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

.PHONY:  check api build release clean
.PHONY:  check relcheck api build release clean

check:
	go run tools/build.go check

relcheck:
	go run tools/build.go relcheck

api:
	go run tools/build.go testapi

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

build:

that are related to each other. Since knowledge is typically build up
gradually, one major focus is a long-term store of these notes, hence the name
“Zettelstore”.

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

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

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

[Stay tuned](https://twitter.com/zettelstore)…

0.0.15
0.1.2

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

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

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

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

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

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

// ZettelLinksJSON store all links / connections from one zettel to other.
type ZettelLinksJSON struct {
	ID     string `json:"id"`
	Linked struct {
		Incoming []string `json:"incoming,omitempty"`
		Outgoing []string `json:"outgoing,omitempty"`
		Local    []string `json:"local,omitempty"`
		External []string `json:"external,omitempty"`
		Meta     []string `json:"meta,omitempty"`
	} `json:"linked"`
	Embedded struct {
		Outgoing []string `json:"outgoing,omitempty"`
		Local    []string `json:"local,omitempty"`
		External []string `json:"external,omitempty"`
	} `json:"embedded,omitempty"`
	Cites []string `json:"cites,omitempty"`
}

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

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

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

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

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

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

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

import "fmt"

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

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

// Values for HTTP query parameter.
const (
	QueryKeyDepth    = "depth"
	QueryKeyDir      = "dir"
	QueryKeyEncoding = "_enc"
	QueryKeyLimit    = "_limit"
	QueryKeyNegate   = "_negate"
	QueryKeyOffset   = "_offset"
	QueryKeyOrder    = "_order"
	QueryKeyPart     = "_part"
	QueryKeySearch   = "_s"
	QueryKeySort     = "_sort"
)

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

// Supported encoding values.
const (
	EncodingDJSON  = "djson"
	EncodingHTML   = "html"
	EncodingNative = "native"
	EncodingText   = "text"
	EncodingZMK    = "zmk"
)

var mapEncodingEnum = map[string]EncodingEnum{
	EncodingDJSON:  EncoderDJSON,
	EncodingHTML:   EncoderHTML,
	EncodingNative: EncoderNative,
	EncodingText:   EncoderText,
	EncodingZMK:    EncoderZmk,
}
var mapEnumEncoding = map[EncodingEnum]string{}

func init() {
	for k, v := range mapEncodingEnum {
		mapEnumEncoding[v] = k
	}
}

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

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

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

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

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

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

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

import (
	"net/url"
	"strings"

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

type urlQuery struct{ key, val string }

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

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

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

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

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

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

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

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

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

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

}

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

// Constants for FormatCode
const (
	_               FormatKind = iota
	_                    FormatKind = iota
	FormatItalic               // Italic text.
	FormatEmph                 // Semantically emphasized text.
	FormatEmph                      // Emphasized text.
	FormatBold                 // Bold text.
	FormatStrong               // Semantically strongly emphasized text.
	FormatStrong                    // Strongly emphasized text.
	FormatUnder                // Underlined text.
	FormatInsert               // Inserted text.
	FormatInsert                    // Inserted text.
	FormatStrike               // Text that is no longer relevant or no longer accurate.
	FormatDelete               // Deleted text.
	FormatSuper                // Superscripted text.
	FormatSub                  // SubscriptedText.
	FormatQuote                // Quoted text.
	FormatQuotation            // Quotation text.
	FormatSmall                // Smaller text.
	FormatSpan                 // Generic inline container.
	FormatMonospace            // Monospaced text.
	FormatDelete                    // Deleted text.
	FormatSuper                     // Superscripted text.
	FormatSub                       // SubscriptedText.
	FormatQuote                     // Quoted text.
	FormatQuotation                 // Quotation text.
	FormatSmall                     // Smaller text.
	FormatSpan                      // Generic inline container.
	FormatMonospace                 // Monospaced text.
	FormatEmphDeprecated            // Deprecated kind of emphasized text.
)

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

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

		}
	}
	u, err := url.Parse(s)
	if err != nil {
		return &Reference{URL: nil, Value: s, State: RefStateInvalid}
	}
	if len(u.Scheme)+len(u.Opaque)+len(u.Host) == 0 && u.User == nil {
		if _, err := id.Parse(u.Path); err == nil {
		if _, err = id.Parse(u.Path); err == nil {
			return &Reference{URL: u, Value: s, State: RefStateZettel}
		}
		if u.Path == "" && u.Fragment != "" {
			return &Reference{URL: u, Value: s, State: RefStateSelf}
		}
	}
	return &Reference{URL: u, Value: s, State: RefStateExternal}

	"errors"
	"hash/fnv"
	"io"
	"time"

	"github.com/pascaldekloe/jwt"

	"zettelstore.de/c/api"
	"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"

var ErrOtherKind = errors.New("auth: wrong token kind")

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

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

	now := time.Now().Round(time.Second)
	claims := jwt.Claims{
		Registered: jwt.Registered{

		return auth.TokenData{}, ErrTokenExpired
	}
	ident := claims.Subject
	if ident == "" {
		return auth.TokenData{}, ErrNoIdent
	}
	if zidS, ok := claims.Set["zid"].(string); ok {
		if zid, err := id.Parse(zidS); err == nil {
			if kind, ok := claims.Set["_tk"].(float64); ok {
		if zid, err2 := id.Parse(zidS); err2 == nil {
			if kind, ok2 := claims.Set["_tk"].(float64); ok2 {
				if auth.TokenKind(kind) == k {
					return auth.TokenData{
						Token:   token,
						Now:     now,
						Issued:  claims.Issued.Time(),
						Expires: expires,
						Ident:   ident,

			return meta.UserRoleUnknown
		}
		return meta.UserRoleOwner
	}
	if a.IsOwner(user.Zid) {
		return meta.UserRoleOwner
	}
	if val, ok := user.Get(meta.KeyUserRole); ok {
	if val, ok := user.Get(api.KeyUserRole); ok {
		if ur := meta.GetUserRole(val); ur != meta.UserRoleUnknown {
			return ur
		}
	}
	return meta.UserRoleReader
}

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

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

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

import (
	"zettelstore.de/c/api"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/domain/meta"
)

type defaultPolicy struct {
	manager auth.AuthzManager
}

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

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

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

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

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

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

import (
	"zettelstore.de/c/api"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/config"
	"zettelstore.de/z/domain/meta"
)

type ownerPolicy struct {
	manager    auth.AuthzManager

	return o.userIsOwner(user) || o.userCanCreate(user, newMeta)
}

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

func (o *ownerPolicy) CanRead(user, m *meta.Meta) bool {
	// No need to call o.pre.CanRead(user, meta), because it will always return true.

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

var noChangeUser = []string{
	meta.KeyID,
	meta.KeyRole,
	meta.KeyUserID,
	meta.KeyUserRole,
	api.KeyID,
	api.KeyRole,
	api.KeyUserID,
	api.KeyUserRole,
}

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

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

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

import (
	"fmt"
	"testing"

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

func TestPolicies(t *testing.T) {
	t.Parallel()

}

type testAuthzManager struct {
	readOnly bool
	withAuth bool
}

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

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

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

type authConfig struct{ expert bool }

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

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

func testCreate(t *testing.T, pol auth.Policy, withAuth, readonly bool) {
	t.Helper()

	zettel := newZettel()
	publicZettel := newPublicZettel()
	loginZettel := newLoginZettel()
	ownerZettel := newOwnerZettel()
	expertZettel := newExpertZettel()
	userZettel := newUserZettel()
	writerNew := writer.Clone()
	writerNew.Set(meta.KeyUserRole, owner.GetDefault(meta.KeyUserRole, ""))
	writerNew.Set(api.KeyUserRole, owner.GetDefault(api.KeyUserRole, ""))
	roFalse := newRoFalseZettel()
	roTrue := newRoTrueZettel()
	roReader := newRoReaderZettel()
	roWriter := newRoWriterZettel()
	roOwner := newRoOwnerZettel()
	notAuthNotReadonly := !withAuth && !readonly
	testCases := []struct {

	visZid     = id.Zid(1023)
	userZid    = id.Zid(1025)
)

func newAnon() *meta.Meta { return nil }
func newCreator() *meta.Meta {
	user := meta.New(creatorZid)
	user.Set(meta.KeyTitle, "Creator")
	user.Set(meta.KeyRole, meta.ValueRoleUser)
	user.Set(meta.KeyUserRole, meta.ValueUserRoleCreator)
	user.Set(api.KeyTitle, "Creator")
	user.Set(api.KeyRole, api.ValueRoleUser)
	user.Set(api.KeyUserRole, api.ValueUserRoleCreator)
	return user
}
func newReader() *meta.Meta {
	user := meta.New(readerZid)
	user.Set(meta.KeyTitle, "Reader")
	user.Set(meta.KeyRole, meta.ValueRoleUser)
	user.Set(meta.KeyUserRole, meta.ValueUserRoleReader)
	user.Set(api.KeyTitle, "Reader")
	user.Set(api.KeyRole, api.ValueRoleUser)
	user.Set(api.KeyUserRole, api.ValueUserRoleReader)
	return user
}
func newWriter() *meta.Meta {
	user := meta.New(writerZid)
	user.Set(meta.KeyTitle, "Writer")
	user.Set(meta.KeyRole, meta.ValueRoleUser)
	user.Set(meta.KeyUserRole, meta.ValueUserRoleWriter)
	user.Set(api.KeyTitle, "Writer")
	user.Set(api.KeyRole, api.ValueRoleUser)
	user.Set(api.KeyUserRole, api.ValueUserRoleWriter)
	return user
}
func newOwner() *meta.Meta {
	user := meta.New(ownerZid)
	user.Set(meta.KeyTitle, "Owner")
	user.Set(meta.KeyRole, meta.ValueRoleUser)
	user.Set(meta.KeyUserRole, meta.ValueUserRoleOwner)
	user.Set(api.KeyTitle, "Owner")
	user.Set(api.KeyRole, api.ValueRoleUser)
	user.Set(api.KeyUserRole, api.ValueUserRoleOwner)
	return user
}
func newOwner2() *meta.Meta {
	user := meta.New(owner2Zid)
	user.Set(meta.KeyTitle, "Owner 2")
	user.Set(meta.KeyRole, meta.ValueRoleUser)
	user.Set(meta.KeyUserRole, meta.ValueUserRoleOwner)
	user.Set(api.KeyTitle, "Owner 2")
	user.Set(api.KeyRole, api.ValueRoleUser)
	user.Set(api.KeyUserRole, api.ValueUserRoleOwner)
	return user
}
func newZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(meta.KeyTitle, "Any Zettel")
	m.Set(api.KeyTitle, "Any Zettel")
	return m
}
func newPublicZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Public Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityPublic)
	m.Set(api.KeyTitle, "Public Zettel")
	m.Set(api.KeyVisibility, api.ValueVisibilityPublic)
	return m
}
func newCreatorZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Creator Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityCreator)
	m.Set(api.KeyTitle, "Creator Zettel")
	m.Set(api.KeyVisibility, api.ValueVisibilityCreator)
	return m
}
func newLoginZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Login Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityLogin)
	m.Set(api.KeyTitle, "Login Zettel")
	m.Set(api.KeyVisibility, api.ValueVisibilityLogin)
	return m
}
func newOwnerZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Owner Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityOwner)
	m.Set(api.KeyTitle, "Owner Zettel")
	m.Set(api.KeyVisibility, api.ValueVisibilityOwner)
	return m
}
func newExpertZettel() *meta.Meta {
	m := meta.New(visZid)
	m.Set(meta.KeyTitle, "Expert Zettel")
	m.Set(meta.KeyVisibility, meta.ValueVisibilityExpert)
	m.Set(api.KeyTitle, "Expert Zettel")
	m.Set(api.KeyVisibility, api.ValueVisibilityExpert)
	return m
}
func newRoFalseZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(meta.KeyTitle, "No r/o Zettel")
	m.Set(meta.KeyReadOnly, "false")
	m.Set(api.KeyTitle, "No r/o Zettel")
	m.Set(api.KeyReadOnly, api.ValueFalse)
	return m
}
func newRoTrueZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(meta.KeyTitle, "A r/o Zettel")
	m.Set(meta.KeyReadOnly, "true")
	m.Set(api.KeyTitle, "A r/o Zettel")
	m.Set(api.KeyReadOnly, api.ValueTrue)
	return m
}
func newRoReaderZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(meta.KeyTitle, "Reader r/o Zettel")
	m.Set(meta.KeyReadOnly, meta.ValueUserRoleReader)
	m.Set(api.KeyTitle, "Reader r/o Zettel")
	m.Set(api.KeyReadOnly, api.ValueUserRoleReader)
	return m
}
func newRoWriterZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(meta.KeyTitle, "Writer r/o Zettel")
	m.Set(meta.KeyReadOnly, meta.ValueUserRoleWriter)
	m.Set(api.KeyTitle, "Writer r/o Zettel")
	m.Set(api.KeyReadOnly, api.ValueUserRoleWriter)
	return m
}
func newRoOwnerZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(meta.KeyTitle, "Owner r/o Zettel")
	m.Set(meta.KeyReadOnly, meta.ValueUserRoleOwner)
	m.Set(api.KeyTitle, "Owner r/o Zettel")
	m.Set(api.KeyReadOnly, api.ValueUserRoleOwner)
	return m
}
func newUserZettel() *meta.Meta {
	m := meta.New(userZid)
	m.Set(meta.KeyTitle, "Any User")
	m.Set(meta.KeyRole, meta.ValueRoleUser)
	m.Set(api.KeyTitle, "Any User")
	m.Set(api.KeyRole, api.ValueRoleUser)
	return m
}

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

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

// BaseBox is implemented by all Zettel boxes.

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

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

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

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

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

import (
	"context"
	"net/url"

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

	number   int
	enricher box.Enricher
}

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

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

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

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

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

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

import (
	"strings"
	"bytes"

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

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

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

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

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

import (
	"bytes"
	"fmt"
	"strings"

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

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

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

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

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

import (
	"bytes"
	"fmt"
	"strings"

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

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

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

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

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

import (
	"fmt"

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

func getVersionMeta(zid id.Zid, title string) *meta.Meta {
	m := meta.New(zid)
	m.Set(meta.KeyTitle, title)
	m.Set(meta.KeyVisibility, meta.ValueVisibilityExpert)
	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(meta.KeyVisibility, meta.ValueVisibilityPublic)
	m.Set(api.KeyVisibility, api.ValueVisibilityPublic)
	return m
}
func genVersionBuildC(*meta.Meta) string {
	return kernel.Main.GetConfig(kernel.CoreService, kernel.CoreVersion).(string)
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")
}
func genVersionHostC(*meta.Meta) string {
	return kernel.Main.GetConfig(kernel.CoreService, kernel.CoreHostname).(string)
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")
}
func genVersionOSC(*meta.Meta) string {
func genVersionOSC(*meta.Meta) []byte {
	return fmt.Sprintf(
		"%v/%v",
		kernel.Main.GetConfig(kernel.CoreService, kernel.CoreGoOS).(string),
		kernel.Main.GetConfig(kernel.CoreService, kernel.CoreGoArch).(string),
	goOS := kernel.Main.GetConfig(kernel.CoreService, kernel.CoreGoOS).(string)
	goArch := kernel.Main.GetConfig(kernel.CoreService, kernel.CoreGoArch).(string)
	)
	result := make([]byte, 0, len(goOS)+len(goArch)+1)
	result = append(result, goOS...)
	result = append(result, '/')
	return append(result, goArch...)
}

*,*::before,*::after {
    box-sizing: border-box;
  }
  html {
    font-size: 1rem;
    font-family: serif;
    scroll-behavior: smooth;
    height: 100%;
  }
  body {
    margin: 0;
    min-height: 100vh;
    text-rendering: optimizeSpeed;
    line-height: 1.4;
    overflow-x: hidden;
    background-color: #f8f8f8 ;
    height: 100%;
  }
  nav.zs-menu {
    background-color: hsl(210, 28%, 90%);
    overflow: auto;
    white-space: nowrap;

  span.zs-indication {
    border: 1px solid black;
    border-radius: .25rem;
    padding: .1rem .2rem;
    font-size: 95%;
  }
  .zs-example { border-style: dotted !important }
  .zs-info {
    background-color: lightblue;
    padding: .5rem 1rem;
  }
  .zs-warning {
    background-color: lightyellow;
    padding: .5rem 1rem;
  }
  .zs-error {
    background-color: lightpink;
    border-style: none !important;
    font-weight: bold;
  }
  .zs-ta-left { text-align:left }
  .zs-ta-center { text-align:center }
  .zs-ta-right { text-align:right }
  .zs-monospace { font-family:monospace }
  .zs-font-size-0 { font-size:75% }
  .zs-font-size-1 { font-size:83% }
  .zs-font-size-2 { font-size:100% }
  .zs-font-size-3 { font-size:117% }
  .zs-font-size-4 { font-size:150% }
  .zs-font-size-5 { font-size:200% }
  .zs-deprecated { border-style: dashed; padding: .2rem }
  kbd {
    background: hsl(210, 5%, 100%);
    border: 1px solid hsl(210, 5%, 70%);
    border-radius: .25rem;
    padding: .1rem .2rem;
    font-size: 75%;
  }

<!DOCTYPE html>
<html{{#Lang}} lang="{{Lang}}"{{/Lang}}>
<head>
<meta charset="utf-8">
<meta name="referrer" content="no-referrer">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="generator" content="Zettelstore">
<meta name="format-detection" content="telephone=no">
{{{MetaHeader}}}
<link rel="stylesheet" href="{{{CSSBaseURL}}}">
<link rel="stylesheet" href="{{{CSSUserURL}}}">
<title>{{Title}}</title>

{{{Content}}}
</main>
{{#FooterHTML}}
<footer>
{{{FooterHTML}}}
</footer>
{{/FooterHTML}}
</body>
</html>

package constbox

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

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

}

const syntaxTemplate = "mustache"

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

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

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

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

//go:embed base.mustache
var contentBaseMustache string
var contentBaseMustache []byte

//go:embed login.mustache
var contentLoginMustache string
var contentLoginMustache []byte

//go:embed zettel.mustache
var contentZettelMustache string
var contentZettelMustache []byte

//go:embed info.mustache
var contentInfoMustache string
var contentInfoMustache []byte

//go:embed context.mustache
var contentContextMustache string
var contentContextMustache []byte

//go:embed form.mustache
var contentFormMustache string
var contentFormMustache []byte

//go:embed rename.mustache
var contentRenameMustache string
var contentRenameMustache []byte

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

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

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

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

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

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

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

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

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

<article>
<header>
<h1>Delete Zettel {{Zid}}</h1>
</header>
<p>Do you really want to delete this zettel?</p>
{{#HasShadows}}
<div class="zs-info">
<h2>Infomation</h2>
<p>If you delete this zettel, the previoulsy shadowed zettel from overlayed box {{ShadowedBox}} becomes available.</p>
</div>
{{/HasShadows}}
{{#HasIncoming}}
<div class="zs-warning">
<h2>Warning!</h2>
<p>If you delete this zettel, incoming references from the following zettel will become invalid.</p>
<ul>
{{#Incoming}}
<li><a href="{{{URL}}}">{{Text}}</a></li>
{{/Incoming}}
</ul>
</div>
{{/HasIncoming}}
<dl>
{{#MetaPairs}}
<dt>{{Key}}:</dt><dd>{{Value}}</dd>
{{/MetaPairs}}
</dl>
<form method="POST">
<input class="zs-button" type="submit" value="Delete">

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

<article>
<header>
<h1>Rename Zettel {{.Zid}}</h1>
</header>
<p>Do you really want to rename this zettel?</p>
{{#HasIncoming}}
<div class="zs-warning">
<h2>Warning!</h2>
<p>If you rename this zettel, incoming references from the following zettel will become invalid.</p>
<ul>
{{#Incoming}}
<li><a href="{{{URL}}}">{{Text}}</a></li>
{{/Incoming}}
</ul>
</div>
{{/HasIncoming}}
<form method="POST">
<div>
<label for="newid">New zettel id</label>
<input class="zs-input" type="text" id="newzid" name="newzid" placeholder="ZID.." value="{{Zid}}" autofocus>
</div>
<input type="hidden" id="curzid" name="curzid" value="{{Zid}}">
<input class="zs-button" type="submit" value="Rename">

	"os"
	"path/filepath"
	"strconv"
	"strings"
	"sync"
	"time"

	"zettelstore.de/c/api"
	"zettelstore.de/z/box"
	"zettelstore.de/z/box/dirbox/directory"
	"zettelstore.de/z/box/filebox"
	"zettelstore.de/z/box/manager"
	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"

	return p[0 : len(p)-len(filepath.Ext(p))]
}

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

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

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

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

	cmd.rc <- resGetMeta{m, err}
}

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

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

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

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

	entry := cmd.entry
	switch entry.MetaSpec {
	case directory.MetaSpecFile:
		m, err = parseMetaFile(entry.Zid, entry.MetaPath)
		if err == nil {

		panic("TODO: ???")
	}
	cmd.rc <- err
}

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

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

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

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

func cmdCleanupMeta(m *meta.Meta, entry *directory.Entry) {

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

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

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

func (ss *simpleService) GetEntries() ([]*directory.Entry, error) {
	ss.mx.Lock()
	defer ss.mx.Unlock()
	entrySet, err := ss.getEntries()
	entrySet, err := ss.doGetEntries()
	if err != nil {
		return nil, err
	}
	result := make([]*directory.Entry, 0, len(entrySet))
	for _, entry := range entrySet {
		result = append(result, entry)
	}
	return result, nil
}

func (ss *simpleService) getEntries() (map[id.Zid]*directory.Entry, error) {
func (ss *simpleService) doGetEntries() (map[id.Zid]*directory.Entry, error) {
	dirEntries, err := os.ReadDir(ss.dirPath)
	if err != nil {
		return nil, err
	}
	entrySet := make(map[id.Zid]*directory.Entry)
	for _, dirEntry := range dirEntries {
		if dirEntry.IsDir() {
			continue
		}
		if info, err1 := dirEntry.Info(); err1 != nil || !info.Mode().IsRegular() {
			continue
		}
		name := dirEntry.Name()
		match := matchValidFileName(name)
		if len(match) == 0 {
			continue
		}
		zid, err := id.Parse(match[1])
		if err != nil {
		zid, err2 := id.Parse(match[1])
		if err2 != nil {
			continue
		}
		var entry *directory.Entry
		if e, ok := entrySet[zid]; ok {
			entry = e
		} else {
			entry = &directory.Entry{Zid: zid}

		entry.ContentExt = ext
	}
}

func (ss *simpleService) GetEntry(zid id.Zid) (*directory.Entry, error) {
	ss.mx.Lock()
	defer ss.mx.Unlock()
	return ss.getEntry(zid)
	return ss.doGetEntry(zid)
}

func (ss *simpleService) getEntry(zid id.Zid) (*directory.Entry, error) {
func (ss *simpleService) doGetEntry(zid id.Zid) (*directory.Entry, error) {
	pattern := filepath.Join(ss.dirPath, zid.String()) + "*.*"
	paths, err := filepath.Glob(pattern)
	if err != nil {
		return nil, err
	}
	if len(paths) == 0 {
		return nil, nil

	return entry, nil
}

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

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

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

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

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

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

func init() {

	}
	return ext
}

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

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

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

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

	defer reader.Close()
	zp.zettel = make(map[id.Zid]*zipEntry)
	for _, f := range reader.File {
		match := matchValidFileName(f.Name)
		if len(match) < 1 {
			continue
		}
		zid, err := id.Parse(match[1])
		if err != nil {
		zid, err2 := id.Parse(match[1])
		if err2 != nil {
			continue
		}
		zp.addFile(zid, f.Name, match[3])
	}
	return nil
}

	reader, err := zip.OpenReader(zp.name)
	if err != nil {
		return domain.Zettel{}, err
	}
	defer reader.Close()

	var m *meta.Meta
	var src string
	var src []byte
	var inMeta bool
	if entry.metaInHeader {
		src, err = readZipFileContent(reader, entry.contentName)
		if err != nil {
			return domain.Zettel{}, err
		}
		inp := input.NewInput(src)

func (zp *zipBox) ApplyMeta(ctx context.Context, handle box.MetaFunc) error {
	reader, err := zip.OpenReader(zp.name)
	if err != nil {
		return err
	}
	defer reader.Close()
	for zid, entry := range zp.zettel {
		m, err := readZipMeta(reader, zid, entry)
		if err != nil {
		m, err2 := readZipMeta(reader, zid, entry)
		if err2 != nil {
			continue
		}
		zp.enricher.Enrich(ctx, m, zp.number)
		handle(m)
	}
	return nil
}

	if err != nil {
		return nil, err
	}
	inp := input.NewInput(src)
	return meta.NewFromInput(zid, inp), nil
}

func readZipFileContent(reader *zip.ReadCloser, name string) (string, error) {
func readZipFileContent(reader *zip.ReadCloser, name string) ([]byte, error) {
	f, err := reader.Open(name)
	if err != nil {
		return "", err
		return nil, err
	}
	defer f.Close()
	buf, err := io.ReadAll(f)
	return io.ReadAll(f)
	if err != nil {
		return "", err
	}
}
	return string(buf), nil
}

	ar.Enqueue(id.Zid(3), arUpdate)
	if ar.first == ar.last {
		t.Errorf("Expected more than one room, but got only one")
	}

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

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

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

import (
	"bytes"
	"context"
	"errors"
	"strings"

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

// Conatains all box.Box related functions

// Location returns some information where the box is located.
func (mgr *Manager) Location() string {
	if len(mgr.boxes) <= 2 {
		return "NONE"
	}
	var sb strings.Builder
	var buf bytes.Buffer
	for i := 0; i < len(mgr.boxes)-2; i++ {
		if i > 0 {
			sb.WriteString(", ")
			buf.WriteString(", ")
		}
		sb.WriteString(mgr.boxes[i].Location())
		buf.WriteString(mgr.boxes[i].Location())
	}
	return sb.String()
	return buf.String()
}

// CanCreateZettel returns true, if box could possibly create a new zettel.
func (mgr *Manager) CanCreateZettel(ctx context.Context) bool {
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	return mgr.started && mgr.boxes[0].CanCreateZettel(ctx)

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

import (
	"context"
	"strconv"

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

// Enrich computes additional properties and updates the given metadata.
func (mgr *Manager) Enrich(ctx context.Context, m *meta.Meta, boxNumber int) {
	if box.DoNotEnrich(ctx) {
		// Enrich is called indirectly via indexer or enrichment is not requested
		// because of other reasons -> ignore this call, do not update meta data
		return
	}
	m.Set(meta.KeyBoxNumber, strconv.Itoa(boxNumber))
	m.Set(api.KeyBoxNumber, strconv.Itoa(boxNumber))
	computePublished(m)
	mgr.idxStore.Enrich(ctx, m)
}

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

package manager

import (
	"context"
	"net/url"
	"time"

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

		return false
	}
	return true
}

func (mgr *Manager) idxUpdateZettel(ctx context.Context, zettel domain.Zettel) {
	m := zettel.Meta
	if m.GetBool(meta.KeyNoIndex) {
	if m.GetBool(api.KeyNoIndex) {
		// Zettel maybe in index
		toCheck := mgr.idxStore.DeleteZettel(ctx, m.Zid)
		mgr.idxCheckZettel(toCheck)
		return
	}

	var cData collectData

}

func (mgr *Manager) idxUpdateValue(ctx context.Context, inverseKey, value string, zi *store.ZettelIndex) {
	zid, err := id.Parse(value)
	if err != nil {
		return
	}
	if _, err := mgr.GetMeta(ctx, zid); err != nil {
	if _, err = mgr.GetMeta(ctx, zid); err != nil {
		zi.AddDeadRef(zid)
		return
	}
	if inverseKey == "" {
		zi.AddBackRef(zid)
		return
	}

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

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

	"zettelstore.de/z/auth"
	"zettelstore.de/z/box"

type createFunc func(*url.URL, *ConnectData) (box.ManagedBox, error)

var registry = map[string]createFunc{}

// Register the encoder for later retrieval.
func Register(scheme string, create createFunc) {
	if _, ok := registry[scheme]; ok {
		log.Fatalf("Box with scheme %q already registered", scheme)
		panic(scheme)
	}
	registry[scheme] = create
}

// GetSchemes returns all registered scheme, ordered by scheme string.
func GetSchemes() []string {
	result := make([]string, 0, len(registry))

			continue
		}
		err := ssi.Start(ctx)
		if err == nil {
			continue
		}
		for j := i + 1; j < len(mgr.boxes); j++ {
			if ssj, ok := mgr.boxes[j].(box.StartStopper); ok {
			if ssj, ok2 := mgr.boxes[j].(box.StartStopper); ok2 {
				ssj.Stop(ctx)
			}
		}
		mgr.mgrMx.Unlock()
		return err
	}
	mgr.idxAr.Reset() // Ensure an initial index run

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

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

type metaRefs struct {
	forward  id.Slice

	defer ms.mx.RUnlock()
	zi, ok := ms.idx[m.Zid]
	if !ok {
		return false
	}
	var updated bool
	if len(zi.dead) > 0 {
		m.Set(meta.KeyDead, zi.dead.String())
		m.Set(api.KeyDead, zi.dead.String())
		updated = true
	}
	back := removeOtherMetaRefs(m, zi.backward.Copy())
	if len(zi.backward) > 0 {
		m.Set(meta.KeyBackward, zi.backward.String())
		m.Set(api.KeyBackward, zi.backward.String())
		updated = true
	}
	if len(zi.forward) > 0 {
		m.Set(meta.KeyForward, zi.forward.String())
		m.Set(api.KeyForward, zi.forward.String())
		back = remRefs(back, zi.forward)
		updated = true
	}
	if len(zi.meta) > 0 {
		for k, refs := range zi.meta {
			if len(refs.backward) > 0 {
				m.Set(k, refs.backward.String())
				back = remRefs(back, refs.backward)
				updated = true
	for k, refs := range zi.meta {
		if len(refs.backward) > 0 {
			m.Set(k, refs.backward.String())
			back = remRefs(back, refs.backward)
			updated = true
			}
		}
	}
	if len(back) > 0 {
		m.Set(meta.KeyBack, back.String())
		m.Set(api.KeyBack, back.String())
		updated = true
	}
	if zi.itags != "" {
		if tags, ok := m.Get(meta.KeyTags); ok {
			m.Set(meta.KeyAllTags, tags+" "+zi.itags)
	if itags := zi.itags; itags != "" {
		m.Set(api.KeyContentTags, itags)
		if tags, ok2 := m.Get(api.KeyTags); ok2 {
			m.Set(api.KeyAllTags, tags+" "+itags)
		} else {
			m.Set(meta.KeyAllTags, zi.itags)
			m.Set(api.KeyAllTags, itags)
		}
		updated = true
	} else if tags, ok := m.Get(meta.KeyTags); ok {
		m.Set(meta.KeyAllTags, tags)
	} else if tags, ok2 := m.Get(api.KeyTags); ok2 {
		m.Set(api.KeyAllTags, tags)
		updated = true
	}
	return updated
}

// SearchEqual returns all zettel that contains the given exact word.
// The word must be normalized through Unicode NKFD, trimmed and not empty.

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

// Package client provides a client for accessing the Zettelstore via its API.
package client

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"io"
	"net"
	"net/http"
	"net/url"
	"strconv"
	"strings"
	"time"

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

// Client contains all data to execute requests.
type Client struct {
	baseURL   string
	username  string
	password  string
	token     string
	tokenType string
	expires   time.Time
	client    http.Client
}

// NewClient create a new client.
func NewClient(baseURL string) *Client {
	if !strings.HasSuffix(baseURL, "/") {
		baseURL += "/"
	}
	c := Client{
		baseURL: baseURL,
		client: http.Client{
			Timeout: 10 * time.Second,
			Transport: &http.Transport{
				DialContext: (&net.Dialer{
					Timeout: 5 * time.Second, // TCP connect timeout
				}).DialContext,
				TLSHandshakeTimeout: 5 * time.Second,
			},
		},
	}
	return &c
}

func (c *Client) newURLBuilder(key byte) *api.URLBuilder {
	return api.NewURLBuilder(c.baseURL, key)
}
func (*Client) newRequest(ctx context.Context, method string, ub *api.URLBuilder, body io.Reader) (*http.Request, error) {
	return http.NewRequestWithContext(ctx, method, ub.String(), body)
}

func (c *Client) executeRequest(req *http.Request) (*http.Response, error) {
	if c.token != "" {
		req.Header.Add("Authorization", c.tokenType+" "+c.token)
	}
	resp, err := c.client.Do(req)
	if err != nil {
		if resp != nil && resp.Body != nil {
			resp.Body.Close()
		}
		return nil, err
	}
	return resp, err
}

func (c *Client) buildAndExecuteRequest(
	ctx context.Context, method string, ub *api.URLBuilder, body io.Reader, h http.Header) (*http.Response, error) {
	req, err := c.newRequest(ctx, method, ub, body)
	if err != nil {
		return nil, err
	}
	err = c.updateToken(ctx)
	if err != nil {
		return nil, err
	}
	for key, val := range h {
		req.Header[key] = append(req.Header[key], val...)
	}
	return c.executeRequest(req)
}

// SetAuth sets authentication data.
func (c *Client) SetAuth(username, password string) {
	c.username = username
	c.password = password
	c.token = ""
	c.tokenType = ""
	c.expires = time.Time{}
}

func (c *Client) executeAuthRequest(req *http.Request) error {
	resp, err := c.executeRequest(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return errors.New(resp.Status)
	}
	dec := json.NewDecoder(resp.Body)
	var tinfo api.AuthJSON
	err = dec.Decode(&tinfo)
	if err != nil {
		return err
	}
	c.token = tinfo.Token
	c.tokenType = tinfo.Type
	c.expires = time.Now().Add(time.Duration(tinfo.Expires*10/9) * time.Second)
	return nil
}

func (c *Client) updateToken(ctx context.Context) error {
	if c.username == "" {
		return nil
	}
	if time.Now().After(c.expires) {
		return c.Authenticate(ctx)
	}
	return c.RefreshToken(ctx)
}

// Authenticate sets a new token by sending user name and password.
func (c *Client) Authenticate(ctx context.Context) error {
	authData := url.Values{"username": {c.username}, "password": {c.password}}
	req, err := c.newRequest(ctx, http.MethodPost, c.newURLBuilder('a'), strings.NewReader(authData.Encode()))
	if err != nil {
		return err
	}
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	return c.executeAuthRequest(req)
}

// RefreshToken updates the access token
func (c *Client) RefreshToken(ctx context.Context) error {
	req, err := c.newRequest(ctx, http.MethodPut, c.newURLBuilder('a'), nil)
	if err != nil {
		return err
	}
	return c.executeAuthRequest(req)
}

// CreateZettel creates a new zettel and returns its URL.
func (c *Client) CreateZettel(ctx context.Context, data string) (id.Zid, error) {
	ub := c.jsonZettelURLBuilder('z', nil)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodPost, ub, strings.NewReader(data), nil)
	if err != nil {
		return id.Invalid, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusCreated {
		return id.Invalid, errors.New(resp.Status)
	}
	b, err := io.ReadAll(resp.Body)
	if err != nil {
		return id.Invalid, err
	}
	zid, err := id.Parse(string(b))
	if err != nil {
		return id.Invalid, err
	}
	return zid, nil
}

// CreateZettelJSON creates a new zettel and returns its URL.
func (c *Client) CreateZettelJSON(ctx context.Context, data *api.ZettelDataJSON) (id.Zid, error) {
	var buf bytes.Buffer
	if err := encodeZettelData(&buf, data); err != nil {
		return id.Invalid, err
	}
	ub := c.jsonZettelURLBuilder('j', nil)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodPost, ub, &buf, nil)
	if err != nil {
		return id.Invalid, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusCreated {
		return id.Invalid, errors.New(resp.Status)
	}
	dec := json.NewDecoder(resp.Body)
	var newZid api.ZidJSON
	err = dec.Decode(&newZid)
	if err != nil {
		return id.Invalid, err
	}
	zid, err := id.Parse(newZid.ID)
	if err != nil {
		return id.Invalid, err
	}
	return zid, nil
}

func encodeZettelData(buf *bytes.Buffer, data *api.ZettelDataJSON) error {
	enc := json.NewEncoder(buf)
	enc.SetEscapeHTML(false)
	return enc.Encode(&data)
}

// ListZettel returns a list of all Zettel.
func (c *Client) ListZettel(ctx context.Context, query url.Values) (string, error) {
	ub := c.jsonZettelURLBuilder('z', query)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return "", errors.New(resp.Status)
	}
	data, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", err
	}
	return string(data), nil
}

// ListZettelJSON returns a list of all Zettel.
func (c *Client) ListZettelJSON(ctx context.Context, query url.Values) ([]api.ZidMetaJSON, error) {
	ub := c.jsonZettelURLBuilder('j', query)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, errors.New(resp.Status)
	}
	dec := json.NewDecoder(resp.Body)
	var zl api.ZettelListJSON
	err = dec.Decode(&zl)
	if err != nil {
		return nil, err
	}
	return zl.List, nil
}

// GetZettel returns a zettel as a string.
func (c *Client) GetZettel(ctx context.Context, zid id.Zid, part string) (string, error) {
	ub := c.jsonZettelURLBuilder('z', nil).SetZid(zid)
	if part != "" && part != api.PartContent {
		ub.AppendQuery(api.QueryKeyPart, part)
	}
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return "", errors.New(resp.Status)
	}
	data, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", err
	}
	return string(data), nil
}

// GetZettelJSON returns a zettel as a JSON struct.
func (c *Client) GetZettelJSON(ctx context.Context, zid id.Zid) (*api.ZettelDataJSON, error) {
	ub := c.jsonZettelURLBuilder('j', nil).SetZid(zid)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, errors.New(resp.Status)
	}
	dec := json.NewDecoder(resp.Body)
	var out api.ZettelDataJSON
	err = dec.Decode(&out)
	if err != nil {
		return nil, err
	}
	return &out, nil
}

// GetParsedZettel return a parsed zettel in a defined encoding.
func (c *Client) GetParsedZettel(ctx context.Context, zid id.Zid, enc api.EncodingEnum) (string, error) {
	return c.getZettelString(ctx, 'p', zid, enc)
}

// GetEvaluatedZettel return an evaluated zettel in a defined encoding.
func (c *Client) GetEvaluatedZettel(ctx context.Context, zid id.Zid, enc api.EncodingEnum) (string, error) {
	return c.getZettelString(ctx, 'v', zid, enc)
}

func (c *Client) getZettelString(ctx context.Context, key byte, zid id.Zid, enc api.EncodingEnum) (string, error) {
	ub := c.jsonZettelURLBuilder(key, nil).SetZid(zid)
	ub.AppendQuery(api.QueryKeyEncoding, enc.String())
	ub.AppendQuery(api.QueryKeyPart, api.PartContent)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return "", errors.New(resp.Status)
	}
	content, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", err
	}
	return string(content), nil
}

// GetZettelOrder returns metadata of the given zettel and, more important,
// metadata of zettel that are referenced in a list within the first zettel.
func (c *Client) GetZettelOrder(ctx context.Context, zid id.Zid) (*api.ZidMetaRelatedList, error) {
	ub := c.newURLBuilder('o').SetZid(zid)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, errors.New(resp.Status)
	}
	dec := json.NewDecoder(resp.Body)
	var out api.ZidMetaRelatedList
	err = dec.Decode(&out)
	if err != nil {
		return nil, err
	}
	return &out, nil
}

// ContextDirection specifies how the context should be calculated.
type ContextDirection uint8

// Allowed values for ContextDirection
const (
	_ ContextDirection = iota
	DirBoth
	DirBackward
	DirForward
)

// GetZettelContext returns metadata of the given zettel and, more important,
// metadata of zettel that for the context of the first zettel.
func (c *Client) GetZettelContext(
	ctx context.Context, zid id.Zid, dir ContextDirection, depth, limit int) (
	*api.ZidMetaRelatedList, error,
) {
	ub := c.newURLBuilder('x').SetZid(zid)
	switch dir {
	case DirBackward:
		ub.AppendQuery(api.QueryKeyDir, api.DirBackward)
	case DirForward:
		ub.AppendQuery(api.QueryKeyDir, api.DirForward)
	}
	if depth > 0 {
		ub.AppendQuery(api.QueryKeyDepth, strconv.Itoa(depth))
	}
	if limit > 0 {
		ub.AppendQuery(api.QueryKeyLimit, strconv.Itoa(limit))
	}
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, errors.New(resp.Status)
	}
	dec := json.NewDecoder(resp.Body)
	var out api.ZidMetaRelatedList
	err = dec.Decode(&out)
	if err != nil {
		return nil, err
	}
	return &out, nil
}

// GetZettelLinks returns connections to other zettel, embedded material, externals URLs.
func (c *Client) GetZettelLinks(ctx context.Context, zid id.Zid) (*api.ZettelLinksJSON, error) {
	ub := c.newURLBuilder('l').SetZid(zid)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, errors.New(resp.Status)
	}
	dec := json.NewDecoder(resp.Body)
	var out api.ZettelLinksJSON
	err = dec.Decode(&out)
	if err != nil {
		return nil, err
	}
	return &out, nil
}

// UpdateZettel updates an existing zettel.
func (c *Client) UpdateZettel(ctx context.Context, zid id.Zid, data string) error {
	ub := c.jsonZettelURLBuilder('z', nil).SetZid(zid)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodPut, ub, strings.NewReader(data), nil)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNoContent {
		return errors.New(resp.Status)
	}
	return nil
}

// UpdateZettelJSON updates an existing zettel.
func (c *Client) UpdateZettelJSON(ctx context.Context, zid id.Zid, data *api.ZettelDataJSON) error {
	var buf bytes.Buffer
	if err := encodeZettelData(&buf, data); err != nil {
		return err
	}
	ub := c.jsonZettelURLBuilder('j', nil).SetZid(zid)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodPut, ub, &buf, nil)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNoContent {
		return errors.New(resp.Status)
	}
	return nil
}

// RenameZettel renames a zettel.
func (c *Client) RenameZettel(ctx context.Context, oldZid, newZid id.Zid) error {
	ub := c.jsonZettelURLBuilder('z', nil).SetZid(oldZid)
	h := http.Header{
		api.HeaderDestination: {c.jsonZettelURLBuilder('z', nil).SetZid(newZid).String()},
	}
	resp, err := c.buildAndExecuteRequest(ctx, api.MethodMove, ub, nil, h)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNoContent {
		return errors.New(resp.Status)
	}
	return nil
}

// DeleteZettel deletes a zettel with the given identifier.
func (c *Client) DeleteZettel(ctx context.Context, zid id.Zid) error {
	ub := c.jsonZettelURLBuilder('z', nil).SetZid(zid)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodDelete, ub, nil, nil)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNoContent {
		return errors.New(resp.Status)
	}
	return nil
}

func (c *Client) jsonZettelURLBuilder(key byte, query url.Values) *api.URLBuilder {
	ub := c.newURLBuilder(key)
	for key, values := range query {
		if key == api.QueryKeyEncoding {
			continue
		}
		for _, val := range values {
			ub.AppendQuery(key, val)
		}
	}
	return ub
}

// ListTags returns a map of all tags, together with the associated zettel containing this tag.
func (c *Client) ListTags(ctx context.Context) (map[string][]string, error) {
	err := c.updateToken(ctx)
	if err != nil {
		return nil, err
	}
	req, err := c.newRequest(ctx, http.MethodGet, c.newURLBuilder('t'), nil)
	if err != nil {
		return nil, err
	}
	resp, err := c.executeRequest(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, errors.New(resp.Status)
	}
	dec := json.NewDecoder(resp.Body)
	var tl api.TagListJSON
	err = dec.Decode(&tl)
	if err != nil {
		return nil, err
	}
	return tl.Tags, nil
}

// ListRoles returns a list of all roles.
func (c *Client) ListRoles(ctx context.Context) ([]string, error) {
	err := c.updateToken(ctx)
	if err != nil {
		return nil, err
	}
	req, err := c.newRequest(ctx, http.MethodGet, c.newURLBuilder('r'), nil)
	if err != nil {
		return nil, err
	}
	resp, err := c.executeRequest(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, errors.New(resp.Status)
	}
	dec := json.NewDecoder(resp.Body)
	var rl api.RoleListJSON
	err = dec.Decode(&rl)
	if err != nil {
		return nil, err
	}
	return rl.Roles, nil
}

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

// Package client provides a client for accessing the Zettelstore via its API.
package client_test

import (
	"context"
	"flag"
	"fmt"
	"net/url"
	"strings"
	"testing"

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

func TestCreateGetRenameDeleteZettel(t *testing.T) {
	// Is not to be allowed to run in parallel with other tests.
	zettel := `title: A Test

Example content.`
	c := getClient()
	c.SetAuth("owner", "owner")
	zid, err := c.CreateZettel(context.Background(), zettel)
	if err != nil {
		t.Error("Cannot create zettel:", err)
		return
	}
	if !zid.IsValid() {
		t.Error("Invalid zettel ID", zid)
		return
	}
	data, err := c.GetZettel(context.Background(), zid, api.PartZettel)
	if err != nil {
		t.Error("Cannot read zettel", zid, err)
		return
	}
	exp := `title: A Test
role: zettel
syntax: zmk

Example content.`
	if data != exp {
		t.Errorf("Expected zettel data: %q, but got %q", exp, data)
	}
	newZid := zid + 1
	err = c.RenameZettel(context.Background(), zid, newZid)
	if err != nil {
		t.Error("Cannot rename", zid, ":", err)
		newZid = zid
	}
	err = c.DeleteZettel(context.Background(), newZid)
	if err != nil {
		t.Error("Cannot delete", zid, ":", err)
		return
	}
}

func TestCreateRenameDeleteZettelJSON(t *testing.T) {
	// Is not to be allowed to run in parallel with other tests.
	c := getClient()
	c.SetAuth("creator", "creator")
	zid, err := c.CreateZettelJSON(context.Background(), &api.ZettelDataJSON{
		Meta:     nil,
		Encoding: "",
		Content:  "Example",
	})
	if err != nil {
		t.Error("Cannot create zettel:", err)
		return
	}
	if !zid.IsValid() {
		t.Error("Invalid zettel ID", zid)
		return
	}
	newZid := zid + 1
	c.SetAuth("owner", "owner")
	err = c.RenameZettel(context.Background(), zid, newZid)
	if err != nil {
		t.Error("Cannot rename", zid, ":", err)
		newZid = zid
	}
	err = c.DeleteZettel(context.Background(), newZid)
	if err != nil {
		t.Error("Cannot delete", zid, ":", err)
		return
	}
}

func TestUpdateZettel(t *testing.T) {
	t.Parallel()
	c := getClient()
	c.SetAuth("owner", "owner")
	z, err := c.GetZettel(context.Background(), id.DefaultHomeZid, api.PartZettel)
	if err != nil {
		t.Error(err)
		return
	}
	if !strings.HasPrefix(z, "title: Home\n") {
		t.Error("Got unexpected zettel", z)
		return
	}
	newZettel := `title: New Home
role: zettel
syntax: zmk

Empty`
	err = c.UpdateZettel(context.Background(), id.DefaultHomeZid, newZettel)
	if err != nil {
		t.Error(err)
		return
	}
	zt, err := c.GetZettel(context.Background(), id.DefaultHomeZid, api.PartZettel)
	if err != nil {
		t.Error(err)
		return
	}
	if zt != newZettel {
		t.Errorf("Expected zettel %q, got %q", newZettel, zt)
	}
	// Must delete to clean up for next tests
	err = c.DeleteZettel(context.Background(), id.DefaultHomeZid)
	if err != nil {
		t.Error("Cannot delete", id.DefaultHomeZid, ":", err)
		return
	}
}

func TestUpdateZettelJSON(t *testing.T) {
	t.Parallel()
	c := getClient()
	c.SetAuth("writer", "writer")
	z, err := c.GetZettelJSON(context.Background(), id.DefaultHomeZid)
	if err != nil {
		t.Error(err)
		return
	}
	if got := z.Meta[meta.KeyTitle]; got != "Home" {
		t.Errorf("Title of zettel is not \"Home\", but %q", got)
		return
	}
	newTitle := "New Home"
	z.Meta[meta.KeyTitle] = newTitle
	err = c.UpdateZettelJSON(context.Background(), id.DefaultHomeZid, z)
	if err != nil {
		t.Error(err)
		return
	}
	zt, err := c.GetZettelJSON(context.Background(), id.DefaultHomeZid)
	if err != nil {
		t.Error(err)
		return
	}
	if got := zt.Meta[meta.KeyTitle]; got != newTitle {
		t.Errorf("Title of zettel is not %q, but %q", newTitle, got)
	}
	// No need to clean up, because we just changed the title.
}

func TestListZettel(t *testing.T) {
	testdata := []struct {
		user string
		exp  int
	}{
		{"", 7},
		{"creator", 10},
		{"reader", 12},
		{"writer", 12},
		{"owner", 34},
	}

	t.Parallel()
	c := getClient()
	query := url.Values{api.QueryKeyEncoding: {api.EncodingHTML}} // Client must remove "html"
	for i, tc := range testdata {
		t.Run(fmt.Sprintf("User %d/%q", i, tc.user), func(tt *testing.T) {
			c.SetAuth(tc.user, tc.user)
			l, err := c.ListZettelJSON(context.Background(), query)
			if err != nil {
				tt.Error(err)
				return
			}
			got := len(l)
			if got != tc.exp {
				tt.Errorf("List of length %d expected, but got %d\n%v", tc.exp, got, l)
			}
		})
	}
	l, err := c.ListZettelJSON(context.Background(), url.Values{meta.KeyRole: {meta.ValueRoleConfiguration}})
	if err != nil {
		t.Error(err)
		return
	}
	got := len(l)
	if got != 27 {
		t.Errorf("List of length %d expected, but got %d\n%v", 27, got, l)
	}

	pl, err := c.ListZettel(context.Background(), url.Values{meta.KeyRole: {meta.ValueRoleConfiguration}})
	if err != nil {
		t.Error(err)
		return
	}
	lines := strings.Split(pl, "\n")
	if lines[len(lines)-1] == "" {
		lines = lines[:len(lines)-1]
	}
	if len(lines) != len(l) {
		t.Errorf("Different list lenght: Plain=%d, JSON=%d", len(lines), len(l))
	} else {
		for i, line := range lines {
			if got := line[:14]; got != l[i].ID {
				t.Errorf("%d: JSON=%q, got=%q", i, l[i].ID, got)
			}
		}
	}
}

func TestGetZettelJSON(t *testing.T) {
	t.Parallel()
	c := getClient()
	c.SetAuth("owner", "owner")
	z, err := c.GetZettelJSON(context.Background(), id.DefaultHomeZid)
	if err != nil {
		t.Error(err)
		return
	}
	if m := z.Meta; len(m) == 0 {
		t.Errorf("Exptected non-empty meta, but got %v", z.Meta)
	}
	if z.Content == "" || z.Encoding != "" {
		t.Errorf("Expect non-empty content, but empty encoding (got %q)", z.Encoding)
	}
}

func TestGetParsedEvaluatedZettel(t *testing.T) {
	t.Parallel()
	c := getClient()
	c.SetAuth("owner", "owner")
	encodings := []api.EncodingEnum{
		api.EncoderDJSON,
		api.EncoderHTML,
		api.EncoderNative,
		api.EncoderText,
	}
	for _, enc := range encodings {
		content, err := c.GetParsedZettel(context.Background(), id.DefaultHomeZid, enc)
		if err != nil {
			t.Error(err)
			continue
		}
		if len(content) == 0 {
			t.Errorf("Empty content for parsed encoding %v", enc)
		}
		content, err = c.GetEvaluatedZettel(context.Background(), id.DefaultHomeZid, enc)
		if err != nil {
			t.Error(err)
			continue
		}
		if len(content) == 0 {
			t.Errorf("Empty content for evaluated encoding %v", enc)
		}
	}
}

func checkZid(t *testing.T, expected id.Zid, got string) bool {
	t.Helper()
	if exp := expected.String(); exp != got {
		t.Errorf("Expected a Zid %q, but got %q", exp, got)
		return false
	}
	return true
}

func checkListZid(t *testing.T, l []api.ZidMetaJSON, pos int, expected id.Zid) {
	t.Helper()
	exp := expected.String()
	if got := l[pos].ID; got != exp {
		t.Errorf("Expected result[%d]=%v, but got %v", pos, exp, got)
	}
}

func TestGetZettelOrder(t *testing.T) {
	t.Parallel()
	c := getClient()
	c.SetAuth("owner", "owner")
	rl, err := c.GetZettelOrder(context.Background(), id.TOCNewTemplateZid)
	if err != nil {
		t.Error(err)
		return
	}
	if !checkZid(t, id.TOCNewTemplateZid, rl.ID) {
		return
	}
	l := rl.List
	if got := len(l); got != 2 {
		t.Errorf("Expected list fo length 2, got %d", got)
		return
	}
	checkListZid(t, l, 0, id.TemplateNewZettelZid)
	checkListZid(t, l, 1, id.TemplateNewUserZid)
}

func TestGetZettelContext(t *testing.T) {
	t.Parallel()
	c := getClient()
	c.SetAuth("owner", "owner")
	rl, err := c.GetZettelContext(context.Background(), id.VersionZid, client.DirBoth, 0, 3)
	if err != nil {
		t.Error(err)
		return
	}
	if !checkZid(t, id.VersionZid, rl.ID) {
		return
	}
	l := rl.List
	if got := len(l); got != 3 {
		t.Errorf("Expected list fo length 3, got %d", got)
		return
	}
	checkListZid(t, l, 0, id.DefaultHomeZid)
	checkListZid(t, l, 1, id.OperatingSystemZid)
	checkListZid(t, l, 2, id.StartupConfigurationZid)

	rl, err = c.GetZettelContext(context.Background(), id.VersionZid, client.DirBackward, 0, 0)
	if err != nil {
		t.Error(err)
		return
	}
	if !checkZid(t, id.VersionZid, rl.ID) {
		return
	}
	l = rl.List
	if got := len(l); got != 1 {
		t.Errorf("Expected list fo length 1, got %d", got)
		return
	}
	checkListZid(t, l, 0, id.DefaultHomeZid)
}

func TestGetZettelLinks(t *testing.T) {
	t.Parallel()
	c := getClient()
	c.SetAuth("owner", "owner")
	zl, err := c.GetZettelLinks(context.Background(), id.DefaultHomeZid)
	if err != nil {
		t.Error(err)
		return
	}
	if !checkZid(t, id.DefaultHomeZid, zl.ID) {
		return
	}
	if len(zl.Linked.Incoming) != 0 {
		t.Error("No incomings expected", zl.Linked.Incoming)
	}
	if got := len(zl.Linked.Outgoing); got != 4 {
		t.Errorf("Expected 4 outgoing links, got %d", got)
	}
	if got := len(zl.Linked.Local); got != 1 {
		t.Errorf("Expected 1 local link, got %d", got)
	}
	if got := len(zl.Linked.External); got != 4 {
		t.Errorf("Expected 4 external link, got %d", got)
	}
}

func TestListTags(t *testing.T) {
	t.Parallel()
	c := getClient()
	c.SetAuth("owner", "owner")
	tm, err := c.ListTags(context.Background())
	if err != nil {
		t.Error(err)
		return
	}
	tags := []struct {
		key  string
		size int
	}{
		{"#invisible", 1},
		{"#user", 4},
		{"#test", 4},
	}
	if len(tm) != len(tags) {
		t.Errorf("Expected %d different tags, but got only %d (%v)", len(tags), len(tm), tm)
	}
	for _, tag := range tags {
		if zl, ok := tm[tag.key]; !ok {
			t.Errorf("No tag %v: %v", tag.key, tm)
		} else if len(zl) != tag.size {
			t.Errorf("Expected %d zettel with tag %v, but got %v", tag.size, tag.key, zl)
		}
	}
	for i, id := range tm["#user"] {
		if id != tm["#test"][i] {
			t.Errorf("Tags #user and #test have different content: %v vs %v", tm["#user"], tm["#test"])
		}
	}
}

func TestListRoles(t *testing.T) {
	t.Parallel()
	c := getClient()
	c.SetAuth("owner", "owner")
	rl, err := c.ListRoles(context.Background())
	if err != nil {
		t.Error(err)
		return
	}
	exp := []string{"configuration", "user", "zettel"}
	if len(rl) != len(exp) {
		t.Errorf("Expected %d different tags, but got only %d (%v)", len(exp), len(rl), rl)
	}
	for i, id := range exp {
		if id != rl[i] {
			t.Errorf("Role list pos %d: expected %q, got %q", i, id, rl[i])
		}
	}
}

var baseURL string

func init() {
	flag.StringVar(&baseURL, "base-url", "", "Base URL")
}

func getClient() *client.Client { return client.NewClient(baseURL) }

// TestMain controls whether client API tests should run or not.
func TestMain(m *testing.M) {
	flag.Parse()
	if baseURL != "" {
		m.Run()
	}
}

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

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

// ---------- Subcommand: file -----------------------------------------------

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

	return 0, nil
}

func getInput(args []string) (*meta.Meta, *input.Input, error) {
	if len(args) < 1 {
		src, err := io.ReadAll(os.Stdin)
		if err != nil {
			return nil, nil, err
		}
		inp := input.NewInput(string(src))
		inp := input.NewInput(src)
		m := meta.NewFromInput(id.New(true), inp)
		return m, inp, nil
	}

	src, err := os.ReadFile(args[0])
	if err != nil {
		return nil, nil, err
	}
	inp := input.NewInput(string(src))
	inp := input.NewInput(src)
	m := meta.NewFromInput(id.New(true), inp)

	if len(args) > 1 {
		src, err := os.ReadFile(args[1])
		src, err = os.ReadFile(args[1])
		if err != nil {
			return nil, nil, err
		}
		inp = input.NewInput(string(src))
		inp = input.NewInput(src)
	}
	return m, inp, nil
}

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

package cmd

import (
	"flag"
	"fmt"
	"os"

	"golang.org/x/term"

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

// ---------- Subcommand: password -------------------------------------------

func cmdPassword(fs *flag.FlagSet, cfg *meta.Meta) (int, error) {
func cmdPassword(fs *flag.FlagSet) (int, error) {
	if fs.NArg() == 0 {
		fmt.Fprintln(os.Stderr, "User name and user zettel identification missing")
		return 2, nil
	}
	if fs.NArg() == 1 {
		fmt.Fprintln(os.Stderr, "User zettel identification missing")
		return 2, nil

	ident := fs.Arg(0)
	hashedPassword, err := cred.HashCredential(zid, ident, password)
	if err != nil {
		return 2, err
	}
	fmt.Printf("%v: %s\n%v: %s\n",
		meta.KeyCredential, hashedPassword,
		meta.KeyUserID, ident,
		api.KeyCredential, hashedPassword,
		api.KeyUserID, ident,
	)
	return 0, nil
}

func getPassword(prompt string) (string, error) {
	fmt.Fprintf(os.Stderr, "%s: ", prompt)
	password, err := term.ReadPassword(int(os.Stdin.Fd()))
	fmt.Fprintln(os.Stderr)
	return string(password), err
}

import (
	"flag"

	"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"
)

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

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

func withDebug(fs *flag.FlagSet) bool {
func runFunc(*flag.FlagSet) (int, error) {
	dbg := fs.Lookup("debug")
	return dbg != nil && dbg.Value.String() == "true"
}

func runFunc(fs *flag.FlagSet, _ *meta.Meta) (int, error) {
	exitCode, err := doRun(withDebug(fs))
	exitCode, err := doRun()
	kernel.Main.WaitForShutdown()
	return exitCode, err
}

func doRun(debug bool) (int, error) {
func doRun() (int, error) {
	kern := kernel.Main
	kern.SetDebug(debug)
	if err := kern.StartService(kernel.WebService); err != nil {
	if err := kernel.Main.StartService(kernel.WebService); err != nil {
		return 1, err
	}
	return 0, nil
}

func setupRouting(webSrv server.Server, boxManager box.Manager, authManager auth.Manager, rtConfig config.Config) {
	protectedBoxManager, authPolicy := authManager.BoxWithPolicy(webSrv, boxManager, rtConfig)
	a := api.New(webSrv, authManager, authManager, webSrv, rtConfig)
	wui := webui.New(webSrv, authManager, rtConfig, authManager, boxManager, authPolicy)

	ucAuthenticate := usecase.NewAuthenticate(authManager, authManager, boxManager)
	ucCreateZettel := usecase.NewCreateZettel(rtConfig, protectedBoxManager)
	ucGetMeta := usecase.NewGetMeta(protectedBoxManager)
	ucGetAllMeta := usecase.NewGetAllMeta(protectedBoxManager)
	ucGetZettel := usecase.NewGetZettel(protectedBoxManager)
	ucParseZettel := usecase.NewParseZettel(rtConfig, ucGetZettel)
	ucEvaluate := usecase.NewEvaluate(rtConfig, ucGetZettel, ucGetMeta)
	ucListMeta := usecase.NewListMeta(protectedBoxManager)
	ucListRoles := usecase.NewListRole(protectedBoxManager)
	ucListTags := usecase.NewListTags(protectedBoxManager)
	ucZettelContext := usecase.NewZettelContext(protectedBoxManager)
	ucZettelContext := usecase.NewZettelContext(protectedBoxManager, rtConfig)
	ucDelete := usecase.NewDeleteZettel(protectedBoxManager)
	ucUpdate := usecase.NewUpdateZettel(protectedBoxManager)
	ucRename := usecase.NewRenameZettel(protectedBoxManager)

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

	// Web user interface
	if !authManager.IsReadonly() {
		webSrv.AddZettelRoute('b', server.MethodGet, wui.MakeGetRenameZettelHandler(ucGetMeta))
		webSrv.AddZettelRoute('b', server.MethodGet, wui.MakeGetRenameZettelHandler(
			ucGetMeta, &ucEvaluate))
		webSrv.AddZettelRoute('b', server.MethodPost, wui.MakePostRenameZettelHandler(ucRename))
		webSrv.AddZettelRoute('c', server.MethodGet, wui.MakeGetCopyZettelHandler(
			ucGetZettel, usecase.NewCopyZettel()))
		webSrv.AddZettelRoute('c', server.MethodPost, wui.MakePostCreateZettelHandler(ucCreateZettel))
		webSrv.AddZettelRoute('d', server.MethodGet, wui.MakeGetDeleteZettelHandler(ucGetZettel))
		webSrv.AddZettelRoute('d', server.MethodGet, wui.MakeGetDeleteZettelHandler(
			ucGetMeta, ucGetAllMeta, &ucEvaluate))
		webSrv.AddZettelRoute('d', server.MethodPost, wui.MakePostDeleteZettelHandler(ucDelete))
		webSrv.AddZettelRoute('e', server.MethodGet, wui.MakeEditGetZettelHandler(ucGetZettel))
		webSrv.AddZettelRoute('e', server.MethodPost, wui.MakeEditSetZettelHandler(ucUpdate))
		webSrv.AddZettelRoute('f', server.MethodGet, wui.MakeGetFolgeZettelHandler(
			ucGetZettel, usecase.NewFolgeZettel(rtConfig)))
		webSrv.AddZettelRoute('f', server.MethodPost, wui.MakePostCreateZettelHandler(ucCreateZettel))
		webSrv.AddZettelRoute('g', server.MethodGet, wui.MakeGetNewZettelHandler(

	// API
	webSrv.AddListRoute('a', server.MethodPost, a.MakePostLoginHandler(ucAuthenticate))
	webSrv.AddListRoute('a', server.MethodPut, a.MakeRenewAuthHandler())
	webSrv.AddListRoute('j', server.MethodGet, api.MakeListMetaHandler(ucListMeta))
	webSrv.AddZettelRoute('j', server.MethodGet, api.MakeGetZettelHandler(ucGetZettel))
	webSrv.AddZettelRoute('l', server.MethodGet, api.MakeGetLinksHandler(ucEvaluate))
	webSrv.AddZettelRoute('m', server.MethodGet, api.MakeGetMetaHandler(ucGetMeta))
	webSrv.AddZettelRoute('o', server.MethodGet, api.MakeGetOrderHandler(
		usecase.NewZettelOrder(protectedBoxManager, ucEvaluate)))
	webSrv.AddZettelRoute('p', server.MethodGet, a.MakeGetParsedZettelHandler(ucParseZettel))
	webSrv.AddListRoute('r', server.MethodGet, api.MakeListRoleHandler(ucListRoles))
	webSrv.AddListRoute('t', server.MethodGet, api.MakeListTagsHandler(ucListTags))
	webSrv.AddListRoute('v', server.MethodPost, a.MakePostEncodeInlinesHandler(ucEvaluate))
	webSrv.AddZettelRoute('v', server.MethodGet, a.MakeGetEvalZettelHandler(ucEvaluate))
	webSrv.AddZettelRoute('x', server.MethodGet, api.MakeZettelContextHandler(ucZettelContext))
	webSrv.AddListRoute('z', server.MethodGet, a.MakeListPlainHandler(ucListMeta))
	webSrv.AddZettelRoute('z', server.MethodGet, a.MakeGetPlainZettelHandler(ucGetZettel))
	if !authManager.IsReadonly() {
		webSrv.AddListRoute('j', server.MethodPost, a.MakePostCreateZettelHandler(ucCreateZettel))
		webSrv.AddZettelRoute('j', server.MethodPut, api.MakeUpdateZettelHandler(ucUpdate))

import (
	"flag"
	"fmt"
	"os"
	"strings"

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

func flgSimpleRun(fs *flag.FlagSet) {
	fs.String("d", "", "zettel directory")
}

func runSimpleFunc(fs *flag.FlagSet, cfg *meta.Meta) (int, error) {
func runSimpleFunc(*flag.FlagSet) (int, error) {
	kern := kernel.Main
	listenAddr := kern.GetConfig(kernel.WebService, kernel.WebListenAddress).(string)
	exitCode, err := doRun(false)
	exitCode, err := doRun()
	if idx := strings.LastIndexByte(listenAddr, ':'); idx >= 0 {
		kern.Log()
		kern.Log("--------------------------")
		kern.Log("Open your browser and enter the following URL:")
		kern.Log()
		kern.Log(fmt.Sprintf("    http://localhost%v", listenAddr[idx:]))
		kern.Log()

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

package cmd

import (
	"flag"
	"sort"

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

// Command stores information about commands / sub-commands.
type Command struct {
	Name       string              // command name as it appears on the command line
	Func       CommandFunc         // function that executes a command
	Boxes      bool                // if true then boxes will be set up
	Header     bool                // Print a heading on startup
	LineServer bool                // Start admin line server
	Flags      func(*flag.FlagSet) // function to set up flag.FlagSet
	flags      *flag.FlagSet       // flags that belong to the command

}

// CommandFunc is the function that executes the command.
// It accepts the parsed command line parameters.
// It returns the exit code and an error.
type CommandFunc func(*flag.FlagSet, *meta.Meta) (int, error)
type CommandFunc func(*flag.FlagSet) (int, error)

// GetFlags return the flag.FlagSet defined for the command.
func (c *Command) GetFlags() *flag.FlagSet { return c.flags }

var commands = make(map[string]Command)

// RegisterCommand registers the given command.

	"fmt"
	"net"
	"net/url"
	"os"
	"strconv"
	"strings"

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

const (
	defConfigfile = ".zscfg"
)

func init() {
	RegisterCommand(Command{
		Name: "help",
		Func: func(*flag.FlagSet, *meta.Meta) (int, error) {
		Func: func(*flag.FlagSet) (int, error) {
			fmt.Println("Available commands:")
			for _, name := range List() {
				fmt.Printf("- %q\n", name)
			}
			return 0, nil
		},
	})
	RegisterCommand(Command{
		Name:   "version",
		Func:   func(*flag.FlagSet, *meta.Meta) (int, error) { return 0, nil },
		Func:   func(*flag.FlagSet) (int, error) { return 0, nil },
		Header: true,
	})
	RegisterCommand(Command{
		Name:       "run",
		Func:       runFunc,
		Boxes:      true,
		Header:     true,

	} else {
		configFile = defConfigfile
	}
	content, err := os.ReadFile(configFile)
	if err != nil {
		return meta.New(id.Invalid)
	}
	return meta.NewFromInput(id.Invalid, input.NewInput(string(content)))
	return meta.NewFromInput(id.Invalid, input.NewInput(content))
}

func getConfig(fs *flag.FlagSet) *meta.Meta {
	cfg := readConfig(fs)
	fs.Visit(func(flg *flag.Flag) {
		switch flg.Name {
		case "p":

		case "d":
			val := flg.Value.String()
			if strings.HasPrefix(val, "/") {
				val = "dir://" + val
			} else {
				val = "dir:" + val
			}
			deleteConfiguredBoxes(cfg)
			cfg.Set(keyBoxOneURI, val)
		case "debug":
			cfg.Set(keyDebug, flg.Value.String())
		case "r":
			cfg.Set(keyReadOnly, flg.Value.String())
		case "v":
			cfg.Set(keyVerbose, flg.Value.String())
		}
	})
	return cfg
}

func parsePort(s string) (string, error) {
	port, err := net.LookupPort("tcp", s)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Wrong port specification: %q", s)
		return "", err
	}
	return strconv.Itoa(port), nil
}

func deleteConfiguredBoxes(cfg *meta.Meta) {
	for _, p := range cfg.PairsRest(false) {
		if key := p.Key; strings.HasPrefix(key, kernel.BoxURIs) {
			cfg.Delete(key)
		}
	}
}

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

func setServiceConfig(cfg *meta.Meta) error {
	ok := setConfigValue(true, kernel.CoreService, kernel.CoreVerbose, cfg.GetBool(keyVerbose))
	ok := setConfigValue(true, kernel.CoreService, kernel.CoreDebug, cfg.GetBool(keyDebug))
	ok = setConfigValue(ok, kernel.CoreService, kernel.CoreVerbose, cfg.GetBool(keyVerbose))
	if val, found := cfg.Get(keyAdminPort); found {
		ok = setConfigValue(ok, kernel.CoreService, kernel.CorePort, val)
	}

	ok = setConfigValue(ok, kernel.AuthService, kernel.AuthOwner, cfg.GetDefault(keyOwner, ""))
	ok = setConfigValue(ok, kernel.AuthService, kernel.AuthReadonly, cfg.GetBool(keyReadOnly))

	cfg := getConfig(fs)
	if err := setServiceConfig(cfg); err != nil {
		fmt.Fprintf(os.Stderr, "%s: %v\n", name, err)
		return 2
	}
	setupOperations(cfg, command.Boxes)
	kernel.Main.Start(command.Header, command.LineServer)
	exitCode, err := command.Func(fs, cfg)
	exitCode, err := command.Func(fs)
	if err != nil {
		fmt.Fprintf(os.Stderr, "%s: %v\n", name, err)
	}
	kernel.Main.Shutdown(true)
	return exitCode
}

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

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

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

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

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

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

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

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

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

id: 20210916193200
title: Required Software
role: zettel
syntax: zmk
modified: 20210916194748
modified: 20211111143928

The following software must be installed:

* A current, supported [[release of Go|https://golang.org/doc/devel/release.html]],
* [[golint|https://github.com/golang/lint]],
* [[shadow|https://pkg.go.dev/golang.org/x/tools/go/analysis/passes/shadow]] via ``go install golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow@latest``,
* [[staticcheck|https://staticcheck.io/]] via ``go get honnef.co/go/tools/cmd/staticcheck``,
* [[unparam|mvdan.cc/unparam]][^[[GitHub|https://github.com/mvdan/unparam]]] via ``go install mvdan.cc/unparam@latest``
* [[unparam|https://mvdan.cc/unparam]][^[[GitHub|https://github.com/mvdan/unparam]]] via ``go install mvdan.cc/unparam@latest``

Make sure that the software is in your path, e.g. via:

```sh
export PATH=$PATH:/usr/local/go/bin
export PATH=$PATH:$(go env GOPATH)/bin
```

id: 20210916194900
title: Checklist for Release
role: zettel
syntax: zmk
modified: 20210917165448
modified: 20211110193448

# Check for unused parameters:
#* ``unparam ./...``
#* ``unparam -exported -tests ./...``
# Clean up your Go workspace:
#* ``go run tools/build.go clean`` (alternatively: ``make clean``).
# All internal tests must succeed:
#* ``go run tools/build.go check`` (alternatively: ``make check``).
#* ``go run tools/build.go relcheck`` (alternatively: ``make relcheck``).
# The API tests must succeed on every development platform:
#* ``go run tools/build.go testapi`` (alternatively: ``make api``).
# Run [[linkchecker|https://linkchecker.github.io/linkchecker/]] with the manual:
#* ``go run -race cmd/zettelstore/main.go run -d docs/manual``
#* ``linkchecker  http://127.0.0.1:23123 2>&1 | tee lc.txt``
#* Check all ""Error: 404 Not Found""
#* Check all ""Error: 403 Forbidden"": allowed for endpoint ''/p'' with encoding ''html'' for those zettel that are accessible only in ''expert-mode''.

#* download.wiki
#* changes.wiki
#* plan.wiki
# Set file ''VERSION'' to the new release version
# Disable Fossil autosync mode:
#* ``fossil setting autosync off``
# Commit the new release version:
#* ``fossil commit --tag release --tag version-VERSION -m "Version VERSION"``
#* ``fossil commit --tag release --tag vVERSION -m "Version VERSION"``
#* **Important:** the tag must follow the given pattern, e.g. ''v0.0.15''.
   Otherwise client will not be able to import ''zettelkasten.de/z''.
# Clean up your Go workspace:
#* ``go run tools/build.go clean`` (alternatively: ``make clean``).
# Create the release:
#* ``go run tools/build.go release`` (alternatively: ``make release``).
# Remove previous executables:
#* ``fossil uv remove --glob '*-PREVVERSION*'``
# Add executables for release:

id: 00001000000000
title: Zettelstore Manual
role: manual
tags: #manual #zettelstore
syntax: zmk
modified: 20211027121716

* [[Introduction|00001001000000]]
* [[Design goals|00001002000000]]
* [[Installation|00001003000000]]
* [[Configuration|00001004000000]]
* [[Structure of Zettelstore|00001005000000]]
* [[Layout of a zettel|00001006000000]]
* [[Zettelmarkup|00001007000000]]
* [[Other markup languages|00001008000000]]
* [[Security|00001010000000]]
* [[API|00001012000000]]
* [[Web user interface|00001014000000]]
* Troubleshooting
* [[Troubleshooting|00001018000000]]
* Frequently asked questions

Licensed under the EUPL-1.2-or-later.

id: 00001004010000
title: Zettelstore startup configuration
role: manual
tags: #configuration #manual #zettelstore
syntax: zmk
modified: 20210712234656
modified: 20211109172143

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''
; [!box-uri-x]''box-uri-//X//'', where //X// is a number greater or equal to one
; [!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.
  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.
; [!debug-mode]''debug-mode''
: Allows to debug the Zettelstore software (mostly used by the developers).
  Disables any timeout values of the internal web server and does not send some security-related data.

  Do not enable it for a production server.

  Default: ''false''
; [!default-dir-box-type]''default-dir-box-type''
: Specifies the default value for the (sub-) type of [[directory boxes|00001004011400#type]].
  Zettel are typically stored in such boxes.

  Default: ''notify''
; [!insecure-cookie]''insecure-cookie''
: Must be set to ''true'', if authentication is enabled and Zettelstore is not accessible not via HTTPS (but via HTTP).

  It is automatically extended, when a new HTML view is rendered.
; [!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'').
  Default: ''"/"''.

  This allows to use a forwarding proxy [[server|00001010090100]] in front of the Zettelstore.
; ''verbose''
: Be more verbose inf logging data.
; [!verbose-mode]''verbose-mode''
: Be more verbose when logging data.
  Default: false

id: 00001004011200
title: Zettelstore boxes
role: manual
tags: #configuration #manual #zettelstore
syntax: zmk
modified: 20210525121452
modified: 20211103163225

A Zettelstore must store its zettel somehow and somewhere.
In most cases you want to store your zettel as files in a directory.
Under certain circumstances you may want to store your zettel elsewhere.

An example are the [[predefined zettel|00001005090000]] that come with a Zettelstore.
They are stored within the software itself.
In another situation you may want to store your zettel volatile, e.g. if you want to provide a sandbox for experimenting.

To cope with these (and more) situations, you configure Zettelstore to use one or more //boxes//{-}.
To cope with these (and more) situations, you configure Zettelstore to use one or more __boxes__.
This is done via the ''box-uri-X'' keys of the [[startup configuration|00001004010000#box-uri-X]] (X is a number).
Boxes are specified using special [[URIs|https://en.wikipedia.org/wiki/Uniform_Resource_Identifier]], somehow similar to web addresses.

The following box URIs are supported:

; ''dir:\//DIR''
; [!dir]''dir:\//DIR''
: Specifies a directory where zettel files are stored.
  ''DIR'' is the file path.
  Although it is possible to use relative file paths, such as ''./zettel'' (→ URI is ''dir:\//.zettel''), it is preferable to use absolute file paths, e.g. ''/home/user/zettel''.

  The directory must exist before starting the Zettelstore[^There is one exception: when Zettelstore is [[started without any parameter|00001004050000]], e.g. via double-clicking its icon, an directory called ''./zettel'' will be created.].

  It is possible to [[configure|00001004011400]] a directory box.
; ''file:FILE.zip'' oder ''file:/\//path/to/file.zip''
; [!file]''file:FILE.zip'' oder ''file:/\//path/to/file.zip''
: Specifies a ZIP file which contains files that store zettel.
  You can create such a ZIP file, if you zip a directory full of zettel files.

  This box is always read-only.
; ''mem:''
; [!mem]''mem:''
: Stores all its zettel in volatile memory.
  If you stop the Zettelstore, all changes are lost.

All boxes that you configure via the ''box-uri-X'' keys form a chain of boxes.
If a zettel should be retrieved, a search starts in the box specified with the ''box-uri-2'' key, then ''box-uri-3'' and so on.
If a zettel is created or changed, it is always stored in the box specified with the ''box-uri-1'' key.
This allows to overwrite zettel from other boxes, e.g. the predefined zettel.

id: 00001004051000
title: The ''run'' sub-command
role: manual
tags: #command #configuration #manual #zettelstore
syntax: zmk
modified: 20210712234419
modified: 20211109172046

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

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

  If you want to listen on network card to process requests from other computer, please use [[''listen-addr''|00001004010000#listen-addr]] of the configuration file as described below.
; [!r]''-r''
: Puts the Zettelstore in read-only mode.
  No changes are possible via the web interface / via the API.

  This allows to publish your content without any risks of unauthorized changes.
; [!v]''-v''
: Be more verbose in writing logs.
: Be more verbose when writing logs.

Command line options take precedence over [[configuration file|00001004010000]] options.

id: 00001004100000
title: Zettelstore Administrator Console
role: manual
tags: #configuration #manual #zettelstore
syntax: zmk
modified: 20210510155859
modified: 20211103162926

The administrator console is a service accessible only on the same computer on which Zettelstore is running.
It allows an experienced user to monitor and control some of the inner workings of Zettelstore.

You enable the administrator console by specifying a TCP port number greater than zero (better: greater than 1024) for it, either via the [[command-line parameter ''-a''|00001004051000#a]] or via the ''admin-port'' key of the [[startup configuration file|00001004010000#admin-port]].

After you enable the administrator console, you can use tools such as [[PuTTY|https://www.chiark.greenend.org.uk/~sgtatham/putty/]] or other telnet software to connect to the administrator console.
In fact, the administrator console is //not// a full telnet service.
In fact, the administrator console is __not__ a full telnet service.
It is merely a simple line-oriented service where each input line is interpreted separately.
Therefore, you can also use tools like [[netcat|https://nc110.sourceforge.io/]], [[socat|http://www.dest-unreach.org/socat/]], etc.

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

id: 00001004101000
title: List of supported commands of the administrator console
role: manual
tags: #configuration #manual #zettelstore
syntax: zmk
modified: 20210525161623
modified: 20211103161956

; ''bye''
: Closes the connection to the administrator console.
; ''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.

: Displays s list of all available services and their current status.
; ''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.

  If the key specifies a list value, all other list values with a number greater than the given key are deleted.
  You can use the special number ""0"" to delete all values.
  E.g. ``set-config box box-uri-0 any_text`` will remove all values of the list //box-uri-//.
  E.g. ``set-config box box-uri-0 any_text`` will remove all values of the list __box-uri-__.
; ''shutdown''
: Terminate the Zettelstore itself (and closes the connection to the administrator console).
; ''start SERVICE''
: Start the given bservice and all dependent services.
; ''stat SERVICE''
: Display some statistical values for the given service.
; ''stop SERVICE''
: Stop the given service and all other that depend on this.

id: 00001005000000
title: Structure of Zettelstore
role: manual
tags: #design #manual #zettelstore
syntax: zmk
modified: 20210614165848
modified: 20211103163918

Zettelstore is a software that manages your zettel.
Since every zettel must be readable without any special tool, most zettel has to be stored as ordinary files within specific directories.
Typically, file names and file content must comply to specific rules so that Zettelstore can manage them.
If you add, delete, or change zettel files with other tools, e.g. a text editor, Zettelstore will monitor these actions.

Zettelstore provides additional services to the user.

Every file in this directory that should be monitored by Zettelstore must have a file name that begins with 14 digits (0-9), the [[zettel identifier|00001006050000]].
If you create a new zettel via the web interface or the API, the zettel identifier will be the timestamp of the current date and time (format is ''YYYYMMDDhhmmss'').
This allows zettel to be sorted naturally by creation time.

Since the only restriction on zettel identifiers are the 14 digits, you are free to use other digit sequences.
The [[configuration zettel|00001004020000]] is one prominent example, as well as these manual zettel.
You can create these special zettel identifiers either with the //rename// function of Zettelstore or by manually renaming the underlying zettel files.
You can create these special zettel identifiers either with the __rename__ function of Zettelstore or by manually renaming the underlying zettel files.

It is allowed that the file name contains other characters after the 14 digits.
These are ignored by Zettelstore.

The file name must have an file extension.
Two file extensions are used by Zettelstore: ''.meta'' and ''.zettel''.
Other file extensions are used to determine the ""syntax"" of a zettel.

If you want to read the original zettel, you either have to delete the zettel (which removes it from the file directory), or you have to rename it to another zettel identifier.
Now we have two places where zettel are stored: in the specific directory and within the Zettelstore software.

* [[List of predefined zettel|00001005090000]]

=== Boxes: other ways to store zettel
As described above, a zettel may be stored as a file inside a directory or inside the Zettelstore software itself.
Zettelstore allows other ways to store zettel by providing an abstraction called //box//.[^Formerly, zettel were stored physically in boxes, often made of wood.]
Zettelstore allows other ways to store zettel by providing an abstraction called __box__.[^Formerly, zettel were stored physically in boxes, often made of wood.]

A file directory which stores zettel is called a ""directory box"".
But zettel may be also stored in a ZIP file, which is called ""file box"".
For testing purposes, zettel may be stored in volatile memeory (called //RAM//).
For testing purposes, zettel may be stored in volatile memory (called __RAM__).
This way is called ""memory box"".

Other types of boxes could be added to Zettelstore.
What about a ""remote Zettelstore box""?

id: 00001006010000
title: Syntax of Metadata
role: manual
tags: #manual #syntax #zettelstore
syntax: zmk
role: manual
modified: 20211103164152

The metadata of a zettel is a collection of key-value pairs.
The syntax roughly resembles the internal header of an email ([[RFC5322|https://tools.ietf.org/html/rfc5322]]).

The key is a sequence of alphanumeric characters, a hyphen-minus character (""''-''"") is also allowed.
It begins at the first position of a new line.

A key is separated from its value either by
* a colon character (""'':''""),
* a non-empty sequence of space characters,
* a sequence of space characters, followed by a colon, followed by a sequence of space characters.

A Value is a sequence of printable characters.
If the value should be continued in the following line, that following line (//continuation line//) must begin with a non-empty sequence of space characters.
If the value should be continued in the following line, that following line (""continuation line"") must begin with a non-empty sequence of space characters.
The rest of the following line will be interpreted as the next part of the value.
There can be more than one continuation line for a value.

A non-continuation line that contains a possibly empty sequence of characters, followed by the percent sign character (""''%''"") is treated as a comment line.
It will be ignored.

Parsing metadata ends, if an empty line is found or if a line with at least three hyphen-minus characters is found.

id: 00001006020000
title: Supported Metadata Keys
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
modified: 20210822234119
modified: 20211103163613

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

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

; [!all-tags]''all-tags''
: A property (a computed values that is not stored) that contains both the value of [[''tags''|#tags]] together with all [[tags|00001007040000#tag]] that are specified within the content.
; [!back]''back''
: Is a property that contains the identifier of all zettel that reference the zettel of this metadata, that are not referenced by this zettel.
  Basically, it is the value of [[''backward''|#bachward]], but without any zettel identifier that is contained in [[''forward''|#forward]].
; [!backward]''backward''
: Is a property that contains the identifier of all zettel that reference the zettel of this metadata.
  References within inversable values are not included here, e.g. [[''precursor''|#precursor]].
  References within invertible values are not included here, e.g. [[''precursor''|#precursor]].
; [!box-number]''box-number''
: Is a computed value and contains the number of the box where the zettel was found.
  For all but the [[predefined zettel|00001005090000]], this number is equal to the number __X__ specified in startup configuration key [[''box-uri-__X__''|00001004010000#box-uri-x]].
; [!copyright]''copyright''
: 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.
; [!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.
: Property that contains all references that does __not__ identify a zettel.
; [!duplicates]''duplicates''
: Is set to the value ""true"" if there is more than one file that could contain the content of a zettel.
  Is used for [[directory boxes|00001004011400]] and [[file boxes|00001004011200#file]].
; [!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.

; [!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.
; [!no-index]''no-index''
: If set to true, the zettel will not be indexed and therefore not be found in full-text searches.
: If set to a ""true"" value, the zettel will not be indexed and therefore not be found in full-text searches.
; [!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]].
; [!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.
  Otherwise, if the zettel identifier contains a valid timestamp, the identifier is used.

id: 00001006055000
title: Reserved zettel identifier
role: manual
tags: #design #manual #zettelstore
syntax: zmk
modified: 20210917154229
modified: 20211001125243

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

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

| 00000200000000 | 0000899999999 | Reserved for future use
| 00009000000000 | 0000999999999 | Reserved for applications

This list may change in the future.

==== External Applications
|= From | To | Description
| 00009000001000 | 00009000001999 | ZS Slides, an application to display zettel as a HTML-based slideshow
| 00009000001000 | 00009000001999 | [[Zettel Presenter|https://zettelstore.de/contrib]], an application to display zettel as a HTML-based slideshow

id: 00001007000000
title: Zettelmarkup
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
role: manual
modified: 20211103162744

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

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

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

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

Zettelmarkup might be seen as a proprietary markup language.
But if you want to use Markdown/CommonMark and you need support for footnotes, you'll end up with a proprietary extension.
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]]
* [[Summary of formatting characters|00001007060000]]

id: 00001007030100
title: Zettelmarkup: Description Lists
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
role: manual
modified: 20211103163447

A description list is a sequence of terms to be described together with the descriptions of each term.
Every term can described in multiple ways.

A description term (short: //term//) is specified with one semicolon (""'';''"", ''U+003B'') at the first position, followed by a space character and the described term, specified as a sequence of line elements.
A description term (short: __term__) is specified with one semicolon (""'';''"", ''U+003B'') at the first position, followed by a space character and the described term, specified as a sequence of line elements.
If the following lines should also be part of the term, exactly two spaces must be given at the beginning of each following line.

The description of a term is given with one colon (""'':''"", ''U+003A'') at the first position, followed by a space character and the description itself, specified as a sequence of inline elements.
Similar to terms, following lines can also be part of the actual description, if they begin at each line with exactly two space characters.

In contrast to terms, the actual descriptions are merged into a paragraph.
This is because, an actual description can contain more than one paragraph.

id: 00001007030200
title: Zettelmarkup: Nested Lists
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
role: manual
modified: 20211103162835

There are thee kinds of lists that can be nested: ordered lists, unordered lists, and quotation lists.

Ordered lists are specified with the number sign (""''#''"", ''U+0023''), unordered lists use the asterisk (""''*''"", ''U+002A''), and quotation lists are specified with the greater-than sing (""''>''"", ''U+003E'').
Let's call these three characters //list characters//.
Let's call these three characters __list characters__.

Any nested list item is specified by a non-empty sequence of list characters, followed by a space character and a sequence of inline elements.
In case of a quotation list as the last list character, the space character followed by a sequence of inline elements is optional.
The number / count of list characters gives the nesting of the lists.
If the following lines should also be part of the list item, exactly the same number of spaces must be given at the beginning of each of the following lines as it is the lists are nested, plus one additional space character.
In other words: the inline elements must begin at the same column as it was on the previous line.

id: 00001007030300
title: Zettelmarkup: Headings
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
role: manual
modified: 20211103163105

To specify a (sub-) section of a zettel, you should use the headings syntax: at
the beginning of a new line type at least three equal signs (""''=''"", ''U+003D''), plus at least one
space and enter the text of the heading as inline elements.

```zmk
=== Level 1 Heading

=== Notes

The heading level is translated to a HTML heading by adding 1 to the level, e.g. ``=== Level 1 Heading``{=zmk} translates to ==<h2>Level 1 Heading</h2>=={=html}.
The ==<h1>=={=html} tag is rendered for the zettel title.

This syntax is often used in a similar way in wiki implementation.
However, trailing equal signs are //not//{-} removed, they are part of the heading text.
However, trailing equal signs are __not__ removed, they are part of the heading text.

If you use command line tools, you can easily create a draft table of contents with the command:

```sh
grep -h '^====* ' ZETTEL_ID.zettel
```

id: 00001007031000
title: Zettelmarkup: Tables
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20210523185812
modified: 20211103161859

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

The first cell of a row must begin with the vertical bar character (""''|''"", ''U+007C'') at the first position of a line.
The other cells of a row begin with the same vertical bar character at later positions in that line.
A cell is delimited by the vertical bar character of the next cell or by the end of the current line.
A vertical bar character as the last character of a line will not result in a table cell.
It will be ignored.

:::example
| a1 | a2 | a3|
| b1 | b2 | b3
| c1 | c2
:::

=== Header row
If any cell in the first row of a table contains an equal sing character (""''=''"", ''U+003D'') as the very first character, then this first row will be interpreted as a //table header// row.
If any cell in the first row of a table contains an equal sing character (""''=''"", ''U+003D'') as the very first character, then this first row will be interpreted as a __table header__ row.

For example:
```zmk
| a1 | a2 |= a3|
| b1 | b2 | b3
| c1 | c2
```

id: 00001007040000
title: Zettelmarkup: Inline-Structured Elements
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20210822234205
modified: 20211103162150

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

==== Comments
A comment begins with two consecutive percent sign characters (""''%''"", ''U+0025'').
It ends at the end of the line where it begins.

==== Backslash
The backslash character (""''\\''"", ''U+005C'') gives the next character another meaning.
* If a space character follows, it is converted in a non-breaking space (''U+00A0'').
* If a line ending follows the backslash character, the line break is converted from a //soft break// into a //hard break//.
* If a line ending follows the backslash character, the line break is converted from a __soft break__ into a __hard break__.
* 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, 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//.
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.

==== 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}.

If you want to enter its numeric code point, a number sign character must follow the ampersand character, followed by digits to base 10.
Example: ``&`` is rendered in HTML as ::&::{=example}.

You also can enter its numeric code point as a hex number, if you put the letter ""x"" after the numeric sign character.
Example: ``&`` is rendered in HTML as ::&::{=example}.

Since some Unicode character are used quite often, a special notation is introduced for them:

* Two consecutive hyphen-minus characters result in an //en-dash// character.
* Two consecutive hyphen-minus characters result in an __en-dash__ character.
  It is typically used in numeric ranges.
  ``pages 4--7`` will be rendered in HTML as: ::pages 4--7::{=example}.
  Alternative specifications are: ``–``, ``&x8211``, and ``&#x2013``.
* Three consecutive full stop characters (""''.''"", ''U+002E'') after a space result in an horizontal ellipsis character.
  ``to be continued ... later`` will be rendered in HTML as: ::to be continued, ... later::{=example}.
  Alternative specifications are: ``…``, ``&x8230``, and ``&#x2026``.

id: 00001007040100
title: Zettelmarkup: Text Formatting
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
role: manual
modified: 20211113175248

Text formatting is the way to make your text visually different.
Every text formatting element begins with two same characters.
It ends when these two same characters occur the second time.
It is possible that some [[attributes|00001007050000]] follow immediately, without any separating character.

Text formatting can be nested, up to a reasonable limit.

The following characters begin a text formatting:

* The low line character (""''_''"", ''U+005F'') emphasizes its text.
** Example: ``abc __def__ ghi`` is rendered in HTML as: ::abc __def__ ghi::{=example}.
* The slash character (""''/''"", ''U+002F'') emphasizes its text. Often, such text is rendered in italics. If the default attribute is specified, the emphasized text is not just rendered as such, but also internally marked as emphasized.
** Example: ``abc //def// ghi`` is rendered in HTML as: ::abc //def// ghi::{=example}.
** The slash character (""''/''"", ''U+002F'') is still allowed to emphasize text, but its use is deprecated.
   With [[version 0.2.0|https://zettelstore.de/home/doc/trunk/www/changes.wiki#0_2_0]] it will no longer be supported. 
*** Example: ``abc //def// ghi`` is rendered in HTML as: ::abc //def// ghi::{=example}.
** Example: ``abc //def//{-} ghi`` is rendered in HTML as: ::abc //def//{-} ghi::{=example}.
* The asterisk character (""''*''"", ''U+002A'') strongly emphasized its enclosed text. The text is often rendered in bold. Again, the default attribute will force a explicit semantic meaning of strong emphasizing.
* The asterisk character (""''*''"", ''U+002A'') strongly emphasized its enclosed text.
** Example: ``abc **def** ghi`` is rendered in HTML as: ::abc **def** ghi::{=example}.
** Example: ``abc **def**{-} ghi`` is rendered in HTML as: ::abc **def**{-} ghi::{=example}.
* The low line character (""''_''"", ''U+005F'') produces underlined text. If the default attribute was specified, it is semantically rendered as inserted text.
** Example: ``abc __def__ ghi`` is rendered in HTML as: ::abc __def__ ghi::{=example}.
* The greater-than sign character (""''>''"", ''U+003E'') marks text as inserted.
** Example: ``abc >>def>> ghi`` is rendered in HTML as: ::abc >>def>> ghi::{=example}.
** Example: ``abc __def__{-} ghi`` is rendered in HTML as: ::abc __def__{-} ghi::{=example}.
* Similar, the tilde character (""''~''"", ''U+007E'') produces text that is strike-through. If the default attribute was specified, it is semantically rendered as deleted text.
* Similar, the tilde character (""''~''"", ''U+007E'') marks deleted text.
** Example: ``abc ~~def~~ ghi`` is rendered in HTML as: ::abc ~~def~~ ghi::{=example}.
** Example: ``abc ~~def~~{-} ghi`` is rendered in HTML as: ::abc ~~def~~{-} ghi::{=example}.
* The apostrophe character (""''\'''"", ''U+0027'') renders text in mono-space / fixed font width.
** Example: ``abc ''def'' ghi`` is rendered in HTML as: ::abc ''def'' ghi::{=example}.
* The circumflex accent character (""''^''"", ''U+005E'') allows to enter superscripted text.
** Example: ``e=mc^^2^^`` is rendered in HTML as: ::e=mc^^2^^::{=example}.
* The comma character (""'',''"", ''U+002C'') produces subscripted text.
** Example: ``H,,2,,O`` is rendered in HTML as: ::H,,2,,O::{=example}.
* The less-than sign character (""''<''"", ''U+003C'') marks an inline quotation.

id: 00001007040322
title: Zettelmarkup: Image Embedding
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20210811165719
modified: 20211103163657

Image content is assumed, if an URL is used or if the referenced zettel contains an image.

Supported formats are:

* Portable Network Graphics (""PNG""), as defined by [[RFC\ 2083|https://tools.ietf.org/html/rfc2083]].
* Graphics Interchange Format (""GIF"), as defined by [[https://www.w3.org/Graphics/GIF/spec-gif89a.txt]].
* JPEG / JPG, defined by the //Joint Photographic Experts Group//.
* JPEG / JPG, defined by the __Joint Photographic Experts Group__.
* Scalable Vector Graphics (SVG), defined by [[https://www.w3.org/Graphics/SVG/]]

If the text is given, it will be interpreted as an alternative textual representation, to help persons with some visual disabilities.

[[Attributes|00001007050000]] are supported.
They must follow the last right curly bracket character immediately.
One prominent example is to specify an explicit title attribute that is shown on certain web browsers when the zettel is rendered in HTML:

id: 00001007040350
title: Zettelmarkup: Mark
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20211103163338

A mark allows to name a point within a zettel.
This is useful if you want to reference some content in a bigger-sized zettel, currently with a [[link|00001007040310]] only[^Other uses of marks will be given, if Zettelmarkup is extended by a concept called //transclusion//.].
This is useful if you want to reference some content in a bigger-sized zettel, currently with a [[link|00001007040310]] only[^Other uses of marks will be given, if Zettelmarkup is extended by a concept called __transclusion__.].

A mark begins with a left square bracket, followed by an exclamation mark character (""''!''"", ''U+0021'').
Now the optional mark name follows.
It is a (possibly empty) sequence of Unicode letters, Unicode digits, the hyphen-minus character (""''-''"", ''U+002D''), or the low-line character (""''_''"", ''U+005F'').
The mark element ends with a right square bracket.

Examples:

id: 00001007050000
title: Zettelmarkup: Attributes
role: manual
tags: #manual #zettelmarkup #zettelstore
syntax: zmk
modified: 20210830161438
modified: 20211103162617

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

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

Attributes are specified within curly brackets ``{...}``.
Of course, more than one attribute can be specified.
Attributes are separated by a sequence of space characters or by a comma character.

An attribute normally consists of an optional key and an optional value.
The key is a sequence of letters, digits, a hyphen-minus (""''-''"", ''U+002D'', and a low line / underscore (""''_''"", ''U+005D'').
It can be empty.
The value is a sequence of any character, except space and the right curly bracket (""''}''"", ''U+007D'').
If the value must contain a space or the right curly bracket, the value can be specified within two quotation marks (""''"''"", ''U+0022'').
Within the quotation marks, the backslash character functions as an escape character to specify the quotation mark (and the backslash character too).

Some examples:

* ``{key=value}`` sets the attribute //key// to value //value//.
* ``{key=value}`` sets the attribute __key__ to value __value__.
* ``{key="value with space"}`` sets the attribute to the given value.
* ``{key="value with quote \\" (and backslash \\\\)"}``
* ``{name}`` sets the attribute //name//. It has no corresponding value. It is
  equivalent to ``{name=}``.
* ``{=key}`` sets the //generic attribute//{-} to the given value. It is mostly
  used for modifying behaviour according to a programming language.
* ``{.key}`` sets the //class attribute//{-} to the given value. It is
  equivalent to ``{class=key}``. 
* ``{name}`` sets the attribute __name__.
  It has no corresponding value.
  It is equivalent to ``{name=}``.
* ``{=key}`` sets the __generic attribute__ to the given value.
  It is mostly used for modifying behaviour according to a programming language.
* ``{.key}`` sets the __class attribute__ to the given value.
  It is equivalent to ``{class=key}``. 

In these examples, ``key`` must conform the the syntax of attribute keys, even if it is used as a value.

If a key is given more than once in an attribute, the values are concatenated (and separated by a space).

* ``{key=value1 key=value2}`` is the same as ``{key"value1 value2"}``.
* ``{key key}`` is the same as ``{key}``.
* ``{.class1 .class2}`` is equivalent to ``{class="class1 class2"}``.

This is not true for the generic attribute.
In ``{=key1 =key2}``, the first key is ignored.
Therefore it is equivalent to ``{=key2}``.

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

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

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

id: 00001007060000
title: Zettelmarkup: Summary of Formatting Characters
role: manual
tags: #manual #reference #zettelmarkup #zettelstore
syntax: zmk
modified: 20210728162830
modified: 20211113180517

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

|= Character :|= Blocks <|= Inlines <
| ''!''  | (free) | (free)
| ''"''  | [[Verse block|00001007030700]] | [[Typographic quotation mark|00001007040100]]
| ''#''  | [[Ordered list|00001007030200]] | [[Tag|00001007040000]]
| ''$''  | (reserved) | (reserved)
| ''%''  | [[Comment block|00001007030900]] | [[Comment|00001007040000]]
| ''&''  | (free) | [[Entity|00001007040000]]
| ''\'''  | (free)  | [[Monospace text|00001007040100]]
| ''(''  | (free) | (free)
| '')''  | (free) | (free)
| ''*''  | [[Unordered list|00001007030200]] | [[strongly emphasized / bold text|00001007040100]]
| ''*''  | [[Unordered list|00001007030200]] | [[strongly emphasized text|00001007040100]]
| ''+''  | (free) | [[Keyboard input|00001007040200]]
| '',''  | (free) | [[Subscripted text|00001007040100]]
| ''-''  | [[Horizonal rule|00001007030400]] | ""[[en-dash|00001007040000]]""
| ''.''  | (free) | [[Horizontal ellipsis|00001007040000]]
| ''/''  | (free) | [[Emphasized / italics text|00001007040100]]
| ''/''  | (free) | [[//Emphasized text//|00001007040100]] (deprecated for v0.2.0)
| '':''  | [[Region block|00001007030800]] / [[description text|00001007030100]] | [[Inline region|00001007040100]]
| '';''  | [[Description term|00001007030100]] | [[Small text|00001007040100]]
| ''<''  | [[Quotation block|00001007030600]] | [[Short inline quote|00001007040100]]
| ''=''  | [[Headings|00001007030300]] | [[Computer output|00001007040200]]
| ''>''  | [[Quotation lists|00001007030200]] | (blocked: to remove anyambiguity with quotation lists)
| ''>''  | [[Quotation lists|00001007030200]] | [[Inserted text|00001007040100]]
| ''?''  | (free) | (free)
| ''@''  | (free) | (reserved)
| ''[''  | (reserved)  | [[Linked material|00001007040300]], [[citation key|00001007040300]], [[footnote|00001007040300]], [[mark|00001007040300]]
| ''\\'' | (blocked by inline meaning) | [[Escape character|00001007040000]]
| '']''  | (reserved) | End of link, citation key, footnote, mark
| ''^''  | (free) | [[Superscripted text|00001007040100]]
| ''_''  | (free) | [[Underlined text|00001007040100]]
| ''_''  | (free) | [[Emphasized text|00001007040100]]
| ''`''  | [[Verbatim block|00001007030500]] | [[Literal text|00001007040200]]
| ''{''  | (reserved) | [[Embedded material|00001007040300]], [[Attribute|00001007050000]]
| ''|''  | [[Table row / table cell|00001007031000]] | Separator within link and embed formatting
| ''}''  | (reserved) | End of embedded material, End of Attribute
| ''~''  | (free) | [[Strike-through text|00001007040100]]
| ''~''  | (free) | [[Deleted text|00001007040100]]

id: 00001010070400
title: Authorization and read-only mode
role: manual
tags: #authorization #configuration #manual #security #zettelstore
syntax: zmk
role: manual
modified: 20211103164251

It is possible to enable both the read-only mode of the Zettelstore //and// authentication/authorization.
It is possible to enable both the read-only mode of the Zettelstore __and__ authentication/authorization.
Both modes are independent from each other.
This gives four use cases:

; Not read-only, no authorization
: Zettelstore runs on your local computer and you only work with it.
; Not read-only, with authorization
: Zettelstore is accessed remotely.

id: 00001010090100
title: External server to encrypt message transport
role: manual
tags: #configuration #encryption #manual #security #zettelstore
syntax: zmk
modified: 20210511131719
modified: 20211027125733

Since Zettelstore does not encrypt the messages it exchanges with its clients, you may need some additional software to enable encryption.

=== Public-key encryption
To enable encryption, you probably use some kind of encryption keys.
In most cases, you need to deploy a ""public-key encryption"" process, where your side publish a public encryption key that only works with a corresponding private decryption key.
Technically, this is not trivial.

  }
}
```
This will forwards requests with the prefix ""/manual/"" to the running Zettelstore.
All other requests will be handled by Caddy itself.

In this case you must specify the [[startup configuration key ''url-prefix''|00001004010000#url-prefix]] with the value ""/manual/"".
This is to allow Zettelstore ignore the prefix while reading web requests and to give the correct URLs with the given prefix when sending a web response.
This is to allow Zettelstore to ignore the prefix while reading web requests and to give the correct URLs with the given prefix when sending a web response.

id: 00001012000000
title: API
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20210908220502
modified: 20211004111103

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.

** [[Content search|00001012051840]]
** [[Sort the list of zettel metadata|00001012052000]]
* [[List all tags|00001012052400]]
* [[List all roles|00001012052600]]

=== Working with zettel
* [[Create a new zettel|00001012053200]]
* [[Retrieve metadata and content of an existing zettel|00001012053400]]
* [[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]]
* [[Retrieve references of an existing zettel|00001012053700]]
* [[Retrieve context of an existing zettel|00001012053800]]
* [[Retrieve zettel order within an existing zettel|00001012054000]]
* [[Update metadata and content of a zettel|00001012054200]]
* [[Rename a zettel|00001012054400]]
* [[Delete a zettel|00001012054600]]

=== Various helper method
* [[Encode Zettelmarkup inline material as HTML/Text|00001012070500]]

id: 00001012051200
title: API: List metadata of all zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20210905203616
modified: 20211004124401

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
{"list":[{"id":"00001012051200","meta":{"title":"API: Renew an access token","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"}},{"id":"00001012050600","meta":{"title":"API: Provide an access token","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"}},{"id":"00001012050400","meta":{"title":"API: Renew an access token","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"}},{"id":"00001012050200","meta":{"title":"API: Authenticate a client","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"}},{"id":"00001012000000","meta":{"title":"API","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"}}]}
{"query":"","list":[{"id":"00001012051200","meta":{"title":"API: Renew an access token","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"}},{"id":"00001012050600","meta":{"title":"API: Provide an access token","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"}},{"id":"00001012050400","meta":{"title":"API: Renew an access token","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"}},{"id":"00001012050200","meta":{"title":"API: Authenticate a client","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"}},{"id":"00001012000000","meta":{"title":"API","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual"}}]}
```

The JSON object contains a key ''"list"'' where its value is a list of zettel JSON objects.
These zettel JSON objects themself contains the keys ''"id"'' (value is a string containing the zettel identifier), , and ''"meta"'' (value as a JSON object).
These zettel JSON objects themselves contains the keys ''"id"'' (value is a string containing the zettel identifier), , and ''"meta"'' (value as a JSON object).
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.

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

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

id: 00001012051800
title: API: Shape the list of zettel metadata
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20210905203719
modified: 20211103162259

In most cases, it is not essential to list //all// zettel.
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]].
* [[Searching for specific content|00001012051840]], not just the 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: 20210905203929
modified: 20211103164030

Every query parameter that does //not// begin with the low line character (""_"", ''U+005F'') is treated as the name of a [[metadata|00001006010000]] key.
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'
{"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"}}, ...
{"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'').
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'
{"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"}},
{"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.
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.

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.

id: 00001012051830
title: API: Shape the list of zettel metadata by limiting its length
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20210905204006
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'
{"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 00001012053400 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"}}]}
{"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'
{"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"}}]}
{"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: 00001012053300
title: Retrieve metadata and content of an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20211004111804

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 (14 digits).

For example, to retrieve some data about this zettel you are currently viewing, just send a HTTP GET request to the endpoint ''/j/00001012053300''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header].
If successful, the output is a JSON object:
```sh
# curl http://127.0.0.1:23123/j/00001012053300
{"id":"00001012053300","meta":{"title":"API: Retrieve data for an exisiting zettel","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual","copyright":"(c) 2020 by Detlef Stern <ds@zettelstore.de>","lang":"en","license":"CC BY-SA 4.0"},"content":"The endpoint to work with a specific zettel is ''/j/{ID}'', where ''{ID}'' is a placeholder for the zettel identifier (14 digits).\n\nFor example, ...
```

Pretty-printed, this results in:
```
{
  "id": "00001012053300",
  "meta": {
    "back": "00001012000000 00001012053200 00001012054400",
    "backward": "00001012000000 00001012053200 00001012054400 00001012920000",
    "box-number": "1",
    "forward": "00001010040100 00001012050200 00001012920000 00001012920800",
    "modified": "20210726190012",
    "published": "20210726190012",
    "role": "manual",
    "syntax": "zmk",
    "tags": "#api #manual #zettelstore",
    "title": "API: Retrieve metadata and content of an existing zettel"
  },
  "encoding": "",
  "content": "The [[endpoint|00001012920000]] to work with metadata and content of a specific zettel is ''/j/{ID}'', where ''{ID}'' (...)
}
```

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

````sh
# 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 (14 digits).

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'
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 (14 digits).

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.
; ''400''
: Request was not valid. 
  There are several reasons for this.
  Maybe the zettel identifier did not consist 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 and content of an existing zettel
title: API: Retrieve metadata of an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20210905204428
modified: 20211004112257

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 (14 digits).
The [[endpoint|00001012920000]] to work with metadata of a specific zettel is ''/m/{ID}'', where ''{ID}'' is a placeholder for the zettel identifier (14 digits).

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/j/00001012053400
{"id":"00001012053400","meta":{"title":"API: Retrieve data for an exisiting zettel","tags":"#api #manual #zettelstore","syntax":"zmk","role":"manual","copyright":"(c) 2020 by Detlef Stern <ds@zettelstore.de>","lang":"en","license":"CC BY-SA 4.0"},"content":"The endpoint to work with a specific zettel is ''/j/{ID}'', where ''{ID}'' is a placeholder for the zettel identifier (14 digits).\n\nFor example, ...
# curl http://127.0.0.1:23123/m/00001012053400
{"meta":{"all-tags":"#api #manual #zettelstore","back":"00001012000000 00001012053300","backward":"00001012000000 00001012053300 00001012920000","box-number":"1","forward":"00001010040100 00001012050200 00001012920000 00001012920800","modified":"20211004111240","published":"20211004111240","role":"manual","syntax":"zmk","tags":"#api #manual #zettelstore","title":"API: Retrieve metadata of an existing zettel"}}
```

Pretty-printed, this results in:
```
{
  "id": "00001012053400",
  "meta": {
    "all-tags": "#api #manual #zettelstore",
    "back": "00001012000000 00001012053200 00001012054400",
    "backward": "00001012000000 00001012053200 00001012054400 00001012920000",
    "back": "00001012000000 00001012053300",
    "backward": "00001012000000 00001012053300 00001012920000",
    "box-number": "1",
    "forward": "00001010040100 00001012050200 00001012920000 00001012920800",
    "modified": "20210726190012",
    "published": "20210726190012",
    "modified": "20211004111240",
    "published": "20211004111240",
    "role": "manual",
    "syntax": "zmk",
    "tags": "#api #manual #zettelstore",
    "title": "API: Retrieve metadata and content of an existing zettel"
    "title": "API: Retrieve metadata of an existing zettel"
  },
  "encoding": "",
  "content": "The [[endpoint|00001012920000]] to work with metadata and content of a specific zettel is ''/j/{ID}'', where ''{ID}'' (...)
  }
}
```

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

````sh
# curl 'http://127.0.0.1:23123/z/00001012053400'
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 (14 digits).

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
...
````

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

=== HTTP Status codes
; ''200''

id: 00001012053500
title: API: Retrieve evaluated metadata and content of an existing zettel in various encodings
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20210826224328
modified: 20211028191044

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 (14 digits).

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

<meta name="zs-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="/v/00001012920000?_enc=html">endpoint</a> to work with metadata and content of a specific zettel is <span style="font-family:monospace">/v/{ID}</span>, where <span style="font-family:monospace">{ID}</span> is a placeholder for the zettel identifier (14 digits).</p>
<p>The <a href="00001012920000">endpoint</a> to work with evaluated metadata and content of a specific zettel is <span class="zs-monospace">/v/{ID}</span>, where <span class="zs-monospace">{ID}</span> is a placeholder for the zettel identifier (14 digits).</p>
...
```

You also can use the query parameter ''_part=[[PART|00001012920800]]'' to specify which parts 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'

id: 00001012053600
title: API: Retrieve parsed metadata and content of an existing zettel in various encodings
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20210830165056
modified: 20211103164337

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 (14 digits).

A //parsed// zettel is basically an [[unevaluated|00001012053500]] zettel: the zettel is read and analyzed, but its content is //not evaluated//.
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].
If successful, the output is a JSON object:
```sh
# curl http://127.0.0.1:23123/p/00001012053600
{"meta":{"title":[{"t":"Text","s":"Retrieve"},{"t":"Space"},{"t":"Text","s":"parsed"},{"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"},{"t":"Text","s":"various"},{"t":"Space"},{"t":"Text","s":"encodings"}],"role":"manual","tags":["#api", ...

id: 00001012053800
title: API: Retrieve context of an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20210825194347
modified: 20211103163027

The context of an origin zettel consists of those zettel that are somehow connected to the origin zettel.
Direct connections of an origin zettel to other zettel are visible via [[metadata values|00001006020000]], such as ''backward'', ''forward'' or other values with type [[identifier|00001006032000]] or [[set of identifier|00001006032500]].
Zettel are also connected by using same [[tags|00001006020000#tags]].

The context is defined by a //direction//, a //depth//, and a //limit//:
The context is defined by a __direction__, a __depth__, and a __limit__:
* Direction: connections are directed.
  For example, the metadata value of ''backward'' lists all zettel that link to the current zettel, while ''formward'' list all zettel to which the current zettel links.
  When you are only interested in one direction, set the parameter ''dir'' either to the value ""backward"" or ""forward"".
  All other values, including a missing value, is interpreted as ""both"".
* Depth: a direct connection has depth 1, an indirect connection is the length of the shortest path between two zettel.
  You should limit the depth by using the parameter ''depth''.
  Its default value is ""5"".
  A value of ""0"" does disable any depth check.
* Limit: to set an upper bound for the returned context, you should use the parameter ''limit''.
  Its default value is ""200"".
  A value of ""0"" disables does not limit the number of elements returned.

Zettel with same tags as the origin zettel are considered depth 1.
Only for the origin zettel, tags are used to calculate a connection.
Currently, only some of the newest zettel with a given tag are considered a connection.[^The number of zettel is given by the value of parameter ''depth''.]
Otherwise the context would become too big and therefore unusable.
The search for the context of a zettel stops at the [[home zettel|00001004020000#home-zettel]].
This zettel is connected to all other zettel.
If it is included, the context would become too big and therefore unusable.

To retrieve the context of an existing zettel, use the [[endpoint|00001012920000]] ''/x/{ID}''[^Mnemonic: conte**X**t].

````
# curl 'http://127.0.0.1:23123/x/00001012053800?limit=3&dir=forward&depth=2'
{"id": "00001012053800","meta": {...},"list": [{"id": "00001012921000","meta": {...}},{"id": "00001012920800","meta": {...}},{"id": "00010000000000","meta": {...}}]}
````

id: 00001012054400
title: API: Rename a zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
modified: 20210905204715
modified: 20211004111301

Renaming a zettel is effectively just specifying a new identifier for the zettel.
Since more than one [[box|00001004011200]] might contain a zettel with the old identifier, the rename operation must success in every relevant box to be overall successful.
If the rename operation fails in one box, Zettelstore tries to rollback previous successful operations.

As a consequence, you cannot rename a zettel when its identifier is used in a read-only box.
This applies to all predefined zettel, for example.

The [[endpoint|00001012920000]] to rename a zettel is ''/j/{ID}'', where ''{ID}'' is a placeholder for the zettel identifier (14 digits).
You must send a HTTP MOVE request to this endpoint, and you must specify the new zettel identifier as an URL, placed under the HTTP request header key ''Destination''.
```
# curl -X MOVE -H "Destination: 10000000000001" http://127.0.0.1:23123/j/00001000000000
```

Only the last 14 characters of the value of ''Destination'' are taken into account and those must form an unused zettel identifier.
If the value contains less than 14 characters that do not form an unused zettel identifier, the response will contain a HTTP status code ''400''.
All other characters, besides those 14 digits, are effectively ignored.
However, the value should form a valid URL that could be used later to [[read the content|00001012053400]] of the freshly renamed zettel.
However, the value should form a valid URL that could be used later to [[read the content|00001012053300]] of the freshly renamed zettel.

[!plain]Alternatively, you can also use the [[endpoint|00001012920000]] ''/z/{ID}''.
Both endpoints behave identical.

=== HTTP Status codes
; ''204''
: Rename was successful, there is no body in the response.

id: 00001012070500
title: API: Encode Zettelmarkup inline material as HTML/Text
role: zettel
tags: #api #manual #zettelstore
syntax: zmk
modified: 20211111145202

To encode [[Zettelmarkup inline material|00001007040000]] send a HTTP POST request to the [[endpoint|00001012920000]] ''/v''.
The POST body must contain a JSON encoded list of Zettelmarkup inline material to be encoded:

; ''first-zmk''
: Contains the first Zettelmarkup encoded material.
  This will be encoded as [[HTML|00001012920510]] and [[Text|00001012920519]].
; ''other-zmk''
: Contain more material.
  The list can be empty.
  These will be encoded in HTML only.
; ''lang''
: Specifies the language for HTML encoding.
  If empty, the default language of the Zettelstore instance will be used.
; ''no-links''
: A boolean value, which specifies whether links should be encoded (``"no-links":false``) or should be not encoded (``"no-links":true``).
  Default: ''false''.

Typically, this call will be used to encode the [[title|00001006020000#title]] of a zettel.

If successful, the call will return the following JSON document:

; ''first-html''
: HTML encoding of ''first-zmk''
; ''first-text''
: Text encoding of ''first-zmk''
; ''other_html''
: HTML encoding of the corresponding value in ''other-zmk''.

Encoding takes place in the context of all other zettel in the Zettelstore.
For example, links and images are evaluated according to this context.

A simple example:
```sh
# curl -X POST --data '{"first-zmk":"hallo [[00000000000001]]"}' http://127.0.0.1:23123/v
{"first-html":"hallo <a href=\"00000000000001\">00000000000001</a>","first-text":"hallo ","other-html":null}

# curl -X POST --data '{"first-zmk":"hallo [[00000000000001]]","no-links":true}' http://127.0.0.1:23123/v
{"first-html":"hallo <span>00000000000001</span>","first-text":"hallo ","other-html":null}
```

=== HTTP Status codes
; ''200''
: Operation was successful, the body contains a JSON object as described above.
; ''400''
: Request was not valid. 
  There are several reasons for this.
  Most likely, the JSON was not formed according to above rules.
; ''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
modified: 20210908220438
modified: 20211004111932

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 ressource 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|00001012053400]] | **J**SON
| ''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]]
| ''l'' |  | GET: [[list references|00001012053700]] | **L**inks
| ''m'' |  | GET: [[retrieve metadata|00001012053400]] | **M**etadata
| ''o'' |  | GET: [[list zettel order|00001012054000]] | **O**rder
| ''p'' |  | GET: [[retrieve parsed zettel|00001012053600]]| **P**arsed
| ''r'' | GET: [[list roles|00001012052600]] | | **R**oles
| ''t'' | GET: [[list tags|00001012052400]] || **T**ags
| ''v'' |  | GET: [[retrieve evaluated zettel|00001012053500]] | E**v**aluated
| ''v'' | POST: [[encode inlines|00001012070500]] | GET: [[retrieve evaluated zettel|00001012053500]] | E**v**aluated
| ''x'' |  | GET: [[list zettel context|00001012053800]] | Conte**x**t
| ''z'' | GET: [[list zettel|00001012051200#plain]] | GET: [[retrieve zettel|00001012053400#plain]] | **Z**ettel
| ''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: 00001018000000
title: Troubleshooting
role: zettel
tags: #manual #zettelstore
syntax: zmk
modified: 20211027125603

This page lists some problems and their solutions that may occur when using your 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 ''http**s**:/\/'', 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 ''http**s**:/\/'' schema.

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

// Package domain provides domain specific types, constants, and functions.
package domain

import (
	"bytes"
	"encoding/base64"
	"errors"
	"io"
	"unicode/utf8"

	"unicode"
	"unicode/utf8"
	"zettelstore.de/z/strfun"
)

// Content is just the content of a zettel.
type Content struct {
	data     string
	data     []byte
	isBinary bool
}

// NewContent creates a new content from a string.
func NewContent(s string) Content {
	return Content{data: s, isBinary: calcIsBinary(s)}
func NewContent(data []byte) Content {
	return Content{data: data, isBinary: calcIsBinary(data)}
}

// Equal compares two content values.
func (zc *Content) Equal(o *Content) bool {
	if zc == nil {
		return o == nil
	}
	if zc.isBinary != o.isBinary {
		return false
	}
	return bytes.Equal(zc.data, o.data)
}

// Set content to new string value.
func (zc *Content) Set(s string) {
	zc.data = s
	zc.isBinary = calcIsBinary(s)
func (zc *Content) Set(data []byte) {
	zc.data = data
	zc.isBinary = calcIsBinary(data)
}

// Write it to a Writer
func (zc *Content) Write(w io.Writer) (int, error) {
	return io.WriteString(w, zc.data)
	return w.Write(zc.data)
}

// AsString returns the content itself is a string.
func (zc *Content) AsString() string { return zc.data }
func (zc *Content) AsString() string { return string(zc.data) }

// AsBytes returns the content itself is a byte slice.
func (zc *Content) AsBytes() []byte { return []byte(zc.data) }
func (zc *Content) AsBytes() []byte { return zc.data }

// IsBinary returns true if the content contains non-unicode values or is,
// interpreted a text, with a high probability binary content.
func (zc *Content) IsBinary() bool { return zc.isBinary }

// TrimSpace remove some space character in content, if it is not binary content.
func (zc *Content) TrimSpace() {
	if zc.isBinary {
		return
	}
	zc.data = strfun.TrimSpaceRight(zc.data)
	zc.data = bytes.TrimRightFunc(zc.data, unicode.IsSpace)
}

// Encode content for future transmission.
func (zc *Content) Encode() (data, encoding string) {
	if !zc.isBinary {
		return zc.data, ""
		return zc.AsString(), ""
	}
	return base64.StdEncoding.EncodeToString([]byte(zc.data)), "base64"
	return base64.StdEncoding.EncodeToString(zc.data), "base64"
}

// SetDecoded content to the decoded value of the given string.
func (zc *Content) SetDecoded(data, encoding string) error {
	switch encoding {
	case "":
		zc.data = data
		zc.data = []byte(data)
	case "base64":
		decoded, err := base64.StdEncoding.DecodeString(data)
		if err != nil {
			return err
		}
		zc.data = string(decoded)
		zc.data = decoded
	default:
		return errors.New("unknown encoding " + encoding)
	}
	zc.isBinary = calcIsBinary(zc.data)
	return nil
}

func calcIsBinary(s string) bool {
	if !utf8.ValidString(s) {
func calcIsBinary(data []byte) bool {
	if !utf8.Valid(data) {
		return true
	}
	l := len(s)
	l := len(data)
	for i := 0; i < l; i++ {
		if s[i] == 0 {
		if data[i] == 0 {
			return true
		}
	}
	return false
}

	}{
		{"abc", false},
		{"äöü", false},
		{"", false},
		{string([]byte{0}), true},
	}
	for i, tc := range td {
		content := domain.NewContent(tc.s)
		content := domain.NewContent([]byte(tc.s))
		got := content.IsBinary()
		if got != tc.exp {
			t.Errorf("TC=%d: expected %v, got %v", i, tc.exp, got)
		}
	}
}

// Package id provides domain specific types, constants, and functions about
// zettel identifier.
package id

import (
	"strconv"
	"time"

	"zettelstore.de/c/api"
)

// Zid is the internal identifier of a zettel. Typically, it is a
// time stamp of the form "YYYYMMDDHHmmSS" converted to an unsigned integer.
// A zettelstore implementation should try to set the last two digits to zero,
// e.g. the seconds should be zero,
type Zid uint64

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

	// System zettel
)

	VersionZid              = Zid(1)
	HostZid                 = Zid(2)
// ZettelIDs that are used as Zid more than once.
	OperatingSystemZid      = Zid(3)
	LicenseZid              = Zid(4)
	AuthorsZid              = Zid(5)
// 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.
	DependenciesZid         = Zid(6)
	BoxManagerZid           = Zid(20)
	MetadataKeyZid          = Zid(90)
	StartupConfigurationZid = Zid(96)
	ConfigurationZid        = Zid(100)
var (
	ConfigurationZid   = MustParse(api.ZidConfiguration)

	// WebUI HTML templates are in the range 10000..19999
	BaseTemplateZid    = Zid(10100)
	LoginTemplateZid   = Zid(10200)
	ListTemplateZid    = Zid(10300)
	ZettelTemplateZid  = Zid(10401)
	InfoTemplateZid    = Zid(10402)
	FormTemplateZid    = Zid(10403)
	RenameTemplateZid  = Zid(10404)
	DeleteTemplateZid  = Zid(10405)
	ContextTemplateZid = Zid(10406)
	RolesTemplateZid   = Zid(10500)
	TagsTemplateZid    = Zid(10600)
	ErrorTemplateZid   = Zid(10700)

	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)
	EmojiZid           = MustParse(api.ZidEmoji)
	// WebUI CSS zettel are in the range 20000..29999
	BaseCSSZid = Zid(20001)
	UserCSSZid = Zid(25001)

	// WebUI JS zettel are in the range 30000..39999

	// WebUI image zettel are in the range 40000..49999
	EmojiZid = Zid(40001)

	// Range 90000...99999 is reserved for zettel templates
	TOCNewTemplateZid    = Zid(90000)
	TOCNewTemplateZid  = MustParse(api.ZidTOCNewTemplate)
	TemplateNewZettelZid = Zid(90001)
	TemplateNewUserZid   = Zid(90002)

	DefaultHomeZid = Zid(10000000000)
	DefaultHomeZid     = MustParse(api.ZidDefaultHome)
)

const maxZid = 99999999999999

// ParseUint interprets a string as a possible zettel identifier
// and returns its integer value.
func ParseUint(s string) (uint64, error) {

	}
	res, err := ParseUint(s)
	if err != nil {
		return Invalid, err
	}
	return Zid(res), nil
}

// MustParse tries to interpret a string as a zettel identifier and returns
// its value or panics otherwise.
func MustParse(s api.ZettelID) Zid {
	zid, err := Parse(string(s))
	if err == nil {
		return zid
	}
	panic(err)
}

const digits = "0123456789"

// String converts the zettel identification to a string of 14 digits.
// Only defined for valid ids.
func (zid Zid) String() string {
	return string(zid.Bytes())
}

// Bytes converts the zettel identification to a byte slice of 14 digits.
// Only defined for valid ids.
func (zid Zid) Bytes() []byte {
	n := uint64(zid)
	result := make([]byte, 14)
	for i := 13; i >= 0; i-- {
		result[i] = digits[zid%10]
		zid /= 10
		result[i] = digits[n%10]
		n /= 10
	}
	return result
}

// 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 }

		zid, err := id.Parse(sid)
		if err != nil {
			t.Errorf("i=%d: sid=%q is not valid, but should be. err=%v", i, sid, err)
		}
		s := zid.String()
		if s != sid {
			t.Errorf(
				"i=%d: zid=%v does not format to %q, but to %q", i, sid, zid, s)
				"i=%d: zid=%v does not format to %q, but to %q", i, zid, sid, s)
		}
	}

	invalidIDs := []string{
		"", "0", "a",
		"00000000000000",
		"0000000000000a",

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

// Package id provides domain specific types, constants, and functions about
// zettel identifier.
package id

import (
	"bytes"
	"sort"
	"strings"
)

// Slice is a sequence of zettel identifier. A special case is a sorted slice.
type Slice []Zid

func (zs Slice) Len() int           { return len(zs) }
func (zs Slice) Less(i, j int) bool { return zs[i] < zs[j] }

	return true
}

func (zs Slice) String() string {
	if len(zs) == 0 {
		return ""
	}
	var sb strings.Builder
	var buf bytes.Buffer
	for i, zid := range zs {
		if i > 0 {
			sb.WriteByte(' ')
			buf.WriteByte(' ')
		}
		sb.WriteString(zid.String())
		buf.WriteString(zid.String())
	}
	return sb.String()
	return buf.String()
}

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

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

import (
	"bytes"
	"regexp"
	"sort"
	"strings"
	"unicode"
	"unicode/utf8"

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

type keyUsage int

const (

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 }

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

func registerKey(name string, t *DescriptionType, usage keyUsage, inverse string) string {
func registerKey(name string, t *DescriptionType, usage keyUsage, inverse string) {
	if _, ok := registeredKeys[name]; ok {
		panic("Key '" + name + "' already defined")
	}
	if inverse != "" {
		if t != TypeID && t != TypeIDSet {
			panic("Inversable key '" + name + "' is not identifier type, but " + t.String())
		}
		inv, ok := registeredKeys[inverse]
		if !ok {
			panic("Inverse Key '" + inverse + "' not found")
		}
		if !inv.IsComputed() {
			panic("Inverse Key '" + inverse + "' is not computed.")
		}
		if inv.Type != TypeIDSet {
			panic("Inverse Key '" + inverse + "' is not an identifier set, but " + inv.Type.String())
		}
	}
	registeredKeys[name] = &DescriptionKey{name, t, usage, inverse}
	return name
}

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

	for _, n := range names {
		result = append(result, registeredKeys[n])
	}
	return result
}

// Supported keys.
var (
	KeyID                = registerKey("id", TypeID, usageComputed, "")
	KeyTitle             = registerKey("title", TypeZettelmarkup, usageUser, "")
	KeyRole              = registerKey("role", TypeWord, usageUser, "")
	KeyTags              = registerKey("tags", TypeTagSet, usageUser, "")
	KeySyntax            = registerKey("syntax", TypeWord, usageUser, "")
	KeyAllTags           = registerKey("all-"+KeyTags, TypeTagSet, usageProperty, "")
	KeyBack              = registerKey("back", TypeIDSet, usageProperty, "")
	KeyBackward          = registerKey("backward", TypeIDSet, usageProperty, "")
	KeyBoxNumber         = registerKey("box-number", TypeNumber, usageComputed, "")
	KeyCopyright         = registerKey("copyright", TypeString, usageUser, "")
	KeyCredential        = registerKey("credential", TypeCredential, usageUser, "")
	KeyDead              = registerKey("dead", TypeIDSet, usageProperty, "")
	KeyDefaultCopyright  = registerKey("default-copyright", TypeString, usageUser, "")
	KeyDefaultLang       = registerKey("default-lang", TypeWord, usageUser, "")
	KeyDefaultLicense    = registerKey("default-license", TypeEmpty, usageUser, "")
	KeyDefaultRole       = registerKey("default-role", TypeWord, usageUser, "")
	KeyDefaultSyntax     = registerKey("default-syntax", TypeWord, usageUser, "")
	KeyDefaultTitle      = registerKey("default-title", TypeZettelmarkup, usageUser, "")
	KeyDefaultVisibility = registerKey("default-visibility", TypeWord, usageUser, "")
	KeyDuplicates        = registerKey("duplicates", TypeBool, usageUser, "")
	KeyExpertMode        = registerKey("expert-mode", TypeBool, usageUser, "")
	KeyFolge             = registerKey("folge", TypeIDSet, usageProperty, "")
	KeyFooterHTML        = registerKey("footer-html", TypeString, usageUser, "")
	KeyForward           = registerKey("forward", TypeIDSet, usageProperty, "")
	KeyHomeZettel        = registerKey("home-zettel", TypeID, usageUser, "")
	KeyLang              = registerKey("lang", TypeWord, usageUser, "")
	KeyLicense           = registerKey("license", TypeEmpty, usageUser, "")
	KeyMarkerExternal    = registerKey("marker-external", TypeEmpty, usageUser, "")
	KeyMaxTransclusions  = registerKey("max-transclusions", TypeNumber, usageUser, "")
	KeyModified          = registerKey("modified", TypeTimestamp, usageComputed, "")
	KeyNoIndex           = registerKey("no-index", TypeBool, usageUser, "")
func init() {
	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.KeyBack, TypeIDSet, usageProperty, "")
	registerKey(api.KeyBackward, TypeIDSet, usageProperty, "")
	registerKey(api.KeyBoxNumber, TypeNumber, usageComputed, "")
	registerKey(api.KeyContentTags, TypeTagSet, usageProperty, "")
	registerKey(api.KeyCopyright, TypeString, usageUser, "")
	registerKey(api.KeyCredential, TypeCredential, usageUser, "")
	registerKey(api.KeyDead, TypeIDSet, usageProperty, "")
	registerKey(api.KeyDuplicates, TypeBool, 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, "")
	registerKey(api.KeyNoIndex, TypeBool, usageUser, "")
	registerKey(api.KeyPrecursor, TypeIDSet, usageUser, api.KeyFolge)
	registerKey(api.KeyPublished, TypeTimestamp, usageProperty, "")
	registerKey(api.KeyReadOnly, TypeWord, usageUser, "")
	registerKey(api.KeyURL, TypeURL, usageUser, "")
	registerKey(api.KeyUserID, TypeWord, usageUser, "")
	registerKey(api.KeyUserRole, TypeWord, usageUser, "")
	registerKey(api.KeyVisibility, TypeWord, usageUser, "")

	// Keys for runtime configuration zettel
	// See: https://zettelstore.de/manual/h/00001004020000
	registerKey(api.KeyDefaultCopyright, TypeString, usageUser, "")
	registerKey(api.KeyDefaultLang, TypeWord, usageUser, "")
	registerKey(api.KeyDefaultLicense, TypeEmpty, usageUser, "")
	registerKey(api.KeyDefaultRole, TypeWord, usageUser, "")
	registerKey(api.KeyDefaultSyntax, TypeWord, usageUser, "")
	registerKey(api.KeyDefaultTitle, TypeZettelmarkup, usageUser, "")
	registerKey(api.KeyDefaultVisibility, TypeWord, usageUser, "")
	registerKey(api.KeyExpertMode, TypeBool, usageUser, "")
	KeyPrecursor         = registerKey("precursor", TypeIDSet, usageUser, KeyFolge)
	KeyPublished         = registerKey("published", TypeTimestamp, usageProperty, "")
	KeyReadOnly          = registerKey("read-only", TypeWord, usageUser, "")
	KeySiteName          = registerKey("site-name", TypeString, usageUser, "")
	KeyURL               = registerKey("url", TypeURL, usageUser, "")
	KeyUserID            = registerKey("user-id", TypeWord, usageUser, "")
	KeyUserRole          = registerKey("user-role", TypeWord, usageUser, "")
	KeyVisibility        = registerKey("visibility", TypeWord, usageUser, "")
	KeyYAMLHeader        = registerKey("yaml-header", TypeBool, usageUser, "")
	KeyZettelFileSyntax  = registerKey("zettel-file-syntax", TypeWordSet, usageUser, "")
	registerKey(api.KeyFooterHTML, TypeString, usageUser, "")
	registerKey(api.KeyHomeZettel, TypeID, usageUser, "")
	registerKey(api.KeyMarkerExternal, TypeEmpty, usageUser, "")
	registerKey(api.KeyMaxTransclusions, TypeNumber, usageUser, "")
	registerKey(api.KeySiteName, TypeString, usageUser, "")
	registerKey(api.KeyYAMLHeader, TypeBool, usageUser, "")
	registerKey(api.KeyZettelFileSyntax, TypeWordSet, usageUser, "")
)
}

// NewPrefix is the prefix for metadata key in template zettel for creating new zettel.
const NewPrefix = "new-"

// Important values for some keys.
const (
	ValueRoleConfiguration = "configuration"
	ValueRoleUser          = "user"
	ValueRoleZettel        = "zettel"
	ValueSyntaxNone        = "none"
	ValueSyntaxGif         = "gif"
	ValueSyntaxText        = "text"
	ValueSyntaxZmk         = "zmk"
	ValueTrue              = "true"
	ValueFalse             = "false"
	ValueLangEN            = "en"
	ValueUserRoleCreator   = "creator"
	ValueUserRoleReader    = "reader"
	ValueUserRoleWriter    = "writer"
	ValueUserRoleOwner     = "owner"
	ValueVisibilityCreator = "creator"
	ValueVisibilityExpert  = "expert"
	ValueVisibilityOwner   = "owner"
	ValueVisibilityLogin   = "login"
	ValueVisibilityPublic  = "public"
)

// Meta contains all meta-data of a zettel.
type Meta struct {
	Zid     id.Zid
	pairs   map[string]string
	YamlSep bool
}