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://mastodon.social/tags/Zettelstore) …

0.13.0

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

package ast

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

// Definition of Block nodes.

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

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

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

package ast

import (
	"unicode/utf8"

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

// Definitions of inline nodes.

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

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

package ast_test

import (
	"testing"

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

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

//-----------------------------------------------------------------------------
// Copyright (c) 2023-present Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//-----------------------------------------------------------------------------

package impl

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

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

var encoding = base64.RawURLEncoding

const digestAlg = crypto.SHA384

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

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

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

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

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

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

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

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

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

	}
	return h.Sum(nil)
}

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

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

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

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

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

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

	now := time.Now().Round(time.Second)
	sClaim := sx.MakeList(
		sx.Int64(kind),
		sx.MakeString(subject),
		sx.Int64(now.Unix()),
		sx.Int64(now.Add(d).Unix()),



		sx.Int64(ident.Zid),
	)




	return sign(sClaim, a.secret)


}

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

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

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

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

func setupTokenData(obj sx.Object, k auth.TokenKind, tokenData *auth.TokenData) error {
	vals, err := sexp.ParseList(obj, "isiii")
	if err != nil {
		return ErrMalformedToken
	}



	if auth.TokenKind(vals[0].(sx.Int64)) != k {
		return ErrOtherKind
	}
	ident := vals[1].(sx.String)
	if ident == "" {
		return ErrNoIdent
	}
	issued := time.Unix(int64(vals[2].(sx.Int64)), 0)
	expires := time.Unix(int64(vals[3].(sx.Int64)), 0)




	now := time.Now().Round(time.Second)

	if expires.Before(now) {
		return ErrTokenExpired


	}
	zid := id.Zid(vals[4].(sx.Int64))
	if !zid.IsValid() {

		return ErrNoZid
	}

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

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

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

	return zettel.Zettel{}, box.NewErrNotAllowed("GetZettel", user, zid)
}

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

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

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









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

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

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

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

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

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

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

func (pp *polBox) Refresh(ctx context.Context) error {
	user := server.GetUser(ctx)

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

package policy

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

type defaultPolicy struct {
	manager auth.AuthzManager
}

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

package policy

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

type ownerPolicy struct {
	manager    auth.AuthzManager

package policy

import (
	"fmt"
	"testing"

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

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

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

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

// BaseBox is implemented by all Zettel boxes.

	// CreateZettel creates a new zettel.
	// Returns the new zettel id (and an error indication).
	CreateZettel(ctx context.Context, zettel zettel.Zettel) (id.Zid, error)

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




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

	// UpdateZettel updates an existing zettel.
	UpdateZettel(ctx context.Context, zettel zettel.Zettel) error

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

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

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

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

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

	// ReadStats populates st with box statistics

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

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

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

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

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




	// Refresh the data from the box and from its managed sub-boxes.
	Refresh(context.Context) error
}

// Stats record stattistics about a box.
type Stats struct {

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

import (
	"context"
	"net/url"

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

}

func (cb *compBox) GetZettel(_ context.Context, zid id.Zid) (zettel.Zettel, error) {
	if gen, ok := myZettel[zid]; ok && gen.meta != nil {
		if m := gen.meta(zid); m != nil {
			updateMeta(m)
			if genContent := gen.content; genContent != nil {
				cb.log.Trace().Msg("GetZettel/Content")
				return zettel.Zettel{
					Meta:    m,
					Content: zettel.NewContent(genContent(m)),
				}, nil
			}
			cb.log.Trace().Msg("GetZettel/NoContent")
			return zettel.Zettel{Meta: m}, nil
		}
	}
	cb.log.Trace().Err(box.ErrNotFound).Msg("GetZettel/Err")
	return zettel.Zettel{}, box.ErrNotFound
}

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




	return found





}

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

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

package compbox

import (
	"bytes"

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

func genConfigZettelM(zid id.Zid) *meta.Meta {
	if myConfig == nil {

package compbox

import (
	"bytes"
	"fmt"

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

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

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

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

package compbox

import (
	"bytes"

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

func genLogM(zid id.Zid) *meta.Meta {
	m := meta.New(zid)

package compbox

import (
	"bytes"
	"fmt"

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

func genManagerM(zid id.Zid) *meta.Meta {
	m := meta.New(zid)

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

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

func genParserM(zid id.Zid) *meta.Meta {

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

package compbox

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

func getVersionMeta(zid id.Zid, title string) *meta.Meta {
	m := meta.New(zid)

        (a (@ (href ,list-tags-url)) "List Tags")
        ,@(if (bound? 'refresh-url) `((a (@ (href ,refresh-url)) "Refresh")))
    ))
    ,@(if new-zettel-links
      `((div (@ (class "zs-dropdown"))
        (button "New")
        (nav (@ (class "zs-dropdown-content"))
          ,@(map wui-link new-zettel-links)
       )))
    )
    (form (@ (action ,search-url))
      (input (@ (type "text") (placeholder "Search..") (name ,query-key-query))))
  )
  (main (@ (class "content")) ,DETAIL)
  ,@(if FOOTER `((footer (hr) ,@FOOTER)))

package constbox

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

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

		cb.log.Trace().Msg("GetZettel")
		return zettel.Zettel{Meta: meta.NewWithData(zid, z.header), Content: z.content}, nil
	}
	cb.log.Trace().Err(box.ErrNotFound).Msg("GetZettel")
	return zettel.Zettel{}, box.ErrNotFound
}

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




	return found
}

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

		zettel.NewContent(contentZettelSxn)},
	id.InfoTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Info HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20200804111624",
			api.KeyModified:   "20230621131500",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentInfoSxn)},
	id.FormTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Form HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20200804111624",
			api.KeyModified:   "20230621132600",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentFormSxn)},
	id.RenameTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Rename Form HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20200804111624",
			api.KeyModified:   "20230707190246",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentRenameSxn)},
	id.DeleteTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Delete HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20200804111624",
			api.KeyModified:   "20230621133100",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentDeleteSxn)},
	id.ListTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore List Zettel HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20230704122100",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentListZettelSxn)},
	id.ErrorTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Error HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20210305133215",
			api.KeyModified:   "20230527224800",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentErrorSxn)},
	id.TemplateSxnZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Sxn Code for Templates",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxSxn,
			api.KeyCreated:    "20230619132800",
			api.KeyVisibility: api.ValueVisibilityExpert,
		},
		zettel.NewContent(contentTemplateCodeSxn)},
	id.MustParse(api.ZidBaseCSS): {
		constHeader{
			api.KeyTitle:      "Zettelstore Base CSS",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     meta.SyntaxCSS,
			api.KeyCreated:    "20200804111624",
			api.KeyVisibility: api.ValueVisibilityPublic,

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

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

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

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

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

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

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

`(article
  (header (h1 "Delete Zettel " ,zid))
  (p "Do you really want to delete this zettel?")
  ,@(if shadowed-box
    `((div (@ (class "zs-info"))
      (h2 "Information")
      (p "If you delete this zettel, the previously shadowed zettel from overlayed box " ,shadowed-box " becomes available.")
    ))
  )
  ,@(if incoming
    `((div (@ (class "zs-warning"))
      (h2 "Warning!")
      (p "If you delete this zettel, incoming references from the following zettel will become invalid.")
      (ul ,@(map wui-item-link incoming))
    ))
  )
  ,@(if (and (bound? 'useless) useless)
    `((div (@ (class "zs-warning"))
      (h2 "Warning!")
      (p "Deleting this zettel will also delete the following files, so that they will not be interpreted as content for this zettel.")
      (ul ,@(map wui-item useless))
    ))
  )
  ,(wui-meta-desc metapairs)
  (form (@ (method "POST")) (input (@ (class "zs-primary") (type "submit") (value "Delete"))))
)

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














=== yuin/goldmark
; URL & Source
: [[https://github.com/yuin/goldmark]]
; License
: MIT License
```

FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
```

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

; URL & Source sx
: [[https://zettelstore.de/sx]]


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

`(article
  (header (h1 ,heading))
  (form (@ (action ,form-action-url) (method "POST") (enctype "multipart/form-data"))
  (div
    (label (@ (for "zs-title")) "Title " (a (@ (title "Main heading of this zettel.")) (@H "ⓘ")))
    (input (@ (class "zs-input") (type "text") (id "zs-title") (name "title") (placeholder "Title..") (value ,meta-title) (autofocus))))
  (div
    (label (@ (for "zs-role")) "Role " (a (@ (title "One word, without spaces, to set the main role of this zettel.")) (@H "ⓘ")))
    (input (@ (class "zs-input") (type "text") (id "zs-role") (name "role") (placeholder "role..") (value ,meta-role)
      ,@(if role-data '((list "zs-role-data")))
    ))

    ,@(wui-datalist "zs-role-data" role-data)



  )
  (div
    (label (@ (for "zs-tags")) "Tags " (a (@ (title "Tags must begin with an '#' sign. They are separated by spaces.")) (@H "ⓘ")))
    (input (@ (class "zs-input") (type "text") (id "zs-tags") (name "tags") (placeholder "#tag") (value ,meta-tags))))
  (div
    (label (@ (for "zs-meta")) "Metadata " (a (@ (title "Other metadata for this zettel. Each line contains a key/value pair, separated by a colon ':'.")) (@H "ⓘ")))
    (textarea (@ (class "zs-input") (id "zs-meta") (name "meta") (rows "4") (placeholder "metakey: metavalue")) ,meta))
  (div
    (label (@ (for "zs-syntax")) "Syntax " (a (@ (title "Syntax of zettel content below, one word. Typically 'zmk' (for zettelmarkup).")) (@H "ⓘ")))
    (input (@ (class "zs-input") (type "text") (id "zs-syntax") (name "syntax") (placeholder "syntax..") (value ,meta-syntax)
      ,@(if syntax-data '((list "zs-syntax-data")))
    ))

    ,@(wui-datalist "zs-syntax-data" syntax-data)



  )
  ,@(if (bound? 'content)
    `((div
      (label (@ (for "zs-content")) "Content " (a (@ (title "Content for this zettel, according to above syntax.")) (@H "ⓘ")))
      (textarea (@ (class "zs-input zs-content") (id "zs-content") (name "content") (rows "20") (placeholder "Zettel content..")) ,content)
    ))
  )

`(article
  (header (h1 "Information for Zettel " ,zid)
    (p
      (a (@ (href ,web-url)) "Web")
      (@H " · ") (a (@ (href ,context-url)) "Context")
      ,@(if (bound? 'edit-url) `((@H " · ") (a (@ (href ,edit-url)) "Edit")))
      ,@(if (bound? 'copy-url) `((@H " · ") (a (@ (href ,copy-url)) "Copy")))
      ,@(if (bound? 'version-url) `((@H " · ") (a (@ (href ,version-url)) "Version")))
      ,@(if (bound? 'child-url) `((@H " · ") (a (@ (href ,child-url)) "Child")))
      ,@(if (bound? 'folge-url) `((@H " · ") (a (@ (href ,folge-url)) "Folge")))
      ,@(if (bound? 'rename-url) `((@H " · ") (a (@ (href ,rename-url)) "Rename")))
      ,@(if (bound? 'delete-url) `((@H " · ") (a (@ (href ,delete-url)) "Delete")))
    )
  )
  (h2 "Interpreted Metadata")
  (table ,@(map wui-table-row metadata))
  (h2 "References")
  ,@(if local-links `((h3 "Local")    (ul ,@(map wui-valid-link local-links))))




  ,@(if query-links `((h3 "Queries")  (ul ,@(map wui-item-link query-links))))




  ,@(if ext-links   `((h3 "External") (ul ,@(map wui-item-popup-link ext-links))))




  (h3 "Unlinked")
  ,@unlinked-content
  (form
    (label (@ (for "phrase")) "Search Phrase")
    (input (@ (class "zs-input") (type "text") (id "phrase") (name ,query-key-phrase) (placeholder "Phrase..") (value ,phrase)))
  )
  (h2 "Parts and encodings")
  ,(wui-enc-matrix enc-eval)
  (h3 "Parsed (not evaluated)")
  ,(wui-enc-matrix enc-parsed)
  ,@(if shadow-links
    `((h2 "Shadowed Boxes")
      (ul ,@(map wui-item shadow-links))
    )
  )
)

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

        `((input (@ (type "hidden") (name ,query-key-query) (value ,query-value)))
          (input (@ (type "hidden") (name ,query-key-seed) (value ,seed)))
          (input (@ (class "zs-primary") (type "submit") (value "Save As Zettel")))
        )
      )
  )
)

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

`(article
  (header (h1 "Rename Zettel " ,zid))
  (p "Do you really want to rename this zettel?")
  ,@(if incoming
    `((div (@ (class "zs-warning"))
      (h2 "Warning!")
      (p "If you rename this zettel, incoming references from the following zettel will become invalid.")
      (ul ,@(map wui-item-link incoming))
    ))
  )
  ,@(if (and (bound? 'useless) useless)
    `((div (@ (class "zs-warning"))
      (h2 "Warning!")
      (p "Renaming this zettel will also delete the following files, so that they will not be interpreted as content for this zettel.")
      (ul ,@(map wui-item useless))
    ))
  )
  (form (@ (method "POST"))
    (input (@ (type "hidden") (id "curzid") (name "curzid") (value ,zid)))
    (div
      (label (@ (for "newzid")) "New zettel id")
      (input (@ (class "zs-input") (type "text") (id "newzid") (name "newzid") (placeholder "ZID..") (value ,zid) (autofocus))))
    (div (input (@ (class "zs-primary") (type "submit") (value "Rename"))))
  )
  ,(wui-meta-desc metapairs)
)

;;;----------------------------------------------------------------------------
;;; Copyright (c) 2023-present Detlef Stern
;;;
;;; This file is part of Zettelstore.
;;;
;;; Zettelstore is licensed under the latest version of the EUPL (European
;;; Union Public License). Please see file LICENSE.txt for your rights and
;;; obligations under this license.
;;;----------------------------------------------------------------------------

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

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

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

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

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

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

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

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

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

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

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

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

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

		return zettel.Zettel{}, err
	}
	zettel := zettel.Zettel{Meta: m, Content: zettel.NewContent(c)}
	dp.log.Trace().Zid(zid).Msg("GetZettel")
	return zettel, nil
}

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





	return dp.dirSrv.GetDirEntry(zid).IsValid()








}

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

		return box.ErrNotFound
	}
	if dp.readonly {
		return box.ErrReadOnly
	}

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

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

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

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

	}

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

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











}

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

		if z, err := p.GetZettel(ctx, zid); err == nil {
			mgr.Enrich(ctx, z.Meta, i+1)
			result = append(result, z)
		}
	}
	return result, nil
}










































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

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

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

	m, err := mgr.idxStore.GetMeta(ctx, zid)
	if err != nil {
		return nil, err
	}
	mgr.Enrich(ctx, m, 0)
	return m, nil
}

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



	compSearch := q.RetrieveAndCompile(ctx, mgr, metaSeq)



	if result := compSearch.Result(); result != nil {
		mgr.mgrLog.Trace().Int("count", int64(len(result))).Msg("found without ApplyMeta")
		return result, nil
	}
	selected := map[id.Zid]*meta.Meta{}
	for _, term := range compSearch.Terms {
		rejected := id.Set{}
		handleMeta := func(m *meta.Meta) {
			zid := m.Zid
			if rejected.Contains(zid) {
				mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/alreadyRejected")
				return

package manager

import (
	"context"
	"strconv"

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

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

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

	if box.DoNotEnrich(ctx) {
		// Enrich is called indirectly via indexer or enrichment is not requested
		// because of other reasons -> ignore this call, do not update metadata
		return
	}
	computePublished(m)
	if boxNumber > 0 {
		m.Set(api.KeyBoxNumber, strconv.Itoa(boxNumber))
	}
	mgr.idxStore.Enrich(ctx, m)
}

func computeCreated(zid id.Zid) string {
	if zid <= 10101000000 {
		// A year 0000 is not allowed and therefore an artificaial Zid.
		// In the year 0001, the month must be > 0.

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

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

func (mgr *Manager) idxCollectFromMeta(ctx context.Context, m *meta.Meta, zi *store.ZettelIndex, cData *collectData) {

			}
		}
	}
}

func (mgr *Manager) idxProcessData(ctx context.Context, zi *store.ZettelIndex, cData *collectData) {
	for ref := range cData.refs {
		if mgr.HasZettel(ctx, ref) {
			zi.AddBackRef(ref)
		} else {
			zi.AddDeadRef(ref)
		}
	}
	zi.SetWords(cData.words)
	zi.SetUrls(cData.urls)
}

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

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

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

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

	"zettelstore.de/client.fossil/maps"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager/memstore"
	"zettelstore.de/z/box/manager/store"
	"zettelstore.de/z/config"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/logger"

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

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

type bidiRefs struct {
	forward  id.Slice
	backward id.Slice
}

type zettelData struct {
	meta      *meta.Meta
	dead      id.Slice
	forward   id.Slice
	backward  id.Slice
	otherRefs map[string]bidiRefs
	words     []string
	urls      []string







}

type stringRefs map[string]id.Slice

type memStore struct {
	mx     sync.RWMutex
	intern map[string]string // map to intern strings
	idx    map[id.Zid]*zettelData
	dead   map[id.Zid]id.Slice // map dead refs where they occur
	words  stringRefs
	urls   stringRefs

	// Stats
	mxStats sync.Mutex
	updates uint64
}

// New returns a new memory-based index store.
func New() store.Store {
	return &memStore{
		intern: make(map[string]string, 1024),
		idx:    make(map[id.Zid]*zettelData),
		dead:   make(map[id.Zid]id.Slice),
		words:  make(stringRefs),
		urls:   make(stringRefs),
	}
}

func (ms *memStore) GetMeta(_ context.Context, zid id.Zid) (*meta.Meta, error) {
	ms.mx.RLock()
	defer ms.mx.RUnlock()
	if zi, found := ms.idx[zid]; found {
		return zi.meta.Clone(), nil
	}
	return nil, box.ErrNotFound
}

func (ms *memStore) Enrich(_ context.Context, m *meta.Meta) {
	if ms.doEnrich(m) {
		ms.mxStats.Lock()
		ms.updates++
		ms.mxStats.Unlock()
	}
}

func (ms *memStore) doEnrich(m *meta.Meta) bool {
	ms.mx.RLock()
	defer ms.mx.RUnlock()
	zi, ok := ms.idx[m.Zid]

		updated = true
	}
	if len(zi.forward) > 0 {
		m.Set(api.KeyForward, zi.forward.String())
		back = remRefs(back, zi.forward)
		updated = true
	}
	for k, refs := range zi.otherRefs {
		if len(refs.backward) > 0 {
			m.Set(k, refs.backward.String())
			back = remRefs(back, refs.backward)
			updated = true
		}
	}
	if len(back) > 0 {

			continue
		}
		result.AddSlice(refs)
	}
	return result
}

func addBackwardZids(result id.Set, zid id.Zid, zi *zettelData) {
	// Must only be called if ms.mx is read-locked!
	result.Zid(zid)
	result.AddSlice(zi.backward)
	for _, mref := range zi.otherRefs {
		result.AddSlice(mref.backward)
	}
}

func removeOtherMetaRefs(m *meta.Meta, back id.Slice) id.Slice {
	for _, p := range m.PairsRest() {
		switch meta.Type(p.Key) {

			}
		}
	}
	return back
}

func (ms *memStore) UpdateReferences(_ context.Context, zidx *store.ZettelIndex) id.Set {
	m := ms.makeMeta(zidx)
	ms.mx.Lock()
	defer ms.mx.Unlock()
	zi, ziExist := ms.idx[zidx.Zid]
	if !ziExist || zi == nil {
		zi = &zettelData{}
		ziExist = false
	}

	// Is this zettel an old dead reference mentioned in other zettel?
	var toCheck id.Set
	if refs, ok := ms.dead[zidx.Zid]; ok {
		// These must be checked later again
		toCheck = id.NewSet(refs...)
		delete(ms.dead, zidx.Zid)
	}

	zi.meta = m
	ms.updateDeadReferences(zidx, zi)
	ms.updateForwardBackwardReferences(zidx, zi)
	ms.updateMetadataReferences(zidx, zi)
	zi.words = updateWordSet(zidx.Zid, ms.words, zi.words, zidx.GetWords())
	zi.urls = updateWordSet(zidx.Zid, ms.urls, zi.urls, zidx.GetUrls())

	// Check if zi must be inserted into ms.idx
	if !ziExist {
		ms.idx[zidx.Zid] = zi
	}

	return toCheck
}

var internableKeys = map[string]bool{
	api.KeyRole:      true,
	api.KeySyntax:    true,
	api.KeyFolgeRole: true,
	api.KeyLang:      true,
	api.KeyReadOnly:  true,
}

func isInternableValue(key string) bool {
	if internableKeys[key] {
		return true
	}
	return strings.HasSuffix(key, "-role")
}

func (ms *memStore) internString(s string) string {
	if is, found := ms.intern[s]; found {
		return is
	}
	ms.intern[s] = s
	return s
}

func (ms *memStore) makeMeta(zidx *store.ZettelIndex) *meta.Meta {
	origM := zidx.GetMeta()
	copyM := meta.New(origM.Zid)
	for _, p := range origM.Pairs() {
		key := ms.internString(p.Key)
		if isInternableValue(key) {
			copyM.Set(key, ms.internString(p.Value))
		} else if key == api.KeyBoxNumber || !meta.IsComputed(key) {
			copyM.Set(key, p.Value)
		}
	}
	return copyM
}

func (ms *memStore) updateDeadReferences(zidx *store.ZettelIndex, zi *zettelData) {
	// Must only be called if ms.mx is write-locked!
	drefs := zidx.GetDeadRefs()
	newRefs, remRefs := refsDiff(drefs, zi.dead)
	zi.dead = drefs
	for _, ref := range remRefs {
		ms.dead[ref] = remRef(ms.dead[ref], zidx.Zid)
	}
	for _, ref := range newRefs {
		ms.dead[ref] = addRef(ms.dead[ref], zidx.Zid)
	}
}

func (ms *memStore) updateForwardBackwardReferences(zidx *store.ZettelIndex, zi *zettelData) {
	// Must only be called if ms.mx is write-locked!
	brefs := zidx.GetBackRefs()
	newRefs, remRefs := refsDiff(brefs, zi.forward)
	zi.forward = brefs
	for _, ref := range remRefs {
		bzi := ms.getEntry(ref)
		bzi.backward = remRef(bzi.backward, zidx.Zid)
	}
	for _, ref := range newRefs {
		bzi := ms.getEntry(ref)
		bzi.backward = addRef(bzi.backward, zidx.Zid)
	}
}

func (ms *memStore) updateMetadataReferences(zidx *store.ZettelIndex, zi *zettelData) {
	// Must only be called if ms.mx is write-locked!
	inverseRefs := zidx.GetInverseRefs()
	for key, mr := range zi.otherRefs {
		if _, ok := inverseRefs[key]; ok {
			continue
		}
		ms.removeInverseMeta(zidx.Zid, key, mr.forward)
	}
	if zi.otherRefs == nil {
		zi.otherRefs = make(map[string]bidiRefs)
	}
	for key, mrefs := range inverseRefs {
		mr := zi.otherRefs[key]
		newRefs, remRefs := refsDiff(mrefs, mr.forward)
		mr.forward = mrefs
		zi.otherRefs[key] = mr

		for _, ref := range newRefs {
			bzi := ms.getEntry(ref)
			if bzi.otherRefs == nil {
				bzi.otherRefs = make(map[string]bidiRefs)
			}
			bmr := bzi.otherRefs[key]
			bmr.backward = addRef(bmr.backward, zidx.Zid)
			bzi.otherRefs[key] = bmr
		}
		ms.removeInverseMeta(zidx.Zid, key, remRefs)
	}
}

func updateWordSet(zid id.Zid, srefs stringRefs, prev []string, next store.WordSet) []string {

	newWords, removeWords := next.Diff(prev)
	for _, word := range newWords {
		if refs, ok := srefs[word]; ok {
			srefs[word] = addRef(refs, zid)
			continue
		}
		srefs[word] = id.Slice{zid}

			continue
		}
		srefs[word] = refs2
	}
	return next.Words()
}

func (ms *memStore) getEntry(zid id.Zid) *zettelData {
	// Must only be called if ms.mx is write-locked!
	if zi, ok := ms.idx[zid]; ok {
		return zi
	}
	zi := &zettelData{}
	ms.idx[zid] = zi
	return zi
}

func (ms *memStore) DeleteZettel(_ context.Context, zid id.Zid) id.Set {
	ms.mx.Lock()
	defer ms.mx.Unlock()

	zi, ok := ms.idx[zid]
	if !ok {
		return nil
	}

	ms.deleteDeadSources(zid, zi)
	toCheck := ms.deleteForwardBackward(zid, zi)
	if len(zi.otherRefs) > 0 {
		for key, mrefs := range zi.otherRefs {
			ms.removeInverseMeta(zid, key, mrefs.forward)
		}
	}
	ms.deleteWords(zid, zi.words)
	delete(ms.idx, zid)
	return toCheck
}

func (ms *memStore) deleteDeadSources(zid id.Zid, zi *zettelData) {
	// Must only be called if ms.mx is write-locked!
	for _, ref := range zi.dead {
		if drefs, ok := ms.dead[ref]; ok {
			drefs = remRef(drefs, zid)
			if len(drefs) > 0 {
				ms.dead[ref] = drefs
			} else {
				delete(ms.dead, ref)
			}
		}
	}
}

func (ms *memStore) deleteForwardBackward(zid id.Zid, zi *zettelData) id.Set {
	// Must only be called if ms.mx is write-locked!
	var toCheck id.Set
	for _, ref := range zi.forward {
		if fzi, ok := ms.idx[ref]; ok {
			fzi.backward = remRef(fzi.backward, zid)
		}
	}

	return toCheck
}

func (ms *memStore) removeInverseMeta(zid id.Zid, key string, forward id.Slice) {
	// Must only be called if ms.mx is write-locked!
	for _, ref := range forward {
		bzi, ok := ms.idx[ref]
		if !ok || bzi.otherRefs == nil {
			continue
		}
		bmr, ok := bzi.otherRefs[key]
		if !ok {
			continue
		}
		bmr.backward = remRef(bmr.backward, zid)
		if len(bmr.backward) > 0 || len(bmr.forward) > 0 {
			bzi.otherRefs[key] = bmr
		} else {
			delete(bzi.otherRefs, key)
			if len(bzi.otherRefs) == 0 {
				bzi.otherRefs = nil
			}
		}
	}
}

func (ms *memStore) deleteWords(zid id.Zid, words []string) {
	// Must only be called if ms.mx is write-locked!

		ms.words[word] = refs2
	}
}

func (ms *memStore) ReadStats(st *store.Stats) {
	ms.mx.RLock()
	st.Zettel = len(ms.idx)

	st.Words = uint64(len(ms.words))
	st.Urls = uint64(len(ms.urls))
	ms.mx.RUnlock()
	ms.mxStats.Lock()
	st.Updates = ms.updates
	ms.mxStats.Unlock()
}

func (ms *memStore) Dump(w io.Writer) {
	ms.mx.RLock()
	defer ms.mx.RUnlock()

	io.WriteString(w, "=== Dump\n")

		fmt.Fprintln(w, "=====", id)
		zi := ms.idx[id]
		if len(zi.dead) > 0 {
			fmt.Fprintln(w, "* Dead:", zi.dead)
		}
		dumpZids(w, "* Forward:", zi.forward)
		dumpZids(w, "* Backward:", zi.backward)
		for k, fb := range zi.otherRefs {
			fmt.Fprintln(w, "* Meta", k)
			dumpZids(w, "** Forward:", fb.forward)
			dumpZids(w, "** Backward:", fb.backward)
		}
		dumpStrings(w, "* Words", "", "", zi.words)
		dumpStrings(w, "* URLs", "[[", "]]", zi.urls)
	}

}

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

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

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

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

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

package store

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

// ZettelIndex contains all index data of a zettel.
type ZettelIndex struct {
	Zid         id.Zid            // zid of the indexed zettel
	meta        *meta.Meta        // full metadata
	backrefs    id.Set            // set of back references
	inverseRefs map[string]id.Set // references of inverse keys
	deadrefs    id.Set            // set of dead references
	words       WordSet
	urls        WordSet
}

// NewZettelIndex creates a new zettel index.
func NewZettelIndex(m *meta.Meta) *ZettelIndex {
	return &ZettelIndex{
		Zid:         m.Zid,
		meta:        m,
		backrefs:    id.NewSet(),
		inverseRefs: make(map[string]id.Set),
		deadrefs:    id.NewSet(),
	}
}

// AddBackRef adds a reference to a zettel where the current zettel links to
// without any more information.
func (zi *ZettelIndex) AddBackRef(zid id.Zid) {
	zi.backrefs.Zid(zid)
}

// AddInverseRef adds a named reference to a zettel. On that zettel, the given
// metadata key should point back to the current zettel.
func (zi *ZettelIndex) AddInverseRef(key string, zid id.Zid) {
	if zids, ok := zi.inverseRefs[key]; ok {
		zids.Zid(zid)
		return
	}
	zi.inverseRefs[key] = id.NewSet(zid)
}

// AddDeadRef adds a dead reference to a zettel.
func (zi *ZettelIndex) AddDeadRef(zid id.Zid) {
	zi.deadrefs.Zid(zid)
}

// SetWords sets the words to the given value.
func (zi *ZettelIndex) SetWords(words WordSet) { zi.words = words }

// SetUrls sets the words to the given value.
func (zi *ZettelIndex) SetUrls(urls WordSet) { zi.urls = urls }

// GetDeadRefs returns all dead references as a sorted list.
func (zi *ZettelIndex) GetDeadRefs() id.Slice { return zi.deadrefs.Sorted() }


// GetMeta return just the raw metadata.
func (zi *ZettelIndex) GetMeta() *meta.Meta { return zi.meta }

// GetBackRefs returns all back references as a sorted list.
func (zi *ZettelIndex) GetBackRefs() id.Slice { return zi.backrefs.Sorted() }



// GetInverseRefs returns all inverse meta references as a map of strings to a sorted list of references
func (zi *ZettelIndex) GetInverseRefs() map[string]id.Slice {
	if len(zi.inverseRefs) == 0 {
		return nil
	}
	result := make(map[string]id.Slice, len(zi.inverseRefs))
	for key, refs := range zi.inverseRefs {
		result[key] = refs.Sorted()
	}
	return result
}

// GetWords returns a reference to the set of words. It must not be modified.
func (zi *ZettelIndex) GetWords() WordSet { return zi.words }

// GetUrls returns a reference to the set of URLs. It must not be modified.
func (zi *ZettelIndex) GetUrls() WordSet { return zi.urls }

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

)

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

		return zettel.Zettel{}, box.ErrNotFound
	}
	z.Meta = z.Meta.Clone()
	mb.log.Trace().Msg("GetZettel")
	return z, nil
}

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

	return found



}

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

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

package notify

import (
	"path/filepath"

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

const (

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

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

import (
	"flag"
	"fmt"
	"os"

	"golang.org/x/term"

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

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

func cmdPassword(fs *flag.FlagSet) (int, error) {

	protectedBoxManager, authPolicy := authManager.BoxWithPolicy(boxManager, rtConfig)
	kern := kernel.Main
	webLog := kern.GetLogger(kernel.WebService)

	var getUser getUserImpl
	logAuth := kern.GetLogger(kernel.AuthService)
	logUc := kern.GetLogger(kernel.CoreService).WithUser(&getUser)
	ucGetUser := usecase.NewGetUser(authManager, boxManager)
	ucAuthenticate := usecase.NewAuthenticate(logAuth, authManager, &ucGetUser)
	ucIsAuth := usecase.NewIsAuthenticated(logUc, &getUser, authManager)
	ucCreateZettel := usecase.NewCreateZettel(logUc, rtConfig, protectedBoxManager)
	ucGetAllZettel := usecase.NewGetAllZettel(protectedBoxManager)

	ucGetZettel := usecase.NewGetZettel(protectedBoxManager)
	ucParseZettel := usecase.NewParseZettel(rtConfig, ucGetZettel)
	ucQuery := usecase.NewQuery(protectedBoxManager)
	ucEvaluate := usecase.NewEvaluate(rtConfig, &ucGetZettel, &ucQuery)
	ucQuery.SetEvaluate(&ucEvaluate)
	ucListSyntax := usecase.NewListSyntax(protectedBoxManager)
	ucListRoles := usecase.NewListRoles(protectedBoxManager)
	ucDelete := usecase.NewDeleteZettel(logUc, protectedBoxManager)
	ucUpdate := usecase.NewUpdateZettel(logUc, protectedBoxManager)
	ucRename := usecase.NewRenameZettel(logUc, protectedBoxManager)

	ucRefresh := usecase.NewRefresh(logUc, protectedBoxManager)
	ucVersion := usecase.NewVersion(kernel.Main.GetConfig(kernel.CoreService, kernel.CoreVersion).(string))

	a := api.New(
		webLog.Clone().Str("adapter", "api").Child(),
		webSrv, authManager, authManager, rtConfig, authPolicy)
	wui := webui.New(
		webLog.Clone().Str("adapter", "wui").Child(),
		webSrv, authManager, rtConfig, authManager, boxManager, authPolicy, &ucEvaluate)

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

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

	// API
	webSrv.AddListRoute('a', server.MethodPost, a.MakePostLoginHandler(&ucAuthenticate))
	webSrv.AddListRoute('a', server.MethodPut, a.MakeRenewAuthHandler())



	webSrv.AddListRoute('x', server.MethodGet, a.MakeGetDataHandler(ucVersion))
	webSrv.AddListRoute('x', server.MethodPost, a.MakePostCommandHandler(&ucIsAuth, &ucRefresh))
	webSrv.AddListRoute('z', server.MethodGet, a.MakeQueryHandler(&ucQuery))
	webSrv.AddZettelRoute('z', server.MethodGet, a.MakeGetZettelHandler(ucGetZettel, ucParseZettel, ucEvaluate))
	if !authManager.IsReadonly() {
		webSrv.AddListRoute('z', server.MethodPost, a.MakePostCreateZettelHandler(&ucCreateZettel))
		webSrv.AddZettelRoute('z', server.MethodPut, a.MakeUpdateZettelHandler(&ucUpdate))
		webSrv.AddZettelRoute('z', server.MethodDelete, a.MakeDeleteZettelHandler(&ucDelete))
		webSrv.AddZettelRoute('z', server.MethodMove, a.MakeRenameZettelHandler(&ucRename))
	}

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

package cmd

import (
	"flag"

	"zettelstore.de/client.fossil/maps"
	"zettelstore.de/z/logger"
)

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

	"net/url"
	"os"
	"runtime/debug"
	"strconv"
	"strings"
	"time"

	"zettelstore.de/client.fossil/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/input"

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

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

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

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

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

func getConfig(fs *flag.FlagSet) (string, *meta.Meta) {
	filename, cfg := fetchStartupConfiguration(fs)
	fs.Visit(func(flg *flag.Flag) {
		switch flg.Name {
		case "p":
			cfg.Set(keyListenAddr, net.JoinHostPort("127.0.0.1", flg.Value.String()))
		case "a":
			cfg.Set(keyAdminPort, flg.Value.String())
		case "d":

			cfg.Set(keyDebug, flg.Value.String())
		case "r":
			cfg.Set(keyReadOnly, flg.Value.String())
		case "v":
			cfg.Set(keyVerbose, flg.Value.String())
		}
	})
	return filename, cfg
}

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

		return 1
	}
	fs := command.GetFlags()
	if err := fs.Parse(args); err != nil {
		fmt.Fprintf(os.Stderr, "%s: unable to parse flags: %v %v\n", name, args, err)
		return 1
	}
	filename, cfg := getConfig(fs)
	if !setServiceConfig(cfg) {
		fs.Usage()
		return 2
	}

	kern := kernel.Main
	var createManager kernel.CreateBoxManagerFunc

			return nil
		},
	)

	if command.Simple {
		kern.SetConfig(kernel.ConfigService, kernel.ConfigSimpleMode, "true")
	}
	kern.Start(command.Header, command.LineServer, filename)
	exitCode, err := command.Func(fs)
	if err != nil {
		fmt.Fprintf(os.Stderr, "%s: %v\n", name, err)
	}
	kern.Shutdown(true)
	return exitCode
}

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

id: 00001002000000
title: Design goals for the Zettelstore
role: manual
tags: #design #goal #manual #zettelstore
syntax: zmk
created: 20210126175322
modified: 20230624171152

Zettelstore supports the following design goals:

; Longevity of stored notes / zettel
: Every zettel you create should be readable without the help of any tool, even without Zettelstore.
: It should be not hard to write other software that works with your zettel.
: Normal zettel should be stored in a single file.
  If this is not possible: at most in two files: one for the metadata, one for the content.
  The only exception are [[predefined zettel|00001005090000]] stored in the Zettelstore executable.
: There is no additional database.
; Single user
: All zettel belong to you, only to you.
  Zettelstore provides its services only to one person: you.
  If the computer running Zettelstore is securely configured, there should be no risk that others are able to read or update your zettel.
: If you want, you can customize Zettelstore in a way that some specific or all persons are able to read some of your zettel.
; Ease of installation
: If you want to use the Zettelstore software, all you need is to copy the executable to an appropriate file directory and start working.

; Simple service
: The purpose of Zettelstore is to safely store your zettel and to provide some initial relations between them.
: External software can be written to deeply analyze your zettel and the structures they form.
; Security by default
: Without any customization, Zettelstore provides its services in a safe and secure manner and does not expose you (or other users) to security risks.
: If you know what use are doing, Zettelstore allows you to relax some security-related preferences.
  However, even in this case, the more secure way is chosen.
: The Zettelstore software uses a minimal design and uses other software dependencies only is essential needed.
: There will be no plugin mechanism, which allows external software to control the inner workings of the Zettelstore software.

id: 00001005090000
title: List of predefined zettel
role: manual
tags: #manual #reference #zettelstore
syntax: zmk
created: 20210126175322
modified: 20230619133707

The following table lists all predefined zettel with their purpose.

|= Identifier :|= Title | Purpose
| [[00000000000001]] | Zettelstore Version | Contains the version string of the running Zettelstore
| [[00000000000002]] | Zettelstore Host | Contains the name of the computer running the Zettelstore
| [[00000000000003]] | Zettelstore Operating System | Contains the operating system and CPU architecture of the computer running the Zettelstore

| [[00000000010200]] | Zettelstore Login Form HTML Template | Layout of the login form, when authentication is [[enabled|00001010040100]]
| [[00000000010300]] | Zettelstore List Zettel HTML Template | Used when displaying a list of zettel
| [[00000000010401]] | Zettelstore Detail HTML Template | Layout for the HTML detail view of one zettel
| [[00000000010402]] | Zettelstore Info HTML Template | Layout for the information view of a specific zettel
| [[00000000010403]] | Zettelstore Form HTML Template | Form that is used to create a new or to change an existing zettel that contains text
| [[00000000010404]] | Zettelstore Rename Form HTML Template | View that is displayed to change the [[zettel identifier|00001006050000]]
| [[00000000010405]] | Zettelstore Delete HTML Template | View to confirm the deletion of a zettel
| [[00000000010700]] | Zettelstore Error HTML Template | View to show an error message
| [[00000000019100]] | Zettelstore Sxn Code for Templates | Some helper functions to build the templates
| [[00000000020001]] | Zettelstore Base CSS | System-defined CSS file that is included by the [[Base HTML Template|00000000010100]]
| [[00000000025001]] | Zettelstore User CSS | User-defined CSS file that is included by the [[Base HTML Template|00000000010100]]
| [[00000000029000]] | Zettelstore Role to CSS Map | [[Maps|00001017000000#role-css]] [[role|00001006020000#role]] to a zettel identifier that is included by the [[Base HTML Template|00000000010100]] as an CSS file 
| [[00000000040001]] | Generic Emoji | Image that is shown if [[original image reference|00001007040322]] is invalid
| [[00000000090000]] | New Menu | Contains items that should contain in the zettel template menu
| [[00000000090001]] | New Zettel | Template for a new zettel with role ""[[zettel|00001006020100]]""
| [[00000000090002]] | New User | Template for a new [[user zettel|00001010040200]]
| [[00010000000000]] | Home | Default home zettel, contains some welcome information

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

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

id: 00001006020000
title: Supported Metadata Keys
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210126175322
modified: 20230704161159

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]].

; [!author|''author'']

  When a zettel is expires, Zettelstore does nothing.
  It is up to you to define required actions.
  ''expire'' is just a documentation.
  You could define a query and execute it regularly, for example [[query:expire? ORDER expire]].
  Alternatively, a Zettelstore client software could define some actions when it detects expired zettel.
; [!folge|''folge'']
: Is a property that contains identifier of all zettel that reference this zettel through the [[''precursor''|#precursor]] value.
; [!folge-role|''folge-role'']
: Specifies a suggested [[''role''|#role]] the zettel should use in the future, if zettel currently has a preliminary role.
; [!forward|''forward'']
: Property that contains all references that identify another zettel within the content of the zettel.
; [!id|''id'']
: Contains the [[zettel identifier|00001006050000]], as given by the Zettelstore.
  It cannot be set manually, because it is a computed value.
; [!lang|''lang'']
: Language for the zettel.

id: 00001006030000
title: Supported Key Types
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210126175322
modified: 20230612183742

All [[supported metadata keys|00001006020000]] conform to a type.

User-defined metadata keys conform also to a type, based on the suffix of the key.

|=Suffix|Type
| ''-date'' | [[Timestamp|00001006034500]]

| ''-zid''  | [[Identifier|00001006032000]]
| ''-zids''  | [[IdentifierSet|00001006032500]]
| any other suffix | [[EString|00001006031500]]

The name of the metadata key is bound to the key type

Every key type has an associated validation rule to check values of the given type.
There is also a rule how values are matched, e.g. against a [[search value|00001007706000]] when selecting some zettel.
And there is a rule how values compare for sorting.

* [[Credential|00001006031000]]
* [[EString|00001006031500]]
* [[Identifier|00001006032000]]
* [[IdentifierSet|00001006032500]]
* [[Number|00001006033000]]

id: 00001006032000
title: Identifier Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20230612183459

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

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

=== Query comparison
[[Search values|00001007706000]] with more than 14 characters are truncated to contain exactly 14 characters.

When the [[search operators|00001007705000]] ""less"", ""not less"", ""greater"", and ""not greater"" are given, the length of the search value is checked.
If it contains less than 14 digits, zero digits (""0"") are appended, until it contains exactly 14 digits.

All other comparisons assume that up to 14 characters are given.

Comparison is done through the string representation.

In case of the search operators ""less"", ""not less"", ""greater"", and ""not greater"", this is the same as a numerical comparison.

For example, ""000010"" matches ""[[00001006032000]]"".

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

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

id: 00001006033000
title: Number Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20230612183900

Values of this type denote a numeric integer value.

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

=== Query comparison
[[Search operators|00001007705000]] for equality (""equal"" or ""not equal"", ""has"" or ""not has""), for lesser values (""less"" or ""not less""), or for greater values (""greater"" or ""not greater"") are executed by converting both the [[search value|00001007706000]] and the metadata value into integer values and then comparing them numerically.
Integer values must be in the range -9223372036854775808 … 9223372036854775807.
Comparisons with metadata values outside this range always returns a negative match.
Comparisons with search values outside this range will be executed as a comparison of the string representation values.

All other comparisons (""match"", ""not match"", ""prefix"", ""not prefix"", ""suffix"", and ""not suffix"") are done on the given string representation of the number.
In this case, the number ""+12"" will be treated as different to the number ""12"".

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

id: 00001006034500
title: Timestamp Key Type
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210212135017
modified: 20230612183509

Values of this type denote a point in time.

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

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

=== Query comparison
[[Search values|00001007706000]] with more than 14 characters are truncated to contain exactly 14 characters.

When the [[search operators|00001007705000]] ""less"", ""not less"", ""greater"", and ""not greater"" are given, the length of the search value is checked.
If it contains less than 14 digits, zero digits (""0"") are appended, until it contains exactly 14 digits.

All other comparisons assume that up to 14 characters are given.

Comparison is done through the string representation.
In case of the search operators ""less"", ""not less"", ""greater"", and ""not greater"", this is the same as a numerical comparison.

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

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

id: 00001007700000
title: Query Expression
role: manual
tags: #manual #search #zettelstore
syntax: zmk
created: 20220805150154
modified: 20230731161954

A query expression allows you to search for specific zettel and to perform some actions on them.
You may select zettel based on a list of [[zettel identifier|00001006050000]], based on a query directive, based on a full-text search, based on specific metadata values, or some or all of them.

A query expression consists of an optional __[[zettel identifier list|00001007710000]]__, zero or more __[[query directives|00001007720000]]__, an optional __[[search expression|00001007701000]]__, and an optional __[[action list|00001007770000]]__.
The latter two are separated by a vertical bar character (""''|''"", U+007C).

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


* [[List of zettel identifier|00001007710000]]

* [[Query directives|00001007720000]]





** [[Context directive|00001007720300]]

** [[Ident directive|00001007720600]]







** [[Items directive|00001007720900]]


** [[Unlinked directive|00001007721200]]
* [[Search expression|00001007701000]]













** [[Search term|00001007702000]]
** [[Search operator|00001007705000]]
** [[Search value|00001007706000]]
* [[Action list|00001007770000]]

Here are [[some examples|00001007790000]], which can be used to manage a Zettelstore:
{{{00001007790000}}}

id: 00001007701000
title: Query: Search Expression
role: manual
tags: #manual #search #zettelstore
syntax: zmk
created: 20230707205043
modified: 20230707210039

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

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

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

Above sequence of search expressions may be combined by specifying the keyword ''OR''.
At most one of those sequences must be true so that a zettel is selected.

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

id: 00001007702000
title: Search term
role: manual
tags: #manual #search #zettelstore
syntax: zmk
created: 20220805150154
modified: 20230612180954

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

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

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

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

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

  However, the operators ""less"" and ""greater"" are not supported, they are internally translated into the ""match"" operators.
  Similar, ""not less"" and ""not greater"" are translated into ""not match"".
  It simply does not make sense to search the content of all zettel for words less than a specific word, for example.

  **Note:** the search value will be normalized according to Unicode NKFD, ignoring everything except letters and numbers.
  Therefore, the following search expression are essentially the same: ''"search syntax"'' and ''search syntax''.
  The first is a search expression with one search value, which is normalized to two strings to be searched for.
  The second is a search expression containing two search values, giving two string to be searched for.
* A metadata key followed by ""''?''"" or ""''!?''"".

  Is true, if zettel metadata contains / does not contain the given key.

id: 00001007705000
title: Search operator
role: manual
tags: #manual #search #zettelstore
syntax: zmk
created: 20220805150154
modified: 20230612180539

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

The following are allowed search operator characters:
* The exclamation mark character (""''!''"", U+0021) negates the meaning.
* The equal sign character (""''=''"", U+003D) compares on equal content (""equals operator"").
* The tilde character (""''~''"", U+007E) compares on matching (""match operator"").
* The left square bracket character (""''[''"", U+005B) matches if there is some prefix (""prefix operator"").
* The right square bracket character (""'']''"", U+005D) compares a suffix relationship (""suffix operator"").
* The colon character (""'':''"", U+003A) compares depending on the on the actual [[key type|00001006030000]] (""has operator"").
  In most cases, it acts as a equals operator, but for some type it acts as the match operator.
* The less-than sign character (""''<''"", U+003C) matches if the search value is somehow less then the metadata value (""less operator"").
* The greater-than sign character (""''>''"", U+003E) matches if the search value is somehow greater then the metadata value (""greater operator"").
* The question mark (""''?''"", U+003F) checks for an existing metadata key (""exist operator"").
  In this case no [[search value|00001007706000]] must be given.

Since the exclamation mark character can be combined with the other, there are 18 possible combinations:
# ""''!''"": is an abbreviation of the ""''!~''"" operator.
# ""''~''"": is successful if the search value matched the value to be compared.
# ""''!~''"": is successful if the search value does not match the value to be compared.
# ""''=''"": is successful if the search value is equal to one word of the value to be compared.
# ""''!=''"": is successful if the search value is not equal to any word of the value to be compared.
# ""''[''"": is successful if the search value is a prefix of the value to be compared.
# ""''![''"": is successful if the search value is not a prefix of the value to be compared.
# ""'']''"": is successful if the search value is a suffix of the value to be compared.
# ""''!]''"": is successful if the search value is not a suffix of the value to be compared.
# ""'':''"": is successful if the search value is has/match one word of the value to be compared.
# ""''!:''"": is successful if the search value is not match/has to any word of the value to be compared.
# ""''<''"": is successful if the search value is less than the value to be compared.
# ""''!<''"": is successful if the search value is not less than, e.g. greater or equal than the value to be compared.
# ""''>''"": is successful if the search value is greater than the value to be compared.
# ""''!>''"": is successful if the search value is not greater than, e.g. less or equal than the value to be compared.
# ""''?''"": is successful if the metadata contains the given key.
# ""''!?''"": is successful if the metadata does not contain the given key.
# ""''''"": a missing search operator can only occur for a full-text search.
  It is equal to the ""''~''"" operator.

id: 20230707202600
title: Query: List of Zettel Identifier
role: manual
tags: #manual #search #zettelstore
syntax: zmk
created: 20230707202652

A query may start with a list of [[zettel identifier|00001006050000]], where the identifier are separated by one ore more space characters.

If you specify at least one query directive, this list acts as a input for the first query directive.
Otherwise, only the zettel of the given list are used to evaluated the search expression or the action list (if no search expression was given).

Some examples:
* [[query:00001007700000 CONTEXT]] returns the context of this zettel.
* [[query:00001007700000 00001007031140 man]] searches the given two zettel for a string ""man"".
* [[query:00001007700000 00001007031140 | tags]] return a tag cloud with tags from those two zettel.
* [[query:00001007700000 00001007031140]] returns a list with the two zettel.

id: 00001007720000
title: Query Directives
role: manual
tags: #manual #search #zettelstore
syntax: zmk
created: 20230707203135
modified: 20230731162002

A query directive transforms a list of zettel identifier into a list of zettel identifiert.
It is only valid if a list of zettel identifier is specified at the beginning of the query expression.
Otherwise the text of the directive is interpreted as a search expression.
For example, ''CONTEXT'' is interpreted as a full-text search for the word ""context"".

Every query directive therefore consumes a list of zettel, and it produces a list of zettel according to the specific directive.

* [[Context directive|00001007720300]]
* [[Ident directive|00001007720600]]
* [[Items directive|00001007720900]]
* [[Unlinked directive|00001007721200]]

id: 00001007720300
title: Query: Context Directive
role: manual
tags: #manual #search #zettelstore
syntax: zmk
created: 20230707204706
modified: 20230724153832

A context directive calculates the __context__ of a list of zettel identifier.
It starts with the keyword ''CONTEXT''.

Optionally you may specify some context details, after the keyword ''CONTEXT'', separated by space characters.
These are:
* ''BACKWARD'': search for context only though backward links,
* ''FORWARD'': search for context only through forward links,
* ''COST'', one or more space characters, and a positive integer: set the maximum __cost__ (default: 17),
* ''MAX'', one or more space characters, and a positive integer: set the maximum number of context zettel (default: 200).

If no ''BACKWARD'' and ''FORWARD'' is specified, a search for context zettel will be done though backward and forward links.

The cost of a context zettel is calculated iteratively:
* Each of the specified zettel hast a cost of one.
* A zettel found as a single folge zettel or single precursor zettel has the cost of the originating zettel, plus one.
* A zettel found as a single successor zettel or single predecessor zettel has the cost of the originating zettel, plus two.
* A zettel found via another link without being part of a [[set of zettel identifier|00001006032500]], has the cost of the originating zettel, plus three.
* A zettel which is part of a set of zettel identifier, has the cost of the originating zettel, plus one of the three choices above and multiplied with roughly a logarithmic value based on the size of the set.
* A zettel with the same tag, has the cost of the originating zettel, plus the number of zettel with the same tag (if it is less than eight), or the cost of the originating zettel plus two, multiplied by number of zettel with the same tag divided by four.

The maximum cost is only checked for all zettel that are not directly reachable from the initial, specified list of zettel.
This ensures that initial zettel that have only a highly used tag, will also produce some context zettel.

Despite its possibly complicated structure, this algorithm ensures in practice that the zettel context is a list of zettel, where the first elements are ""near"" to the specified zettel and the last elements are more ""distant"" to the specified zettel.
It also penalties zettel that acts as a ""hub"" to other zettel, to make it more likely that only relevant zettel appear on the context list.

This directive may be specified only once as a query directive.
A second occurence of ''CONTEXT'' is interpreted as a [[search expression|00001007701000]].
In most cases it is easier to adjust the maximum cost than to perform another context search, which is relatively expensive in terms of retrieving power.

id: 00001007720600
title: Query: Ident Directive
role: manual
tags: #manual #search #zettelstore
syntax: zmk
created: 20230724153018
modified: 20230724154015

An ident directive is needed if you want to specify just a list of zettel identifier.
It starts with / consists of the keyword ''IDENT''.

When not using the ident directive, zettel identifier are interpreted as a [[search expression|00001007701000]].

id: 00001007720900
title: Query: Items Directive
role: manual
tags: #manual #search #zettelstore
syntax: zmk
created: 00010101000000
modified: 20230729120755

The items directive works on zettel that act as a ""table of contents"" for other zettel.
The [[initial zettel|00001000000000]] of this manual is one example, the [[general API description|00001012000000]] is another.
Every zettel with a certain internal structure can act as the ""table of contents"" for others.

What is a ""table of contents""?
Basically, it is just a list of references to other zettel.

To retrieve the items of a zettel, the software looks at first level [[list items|00001007030200]].
If an item contains a valid reference to a zettel, this reference will be interpreted as an item in the items list, in the ""table of contents"".

This applies only to first level list items (ordered or unordered list), but not to deeper levels.
Only the first reference to a valid zettel is collected for the table of contents.
Following references to zettel within such an list item are ignored.


````
# curl 'http://127.0.0.1:23123/z?q=00001000000000+ITEMS'
00001001000000 Introduction to the Zettelstore
00001002000000 Design goals for the Zettelstore
00001003000000 Installation of the Zettelstore software
00001004000000 Configuration of Zettelstore
00001005000000 Structure of Zettelstore
00001006000000 Layout of a Zettel
00001007000000 Zettelmarkup
00001008000000 Other Markup Languages
00001010000000 Security
00001012000000 API
00001014000000 Web user interface
00001017000000 Tips and Tricks
00001018000000 Troubleshooting
````

id: 00001007721200
title: Query: Unlinked Directive
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20211119133357
modified: 20230731163343

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

__Unlinked references__ are phrases in a zettel that mention the title of another, currently unlinked zettel.

To retrieve unlinked references to an existing zettel, use the query ''{ID} UNLINKED''.

````
# curl 'http://127.0.0.1:23123/z?q=00001012000000+UNLINKED'
00001012921200 API: Encoding of Zettel Access Rights
````

This returns all zettel (in this case: only one) that references the title of the given Zettel, but does not references it directly.

In addition you may add __phrases__ if you do not want to scan for the title of the given zettel.

```
# curl 'http://localhost:23123/z?q=00001012054400+UNLINKED+PHRASE+API'
00001012050600 API: Provide an access token
00001012921200 API: Encoding of Zettel Access Rights
00001012080200 API: Check for authentication
00001012080500 API: Refresh internal data
00001012050200 API: Authenticate a client
00001010040700 Access token
```

This finds all zettel that does contain the phrase ""API"" but does not directly reference the given zettel.

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

id: 00001007770000
title: Query: Action List
role: manual
tags: #manual #search #zettelstore
syntax: zmk
created: 20230707205246
modified: 20230707205532

With a [[list of zettel identifier|00001007710000]], a [[query directives|00001007720000]], or a [[search expression|00001007701000]], a list of zettel is selected.
__Actions__ allow to modify this list to a certain degree.

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

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

id: 00001007780000
title: Formal syntax of query expressions
role: manual
tags: #manual #reference #search #zettelstore
syntax: zmk
created: 20220810144539
modified: 20230731160413

```
QueryExpression   := ZettelList? QueryDirective* SearchExpression ActionExpression?
ZettelList        := (ZID (SPACE+ ZID)*).
ZID               := '0'+ ('1' .. '9'') DIGIT*
                   | ('1' .. '9') DIGIT*.
QueryDirective    := ContextDirective
                   | IdentDirective
                   | ItemsDirective
                   | UnlinkedDirective.
ContextDirective  := "CONTEXT" (SPACE+ ContextDetail)*.
ContextDetail     := "BACKWARD"
                   | "FORWARD"
                   | "COST" SPACE+ PosInt
                   | "MAX" SPACE+ PosInt.
IdentDirective    := IDENT.
ItemsDirective    := ITEMS.
UnlinkedDirective := UNLINKED (SPACE+ PHRASE SPACE+ Word)*.
SearchExpression  := SearchTerm (SPACE+ SearchTerm)*.
SearchTerm        := SearchOperator? SearchValue
                   | SearchKey SearchOperator SearchValue?
                   | SearchKey ExistOperator
                   | "OR"
                   | "RANDOM"
                   | "PICK" SPACE+ PosInt
                   | "ORDER" SPACE+ ("REVERSE" SPACE+)? SearchKey
                   | "OFFSET" SPACE+ PosInt
                   | "LIMIT" SPACE+ PosInt.
SearchValue       := Word.
SearchKey         := MetadataKey.
SearchOperator    := '!'
                   | ('!')? ('~' | ':' | '[' | '}').
ExistOperator     := '?'
                   | '!' '?'.
PosInt            := '0'
                   | ('1' .. '9') DIGIT*.
ActionExpression  := '|' (Word (SPACE+ Word)*)?
Word              := NO-SPACE NO-SPACE*
```

id: 00001007790000
title: Useful query expressions
role: manual
tags: #example #manual #search #zettelstore
syntax: zmk
created: 20220810144539
modified: 20230706155134

|= Query Expression |= Meaning
| [[query:role:configuration]] | Zettel that contains some configuration data for the Zettelstore
| [[query:ORDER REVERSE created LIMIT 40]] | 40 recently created zettel
| [[query:ORDER REVERSE published LIMIT 40]] | 40 recently updated zettel
| [[query:PICK 40]] | 40 random zettel, ordered by zettel identifier
| [[query:dead?]] | Zettel with invalid / dead links
| [[query:backward!? precursor!?]] | Zettel that are not referenced by other zettel
| [[query:tags!?]] | Zettel without tags
| [[query:expire? ORDER expire]] | Zettel with an expire date, ordered from the nearest to the latest
| [[query:00001007700000 CONTEXT]] | Zettel within the context of the [[given zettel|00001007700000]]

: Only the metadata of a zettel is ""parsed"".
  Useful for displaying the full metadata.
  The [[runtime configuration zettel|00000000000100]] uses this syntax.
  The zettel content is ignored.
; [!svg|''svg'']
: [[Scalable Vector Graphics|https://www.w3.org/TR/SVG2/]].
; [!sxn|''sxn'']
: S-Expressions, as implemented by [[sx|https://zettelstore.de/sx]].
  Often used to specify templates when rendering a zettel as HTML for the [[web user interface|00001014000000]] (with the help of sxhtml]).
; [!text|''text''], [!plain|''plain''], [!txt|''txt'']
: Plain text that must not be interpreted further.
; [!zmk|''zmk'']
: [[Zettelmarkup|00001007000000]].

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

id: 00001012000000
title: API
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210126175322
modified: 20230731162018

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.

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


* [[Update metadata and content of a zettel|00001012054200]]
* [[Rename a zettel|00001012054400]]
* [[Delete a zettel|00001012054600]]

=== Various helper methods
* [[Retrieve administrative data|00001012070500]]
* [[Execute some commands|00001012080100]]
** [[Check for authentication|00001012080200]]
** [[Refresh internal data|00001012080500]]

id: 00001012051200
title: API: List all zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210126175322
modified: 20230703180113

To list all zettel just send a HTTP GET request to the [[endpoint|00001012920000]] ''/z''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header].
Always use the endpoint ''/z'' to work with a list of zettel.

Without further specifications, a plain text document is returned, with one line per zettel.
Each line contains in the first 14 characters the [[zettel identifier|00001006050000]].
Separated by a space character, the title of the zettel follows:

...
```

The list is **not** sorted, even in the these examples where it appears to be sorted.
If you want to have it ordered, you must specify it with the help of a [[query expression|00001007700000]] / [[search term|00001007702000]].
See [[Query the list of all zettel|00001012051400]] how to do it.

=== Data output

Alternatively, you may retrieve the zettel list as a parseable object / a [[symbolic expression|00001012930500]] by providing the query parameter ''enc=data'':

```sh
# curl 'http://127.0.0.1:23123/z?enc=data'
(meta-list (query "") (human "") (list (zettel (id "00001012921200") (meta (title "API: Encoding of Zettel Access Rights") (role "manual") (tags "#api #manual #reference #zettelstore") (syntax "zmk") (back "00001012051200 00001012051400 00001012053300 00001012053400 00001012053900 00001012054000") (backward "00001012051200 00001012051400 00001012053300 00001012053400 00001012053900 00001012054000") (box-number "1") (created "00010101000000") (forward "00001003000000 00001006020400 00001010000000 00001010040100 00001010040200 00001010070200 00001010070300") (modified "20220201171959") (published "20220201171959")) (rights 62)) (zettel (id "00001007030100") ...
```

Pretty-printed, this results in:
```
(meta-list (query "")
           (human "")
           (list (zettel (id "00001012921200")
                         (meta (title "API: Encoding of Zettel Access Rights")
                               (role "manual")
                               (tags "#api #manual #reference #zettelstore")
                               (syntax "zmk")
                               (back "00001012051200 00001012051400 00001012053300 00001012053400 00001012053900 00001012054000")
                               (backward "00001012051200 00001012051400 00001012053300 00001012053400 00001012053900 00001012054000")
                               (box-number "1")
                               (created "00010101000000")
                               (forward "00001003000000 00001006020400 00001010000000 00001010040100 00001010040200 00001010070200 00001010070300")
                               (modified "20220201171959")
                               (published "20220201171959"))
                         (rights 62))
                 (zettel (id "00001007030100")
```

* The result is a list, starting with the symbol ''meta-list''.
* Then, some key/value pairs are following, also nested.
* Keys ''query'' and ''human'' will be explained [[later in this manual|00001012051400]].
* ''list'' starts a list of zettel.
* ''zettel'' itself start, well, a zettel.
* ''id'' denotes the zettel identifier, encoded as a string.
* Nested in ''meta'' are the metadata, each as a key/value pair.
* ''rights'' specifies the [[access rights|00001012921200]] the user has for this zettel.

=== JSON output (deprecated)

Alternatively, you may retrieve the list of all zettel as a JSON object by specifying the encoding with the query parameter ''enc=json'':

```sh
# curl 'http://127.0.0.1:23123/z?enc=json'
{"query":"","human":"","list":[{"id":"00001012051200","meta":{"back":"00001012000000","backward":"00001012000000 00001012920000","box-number":"1","created":"20210126175322","forward":"00001006020000 00001006050000 00001007700000 00001010040100 00001012050200 00001012051400 00001012920000 00001012921000 00001014000000","modified":"20221219150626","published":"20221219150626","role":"manual","syntax":"zmk","tags":"#api #manual #zettelstore","title":"API: List all zettel"},"rights":62},{"id":"00001012050600","meta":{"back":"00001012000000 00001012080500","backward":"00001012000000 00001012080500","box-number":"1","created":"00010101000000","forward":"00001012050200 00001012921000","modified":"20220218130020","published":"20220218130020","role":"manual","syntax":"zmk","tags":"#api #manual #zettelstore","title":"API: Provide an access token"},"rights":62},{"id":"00001012050400","meta":{"back":"00001010040700 00001012000000","backward":"00001010040700 00001012000000 00001012920000 00001012921000","box-number":"1","created":"00010101000000","forward":"00001010040100 00001012050200 00001012920000 00001012921000","modified":"20220107215751","published":"20220107215751","role":"manual","syntax":"zmk","tags":"#api #manual #zettelstore","title":"API: Renew an access token"},"rights":62},{"id":"00001012050200","meta":{"back":"00001012000000 00001012050400 00001012050600 00001012051200 00001012051400 00001012053300 00001012053400 00001012053500 00001012053600 00001012080200","backward":"00001010040700 00001012000000 00001012050400 00001012050600 00001012051200 00001012051400 00001012053300 00001012053400 00001012053500 00001012053600 00001012080200 00001012920000 00001012921000","box-number":"1","created":"00010101000000","forward":"00001004010000 00001010040100 00001010040200 00001010040700 00001012920000 00001012921000","modified":"20220107215844","published":"20220107215844","role":"manual","syntax":"zmk","tags":"#api #manual #zettelstore","title":"API: Authenticate a client"},"rights":62}, ...]}
```

id: 00001012051400
title: API: Query the list of all zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20220912111111
modified: 20230731162234
precursor: 00001012051200

The [[endpoint|00001012920000]] ''/z'' also allows you to filter the list of all zettel[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header] and optionally to provide some actions.

A [[query|00001007700000]] is an optional [[search expression|00001007700000#search-expression]], together with an optional [[list of actions|00001007700000#action-list]] (described below).
An empty search expression will select all zettel.
An empty list of action, or no valid action, returns the list of all selected zettel metadata.

# curl 'http://127.0.0.1:23123/z?q=title%3AAPI+ORDER+REVERSE+id+OFFSET+1'
00001012921000 API: JSON structure of an access token
00001012920500 Formats available by the API
00001012920000 Endpoints used by the API
...
```

If you want to retrieve a data document, as a [[symbolic expression|00001012930500]]:

```sh
# curl 'http://127.0.0.1:23123/z?q=title%3AAPI+ORDER+REVERSE+id+OFFSET+1&enc=data'
(meta-list (query "title:API ORDER REVERSE id OFFSET 1") (human "title HAS API ORDER REVERSE id OFFSET 1") (list (zettel (id 1012921000) (meta (title "API: Structure of an access token") (role "manual") (tags "#api #manual #reference #zettelstore") (syntax "zmk") (back "00001012050600 00001012051200") (backward "00001012050200 00001012050400 00001012050600 00001012051200") (box-number "1") (created "20210126175322") (forward "00001012050200 00001012050400 00001012930000") (modified "20230412155303") (published "20230412155303")) (rights 62)) (zettel (id 1012920500) (meta (title "Encodings available via the API") (role "manual") (tags "#api #manual #reference #zettelstore") (syntax "zmk") (back "00001006000000 00001008010000 00001008010500 00001012053500 00001012053600") (backward "00001006000000 00001008010000 00001008010500 00001012053500 00001012053600") (box-number "1") (created "20210126175322") (forward "00001012000000 00001012920510 00001012920513 00001012920516 00001012920519 00001012920522 00001012920525") (modified "20230403123653") (published "20230403123653")) (rights 62)) (zettel (id 1012920000) (meta (title "Endpoints used by the API") ...
```

The data object contains a key ''"meta-list"'' to signal that it contains a list of metadata values (and some more).
It contains the keys ''"query"'' and ''"human"'' with a string value.
Both will contain a textual description of the underlying query if you select only some zettel with a [[query expression|00001007700000]].
Without a selection, the values are the empty string.
''"query"'' returns the normalized query expression itself, while ''"human"'' is the normalized query expression to be read by humans.
where its value is a list of zettel JSON objects.

The symbol ''list'' starts the list of zettel data.
Data of a zettel is indicated by the symbol ''zettel'', followed by ''(id ID)'' that describes the zettel identifier as a numeric value.
Leading zeroes are removed.
Metadata starts with the symbol ''meta'', and each metadatum itself is a list of metadata key / metadata value.
Metadata keys are encoded as a symbol, metadata values as a string.
''"rights"'' encodes the [[access rights|00001012921200]] for the given zettel.

If you want to retrieve a JSON document:

```sh
# curl 'http://127.0.0.1:23123/z?q=title%3AAPI+ORDER+REVERSE+id+OFFSET+1&enc=json'
{"query":"title:API ORDER REVERSE id OFFSET 1","human":"title HAS API ORDER REVERSE id OFFSET 1","list":[{"id":"00001012921200","meta":{"back":"00001012051200 00001012051400 00001012053300 00001012053400 00001012053800 00001012053900 00001012054000","backward":"00001012051200 00001012051400 00001012053300 00001012053400 00001012053800 00001012053900 00001012054000","box-number":"1","created":"00010101000000","forward":"00001003000000 00001006020400 00001010000000 00001010040100 00001010040200 00001010070200 00001010070300","modified":"20220201171959","published":"20220201171959","role":"manual","syntax":"zmk","tags":"#api #manual #reference #zettelstore","title":"API: Encoding of Zettel Access Rights"},"rights":62},{"id":"00001012921000","meta":{"back":"00001012050600 00001012051200","backward":"00001012050200 00001012050400 00001012050600 00001012051200","box-number":"1","created":"00010101000000","forward":"00001012050200 00001012050400","published":"00010101000000","role":"manual","syntax":"zmk","tags":"#api #manual #reference #zettelstore","title":"API: JSON structure of an access token"},"rights":62}, ...]
```

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

Additionally, the JSON object contains the keys ''"query"'' and ''"human"'' with a string value.




=== Aggregates

An implicit precondition is that the zettel must contain the given metadata key.
For a metadata key like [[''title''|00001006020000#title]], which have 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/z?q=url%3A'`` and ``curl 'http://localhost:23123/z?q=url%3A!'`` may result in an empty list.

The first word, separated by a horizontal tab (U+0009) contains the role name.
The rest of the line consists of zettel identifier, where the corresponding zettel have this role.
Zettel identifier are separated by a space character (U+0020).

Please note that the list is **not** sorted by the role name, so the same request might result in a different order.
If you want a sorted list, you could sort it on the command line (``curl 'http://127.0.0.1:23123/z?q=|role' | sort``) or within the software that made the call to the Zettelstore.

Of course, this list can also be returned as a data object:

```sh
# curl 'http://127.0.0.1:23123/z?q=|role&enc=data'
(aggregate "role" (query "| role") (human "| role") (list ("zettel" 10000000000 90001) ("configuration" 6 100 1000000100 20001 90 25001 92 4 40001 1 90000 5 90002) ("manual" 1008050000 1007031110 1008000000 1012920513 1005000000 1012931800 1010040700 1012931000 1012053600 1006050000 1012050200 1012000000 1012070500 1012920522 1006032500 1006020100 1007906000 1007030300 1012051400 1007040350 1007040324 1007706000 1012931900 1006030500 1004050200 1012054400 1007700000 1004050000 1006020000 1007030400 1012080100 1012920510 1007790000 1010070400 1005090000 1004011400 1006033000 1012930500 1001000000 1007010000 1006020400 1007040300 1010070300 1008010000 1003305000 1006030000 1006034000 1012054200 1012080200 1004010000 1003300000 1006032000 1003310000 1004059700 1007031000 1003600000 1004000000 1007030700 1007000000 1006055000 1007050200 1006036000 1012050600 1006000000 1012053900 1012920500 1004050400 1007031100 1007040340 1007020000 1017000000 1012053200 1007030600 1007040320 1003315000 1012054000 1014000000 1007030800 1010000000 1007903000 1010070200 1004051200 1007040330 1004051100 1004051000 1007050100 1012080500 1012053400 1006035500 1012054600 1004100000 1010040200 1012920000 1012920525 1004051400 1006031500 1012921200 1008010500 1012921000 1018000000 1012051200 1010040100 1012931200 1012920516 1007040310 1007780000 1007030200 1004101000 1012920800 1007030100 1007040200 1012053500 1007040000 1007040322 1007031300 1007031140 1012931600 1012931400 1004059900 1003000000 1006036500 1004020200 1010040400 1006033500 1000000000 1012053300 1007990000 1010090100 1007900000 1007030500 1004011600 1012930000 1007030900 1004020000 1007030000 1010070600 1007040100 1007800000 1012050400 1006010000 1007705000 1007702000 1007050000 1002000000 1007031200 1006035000 1006031000 1006034500 1004011200 1007031400 1012920519)))
```

The data object starts with the symbol ''aggregate'' to signal a different format compared to ''meta-list'' above.
Then a string follows, which specifies the key on which the aggregate was performed.
''query'' and ''human'' have the same meaning as above.
The ''symbol'' list starts the result list of aggregates.
Each aggregate starts with a string of the aggregate value, in this case the role value, followed by a list of zettel identifier, denoting zettel which have the given role value.

Similar, to list all tags used in the Zettelstore, send a HTTP GET request to the endpoint ''/z?q=|tags''.
If successful, the output is a data object:

```sh
# curl 'http://127.0.0.1:23123/z?q=|tags&enc=data'
(aggregate "tags" (query "| tags") (human "| tags") (list ("#zettel" 1006034500 1006034000 1006031000 1006020400 1006033500 1006036500 1006032500 1006020100 1006031500 1006030500 1006035500 1006033000 1006020000 1006036000 1006030000 1006032000 1006035000) ("#reference" 1006034500 1006034000 1007800000 1012920500 1006031000 1012931000 1006020400 1012930000 1006033500 1012920513 1007050100 1012920800 1007780000 1012921000 1012920510 1007990000 1006036500 1006032500 1006020100 1012931400 1012931800 1012920516 1012931600 1012920525 1012931200 1006031500 1012931900 1012920000 1005090000 1012920522 1006030500 1007050200 1012921200 1006035500 1012920519 1006033000 1006020000 1006036000 1006030000 1006032000 1012930500 1006035000) ("#graphic" 1008050000) ("#search" 1007700000 1007705000 1007790000 1007780000 1007702000 1007706000 1007031140) ("#installation" 1003315000 1003310000 1003000000 1003305000 1003300000 1003600000) ("#zettelmarkup" 1007900000 1007030700 1007031300 1007030600 1007800000 1007000000 1007031400 1007040100 1007030300 1007031200 1007040350 1007030400 1007030900 1007050100 1007040000 1007030500 1007903000 1007040200 1007040330 1007990000 1007040320 1007050000 1007040310 1007031100 1007040340 1007020000 1007031110 1007031140 1007040324 1007030800 1007031000 1007030000 1007010000 1007906000 1007050200 1007030100 1007030200 1007040300 1007040322) ("#design" 1005000000 1006000000 1002000000 1006050000 1006055000) ("#markdown" 1008010000 1008010500) ("#goal" 1002000000) ("#syntax" 1006010000) ...
```

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

Of course, this list can also be returned as a JSON object:

```sh
# curl 'http://127.0.0.1:23123/z?q=|role&enc=json'
{"map":{"configuration":["00000000090002","00000000090000", ... ,"00000000000001"],"manual":["00001014000000", ... ,"00001000000000"],"zettel":["00010000000000", ... ,"00001012070500","00000000090001"]}}
```

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

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

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

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


=== Actions

There are two types of actions: parameters and aggregates.
The following actions are supported:
; ''MINn'' (parameter)
: Emit only those values with at least __n__ aggregated values.
  __n__ must be a positive integer, ''MIN'' must be given in upper-case letters.
; ''MAXn'' (parameter)

id: 00001012053200
title: API: Create a new zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210713150005
modified: 20230807124310

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


The zettel must be encoded in a [[plain|00001006000000]] format: first comes the [[metadata|00001006010000]] and the following content is separated by an empty line.
This is the same format as used by storing zettel within a [[directory box|00001006010000]].

```
# curl -X POST --data $'title: Note\n\nImportant content.' http://127.0.0.1:23123/z
20210903211500
```

The zettel identifier of the created zettel is returned.
In addition, the HTTP response header contains a key ''Location'' with a relative URL for the new zettel.
A client must prepend the HTTP protocol scheme, the host name, and (optional, but often needed) the post number to make it an absolute URL.

=== Data input
Alternatively, you may encode the zettel as a parseable object / a [[symbolic expression|00001012930500]] by providing the query parameter ''enc=data''.
The encoding is the same as the data output encoding when you [[retrieve a zettel|00001012053300#data-output]].

The encoding for [[access rights|00001012921200]] must be given, but is ignored.
You may encode computed or property [[metadata keys|00001006020000]], but these are also ignored.

=== JSON input (deprecated)
Alternatively, the body of the POST request may contain a JSON object that specifies metadata and content of the zettel to be created.
To do this, you must add the query parameter ''enc=json''.
The following keys of the JSON object are used:
; ''"meta"''
: References an embedded JSON object with only string values.
  The name/value pairs of this objects are interpreted as the metadata of the new zettel.
  Please consider the [[list of supported metadata keys|00001006020000]] (and their value types).

id: 00001012053300
title: API: Retrieve metadata and content of an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20211004093206
modified: 20230807123533

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

For example, to retrieve some data about this zettel you are currently viewing, just send a HTTP GET request to the endpoint ''/z/00001012053300''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header].

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

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

For example, to retrieve some data about this zettel you are currently viewing, just send a HTTP GET request to the endpoint
...
````

=== Data output

Alternatively, you may retrieve the zettel as a parseable object / a [[symbolic expression|00001012930500]] by providing the query parameter ''enc=data'':

```sh
# curl 'http://127.0.0.1:23123/z/00001012053300?enc=data&part=zettel'
(zettel (meta (back "00001006000000 00001012000000 00001012053200 00001012054400") (backward "00001006000000 00001012000000 00001012053200 00001012054400 00001012920000") (box-number "1") (created "20211004093206") (forward "00001006020000 00001006050000 00001010040100 00001012050200 00001012053400 00001012920000 00001012920800 00001012921200 00001012930500") (modified "20230703174152") (published "20230703174152") (role "manual") (syntax "zmk") (tags "#api #manual #zettelstore") (title "API: Retrieve metadata and content of an existing zettel")) (rights 62) (encoding "") (content "The [[endpoint|00001012920000]] to work with metadata and content of a specific zettel is ''/z/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]].\n\nFor example, ...
```

If you print the result a little bit nicer, you will see its structure:
```
(zettel (meta (back "00001006000000 00001012000000 00001012053200 00001012054400")
              (backward "00001006000000 00001012000000 00001012053200 00001012054400 00001012920000")
              (box-number "1")
              (created "20211004093206")
              (forward "00001006020000 00001006050000 00001010040100 00001012050200 00001012053400 00001012920000 00001012920800 00001012921200 00001012930500")
              (modified "20230703174152")
              (published "20230703174152")
              (role "manual")
              (syntax "zmk")
              (tags "#api #manual #zettelstore")
              (title "API: Retrieve metadata and content of an existing zettel"))
        (rights 62)
        (encoding "")
        (content "The [[endpoint|00001012920000]] to work with metadata and content of a specific zettel is ''/z/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]].\n\nFor example, ...
```

* The result is a list, starting with the symbol ''zettel''.
* Then, some key/value pairs are following, also nested.
* Nested in ''meta'' are the metadata, each as a key/value pair.
* ''rights'' specifies the [[access rights|00001012921200]] the user has for this zettel.
* ''"encoding"'' states how the content is encoded.
  Currently, only two values are allowed: the empty string (''""'') that specifies an empty encoding, and the string ''"base64"'' that specifies the [[standard Base64 encoding|https://www.rfc-editor.org/rfc/rfc4648.txt]].
* The zettel contents is stored as a value of the key ''content''.
  Typically, text content is not encoded, and binary content is encoded via Base64.

=== JSON output (deprecated)

You may also retrieve the zettel as a JSON object by providing the query parameter ''enc=json'':
```sh
# curl 'http://127.0.0.1:23123/z/00001012053300?enc=json&part=zettel'
{"id":"00001012053300","meta":{"back":"00001012000000 00001012054400","backward":"00001012000000 00001012054400 00001012920000","box-number":"1","created":"20211004093206","forward":"00001006020000 00001006050000 00001010040100 00001012050200 00001012053400 00001012920000 00001012920800 00001012921200","modified":"20221219160211","published":"20221219160211","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 ''/z/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]].\n\nFor example, ...
```

Pretty-printed, this results in:
```

; ''"meta"''
: References an embedded JSON object with only string values.
  The name/value pairs of this objects are interpreted as the metadata of the new zettel.
  Please consider the [[list of supported metadata keys|00001006020000]] (and their value types).
; ''"encoding"''
: States how the content is encoded.
  Currently, only two values are allowed: the empty string (''""'') that specifies an empty encoding, and the string ''"base64"'' that specifies the [[standard Base64 encoding|https://www.rfc-editor.org/rfc/rfc4648.txt]].

; ''"content"''
: Is a string value that contains the content of the zettel to be created.
  Typically, text content is not encoded, and binary content is encoded via Base64.
; ''"rights"''
: An integer number that describes the [[access rights|00001012921200]] for the zettel.

=== HTTP Status codes

id: 00001012053400
title: API: Retrieve metadata of an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210726174524
modified: 20230703175153

The [[endpoint|00001012920000]] to work with metadata of a specific zettel is ''/z/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]][^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header].

To retrieve the plain metadata of a zettel, use the query parameter ''part=meta''

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

=== Data output

Alternatively, you may retrieve the zettel as a parseable object / a [[symbolic expression|00001012930500]] by providing the query parameter ''enc=data'':

```sh
# curl 'http://127.0.0.1:23123/z/00001012053400?part=meta&enc=data'
(list (meta (title "API: Retrieve metadata of an existing zettel") (role "manual") (tags "#api #manual #zettelstore") (syntax "zmk") (back "00001012000000 00001012053300") (backward "00001012000000 00001012053300") (box-number "1") (created "20210726174524") (forward "00001006020000 00001006050000 00001010040100 00001012050200 00001012920000 00001012921200") (modified "20230703174515") (published "20230703174515")) (rights 62))
```

Pretty-printed, this results in:
```
(list (meta (title "API: Retrieve metadata of an existing zettel")
            (role "manual")
            (tags "#api #manual #zettelstore")
            (syntax "zmk")
            (back "00001012000000 00001012053300")
            (backward "00001012000000 00001012053300")
            (box-number "1")
            (created "20210726174524")
            (forward "00001006020000 00001006050000 00001010040100 00001012050200 00001012920000 00001012921200")
            (modified "20230703174515")
            (published "20230703174515"))
      (rights 62))
```

* The result is a list, starting with the symbol ''list''.
* Then, some key/value pairs are following, also nested.
* Nested in ''meta'' are the metadata, each as a key/value pair.
* ''rights'' specifies the [[access rights|00001012921200]] the user has for this zettel.

=== JSON output (deprecated)
To return a JSON object, use also the query parameter ''enc=json''.

```sh
# curl 'http://127.0.0.1:23123/z/00001012053400?part=meta&enc=json'
{"meta":{"back":"00001012000000 00001012053300","backward":"00001012000000 00001012053300","box-number":"1","created":"20210726174524","forward":"00001006020000 00001006050000 00001010040100 00001012050200 00001012920000 00001012921200","modified":"20230703174515","published":"20230703174515","role":"manual","syntax":"zmk","tags":"#api #manual #zettelstore","title":"API: Retrieve metadata of an existing zettel"},"rights":62}
```

Pretty-printed, this results in:
```
{
  "meta": {
    "back": "00001012000000 00001012053300",

id: 00001012054200
title: API: Update a zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210713150005
modified: 20230807124354

Updating metadata and content of a zettel is technically quite similar to [[creating a new zettel|00001012053200]].
In both cases you must provide the data for the new or updated zettel in the body of the HTTP request.

One difference is the endpoint.
The [[endpoint|00001012920000]] to update a zettel is ''/z/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]].
You must send a HTTP PUT request to that endpoint.

The zettel must be encoded in a [[plain|00001006000000]] format: first comes the [[metadata|00001006010000]] and the following content is separated by an empty line.
This is the same format as used by storing zettel within a [[directory box|00001006010000]].

```
# curl -X POST --data 'title: Updated Note\n\nUpdated content.' http://127.0.0.1:23123/z/00001012054200
```

=== Data input
Alternatively, you may encode the zettel as a parseable object / a [[symbolic expression|00001012930500]] by providing the query parameter ''enc=data''.
The encoding is the same as the data output encoding when you [[retrieve a zettel|00001012053300#data-output]].

The encoding for [[access rights|00001012921200]] must be given, but is ignored.
You may encode computed or property [[metadata keys|00001006020000]], but these are also ignored.

=== JSON input (deprecated)
Alternatively, you can use the JSON encoding by using the query parameter ''enc=json''.

```
# curl -X PUT --data '{}' 'http://127.0.0.1:23123/z/00001012054200?enc=json'
```
This will put some empty content and metadata to the zettel you are currently reading.
As usual, some metadata will be calculated if it is empty.

id: 00001012070500
title: Retrieve administrative data
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 00010101000000
modified: 20230701160903

The [[endpoint|00001012920000]] ''/x'' allows you to retrieve some (administrative) data.

Currently, you can only request Zettelstore version data.

````
# curl 'http://127.0.0.1:23123/x'
(0 13 0 "dev" "f781dc384b-dirty")
````

* Zettelstore conforms somehow to the Standard [[Semantic Versioning|https://semver.org/]].


  The first three digits contain the major, minor, and patch version as described in this standard.
* The first string contains additional information, e.g. ""dev"" for a development version, or ""preview"" for a preview version.
* The second string contains data to identify the version from a developers perspective.

If any of the three digits has the value -1, its semantic value is unknown.
Similar, the two string might be empty.

=== HTTP Status codes
; ''200''
: Retrieval was successful, the body contains an appropriate object.

id: 00001012920000
title: Endpoints used by the API
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
created: 20210126175322
modified: 20230731162343

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

The following letters are currently in use:

|= Letter:| Without zettel identifier | With [[zettel identifier|00001006050000]] | Mnemonic
| ''a'' | POST: [[client authentication|00001012050200]] | | **A**uthenticate
|       | PUT: [[renew access token|00001012050400]] |


| ''x'' | GET: [[retrieve administrative data|00001012070500]] | | E**x**ecute
|       | POST: [[execute command|00001012080100]]
| ''z'' | GET: [[list zettel|00001012051200]]/[[query zettel|00001012051400]] | GET: [[retrieve zettel|00001012053300]] | **Z**ettel
|       | POST: [[create new zettel|00001012053200]] | PUT: [[update zettel|00001012054200]]
|       |  | DELETE: [[delete zettel|00001012054600]]
|       |  | MOVE: [[rename zettel|00001012054400]]

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: 00001012930500
title: Syntax of Symbolic Expressions
role: manual
tags: #manual #reference #zettelstore
syntax: zmk
created: 20230403151127
modified: 20230703174218

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

Internally, lists are composed of __cells__.
A cell allows to store two values.

~~~draw
+---+---+   +---+---+         +---+---+
| V | N +-->| V | N +-->   -->| V |   |
+-+-+---+   +-+-+---+         +-+-+---+
  |           |                 |
  v           v                 v
+-------+   +-------+         +-------+
| Elem1 |   | Elem2 |         | ElemN |
+-------+   +-------+         +-------+
~~~

''V'' is a placeholder for a value, ''N'' is the reference to the next cell (also known as the rest / tail of the list).
Above list will be represented as an symbolic expression as ''(Elem1 Elem2 ... ElemN)''

An improper list will have a non-__nil__ reference to an atom as the very last element

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

=== See also
* Currently, Zettelstore uses [[sx|https://zettelstore.de/sx]] (""Symbolic eXPression Framework"") to implement symbolic expression.
  The project page might contain additional information about the full syntax.

  Zettelstore only uses lists, numbers, string, and symbols to represent zettel.

https://zettelstore.de/manual/. It is a live example of the zettelstore
software, running in read-only mode. You can download it separately and it is
possible to make it directly available for your local Zettelstore.

The software, including the manual, is licensed under the European Union Public
License 1.2 (or later). See the separate file LICENSE.txt.

To get in contact with the developer, send an email to ds@zettelstore.de.

package encoder

import (
	"errors"
	"fmt"
	"io"

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

// Encoder is an interface that allows to encode different parts of a zettel.
type Encoder interface {
	WriteZettel(io.Writer, *ast.ZettelNode, EvalMetaFunc) (int, error)

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

package encoder_test

import (
	"testing"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/config"
	"zettelstore.de/z/input"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"

	_ "zettelstore.de/z/parser/blob" // Allow to use BLOB parser.

package encoder_test

import (
	"fmt"
	"strings"
	"testing"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/sx.fossil/sxreader"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/config"
	"zettelstore.de/z/encoder"
	"zettelstore.de/z/input"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/zettel/meta"

	t.Helper()
	encdr := encoder.Create(encoderSz)
	exp, err := pe.encode(encdr)
	if err != nil {
		t.Error(err)
		return
	}
	val, err := sxreader.MakeReader(strings.NewReader(exp)).Read()
	if err != nil {
		t.Error(err)
		return
	}
	got := val.Repr()
	if exp != got {
		prefix := fmt.Sprintf("Test #%d", testNum)

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

import (
	"io"
	"strings"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/client.fossil/shtml"
	"zettelstore.de/sx.fossil"
	"zettelstore.de/sx.fossil/sxhtml"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/encoder"
	"zettelstore.de/z/encoder/szenc"
	"zettelstore.de/z/encoder/textenc"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/zettel/meta"
)

func (he *Encoder) WriteZettel(w io.Writer, zn *ast.ZettelNode, evalMeta encoder.EvalMetaFunc) (int, error) {
	hm, err := he.th.Transform(he.tx.GetMeta(zn.InhMeta, evalMeta))
	if err != nil {
		return 0, err
	}

	var isTitle ast.InlineSlice
	var htitle *sx.Pair
	plainTitle, hasTitle := zn.InhMeta.Get(api.KeyTitle)
	if hasTitle {
		isTitle = parser.ParseSpacedText(plainTitle)
		xtitle := he.tx.GetSz(&isTitle)
		htitle, err = he.th.Transform(xtitle)
		if err != nil {
			return 0, err
		}
	}

	xast := he.tx.GetSz(&zn.Ast)
	hast, err := he.th.Transform(xast)
	if err != nil {
		return 0, err
	}
	hen := he.th.Endnotes()

	sf := he.th.SymbolFactory()
	symAttr := sf.MustMake(sxhtml.NameSymAttr)

	head := sx.MakeList(sf.MustMake("head"))
	curr := head
	curr = curr.AppendBang(sx.Nil().Cons(sx.Nil().Cons(sx.Cons(sf.MustMake("charset"), sx.MakeString("utf-8"))).Cons(symAttr)).Cons(sf.MustMake("meta")))
	for elem := hm; elem != nil; elem = elem.Tail() {
		curr = curr.AppendBang(elem.Car())
	}
	var sb strings.Builder
	if hasTitle {
		he.textEnc.WriteInlines(&sb, &isTitle)
	} else {
		sb.Write(zn.Meta.Zid.Bytes())
	}
	_ = curr.AppendBang(sx.Nil().Cons(sx.MakeString(sb.String())).Cons(sf.MustMake("title")))

	body := sx.MakeList(sf.MustMake("body"))
	curr = body
	if hasTitle {
		curr = curr.AppendBang(htitle.Cons(sf.MustMake("h1")))
	}
	for elem := hast; elem != nil; elem = elem.Tail() {
		curr = curr.AppendBang(elem.Car())
	}
	if hen != nil {
		curr = curr.AppendBang(sx.Nil().Cons(sf.MustMake("hr")))
		_ = curr.AppendBang(hen)
	}

	doc := sx.MakeList(
		sf.MustMake(sxhtml.NameSymDoctype),
		sx.MakeList(sf.MustMake("html"), head, body),
	)

	gen := sxhtml.NewGenerator(sf, sxhtml.WithNewline)
	return gen.WriteHTML(w, doc)
}

// WriteMeta encodes meta data as HTML5.

	return 0, err
}

// WriteInlines writes an inline slice to the writer
func (he *Encoder) WriteInlines(w io.Writer, is *ast.InlineSlice) (int, error) {
	hobj, err := he.th.Transform(he.tx.GetSz(is))
	if err == nil {
		gen := sxhtml.NewGenerator(sx.FindSymbolFactory(hobj))
		length, err2 := gen.WriteListHTML(w, hobj)
		if err2 != nil {
			return length, err2
		}
		return length, nil
	}
	return 0, err
}

// Package mdenc encodes the abstract syntax tree back into Markdown.
package mdenc

import (
	"io"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/encoder"
	"zettelstore.de/z/zettel/meta"
)

func init() {
	encoder.Register(api.EncoderMD, func() encoder.Encoder { return Create() })

// Package shtmlenc encodes the abstract syntax tree into a s-expr which represents HTML.
package shtmlenc

import (
	"io"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/client.fossil/shtml"
	"zettelstore.de/sx.fossil"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/encoder"
	"zettelstore.de/z/encoder/szenc"
	"zettelstore.de/z/zettel/meta"
)

func init() {

	if err != nil {
		return 0, err
	}
	contentSHTML, err := enc.th.Transform(enc.tx.GetSz(&zn.Ast))
	if err != nil {
		return 0, err
	}
	result := sx.Cons(metaSHTML, contentSHTML)
	return result.Print(w)
}

// WriteMeta encodes meta data as s-expression.
func (enc *Encoder) WriteMeta(w io.Writer, m *meta.Meta, evalMeta encoder.EvalMetaFunc) (int, error) {
	metaSHTML, err := enc.th.Transform(enc.tx.GetMeta(m, evalMeta))
	if err != nil {

// Package szenc encodes the abstract syntax tree into a s-expr for zettel.
package szenc

import (
	"io"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/sx.fossil"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/encoder"
	"zettelstore.de/z/zettel/meta"
)

func init() {
	encoder.Register(api.EncoderSz, func() encoder.Encoder { return Create() })

	trans *Transformer
}

// WriteZettel writes the encoded zettel to the writer.
func (enc *Encoder) WriteZettel(w io.Writer, zn *ast.ZettelNode, evalMeta encoder.EvalMetaFunc) (int, error) {
	content := enc.trans.GetSz(&zn.Ast)
	meta := enc.trans.GetMeta(zn.InhMeta, evalMeta)
	return sx.MakeList(meta, content).Print(w)
}

// WriteMeta encodes meta data as s-expression.
func (enc *Encoder) WriteMeta(w io.Writer, m *meta.Meta, evalMeta encoder.EvalMetaFunc) (int, error) {
	return enc.trans.GetMeta(m, evalMeta).Print(w)
}

package szenc

import (
	"encoding/base64"
	"fmt"
	"strings"

	"zettelstore.de/client.fossil/attrs"
	"zettelstore.de/client.fossil/sz"
	"zettelstore.de/sx.fossil"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/encoder"
	"zettelstore.de/z/zettel/meta"
)

// NewTransformer returns a new transformer to create s-expressions from AST nodes.
func NewTransformer() *Transformer {
	sf := sx.MakeMappedFactory()
	t := Transformer{sf: sf}
	t.zetSyms.InitializeZettelSymbols(sf)

	t.mapVerbatimKindS = map[ast.VerbatimKind]*sx.Symbol{
		ast.VerbatimZettel:  t.zetSyms.SymVerbatimZettel,
		ast.VerbatimProg:    t.zetSyms.SymVerbatimProg,
		ast.VerbatimEval:    t.zetSyms.SymVerbatimEval,
		ast.VerbatimMath:    t.zetSyms.SymVerbatimMath,
		ast.VerbatimComment: t.zetSyms.SymVerbatimComment,
		ast.VerbatimHTML:    t.zetSyms.SymVerbatimHTML,
	}

	t.mapRegionKindS = map[ast.RegionKind]*sx.Symbol{
		ast.RegionSpan:  t.zetSyms.SymRegionBlock,
		ast.RegionQuote: t.zetSyms.SymRegionQuote,
		ast.RegionVerse: t.zetSyms.SymRegionVerse,
	}
	t.mapNestedListKindS = map[ast.NestedListKind]*sx.Symbol{
		ast.NestedListOrdered:   t.zetSyms.SymListOrdered,
		ast.NestedListUnordered: t.zetSyms.SymListUnordered,
		ast.NestedListQuote:     t.zetSyms.SymListQuote,
	}
	t.alignmentSymbolS = map[ast.Alignment]*sx.Symbol{
		ast.AlignDefault: t.zetSyms.SymCell,
		ast.AlignLeft:    t.zetSyms.SymCellLeft,
		ast.AlignCenter:  t.zetSyms.SymCellCenter,
		ast.AlignRight:   t.zetSyms.SymCellRight,
	}
	t.mapRefStateLink = map[ast.RefState]*sx.Symbol{
		ast.RefStateInvalid:  t.zetSyms.SymLinkInvalid,
		ast.RefStateZettel:   t.zetSyms.SymLinkZettel,
		ast.RefStateSelf:     t.zetSyms.SymLinkSelf,
		ast.RefStateFound:    t.zetSyms.SymLinkFound,
		ast.RefStateBroken:   t.zetSyms.SymLinkBroken,
		ast.RefStateHosted:   t.zetSyms.SymLinkHosted,
		ast.RefStateBased:    t.zetSyms.SymLinkBased,
		ast.RefStateQuery:    t.zetSyms.SymLinkQuery,
		ast.RefStateExternal: t.zetSyms.SymLinkExternal,
	}
	t.mapFormatKindS = map[ast.FormatKind]*sx.Symbol{
		ast.FormatEmph:   t.zetSyms.SymFormatEmph,
		ast.FormatStrong: t.zetSyms.SymFormatStrong,
		ast.FormatDelete: t.zetSyms.SymFormatDelete,
		ast.FormatInsert: t.zetSyms.SymFormatInsert,
		ast.FormatSuper:  t.zetSyms.SymFormatSuper,
		ast.FormatSub:    t.zetSyms.SymFormatSub,
		ast.FormatQuote:  t.zetSyms.SymFormatQuote,
		ast.FormatSpan:   t.zetSyms.SymFormatSpan,
	}
	t.mapLiteralKindS = map[ast.LiteralKind]*sx.Symbol{
		ast.LiteralZettel:  t.zetSyms.SymLiteralZettel,
		ast.LiteralProg:    t.zetSyms.SymLiteralProg,
		ast.LiteralInput:   t.zetSyms.SymLiteralInput,
		ast.LiteralOutput:  t.zetSyms.SymLiteralOutput,
		ast.LiteralComment: t.zetSyms.SymLiteralComment,
		ast.LiteralHTML:    t.zetSyms.SymLiteralHTML,
		ast.LiteralMath:    t.zetSyms.SymLiteralMath,
	}
	t.mapRefStateS = map[ast.RefState]*sx.Symbol{
		ast.RefStateInvalid:  t.zetSyms.SymRefStateInvalid,
		ast.RefStateZettel:   t.zetSyms.SymRefStateZettel,
		ast.RefStateSelf:     t.zetSyms.SymRefStateSelf,
		ast.RefStateFound:    t.zetSyms.SymRefStateFound,
		ast.RefStateBroken:   t.zetSyms.SymRefStateBroken,
		ast.RefStateHosted:   t.zetSyms.SymRefStateHosted,
		ast.RefStateBased:    t.zetSyms.SymRefStateBased,
		ast.RefStateQuery:    t.zetSyms.SymRefStateQuery,
		ast.RefStateExternal: t.zetSyms.SymRefStateExternal,
	}
	t.mapMetaTypeS = map[*meta.DescriptionType]*sx.Symbol{
		meta.TypeCredential:   t.zetSyms.SymTypeCredential,
		meta.TypeEmpty:        t.zetSyms.SymTypeEmpty,
		meta.TypeID:           t.zetSyms.SymTypeID,
		meta.TypeIDSet:        t.zetSyms.SymTypeIDSet,
		meta.TypeNumber:       t.zetSyms.SymTypeNumber,
		meta.TypeString:       t.zetSyms.SymTypeString,
		meta.TypeTagSet:       t.zetSyms.SymTypeTagSet,
		meta.TypeTimestamp:    t.zetSyms.SymTypeTimestamp,
		meta.TypeURL:          t.zetSyms.SymTypeURL,
		meta.TypeWord:         t.zetSyms.SymTypeWord,
		meta.TypeWordSet:      t.zetSyms.SymTypeWordSet,
		meta.TypeZettelmarkup: t.zetSyms.SymTypeZettelmarkup,
	}
	return &t
}

type Transformer struct {
	sf                 sx.SymbolFactory
	zetSyms            sz.ZettelSymbols
	mapVerbatimKindS   map[ast.VerbatimKind]*sx.Symbol
	mapRegionKindS     map[ast.RegionKind]*sx.Symbol
	mapNestedListKindS map[ast.NestedListKind]*sx.Symbol
	alignmentSymbolS   map[ast.Alignment]*sx.Symbol
	mapRefStateLink    map[ast.RefState]*sx.Symbol
	mapFormatKindS     map[ast.FormatKind]*sx.Symbol
	mapLiteralKindS    map[ast.LiteralKind]*sx.Symbol
	mapRefStateS       map[ast.RefState]*sx.Symbol
	mapMetaTypeS       map[*meta.DescriptionType]*sx.Symbol
	inVerse            bool
}

func (t *Transformer) GetSz(node ast.Node) *sx.Pair {
	switch n := node.(type) {
	case *ast.BlockSlice:
		return t.getBlockSlice(n)
	case *ast.InlineSlice:
		return t.getInlineSlice(*n)
	case *ast.ParaNode:
		return t.getInlineSlice(n.Inlines).Tail().Cons(t.zetSyms.SymPara)
	case *ast.VerbatimNode:
		return sx.MakeList(
			mapGetS(t, t.mapVerbatimKindS, n.Kind),
			t.getAttributes(n.Attrs),
			sx.MakeString(string(n.Content)),
		)
	case *ast.RegionNode:
		return t.getRegion(n)
	case *ast.HeadingNode:
		return sx.MakeList(
			t.zetSyms.SymHeading,
			sx.Int64(int64(n.Level)),
			t.getAttributes(n.Attrs),
			sx.MakeString(n.Slug),
			sx.MakeString(n.Fragment),
			t.getInlineSlice(n.Inlines),
		)
	case *ast.HRuleNode:
		return sx.MakeList(t.zetSyms.SymThematic, t.getAttributes(n.Attrs))
	case *ast.NestedListNode:
		return t.getNestedList(n)
	case *ast.DescriptionListNode:
		return t.getDescriptionList(n)
	case *ast.TableNode:
		return t.getTable(n)
	case *ast.TranscludeNode:
		return sx.MakeList(t.zetSyms.SymTransclude, t.getAttributes(n.Attrs), t.getReference(n.Ref))
	case *ast.BLOBNode:
		return t.getBLOB(n)
	case *ast.TextNode:
		return sx.MakeList(t.zetSyms.SymText, sx.MakeString(n.Text))
	case *ast.SpaceNode:
		if t.inVerse {
			return sx.MakeList(t.zetSyms.SymSpace, sx.MakeString(n.Lexeme))
		}
		return sx.MakeList(t.zetSyms.SymSpace)
	case *ast.BreakNode:
		if n.Hard {
			return sx.MakeList(t.zetSyms.SymHard)
		}
		return sx.MakeList(t.zetSyms.SymSoft)
	case *ast.LinkNode:
		return t.getLink(n)
	case *ast.EmbedRefNode:
		return t.getInlineSlice(n.Inlines).Tail().
			Cons(sx.MakeString(n.Syntax)).
			Cons(t.getReference(n.Ref)).
			Cons(t.getAttributes(n.Attrs)).
			Cons(t.zetSyms.SymEmbed)
	case *ast.EmbedBLOBNode:
		return t.getEmbedBLOB(n)
	case *ast.CiteNode:
		return t.getInlineSlice(n.Inlines).Tail().
			Cons(sx.MakeString(n.Key)).
			Cons(t.getAttributes(n.Attrs)).
			Cons(t.zetSyms.SymCite)
	case *ast.FootnoteNode:
		text := sx.Nil().Cons(sx.Nil().Cons(t.getInlineSlice(n.Inlines)).Cons(t.zetSyms.SymQuote))
		return text.Cons(t.getAttributes(n.Attrs)).Cons(t.zetSyms.SymEndnote)
	case *ast.MarkNode:
		return t.getInlineSlice(n.Inlines).Tail().
			Cons(sx.MakeString(n.Fragment)).
			Cons(sx.MakeString(n.Slug)).
			Cons(sx.MakeString(n.Mark)).
			Cons(t.zetSyms.SymMark)
	case *ast.FormatNode:
		return t.getInlineSlice(n.Inlines).Tail().
			Cons(t.getAttributes(n.Attrs)).
			Cons(mapGetS(t, t.mapFormatKindS, n.Kind))
	case *ast.LiteralNode:
		return sx.MakeList(
			mapGetS(t, t.mapLiteralKindS, n.Kind),
			t.getAttributes(n.Attrs),
			sx.MakeString(string(n.Content)),
		)
	}
	return sx.MakeList(t.zetSyms.SymUnknown, sx.MakeString(fmt.Sprintf("%T %v", node, node)))
}

func (t *Transformer) getRegion(rn *ast.RegionNode) *sx.Pair {
	saveInVerse := t.inVerse
	if rn.Kind == ast.RegionVerse {
		t.inVerse = true
	}
	symBlocks := t.GetSz(&rn.Blocks)
	t.inVerse = saveInVerse
	return sx.MakeList(
		mapGetS(t, t.mapRegionKindS, rn.Kind),
		t.getAttributes(rn.Attrs),
		symBlocks,
		t.GetSz(&rn.Inlines),
	)
}

func (t *Transformer) getNestedList(ln *ast.NestedListNode) *sx.Pair {
	nlistObjs := make([]sx.Object, len(ln.Items)+1)
	nlistObjs[0] = mapGetS(t, t.mapNestedListKindS, ln.Kind)
	isCompact := isCompactList(ln.Items)
	for i, item := range ln.Items {
		if isCompact && len(item) > 0 {
			paragraph := t.GetSz(item[0])
			nlistObjs[i+1] = paragraph.Tail().Cons(t.zetSyms.SymInline)
			continue
		}
		itemObjs := make([]sx.Object, len(item))
		for j, in := range item {
			itemObjs[j] = t.GetSz(in)
		}
		if isCompact {
			nlistObjs[i+1] = sx.MakeList(itemObjs...).Cons(t.zetSyms.SymInline)
		} else {
			nlistObjs[i+1] = sx.MakeList(itemObjs...).Cons(t.zetSyms.SymBlock)
		}
	}
	return sx.MakeList(nlistObjs...)
}
func isCompactList(itemSlice []ast.ItemSlice) bool {
	for _, items := range itemSlice {
		if len(items) > 1 {
			return false
		}
		if len(items) == 1 {
			if _, ok := items[0].(*ast.ParaNode); !ok {
				return false
			}
		}
	}
	return true
}

func (t *Transformer) getDescriptionList(dn *ast.DescriptionListNode) *sx.Pair {
	dlObjs := make([]sx.Object, 2*len(dn.Descriptions)+1)
	dlObjs[0] = t.zetSyms.SymDescription
	for i, def := range dn.Descriptions {
		dlObjs[2*i+1] = t.getInlineSlice(def.Term)
		descObjs := make([]sx.Object, len(def.Descriptions))
		for j, b := range def.Descriptions {
			dVal := make([]sx.Object, len(b))
			for k, dn := range b {
				dVal[k] = t.GetSz(dn)
			}
			descObjs[j] = sx.MakeList(dVal...).Cons(t.zetSyms.SymBlock)
		}
		dlObjs[2*i+2] = sx.MakeList(descObjs...).Cons(t.zetSyms.SymBlock)
	}
	return sx.MakeList(dlObjs...)
}

func (t *Transformer) getTable(tn *ast.TableNode) *sx.Pair {
	tObjs := make([]sx.Object, len(tn.Rows)+2)
	tObjs[0] = t.zetSyms.SymTable
	tObjs[1] = t.getHeader(tn.Header)
	for i, row := range tn.Rows {
		tObjs[i+2] = t.getRow(row)
	}
	return sx.MakeList(tObjs...)
}
func (t *Transformer) getHeader(header ast.TableRow) *sx.Pair {
	if len(header) == 0 {
		return nil
	}
	return t.getRow(header)
}
func (t *Transformer) getRow(row ast.TableRow) *sx.Pair {
	rObjs := make([]sx.Object, len(row))
	for i, cell := range row {
		rObjs[i] = t.getCell(cell)
	}
	return sx.MakeList(rObjs...).Cons(t.zetSyms.SymList)
}

func (t *Transformer) getCell(cell *ast.TableCell) *sx.Pair {
	return t.getInlineSlice(cell.Inlines).Tail().Cons(mapGetS(t, t.alignmentSymbolS, cell.Align))
}

func (t *Transformer) getBLOB(bn *ast.BLOBNode) *sx.Pair {
	var lastObj sx.Object
	if bn.Syntax == meta.SyntaxSVG {
		lastObj = sx.MakeString(string(bn.Blob))
	} else {
		lastObj = getBase64String(bn.Blob)
	}
	return sx.MakeList(
		t.zetSyms.SymBLOB,
		t.getInlineSlice(bn.Description),
		sx.MakeString(bn.Syntax),
		lastObj,
	)
}

func (t *Transformer) getLink(ln *ast.LinkNode) *sx.Pair {
	return t.getInlineSlice(ln.Inlines).Tail().
		Cons(sx.MakeString(ln.Ref.Value)).
		Cons(t.getAttributes(ln.Attrs)).
		Cons(mapGetS(t, t.mapRefStateLink, ln.Ref.State))
}

func (t *Transformer) getEmbedBLOB(en *ast.EmbedBLOBNode) *sx.Pair {
	tail := t.getInlineSlice(en.Inlines).Tail()
	if en.Syntax == meta.SyntaxSVG {
		tail = tail.Cons(sx.MakeString(string(en.Blob)))
	} else {
		tail = tail.Cons(getBase64String(en.Blob))
	}
	return tail.Cons(sx.MakeString(en.Syntax)).Cons(t.getAttributes(en.Attrs)).Cons(t.zetSyms.SymEmbedBLOB)
}

func (t *Transformer) getBlockSlice(bs *ast.BlockSlice) *sx.Pair {
	objs := make([]sx.Object, len(*bs))
	for i, n := range *bs {
		objs[i] = t.GetSz(n)
	}
	return sx.MakeList(objs...).Cons(t.zetSyms.SymBlock)
}
func (t *Transformer) getInlineSlice(is ast.InlineSlice) *sx.Pair {
	objs := make([]sx.Object, len(is))
	for i, n := range is {
		objs[i] = t.GetSz(n)
	}
	return sx.MakeList(objs...).Cons(t.zetSyms.SymInline)
}

func (t *Transformer) getAttributes(a attrs.Attributes) sx.Object {
	if a.IsEmpty() {
		return sx.Nil()
	}
	keys := a.Keys()
	objs := make([]sx.Object, 0, len(keys))
	for _, k := range keys {
		objs = append(objs, sx.Cons(sx.MakeString(k), sx.MakeString(a[k])))
	}
	return sx.Nil().Cons(sx.MakeList(objs...)).Cons(t.zetSyms.SymQuote)
}

func (t *Transformer) getReference(ref *ast.Reference) *sx.Pair {
	return sx.MakeList(
		t.zetSyms.SymQuote,
		sx.MakeList(
			mapGetS(t, t.mapRefStateS, ref.State),
			sx.MakeString(ref.Value),
		),
	)
}

func (t *Transformer) GetMeta(m *meta.Meta, evalMeta encoder.EvalMetaFunc) *sx.Pair {
	pairs := m.ComputedPairs()
	objs := make([]sx.Object, 0, len(pairs))
	for _, p := range pairs {
		key := p.Key
		ty := m.Type(key)
		symType := mapGetS(t, t.mapMetaTypeS, ty)
		var obj sx.Object
		if ty.IsSet {
			setList := meta.ListFromValue(p.Value)
			setObjs := make([]sx.Object, len(setList))
			for i, val := range setList {
				setObjs[i] = sx.MakeString(val)
			}
			obj = sx.MakeList(setObjs...).Cons(t.zetSyms.SymList)
		} else if ty == meta.TypeZettelmarkup {
			is := evalMeta(p.Value)
			obj = t.GetSz(&is)
		} else {
			obj = sx.MakeString(p.Value)
		}
		symKey := sx.MakeList(t.zetSyms.SymQuote, t.sf.MustMake(key))
		objs = append(objs, sx.Nil().Cons(obj).Cons(symKey).Cons(symType))
	}
	return sx.MakeList(objs...).Cons(t.zetSyms.SymMeta)
}

func mapGetS[T comparable](t *Transformer, m map[T]*sx.Symbol, k T) *sx.Symbol {
	if result, found := m[k]; found {
		return result
	}
	return t.sf.MustMake(fmt.Sprintf("**%v:NOT-FOUND**", k))
}

func getBase64String(data []byte) sx.String {
	var sb strings.Builder
	encoder := base64.NewEncoder(base64.StdEncoding, &sb)
	_, err := encoder.Write(data)
	if err == nil {
		err = encoder.Close()
	}
	if err == nil {
		return sx.MakeString(sb.String())
	}
	return sx.MakeString("")
}

// Package textenc encodes the abstract syntax tree into its text.
package textenc

import (
	"io"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/encoder"
	"zettelstore.de/z/zettel/meta"
)

func init() {
	encoder.Register(api.EncoderText, func() encoder.Encoder { return Create() })

package zmkenc

import (
	"fmt"
	"io"
	"strings"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/client.fossil/attrs"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/encoder"
	"zettelstore.de/z/encoder/textenc"
	"zettelstore.de/z/strfun"
	"zettelstore.de/z/zettel/meta"
)

// Package atom provides an Atom encoding.
package atom

import (
	"bytes"
	"time"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/config"
	"zettelstore.de/z/encoding"
	"zettelstore.de/z/encoding/xml"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/query"
	"zettelstore.de/z/strfun"
	"zettelstore.de/z/zettel/id"

// Package encoding provides helper functions for encodings.
package encoding

import (
	"time"

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

// LastUpdated returns the formated time of the zettel which was updated at the latest time.
func LastUpdated(ml []*meta.Meta, timeFormat string) string {

package rss

import (
	"bytes"
	"context"
	"time"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/config"
	"zettelstore.de/z/encoding"
	"zettelstore.de/z/encoding/xml"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/query"
	"zettelstore.de/z/strfun"
	"zettelstore.de/z/zettel/id"

	"context"
	"errors"
	"fmt"
	"path"
	"strconv"
	"strings"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/client.fossil/attrs"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/box"
	"zettelstore.de/z/config"
	"zettelstore.de/z/input"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/parser/cleaner"
	"zettelstore.de/z/parser/draw"
	"zettelstore.de/z/query"
	"zettelstore.de/z/zettel"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

// Port contains all methods to retrieve zettel (or part of it) to evaluate a zettel.
type Port interface {

	GetZettel(context.Context, id.Zid) (zettel.Zettel, error)
	QueryMeta(ctx context.Context, q *query.Query) ([]*meta.Meta, error)
}

// EvaluateZettel evaluates the given zettel in the given context, with the
// given ports, and the given environment.
func EvaluateZettel(ctx context.Context, port Port, rtConfig config.Config, zn *ast.ZettelNode) {
	if zn.Syntax == meta.SyntaxNone {
		// AST is empty, evaluate to a description list of metadata.

		e.transcludeCount += cost.ec
	}
	return &zn.Ast
}

func (e *evaluator) evalQueryTransclusion(expr string) ast.BlockNode {
	q := query.Parse(expr)
	ml, err := e.port.QueryMeta(e.ctx, q)
	if err != nil {
		if errors.Is(err, &box.ErrNotAllowed{}) {
			return nil
		}
		return makeBlockNode(createInlineErrorText(nil, "Unable", "to", "search", "zettel"))
	}
	result := QueryAction(e.ctx, q, ml, e.rtConfig)

	}
	ref := ln.Ref
	if ref == nil || ref.State != ast.RefStateZettel {
		return ln
	}

	zid := mustParseZid(ref)
	_, err := e.port.GetZettel(box.NoEnrichContext(e.ctx), zid)
	if errors.Is(err, &box.ErrNotAllowed{}) {
		return &ast.FormatNode{
			Kind:    ast.FormatSpan,
			Attrs:   ln.Attrs,
			Inlines: getLinkInline(ln),
		}
	} else if err != nil {

	"bytes"
	"context"
	"math"
	"sort"
	"strconv"
	"strings"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/client.fossil/attrs"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/config"
	"zettelstore.de/z/encoding/atom"
	"zettelstore.de/z/encoding/rss"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/query"
	"zettelstore.de/z/zettel/meta"

module zettelstore.de/z

go 1.20

require (


	github.com/fsnotify/fsnotify v1.6.0

	github.com/yuin/goldmark v1.5.5
	golang.org/x/crypto v0.12.0
	golang.org/x/term v0.11.0
	golang.org/x/text v0.12.0
	zettelstore.de/client.fossil v0.0.0-20230807134407-92d8dd7df841
	zettelstore.de/sx.fossil v0.0.0-20230727172325-adec5a7ba284
)

require golang.org/x/sys v0.11.0 // indirect

github.com/fsnotify/fsnotify v1.6.0 h1:n+5WquG0fcWoWp6xPWfHdbskMCQaFnG6PfBrh1Ky4HY=
github.com/fsnotify/fsnotify v1.6.0/go.mod h1:sl3t1tCWJFWoRz9R8WJCbQihKKwmorjAbSClcnxKAGw=


github.com/yuin/goldmark v1.5.5 h1:IJznPe8wOzfIKETmMkd06F8nXkmlhaHqFRM9l1hAGsU=
github.com/yuin/goldmark v1.5.5/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
golang.org/x/crypto v0.12.0 h1:tFM/ta59kqch6LlvYnPa0yx5a83cL2nHflFhYKvv9Yk=
golang.org/x/crypto v0.12.0/go.mod h1:NF0Gs7EO5K4qLn+Ylc+fih8BSTeIjAP05siRnAh98yw=
golang.org/x/sys v0.0.0-20220908164124-27713097b956/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.11.0 h1:eG7RXZHdqOJ1i+0lgLgCpSXAp6M3LYlAo6osgSi0xOM=
golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/term v0.11.0 h1:F9tnn/DA/Im8nCwm+fX+1/eBwi4qFjRT++MhtVC4ZX0=
golang.org/x/term v0.11.0/go.mod h1:zC9APTIj3jG3FdV/Ons+XE1riIZXG4aZ4GTHiPZJPIU=
golang.org/x/text v0.12.0 h1:k+n5B8goJNdU7hSvEtMUz3d1Q6D/XW4COJSJR6fN0mc=
golang.org/x/text v0.12.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
zettelstore.de/client.fossil v0.0.0-20230807134407-92d8dd7df841 h1:QlOIlT2cURqM2nYEvL7zOrjiE5/ZA3iAAfslcd6u2PY=
zettelstore.de/client.fossil v0.0.0-20230807134407-92d8dd7df841/go.mod h1:MaVH7f0eHaWB5bK0GHNUiPJxKIYGyBk9amBUSbDZM0g=
zettelstore.de/sx.fossil v0.0.0-20230727172325-adec5a7ba284 h1:26xwZWEjdyL3wObczc/PKugv0EY6mgSH5NUe5kYFCt4=
zettelstore.de/sx.fossil v0.0.0-20230727172325-adec5a7ba284/go.mod h1:nsWXVrQG8RNKtoXzEMrWXNMdnpfIDU6Hb0pk56KpVKE=

	"context"
	"errors"
	"fmt"
	"strconv"
	"strings"
	"sync"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/box"
	"zettelstore.de/z/config"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/web/server"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"

func (cs *configService) setBox(mgr box.Manager) {
	mgr.RegisterObserver(cs.observe)
	cs.observe(box.UpdateInfo{Box: mgr, Reason: box.OnZettel, Zid: id.ConfigurationZid})
}

func (cs *configService) doUpdate(p box.BaseBox) error {
	z, err := p.GetZettel(context.Background(), cs.orig.Zid)
	cs.logger.Trace().Err(err).Msg("got config meta")
	if err != nil {
		return err
	}
	m := z.Meta
	cs.mxService.Lock()
	for _, pair := range cs.orig.Pairs() {
		key := pair.Key
		if val, ok := m.Get(key); ok {
			cs.SetConfig(key, val)
		} else if defVal, defFound := cs.orig.Get(key); defFound {
			cs.SetConfig(key, defVal)

	"io"
	"os"
	"runtime/metrics"
	"sort"
	"strconv"
	"strings"

	"zettelstore.de/client.fossil/maps"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/strfun"
)

type cmdSession struct {
	w        io.Writer

	"errors"
	"fmt"
	"sort"
	"strconv"
	"strings"
	"sync"

	"zettelstore.de/client.fossil/maps"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/zettel/id"
)

type parseFunc func(string) (any, error)
type configDescription struct {

	"fmt"
	"net"
	"os"
	"runtime"
	"sync"
	"time"

	"zettelstore.de/client.fossil/maps"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/logger"
	"zettelstore.de/z/strfun"
	"zettelstore.de/z/zettel/id"
)

type coreService struct {

func (kern *myKernel) Setup(progname, version string, versionTime time.Time) {
	kern.SetConfig(kernel.CoreService, kernel.CoreProgname, progname)
	kern.SetConfig(kernel.CoreService, kernel.CoreVersion, version)
	kern.SetConfig(kernel.CoreService, kernel.CoreVTime, versionTime.Local().Format(id.ZidLayout))
}

func (kern *myKernel) Start(headline, lineServer bool, configFilename string) {
	for _, srvD := range kern.srvs {
		srvD.srv.Freeze()
	}
	if kern.cfg.GetCurConfig(kernel.ConfigSimpleMode).(bool) {
		kern.SetLogLevel(defaultSimpleLogLevel.String())
	}
	kern.wg.Add(1)

			kern.core.GetCurConfig(kernel.CoreProgname),
			kern.core.GetCurConfig(kernel.CoreVersion),
			kern.core.GetCurConfig(kernel.CoreGoVersion),
			kern.core.GetCurConfig(kernel.CoreGoOS),
			kern.core.GetCurConfig(kernel.CoreGoArch),
		))
		logger.Mandatory().Msg("Licensed under the latest version of the EUPL (European Union Public License)")
		if configFilename != "" {
			logger.Mandatory().Str("filename", configFilename).Msg("Configuration file found")
		} else {
			logger.Mandatory().Msg("No configuration file found / used")
		}
		if kern.core.GetCurConfig(kernel.CoreDebug).(bool) {
			logger.Warn().Msg("----------------------------------------")
			logger.Warn().Msg("DEBUG MODE, DO NO USE THIS IN PRODUCTION")
			logger.Warn().Msg("----------------------------------------")
		}
		if kern.auth.GetCurConfig(kernel.AuthReadonly).(bool) {
			logger.Info().Msg("Read-only mode")

// Kernel is the main internal service.
type Kernel interface {
	// Setup sets the most basic data of a software: its name, its version,
	// and when the version was created.
	Setup(progname, version string, versionTime time.Time)

	// Start the service.
	Start(headline bool, lineServer bool, configFile string)

	// WaitForShutdown blocks the call until Shutdown is called.
	WaitForShutdown()

	// Shutdown the service. Waits for all concurrent activities to stop.
	Shutdown(silent bool)

import (
	"context"
	"net/http"
	"strconv"
	"sync"

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

// Message presents a message to log.
type Message struct {
	logger *Logger
	level  Level

// It is not a parser registered by the general parser framework (directed by
// metadata "syntax" of a zettel). It will be used when a zettel is evaluated.
package draw

import (
	"strconv"

	"zettelstore.de/client.fossil/attrs"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/input"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/zettel/meta"
)

func init() {

	"strconv"
	"strings"

	gm "github.com/yuin/goldmark"
	gmAst "github.com/yuin/goldmark/ast"
	gmText "github.com/yuin/goldmark/text"

	"zettelstore.de/client.fossil/attrs"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/encoder/textenc"
	"zettelstore.de/z/input"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/zettel/meta"
)

package parser

import (
	"context"
	"fmt"
	"strings"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/config"
	"zettelstore.de/z/input"
	"zettelstore.de/z/parser/cleaner"
	"zettelstore.de/z/zettel"
	"zettelstore.de/z/zettel/meta"
)

// Package plain provides a parser for plain text data.
package plain

import (
	"bytes"
	"strings"

	"zettelstore.de/client.fossil/attrs"
	"zettelstore.de/sx.fossil/sxbuiltins/pprint"
	"zettelstore.de/sx.fossil/sxbuiltins/quote"

	"zettelstore.de/sx.fossil/sxreader"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/input"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/zettel/meta"
)

func init() {

		return ""
	}
	// TODO: check proper end </svg>
	return svgSrc
}

func parseSxnBlocks(inp *input.Input, _ *meta.Meta, syntax string) ast.BlockSlice {
	rd := sxreader.MakeReader(bytes.NewReader(inp.Src))
	sf := rd.SymbolFactory()
	quote.InstallQuoteReader(rd, sf.MustMake("quote"), '\'')
	quote.InstallQuasiQuoteReader(rd,
		sf.MustMake("quasiquote"), '`',
		sf.MustMake("unquote"), ',',
		sf.MustMake("unquote-splicing"), '@')
	objs, err := rd.ReadAll()

package zettelmark

import (
	"bytes"
	"fmt"
	"strings"

	"zettelstore.de/client.fossil/attrs"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/input"
	"zettelstore.de/z/zettel/meta"
)

// parseInlineSlice parses a sequence of Inlines until EOS.
func (cp *zmkP) parseInlineSlice() (ins ast.InlineSlice) {

// Package zettelmark provides a parser for zettelmarkup.
package zettelmark

import (
	"strings"
	"unicode"

	"zettelstore.de/client.fossil/attrs"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/input"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/zettel/meta"
)

func init() {

package zettelmark_test

import (
	"fmt"
	"strings"
	"testing"

	"zettelstore.de/client.fossil/attrs"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/config"
	"zettelstore.de/z/input"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/zettel/meta"
)

	hasQuery bool
	seed     int
	pick     int
	order    []sortOrder
	offset   int // <= 0: no offset
	limit    int // <= 0: no limit

	startMeta []*meta.Meta
	PreMatch  MetaMatchFunc // Precondition for Match and Retrieve
	Terms     []CompiledTerm
}

// MetaMatchFunc is a function determine whethe some metadata should be selected or not.
type MetaMatchFunc func(*meta.Meta) bool

func matchAlways(*meta.Meta) bool { return true }
func matchNever(*meta.Meta) bool  { return false }

// RetrievePredicate returns true, if the given Zid is contained in the (full-text) search.
type RetrievePredicate func(id.Zid) bool

func (c *Compiled) isDeterministic() bool { return c.seed > 0 }

// Result returns a result of the compiled search, that is achievable without iterating through a box.
func (c *Compiled) Result() []*meta.Meta {
	if len(c.startMeta) == 0 {
		// nil -> no directive
		// empty slice -> nothing found
		return c.startMeta
	}
	result := make([]*meta.Meta, 0, len(c.startMeta))
	for _, m := range c.startMeta {
		for _, term := range c.Terms {
			if term.Match(m) && term.Retrieve(m.Zid) {
				result = append(result, m)
				break
			}
		}
	}
	result = c.pickElements(result)
	result = c.sortElements(result)

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

package query

import (
	"context"

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

// ContextSpec contains all specification values for calculating a context.
type ContextSpec struct {
	Direction ContextDirection
	MaxCost   int
	MaxCount  int
}

// ContextDirection specifies the direction a context should be calculated.
type ContextDirection uint8

const (
	ContextDirBoth ContextDirection = iota
	ContextDirForward
	ContextDirBackward

)

// ContextPort is the collection of box methods needed by this directive.
type ContextPort interface {
	GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error)
	SelectMeta(ctx context.Context, metaSeq []*meta.Meta, q *Query) ([]*meta.Meta, error)


}

func (spec *ContextSpec) Print(pe *PrintEnv) {
	pe.printSpace()
	pe.writeString(api.ContextDirective)


	switch spec.Direction {
	case ContextDirBackward:
		pe.printSpace()
		pe.writeString(api.BackwardDirective)
	case ContextDirForward:
		pe.printSpace()
		pe.writeString(api.ForwardDirective)
	}
	pe.printPosInt(api.CostDirective, spec.MaxCost)
	pe.printPosInt(api.MaxDirective, spec.MaxCount)


}

func (spec *ContextSpec) Execute(ctx context.Context, startSeq []*meta.Meta, port ContextPort) []*meta.Meta {
	maxCost := spec.MaxCost
	if maxCost <= 0 {
		maxCost = 17
	}
	maxCount := spec.MaxCount
	if maxCount <= 0 {
		maxCount = 200
	}
	tasks := newQueue(startSeq, maxCost, maxCount, port)
	isBackward := spec.Direction == ContextDirBoth || spec.Direction == ContextDirBackward
	isForward := spec.Direction == ContextDirBoth || spec.Direction == ContextDirForward
	result := []*meta.Meta{}
	for {
		m, cost := tasks.next()
		if m == nil {
			break
		}
		result = append(result, m)

		for _, p := range m.ComputedPairsRest() {
			tasks.addPair(ctx, p.Key, p.Value, cost, isBackward, isForward)
		}
		if tags, found := m.GetList(api.KeyTags); found {
			for _, tag := range tags {
				tasks.addSameTag(ctx, tag, cost)
			}
		}
	}
	return result
}

type ztlCtxTask struct {
	next *ztlCtxTask
	prev *ztlCtxTask
	meta *meta.Meta
	cost int
}

type contextQueue struct {

	port    ContextPort

	seen    id.Set
	first   *ztlCtxTask
	last    *ztlCtxTask
	maxCost int
	limit   int
	tagCost map[string][]*meta.Meta
}

func newQueue(startSeq []*meta.Meta, maxCost, limit int, port ContextPort) *contextQueue {






	result := &contextQueue{

		port:    port,

		seen:    id.NewSet(),
		first:   nil,
		last:    nil,
		maxCost: maxCost,
		limit:   limit,
		tagCost: make(map[string][]*meta.Meta, 1024),
	}

	var prev *ztlCtxTask
	for _, m := range startSeq {
		task := &ztlCtxTask{next: nil, prev: prev, meta: m, cost: 1}
		if prev == nil {
			result.first = task
		} else {
			prev.next = task
		}
		result.last = task
		prev = task
	}
	return result
}

func (zc *contextQueue) addPair(ctx context.Context, key, value string, curCost int, isBackward, isForward bool) {
	if key == api.KeyBack {
		return

	return 3
}

func (zc *contextQueue) addID(ctx context.Context, newCost int, value string) {
	if zc.costMaxed(newCost) {
		return
	}

	if zid, errParse := id.Parse(value); errParse == nil {



		if m, errGetMeta := zc.port.GetMeta(ctx, zid); errGetMeta == nil {

			zc.addMeta(m, newCost)
		}


	}
}
func (zc *contextQueue) addMeta(m *meta.Meta, newCost int) {
	task := &ztlCtxTask{next: nil, prev: nil, meta: m, cost: newCost}
	if zc.first == nil {
		zc.first = task
		zc.last = task

	// We have not found a task, therefore the new task is the first one
	task.next = zc.first
	zc.first.prev = task
	zc.first = task
}

func (zc *contextQueue) costMaxed(newCost int) bool {
	// If len(zc.seen) <= 1, the initial zettel is processed. In this case allow all
	// other zettel that are directly reachable, without taking the cost into account.
	// Of course, the limit ist still relevant.
	return (len(zc.seen) > 1 && zc.maxCost > 0 && newCost > zc.maxCost) || zc.hasLimit()
}

func (zc *contextQueue) addIDSet(ctx context.Context, newCost int, value string) {
	elems := meta.ListFromValue(value)
	refCost := referenceCost(newCost, len(elems))
	for _, val := range elems {
		zc.addID(ctx, refCost, val)

	return baseCost * numReferences / 8
}

func (zc *contextQueue) addSameTag(ctx context.Context, tag string, baseCost int) {
	tagMetas, found := zc.tagCost[tag]
	if !found {
		q := Parse(api.KeyTags + api.SearchOperatorHas + tag + " ORDER REVERSE " + api.KeyID)
		ml, err := zc.port.SelectMeta(ctx, nil, q)
		if err != nil {
			return
		}
		tagMetas = ml
		zc.tagCost[tag] = ml
	}
	cost := tagCost(baseCost, len(tagMetas))
	if zc.costMaxed(cost) {
		return
	}
	for _, m := range tagMetas {

		zc.addMeta(m, cost)

	}
}

func tagCost(baseCost, numTags int) int {
	if numTags < 8 {
		return baseCost + numTags/2
	}

		return m, task.cost
	}
	return nil, -1
}

func (zc *contextQueue) hasLimit() bool {
	limit := zc.limit
	return limit > 0 && len(zc.seen) >= limit
}

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

package query

import (
	"strconv"

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

// Parse the query specification and return a Query object.
func Parse(spec string) (q *Query) { return q.Parse(spec) }

		ps.skipSpace()
		return true
	}
	return false
}

const (
	actionSeparatorChar       = '|'
	existOperatorChar         = '?'
	searchOperatorNotChar     = '!'
	searchOperatorEqualChar   = '='
	searchOperatorHasChar     = ':'
	searchOperatorPrefixChar  = '['
	searchOperatorSuffixChar  = ']'
	searchOperatorMatchChar   = '~'
	searchOperatorLessChar    = '<'


	searchOperatorGreaterChar = '>'









)

func (ps *parserState) parse(q *Query) *Query {
	ps.skipSpace()
	if ps.mustStop() {
		return q
	}
	inp := ps.inp
	firstPos := inp.Pos
	zidSet := id.NewSet()
	for {
		pos := inp.Pos
		zid, found := ps.scanZid()
		if !found {
			inp.SetPos(pos)
			break
		}
		if !zidSet.Contains(zid) {
			zidSet.Zid(zid)
			q = createIfNeeded(q)
			q.zids = append(q.zids, zid)
		}
		ps.skipSpace()
		if ps.mustStop() {
			q.zids = nil
			break
		}
	}

	hasContext := false
	for {
		ps.skipSpace()
		if ps.mustStop() {
			break
		}
		pos := inp.Pos
		if ps.acceptSingleKw(api.ContextDirective) {
			if hasContext {
				inp.SetPos(pos)
				break
			}
			q = ps.parseContext(q, pos)
			hasContext = true
			continue
		}
		inp.SetPos(pos)
		if q == nil || len(q.zids) == 0 {
			break
		}
		if ps.acceptSingleKw(api.IdentDirective) {
			q.directives = append(q.directives, &IdentSpec{})
			continue
		}
		inp.SetPos(pos)
		if ps.acceptSingleKw(api.ItemsDirective) {
			q.directives = append(q.directives, &ItemsSpec{})
			continue
		}
		inp.SetPos(pos)
		if ps.acceptSingleKw(api.UnlinkedDirective) {
			q = ps.parseUnlinked(q)
			continue
		}
		inp.SetPos(pos)
		break
	}
	if q != nil && len(q.directives) == 0 {
		inp.SetPos(firstPos) // No directive -> restart at beginning
		q.zids = nil
	}

	for {
		ps.skipSpace()
		if ps.mustStop() {
			break
		}
		pos := inp.Pos
		if ps.acceptSingleKw(api.OrDirective) {
			q = createIfNeeded(q)
			if !q.terms[len(q.terms)-1].isEmpty() {
				q.terms = append(q.terms, conjTerms{})
			}
			continue
		}
		inp.SetPos(pos)
		if ps.acceptSingleKw(api.RandomDirective) {
			q = createIfNeeded(q)
			if len(q.order) == 0 {
				q.order = []sortOrder{{"", false}}
			}
			continue
		}
		inp.SetPos(pos)
		if ps.acceptKwArgs(api.PickDirective) {
			if s, ok := ps.parsePick(q); ok {
				q = s
				continue
			}
		}
		inp.SetPos(pos)
		if ps.acceptKwArgs(api.OrderDirective) {
			if s, ok := ps.parseOrder(q); ok {
				q = s
				continue
			}
		}
		inp.SetPos(pos)
		if ps.acceptKwArgs(api.OffsetDirective) {
			if s, ok := ps.parseOffset(q); ok {
				q = s
				continue
			}
		}
		inp.SetPos(pos)
		if ps.acceptKwArgs(api.LimitDirective) {
			if s, ok := ps.parseLimit(q); ok {
				q = s
				continue
			}
		}
		inp.SetPos(pos)
		if isActionSep(inp.Ch) {
			q = ps.parseActions(q)
			break
		}
		q = ps.parseText(q)
	}
	return q
}

func (ps *parserState) parseContext(q *Query, pos int) *Query {
	inp := ps.inp







	if q == nil || len(q.zids) == 0 {

		ps.skipSpace()
		if ps.mustStop() {
			inp.SetPos(pos)
			return q
		}
		zid, ok := ps.scanZid()
		if !ok {
			inp.SetPos(pos)
			return q
		}

		q = createIfNeeded(q)
		q.zids = append(q.zids, zid)

	}

	spec := &ContextSpec{}
	for {
		ps.skipSpace()
		if ps.mustStop() {
			break
		}
		pos = inp.Pos
		if ps.acceptSingleKw(api.BackwardDirective) {
			spec.Direction = ContextDirBackward
			continue
		}
		inp.SetPos(pos)
		if ps.acceptSingleKw(api.ForwardDirective) {
			spec.Direction = ContextDirForward
			continue
		}
		inp.SetPos(pos)
		if ps.acceptKwArgs(api.CostDirective) {
			if ps.parseCost(spec) {
				continue
			}
		}
		inp.SetPos(pos)
		if ps.acceptKwArgs(api.MaxDirective) {
			if ps.parseCount(spec) {
				continue
			}
		}

		inp.SetPos(pos)
		break
	}
	q.directives = append(q.directives, spec)
	return q
}
func (ps *parserState) parseCost(spec *ContextSpec) bool {
	num, ok := ps.scanPosInt()
	if !ok {
		return false
	}
	if spec.MaxCost == 0 || spec.MaxCost >= num {
		spec.MaxCost = num
	}
	return true
}
func (ps *parserState) parseCount(spec *ContextSpec) bool {
	num, ok := ps.scanPosInt()
	if !ok {
		return false
	}
	if spec.MaxCount == 0 || spec.MaxCount >= num {
		spec.MaxCount = num
	}
	return true
}

func (ps *parserState) parseUnlinked(q *Query) *Query {
	inp := ps.inp

	spec := &UnlinkedSpec{}
	for {
		ps.skipSpace()
		if ps.mustStop() {
			break
		}
		pos := inp.Pos
		if ps.acceptKwArgs(api.PhraseDirective) {
			if word := ps.scanWord(); len(word) > 0 {
				spec.words = append(spec.words, string(word))
				continue
			}
		}

		inp.SetPos(pos)
		break
	}
	q.directives = append(q.directives, spec)
	return q
}

func (ps *parserState) parsePick(q *Query) (*Query, bool) {
	num, ok := ps.scanPosInt()
	if !ok {
		return q, false
	}
	q = createIfNeeded(q)
	if q.pick == 0 || q.pick >= num {
		q.pick = num
	}
	return q, true
}

func (ps *parserState) parseOrder(q *Query) (*Query, bool) {
	reverse := false
	if ps.acceptKwArgs(api.ReverseDirective) {
		reverse = true
	}
	word := ps.scanWord()
	if len(word) == 0 {
		return q, false
	}
	if sWord := string(word); meta.KeyIsValid(sWord) {