) {
	toCheck := mgr.idxStore.DeleteZettel(context.Background(), zid)
	mgr.idxCheckZettel(toCheck)
}

func (mgr *Manager) idxCheckZettel(s id.Set) {
	for zid := range s {
		mgr.idxAr.Enqueue(zid, arUpdate)
		mgr.idxAr.EnqueueZettel(zid)
	}
}

	return false
}

func (mgr *Manager) idxEnqueue(reason box.UpdateReason, zid id.Zid) {
	switch reason {
	case box.OnReload:
		mgr.idxAr.Reset()
	case box.OnUpdate:
		mgr.idxAr.Enqueue(zid, arUpdate)
	case box.OnZettel:
		mgr.idxAr.EnqueueZettel(zid)
	case box.OnDelete:
		mgr.idxAr.Enqueue(zid, arDelete)
	default:
		return
	}
	select {
	case mgr.idxReady <- struct{}{}:
	default:
	}

	ms.mx.RLock()
	defer ms.mx.RUnlock()
	result := ms.selectWithPred(prefix, strings.HasPrefix)
	l := len(prefix)
	if l > 14 {
		return result
	}
	minZid, err := id.Parse(prefix + "00000000000000"[:14-l])
	maxZid, err := id.Parse(prefix + "99999999999999"[:14-l])
	if err != nil {
		return result
	}
	var minZid id.Zid
	if l < 14 && prefix == "0000000000000"[:l] {
		minZid = id.Zid(1)
	} else {
	maxZid, err := id.Parse(prefix + "99999999999999"[:14-l])
	if err != nil {
		return result
		minZid, err = id.Parse(prefix + "00000000000000"[:14-l])
		if err != nil {
			return result
		}
	}
	for zid, zi := range ms.idx {
		if minZid <= zid && zid <= maxZid {
			addBackwardZids(result, zid, zi)
		}
	}
	return result

import (
	"context"
	"io"

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

// Stats records statistics about the store.
type Stats struct {
	// Zettel is the number of zettel managed by the indexer.
	Zettel int

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

	// Words count the different words stored in the store.
	Words uint64

	// Urls count the different URLs stored in the store.
	Urls uint64
}

// Store all relevant zettel data. There may be multiple implementations, i.e.
// memory-based, file-based, based on SQLite, ...
type Store interface {
	search.Searcher
	query.Searcher

	// Entrich metadata with data from store.
	Enrich(ctx context.Context, m *meta.Meta)

	// UpdateReferences for a specific zettel.
	// Returns set of zettel identifier that must also be checked for changes.
	UpdateReferences(context.Context, *ZettelIndex) id.Set

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

func init() {
	manager.Register(
		"mem",
		func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
			return &memBox{

	}
	meta := zettel.Meta.Clone()
	meta.Zid = zid
	zettel.Meta = meta
	mb.zettel[zid] = zettel
	mb.curBytes = newBytes
	mb.mx.Unlock()
	mb.notifyChanged(box.OnUpdate, zid)
	mb.notifyChanged(box.OnZettel, zid)
	mb.log.Trace().Zid(zid).Msg("CreateZettel")
	return zid, nil
}

func (mb *memBox) GetZettel(_ context.Context, zid id.Zid) (domain.Zettel, error) {
	mb.mx.RLock()
	zettel, ok := mb.zettel[zid]

	if !ok {
		return nil, box.ErrNotFound
	}
	mb.log.Trace().Msg("GetMeta")
	return zettel.Meta.Clone(), nil
}

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

func (mb *memBox) ApplyMeta(ctx context.Context, handle box.MetaFunc, constraint search.RetrievePredicate) error {
func (mb *memBox) ApplyMeta(ctx context.Context, handle box.MetaFunc, constraint query.RetrievePredicate) error {
	mb.mx.RLock()
	defer mb.mx.RUnlock()
	mb.log.Trace().Int("entries", int64(len(mb.zettel))).Msg("ApplyMeta")
	for zid, zettel := range mb.zettel {
		if constraint(zid) {
			m := zettel.Meta.Clone()
			mb.cdata.Enricher.Enrich(ctx, m, mb.cdata.Number)

		return box.ErrCapacity
	}

	zettel.Meta = m
	mb.zettel[m.Zid] = zettel
	mb.curBytes = newBytes
	mb.mx.Unlock()
	mb.notifyChanged(box.OnUpdate, m.Zid)
	mb.notifyChanged(box.OnZettel, m.Zid)
	mb.log.Trace().Msg("UpdateZettel")
	return nil
}

func (*memBox) AllowRenameZettel(context.Context, id.Zid) bool { return true }

func (mb *memBox) RenameZettel(_ context.Context, curZid, newZid id.Zid) error {

	meta := zettel.Meta.Clone()
	meta.Zid = newZid
	zettel.Meta = meta
	mb.zettel[newZid] = zettel
	delete(mb.zettel, curZid)
	mb.mx.Unlock()
	mb.notifyChanged(box.OnDelete, curZid)
	mb.notifyChanged(box.OnUpdate, newZid)
	mb.notifyChanged(box.OnZettel, curZid)
	mb.notifyChanged(box.OnZettel, newZid)
	mb.log.Trace().Msg("RenameZettel")
	return nil
}

func (mb *memBox) CanDeleteZettel(_ context.Context, zid id.Zid) bool {
	mb.mx.RLock()
	_, ok := mb.zettel[zid]

	if !found {
		mb.mx.Unlock()
		return box.ErrNotFound
	}
	delete(mb.zettel, zid)
	mb.curBytes -= oldZettel.Length()
	mb.mx.Unlock()
	mb.notifyChanged(box.OnDelete, zid)
	mb.notifyChanged(box.OnZettel, zid)
	mb.log.Trace().Msg("DeleteZettel")
	return nil
}

func (mb *memBox) ReadStats(st *box.ManagedBoxStats) {
	st.ReadOnly = false
	mb.mx.RLock()
	st.Zettel = len(mb.zettel)
	mb.mx.RUnlock()
	mb.log.Trace().Int("zettel", int64(st.Zettel)).Msg("ReadStats")
}

	"strings"
	"sync"

	"zettelstore.de/z/box"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/search"
	"zettelstore.de/z/query"
	"zettelstore.de/z/strfun"
)

type entrySet map[id.Zid]*DirEntry

// directoryState signal the internal state of the service.
//

	if ds.entries == nil {
		return 0
	}
	return len(ds.entries)
}

// GetDirEntries returns a list of directory entries, which satisfy the given constraint.
func (ds *DirService) GetDirEntries(constraint search.RetrievePredicate) []*DirEntry {
func (ds *DirService) GetDirEntries(constraint query.RetrievePredicate) []*DirEntry {
	ds.mx.RLock()
	defer ds.mx.RUnlock()
	if ds.entries == nil {
		return nil
	}
	result := make([]*DirEntry, 0, len(ds.entries))
	for zid, entry := range ds.entries {

			ds.onDestroyDirectory()
			ds.log.Error().Str("path", ds.dirPath).Msg("Zettel directory missing")
		case Update:
			ds.mx.Lock()
			zid := ds.onUpdateFileEvent(ds.entries, ev.Name)
			ds.mx.Unlock()
			if zid != id.Invalid {
				ds.notifyChange(box.OnUpdate, zid)
				ds.notifyChange(box.OnZettel, zid)
			}
		case Delete:
			ds.mx.Lock()
			ds.onDeleteFileEvent(ds.entries, ev.Name)
			zid := ds.onDeleteFileEvent(ds.entries, ev.Name)
			ds.mx.Unlock()
			if zid != id.Invalid {
				ds.notifyChange(box.OnZettel, zid)
			}
		default:
			ds.log.Warn().Str("event", fmt.Sprintf("%v", ev)).Msg("Unknown zettel notification event")
		}
	}
}

func getNewZids(entries entrySet) id.Slice {
	zids := make(id.Slice, 0, len(entries))
	for zid := range entries {
		zids = append(zids, zid)
	}
	return zids
}

func (ds *DirService) onCreateDirectory(zids id.Slice, prevEntries entrySet) {
	for _, zid := range zids {
		ds.notifyChange(box.OnUpdate, zid)
		ds.notifyChange(box.OnZettel, zid)
		delete(prevEntries, zid)
	}

	// These were previously stored, by are not found now.
	// Notify system that these were deleted, e.g. for updating the index.
	for zid := range prevEntries {
		ds.notifyChange(box.OnDelete, zid)
		ds.notifyChange(box.OnZettel, zid)
	}
}

func (ds *DirService) onDestroyDirectory() {
	ds.mx.Lock()
	entries := ds.entries
	ds.entries = nil
	ds.state = dsMissing
	ds.mx.Unlock()
	for zid := range entries {
		ds.notifyChange(box.OnDelete, zid)
		ds.notifyChange(box.OnZettel, zid)
	}
}

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

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

	entry := fetchdirEntry(entries, zid)
	dupName1, dupName2 := ds.updateEntry(entry, name)
	if dupName1 != "" {
		ds.log.Warn().Str("name", dupName1).Msg("Duplicate content (is ignored)")
		if dupName2 != "" {
			ds.log.Warn().Str("name", dupName2).Msg("Duplicate content (is ignored)")
		}
		return id.Invalid
	}
	return zid
}

func (ds *DirService) onDeleteFileEvent(entries entrySet, name string) {
func (ds *DirService) onDeleteFileEvent(entries entrySet, name string) id.Zid {
	if entries == nil {
		return
		return id.Invalid
	}
	zid := seekZid(name)
	if zid == id.Invalid {
		return
		return id.Invalid
	}
	entry, found := entries[zid]
	if !found {
		return
		return zid
	}
	for i, dupName := range entry.UselessFiles {
		if dupName == name {
			removeDuplicate(entry, i)
			return
			return zid
		}
	}
	if name == entry.ContentName {
		entry.ContentName = ""
		entry.ContentExt = ""
		ds.replayUpdateUselessFiles(entry)
	} else if name == entry.MetaName {
		entry.MetaName = ""
		ds.replayUpdateUselessFiles(entry)
	}
	if entry.ContentName == "" && entry.MetaName == "" {
		delete(entries, zid)
		ds.notifyChange(box.OnDelete, zid)
	}
	return zid
}

func removeDuplicate(entry *DirEntry, i int) {
	if len(entry.UselessFiles) == 1 {
		entry.UselessFiles = nil
		return
	}

	"testing"

	"zettelstore.de/c/api"
	"zettelstore.de/z/domain/id"
	_ "zettelstore.de/z/parser/blob"       // Allow to use BLOB 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/pikchr"     // Allow to use pikchr 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) {
	testcases := []struct {
		name string

		}
	}
}

func TestNewExtIsBetter(t *testing.T) {
	extVals := []string{
		// Main Formats
		api.ValueSyntaxZmk, "markdown", "md",
		api.ValueSyntaxZmk, "pikchr", "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) 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 notify

			return fsdn.processDirEvent(ev)
		}
		return fsdn.processFileEvent(ev)
	}
	return true
}

func (fsdn *fsdirNotifier) processDirEvent(ev *fsnotify.Event) bool {
const deleteFsOps = fsnotify.Remove | fsnotify.Rename
	const deleteFsDirOps = fsnotify.Remove | fsnotify.Rename
const updateFsOps = fsnotify.Create | fsnotify.Write

func (fsdn *fsdirNotifier) processDirEvent(ev *fsnotify.Event) bool {
	if ev.Op&deleteFsOps != 0 {
	if ev.Op&deleteFsDirOps != 0 {
		fsdn.log.Debug().Str("name", fsdn.path).Msg("Directory removed")
		fsdn.base.Remove(fsdn.path)
		select {
		case fsdn.events <- Event{Op: Destroy}:
		case <-fsdn.done:
			return false
		}
		return true
	}
	if ev.Op&fsnotify.Create != 0 {
	} else if ev.Op&fsnotify.Create != 0 {
		err := fsdn.base.Add(fsdn.path)
		if err != nil {
			fsdn.log.IfErr(err).Str("name", fsdn.path).Msg("Unable to add directory")
			select {
			case fsdn.events <- Event{Op: Error, Err: err}:
			case <-fsdn.done:
				return false
			}
		}
		fsdn.log.Debug().Str("name", fsdn.path).Msg("Directory added")
		return listDirElements(fsdn.log, fsdn.fetcher, fsdn.events, fsdn.done)
	} else {
		fsdn.log.Trace().Str("name", ev.Name).Str("op", ev.Op.String()).Msg("Directory processed")
	}
	return true
}

func (fsdn *fsdirNotifier) processFileEvent(ev *fsnotify.Event) bool {
	if ev.Op&deleteFsOps != 0 {
		fsdn.log.Trace().Str("name", ev.Name).Uint("op", uint64(ev.Op)).Msg("File deleted")
	const deleteFsFileOps = fsnotify.Remove
	const updateFsFileOps = fsnotify.Create | fsnotify.Write | fsnotify.Rename
		select {
		case fsdn.events <- Event{Op: Delete, Name: filepath.Base(ev.Name)}:
		case <-fsdn.done:
			return false
		}

		return true
	}
	if ev.Op&updateFsOps != 0 {
	if ev.Op&updateFsFileOps != 0 {
		if fi, err := os.Lstat(ev.Name); err != nil || !fi.Mode().IsRegular() {
			return true
		}
		fsdn.log.Trace().Str("name", ev.Name).Uint("op", uint64(ev.Op)).Msg("File updated")
		fsdn.log.Trace().Str("name", ev.Name).Str("op", ev.Op.String()).Msg("File updated")
		select {
		case fsdn.events <- Event{Op: Update, Name: filepath.Base(ev.Name)}:
		case <-fsdn.done:
			return false
		}
	} else if ev.Op&deleteFsFileOps != 0 {
		fsdn.log.Trace().Str("name", ev.Name).Str("op", ev.Op.String()).Msg("File deleted")
		select {
		case fsdn.events <- Event{Op: Delete, Name: filepath.Base(ev.Name)}:
		case <-fsdn.done:
			return false
		}
	} else {
		fsdn.log.Trace().Str("name", ev.Name).Str("op", ev.Op.String()).Msg("File processed")
	}
	return true
}

func (fsdn *fsdirNotifier) Close() {
	close(fsdn.done)
}

//-----------------------------------------------------------------------------
// 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 cmd

import (
	"context"
	"flag"
	"fmt"
	"io"
	"os"

	"zettelstore.de/c/api"
	"zettelstore.de/z/domain"

func cmdFile(fs *flag.FlagSet) (int, error) {
	enc := fs.Lookup("t").Value.String()
	m, inp, err := getInput(fs.Args())
	if m == nil {
		return 2, err
	}
	z := parser.ParseZettel(
		context.Background(),
		domain.Zettel{
			Meta:    m,
			Content: domain.NewContent(inp.Src[inp.Pos:]),
		},
		m.GetDefault(api.KeySyntax, api.ValueSyntaxZmk),
		nil,
	)

//-----------------------------------------------------------------------------
// 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 cmd

import (
	"context"
	"flag"
	"net/http"

	"zettelstore.de/z/auth"
	"zettelstore.de/z/box"
	"zettelstore.de/z/config"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/usecase"
	"zettelstore.de/z/web/adapter/api"
	"zettelstore.de/z/web/adapter/webui"
	"zettelstore.de/z/web/server"
)

		exitCode = 1
	}
	kernel.Main.WaitForShutdown()
	return exitCode, err
}

func setupRouting(webSrv server.Server, boxManager box.Manager, authManager auth.Manager, rtConfig config.Config) {
	protectedBoxManager, authPolicy := authManager.BoxWithPolicy(webSrv, boxManager, rtConfig)
	protectedBoxManager, authPolicy := authManager.BoxWithPolicy(boxManager, rtConfig)
	kern := kernel.Main
	webLog := kern.GetLogger(kernel.WebService)
	a := api.New(
		webLog.Clone().Str("adapter", "api").Child(),
		webSrv, authManager, authManager, webSrv, rtConfig, authPolicy)
		webSrv, authManager, authManager, rtConfig, authPolicy)
	wui := webui.New(
		webLog.Clone().Str("adapter", "wui").Child(),
		webSrv, authManager, rtConfig, authManager, boxManager, authPolicy)

	var getUser getUserImpl
	authLog := kern.GetLogger(kernel.AuthService)
	ucLog := kern.GetLogger(kernel.CoreService).WithUser(webSrv)
	ucAuthenticate := usecase.NewAuthenticate(authLog, authManager, authManager, boxManager)
	ucIsAuth := usecase.NewIsAuthenticated(ucLog, webSrv, authManager)
	ucCreateZettel := usecase.NewCreateZettel(ucLog, rtConfig, protectedBoxManager)
	logAuth := kern.GetLogger(kernel.AuthService)
	logUc := kern.GetLogger(kernel.CoreService).WithUser(&getUser)
	ucAuthenticate := usecase.NewAuthenticate(logAuth, authManager, authManager, boxManager)
	ucIsAuth := usecase.NewIsAuthenticated(logUc, &getUser, authManager)
	ucCreateZettel := usecase.NewCreateZettel(logUc, rtConfig, protectedBoxManager)
	ucGetMeta := usecase.NewGetMeta(protectedBoxManager)
	ucGetAllMeta := usecase.NewGetAllMeta(protectedBoxManager)
	ucGetZettel := usecase.NewGetZettel(protectedBoxManager)
	ucParseZettel := usecase.NewParseZettel(rtConfig, ucGetZettel)
	ucListMeta := usecase.NewListMeta(protectedBoxManager)
	ucEvaluate := usecase.NewEvaluate(rtConfig, ucGetZettel, ucGetMeta, ucListMeta)
	ucListSyntax := usecase.NewListSyntax(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)
	ucDelete := usecase.NewDeleteZettel(logUc, protectedBoxManager)
	ucUpdate := usecase.NewUpdateZettel(logUc, protectedBoxManager)
	ucRename := usecase.NewRenameZettel(logUc, protectedBoxManager)
	ucUnlinkedRefs := usecase.NewUnlinkedReferences(protectedBoxManager, rtConfig)
	ucRefresh := usecase.NewRefresh(ucLog, protectedBoxManager)
	ucRefresh := usecase.NewRefresh(logUc, protectedBoxManager)
	ucVersion := usecase.NewVersion(kernel.Main.GetConfig(kernel.CoreService, kernel.CoreVersion).(string))

	webSrv.Handle("/", wui.MakeGetRootHandler(protectedBoxManager))
	if assetDir := kern.GetConfig(kernel.WebService, kernel.WebAssetDir).(string); assetDir != "" {
		const assetPrefix = "/assets/"
		webSrv.Handle(assetPrefix, http.StripPrefix(assetPrefix, http.FileServer(http.Dir(assetDir))))
	}

	// 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, 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, 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(
	webSrv.AddListRoute('h', server.MethodGet, wui.MakeListHTMLMetaHandler(ucListMeta, &ucEvaluate))
		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('q', server.MethodGet, a.MakeQueryHandler(ucListMeta))
	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))

		webSrv.AddZettelRoute('z', server.MethodMove, a.MakeRenameZettelHandler(&ucRename))
	}

	if authManager.WithAuth() {
		webSrv.SetUserRetriever(usecase.NewGetUserByZid(boxManager))
	}
}

type getUserImpl struct{}

func (*getUserImpl) GetUser(ctx context.Context) *meta.Meta { return server.GetUser(ctx) }

//-----------------------------------------------------------------------------
// 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 cmd

import (
	"crypto/sha256"
	"errors"
	"flag"
	"fmt"
	"net"
	"net/url"
	"os"
	"runtime/debug"
	"strconv"
	"strings"
	"time"

	"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"

			cfg.Delete(key)
		}
	}
}

const (
	keyAdminPort         = "admin-port"
	keyAssetDir          = "asset-dir"
	keyBaseURL           = "base-url"
	keyDebug             = "debug-mode"
	keyDefaultDirBoxType = "default-dir-box-type"
	keyInsecureCookie    = "insecure-cookie"
	keyListenAddr        = "listen-addr"
	keyLogLevel          = "log-level"
	keyMaxRequestSize    = "max-request-size"
	keyOwner             = "owner"

		}
		ok = setConfigValue(ok, kernel.BoxService, key, val)
	}

	ok = setConfigValue(
		ok, kernel.WebService, kernel.WebListenAddress,
		cfg.GetDefault(keyListenAddr, "127.0.0.1:23123"))
	if val, found := cfg.Get(keyBaseURL); found {
		ok = setConfigValue(ok, kernel.WebService, kernel.WebBaseURL, val)
	}
	if val, found := cfg.Get(keyURLPrefix); found {
	ok = setConfigValue(ok, kernel.WebService, kernel.WebURLPrefix, cfg.GetDefault(keyURLPrefix, "/"))
		ok = setConfigValue(ok, kernel.WebService, kernel.WebURLPrefix, val)
	}
	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 val, found := cfg.Get(keyAssetDir); found {
		ok = setConfigValue(ok, kernel.WebService, kernel.WebAssetDir, val)
	}

	if !ok {
		return errors.New("unable to set configuration")
	}
	return 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
	}
	cfg.Delete("secret")
	secret = fmt.Sprintf("%x", sha256.Sum256([]byte(secret)))

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

}

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 {
	info := retrieveVCSInfo(buildVersion)
	fullVersion := retrieveFullVersion(buildVersion)
	kernel.Main.SetConfig(kernel.CoreService, kernel.CoreProgname, progName)
	fullVersion := info.revision
	if info.dirty {
		fullVersion += "-dirty"
	}
	kernel.Main.Setup(progName, fullVersion, info.time)
	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:]...)
}

type vcsInfo struct {
	revision string
	dirty    bool
	time     time.Time
}

func retrieveFullVersion(version string) string {
func retrieveVCSInfo(version string) vcsInfo {
	buildTime := time.Date(1970, 1, 1, 0, 0, 0, 0, time.UTC)
	info, ok := debug.ReadBuildInfo()
	if !ok {
		return version
		return vcsInfo{revision: version, dirty: false, time: buildTime}
	}
	var revision, dirty string
	result := vcsInfo{time: buildTime}
	for _, kv := range info.Settings {
		switch kv.Key {
		case "vcs.revision":
			revision = "+" + kv.Value
			revision := "+" + kv.Value
			if len(revision) > 11 {
				revision = revision[:11]
			}
			result.revision = version + revision
		case "vcs.modified":
			if kv.Value == "true" {
				dirty = "-dirty"
				result.dirty = true
			}
		case "vcs.time":
			if t, err := time.Parse(time.RFC3339, kv.Value); err == nil {
				result.time = t
			}
		}
	}
	return version + revision + dirty
	return result
}

	_ "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/markdown"   // Allow to use markdown parser.
	_ "zettelstore.de/z/parser/none"       // Allow to use none parser.
	_ "zettelstore.de/z/parser/pikchr"     // Allow to use PIC/Pikchr parser.
	_ "zettelstore.de/z/parser/plain"      // Allow to use plain parser.
	_ "zettelstore.de/z/parser/zettelmark" // Allow to use zettelmark parser.
)

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

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

import (
	"context"
	"zettelstore.de/c/api"

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

// Key values that are supported by Config.Get
const (
	KeyFooterHTML = "footer-html"
	// api.KeyLang
	KeyMarkerExternal = "marker-external"
)

// 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
	// Get returns the value of the given key. It searches first in the given metadata,
	// then in the data of the current user, and at last in the system-wide data.
	Get(ctx context.Context, m *meta.Meta, key string) string

	// GetDefaultLang returns the current value of the "default-lang" key.
	GetDefaultLang() string
	// AddDefaultValues enriches the given meta data with its default values.
	AddDefaultValues(context.Context, *meta.Meta) *meta.Meta

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

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

	// 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.
	GetZettelFileSyntax() []string

	// GetMarkerExternal returns the current value of the "marker-external" key.
	GetMarkerExternal() string

	// GetFooterHTML returns HTML code that should be embedded into the footer
	// of each WebUI page.
	GetFooterHTML() string
}

// AuthConfig are relevant configuration values for authentication.
type AuthConfig interface {
	// GetSimpleMode returns true if system tuns in simple-mode.
	GetSimpleMode() bool

	// 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
}

// 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()
}

id: 00001004010000
title: Zettelstore startup configuration
role: manual
tags: #configuration #manual #zettelstore
syntax: zmk
created: 20210126175322
modified: 20220419193611
modified: 20220914183434

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.

The file for startup configuration must be created via a text editor in advance.

The syntax of the configuration file is the same as for any zettel metadata.
The following keys are supported:

; [!admin-port|''admin-port'']
: Specifies the TCP port through which you can reach the [[administrator console|00001004100000]].
  A value of ""0"" (the default) disables the administrator console.
  The administrator console will only be enabled if Zettelstore is started with the [[''run'' sub-command|00001004051000]].

  On most operating systems, the value must be greater than ""1024"" unless you start Zettelstore with the full privileges of a system administrator (which is not recommended).

  Default: ""0""
; [!asset-dir|''asset-dir'']
: Allows to specify a directory whose files are allowed be transferred directly with the help of the web server.
  The URL prefix for these files is ''/assets/''.
  You can use this if you want to transfer files that are too large for a note to users.
  Examples would be presentation files, PDF files, music files or video files.

  Files within the given directory will not be managed by Zettelstore.[^They will be managed by Zettelstore just in the case that the directory is one of the configured [[boxes|#box-uri-x]].]

  If you specify only the URL prefix, then the contents of the directory are listed to the user.
  To avoid this, create an empty file in the directory named ""index.html"".

  Default: """", no asset directory is set, the URL prefix ''/assets/'' is invalid.
; [!base-url|''base-url'']
: Sets the absolute base URL for the service.

  Note: [[''url-prefix''|#url-prefix]] must be the suffix of ''base-url'', otherwise the web service will not start.
  
  Default: ""http://127.0.0.1:23123/"".
; [!box-uri-x|''box-uri-X''], where __X__ is a number greater or equal to one
: Specifies a [[box|00001004011200]] where zettel are stored.
  During startup __X__ is counted up, starting with one, until no key is found.
  This allows to configure more than one box.

  If no ''box-uri-1'' key is given, the overall effect will be the same as if only ''box-uri-1'' was specified with the value ""dir://.zettel"".
  In this case, even a key ''box-uri-2'' will be ignored.

  ''token-lifetime-html'' specifies the lifetime for the HTML views.
  It is automatically extended, when a new HTML view is rendered.
  Default: ""60"".
; [!url-prefix|''url-prefix'']
: Add the given string as a prefix to the local part of a Zettelstore local URL/URI when rendering zettel representations.
  Must begin and end with a slash character (""''/''"", U+002F).

  Note: ''url-prefix'' must be the suffix of [[''base-url''|#base-url]], otherwise the web service will not start.

  Default: ""/"".

  This allows to use a forwarding proxy [[server|00001010090100]] in front of the Zettelstore.
; [!verbose-mode|''verbose-mode'']
: Be more verbose when logging data, if set to a [[true value|00001006030500]].

  Default: ""false""

id: 00001004020000
title: Configure the running Zettelstore
role: manual
tags: #configuration #manual #zettelstore
syntax: zmk
created: 20210126175322
modified: 20220628110920
modified: 20220827180953

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.
  Can be overwritten in a zettel with [[meta key|00001006020000]] ''copyright''.

  Default: (the empty string).
; [!default-lang|''default-lang'']
: Default language to be used when displaying content.
  Can be overwritten in a zettel with [[meta key|00001006020000]] ''lang''. Default: ""en"".

  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-visibility|''default-visibility'']
: Visibility to be used, if zettel does not specify a value for the [[''visibility''|00001006020000#visibility]] metadata key.
  Default: ""login"".

  Default: (the empty string).
; [!home-zettel|''home-zettel'']
: Specifies the identifier of the zettel, that should be presented for the default view / home view.
  If not given or if the identifier does not identify a zettel, the zettel with the identifier ''00010000000000'' is shown.
; [!marker-external|''marker-external'']
: Some HTML code that is displayed after a [[reference to external material|00001007040310]].
  Default: ""&\#10138;"", to display a ""➚"" sign.
; [!lang|''lang'']
: Language to be used when displaying content.

  Default: ""en"".

  This value is used as a default value, if it is not set in an user's zettel or in a zettel.
  It 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]].
; [!max-transclusions|''max-transclusions'']
: Maximum number of indirect transclusion.
  This is used to avoid an exploding ""transclusion bomb"", a form of a [[billion laughs attack|https://en.wikipedia.org/wiki/Billion_laughs_attack]].
  Default: ""1024"".
; [!site-name|''site-name'']
: Name of the Zettelstore instance.
  Will be used when displaying some lists.

id: 00001004101000
title: List of supported commands of the administrator console
role: manual
tags: #configuration #manual #zettelstore
syntax: zmk
modified: 20220218133526
modified: 20220823194553

; [!bye|''bye'']
: Closes the connection to the administrator console.
; [!config|''config SERVICE'']
: Displays all valid configuration keys for the given service.

  If a key ends with the hyphen-minus character (""''-''"", U+002D), the key denotes a list value.

  Other values for ''PROFILE'' are: ''goroutine'', ''heap'', ''allocs'', ''threadcreate'', ''block'', and ''mutex''.
  In the future, more values may be appropriate.
  See the [[Go documentation|https://pkg.go.dev/runtime/pprof#Profile]] for details.

  This feature is dependent on the internal implementation language of Zettelstore, Go.
  It may be removed without any further notice at any time.
  In most cases, it is a tool for software developers to optimize Zettelstore's internal workings.
; [!refresh|''refresh'']
: Refresh all internal data about zettel.
; [!restart|''restart SERVICE'']
: Restart the given service and all other that depend on this.
; [!services|''services'']
: Displays s list of all available services and their current status.
; [!set-config|''set-config SERVICE KEY VALUE'']
: Sets a single configuration value for the next configuration of a given service.
  It will become effective if the service is restarted.

id: 00001005090000
title: List of predefined zettel
role: manual
tags: #manual #reference #zettelstore
syntax: zmk
created: 20210126175322
modified: 20220321192401
modified: 20220909180240

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
| [[00000000010300]] | Zettelstore List Zettel 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 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 
| [[00000000029000]] | Zettelstore Role to CSS Map | [[Maps|00001017000000#role-css]] [[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: 00001006020000
title: Supported Metadata Keys
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210126175322
modified: 20220810111207
modified: 20220915181826

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]] and the value of [[''content-tags''|#content-tags]].
; [!author|''author'']
: A string value describing the author of a zettel.
  If given, it will be shown in the [[web user interface|00001014000000]] for the zettel.
; [!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''|#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]].
; [!content-tags|''content-tags'']
: A property that contains all [[inline tags|00001007040000#tag]] defined within the content.
; [!copyright|''copyright'']
: Defines a copyright string that will be encoded.
  If not given, the value ''default-copyright'' from the  [[configuration zettel|00001004020000#default-copyright]] will be used.
; [!created|''created'']
: Date and time when a zettel was created through Zettelstore.
  If you create a zettel with an editor software outside Zettelstore, you should set it manually to an appropriate value.

  This is a computed value.
  There is no need to set it via Zettelstore.
  
  If it is not stored within a zettel, it will be computed based on the value of the [[Zettel Identifier|00001006050000]]: if it contains a value >= 19700101000000, it will be coerced to da date/time; otherwise the version time of the running software will be used.

  Please note that the value von ''created'' will be different (in most cases) to the value of [[''id''|#id]] / the zettel identifier, because it is exact up to the second.
  When calculating a zettel identifier, Zettelstore tries to set the second value to zero, if possible.
; [!credential|''credential'']
: Contains the hashed password, as it was emitted by [[``zettelstore password``|00001004051400]].
  It is internally created by hashing the password, the [[zettel identifier|00001006050000]], and the value of the ''ident'' key.

  It is only used for zettel with a ''role'' value of ""user"".
; [!dead|''dead'']
: Property that contains all references that does __not__ identify a zettel.
; [!folge|''folge'']
: Is a property that contains identifier of all zettel that reference this zettel through the [[''precursor''|#precursor]] value.
; [!forward|''forward'']
: Property that contains all references that identify another zettel within the content of the zettel.
; [!id|''id'']
: Contains the [[zettel identifier|00001006050000]], as given by the Zettelstore.
  It cannot be set manually, because it is a computed value.
; [!lang|''lang'']
: Language for the zettel.
  Mostly used for HTML rendering of the zettel.
  If not given, the value ''default-lang'' from the  [[configuration zettel|00001004020000#default-lang]] will be used.

  If not given, the value ''lang'' from the zettel of the [[current user|00001010040200]] will be used.
  If that value is also not available, it is read from the [[configuration zettel|00001004020000#lang]] will be used.
  Use values according to the language definition of [[RFC-5646|https://tools.ietf.org/html/rfc5646]].
; [!license|''license'']
: Defines a license string that will be rendered.
  If not given, the value ''default-license'' from the [[configuration zettel|00001004020000#default-license]] will be used.
; [!modified|''modified'']
: Date and time when a zettel was modified through Zettelstore.
  If you edit a zettel with an editor software outside Zettelstore, you should set it manually to an appropriate value.

  This is a computed value.
  There is no need to set it via Zettelstore.
; [!precursor|''precursor'']
: References zettel for which this zettel is a ""Folgezettel"" / follow-up zettel.
  Basically the inverse of key [[''folge''|#folge]].
; [!published|''published'']
: This property contains the timestamp of the mast modification / creation of the zettel.
  If [[''modified''|#modified]] is set, it contains the same value.
  If [[''modified''|#modified]] is set with a valid timestamp, it contains the its value.
  Otherwise, if [[''created''|#created]] is set with a valid timestamp, it contains the its value.
  Otherwise, if the zettel identifier contains a valid timestamp, the identifier is used.
  In all other cases, this property is not set.

  It can be used for [[sorting|00001012052000]] zettel based on their publication date.
  It can be used for [[sorting|00001007700000]] zettel based on their publication date.

  It is a computed value.
  There is no need to set it via Zettelstore.
; [!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'']

id: 00001006031000
title: Credential Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20220914130324

Values of this type denote a credential value, e.g. an encrypted password.

=== Allowed values
All printable characters are allowed.
Since a credential contains some kind of secret, the sequence of characters might have some hidden syntax to be interpreted by other parts of Zettelstore.

=== Match operator
A credential never matches to any other value.
=== Query operators
A credential never compares to any other value.
A comparison will never match in any way.

=== Sorting
If a list of zettel should be sorted based on a credential value, the identifier of the respective zettel is used instead.

id: 00001006031500
title: EString Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20220914130448

Values of this type are just a sequence of character, possibly an empty sequence.

An EString is the most general metadata key type, as it places no restrictions to the character sequence.[^Well, there are some minor restrictions that follow from the [[metadata syntax|00001006010000]].]

=== Allowed values
All printable characters are allowed.

=== Match operator
=== Query operator
A value matches an EString value, if the first value is part of the EString value.
This check is done case-insensitive.
All comparisons are done case-insensitive, i.e. ""hell"" will be the prefix of ""Hello"".

For example, ""hell"" matches ""Hello"".

=== Sorting
To sort two values, the underlying encoding is used to determine which value is less than the other.

Uppercase letters are typically interpreted as less than their corresponding lowercase letters, i.e. ``A < a``.

Comparison is done character-wise by finding the first difference in the respective character sequence.

id: 00001006032000
title: Identifier Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20220914134914

Values of this type denote a [[zettel identifier|00001006050000]].

=== Allowed values
Must be a sequence of 14 digits (""0""--""9"").

=== Match operator
=== Query operator
A value matches an identifier value, if the first value is the prefix of the identifier value.

Comparison is done with the string representation of the identifiers.
For example, ""000010"" matches ""[[00001006032000]]"".

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

If both values are identifiers, this works well because both have the same length.

id: 00001006032500
title: IdentifierSet Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20220111103731
modified: 20220914131354

Values of this type denote a (sorted) set of [[zettel identifier|00001006050000]].

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

=== Allowed values
Must be at least one sequence of 14 digits (""0""--""9""), separated by space characters.

=== Match operator
A value matches an identifier set value, if the first value is a prefix of one of the identifier value.
=== Query operator
A value matches an identifier set value, if the value matches any of the identifier set values.

For example, ""000010"" matches ""[[00001006032000]] [[00001006032500]]"".
For example, ""000010060325"" is a prefix ""[[00001006032000]] [[00001006032500]]"".

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

id: 00001006033000
title: Number Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20220914131211

Values of this type denote a numeric integer value.

=== Allowed values
Must be a sequence of digits (""0""--""9""), optionally prefixed with a ""-"" or a ""+"" character.

=== Match operator
=== Query operator
The match operator is the equals operator, i.e. two values must be numeric equal to match.

All comparisons are done on the given string representation of the number, ""+12"" will be treated as a different number of ""12"".
This includes that ""+12"" is equal to ""12"", therefore both values match.

=== Sorting
Sorting is done by comparing the numeric values.

id: 00001006033500
title: String Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20220914130505

Values of this type are just a sequence of character, but not an empty sequence.

=== Allowed values
All printable characters are allowed.
There must be at least one such character.

=== Match operator
=== Query operator
A value matches a String value, if the first value is part of the String value.
This check is done case-insensitive.
All comparisons are done case-insensitive, i.e. ""hell"" will be the prefix of ""Hello"".

For example, ""hell"" matches ""Hello"".

=== Sorting
To sort two values, the underlying encoding is used to determine which value is less than the other.

Uppercase letters are typically interpreted as less than their corresponding lowercase letters, i.e. ``A < a``.

Comparison is done character-wise by finding the first difference in the respective character sequence.

id: 00001006034000
title: TagSet Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20220218130413
modified: 20220914131048

Values of this type denote a (sorted) set of tags.

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

=== Allowed values
Every tag must must begin with the number sign character (""''#''"", U+0023), followed by at least one printable character.
Tags are separated by space characters.

All characters are mapped to their lower case values.

=== Match operator
=== Query operator
It depends of the first character of a search string how it is matched against a tag set value:

All comparisons are done case-sensitive, i.e. ""#hell"" will not be the prefix of ""#Hello"".
* If the first character of the search string is a number sign character,
  it must exactly match one of the values of a tag.
* In other cases, the search string must be the prefix of at least one tag.

Conceptually, all number sign characters are removed at the beginning of the search string and of all tags.

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

id: 00001006034500
title: Timestamp Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20210511131903
modified: 20220914130919

Values of this type denote a point in time.

=== Allowed values
Must be a sequence of 14 digits (""0""--""9"") (same as an [[Identifier|00001006032000]]), with the restriction that is conforms to the pattern ""YYYYMMDDhhmmss"".

* YYYY is the year,
* MM is the month,
* DD is the day,
* hh is the hour,
* mm is the minute,
* ss is the second.

=== Match operator
=== Query operator
A value matches a timestamp value, if the first value is the prefix of the timestamp value.

All comparisons assume that up to 14 digits are given.
For example, ""202102"" matches ""20210212143200"".

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

If both values are timestamp values, this works well because both have the same length.

id: 00001006035000
title: URL Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20220914130809

Values of this type denote an URL.

=== Allowed values
All characters of an URL / URI are allowed.

=== Match operator
=== Query operator
A value matches a URL value, if the first value is part of the URL value.
This check is done case-insensitive.
All comparisons are done case-insensitive.

For example, ""hell"" matches ""http://example.com/Hello"".
For example, ""hello"" is the suffix of ""http://example.com/Hello"".

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

id: 00001006035500
title: Word Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20210817201304
modified: 20220914130655

Values of this type denote a single word.

=== Allowed values
Must be a non-empty sequence of characters, but without the space character.

All characters are mapped to their lower case values.

=== Match operator
A value matches a word value, if both value are character-wise equal, ignoring upper / lower case.
=== Query operator
All comparisons are done case-insensitive, i.e. ""hell"" will be the prefix of ""Hello"".

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

id: 00001006036000
title: WordSet Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20220724201056
modified: 20220914130725

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 a WordSet value, if the first value is equal to one of the word values in the word set.
=== Query operator
All comparisons are done case-insensitive, i.e. ""hell"" will be the prefix of ""World, Hello"".

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

id: 00001006036500
title: Zettelmarkup Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20220914135405

Values of this type are [[String|00001006033500]] values, interpreted as [[Zettelmarkup|00001007000000]].

=== Allowed values
All printable characters are allowed.
There must be at least one such character.

=== Match operator
A value matches a String value, if the first value is part of the String value.
This check is done case-insensitive.
=== Query operator
Comparison is done similar to the full-text search: both the value to compare and the metadata value are normalized according to Unicode NKFD, ignoring everything except letters and numbers.
Letters are mapped to the corresponding lower-case value.

For example, ""hell"" matches ""Hello"".
For example, ""Brücke"" will be the prefix of ""(Bruckenpfeiler,"".

=== Sorting
To sort two values, the underlying encoding is used to determine which value is less than the other.

Uppercase letters are typically interpreted as less than their corresponding lowercase letters, i.e. ``A < a``.

Comparison is done character-wise by finding the first difference in the respective character sequence.

id: 00001007000000
title: Zettelmarkup
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
created: 20210126175322
modified: 20220810194655
modified: 20220913135505

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.

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.

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.

* [[General principles|00001007010000]]
* [[Basic definitions|00001007020000]]
* [[Block-structured elements|00001007030000]]
* [[Inline-structured element|00001007040000]]
* [[Attributes|00001007050000]]
* [[Search expressions|00001007700000]]
* [[Query expressions|00001007700000]]
* [[Summary of formatting characters|00001007800000]]
* [[Tutorial|00001007900000]]

id: 00001007030400
title: Zettelmarkup: Horizontal Rules / Thematic Break
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
created: 20210126175322
modified: 20220218133651
modified: 20220825185533

To signal a thematic break, you can specify a horizontal rule.
This is done by entering at least three hyphen-minus characters (""''-''"", U+002D) at the first position of a line.
You can add some [[attributes|00001007050000]], although the horizontal rule does not support the default attribute.
Any other character in this line will be ignored
Any other characters in this line will be ignored.

If you do not enter the three hyphen-minus character at the very first position of a line, the are interpreted as [[inline elements|00001007040000]], typically as an ""en-dash" followed by a hyphen-minus.

Example:

```zmk
---

id: 00001007031100
title: Zettelmarkup: Transclusion
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
created: 20220131151022
modified: 20220809144920
modified: 20220913135545

A transclusion allows to include the content of other zettel into the current zettel.

The transclusion specification begins with three consecutive left curly bracket characters (""''{''"", U+007B) at the first position of a line and ends with three consecutive right curly bracket characters (""''}''"", U+007D).
The curly brackets delimit either a [[zettel identifier|00001006050000]] or a searched zettel list.
You can add some [[attributes|00001007050000]], although a transclusion does not support the default attribute.
Any other characters in this line will be ignored.

This leads to two variants of transclusion:
# Transclusion of the content of another zettel into the current zettel.
  This is done if you specify a zettel identifier, and is called ""zettel transclusion"".
# Transclusion of the list of zettel references that satisfy a [[search expression|00001007700000]].
  This is called ""search transclusion"".
# Transclusion of the list of zettel references that satisfy a [[query expression|00001007700000]].
  This is called ""query transclusion"".

The variants are described on separate zettel:
* [[Zettel transclusion|00001007031110]]
* [[Search transclusion|00001007031140]]
* [[Query transclusion|00001007031140]]

id: 00001007031110
title: Zettelmarkup: Zettel Transclusion
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
created: 20220809132350
modified: 20220825190116

A zettel transclusion is specified by the following sequence, starting at the first position in a line: ''{{{zettel-identifier}}}''.

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

This allows, for example, to create a bigger document just by transcluding smaller zettel.

In addition, if a zettel __z__ transcludes a zettel __t__, but the current user is not allowed to view zettel __t__ (but zettel __z__), then the transclusion will not take place.
To the current user, it seems that there was no transclusion in zettel __z__.
This allows to create a zettel with content that seems to be changed, depending on the authorization of the current user.

---
Any [[attributes|00001007050000]] added to the transclusion will set/overwrite the appropriate metadata of the included zettel.
Of course, this applies only to thoes attribtues, which have a valid name for a metadata key.
This allows to control the evaluation of the included zettel, especially for zettel containing a diagram description.

=== See also
[[Inline-mode transclusion|00001007040324]] does not work at the paragraph / block level, but is used for [[inline-structured elements|00001007040000]].

id: 00001007031140
title: Zettelmarkup: Search Transclusion
title: Zettelmarkup: Query Transclusion
role: manual
tags: #manual #search #zettelmarkup #zettelstore
syntax: zmk
created: 20220809132350
modified: 20220811141604
modified: 20220913145104

A search transclusion is specified by the following sequence, starting at the first position in a line: ''{{{search:search-expression}}}''.
The line must literally start with the sequence ''{{{search:''.
Everything after this prefix is interpreted as a [[search expression|00001007700000]].
A query transclusion is specified by the following sequence, starting at the first position in a line: ''{{{query:query-expression}}}''.
The line must literally start with the sequence ''{{{query:''.
Everything after this prefix is interpreted as a [[query expression|00001007700000]].

When evaluated, the search expression is evaluated, leading to a list of [[links|00001007040310]] to zettel, matching the search expression.
When evaluated, the query expression is evaluated, often resulting in a list of [[links|00001007040310]] to zettel, matching the query expression.
Every link references the found zettel, with its title as link text.

This list replaces the search transclusion element.
The result replaces the query transclusion element.

For example, to include the list of all zettel with the [[all-tags|00001006020000#all-tags]] ""#search"", ordered by title specify the following search transclude element:
For example, to include the list of all zettel with the [[all-tags|00001006020000#all-tags]] ""#search"", ordered by title specify the following query transclude element:
```zmk
{{{search:all-tags:#search ORDER title}}}
{{{query:all-tags:#search ORDER title}}}
```
This will result in:
:::zs-example
{{{search:all-tags:#search ORDER title}}}
{{{query:all-tags:#search ORDER title}}}
:::

Please note: if the referenced zettel is changed, all transclusions will also change.

For example, this allows to create a dynamic list of zettel inside a zettel, maybe to provide some introductory text followed by a list of child zettel.

The search will deliver only those zettel, which the current user is allowed to read.
The query will deliver only those zettel, which the current user is allowed to read.

In the above example, the action list is empty.
This leads to the described list of zettel.

The following actions are supported, parameter and aggregate actions:
; ''N'' (or any word that starts with ""''N''"" (parameter)
: The resulting list will be a numbered list.
; ''MINn'' (parameter)
: Emit only those values with at least __n__ aggregated values.
  __n__ must be a positive integer, ''MIN'' must be given in upper-case letters.
; ''MAXn'' (parameter)
: Emit only those values with at most __n__ aggregated values.
  __n__ must be a positive integer, ''MAX'' must be given in upper-case letters.
; ''TITLE'' (parameter)
: All words following ''TITLE'' are joined together to form a title.
  It is used for the ''RSS'' action.
; ''RSS'' (aggregate)
: Transform the zettel list into an [[RSS 2.0|https://www.rssboard.org/rss-specification]]-conformant document.
  The document is embedded into the referencing zettel.
; Any [[metadata key|00001006020000]] of type [[Word|00001006035500]], [[WordSet|00001006036000]], or [[TagSet|00001006034000]] (aggregates)
: Emit an aggregate of the given metadata key.
  The key can be given in any letter case.

```zmk
{{{query:all-tags:#search | all-tags}}}
```
This in a tag cloud of all tags that are used together with the tag #search:
:::zs-example
{{{query:all-tags:#search | all-tags}}}
:::

id: 00001007040000
title: Zettelmarkup: Inline-Structured Elements
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
created: 20210126175322
modified: 20220809171453
modified: 20220913144717

Most characters you type is concerned with inline-structured elements.
The content of a zettel contains is many cases just ordinary text, lightly formatted.
Inline-structured elements allow to format your text and add some helpful links or images.
Sometimes, you want to enter characters that have no representation on your keyboard.

; Text formatting

* Every other character is taken as itself, but without the interpretation of a Zettelmarkup element.
  For example, if you want to enter a ""'']''"" into a [[footnote text|00001007040330]], you should escape it with a backslash.

==== Tag
Any text that begins with a number sign character (""''#''"", U+0023), followed by a non-empty sequence of Unicode letters, Unicode digits, the hyphen-minus character (""''-''"", U+002D), or the low line character (""''_''"", U+005F) is interpreted as an __inline tag__.
They are be considered equivalent to tags in metadata.

**This element is deprecated in version 0.7 and will be removed in version 0.8!**

The use of inline tags is problematic, because:
* The number sign is often used as, well, a number sign, esp. in the English language.
  This introduces unintended tags.
* An inline tag is rendered in HTML as a link.
  However, an inline tag may be the contained in the text part of a [[link element|00001007040310]].
  This will produce a HTML link within a HTML link.
* Similar, an inline tag may be part of the title of a zettel.
  When a zettel list is rendered in HTML, this also produces a HTML link for each zettel, which contains the inline tag HTML link.
* The naming of metadata, [[''tags''|00001006020000#tags]] (names the tags within the metadata section of a zettel), [[''content-tags''|00001006020000#content-tags]] (all inline tags), and [[''all-tags''|00001006020000#all-tags]], is confusing for some users.
  For example, if you follow the link of a tag, it is converted into a [[query|00001007700000]] for the key ''all-tags''.
  A search for ''tags'' will most likely produce different results.

To find all zettel with inline tags, please use the query [[::query:content-tags?::|query:content-tags?]].
There are two, non-exclusive options for migration:
# Move inline tags into the metadata section of a zettel, under the key ''tags''.
  This will allow you to find the zettel via a search for tags in the future.
# Replace the inline tag with a link to a search for that tag: ``#TAG`` could be replace with ``[[#TAG|query:tags:TAG]]``, where ''TAG'' is the placeholder for the actual tag.

==== Entities & more
Sometimes it is not easy to enter special characters.
If you know the Unicode code point of that character, or its name according to the [[HTML standard|https://html.spec.whatwg.org/multipage/named-characters.html]], you can enter it by number or by name.

Regardless which method you use, an entity always begins with an ampersand character (""''&''"", U+0026) and ends with a semicolon character (""'';''"", U+003B).
If you know the HTML name of the character you want to enter, put it between these two character.
Example: ``&`` is rendered as ::&::{=example}.

id: 00001007040310
title: Zettelmarkup: Links
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
created: 20210810155955
modified: 20220808161918
modified: 20220913144754

There are two kinds of links, regardless of links to (internal) other zettel or to (external) material.
Both kinds begin with two consecutive left square bracket characters (""''[''"", U+005B) and ends with two consecutive right square bracket characters (""'']''"", U+005D).

The first form provides some text plus the link specification, delimited by a vertical bar character (""''|''"", U+007C): ``[[text|linkspecification]]``.
The text is a sequence of [[inline elements|00001007040000]].
However, it should not contain links itself.

The second form just provides a link specification between the square brackets.
Its text is derived from the link specification, e.g. by interpreting the link specification as text: ``[[linkspecification]]``.

=== Link specifications
The link specification for another zettel within the same Zettelstore is just the [[zettel identifier|00001006050000]].
To reference some content within a zettel, you can append a number sign character (""''#''"", U+0023) and the name of the mark to the zettel identifier.
The resulting reference is called ""zettel reference"".

If the link specification begins with the string ''search:'', the text following this string will be interpreted as a [[search expression|00001007700000]].
The resulting reference is called ""search reference"".
When this type of references is rendered, it will reference a list of all zettel that fulfills the search expression.
If the link specification begins with the string ''query:'', the text following this string will be interpreted as a [[query expression|00001007700000]].
The resulting reference is called ""query reference"".
When this type of references is rendered, it will typically reference a list of all zettel that fulfills the query expression.

A link specification starting with one slash character (""''/''"", U+002F), or one or two full stop characters (""''.''"", U+002E) followed by a slash character,
will be interpreted as a local reference, called ""hosted reference"".
Such references will be interpreted relative to the web server hosting the Zettelstore.

If a link specification begins with two slash characters, it will be interpreted relative to the value of [[''url-prefix''|00001004010000#url-prefix]].

To specify some material outside the Zettelstore, just use an normal Uniform Resource Identifier (URI) as defined by [[RFC\ 3986|https://tools.ietf.org/html/rfc3986]].

=== Other topics
If the link references another zettel, and this zettel is not readable for the current user, because of a missing access rights, then only the associated text is presented.

id: 00001007050100
title: Zettelmarkup: Supported Attribute Values for Natural Languages
role: manual
tags: #manual #reference #zettelmarkup #zettelstore
syntax: zmk
role: manual
created: 20210126175322
modified: 20220827182130

With an [[attribute|00001007050000]] it is possible to specify the natural language of a text region.
This is important, if you want to render your markup into an environment, where this is significant.
HTML is such an environment.

To specify the language within an attribute, you must use the key ''lang''.
The language itself is specified according to the language definition of [[RFC-5646|https://tools.ietf.org/html/rfc5646]].

Examples:
* ``{lang=en}`` for the english language
* ``{lang=en-us}`` for the english dialect spoken in the United States of America
* ``{lang=de}`` for the german language
* ``{lang=de-at}`` for the german language dialect spoken in Austria
* ``{lang=de-de}`` for the german language dialect spoken in Germany

The actual [[typographic quotations marks|00001007040100]] (``""...""``) are derived from the current language.
The language of a zettel (meta key ''lang'') or of the whole Zettelstore (''default-lang'' of the [[configuration zettel|00001004020000#default-lang]]) can be overwritten by an attribute: ``""...""{lang=fr}``{=zmk}.
The language of a zettel (meta key ''lang'') can be overwritten by an attribute: ``""...""{lang=fr}``{=zmk}.
Currently, Zettelstore supports the following primary languages:

* ''de''
* ''en''
* ''fr''

These are used, even if a dialect was specified.

id: 00001007700000
title: Search expression
title: Query expression
role: manual
tags: #manual #search #zettelstore
syntax: zmk
created: 20220805150154
modified: 20220810164112
modified: 20220913135434

A search expression allows you to search for specific zettel.
You may select zettel based on a full-text search, based on specifc metadata values, or both.
A query expression allows you to search for specific zettel and to perform some actions on them.
You may select zettel based on a full-text search, based on specific metadata values, or both.

A query expression consists of a __search expression__ and of an optional __action list__.
Both are separated by a vertical bar character (""''|''"", U+007C).

A query expression follows a [[formal syntax|00001007780000]].

=== Search expression

In its simplest form, a search expression just contains a string to be search for with the help of a full-text search.
For example, the string ''syntax'' will search for all zettel containing the word ""syntax"".

If you want to search for all zettel with a title containing the word ""syntax"", you must specify ''title:syntax''.
""title"" names the [[metadata key|00001006010000]], in this case the [[supported metadata key ""title""|00001006020000#title]].
The colon character (""'':''"") is a [[search operator|00001007705000]], in this example to specify a match.
""syntax"" is the [[search value|00001007706000]] that must match to the value of the given metadata key, here ""title"".

A search expression may contain more than one search term, such as ''title:syntax''.
Search terms must be separated by one or more space characters, for example ''title:syntax title:search''.
All terms of a select expression must be true so that a zettel is selected.

* [[Search terms|00001007702000]]
* [[Search operator|00001007705000]]
* [[Search value|00001007706000]]

Here are [[some examples|00001007790000]] of search expressions, which can be used to manage a Zettelstore:
{{{00001007790000}}}
A search expression follows a [[formal syntax|00001007780000]].

=== Action List

With a search expression, a list of zettel is selected.
Actions allow to modify this list to a certain degree.
Here are some examples of search expressions, which can be used to manage a Zettelstore:
{{{00001007790000}}}

Which actions are allowed depends on the context.
However, actions are further separated into __parameter action__ and __aggregate actions__.
A parameter action just sets a parameter for an aggregate action.
An aggregate action transforms the list of selected zettel into a different, aggregate form.
Only the first aggregate form is executed, following aggregate actions are ignored.

In most contexts, valid actions include the name of metadata keys, at least of type [[Word|00001006035500]], [[WordSet|00001006036000]], or [[TagSet|00001006034000]].

id: 00001007702000
title: Search term
role: manual
tags: #manual #search #zettelstore
syntax: zmk
modified: 20220808130055
modified: 20220821163727

A search term allows you to specify one search restriction.
The result [[search expression|00001007700000]], which contains more than one search term, will be the applications of all restrictions.

A search term can be one of the following:
A search term can be one of the following (the first three term are collectively called __search literals__):
* A metadata-based search, by specifying the name of a [[metadata key|00001006010000]], followed by a [[search operator|00001007705000]], followed by an optional [[search value|00001007706000]].

  All zettel containing the given metadata key with a allowed value (depending on the search operator) are selected.

  If no search value is given, then all zettel containing the given metadata key are selected (or ignored, for a negated search operator).
* An optional [[search operator|00001007705000]], followed by a [[search value|00001007706000]].

  This specifies a full-text search for the given search value.

  **Note:** the search value will be normalized according to Unicode NKFD, ignoring everything except letters and numbers.
  Therefore, the following search expression are essentially the same: ''"search syntax"'' and ''search syntax''.
  The first is a search expression with one search value, which is normalized to two strings to be searched for.
  The second is a search expression containing two search values, giving two string to be searched for.
* A metadata key followed by ""''?''"" or ""''!?''"".
* The string ''NEGATE'' will negate (sic!) the behavior of the whole search expression.
  If it occurs multiple times, the negation will be negated.

  Is true, if zettel metadata contains / does not contain the given key.
* The string ''OR'' signals that following search literals may occur alternatively in the result.

  Since search literals may be negated, it is possible to form any boolean search expression.
  Any search expression will be in a [[disjunctive normal form|https://en.wikipedia.org/wiki/Disjunctive_normal_form]].

  It has no effect on the following search terms initiated with a special uppercase word.
* The string ''ORDER'', followed by a non-empty sequence of spaces and the name of a metadata key, will specify an ordering of the result list.
  If you include the string ''REVERSE'' after ''ORDER'' but before the metadata key, the ordering will be reversed.

  Example: ''ORDER published'' will order the resulting list based on the publishing data, while ''ORDER REVERSED published'' will return a reversed result order.

  An explicit order field will take precedence over the random order described below.
  Currently, only the first term specifying the order of the resulting list will be used.
  Other ordering terms will be ignored.

  If no random order is effective, a ``ORDER REVERSE id`` will be added.
  This makes the sort stable.

  Example: ``ORDER created`` will be interpreted as ``ORDER created ORDER REVERSE id``.
  An explicit order field will take precedence over the random order described below.

  Any ordering by zettel identifier will make following order terms to be ignored.

  Example: ``ORDER id ORDER created`` will be interpreted as ``ORDER id``.
* The string ''RANDOM'' will provide a random order of the resulting list.

  Currently, only the first term specifying the order of the resulting list will be used.
  Other ordering terms will be ignored.

  A random order specification will be ignored, if there is an explicit ordering given.

  Example: ''RANDOM ORDER published'' will be interpreted as ''ORDER published''.

* The string ''OFFSET'', followed by a non-empty sequence of spaces and a number greater zero (called ""N"").

  This will ignore the first N elements of the result list, based on the specified sort order.
  A zero value of N will produce the same result as if nothing was specified.
  If specified multiple times, the higher value takes precedence.

  Example: ''OFFSET 4 OFFSET 8'' will be interpreted as ''OFFSET 8''.

* The string ''LIMIT'', followed by a non-empty sequence of spaces and a number greater zero (called ""N"").

  This will limit the result list to the first N elements, based on the specified sort order.
  A zero value of N will produce the same result as if nothing was specified.
  If specified multiple times, the lower value takes precedence.

  Example: ''LIMIT 4 LIMIT 8'' will be interpreted as ''LIMIT 4''.

id: 00001007705000
title: Search operator
role: manual
tags: #manual #search #zettelstore
syntax: zmk
modified: 20220811141050
modified: 20220819194709

A search operator specifies how the comparison of a search value and a zettel should be executed.
Every comparison is done case-insensitive, treating all uppercase letters the same as lowercase letters.

The following are allowed search operator characters:
* The exclamation mark character (""!"", U+0021) negates the meaning
* The tilde character (""''~''"", U+007E) compares on containment (""contains operator"")
* The tilde character (""''~''"", U+007E) compares on matching (""match operator"")
* The greater-than sign character (""''>''"", U+003E) matches if there is some prefix (""prefix operator"")
* The less-than sign character (""''<''"", U+003C) compares a suffix relationship (""suffix operator"")
* The colon character (""'':''"", U+003A) specifies the __default comparison__, i.e. one of the previous comparisons.

* The colon character (""'':''"", U+003A) compares on equal words (""has operator"")
* The question mark (""''?''"", U+003F) checks for an existing metadata key (""exist operator"")
  **Please note:** this operator will be changed in version 0.7.0.
  It was included to allow the transition of the previous mechanism into search expressions.

  With version 0.7.0, this operator will take the role of the ''=''-operator.
* The equal sign character (""''=''"", U+003D) compares on equal words (""equal operator"")

  **Please note:** this operator will be removed in version 0.7.0.
  It was included to allow the transition of the previous mechanism into search expressions.

Since the exclamation mark character can be combined with the other, there are 12 possible combinations:
# ""''!''"": is an abbreviation of the ""''!:''"" operator.
Since the exclamation mark character can be combined with the other, there are 10 possible combinations:
# ""''!''"": is an abbreviation of the ""''!~''"" operator.
# ""'':''"": depending on the [[metadata key type|00001006030000]] one of the other operators is chosen.
  For example, a [[numeric key type|00001006033000]] will execute the equals operator, while for a [[string type|00001006033500]] a contains operator will be executed.

  With version 0.7.0 its meaning will be changed to that of the ''='' operator.
# ""''!:''"": similar to the ""match operator"" above, the appropriate negated search operator will be chosen, depending on the metadata key type

  With version 0.7.0 its meaning will be changed to that of the ''!='' operator.
# ""''~''"": is successful if the search value is contained in the value to be compared.
# ""''!~''"": is successful if the search value is not contained in the value to be compared.
# ""''=''"": is successful if the search value is equal to one word of the value to be compared.
# ""''!=''"": is successful if the search value is not equal to any word of the value to be compared.
# ""''~''"": is successful if the search value matched the value to be compared.
# ""''!~''"": is successful if the search value does not match the value to be compared.
# ""'':''"": is successful if the search value is equal to one word of the value to be compared.
# ""''!:''"": is successful if the search value is not equal to any word of the value to be compared.
# ""''>''"": is successful if the search value is a prefix of the value to be compared.
# ""''!>''"": is successful if the search value is not a prefix of the value to be compared.
# ""''<''"": is successful if the search value is a suffix of the value to be compared.
# ""''!<''"": is successful if the search value is not a suffix of the value to be compared.
# ""''?''"": is successful if the metadata contains the given key.
# ""''!?''"": is successful if the metadata does not contain the given key.
# ""''''"": a missing search operator can only occur for a full-text search.
  It is equal to the ""''~''"" operator.

id: 00001007780000
title: Forma syntax of search expressions
title: Formal syntax of query expressions
role: manual
tags: #manual #reference #search #zettelstore
syntax: zmk
created: 20220810144539
modified: 20220811141423
modified: 20220913134024

```
QueryExpression  := SearchExpression ActionExpression?
SearchExpression := SearchTerm (SPACE+ SearchTerm)*.
SearchTerm       := "NEGATE"
SearchTerm       := SearchOperator? SearchValue
                  | SearchOperator? SearchValue
                  | SearchKey SearchOperator SearchValue?
                  | SearchKey ExistOperator
                  | "OR"
                  | "RANDOM"
                  | "ORDER" SPACE+ ("REVERSE" SPACE+)? SearchKey
                  | "OFFSET" SPACE+ PosInt
                  | "LIMIT" SPACE+ PosInt.
SearchValue      := NO-SPACE (NO-SPACE)*.
SearchValue      := Word.
SearchKey        := MetadataKey.
SearchOperator   := '!'
                 | ('!')? '='                ← removed in version 0.7.0
                 | ('!')? (':' | '<' | '>').
                  | ('!')? ('~' | ':' | '<' | '>').
ExistOperator    := '?'
                  | '!' '?'.
PosInt           := '0'
                  | ('1' .. '9') DIGIT*.
ActionExpression := '|' (Word (SPACE+ Word)*)?
Word             := NO-SPACE NO-SPACE*
```

id: 00001007790000
title: Useful search expressions
title: Useful query expressions
role: manual
tags: #example #manual #search #zettelstore
syntax: zmk
created: 20220810144539
modified: 20220811141224
modified: 20220913144959

|= Search Expression |= Meaning
| [[search:role:configuration]] | Zettel that contains some configuration data for the Zettelstore
| [[search:ORDER REVERSE id LIMIT 40]] | 40 recently created zettel
| [[search:ORDER REVERSE published LIMIT 40]] | 40 recently updated zettel
| [[search:RANDOM LIMIT 40]] | 40 random zettel
| [[search:dead:]] | Zettel with invalid / dead links
| [[search:backward!: precursor!:]] | Zettel that are not referenced by other zettel
| [[search:all-tags!:]] | Zettel without any tags
| [[search:tags!:]] | Zettel without tags that are defined within metadata
| [[search:content-tags:]] | Zettel with tags within content
|= Query Expression |= Meaning
| [[query:role:configuration]] | Zettel that contains some configuration data for the Zettelstore
| [[query:ORDER REVERSE created LIMIT 40]] | 40 recently created zettel
| [[query:ORDER REVERSE published LIMIT 40]] | 40 recently updated zettel
| [[query:RANDOM LIMIT 40]] | 40 random zettel
| [[query:dead?]] | Zettel with invalid / dead links
| [[query:backward!? precursor!?]] | Zettel that are not referenced by other zettel
| [[query:all-tags!?]] | Zettel without any tags
| [[query:tags!?]] | Zettel without tags that are defined within metadata
| [[query:content-tags?]] | Zettel with tags within content

id: 00001008000000
title: Other Markup Languages
role: manual
tags: #manual #zettelstore
syntax: zmk
created: 20210126175300
modified: 20220627192329
modified: 20220824114649

[[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

; [!mustache|''mustache'']
: A [[Mustache template|https://mustache.github.io/]], used when rendering a zettel as HTML for the [[web user interface|00001014000000]].
; [!none|''none'']
: Only the metadata of a zettel is ""parsed"".
  Useful for displaying the full metadata.
  The [[runtime configuration zettel|00000000000100]] uses this syntax.
  The zettel content is ignored.
; [!pikchr]''pikchr''
: A [[PIC|https://en.wikipedia.org/wiki/Pic_language]]-like [[markup language for diagrams|https://pikchr.org/]].
; [!svg|''svg'']
: A [[Scalable Vector Graphics|https://www.w3.org/TR/SVG2/]].
: [[Scalable Vector Graphics|https://www.w3.org/TR/SVG2/]].
; [!text|''text''], [!plain|''plain''], [!txt|''txt'']
: Just plain text that must not be interpreted further.
: 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: 00001010070200
title: Visibility rules for zettel
role: manual
tags: #authorization #configuration #manual #security #zettelstore
syntax: zmk
created: 20210126175322
modified: 20220808152359
modified: 20220913144845

For every zettel you can specify under which condition the zettel is visible to others.
This is controlled with the metadata key [[''visibility''|00001006020000#visibility]].
The following values are supported:

; [!public|""public""]
: The zettel is visible to everybody, even if the user is not authenticated.

  This is for zettel with sensitive content, e.g. the [[configuration zettel|00001004020000]] or the various zettel that contains the templates for rendering zettel in HTML.
; [!expert|""expert""]
: Only the owner of the Zettelstore can access the zettel, if runtime configuration [[''expert-mode''|00001004020000#expert-mode]] is set to a [[boolean true value|00001006030500]].

  This is for zettel with sensitive content that might irritate the owner.
  Computed zettel with internal runtime information are examples for such a zettel.

When you install a Zettelstore, only [[some zettel|//h?visibility=public]] have visibility ""public"".
When you install a Zettelstore, only [[some zettel|query:visibility:public]] have visibility ""public"".
One is the zettel that contains [[CSS|00000000020001]] for displaying the [[web user interface|00001014000000]].
This is to ensure that the web interface looks nice even for not authenticated users.
Another is the zettel containing the Zettelstore [[license|00000000000004]].
The [[default image|00000000040001]], used if an image reference is invalid, is also public visible.

Please note: if [[authentication is not enabled|00001010040100]], every user has the same rights as the owner of a Zettelstore.
This is also true, if the Zettelstore runs additionally in [[read-only mode|00001004010000#read-only-mode]].
In this case, the [[runtime configuration zettel|00001004020000]] is shown (its visibility is ""owner"").
The [[startup configuration|00001004010000]] is not shown, because the associated computed zettel with identifier ''00000000000096'' is stored with the visibility ""expert"".
If you want to show such a zettel, you must set ''expert-mode'' to true.

=== Examples
Similar to the [[API|00001012051810]], you can easily create a zettel list based on the ''visibility'' metadata key:
Similar to the [[API|00001012051840]], you can easily create a zettel list based on the ''visibility'' metadata key:

| public  | [[search:visibility:public]]
| login   | [[search:visibility:login]]
| creator | [[search:visibility:creator]]
| owner   | [[search:visibility:owner]]
| expert  | [[search:visibility:expert]][^Only if [[''expert-mode''|00001004020000#expert-mode]] is enabled, this list will show some zettel.]
| public  | [[query:visibility:public]]
| login   | [[query:visibility:login]]
| creator | [[query:visibility:creator]]
| owner   | [[query:visibility:owner]]
| expert  | [[query:visibility:expert]][^Only if [[''expert-mode''|00001004020000#expert-mode]] is enabled, this list will show some zettel.]

id: 00001012000000
title: API
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210126175322
modified: 20220805144406
modified: 20220913141632

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.

There is an [[overview zettel|00001012920000]] that shows the structure of the endpoints used by the API and gives an indication about its use.

=== Authentication
If [[authentication is enabled|00001010040100]], most API calls must include an [[access token|00001010040700]] that proves the identity of the caller.
* [[Authenticate an user|00001012050200]] to obtain an access token
* [[Renew an access token|00001012050400]] without costly re-authentication
* [[Provide an access token|00001012050600]] when doing an API call

=== Zettel lists
* [[List metadata of all zettel|00001012051200]]
* [[Shape the list of zettel metadata|00001012051800]]
** [[Selection of zettel|00001012051810]]
** [[Limit the list length|00001012051830]]
** [[Search expressions|00001012051840]] (includes content search)
** [[Query expressions|00001012051840]] (includes content search)
** [[Sort the list of zettel metadata|00001012052000]]
* [[Map metadata values to lists of zettel identifier|00001012052400]]
* [[Query the list of all zettel|00001012051400]]

=== 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: 00001012051200
title: API: List metadata of all zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210126175322
modified: 20220201180649
modified: 20220913151852

To list the metadata of all zettel just send a HTTP GET request to the [[endpoint|00001012920000]] ''/j''[^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
{"query":"","list":[{"id":"00001012051200","meta":{"title":"API: Renew an access token","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"},"rights":62},{"id":"00001012050600","meta":{"title":"API: Provide an access token","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"},"rights":62},{"id":"00001012050400","meta":{"title":"API: Renew an access token","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"},"rights":62},{"id":"00001012050200","meta":{"title":"API: Authenticate a client","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"},"rights":62},{"id":"00001012000000","meta":{"title":"API","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"},"rights":62}]}
```

The JSON object contains a key ''"list"'' where its value is a list of zettel JSON objects.
These zettel JSON objects themselves contains the keys ''"id"'' (value is a string containing the [[zettel identifier|00001006050000]]), ''"meta"'' (value as a JSON object), and ''"rights"'' (encodes the [[access rights|00001012921200]] for the given zettel).
The value of key ''"meta"'' effectively contains all metadata of the identified zettel, where metadata keys are encoded as JSON object keys and metadata values encoded as JSON strings.

Additionally, the JSON object contains a key ''"query"'' with a string value.
It will contain a textual description of the underlying query if you [[select only some zettel|00001012051810]].
Without a selection, the value is the empty string.
Additionally, the JSON object contains the keys ''"query"'' and ''"human"'' with a string value.
Both will contain a textual description of the underlying query if you select only some zettel with a [[query expression|00001012051840]].
Without a selection, the values are the empty string.
''"query"'' returns the normalized query expression itself, while ''"human"'' is the normalized query expression to be read by humans.

If you reformat the JSON output from the ''GET /j'' call, you'll see its structure better:

```json
{
  "query": "",
  "human": "",
  "list": [
    {
      "id": "00001012051200",
      "meta": {
        "title": "API: List for all zettel some data",
        "tags": "#api #manual #zettelstore",
        "syntax": "zmk",

id: 00001012051400
title: API: Query the list of all zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20220912111111
modified: 20220913150204

The [[endpoint|00001012920000]] ''/q'' allows to query the list of all zettel.

A [[query|00001007700000]] is an optional [[search expression|00001007700000#search-expression]], together with an optional [[list of actions|00001007700000#action-list]] (described below).
An empty search expression will select all zettel.
An empty list of action will return nothing.
It is an error, if both are empty.

Search expression and action list are separated by a vertical bar character (""''|''"", U+007C), and must be given with the query parameter ''q''.

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

```sh
# curl http://127.0.0.1:23123/q?q=|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 ''/q?q=|tags''.
If successful, the output is a JSON object:

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

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.

If you want only those tags that occur at least 100 times, use the endpoint ''/q?q=|MIN100+tags''.
You see from this that actions are separated by space characters.

There are two types of actions: parameters and aggregates.
The following actions are supported:
; ''MINn'' (parameter)
: Emit only those values with at least __n__ aggregated values.
  __n__ must be a positive integer, ''MIN'' must be given in upper-case letters.
; ''MAXn'' (parameter)
: Emit only those values with at most __n__ aggregated values.
  __n__ must be a positive integer, ''MAX'' must be given in upper-case letters.
; Any [[metadata key|00001006020000]] of type [[Word|00001006035500]], [[WordSet|00001006036000]], or [[TagSet|00001006034000]] (aggregates)
: Emit an aggregate of the given metadata key.
  The key can be given in any letter case.

Only the first aggregate action will be executed.

=== HTTP Status codes
; ''200''
: Query was successful.
; ''204''
: Query was successful, but results in no content.
  Most likely, you specified no appropriate aggregator.
; ''400''
: Request was not valid. 
  There are several reasons for this.
  Maybe the access bearer token was not valid, or you forgot to specify a valid query.

id: 00001012051800
title: API: Shape the list of zettel metadata
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20220805144809

In most cases, it is not essential to list __all__ zettel.
Typically, you are interested only in a subset of the zettel maintained by your Zettelstore.
This is done by adding some query parameters to the general ''GET /j'' request.

* [[Select|00001012051810]] just some zettel, based on metadata.
* Only a specific amount of zettel will be selected by specifying [[a length and/or an offset|00001012051830]].
* [[Specifying a search expression|00001012051840]], e.g. searching for zettel content and/or metadata, is another way of selecting some zettel.
* The resulting list can be [[sorted|00001012052000]] according to various criteria.

id: 00001012051810
title: API: Select zettel based on their metadata
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20220811141840

Every query parameter that does __not__ begin with the low line character (""_"", U+005F) is treated as the name of a [[metadata|00001006010000]] key.
According to the [[type|00001006030000]] of a metadata key, zettel are possibly selected.
All [[supported|00001006020000]] metadata keys have a well-defined type.
User-defined keys have the type ''e'' (string, possibly empty).

For example, if you want to retrieve all zettel that contain the string ""API"" in its title, your request will be:
```sh
# curl 'http://127.0.0.1:23123/j?title=API'
{"query":"title MATCH API","list":[{"id":"00001012921000","meta":{"title":"API: JSON structure of an access token","tags":"#api #manual #reference #zettelstore","syntax":"zmk","role":"manual"}},{"id":"00001012920500","meta":{"title":"Formats available by the API","tags":"#api #manual #reference #zettelstore","syntax":"zmk","role":"manual"}},{"id":"00001012920000","meta":{"title":"Endpoints used by the API","tags":"#api #manual #reference #zettelstore","syntax":"zmk","role":"manual"}}, ...
```

However, if you want all zettel that does not match a given value, you must prefix the value with the exclamation mark character (""!"", U+0021).
For example, if you want to retrieve all zettel that do not contain the string ""API"" in their title, your request will be:
```sh
# curl 'http://127.0.0.1:23123/j?title=!API'
{"query":"title NOT MATCH API","list":[{"id":"00010000000000","meta":{"back":"00001003000000 00001005090000","backward":"00001003000000 00001005090000","copyright":"(c) 2020-2021 by Detlef Stern <ds@zettelstore.de>","forward":"00000000000001 00000000000003 00000000000096 00000000000100","lang":"en","license":"EUPL-1.2-or-later","role":"zettel","syntax":"zmk","title":"Home"}},{"id":"00001014000000","meta":{"back":"00001000000000 00001004020000 00001012920510","backward":"00001000000000 00001004020000 00001012000000 00001012920510","copyright":"(c) 2020-2021 by Detlef Stern <ds@zettelstore.de>","forward":"00001012000000","lang":"en","license":"EUPL-1.2-or-later","published":"00001014000000","role":"manual","syntax":"zmk","tags":"#manual #webui #zettelstore","title":"Web user interface"}},
...
```

In both cases, an implicit precondition is that the zettel must contain the given metadata key.
For a metadata key like [[''title''|00001006020000#title]], which has a default value, this precondition should always be true.
But the situation is different for a key like [[''url''|00001006020000#url]].
Both ``curl 'http://localhost:23123/j?url='`` and ``curl 'http://localhost:23123/j?url=!'`` may result in an empty list.

The empty query parameter values matches all zettel that contain the given metadata key.
Similar, if you specify just the exclamation mark character as a query parameter value, only those zettel match that does not contain the given metadata key.
This is in contrast to above rule that the metadata value must exist before a match is done.
For example ``curl 'http://localhost:23123/j?back=!&backward='`` returns all zettel that are reachable via other zettel, but also references these zettel.

As stated above, the exact rule for comparison depends on the [[type|00001006030000]] of the specified metadata key.
By using a [[simple search syntax|00001012051890]], you are able to specify other comparison operations.[^One is the already mentioned exclamation mark character.]

Above example shows that all sub-expressions of a select specification must be true so that no zettel is rejected from the final list.

If you specify the query parameter ''_negate'', either with or without a value, the whole selection will be negated.
Because of the precondition described above, ``curl 'http://127.0.0.1:23123/j?url=!com'`` and ``curl 'http://127.0.0.1:23123/j?url=com&_negate'`` may produce different lists.
The first query produces a zettel list, where each zettel does have a ''url'' metadata value, which does not contain the characters ""com"".
The second query produces a zettel list, that excludes any zettel containing a ''url'' metadata value that contains the characters ""com""; this also includes all zettel that do not contain the metadata key ''url''.

Alternatively, you also can use the [[endpoint|00001012920000]] ''/z'' for a simpler result format.
The first example translates to:
```sh
# curl 'http://127.0.0.1:23123/z?title=API'
00001012921000 API: JSON structure of an access token
00001012920500 Formats available by the API
00001012920000 Endpoints used by the API
...
```
=== Deprecation
Comparisons via URL query parameter are deprecated since version 0.6.0.
They will be removed in version 0.7.0

id: 00001012051830
title: API: Shape the list of zettel metadata by limiting its length
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20211004124642

=== Limit
By using the query parameter ""''_limit''"", which must have an integer value, you specifying an upper limit of list elements:
```sh
# curl 'http://127.0.0.1:23123/j?title=API&_sort=id&_limit=2'
{"query":"title MATCH API LIMIT 2","list":[{"id":"00001012000000","meta":{"all-tags":"#api #manual #zettelstore","back":"00001000000000 00001004020000","backward":"00001000000000 00001004020000 00001012053200 00001012054000 00001014000000","box-number":"1","forward":"00001010040100 00001010040700 00001012050200 00001012050400 00001012050600 00001012051200 00001012051800 00001012051810 00001012051830 00001012051840 00001012052000 00001012052200 00001012052400 00001012052600 00001012053200 00001012053300 00001012053500 00001012053600 00001012053700 00001012053800 00001012054000 00001012054200 00001012054400 00001012054600 00001012920000 00001014000000","modified":"20210817160844","published":"20210817160844","role":"manual","syntax":"zmk","tags":"#api #manual #zettelstore","title":"API"}},{"id":"00001012050200","meta":{"all-tags":"#api #manual #zettelstore","back":"00001012000000 00001012050400 00001012050600 00001012051200 00001012053400 00001012053500 00001012053600","backward":"00001010040700 00001012000000 00001012050400 00001012050600 00001012051200 00001012053400 00001012053500 00001012053600 00001012920000 00001012921000","box-number":"1","forward":"00001004010000 00001010040200 00001010040700 00001012920000 00001012921000","modified":"20210726123709","published":"20210726123709","role":"manual","syntax":"zmk","tags":"#api #manual #zettelstore","title":"API: Authenticate a client"}}]}
```

```sh
# curl 'http://127.0.0.1:23123/z?title=API&_sort=id&_limit=2'
00001012000000 API
00001012050200 API: Authenticate a client
```

=== Offset
The query parameter ""''_offset''"" allows to list not only the first elements, but to begin at a specific element:
```sh
# curl 'http://127.0.0.1:23123/j?title=API&_sort=id&_limit=2&_offset=1'
{"query":"title MATCH API OFFSET 1 LIMIT 2","list":[{"id":"00001012050200","meta":{"all-tags":"#api #manual #zettelstore","back":"00001012000000 00001012050400 00001012050600 00001012051200 00001012053400 00001012053500 00001012053600","backward":"00001010040700 00001012000000 00001012050400 00001012050600 00001012051200 00001012053400 00001012053500 00001012053600 00001012920000 00001012921000","box-number":"1","forward":"00001004010000 00001010040200 00001010040700 00001012920000 00001012921000","modified":"20210726123709","published":"20210726123709","role":"manual","syntax":"zmk","tags":"#api #manual #zettelstore","title":"API: Authenticate a client"}},{"id":"00001012050400","meta":{"all-tags":"#api #manual #zettelstore","back":"00001010040700 00001012000000","backward":"00001010040700 00001012000000 00001012920000 00001012921000","box-number":"1","forward":"00001010040100 00001012050200 00001012920000 00001012921000","modified":"20210726123745","published":"20210726123745","role":"manual","syntax":"zmk","tags":"#api #manual #zettelstore","title":"API: Renew an access token"}}]}
```

```sh
# curl 'http://127.0.0.1:23123/z?title=API&_sort=id&_limit=2&_offset=1'
00001012050200 API: Authenticate a client
00001012050400 API: Renew an access token
```

id: 00001012051840
title: API: Shape the list of zettel metadata by specifying a search expression
title: API: Shape the list of zettel metadata by specifying a query expression
role: manual
tags: #api #manual #search #zettelstore
syntax: zmk
created: 20210709143714
modified: 20220805165619
modified: 20220913150355

The query parameter ""''_s''"" allows you to specify [[search expressions|00001007700000]] for a full-text search of all zettel content and/or restricting the search according to specific metadata.
The query parameter ""''q''"" allows you to specify [[query expressions|00001007700000]] for a full-text search of all zettel content and/or restricting the search according to specific metadata.

You are allowed to specify this query parameter more than once, as well as the other query parameters.
All results will be intersected, i.e. a zettel will be included into the list if all of the provided values match.

This parameter loosely resembles the search form of the [[web user interface|00001014000000]].

For example, if you want to retrieve all zettel that contain the string ""API"" in its title, your request will be:
```sh
# curl 'http://127.0.0.1:23123/j?q=title%3AAPI'
{"query":"title MATCH API","list":[{"id":"00001012921000","meta":{"title":"API: JSON structure of an access token","tags":"#api #manual #reference #zettelstore","syntax":"zmk","role":"manual"}},{"id":"00001012920500","meta":{"title":"Formats available by the API","tags":"#api #manual #reference #zettelstore","syntax":"zmk","role":"manual"}},{"id":"00001012920000","meta":{"title":"Endpoints used by the API","tags":"#api #manual #reference #zettelstore","syntax":"zmk","role":"manual"}}, ...
```

However, if you want all zettel that does not match a given value, you must prefix the value with the exclamation mark character (""!"", U+0021).
For example, if you want to retrieve all zettel that do not contain the string ""API"" in their title, your request will be:
```sh
# curl 'http://127.0.0.1:23123/j?q=title!%3AAPI'
{"query":"title NOT MATCH API","list":[{"id":"00010000000000","meta":{"back":"00001003000000 00001005090000","backward":"00001003000000 00001005090000","copyright":"(c) 2020-2021 by Detlef Stern <ds@zettelstore.de>","forward":"00000000000001 00000000000003 00000000000096 00000000000100","lang":"en","license":"EUPL-1.2-or-later","role":"zettel","syntax":"zmk","title":"Home"}},{"id":"00001014000000","meta":{"back":"00001000000000 00001004020000 00001012920510","backward":"00001000000000 00001004020000 00001012000000 00001012920510","copyright":"(c) 2020-2021 by Detlef Stern <ds@zettelstore.de>","forward":"00001012000000","lang":"en","license":"EUPL-1.2-or-later","published":"00001014000000","role":"manual","syntax":"zmk","tags":"#manual #webui #zettelstore","title":"Web user interface"}},
...
```

In both cases, an implicit precondition is that the zettel must contain the given metadata key.
For a metadata key like [[''title''|00001006020000#title]], which has a default value, this precondition should always be true.
But the situation is different for a key like [[''url''|00001006020000#url]].
Both ``curl 'http://localhost:23123/j?q=url%3A'`` and ``curl 'http://localhost:23123/j?q=url%3A!'`` may result in an empty list.

Alternatively, you also can use the [[endpoint|00001012920000]] ''/z'' for a simpler result format.
The first example translates to:
```sh
# curl 'http://127.0.0.1:23123/z?q=title%3AAPI'
00001012921000 API: JSON structure of an access token
00001012920500 Formats available by the API
00001012920000 Endpoints used by the API
...
```

id: 00001012051890
title: API: Comparison syntax (simple)
role: manual
tags: #api #manual #search #zettelstore
syntax: zmk
modified: 20220811141804

By using a simple syntax for comparing metadata values, you can modify the default comparison.
Note, this syntax is intend-fully similar to the syntax of the more general [[search operators|00001007705000]], which are part of [[search expressions|00001007700000]].

If the search string starts with the exclamation mark character (""!"", U+0021), it will be removed and the query matches all values that **do not match** the search string.

In the next step, the first character of the search string will be inspected.
If it contains one of the characters ""'':''"", ""''=''"", ""''>''"", ""''<''"", or ""''~''"", this will modify how the search will be performed.
The character will be removed from the start of the search string.

For example, assume the search string is ""def"":

; The colon character (""'':''"", U+003A) (or none of these characters)
: This is the __default__ comparison.
  The comparison chosen depends on the [[metadata key type|00001006030000]].

  It you omit the the comparison character, the default comparison is also used.
; The tilde character (""''~''"", U+007E)
: The inspected text[^Either all words of the zettel content and/or some metadata values] contains the search string.
  ""def"", ""defghi"", and ""abcdefghi"" are matching the search string.
; The equal sign character (""''=''"", U+003D)
: The inspected text must contain a word that is equal to the search string.
  Only the word ""def"" matches the search string.
; The greater-than sign character (""''>''"", U+003E)
: The inspected text must contain a word with the search string as a prefix.
  A word like ""def"" or ""defghi"" matches the search string.
; The less-than sign character (""''<''"", U+003C)
: The inspected text must contain a word with the search string as a suffix.
  A word like ""def"" or ""abcdef"" matches the search string.

If you want to include an initial ""''!''"" into the search string, you must prefix that with the escape character ""''\\''"".
For example ""\\!abc"" will search for the string ""!abc"".
A similar rule applies to the characters that specify the way how the search will be done.
For example, ""!\\=abc"" will search for content that does not contains the string ""=abc"".

=== Deprecation
Comparisons via URL query parameter are deprecated since version 0.6.0.
They will be removed in version 0.7.0

id: 00001012052000
title: API: Sort the list of zettel metadata
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20220218131937

If not specified, the list of zettel is sorted descending by the value of the [[zettel identifier|00001006050000]].
The highest zettel identifier, which is a number, comes first.
You change that with the ""''_sort''"" query parameter.
Alternatively, you can also use the ""''_order''"" query parameter.
It is an alias.

Its value is the name of a metadata key, optionally prefixed with a hyphen-minus character (""''-''"", U+002D).
According to the [[type|00001006030000]] of a metadata key, the list of zettel is sorted.
If hyphen-minus is given, the order is descending, else ascending.

If you want a random list of zettel, specify the value ""_random"" in place of the metadata key.
""''_sort=_random''"" (or ""''_order=_random''"") is the query parameter in this case.
If can be combined with ""[[''_limit=1''|00001012051830]]"" to obtain just one random zettel.

Currently, only the first occurrence of ''_sort'' is recognized.
In the future it will be possible to specify a combined sort key.

id: 00001012052400
title: API: Map metadata values to list of zettel identifier
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210216172944
modified: 20220627183323
modified: 20220912112253

**Note**: this endpoint is deprecated since v0.7 and will be removed in v0.8.
Please use a [[query|00001012051400]] instead.
---
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.

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''.
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
# 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''.
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/m?_key=tags
# 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 ''"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: 00001012053300
title: API: Retrieve metadata and content of an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20211004093206
modified: 20220724163741
modified: 20220908162927

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

; ''"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).
In this case, add an additional query parameter ''part=PART''.
Valid values for [[''PART''|00001012920800]] are ""zettel"", ""[[meta|00001012053400]]"", and ""content"" (the default value).

````sh
# curl 'http://127.0.0.1:23123/z/00001012053300'
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
...
````

````sh
# curl 'http://127.0.0.1:23123/z/00001012053300?_part=zettel'
# curl 'http://127.0.0.1:23123/z/00001012053300?part=zettel'
title: API: Retrieve metadata and content of an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk

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
...
````

=== HTTP Status codes
; ''200''
: Retrieval was successful, the body contains an appropriate JSON object / plain zettel data.
; ''204''
: Request was valid, but there is no data to be returned.
  Most likely, you specified the query parameter ''_part=content'', but the zettel does not contain any content.
  Most likely, you specified the query parameter ''part=content'', but the zettel does not contain any content.
; ''400''
: Request was not valid. 
  There are several reasons for this.
  Maybe the [[zettel identifier|00001006050000]] did not consists of exactly 14 digits.
; ''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: 00001012053400
title: API: Retrieve metadata of an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210726174524
modified: 20220202112048
modified: 20220908162635

The [[endpoint|00001012920000]] to work with metadata of a specific zettel is ''/m/{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/00001012053400''[^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/m/00001012053400

: References an embedded JSON object with only string values.
  The name/value pairs of this objects are interpreted as the metadata of the new zettel.
  Please consider the [[list of supported metadata keys|00001006020000]] (and their value types).
; ''"rights"''
: An integer number that describes the [[access rights|00001012921200]] for the zettel.

[!plain]Additionally, you can retrieve the plain metadata of a zettel, without using JSON.
Just change the [[endpoint|00001012920000]] to ''/z/{ID}?_part=meta''
Just change the [[endpoint|00001012920000]] to ''/z/{ID}?part=meta''

````sh
# curl 'http://127.0.0.1:23123/z/00001012053400?_part=meta'
# curl 'http://127.0.0.1:23123/z/00001012053400?part=meta'
title: API: Retrieve metadata of an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
````

=== HTTP Status codes

id: 00001012053500
title: API: Retrieve evaluated metadata and content of an existing zettel in various encodings
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210726174524
modified: 20220410153546
modified: 20220908162843

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":{"title":[{"t":"Text","s":"API:"},{"t":"Space"},{"t":"Text","s":"Retrieve"},{"t":"Space"},{"t":"Text","s":"evaluated"},{"t":"Space"},{"t":"Text","s":"metadata"},{"t":"Space"},{"t":"Text","s":"and"},{"t":"Space"},{"t":"Text","s":"content"},{"t":"Space"},{"t":"Text","s":"of"},{"t":"Space"},{"t":"Text","s":"an"},{"t":"Space"},{"t":"Text","s":"existing"},{"t":"Space"},{"t":"Text","s":"zettel"},{"t":"Space"},{"t":"Text","s":"in"},{"t":"Space"}, ...
```

To select another encoding, you can provide a query parameter ''_enc=[[ENCODING|00001012920500]]''.
The default encoding is ""[[zjson|00001012920503]]"".
To select another encoding, you can provide a query parameter ''enc=ENCODING''.
The default value for [[''ENCODING''|00001012920500]] is ""[[zjson|00001012920503]]"".
Others are ""[[html|00001012920510]]"", ""[[text|00001012920519]]"", and some more.
```sh
# curl 'http://127.0.0.1:23123/v/00001012053500?_enc=html'
# curl 'http://127.0.0.1:23123/v/00001012053500?enc=html'
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>API: Retrieve evaluated metadata and content of an existing zettel in various encodings</title>
<meta name="zs-role" content="manual">
<meta name="keywords" content="api, manual, zettelstore">
<meta name="zs-syntax" content="zmk">
<meta name="zs-back" content="00001012000000">
<meta name="zs-backward" content="00001012000000">
<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-published" content="00001012053500">
</head>
<body>
<p>The <a href="00001012920000">endpoint</a> to work with evaluated metadata and content of a specific zettel is <kbd>/v/{ID}</kbd>, where <kbd>{ID}</kbd> is a placeholder for the <a href="00001006050000">zettel identifier</a>.</p>
...
```

You also can use the query parameter ''_part=[[PART|00001012920800]]'' to specify which parts of a zettel must be encoded.
You also can use the query parameter ''part=PART'' to specify which [[parts|00001012920800]] of a zettel must be encoded.
In this case, its default value is ''content''.
```sh
# curl 'http://127.0.0.1:23123/v/00001012053500?_enc=html&_part=meta'
# curl 'http://127.0.0.1:23123/v/00001012053500?enc=html&part=meta'
<meta name="zs-title" content="API: Retrieve evaluated metadata and content of an existing zettel in various encodings">
<meta name="zs-role" content="manual">
<meta name="keywords" content="api, manual, zettelstore">
<meta name="zs-syntax" content="zmk">
<meta name="zs-back" content="00001012000000">
<meta name="zs-backward" content="00001012000000">
<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">
```

=== 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.
  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: 00001012053600
title: API: Retrieve parsed metadata and content of an existing zettel in various encodings
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210126175322
modified: 20211124180746
modified: 20220908163514

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

A __parsed__ zettel is basically an [[unevaluated|00001012053500]] zettel: the zettel is read and analyzed, but its content is not __evaluated__.
By using this endpoint, you are able to retrieve the structure of a zettel before it is evaluated.

For example, to retrieve some data about this zettel you are currently viewing, just send a HTTP GET request to the endpoint ''/v/00001012053600''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header].

=== 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.
  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: 00001012053900
title: API: Retrieve unlinked references to an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20211119133357
modified: 20220805144656
modified: 20220913152019

The value of a personal Zettelstore is determined in part by explicit connections between related zettel.
If the number of zettel grow, some of these connections are missing.
There are various reasons for this.
Maybe, you forgot that a zettel exists.
Or you add a zettel later, but forgot that previous zettel already mention its title.

This call searches within all zettel whether the title of the specified zettel occurs there.
The other zettel must not link to the specified zettel.
The title must not occur within a link (e.g. to another zettel), in a [[heading|00001007030300]], in a [[citation|00001007040340]], and must have a uniform formatting.
The match must be exact, but is case-insensitive.

If the title of the specified zettel contains some extra character that probably reduce the number of found unlinked references,
you can specify the title phase to be searched for as a query parameter ''_phrase'':
you can specify the title phase to be searched for as a query parameter ''phrase'':

````
# curl 'http://127.0.0.1:23123/u/00001007000000?phrase=markdown'
{"id": "00001007000000","meta": {...},"list": [{"id": "00001008010000","meta": {...},"rights":62},{"id": "00001004020000","meta": {...},"rights":62}]}
````

In addition, you are allowed to specify all query parameter to [[select zettel based on their metadata|00001012051810]], to [[limit the length of the returned list|00001012051830]], and to [[sort the returned list|00001012052000]].
You are allowed to limit the search by a [[search expression|00001012051840]], which may search for zettel content.
%%TODO: In addition, you are allowed to limit the search by a [[query expression|00001012051840]], which may search for zettel content.

=== Keys
The following top-level JSON keys are returned:
; ''id''
: The [[zettel identifier|00001006050000]] for which the unlinked references were requested.
; ''meta'':
: The metadata of the zettel, encoded as a JSON object.

id: 00001012080100
title: API: Execute commands
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20211230230441
modified: 20220805174227
modified: 20220908163125

The [[endpoint|00001012920000]] ''/x'' allows you to execute some (administrative) commands.
To differentiate between the possible commands, you have to set the query parameter ''_cmd'' to a specific value:
To differentiate between the possible commands, you have to set the query parameter ''cmd'' to a specific value:

; ''authenticated''
: [[Check for authentication|00001012080200]]
; ''refresh''
: [[Refresh internal data|00001012080500]]

Other commands will be defined in the future.

id: 00001012080200
title: API: Check for authentication
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20220103224858
modified: 20220805174236
modified: 20220908163156

API clients typically wants to know, whether [[authentication is enabled|00001010040100]] or not.
If authentication is enabled, they present some form of user interface to get user name and password for the actual authentication.
Then they try to [[obtain an access token|00001012050200]].
If authentication is disabled, these steps are not needed.

To check for enabled authentication, you must send a HTTP POST request to the [[endpoint|00001012920000]] ''/x'' and you must specify the query parameter ''_cmd=authenticated''.
To check for enabled authentication, you must send a HTTP POST request to the [[endpoint|00001012920000]] ''/x'' and you must specify the query parameter ''cmd=authenticated''.

```sh
# curl -X POST 'http://127.0.0.1:23123/x?_cmd=authenticated'
# curl -X POST 'http://127.0.0.1:23123/x?cmd=authenticated'
```

If authentication is not enabled, you will get a HTTP status code 200 (OK) with an empty HTTP body.

Otherwise, authentication is enabled.
If you provide a valid access token, you will receive a HTTP status code 204 (No Content) with an empty HTTP body.
If you did not provide a valid access token (with is the typical case), you will get a HTTP status code 401 (Unauthorized), again with an empty HTTP body.

=== HTTP Status codes
; ''200''
: Authentication is disabled.
; ''204''
: Authentication is enabled and a valid access token was provided.
; ''400''
: Request was not valid. 
  There are several reasons for this.
  Most likely, no query parameter ''_cmd'' was given, or it did not contain the value ""authenticate"".
  Most likely, no query parameter ''cmd'' was given, or it did not contain the value ""authenticate"".
; ''401''
: Authentication is enabled and not valid access token was provided.

id: 00001012080500
title: API: Refresh internal data
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20211230230441
modified: 20220805174246
modified: 20220908163223

Zettelstore maintains some internal data to allow faster operations.

One example is the [[content search|00001012051840]] for a term: Zettelstore does not need to scan all zettel to find all occurrences for the term.
Instead, all word are stored internally, with a list of zettel where they occur.

Another example is the way to determine which zettel are stored in a [[ZIP file|00001004011200]].
Scanning a ZIP file is a lengthy operation, therefore Zettelstore maintains a directory of zettel for each ZIP file.

All these internal data may become stale.
This should not happen, but when it comes e.g. to file handling, every operating systems behaves differently in very subtle ways.

To avoid stopping and re-starting Zettelstore, you can use the API to force Zettelstore to refresh its internal data if you think it is needed.
To do this, you must send a HTTP POST request to the [[endpoint|00001012920000]] ''/x'' and you must specify the query parameter ''_cmd=refresh''.
To do this, you must send a HTTP POST request to the [[endpoint|00001012920000]] ''/x'' and you must specify the query parameter ''cmd=refresh''.

```sh
# curl -X POST 'http://127.0.0.1:23123/x?_cmd=refresh'
# curl -X POST 'http://127.0.0.1:23123/x?cmd=refresh'
```

If successful, you will get a HTTP status code 204 (No Content) with an empty HTTP body.

The request will be successful if either:
* [[Authentication is enabled|00001010040100]] and you [[provide a valid access token|00001012050600]],
* Authentication is not enabled and you started Zettelstore with the [[run-simple|00001004051100]] command or [[expert-mode|00001004020000#expert-mode]] is set to ""true"".

=== HTTP Status codes
; ''204''
: Operation was successful, the body is empty.
; ''400''
: Request was not valid. 
  There are several reasons for this.
  Most likely, no query parameter ''_cmd'' was given, or it did not contain the value ""refresh"".
  Most likely, no query parameter ''cmd'' was given, or it did not contain the value ""refresh"".
; ''403''
: You are not allowed to perform this operation.

id: 00001012920000
title: Endpoints used by the API
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
created: 20210126175322
modified: 20220627183408
modified: 20220912115218

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: [[map metadata values|00001012052400]] | GET: [[retrieve metadata|00001012053400]] | **M**etadata
| ''m'' | GET: [[map metadata values|00001012052400]] (deprecated) | GET: [[retrieve metadata|00001012053400]] | **M**etadata
| ''o'' |  | GET: [[list zettel order|00001012054000]] | **O**rder
| ''p'' |  | GET: [[retrieve parsed zettel|00001012053600]]| **P**arsed
| ''q'' | GET: [[query zettel list|00001012051400]] |  | **Q**uery
| ''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: 00001012920503
title: ZJSON Encoding
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
created: 20210126175322
modified: 20220422191748
modified: 20220908163450

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 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]].
* [[//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''.

A full zettel encoding results in a JSON object with two keys: ''"meta"'' and ''"content"''.
Both values are the same as if you have requested just the appropriate [[part|00001012920800]].

=== Encoding of metadata

id: 00001012920516
title: Sexpr Encoding
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
created: 20220422181104
modified: 20220724170637
modified: 20220908163427

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]].
* [[//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).

id: 00001017000000
title: Tips and Tricks
role: manual
tags: #manual #zettelstore
syntax: zmk
created: 20220803170112
modified: 20220805174255
modified: 20220916132030

=== Welcome Zettel
* **Problem:** You want to put your Zettelstore into the public and need a starting zettel for your users.
  In addition, you still want a ""home zettel"", with all your references to internal, non-public zettel.
  Zettelstore only allows to specify one [[''home-zettel''|00001004020000#home-zettel]].
* **Solution:**
*# Create a new zettel with all your references to internal, non-public zettel.
   Let's assume this zettel receives the zettel identifier ''20220803182600''.
*# Create the zettel that should serve as the starting zettel for your users.
   It must have syntax [[Zettelmarkup|00001008000000#zmk]], i.e. the syntax metadata must be set to ''zmk''.
   If needed, set the runtime configuration [[''home-zettel|00001004020000#home-zettel]] to the value of the identifier of this zettel.
*# At the beginning of the start zettel, add the following [[Zettelmarkup|00001007000000]] text in a separate paragraph: ``{{{20220803182600}}}`` (you have to adapt to the actual value of the zettel identifier for your non-public home zettel).
* **Discussion:** As stated in the description for a [[transclusion|00001007031100]], a transclusion will be ignored, if the transcluded zettel is not visible to the current user.
  In effect, the transclusion statement (above paragraph that contained ''{{{...}}}'') is ignored when rendering the zettel.

=== Role-specific Layout of Zettel in Web User Interface (WebUI)
[!role-css]
* **Problem:** You want to add some CSS when displaying zettel of a specific [[role|00001006020000#role]].
  For example, you might want to add a yellow background color for all [[configuration|00001006020100#configuration]] zettel.
  Or you want a multi-column layout.
* **Solution:** If you enable [[''expert-mode''|00001004020000#expert-mode]], you will have access to a zettel called ""[[Zettelstore Role to CSS Map|00000000029000]]"" (its identifier is ''00000000029000'').
  This zettel maps a role name to a zettel that must contain the role-specific CSS code.

  First, create a zettel containing the needed CSS: give it any title, its role is preferably ""configuration"" (but this is not a must).
  Set its [[''syntax''|00001006020000#syntax]] must be set to ""[[css|00001008000000#css]]"".
  The content must contain the role-specific CSS code, for example ``body {background-color: #FFFFD0}``for a background in a light yellow color.

  Let's assume, the newly created CSS zettel got the identifier ''20220825200100''.

  Now, you have to connect this zettel to the zettel called ""Zettelstore Role CSS Map"".
  Since you have enabled ''expert-mode'', you are allowed to modify it.
  Add the following metadata ''css-configuration-zid: 20220825200100'' to assign the role-specific CSS code for the role ""configuration"" to the CSS zettel containing that CSS.

  In general, its role-assigning metadata must be like this pattern: ''css-ROLE-zid: ID'', where ''ROLE'' is the placeholder for the role, and ''ID'' for the zettel identifier containing CSS code.
  It is allowed to assign more than one role to a specific CSS zettel.
* **Discussion:** you have to ensure that the CSS zettel is allowed to be read by the intended audience of the zettel with that given role.
  For example, if you made zettel with a specific role public visible, the CSS zettel must also have a [[''visibility: public''|00001010070200]] metadata.
* **Extension:** if you have already established a role-specific layout for zettel, but you additionally want just one another zettel with another role to be rendered with the same CSS, you have to add metadata to the one zettel: ''css-role: ROLE'', where ''ROLE'' is the placeholder for the role that already is assigned to a specific CSS-based layout.

=== Zettel synchronization with iCloud (Apple)
* **Problem:** You use Zettelstore on various macOS computers and you want to use the sameset of zettel across all computers.
* **Solution:** Place your zettel in an iCloud folder.

  To configure Zettelstore to use the folder, you must specify its location within you directory structure as [[''box-uri-X''|00001004010000#box-uri-x]] (replace ''X'' with an appropriate number).
  Your iCloud folder is typically placed in the folder ''~/Library/Mobile Documents/com~apple~CloudDocs''.
  The ""''~''"" is a shortcut and specifies your home folder.

  Unfortunately, Zettelstore does not yet support this shortcut.
  Therefore you must replace it with the absolute name of your home folder.
  In addition, a space character is not allowed in an URI.
  You have to replace it with the sequence ""''%20''"".

  Let us assume, that you stored your zettel box inside the folder ""zettel"", which is located top-level in your iCloud folder.
  In this case, you must specify the following box URI within the startup configuration: ''box-uri-1: dir:///Users/USERNAME/Library/Mobile%20Documents/com~apple~CloudDocs/zettel'', replacing ''USERNAME'' with the username of that specific computer (and assuming you want to use it as the first box).
* **Solution 2:** If you typically start your Zettelstore on the command line, you could use the ''-d DIR'' option for the [[''run''|00001004051000#d]] sub-command.
  In this case you are allowed to use the character ""''~''"".

  ''zettelstore run -d ~/Library/Mobile\\ Documents/com\\~apple\\~CloudDocs/zettel''

  (The ""''\\''"" is needed by the command line processor to mask the following character to be processed in unintended ways.)
* **Discussion:** Zettel files are synchronized between your computers via iCloud.
  Is does not matter, if one of your computer is offline / switched off.
  iCloud will synchronize the zettel files if it later comes online.

  However, if you use more than one computer simultaneously, you must be aware that synchronization takes some time.
  It might take several seconds, maybe longer, that new new version of a zettel appears on the other computer.
  If you update the same zettel on multiple computers at nearly the same time, iCloud will not be able to synchronize the different versions in a safe manner.
  Zettelstore is intentionally not aware of any synchronization within its zettel boxes.

  If Zettelstore behaves strangely after a synchronization took place, the page about [[Troubleshooting|00001018000000#working-with-files]] might contain some useful information.

id: 00001018000000
title: Troubleshooting
role: manual
tags: #manual #zettelstore
syntax: zmk
modified: 20220805174305
modified: 20220823195041

This page lists some problems and their solutions that may occur when using your Zettelstore.

=== Installation
* **Problem:** When you double-click on the Zettelstore executable icon, macOS complains that Zettelstore is an application from an unknown developer.
  Therefore, it will not start Zettelstore.
** **Solution:** Press the ''Ctrl'' key while opening the context menu of the Zettelstore executable with a right-click.
   A dialog is then opened where you can acknowledge that you understand the possible risks when you start Zettelstore.
   This dialog is only resented once for a given Zettelstore executable.
* **Problem:** When you double-click on the Zettelstore executable icon, Windows complains that Zettelstore is an application from an unknown developer.
** **Solution:** Windows displays a dialog where you can acknowledge possible risks and allows to start Zettelstore.

=== Authentication
* **Problem:** [[Authentication is enabled|00001010040100]] for a local running Zettelstore and there is a valid [[user zettel|00001010040200]] for the owner.
  But entering user name and password at the [[web user interface|00001014000000]] seems to be ignored, while entering a wrong password will result in an error message.
** **Explanation:** A local running Zettelstore typically means, that you are accessing the Zettelstore using an URL with schema ''http://'', and not ''https://'', for example ''http://localhost:23123''.
   The difference between these two is the missing encryption of user name / password and for the answer of the Zettelstore if you use the ''http://'' schema.
   To be secure by default, the Zettelstore will not work in an insecure environment.
** **Solution 1:** If you are sure that your communication medium is safe, even if you use the ''http:/\/'' schema (for example, you are running the Zettelstore on the same computer you are working on, or if the Zettelstore is running on a computer in your protected local network), then you could add the entry ''insecure-cookie: true'' in you [[startup configuration|00001004010000#insecure-cookie]] file.
** **Solution 2:** If you are not sure about the security of your communication medium (for example, if unknown persons might use your local network), then you should run an [[external server|00001010090100]] in front of your Zettelstore to enable the use of the ''https://'' schema.

=== Working with Zettel Files
* **Problem:** When you delete a zettel file by removing it from the ""disk"", e.g. by dropping it into the trash folder, by dragging into another folder, or by removing it from the command line, Zettelstore sometimes did not detect that change.
  If you access the zettel via Zettelstore, a fatal error is reported.
** **Explanation:** Sometimes, the operating system does not tell Zettelstore about the removed zettel.
   This occurs mostly under MacOS.
** **Solution 1:** If you are running Zettelstore in [[""simple-mode""|00001004051100]] or if you have enabled [[''expert-mode''|00001004020000#expert-mode]], you are allowed to refresh the internal data by selecting ""Refresh"" in the Web User Interface (you find it in the menu ""Lists"").
** **Solution 2:** There is an [[API|00001012080500]] call to make Zettelstore aware of this change.
** **Solution 3:** If you have an enabled [[Administrator Console|00001004100000]] you can use the command [[''refresh''|00001004101000#refresh]] to make your changes visible.
** **Solution 4:** You configure the zettel box as [[""simple""|00001004011400]].

// Some important ZettelIDs.
const (
	Invalid = Zid(0) // Invalid is a Zid that will never be valid
)

// ZettelIDs that are used as Zid more than once.
//
// Note: if you change some values, ensure that you also change them in the
//       constant box. They are mentioned there literally, because these
//       constants are not available there.
// Constant box. They are mentioned there literally, because these
// constants are not available there.
var (
	ConfigurationZid   = MustParse(api.ZidConfiguration)
	BaseTemplateZid    = MustParse(api.ZidBaseTemplate)
	LoginTemplateZid   = MustParse(api.ZidLoginTemplate)
	ListTemplateZid    = MustParse(api.ZidListTemplate)
	ZettelTemplateZid  = MustParse(api.ZidZettelTemplate)
	InfoTemplateZid    = MustParse(api.ZidInfoTemplate)
	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)
)

	result[11] = byte(minute%10) + '0'
	result[12] = byte(second/10) + '0'
	result[13] = byte(second%10) + '0'
}

// IsValid determines if zettel id is a valid one, e.g. consists of max. 14 digits.
func (zid Zid) IsValid() bool { return 0 < zid && zid <= maxZid }

// ZidLayout to transform a date into a Zid and into other internal dates.
const ZidLayout = "20060102150405"

// New returns a new zettel id based on the current time.
func New(withSeconds bool) Zid {
	now := time.Now()
	now := time.Now().Local()
	var s string
	if withSeconds {
		s = now.Format("20060102150405")
		s = now.Format(ZidLayout)
	} else {
		s = now.Format("20060102150400")
	}
	res, err := Parse(s)
	if err != nil {
		panic(err)
	}
	return res
}

// IsComputed returns true, if metadata is computed and not set by the user.
func (kd *DescriptionKey) IsComputed() bool { return kd.usage >= usageComputed }

// IsProperty returns true, if metadata is a computed property.
func (kd *DescriptionKey) IsProperty() bool { return kd.usage >= usageProperty }

// IsStoredComputed retruns true, if metadata is computed, but also stored.
func (kd *DescriptionKey) IsStoredComputed() bool { return kd.usage == usageComputed }

var registeredKeys = make(map[string]*DescriptionKey)

func registerKey(name string, t *DescriptionType, usage keyUsage, inverse string) {
	if _, ok := registeredKeys[name]; ok {
		panic("Key '" + name + "' already defined")
	}
	if inverse != "" {

// IsProperty returns true, if key denotes a property metadata value.
func IsProperty(name string) bool {
	if kd, ok := registeredKeys[name]; ok {
		return kd.IsProperty()
	}
	return false
}

// IsStoredComputed returns true, if key denotes a computed metadata key that is stored.
func IsStoredComputed(name string) bool {
	if kd, ok := registeredKeys[name]; ok {
		return kd.IsStoredComputed()
	}
	return false
}

// Inverse returns the name of the inverse key.
func Inverse(name string) string {
	if kd, ok := registeredKeys[name]; ok {
		return kd.Inverse
	}
	return ""

	registerKey(api.KeyID, TypeID, usageComputed, "")
	registerKey(api.KeyTitle, TypeZettelmarkup, usageUser, "")
	registerKey(api.KeyRole, TypeWord, usageUser, "")
	registerKey(api.KeyTags, TypeTagSet, usageUser, "")
	registerKey(api.KeySyntax, TypeWord, usageUser, "")

	registerKey(api.KeyAllTags, TypeTagSet, usageProperty, "")
	registerKey(api.KeyAuthor, TypeString, usageUser, "")
	registerKey(api.KeyBack, TypeIDSet, usageProperty, "")
	registerKey(api.KeyBackward, TypeIDSet, usageProperty, "")
	registerKey(api.KeyBoxNumber, TypeNumber, usageProperty, "")
	registerKey(api.KeyContentTags, TypeTagSet, usageProperty, "")
	registerKey(api.KeyCopyright, TypeString, usageUser, "")
	registerKey(api.KeyCreated, TypeTimestamp, usageComputed, "")
	registerKey(api.KeyCredential, TypeCredential, usageUser, "")
	registerKey(api.KeyDead, TypeIDSet, usageProperty, "")
	registerKey(api.KeyFolge, TypeIDSet, usageProperty, "")
	registerKey(api.KeyForward, TypeIDSet, usageProperty, "")
	registerKey(api.KeyLang, TypeWord, usageUser, "")
	registerKey(api.KeyLicense, TypeEmpty, usageUser, "")
	registerKey(api.KeyModified, TypeTimestamp, usageComputed, "")

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

	switch Type(key) {
	case TypeTagSet:
		addSet(m, key, strings.ToLower(v), func(s string) bool { return s[0] == '#' })
		addSet(m, key, strings.ToLower(v), func(s string) bool { return s[0] == '#' && len(s) > 1 })
	case TypeWord:
		m.Set(key, strings.ToLower(v))
	case TypeWordSet:
		addSet(m, key, strings.ToLower(v), func(s string) bool { return true })
	case TypeID:
		if _, err := id.Parse(v); err == nil {
			m.Set(key, v)

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

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

import (
	"strings"
	"testing"

	"zettelstore.de/c/api"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/input"
)

		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)
		}
	}
}

func TestTags(t *testing.T) {
	t.Parallel()
	testcases := []struct {
		src string
		exp string
	}{
		{"", ""},
		{api.KeyTags + ":", ""},
		{api.KeyTags + ": c", ""},
		{api.KeyTags + ": #", ""},
		{api.KeyTags + ": #c", "c"},
		{api.KeyTags + ": #c #", "c"},
		{api.KeyTags + ": #c #b", "b c"},
		{api.KeyTags + ": #c # #", "c"},
		{api.KeyTags + ": #c # #b", "b c"},
	}
	for i, tc := range testcases {
		m := parseMetaStr(tc.src)
		tags, found := m.GetTags(api.KeyTags)
		if !found {
			if tc.exp != "" {
				t.Errorf("%d / %q: no %s found", i, tc.src, api.KeyTags)
			}
			continue
		}
		if tc.exp == "" && len(tags) > 0 {
			t.Errorf("%d / %q: expected no %s, but got %v", i, tc.src, api.KeyTags, tags)
			continue
		}
		got := strings.Join(tags, " ")
		if tc.exp != got {
			t.Errorf("%d / %q: expected %q, got: %q", i, tc.src, tc.exp, got)
		}
	}
}

func TestNewFromInput(t *testing.T) {
	t.Parallel()
	testcases := []struct {
		input string
		exp   []meta.Pair
	}{

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

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

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

		}
		m.pairs[key] = strings.Join(values, " ")
	}
}

// SetNow stores the current timestamp under the given key.
func (m *Meta) SetNow(key string) {
	m.Set(key, time.Now().Format("20060102150405"))
	m.Set(key, time.Now().Local().Format(id.ZidLayout))
}

// BoolValue returns the value interpreted as a bool.
func BoolValue(value string) bool {
	if len(value) > 0 {
		switch value[0] {
		case '0', 'f', 'F', 'n', 'N':

		return BoolValue(value)
	}
	return false
}

// TimeValue returns the time value of the given value.
func TimeValue(value string) (time.Time, bool) {
	if t, err := time.Parse("20060102150405", value); err == nil {
	if t, err := time.Parse(id.ZidLayout, value); err == nil {
		return t, true
	}
	return time.Time{}, false
}

// GetTime returns the time value of the given key.
func (m *Meta) GetTime(key string) (time.Time, bool) {

			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: "Transclusion",
		zmk:   `{{{http://example.com/image}}}{width="100px"}`,
		expect: expectMap{
			encoderZJSON: `[{"":"Transclude","a":{"width":"100px"},"q":"external","s":"http://example.com/image"}]`,
			encoderHTML:  `<p><img class="external" src="http://example.com/image" width="100px"></p>`,
			encoderSexpr: `((TRANSCLUDE (("width" "100px")) (EXTERNAL "http://example.com/image")))`,
			encoderText:  "",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "",
		zmk:   ``,
		expect: expectMap{
			encoderZJSON: `[]`,
			encoderHTML:  ``,
			encoderSexpr: `()`,

			encoderHTML:  `<a href="../relative">R</a>`,
			encoderSexpr: `((LINK-HOSTED () "../relative" (TEXT "R")))`,
			encoderText:  `R`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Search link w/o text",
		zmk:   `[[search:title:syntax]]`,
		descr: "Query link w/o text",
		zmk:   `[[query:title:syntax]]`,
		expect: expectMap{
			encoderZJSON: `[{"":"Link","q":"search","s":"title:syntax"}]`,
			encoderHTML:  `<a href="?_s=title%3Asyntax">title:syntax</a>`,
			encoderSexpr: `((LINK-SEARCH () "title:syntax"))`,
			encoderZJSON: `[{"":"Link","q":"query","s":"title:syntax"}]`,
			encoderHTML:  `<a href="?q=title%3Asyntax">title:syntax</a>`,
			encoderSexpr: `((LINK-QUERY () "title:syntax"))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Search link with text",
		zmk:   `[[S|search:title:syntax]]`,
		descr: "Query link with text",
		zmk:   `[[Q|query:title:syntax]]`,
		expect: expectMap{
			encoderZJSON: `[{"":"Link","q":"search","s":"title:syntax","i":[{"":"Text","s":"S"}]}]`,
			encoderHTML:  `<a href="?_s=title%3Asyntax">S</a>`,
			encoderSexpr: `((LINK-SEARCH () "title:syntax" (TEXT "S")))`,
			encoderText:  `S`,
			encoderZJSON: `[{"":"Link","q":"query","s":"title:syntax","i":[{"":"Text","s":"Q"}]}]`,
			encoderHTML:  `<a href="?q=title%3Asyntax">Q</a>`,
			encoderSexpr: `((LINK-QUERY () "title:syntax" (TEXT "Q")))`,
			encoderText:  `Q`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Dummy Embed",
		zmk:   `{{abc}}`,
		expect: expectMap{
			encoderZJSON: `[{"":"Embed","s":"abc"}]`,
			encoderHTML:  `<img src="abc">`,
			encoderSexpr: `((EMBED () (EXTERNAL "abc") ""))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Inline HTML Zettel",
		zmk:   `@@<hr>@@{="html"}`,
		expect: expectMap{
			encoderZJSON: `[{"":"HTML","s":"<hr>"}]`,
			encoderHTML:  `<hr>`,
			encoderSexpr: `((LITERAL-HTML () "<hr>"))`,
			encoderText:  `<hr>`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "",
		zmk:   ``,
		expect: expectMap{
			encoderZJSON: `[]`,
			encoderHTML:  ``,
			encoderSexpr: `()`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
}

	case *ast.NestedListNode:
		return t.getNestedList(n)
	case *ast.DescriptionListNode:
		return t.getDescriptionList(n)
	case *ast.TableNode:
		return t.getTable(n)
	case *ast.TranscludeNode:
		return sxpf.NewPairFromValues(sexpr.SymTransclude, getReference(n.Ref))
		return sxpf.NewPairFromValues(sexpr.SymTransclude, getAttributes(n.Attrs), getReference(n.Ref))
	case *ast.BLOBNode:
		return getBLOB(n)
	case *ast.TextNode:
		return sxpf.NewPairFromValues(sexpr.SymText, sxpf.NewString(n.Text))
	case *ast.TagNode:
		return sxpf.NewPairFromValues(sexpr.SymTag, sxpf.NewString(n.Tag))
	case *ast.SpaceNode:

	ast.RefStateInvalid:  sexpr.SymLinkInvalid,
	ast.RefStateZettel:   sexpr.SymLinkZettel,
	ast.RefStateSelf:     sexpr.SymLinkSelf,
	ast.RefStateFound:    sexpr.SymLinkFound,
	ast.RefStateBroken:   sexpr.SymLinkBroken,
	ast.RefStateHosted:   sexpr.SymLinkHosted,
	ast.RefStateBased:    sexpr.SymLinkBased,
	ast.RefStateSearch:   sexpr.SymLinkSearch,
	ast.RefStateQuery:    sexpr.SymLinkQuery,
	ast.RefStateExternal: sexpr.SymLinkExternal,
}

func (t *transformer) getLink(ln *ast.LinkNode) *sxpf.Pair {
	return sxpf.NewPair(
		mapGetS(mapRefStateLink, ln.Ref.State),
		sxpf.NewPair(

	ast.RefStateInvalid:  sexpr.SymRefStateInvalid,
	ast.RefStateZettel:   sexpr.SymRefStateZettel,
	ast.RefStateSelf:     sexpr.SymRefStateSelf,
	ast.RefStateFound:    sexpr.SymRefStateFound,
	ast.RefStateBroken:   sexpr.SymRefStateBroken,
	ast.RefStateHosted:   sexpr.SymRefStateHosted,
	ast.RefStateBased:    sexpr.SymRefStateBased,
	ast.RefStateSearch:   sexpr.SymRefStateSearch,
	ast.RefStateQuery:    sexpr.SymRefStateQuery,
	ast.RefStateExternal: sexpr.SymRefStateExternal,
}

func getReference(ref *ast.Reference) *sxpf.Pair {
	return sxpf.NewPair(
		mapGetS(mapRefStateS, ref.State),
		sxpf.NewPair(

		v.visitNestedList(n)
	case *ast.DescriptionListNode:
		v.visitDescriptionList(n)
	case *ast.TableNode:
		v.visitTable(n)
	case *ast.TranscludeNode:
		v.writeNodeStart(zjson.TypeTransclude)
		v.visitAttributes(n.Attrs)
		v.writeContentStart(zjson.NameString2)
		writeEscaped(&v.b, mapRefState[n.Ref.State])
		v.writeContentStart(zjson.NameString)
		writeEscaped(&v.b, n.Ref.String())
	case *ast.BLOBNode:
		v.visitBLOB(n)
	case *ast.TextNode:

	ast.RefStateInvalid:  zjson.RefStateInvalid,
	ast.RefStateZettel:   zjson.RefStateZettel,
	ast.RefStateSelf:     zjson.RefStateSelf,
	ast.RefStateFound:    zjson.RefStateFound,
	ast.RefStateBroken:   zjson.RefStateBroken,
	ast.RefStateHosted:   zjson.RefStateHosted,
	ast.RefStateBased:    zjson.RefStateBased,
	ast.RefStateSearch:   zjson.RefStateSearch,
	ast.RefStateQuery:    zjson.RefStateQuery,
	ast.RefStateExternal: zjson.RefStateExternal,
}

func (v *visitor) visitLink(ln *ast.LinkNode) {
	v.writeNodeStart(zjson.TypeLink)
	v.visitAttributes(ln.Attrs)
	v.writeContentStart(zjson.NameString2)
	writeEscaped(&v.b, mapRefState[ln.Ref.State])
	v.writeContentStart(zjson.NameString)
	if ln.Ref.State == ast.RefStateSearch {
	if ln.Ref.State == ast.RefStateQuery {
		writeEscaped(&v.b, ln.Ref.Value)
	} else {
		writeEscaped(&v.b, ln.Ref.String())
	}
	if len(ln.Inlines) > 0 {
		v.writeContentStart(zjson.NameInline)
		ast.Walk(v, &ln.Inlines)

		v.visitNestedList(n)
	case *ast.DescriptionListNode:
		v.visitDescriptionList(n)
	case *ast.TableNode:
		v.visitTable(n)
	case *ast.TranscludeNode:
		v.b.WriteStrings("{{{", n.Ref.String(), "}}}")
		v.visitAttributes(n.Attrs)
	case *ast.BLOBNode:
		v.visitBLOB(n)
	case *ast.TextNode:
		v.visitText(n)
	case *ast.TagNode:
		v.b.WriteStrings("#", n.Tag)
	case *ast.SpaceNode:

			v.b.WriteByte(' ')
		}
		v.b.WriteString("%%")
		v.visitAttributes(ln.Attrs)
		v.b.WriteByte(' ')
		v.b.Write(ln.Content)
	case ast.LiteralHTML:
		v.writeLiteral('x', syntaxToHTML(ln.Attrs), ln.Content)
		v.writeLiteral('@', syntaxToHTML(ln.Attrs), ln.Content)
	default:
		panic(fmt.Sprintf("Unknown literal kind %v", ln.Kind))
	}
}

func (v *visitor) writeLiteral(code byte, a attrs.Attributes, content []byte) {
	v.b.WriteBytes(code, code)

//-----------------------------------------------------------------------------
// 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 rss provides a RSS encoding.
package rss

import (
	"bytes"
	"context"
	"encoding/xml"
	"time"

	"zettelstore.de/c/api"
	"zettelstore.de/z/config"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/encoder/textenc"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/query"
)

const ContentType = "application/rss+xml"

type Configuration struct {
	Title            string
	Language         string
	Copyright        string
	Generator        string
	NewURLBuilderAbs func() *api.URLBuilder
}

func (c *Configuration) Setup(ctx context.Context, cfg config.Config) {
	baseURL := kernel.Main.GetConfig(kernel.WebService, kernel.WebBaseURL).(string)
	defVals := cfg.AddDefaultValues(ctx, &meta.Meta{})

	c.Title = cfg.GetSiteName()
	c.Language = defVals.GetDefault(api.KeyLang, "")
	c.Copyright = defVals.GetDefault(api.KeyCopyright, "")
	c.Generator = (kernel.Main.GetConfig(kernel.CoreService, kernel.CoreProgname).(string) +
		" " +
		kernel.Main.GetConfig(kernel.CoreService, kernel.CoreVersion).(string))
	c.NewURLBuilderAbs = func() *api.URLBuilder { return api.NewURLBuilder(baseURL, 'h') }
}

func (c *Configuration) Marshal(q *query.Query, ml []*meta.Meta) ([]byte, error) {
	textEnc := textenc.Create()
	rssItems := make([]*RssItem, 0, len(ml))
	maxPublished := time.Date(1, time.January, 1, 0, 0, 0, 0, time.Local)
	for _, m := range ml {
		var title bytes.Buffer
		titleIns := parser.ParseMetadata(m.GetTitle())
		if _, err := textEnc.WriteInlines(&title, &titleIns); err != nil {
			title.Reset()
			title.WriteString(m.GetTitle())
		}

		itemPublished := ""
		if val, found := m.Get(api.KeyPublished); found {
			if published, err := time.ParseInLocation(id.ZidLayout, val, time.Local); err == nil {
				itemPublished = published.UTC().Format(time.RFC1123Z)
				if maxPublished.Before(published) {
					maxPublished = published
				}
			}
		}

		link := c.NewURLBuilderAbs().SetZid(api.ZettelID(m.Zid.String())).String()
		rssItems = append(rssItems, &RssItem{
			Title:   title.String(),
			Link:    link,
			GUID:    link,
			PubDate: itemPublished,
		})
	}

	rssPublished := ""
	if maxPublished.Year() > 1 {
		rssPublished = maxPublished.UTC().Format(time.RFC1123Z)
	}
	var atomLink *AtomLink
	if s := q.String(); s != "" {
		atomLink = &AtomLink{
			Href: c.NewURLBuilderAbs().AppendQuery(s).String(),
			Rel:  "self",
			Type: ContentType,
		}
	}
	rssFeed := RssFeed{
		Version:       "2.0",
		AtomNamespace: "http://www.w3.org/2005/Atom",
		Channel: &RssChannel{
			Title:         c.Title,
			Link:          c.NewURLBuilderAbs().String(),
			Language:      c.Language,
			Copyright:     c.Copyright,
			PubDate:       rssPublished,
			LastBuildDate: rssPublished,
			Generator:     c.Generator,
			Docs:          "https://www.rssboard.org/rss-specification",
			AtomLink:      atomLink,
			Items:         rssItems,
		},
	}
	return xml.MarshalIndent(&rssFeed, "", "  ")
}

type (
	RssFeed struct {
		XMLName       xml.Name `xml:"rss"`
		Version       string   `xml:"version,attr"`
		AtomNamespace string   `xml:"xmlns:atom,attr"`
		Channel       *RssChannel
	}
	RssChannel struct {
		XMLName       xml.Name `xml:"channel"`
		Title         string   `xml:"title"`
		Link          string   `xml:"link"`
		Description   string   `xml:"description"`
		Language      string   `xml:"language,omitempty"`
		Copyright     string   `xml:"copyright,omitempty"`
		PubDate       string   `xml:"pubDate,omitempty"`       // RFC822
		LastBuildDate string   `xml:"lastBuildDate,omitempty"` // RFC822
		Generator     string   `xml:"generator,omitempty"`
		Docs          string   `xml:"docs,omitempty"`
		AtomLink      *AtomLink
		Items         []*RssItem `xml:"item"`
	}
	AtomLink struct {
		XMLName xml.Name `xml:"atom:link"`
		Href    string   `xml:"href,attr"`
		Rel     string   `xml:"rel,attr"`
		Type    string   `xml:"type,attr"`
	}
	RssItem struct {
		XMLName xml.Name `xml:"item"`
		Title   string   `xml:"title"`
		Link    string   `xml:"link"` // Needed, b/c Miniflux does not use GUID for URL
		GUID    string   `xml:"guid"`
		PubDate string   `xml:"pubDate,omitempty"` // RFC822
	}
)

	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/input"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/parser/cleaner"
	"zettelstore.de/z/parser/draw"
	"zettelstore.de/z/search"
	"zettelstore.de/z/query"
)

// Port contains all methods to retrieve zettel (or part of it) to evaluate a zettel.
type Port interface {
	GetMeta(context.Context, id.Zid) (*meta.Meta, error)
	GetZettel(context.Context, id.Zid) (domain.Zettel, error)
	SelectMeta(ctx context.Context, s *search.Search) ([]*meta.Meta, error)
	SelectMeta(ctx context.Context, q *query.Query) ([]*meta.Meta, error)
}

// EvaluateZettel evaluates the given zettel in the given context, with the
// given ports, and the given environment.
func EvaluateZettel(ctx context.Context, port Port, rtConfig config.Config, zn *ast.ZettelNode) {
	if zn.Syntax == api.ValueSyntaxNone {
		// AST is empty, evaluate to a description list of metadata.
		zn.Ast = evaluateMetadata(zn.Meta)
		return
	}
	EvaluateBlock(ctx, port, rtConfig, &zn.Ast)
}

// EvaluateBlock evaluates the given block list in the given context, with
// the given ports, and the given environment.
func EvaluateBlock(ctx context.Context, port Port, rtConfig config.Config, bns *ast.BlockSlice) {
	evaluateNode(ctx, port, rtConfig, &zn.Ast)
	cleaner.CleanBlockSlice(&zn.Ast)
	evaluateNode(ctx, port, rtConfig, bns)
	cleaner.CleanBlockSlice(bns)
}

// EvaluateInline evaluates the given inline list in the given context, with
// the given ports, and the given environment.
func EvaluateInline(ctx context.Context, port Port, rtConfig config.Config, is *ast.InlineSlice) {
	evaluateNode(ctx, port, rtConfig, is)
	cleaner.CleanInlineSlice(is)

		e.transcludeCount++
		return makeBlockNode(createInlineErrorText(ref, "Invalid", "or", "broken", "transclusion", "reference"))
	case ast.RefStateSelf:
		e.transcludeCount++
		return makeBlockNode(createInlineErrorText(ref, "Self", "transclusion", "reference"))
	case ast.RefStateFound, ast.RefStateHosted, ast.RefStateBased, ast.RefStateExternal:
		return tn
	case ast.RefStateSearch:
	case ast.RefStateQuery:
		e.transcludeCount++
		return e.evalSearchTransclusion(tn.Ref.Value)
		return e.evalQueryTransclusion(tn.Ref.Value)
	default:
		return makeBlockNode(createInlineErrorText(ref, "Illegal", "block", "state", strconv.Itoa(int(ref.State))))
	}

	zid, err := id.Parse(ref.URL.Path)
	if err != nil {
		panic(err)

		if err1 != nil {
			if errors.Is(err1, &box.ErrNotAllowed{}) {
				return nil
			}
			e.transcludeCount++
			return makeBlockNode(createInlineErrorText(ref, "Unable", "to", "get", "zettel"))
		}
		setMetadataFromAttributes(zettel.Meta, tn.Attrs)
		ec := e.transcludeCount
		e.costMap[zid] = transcludeCost{zn: e.marker, ec: ec}
		zn = e.evaluateEmbeddedZettel(zettel)
		e.costMap[zid] = transcludeCost{zn: zn, ec: e.transcludeCount - ec}
		e.transcludeCount = 0 // No stack needed, because embedding is done left-recursive, depth-first.
	}
	e.transcludeCount++
	if ec := cost.ec; ec > 0 {
		e.transcludeCount += cost.ec
	}
	return &zn.Ast
}

func (e *evaluator) evalSearchTransclusion(expr string) ast.BlockNode {
	ml, err := e.port.SelectMeta(e.ctx, search.Parse(expr))
func (e *evaluator) evalQueryTransclusion(expr string) ast.BlockNode {
	q := query.Parse(expr)
	ml, err := e.port.SelectMeta(e.ctx, q)
	if err != nil {
		if errors.Is(err, &box.ErrNotAllowed{}) {
			return nil
		}
		return makeBlockNode(createInlineErrorText(nil, "Unable", "to", "search", "zettel"))
	}
	if len(ml) == 0 {
		return nil
	}
	items := make([]ast.ItemSlice, 0, len(ml))
	for _, m := range ml {
	result := QueryAction(e.ctx, q, ml, e.rtConfig)
		zid := m.Zid.String()
		title, found := m.Get(api.KeyTitle)
		if !found {
			title = zid
		}
		items = append(items, ast.ItemSlice{ast.CreateParaNode(&ast.LinkNode{
			Attrs:   nil,
	if result != nil {
			Ref:     ast.ParseReference(zid),
			Inlines: parser.ParseMetadataNoLink(title),
		})})
	}
	result := &ast.NestedListNode{
		ast.Walk(e, result)
		Kind:  ast.NestedListUnordered,
		Items: items,
		Attrs: nil,
	}
	ast.Walk(e, result)
	return result
}

func (e *evaluator) checkMaxTransclusions(ref *ast.Reference) ast.InlineNode {
	if maxTrans := e.transcludeMax; e.transcludeCount > maxTrans {
		e.transcludeCount = maxTrans + 1
		return createInlineErrorText(ref,
			"Too", "many", "transclusions", "(must", "be", "at", "most", strconv.Itoa(maxTrans)+",",
			"see", "runtime", "configuration", "key", "max-transclusions)")
	}
	return nil
}

func makeBlockNode(in ast.InlineNode) ast.BlockNode { return ast.CreateParaNode(in) }

func setMetadataFromAttributes(m *meta.Meta, a attrs.Attributes) {
	for aKey, aVal := range a {
		if meta.KeyIsValid(aKey) {
			m.Set(aKey, aVal)
		}
	}
}

func (e *evaluator) visitInlineSlice(is *ast.InlineSlice) {
	for i := 0; i < len(*is); i++ {
		in := (*is)[i]
		ast.Walk(e, in)
		switch n := in.(type) {
		case *ast.LinkNode:

func (e *evaluator) evaluateEmbeddedInline(content []byte, syntax string) ast.InlineSlice {
	is := parser.ParseInlines(input.NewInput(content), syntax)
	ast.Walk(e, &is)
	return is
}

func (e *evaluator) evaluateEmbeddedZettel(zettel domain.Zettel) *ast.ZettelNode {
	zn := parser.ParseZettel(zettel, zettel.Meta.GetDefault(api.KeySyntax, ""), e.rtConfig)
	zn := parser.ParseZettel(e.ctx, zettel, zettel.Meta.GetDefault(api.KeySyntax, ""), e.rtConfig)
	ast.Walk(e, &zn.Ast)
	return zn
}

func findInlineSlice(bs *ast.BlockSlice, fragment string) ast.InlineSlice {
	if fragment == "" {
		return firstInlinesToEmbed(*bs)