Zettelstore

Copyright (c) 2020-2022 Detlef Stern

                          Licensed under the EUPL

Zettelstore is licensed under the European Union Public License, version 1.2 or
later (EUPL v. 1.2). The license is available in the official languages of the
EU. The English version is included here. Please see
https://joinup.ec.europa.eu/community/eupl/og_page/eupl for official

0.2

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

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

import (
	"net/url"

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

// ZettelNode is the root node of the abstract syntax tree.
// It is *not* part of the visitor pattern.
type ZettelNode struct {
	Meta    *meta.Meta     // Original metadata
	Content domain.Content // Original content
	Zid     id.Zid         // Zettel identification.
	InhMeta *meta.Meta     // Metadata of the zettel, with inherited values.
	Ast     *BlockListNode // Zettel abstract syntax tree is a sequence of block nodes.
	Syntax  string         // Syntax / parser that produced the Ast
}

// Node is the interface, all nodes must implement.
type Node interface {
	WalkChildren(v Visitor)
}

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


package ast

import "strings"



// Attributes store additional information about some node types.
type Attributes struct {
	Attrs map[string]string
}

// IsEmpty returns true if there are no attributes.

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


package ast_test

import (
	"testing"

	"zettelstore.de/z/ast"
)

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


package ast

// Definition of Block nodes.

// BlockListNode is a list of BlockNodes.
type BlockListNode struct {
	List []BlockNode

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


package ast

// Definitions of inline nodes.

// InlineListNode is a list of BlockNodes.
type InlineListNode struct {
	List []InlineNode

			inl = append(inl, &SpaceNode{Lexeme: " "})
		}
		inl = append(inl, &TextNode{Text: word})
	}
	return &InlineListNode{List: inl}
}

// WalkChildren walks down to the list.
func (iln *InlineListNode) WalkChildren(v Visitor) {
	for _, bn := range iln.List {
		Walk(v, bn)
	}
}

// IsEmpty returns true if the list has no elements.

}

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

// Constants for FormatCode
const (
	_               FormatKind = iota
	FormatEmph                 // Emphasized text.
	FormatStrong               // Strongly emphasized text.
	FormatInsert               // Inserted text.
	FormatDelete               // Deleted text.
	FormatSuper                // Superscripted text.
	FormatSub                  // SubscriptedText.
	FormatQuote                // Quoted text.
	FormatQuotation            // Quotation text.

	FormatSpan                 // Generic inline container.
	FormatMonospace            // Monospaced text.

)

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

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

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


package ast

// MaterialNode references the various types of zettel material.
type MaterialNode interface {
	Node
	materialNode()
}

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


package ast

import (
	"net/url"

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

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


package ast_test

import (
	"testing"

	"zettelstore.de/z/ast"
)

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


package ast

// Visitor is a visitor for walking the AST.
type Visitor interface {
	Visit(node Node) Visitor
}

// Walk traverses the AST.
func Walk(v Visitor, node Node) {
	if v = v.Visit(node); v == nil {
		return
	}

	// Implementation note:
	// It is much faster to use interface dispatching than to use a switch statement.
	// On my "cpu: Intel(R) Core(TM) i7-6820HQ CPU @ 2.70GHz", a switch statement
	// implementation tooks approx 940-980 ns/op. Interface dispatching is in the
	// range of 900-930 ns/op.
	node.WalkChildren(v)
	v.Visit(nil)
}

// WalkItemSlice traverses an item slice.
func WalkItemSlice(v Visitor, ins ItemSlice) {
	for _, in := range ins {

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

package ast_test

import (
	"testing"

	"zettelstore.de/z/ast"
)

func BenchmarkWalk(b *testing.B) {
	root := &ast.BlockListNode{
		List: []ast.BlockNode{
			&ast.HeadingNode{
				Inlines: ast.CreateInlineListNodeFromWords("A", "Simple", "Heading"),
			},
			&ast.ParaNode{
				Inlines: ast.CreateInlineListNodeFromWords("This", "is", "the", "introduction."),
			},
			&ast.NestedListNode{
				Kind: ast.NestedListUnordered,
				Items: []ast.ItemSlice{
					[]ast.ItemNode{
						&ast.ParaNode{
							Inlines: ast.CreateInlineListNodeFromWords("Item", "1"),
						},
					},
					[]ast.ItemNode{
						&ast.ParaNode{
							Inlines: ast.CreateInlineListNodeFromWords("Item", "2"),
						},
					},
				},
			},
			&ast.ParaNode{
				Inlines: ast.CreateInlineListNodeFromWords("This", "is", "some", "intermediate", "text."),
			},
			&ast.ParaNode{
				Inlines: ast.CreateInlineListNode(
					&ast.FormatNode{
						Kind: ast.FormatEmph,
						Attrs: &ast.Attributes{
							Attrs: map[string]string{
								"":      "class",
								"color": "green",
							},
						},
						Inlines: ast.CreateInlineListNodeFromWords("This", "is", "some", "emphasized", "text."),
					},
					&ast.SpaceNode{Lexeme: " "},
					&ast.LinkNode{
						Ref: &ast.Reference{
							Value: "http://zettelstore.de",
						},
						Inlines: ast.CreateInlineListNodeFromWords("URL", "text."),
						OnlyRef: false,
					},
				),
			},
		},
	}
	v := benchVisitor{}
	b.ResetTimer()
	for n := 0; n < b.N; n++ {
		ast.Walk(&v, root)
	}
}

type benchVisitor struct{}

func (bv *benchVisitor) Visit(ast.Node) ast.Visitor { return bv }

	// User is allowed to write zettel.
	CanWrite(user, oldMeta, newMeta *meta.Meta) bool

	// User is allowed to rename zettel
	CanRename(user, m *meta.Meta) bool

	// User is allowed to delete zettel.
	CanDelete(user, m *meta.Meta) bool

	// User is allowed to refresh box data.
	CanRefresh(user *meta.Meta) bool
}

}

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

const reqHash = jwt.HS512




// 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)
	claims := jwt.Claims{

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


package policy

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

func (ap *anonPolicy) CanRename(user, m *meta.Meta) bool {
	return ap.pre.CanRename(user, m) && ap.checkVisibility(m)
}

func (ap *anonPolicy) CanDelete(user, m *meta.Meta) bool {
	return ap.pre.CanDelete(user, m) && ap.checkVisibility(m)
}

func (ap *anonPolicy) CanRefresh(user *meta.Meta) bool {
	if ap.authConfig.GetExpertMode() || ap.authConfig.GetSimpleMode() {
		return true
	}
	return ap.pre.CanRefresh(user)
}

func (ap *anonPolicy) checkVisibility(m *meta.Meta) bool {
	if ap.authConfig.GetVisibility(m) == meta.VisibilityExpert {
		return ap.authConfig.GetExpertMode()
	}
	return true
}

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


package policy

import (
	"context"

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

	}
	user := pp.auth.GetUser(ctx)
	if pp.policy.CanDelete(user, meta) {
		return pp.box.DeleteZettel(ctx, zid)
	}
	return box.NewErrNotAllowed("Delete", user, zid)
}

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

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


package policy

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

type defaultPolicy struct {
	manager auth.AuthzManager
}

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

func (*defaultPolicy) CanRefresh(user *meta.Meta) bool { return user != nil }

func (d *defaultPolicy) canChange(user, m *meta.Meta) bool {
	metaRo, ok := m.Get(api.KeyReadOnly)
	if !ok {
		return true
	}
	if user == nil {

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


package policy

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

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

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

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

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

	}
	if o.userIsOwner(user) {
		return true
	}
	if !o.userCanRead(user, oldMeta, vis) {
		return false
	}
	if _, ok := oldMeta.Get(api.KeyUserID); ok {
		// Here we know, that user.Zid == newMeta.Zid (because of userCanRead) and
		// user.Zid == newMeta.Zid (because oldMeta.Zid == newMeta.Zid)
		for _, key := range noChangeUser {
			if oldMeta.GetDefault(key, "") != newMeta.GetDefault(key, "") {
				return false
			}
		}

		return false
	}
	if res, ok := o.checkVisibility(user, o.authConfig.GetVisibility(m)); ok {
		return res
	}
	return o.userIsOwner(user)
}

func (o *ownerPolicy) CanRefresh(user *meta.Meta) bool {
	switch userRole := o.manager.GetUserRole(user); userRole {
	case meta.UserRoleUnknown:
		return o.authConfig.GetSimpleMode()
	case meta.UserRoleCreator:
		return o.authConfig.GetExpertMode() || o.authConfig.GetSimpleMode()
	}
	return true
}

func (o *ownerPolicy) checkVisibility(user *meta.Meta, vis meta.Visibility) (bool, bool) {
	if vis == meta.VisibilityExpert {
		return o.userIsOwner(user) && o.authConfig.GetExpertMode(), true
	}
	return false, false
}

func (p *prePolicy) CanRename(user, m *meta.Meta) bool {
	return m != nil && p.post.CanRename(user, m)
}

func (p *prePolicy) CanDelete(user, m *meta.Meta) bool {
	return m != nil && p.post.CanDelete(user, m)
}

func (p *prePolicy) CanRefresh(user *meta.Meta) bool {
	return p.post.CanRefresh(user)
}

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


package policy

import (
	"fmt"
	"testing"

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

func TestPolicies(t *testing.T) {
	t.Parallel()
	testScene := []struct {
		readonly bool
		withAuth bool
		expert   bool
		simple   bool
	}{
		{true, true, true, true},
		{true, true, true, false},
		{true, true, false, true},
		{true, true, false, false},
		{true, false, true, true},
		{true, false, true, false},
		{true, false, false, true},
		{true, false, false, false},
		{false, true, true, true},
		{false, true, true, false},
		{false, true, false, true},
		{false, true, false, false},
		{false, false, true, true},
		{false, false, true, false},
		{false, false, false, true},
		{false, false, false, false},
	}
	for _, ts := range testScene {
		pol := newPolicy(
			&testAuthzManager{readOnly: ts.readonly, withAuth: ts.withAuth},


			&authConfig{simple: ts.simple, expert: ts.expert},
		)
		name := fmt.Sprintf("readonly=%v/withauth=%v/expert=%v/simple=%v",
			ts.readonly, ts.withAuth, ts.expert, ts.simple)
		t.Run(name, func(tt *testing.T) {
			testCreate(tt, pol, ts.withAuth, ts.readonly)
			testRead(tt, pol, ts.withAuth, ts.expert)
			testWrite(tt, pol, ts.withAuth, ts.readonly, ts.expert)
			testRename(tt, pol, ts.withAuth, ts.readonly, ts.expert)
			testDelete(tt, pol, ts.withAuth, ts.readonly, ts.expert)
			testRefresh(tt, pol, ts.withAuth, ts.expert, ts.simple)
		})
	}
}

type testAuthzManager struct {
	readOnly bool
	withAuth bool

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

type authConfig struct{ simple, expert bool }

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

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

			got := pol.CanDelete(tc.user, tc.meta)
			if tc.exp != got {
				tt.Errorf("exp=%v, but got=%v", tc.exp, got)
			}
		})
	}
}

func testRefresh(t *testing.T, pol auth.Policy, withAuth, expert, simple bool) {
	t.Helper()
	testCases := []struct {
		user *meta.Meta
		exp  bool
	}{
		{newAnon(), (!withAuth && expert) || simple},
		{newCreator(), !withAuth || expert || simple},
		{newReader(), true},
		{newWriter(), true},
		{newOwner(), true},
		{newOwner2(), true},
	}
	for _, tc := range testCases {
		t.Run("Refresh", func(tt *testing.T) {
			got := pol.CanRefresh(tc.user)
			if tc.exp != got {
				tt.Errorf("exp=%v, but got=%v", tc.exp, got)
			}
		})
	}
}

const (
	creatorZid = id.Zid(1013)
	readerZid  = id.Zid(1013)
	writerZid  = id.Zid(1015)
	ownerZid   = id.Zid(1017)
	owner2Zid  = id.Zid(1019)
	zettelZid  = id.Zid(1021)
	visZid     = id.Zid(1023)
	userZid    = id.Zid(1025)
)

func newAnon() *meta.Meta { return nil }
func newCreator() *meta.Meta {
	user := meta.New(creatorZid)
	user.Set(api.KeyTitle, "Creator")
	user.Set(api.KeyUserID, "ceator")
	user.Set(api.KeyUserRole, api.ValueUserRoleCreator)
	return user
}
func newReader() *meta.Meta {
	user := meta.New(readerZid)
	user.Set(api.KeyTitle, "Reader")
	user.Set(api.KeyUserID, "reader")
	user.Set(api.KeyUserRole, api.ValueUserRoleReader)
	return user
}
func newWriter() *meta.Meta {
	user := meta.New(writerZid)
	user.Set(api.KeyTitle, "Writer")
	user.Set(api.KeyUserID, "writer")
	user.Set(api.KeyUserRole, api.ValueUserRoleWriter)
	return user
}
func newOwner() *meta.Meta {
	user := meta.New(ownerZid)
	user.Set(api.KeyTitle, "Owner")
	user.Set(api.KeyUserID, "owner")
	user.Set(api.KeyUserRole, api.ValueUserRoleOwner)
	return user
}
func newOwner2() *meta.Meta {
	user := meta.New(owner2Zid)
	user.Set(api.KeyTitle, "Owner 2")
	user.Set(api.KeyUserID, "owner-2")
	user.Set(api.KeyUserRole, api.ValueUserRoleOwner)
	return user
}
func newZettel() *meta.Meta {
	m := meta.New(zettelZid)
	m.Set(api.KeyTitle, "Any Zettel")
	return m

	m.Set(api.KeyTitle, "Owner r/o Zettel")
	m.Set(api.KeyReadOnly, api.ValueUserRoleOwner)
	return m
}
func newUserZettel() *meta.Meta {
	m := meta.New(userZid)
	m.Set(api.KeyTitle, "Any User")
	m.Set(api.KeyUserID, "any")
	return m
}

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


package policy

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

type roPolicy struct{}

func (*roPolicy) CanCreate(_, _ *meta.Meta) bool   { return false }
func (*roPolicy) CanRead(_, _ *meta.Meta) bool     { return true }
func (*roPolicy) CanWrite(_, _, _ *meta.Meta) bool { return false }
func (*roPolicy) CanRename(_, _ *meta.Meta) bool   { return false }
func (*roPolicy) CanDelete(_, _ *meta.Meta) bool   { return false }
func (*roPolicy) CanRefresh(user *meta.Meta) bool  { return user != nil }

// 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

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

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

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

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

// StartStopper performs simple lifecycle management.
type StartStopper interface {
	// Start the box. Now all other functions of the box are allowed.
	// Starting an already started box is not allowed.
	Start(ctx context.Context) error

	// Stop the started box. Now only the Start() function is allowed.
	Stop(ctx context.Context)
}

// Refresher allow to refresh their internal data.
type Refresher interface {
	// Refresh the box data.
	Refresh(context.Context)
}

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

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

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

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

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

	// 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 {
	// ReadOnly indicates that boxes cannot be modified.
	ReadOnly bool

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

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

type compBox struct {
	log      *logger.Logger
	number   int
	enricher box.Enricher
}

var myConfig *meta.Meta
var myZettel = map[id.Zid]struct {
	meta    func(id.Zid) *meta.Meta
	content func(*meta.Meta) []byte
}{
	id.MustParse(api.ZidVersion):              {genVersionBuildM, genVersionBuildC},
	id.MustParse(api.ZidHost):                 {genVersionHostM, genVersionHostC},
	id.MustParse(api.ZidOperatingSystem):      {genVersionOSM, genVersionOSC},
	id.MustParse(api.ZidLog):                  {genLogM, genLogC},
	id.MustParse(api.ZidBoxManager):           {genManagerM, genManagerC},
	id.MustParse(api.ZidMetadataKey):          {genKeysM, genKeysC},
	id.MustParse(api.ZidParser):               {genParserM, genParserC},
	id.MustParse(api.ZidStartupConfiguration): {genConfigZettelM, genConfigZettelC},
}

// Get returns the one program box.
func getCompBox(boxNumber int, mf box.Enricher) box.ManagedBox {
	return &compBox{
		log: kernel.Main.GetLogger(kernel.BoxService).Clone().
			Str("box", "comp").Int("boxnum", int64(boxNumber)).Child(),
		number:   boxNumber,
		enricher: mf,
	}
}

// Setup remembers important values.
func Setup(cfg *meta.Meta) { myConfig = cfg.Clone() }

func (*compBox) Location() string { return "" }

func (*compBox) CanCreateZettel(context.Context) bool { return false }

func (cb *compBox) CreateZettel(context.Context, domain.Zettel) (id.Zid, error) {
	cb.log.Trace().Err(box.ErrReadOnly).Msg("CreateZettel")
	return id.Invalid, box.ErrReadOnly
}

func (cb *compBox) GetZettel(_ context.Context, zid id.Zid) (domain.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("GetMeta/Content")
				return domain.Zettel{
					Meta:    m,
					Content: domain.NewContent(genContent(m)),
				}, nil
			}
			cb.log.Trace().Msg("GetMeta/NoContent")
			return domain.Zettel{Meta: m}, nil
		}
	}
	cb.log.Trace().Err(box.ErrNotFound).Msg("GetZettel/Err")
	return domain.Zettel{}, box.ErrNotFound
}

func (cb *compBox) GetMeta(_ context.Context, zid id.Zid) (*meta.Meta, error) {
	if gen, ok := myZettel[zid]; ok {
		if genMeta := gen.meta; genMeta != nil {
			if m := genMeta(zid); m != nil {
				updateMeta(m)
				cb.log.Trace().Msg("GetMeta")
				return m, nil
			}
		}
	}
	cb.log.Trace().Err(box.ErrNotFound).Msg("GetMeta/Err")
	return nil, box.ErrNotFound
}

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

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

func (*compBox) CanUpdateZettel(context.Context, domain.Zettel) bool { return false }

func (cb *compBox) UpdateZettel(context.Context, domain.Zettel) error {
	cb.log.Trace().Err(box.ErrReadOnly).Msg("UpdateZettel")
	return box.ErrReadOnly
}

func (*compBox) AllowRenameZettel(_ context.Context, zid id.Zid) bool {
	_, ok := myZettel[zid]
	return !ok
}

func (cb *compBox) RenameZettel(_ context.Context, curZid, _ id.Zid) error {
	err := box.ErrNotFound
	if _, ok := myZettel[curZid]; ok {
		err = box.ErrReadOnly
	}
	cb.log.Trace().Err(err).Msg("RenameZettel")
	return err
}

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

func (cb *compBox) DeleteZettel(_ context.Context, zid id.Zid) error {
	err := box.ErrNotFound
	if _, ok := myZettel[zid]; ok {
		err = box.ErrReadOnly
	}
	cb.log.Trace().Err(err).Msg("DeleteZettel")
	return err
}

func (cb *compBox) ReadStats(st *box.ManagedBoxStats) {
	st.ReadOnly = true
	st.Zettel = len(myZettel)
	cb.log.Trace().Int("zettel", int64(st.Zettel)).Msg("ReadStats")
}

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

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


package compbox

import (
	"bytes"

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

	m.Set(api.KeyTitle, "Zettelstore Startup Configuration")
	m.Set(api.KeyVisibility, api.ValueVisibilityExpert)
	return m
}

func genConfigZettelC(*meta.Meta) []byte {
	var buf bytes.Buffer
	for i, p := range myConfig.Pairs() {
		if i > 0 {
			buf.WriteByte('\n')
		}
		buf.WriteString("; ''")
		buf.WriteString(p.Key)
		buf.WriteString("''")
		if p.Value != "" {

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


package compbox

import (
	"bytes"
	"fmt"

	"zettelstore.de/c/api"

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

package compbox

import (
	"bytes"

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

func genLogM(zid id.Zid) *meta.Meta {
	m := meta.New(zid)
	m.Set(api.KeyTitle, "Zettelstore Log")
	m.Set(api.KeySyntax, api.ValueSyntaxText)
	return m
}

func genLogC(*meta.Meta) []byte {
	const tsFormat = "2006-01-02 15:04:05.999999"
	entries := kernel.Main.RetrieveLogEntries()
	var buf bytes.Buffer
	for _, entry := range entries {
		ts := entry.TS.Format(tsFormat)
		buf.WriteString(ts)
		for j := len(ts); j < len(tsFormat); j++ {
			buf.WriteByte('0')
		}
		buf.WriteByte(' ')
		buf.WriteString(entry.Level.Format())
		buf.WriteByte(' ')
		buf.WriteString(entry.Prefix)
		buf.WriteByte(' ')
		buf.WriteString(entry.Message)
		buf.WriteByte('\n')
	}
	return buf.Bytes()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021 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 (
	"bytes"
	"fmt"

	"zettelstore.de/c/api"

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

package compbox

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

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

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

func genParserC(*meta.Meta) []byte {
	var buf bytes.Buffer
	buf.WriteString("|=Syntax<|=Alt. Value(s):|=Text Parser?:|=Image Format?:\n")
	syntaxes := parser.GetSyntaxes()
	sort.Strings(syntaxes)
	for _, syntax := range syntaxes {
		info := parser.Get(syntax)
		if info.Name != syntax {
			continue
		}
		altNames := info.AltNames
		sort.Strings(altNames)
		fmt.Fprintf(
			&buf, "|%v|%v|%v|%v\n",
			syntax, strings.Join(altNames, ", "), info.IsTextParser, info.IsImageFormat)
	}
	return buf.Bytes()
}

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


package compbox

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

func getVersionMeta(zid id.Zid, title string) *meta.Meta {
	m := meta.New(zid)
	m.Set(api.KeyTitle, title)
	m.Set(api.KeyVisibility, api.ValueVisibilityExpert)
	return m
}

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

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

{{/WithUser}}
<div class="zs-dropdown">
<button>Lists</button>
<nav class="zs-dropdown-content">
<a href="{{{ListZettelURL}}}">List Zettel</a>
<a href="{{{ListRolesURL}}}">List Roles</a>
<a href="{{{ListTagsURL}}}">List Tags</a>
{{#CanRefresh}}
<a href="{{{RefreshURL}}}">Refresh</a>
{{/CanRefresh}}
</nav>
</div>
{{#HasNewZettelLinks}}
<div class="zs-dropdown">
<button>New</button>
<nav class="zs-dropdown-content">
{{#NewZettelLinks}}

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

func init() {
	manager.Register(
		" const",
		func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
			return &constBox{
				log: kernel.Main.GetLogger(kernel.BoxService).Clone().
					Str("box", "const").Int("boxnum", int64(cdata.Number)).Child(),
				number:   cdata.Number,
				zettel:   constZettelMap,
				enricher: cdata.Enricher,
			}, nil
		})
}

type constHeader map[string]string

type constZettel struct {
	header  constHeader
	content domain.Content
}

type constBox struct {
	log      *logger.Logger
	number   int
	zettel   map[id.Zid]constZettel
	enricher box.Enricher
}

func (*constBox) Location() string { return "const:" }

func (*constBox) CanCreateZettel(context.Context) bool { return false }

func (cb *constBox) CreateZettel(context.Context, domain.Zettel) (id.Zid, error) {
	cb.log.Trace().Err(box.ErrReadOnly).Msg("CreateZettel")
	return id.Invalid, box.ErrReadOnly
}

func (cb *constBox) GetZettel(_ context.Context, zid id.Zid) (domain.Zettel, error) {
	if z, ok := cb.zettel[zid]; ok {
		cb.log.Trace().Msg("GetZettel")
		return domain.Zettel{Meta: meta.NewWithData(zid, z.header), Content: z.content}, nil
	}
	cb.log.Trace().Err(box.ErrNotFound).Msg("GetZettel")
	return domain.Zettel{}, box.ErrNotFound
}

func (cb *constBox) GetMeta(_ context.Context, zid id.Zid) (*meta.Meta, error) {
	if z, ok := cb.zettel[zid]; ok {
		cb.log.Trace().Msg("GetMeta")
		return meta.NewWithData(zid, z.header), nil
	}
	cb.log.Trace().Err(box.ErrNotFound).Msg("GetMeta")
	return nil, box.ErrNotFound
}

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

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

func (*constBox) CanUpdateZettel(context.Context, domain.Zettel) bool { return false }

func (cb *constBox) UpdateZettel(context.Context, domain.Zettel) error {
	cb.log.Trace().Err(box.ErrReadOnly).Msg("UpdateZettel")
	return box.ErrReadOnly
}

func (cb *constBox) AllowRenameZettel(_ context.Context, zid id.Zid) bool {
	_, ok := cb.zettel[zid]
	return !ok
}

func (cb *constBox) RenameZettel(_ context.Context, curZid, _ id.Zid) error {
	err := box.ErrNotFound
	if _, ok := cb.zettel[curZid]; ok {
		err = box.ErrReadOnly
	}
	cb.log.Trace().Err(err).Msg("RenameZettel")
	return err
}

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

func (cb *constBox) DeleteZettel(_ context.Context, zid id.Zid) error {
	err := box.ErrNotFound
	if _, ok := cb.zettel[zid]; ok {
		err = box.ErrReadOnly
	}
	cb.log.Trace().Err(err).Msg("DeleteZettel")
	return err
}

func (cb *constBox) ReadStats(st *box.ManagedBoxStats) {
	st.ReadOnly = true
	st.Zettel = len(cb.zettel)
	cb.log.Trace().Int("zettel", int64(st.Zettel)).Msg("ReadStats")
}

const syntaxTemplate = "mustache"

var constZettelMap = map[id.Zid]constZettel{
	id.ConfigurationZid: {
		constHeader{

	id.MustParse(api.ZidAuthors): {
		constHeader{
			api.KeyTitle:      "Zettelstore Contributors",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     api.ValueSyntaxZmk,
			api.KeyLang:       api.ValueLangEN,
			api.KeyReadOnly:   api.ValueTrue,
			api.KeyVisibility: api.ValueVisibilityLogin,
		},
		domain.NewContent(contentContributors)},
	id.MustParse(api.ZidDependencies): {
		constHeader{
			api.KeyTitle:      "Zettelstore Dependencies",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     api.ValueSyntaxZmk,
			api.KeyLang:       api.ValueLangEN,
			api.KeyReadOnly:   api.ValueTrue,
			api.KeyVisibility: api.ValueVisibilityLogin,
		},
		domain.NewContent(contentDependencies)},
	id.BaseTemplateZid: {
		constHeader{
			api.KeyTitle:      "Zettelstore Base HTML Template",
			api.KeyRole:       api.ValueRoleConfiguration,
			api.KeySyntax:     syntaxTemplate,

			api.KeySyntax:     api.ValueSyntaxZmk,
			api.KeyVisibility: api.ValueVisibilityCreator,
		},
		domain.NewContent(nil)},
	id.MustParse(api.ZidTemplateNewUser): {
		constHeader{
			api.KeyTitle:                       "New User",
			api.KeyRole:                        api.ValueRoleConfiguration,
			api.KeySyntax:                      api.ValueSyntaxNone,
			meta.NewPrefix + api.KeyCredential: "",
			meta.NewPrefix + api.KeyUserID:     "",
			meta.NewPrefix + api.KeyUserRole:   api.ValueUserRoleReader,
			api.KeyVisibility:                  api.ValueVisibilityOwner,
		},
		domain.NewContent(nil)},

<ul>
{{#Incoming}}
<li><a href="{{{URL}}}">{{Text}}</a></li>
{{/Incoming}}
</ul>
</div>
{{/HasIncoming}}
{{#HasUselessFiles}}
<div class="zs-warning">
<h2>Warning!</h2>
<p>Deleting this zettel will also delete the following files, so that they will not be interpreted as content for this zettel.</p>
<ul>
{{#UselessFiles}}
<li>{{{.}}}</li>
{{/UselessFiles}}
</ul>
</div>
{{/HasUselessFiles}}
<dl>
{{#MetaPairs}}
<dt>{{Key}}:</dt><dd>{{Value}}</dd>
{{/MetaPairs}}
</dl>
<form method="POST">
<input class="zs-button" type="submit" value="Delete">
</form>
</article>
{{end}}

Zettelstore is made with the help of other software and other artifacts.
Thank you very much!

This zettel lists all of them, together with their licenses.

=== Go runtime and associated libraries
; License
: BSD 3-Clause "New" or "Revised" License
```
Copyright (c) 2009 The Go Authors. All rights reserved.

<article>
<header>
<h1>Information for Zettel {{Zid}}</h1>
<a href="{{{WebURL}}}">Web</a>
&#183; <a href="{{{ContextURL}}}">Context</a>
{{#CanWrite}} &#183; <a href="{{{EditURL}}}">Edit</a>{{/CanWrite}}
{{#CanFolge}} &#183; <a href="{{{FolgeURL}}}">Folge</a>{{/CanFolge}}
{{#CanCopy}} &#183; <a href="{{{CopyURL}}}">Copy</a>{{/CanCopy}}
{{#CanRename}}&#183; <a href="{{{RenameURL}}}">Rename</a>{{/CanRename}}
{{#CanDelete}}&#183; <a href="{{{DeleteURL}}}">Delete</a>{{/CanDelete}}
</header>
<h2>Interpreted Metadata</h2>
<table>{{#MetaData}}<tr><td>{{Key}}</td><td>{{{Value}}}</td></tr>{{/MetaData}}</table>

<h2>References</h2>
{{#HasLocLinks}}
<h3>Local</h3>
<ul>
{{#LocLinks}}
{{#Valid}}<li><a href="{{{Zid}}}">{{Zid}}</a></li>{{/Valid}}
{{^Valid}}<li>{{Zid}}</li>{{/Valid}}
{{/LocLinks}}
</ul>
{{/HasLocLinks}}
{{#HasExtLinks}}
<h3>External</h3>
<ul>
{{#ExtLinks}}
<li><a href="{{{.}}}"{{{ExtNewWindow}}}>{{.}}</a></li>
{{/ExtLinks}}
</ul>
{{/HasExtLinks}}
<h3>Unlinked</h3>
<ul>
{{#UnLinks}}
<li><a href="{{{URL}}}">{{{Text}}}</a></li>
{{/UnLinks}}
</ul>
<form>
<label for="phrase">Search Phrase</label>
<input class="zs-input" type="text" id="phrase" name="{{QueryKeyPhrase}}" placeholder="Phrase.." value="{{UnLinksPhrase}}">
</form>
<h2>Parts and encodings</h2>
<table>
{{#EvalMatrix}}
<tr>
<th>{{Header}}</th>
{{#Elements}}<td><a href="{{{URL}}}">{{Text}}</td>
{{/Elements}}

<article>
<header>
<h1>Rename Zettel {{Zid}}</h1>
</header>
<p>Do you really want to rename this zettel?</p>
{{#HasIncoming}}
<div class="zs-warning">
<h2>Warning!</h2>
<p>If you rename this zettel, incoming references from the following zettel will become invalid.</p>
<ul>
{{#Incoming}}
<li><a href="{{{URL}}}">{{Text}}</a></li>
{{/Incoming}}
</ul>
</div>
{{/HasIncoming}}
{{#HasUselessFiles}}
<div class="zs-warning">
<h2>Warning!</h2>
<p>Renaming this zettel will also delete the following files, so that they will not be interpreted as content for a zettel with identifier {{Zid}}.</p>
<ul>
{{#UselessFiles}}
<li>{{{.}}}</li>
{{/UselessFiles}}
</ul>
</div>
{{/HasUselessFiles}}
<form method="POST">
<div>
<label for="newid">New zettel id</label>
<input class="zs-input" type="text" id="newzid" name="newzid" placeholder="ZID.." value="{{Zid}}" autofocus>
</div>
<input type="hidden" id="curzid" name="curzid" value="{{Zid}}">
<input class="zs-button" type="submit" value="Rename">

{{/FolgeLinks}}
</ul>
</details>
</nav>
{{/HasFolgeLinks}}
{{#HasBackLinks}}
<nav>
<details open>
<summary>Incoming</summary>
<ul>
{{#BackLinks}}
<li><a href="{{{URL}}}">{{Text}}</a></li>
{{/BackLinks}}
</ul>
</details>
</nav>
{{/HasBackLinks}}

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

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

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

	"sync"


	"zettelstore.de/c/api"
	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager"
	"zettelstore.de/z/box/notify"

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

func init() {
	manager.Register("dir", func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
		var log *logger.Logger
		if krnl := kernel.Main; krnl != nil {
			log = krnl.GetLogger(kernel.BoxService).Clone().Str("box", "dir").Int("boxnum", int64(cdata.Number)).Child()
		}
		path := getDirPath(u)
		if _, err := os.Stat(path); errors.Is(err, os.ErrNotExist) {
			return nil, err
		}

		dp := dirBox{
			log:        log,
			number:     cdata.Number,
			location:   u.String(),
			readonly:   getQueryBool(u, "readonly"),
			cdata:      *cdata,
			dir:        path,

			notifySpec: getDirSrvInfo(log, u.Query().Get("type")),
			fSrvs:      makePrime(uint32(getQueryInt(u, "worker", 1, 7, 1499))),
		}
		return &dp, nil
	})
}

func makePrime(n uint32) uint32 {
	for !isPrime(n) {
		n++
	}
	return n
}

func isPrime(n uint32) bool {
	if n == 0 {
		return false
	}
	if n <= 3 {
		return true
	}
	if n%2 == 0 {
		return false
	}
	for i := uint32(3); i*i <= n; i += 2 {
		if n%i == 0 {
			return false
		}
	}
	return true
}

type notifyTypeSpec int

const (
	_ notifyTypeSpec = iota
	dirNotifyAny
	dirNotifySimple
	dirNotifyFS
)

func getDirSrvInfo(log *logger.Logger, notifyType string) notifyTypeSpec {
	for count := 0; count < 2; count++ {
		switch notifyType {
		case kernel.BoxDirTypeNotify:
			return dirNotifyFS
		case kernel.BoxDirTypeSimple:
			return dirNotifySimple
		default:
			notifyType = kernel.Main.GetConfig(kernel.BoxService, kernel.BoxDefaultDirType).(string)
		}
	}
	log.Error().Str("notifyType", notifyType).Msg("Unable to set notify type, using a default")
	return dirNotifySimple
}

func getDirPath(u *url.URL) string {
	if u.Opaque != "" {
		return filepath.Clean(u.Opaque)
	}
	return filepath.Clean(u.Path)
}

		return max
	}
	return iVal
}

// dirBox uses a directory to store zettel as files.
type dirBox struct {
	log        *logger.Logger
	number     int
	location   string
	readonly   bool
	cdata      manager.ConnectData
	dir        string

	notifySpec notifyTypeSpec
	dirSrv     *notify.DirService

	fSrvs      uint32
	fCmds      []chan fileCmd
	mxCmds     sync.RWMutex
}

func (dp *dirBox) Location() string {
	return dp.location
}

func (dp *dirBox) Start(context.Context) error {
	dp.mxCmds.Lock()
	defer dp.mxCmds.Unlock()
	dp.fCmds = make([]chan fileCmd, 0, dp.fSrvs)
	for i := uint32(0); i < dp.fSrvs; i++ {
		cc := make(chan fileCmd)
		go fileService(i, dp.log.Clone().Str("sub", "file").Uint("fn", uint64(i)).Child(), dp.dir, cc)
		dp.fCmds = append(dp.fCmds, cc)
	}

	var notifier notify.Notifier
	var err error
	switch dp.notifySpec {
	case dirNotifySimple:
		notifier, err = notify.NewSimpleDirNotifier(dp.log.Clone().Str("notify", "simple").Child(), dp.dir)
	default:
		notifier, err = notify.NewFSDirNotifier(dp.log.Clone().Str("notify", "fs").Child(), dp.dir)
	}
	if err != nil {
		dp.log.Fatal().Err(err).Msg("Unable to create directory supervisor")
		dp.stopFileServices()
		return err
	}
	dp.dirSrv = notify.NewDirService(
		dp.log.Clone().Str("sub", "dirsrv").Child(),
		notifier,
		dp.cdata.Notify,
	)
	dp.dirSrv.Start()
	return nil
}

func (dp *dirBox) Refresh(_ context.Context) {
	dp.dirSrv.Refresh()
	dp.log.Trace().Msg("Refresh")
}

func (dp *dirBox) Stop(_ context.Context) {
	dirSrv := dp.dirSrv
	dp.dirSrv = nil
	if dirSrv != nil {
		dirSrv.Stop()
	}
	dp.stopFileServices()
}

func (dp *dirBox) stopFileServices() {
	for _, c := range dp.fCmds {
		close(c)
	}

}

func (dp *dirBox) notifyChanged(reason box.UpdateReason, zid id.Zid) {

	if chci := dp.cdata.Notify; chci != nil {
		dp.log.Trace().Zid(zid).Uint("reason", uint64(reason)).Msg("notifyChanged")
		chci <- box.UpdateInfo{Reason: reason, Zid: zid}

	}
}

func (dp *dirBox) getFileChan(zid id.Zid) chan fileCmd {
	// Based on https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function
	sum := 2166136261 ^ uint32(zid)
	sum *= 16777619
	sum ^= uint32(zid >> 32)
	sum *= 16777619

	dp.mxCmds.RLock()
	defer dp.mxCmds.RUnlock()
	return dp.fCmds[sum%dp.fSrvs]
}

func (dp *dirBox) CanCreateZettel(_ context.Context) bool {
	return !dp.readonly
}

func (dp *dirBox) CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error) {
	if dp.readonly {
		return id.Invalid, box.ErrReadOnly
	}

	newZid, err := dp.dirSrv.SetNewDirEntry()
	if err != nil {
		return id.Invalid, err
	}
	meta := zettel.Meta
	meta.Zid = newZid
	entry := notify.DirEntry{Zid: newZid}
	dp.updateEntryFromMetaContent(&entry, meta, zettel.Content)

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

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

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

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


	for _, entry := range entries {
		handle(entry.Zid)
	}
	return nil
}

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


	// The following loop could be parallelized if needed for performance.
	for _, entry := range entries {
		m, err := dp.srvGetMeta(ctx, entry, entry.Zid)
		if err != nil {
			dp.log.Trace().Err(err).Msg("ApplyMeta/getMeta")
			return err
		}
		dp.cleanupMeta(m)
		dp.cdata.Enricher.Enrich(ctx, m, dp.number)
		handle(m)
	}
	return nil
}

func (dp *dirBox) CanUpdateZettel(context.Context, domain.Zettel) bool {
	return !dp.readonly
}

func (dp *dirBox) UpdateZettel(ctx context.Context, zettel domain.Zettel) error {
	if dp.readonly {
		return box.ErrReadOnly
	}

	meta := zettel.Meta
	zid := meta.Zid
	if !zid.IsValid() {
		return &box.ErrInvalidID{Zid: zid}
	}
	entry := dp.dirSrv.GetDirEntry(zid)



	if !entry.IsValid() {
		// Existing zettel, but new in this box.
		entry = &notify.DirEntry{Zid: zid}
	}
	dp.updateEntryFromMetaContent(entry, meta, zettel.Content)




	dp.dirSrv.UpdateDirEntry(entry)


	err := dp.srvSetZettel(ctx, entry, zettel)
	if err == nil {
		dp.notifyChanged(box.OnUpdate, zid)
	}
	dp.log.Trace().Zid(zid).Err(err).Msg("UpdateZettel")
	return err
}










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


















	entry.SetupFromMetaContent(m, content, dp.cdata.Config.GetZettelFileSyntax)





}

func (dp *dirBox) AllowRenameZettel(context.Context, id.Zid) bool {
	return !dp.readonly
}

func (dp *dirBox) RenameZettel(ctx context.Context, curZid, newZid id.Zid) error {
	if curZid == newZid {
		return nil
	}
	curEntry := dp.dirSrv.GetDirEntry(curZid)
	if !curEntry.IsValid() {
		return box.ErrNotFound
	}
	if dp.readonly {
		return box.ErrReadOnly
	}

	// Check whether zettel with new ID already exists in this box.
	if _, err := dp.doGetMeta(ctx, newZid); err == nil {
		return &box.ErrInvalidID{Zid: newZid}
	}

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








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

func (dp *dirBox) CanDeleteZettel(_ context.Context, zid id.Zid) bool {
	if dp.readonly {
		return false
	}
	entry := dp.dirSrv.GetDirEntry(zid)
	return entry.IsValid()
}

func (dp *dirBox) DeleteZettel(ctx context.Context, zid id.Zid) error {
	if dp.readonly {
		return box.ErrReadOnly
	}

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

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

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

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

package dirbox

import "testing"

func TestIsPrime(t *testing.T) {
	testcases := []struct {
		n   uint32
		exp bool
	}{
		{0, false}, {1, true}, {2, true}, {3, true}, {4, false}, {5, true},
		{6, false}, {7, true}, {8, false}, {9, false}, {10, false},
		{11, true}, {12, false}, {13, true}, {14, false}, {15, false},
		{17, true}, {19, true}, {21, false}, {23, true}, {25, false},
		{27, false}, {29, true}, {31, true}, {33, false}, {35, false},
	}
	for _, tc := range testcases {
		got := isPrime(tc.n)
		if got != tc.exp {
			t.Errorf("isPrime(%d)=%v, but got %v", tc.n, tc.exp, got)
		}
	}
}

func TestMakePrime(t *testing.T) {
	for i := uint32(0); i < 1500; i++ {
		np := makePrime(i)
		if np < i {
			t.Errorf("makePrime(%d) < %d", i, np)
			continue
		}
		if !isPrime(np) {
			t.Errorf("makePrime(%d) == %d is not prime", i, np)
			continue
		}
		if isPrime(i) && i != np {
			t.Errorf("%d is already prime, but got %d as next prime", i, np)
			continue
		}
	}
}

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


package dirbox

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

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

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

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

type fileCmd interface {
	run(*logger.Logger, string)
}

const serviceTimeout = 5 * time.Second // must be shorter than the web servers timeout values for reading+writing.

// COMMAND: srvGetMeta ----------------------------------------
//
// Retrieves the meta data from a zettel.

func (dp *dirBox) srvGetMeta(ctx context.Context, entry *notify.DirEntry, zid id.Zid) (*meta.Meta, error) {
	rc := make(chan resGetMeta, 1)
	dp.getFileChan(zid) <- &fileGetMeta{entry, rc}
	ctx, cancel := context.WithTimeout(ctx, serviceTimeout)
	defer cancel()
	select {
	case res := <-rc:

		return res.meta, res.err
	case <-ctx.Done():
		return nil, ctx.Err()
	}
}

type fileGetMeta struct {
	entry *notify.DirEntry
	rc    chan<- resGetMeta
}
type resGetMeta struct {
	meta *meta.Meta
	err  error
}

func (cmd *fileGetMeta) run(log *logger.Logger, dirPath string) {

	var m *meta.Meta
	var err error

	entry := cmd.entry
	zid := entry.Zid
	if metaName := entry.MetaName; metaName == "" {
		contentName := entry.ContentName
		contentExt := entry.ContentExt
		if contentName == "" || contentExt == "" {
			log.Panic().Zid(zid).Msg("No meta, no content in getMeta")
		}
		if entry.HasMetaInContent() {
			m, _, err = parseMetaContentFile(zid, filepath.Join(dirPath, contentName))
		} else {
			m = filebox.CalcDefaultMeta(zid, contentExt)
		}
	} else {
		m, err = parseMetaFile(zid, filepath.Join(dirPath, metaName))
	}
	if err == nil {
		cmdCleanupMeta(m, entry)
	}
	cmd.rc <- resGetMeta{m, err}
}

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

func (dp *dirBox) srvGetMetaContent(ctx context.Context, entry *notify.DirEntry, zid id.Zid) (*meta.Meta, []byte, error) {
	rc := make(chan resGetMetaContent, 1)
	dp.getFileChan(zid) <- &fileGetMetaContent{entry, rc}
	ctx, cancel := context.WithTimeout(ctx, serviceTimeout)
	defer cancel()
	select {
	case res := <-rc:

		return res.meta, res.content, res.err
	case <-ctx.Done():
		return nil, nil, ctx.Err()
	}
}

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

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

	entry := cmd.entry
	zid := entry.Zid
	contentName := entry.ContentName
	contentExt := entry.ContentExt
	contentPath := filepath.Join(dirPath, contentName)
	if metaName := entry.MetaName; metaName == "" {
		if contentName == "" || contentExt == "" {
			log.Panic().Zid(zid).Msg("No meta, no content in getMetaContent")
		}
		if entry.HasMetaInContent() {
			m, content, err = parseMetaContentFile(zid, contentPath)
		} else {
			m = filebox.CalcDefaultMeta(zid, contentExt)
			content, err = os.ReadFile(contentPath)
		}
	} else {
		m, err = parseMetaFile(zid, filepath.Join(dirPath, metaName))
		if contentName != "" {
			var err1 error
			content, err1 = os.ReadFile(contentPath)
			if err == nil {
				err = err1
			}
		}
	}
	if err == nil {
		cmdCleanupMeta(m, entry)
	}
	cmd.rc <- resGetMetaContent{m, content, err}
}

// COMMAND: srvSetZettel ----------------------------------------
//
// Writes a new or exsting zettel.

func (dp *dirBox) srvSetZettel(ctx context.Context, entry *notify.DirEntry, zettel domain.Zettel) error {
	rc := make(chan resSetZettel, 1)
	dp.getFileChan(zettel.Meta.Zid) <- &fileSetZettel{entry, zettel, rc}
	ctx, cancel := context.WithTimeout(ctx, serviceTimeout)
	defer cancel()
	select {
	case err := <-rc:

		return err
	case <-ctx.Done():
		return ctx.Err()
	}
}

type fileSetZettel struct {
	entry  *notify.DirEntry
	zettel domain.Zettel
	rc     chan<- resSetZettel
}
type resSetZettel = error

func (cmd *fileSetZettel) run(log *logger.Logger, dirPath string) {

	entry := cmd.entry
	zid := entry.Zid
	contentName := entry.ContentName
	m := cmd.zettel.Meta

	content := cmd.zettel.Content.AsBytes()
	metaName := entry.MetaName
	if metaName == "" {
		if contentName == "" {
			log.Panic().Zid(zid).Msg("No meta, no content in setZettel")
		}
		contentPath := filepath.Join(dirPath, contentName)
		if entry.HasMetaInContent() {
			err := writeZettelFile(contentPath, m, content)
			cmd.rc <- err
			return
		}
		err := writeFileContent(contentPath, content)
		cmd.rc <- err
		return
	}

	err := writeMetaFile(filepath.Join(dirPath, metaName), m)
	if err == nil && contentName != "" {
		err = writeFileContent(filepath.Join(dirPath, contentName), content)
	}
	cmd.rc <- err
}

func writeMetaFile(metaPath string, m *meta.Meta) error {
	metaFile, err := openFileWrite(metaPath)
	if err != nil {
		return err
	}
	err = writeFileZid(metaFile, m.Zid)
	if err == nil {
		_, err = m.WriteComputed(metaFile)
	}
	if err1 := metaFile.Close(); err == nil {
		err = err1
	}
	return err
}

func writeZettelFile(contentPath string, m *meta.Meta, content []byte) error {
	zettelFile, err := openFileWrite(contentPath)
	if err != nil {
		return err
	}
	if err == nil {
		err = writeMetaHeader(zettelFile, m)
	}
	if err == nil {
		_, err = zettelFile.Write(content)
	}
	if err1 := zettelFile.Close(); err == nil {
		err = err1
	}
	return err

}

var (
	newline = []byte{'\n'}
	yamlSep = []byte{'-', '-', '-', '\n'}
)

func writeMetaHeader(w io.Writer, m *meta.Meta) (err error) {
	if m.YamlSep {
		_, err = w.Write(yamlSep)
		if err != nil {
			return err
		}
	}



	err = writeFileZid(w, m.Zid)
	if err != nil {

		return err



	}



	_, err = m.WriteComputed(w)
	if err != nil {
		return err
	}
	if m.YamlSep {
		_, err = w.Write(yamlSep)
	} else {
		_, err = w.Write(newline)
	}
	return err
}

// COMMAND: srvDeleteZettel ----------------------------------------
//
// Deletes an existing zettel.

func (dp *dirBox) srvDeleteZettel(ctx context.Context, entry *notify.DirEntry, zid id.Zid) error {
	rc := make(chan resDeleteZettel, 1)
	dp.getFileChan(zid) <- &fileDeleteZettel{entry, rc}
	ctx, cancel := context.WithTimeout(ctx, serviceTimeout)
	defer cancel()
	select {
	case err := <-rc:

		return err
	case <-ctx.Done():
		return ctx.Err()
	}
}

type fileDeleteZettel struct {
	entry *notify.DirEntry
	rc    chan<- resDeleteZettel
}
type resDeleteZettel = error

func (cmd *fileDeleteZettel) run(log *logger.Logger, dirPath string) {
	var err error

	entry := cmd.entry
	contentName := entry.ContentName
	contentPath := filepath.Join(dirPath, contentName)
	if metaName := entry.MetaName; metaName == "" {
		if contentName == "" {
			log.Panic().Zid(entry.Zid).Msg("No meta, no content in getMetaContent")
		}
		err = os.Remove(contentPath)
	} else {
		if contentName != "" {
			err = os.Remove(contentPath)
		}
		err1 := os.Remove(filepath.Join(dirPath, metaName))
		if err == nil {
			err = err1
		}

	}
	for _, dupName := range entry.UselessFiles {
		err1 := os.Remove(filepath.Join(dirPath, dupName))

		if err == nil {
			err = err1


		}
	}
	cmd.rc <- err
}

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





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

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

func cmdCleanupMeta(m *meta.Meta, entry *notify.DirEntry) {
	filebox.CleanupMeta(
		m,
		entry.Zid,
		entry.ContentExt,
		entry.MetaName != "",
		entry.UselessFiles,
	)
}

func openFileWrite(path string) (*os.File, error) {
	return os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
}

func writeFileZid(w io.Writer, zid id.Zid) error {
	_, err := io.WriteString(w, "id: ")
	if err == nil {
		_, err = w.Write(zid.Bytes())
		if err == nil {
			_, err = io.WriteString(w, "\n")
		}
	}
	return err
}

func writeFileContent(path string, content []byte) error {
	f, err := openFileWrite(path)
	if err == nil {
		_, err = f.Write(content)
		if err1 := f.Close(); err == nil {
			err = err1
		}
	}
	return err
}

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

	"strings"

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

func init() {
	manager.Register("file", func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
		path := getFilepathFromURL(u)
		ext := strings.ToLower(filepath.Ext(path))
		if ext != ".zip" {
			return nil, errors.New("unknown extension '" + ext + "' in box URL: " + u.String())
		}
		return &zipBox{
			log: kernel.Main.GetLogger(kernel.BoxService).Clone().
				Str("box", "zip").Int("boxnum", int64(cdata.Number)).Child(),
			number:   cdata.Number,
			name:     path,
			enricher: cdata.Enricher,
			notify:   cdata.Notify,
		}, nil
	})
}

func getFilepathFromURL(u *url.URL) string {
	name := u.Opaque
	if name == "" {

	m := meta.New(zid)
	m.Set(api.KeyTitle, zid.String())
	m.Set(api.KeySyntax, calculateSyntax(ext))
	return m
}

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

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

	if len(uselessFiles) > 0 {
		m.Set(api.KeyUselessFiles, strings.Join(uselessFiles, " "))
	}
}

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


package filebox

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

	"strings"

	"zettelstore.de/z/box"
	"zettelstore.de/z/box/notify"
	"zettelstore.de/z/domain"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/input"

	"zettelstore.de/z/logger"

	"zettelstore.de/z/search"



)







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

	notify   chan<- box.UpdateInfo
	dirSrv   *notify.DirService
}

func (zb *zipBox) Location() string {
	if strings.HasPrefix(zb.name, "/") {
		return "file://" + zb.name
	}
	return "file:" + zb.name
}

func (zb *zipBox) Start(context.Context) error {
	reader, err := zip.OpenReader(zb.name)
	if err != nil {
		return err
	}
	reader.Close()
	zipNotifier, err := notify.NewSimpleZipNotifier(zb.log, zb.name)
	if err != nil {
		return err
	}
	zb.dirSrv = notify.NewDirService(zb.log, zipNotifier, zb.notify)
	zb.dirSrv.Start()











	return nil
}

func (zb *zipBox) Refresh(_ context.Context) {















	zb.dirSrv.Refresh()



	zb.log.Trace().Msg("Refresh")
}



func (zb *zipBox) Stop(context.Context) {


	zb.dirSrv.Stop()
}

func (*zipBox) CanCreateZettel(context.Context) bool { return false }

func (zb *zipBox) CreateZettel(context.Context, domain.Zettel) (id.Zid, error) {
	err := box.ErrReadOnly
	zb.log.Trace().Err(err).Msg("CreateZettel")
	return id.Invalid, err
}

func (zb *zipBox) GetZettel(_ context.Context, zid id.Zid) (domain.Zettel, error) {
	entry := zb.dirSrv.GetDirEntry(zid)
	if !entry.IsValid() {
		return domain.Zettel{}, box.ErrNotFound
	}
	reader, err := zip.OpenReader(zb.name)
	if err != nil {
		return domain.Zettel{}, err
	}
	defer reader.Close()

	var m *meta.Meta
	var src []byte
	var inMeta bool

	contentName := entry.ContentName
	if metaName := entry.MetaName; metaName == "" {
		if contentName == "" {
			zb.log.Panic().Zid(zid).Msg("No meta, no content in zipBox.GetZettel")
		}
		src, err = readZipFileContent(reader, entry.ContentName)
		if err != nil {
			return domain.Zettel{}, err
		}
		if entry.HasMetaInContent() {
			inp := input.NewInput(src)
			m = meta.NewFromInput(zid, inp)
			src = src[inp.Pos:]
		} else {
			m = CalcDefaultMeta(zid, entry.ContentExt)


		}
	} else {
		m, err = readZipMetaFile(reader, zid, metaName)
		if err != nil {
			return domain.Zettel{}, err
		}
		inMeta = true
		if contentName != "" {
			src, err = readZipFileContent(reader, entry.ContentName)
			if err != nil {
				return domain.Zettel{}, err
			}
		}
	}

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

func (zb *zipBox) GetMeta(_ context.Context, zid id.Zid) (*meta.Meta, error) {
	entry := zb.dirSrv.GetDirEntry(zid)
	if !entry.IsValid() {
		return nil, box.ErrNotFound
	}
	reader, err := zip.OpenReader(zb.name)
	if err != nil {
		return nil, err
	}
	defer reader.Close()
	m, err := zb.readZipMeta(reader, zid, entry)
	zb.log.Trace().Err(err).Zid(zid).Msg("GetMeta")
	return m, err
}

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

func (zb *zipBox) ApplyMeta(ctx context.Context, handle box.MetaFunc, constraint search.RetrievePredicate) error {
	reader, err := zip.OpenReader(zb.name)
	if err != nil {
		return err
	}
	defer reader.Close()
	entries := zb.dirSrv.GetDirEntries(constraint)
	zb.log.Trace().Int("entries", int64(len(entries))).Msg("ApplyMeta")
	for _, entry := range entries {
		if !constraint(entry.Zid) {
			continue
		}
		m, err2 := zb.readZipMeta(reader, entry.Zid, entry)
		if err2 != nil {
			continue
		}
		zb.enricher.Enrich(ctx, m, zb.number)
		handle(m)
	}
	return nil
}

func (*zipBox) CanUpdateZettel(context.Context, domain.Zettel) bool { return false }

func (zb *zipBox) UpdateZettel(context.Context, domain.Zettel) error {
	err := box.ErrReadOnly
	zb.log.Trace().Err(err).Msg("UpdateZettel")
	return err
}

func (zb *zipBox) AllowRenameZettel(_ context.Context, zid id.Zid) bool {
	entry := zb.dirSrv.GetDirEntry(zid)
	return !entry.IsValid()
}

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

	err := box.ErrReadOnly
	if curZid == newZid {
		err = nil
	}
	curEntry := zb.dirSrv.GetDirEntry(curZid)
	if !curEntry.IsValid() {
		err = box.ErrNotFound
	}
	zb.log.Trace().Err(err).Msg("RenameZettel")
	return err
}

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

func (zb *zipBox) DeleteZettel(_ context.Context, zid id.Zid) error {

	err := box.ErrReadOnly
	entry := zb.dirSrv.GetDirEntry(zid)
	if !entry.IsValid() {
		err = box.ErrNotFound
	}
	zb.log.Trace().Err(err).Msg("DeleteZettel")
	return err
}

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

func (zb *zipBox) readZipMeta(reader *zip.ReadCloser, zid id.Zid, entry *notify.DirEntry) (m *meta.Meta, err error) {
	var inMeta bool
	if metaName := entry.MetaName; metaName == "" {
		contentName := entry.ContentName
		contentExt := entry.ContentExt
		if contentName == "" || contentExt == "" {
			zb.log.Panic().Zid(zid).Msg("No meta, no content in getMeta")
		}
		if entry.HasMetaInContent() {
			m, err = readZipMetaFile(reader, zid, contentName)

		} else {
			m = CalcDefaultMeta(zid, contentExt)
		}
	} else {
		m, err = readZipMetaFile(reader, zid, metaName)
	}
	if err == nil {
		CleanupMeta(m, zid, entry.ContentExt, inMeta, entry.UselessFiles)
	}
	return m, err
}

func readZipMetaFile(reader *zip.ReadCloser, zid id.Zid, name string) (*meta.Meta, error) {
	src, err := readZipFileContent(reader, name)
	if err != nil {

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


package box

import (
	"time"

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

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


package manager

import (
	"sync"

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

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


package manager

import (
	"testing"

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

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


package manager

import (
	"bytes"
	"context"
	"errors"

	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	return mgr.started && mgr.boxes[0].CanCreateZettel(ctx)
}

// CreateZettel creates a new zettel.
func (mgr *Manager) CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error) {
	mgr.mgrLog.Debug().Msg("CreateZettel")
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return id.Invalid, box.ErrStopped
	}
	return mgr.boxes[0].CreateZettel(ctx, zettel)
}

// GetZettel retrieves a specific zettel.
func (mgr *Manager) GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
	mgr.mgrLog.Debug().Zid(zid).Msg("GetZettel")
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return domain.Zettel{}, box.ErrStopped
	}
	for i, p := range mgr.boxes {
		if z, err := p.GetZettel(ctx, zid); err != box.ErrNotFound {
			if err == nil {
				mgr.Enrich(ctx, z.Meta, i+1)
			}
			return z, err
		}
	}
	return domain.Zettel{}, box.ErrNotFound
}

// GetAllZettel retrieves a specific zettel from all managed boxes.
func (mgr *Manager) GetAllZettel(ctx context.Context, zid id.Zid) ([]domain.Zettel, error) {
	mgr.mgrLog.Debug().Zid(zid).Msg("GetAllZettel")
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return nil, box.ErrStopped
	}
	var result []domain.Zettel
	for i, p := range mgr.boxes {
		if z, err := p.GetZettel(ctx, zid); err == nil {
			mgr.Enrich(ctx, z.Meta, i+1)
			result = append(result, z)
		}
	}
	return result, nil
}

// GetMeta retrieves just the meta data of a specific zettel.
func (mgr *Manager) GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
	mgr.mgrLog.Debug().Zid(zid).Msg("GetMeta")
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return nil, box.ErrStopped
	}
	return mgr.doGetMeta(ctx, zid)
}

func (mgr *Manager) doGetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
	for i, p := range mgr.boxes {
		if m, err := p.GetMeta(ctx, zid); err != box.ErrNotFound {
			if err == nil {
				mgr.Enrich(ctx, m, i+1)
			}
			return m, err
		}
	}
	return nil, box.ErrNotFound
}

// GetAllMeta retrieves the meta data of a specific zettel from all managed boxes.
func (mgr *Manager) GetAllMeta(ctx context.Context, zid id.Zid) ([]*meta.Meta, error) {
	mgr.mgrLog.Debug().Zid(zid).Msg("GetAllMeta")
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return nil, box.ErrStopped
	}
	var result []*meta.Meta
	for i, p := range mgr.boxes {
		if m, err := p.GetMeta(ctx, zid); err == nil {
			mgr.Enrich(ctx, m, i+1)
			result = append(result, m)
		}
	}
	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")
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return nil, box.ErrStopped
	}
	result := id.Set{}
	for _, p := range mgr.boxes {
		err := p.ApplyZid(ctx, func(zid id.Zid) { result[zid] = true }, func(id.Zid) bool { return true })
		if err != nil {
			return nil, err
		}
	}
	return result, nil
}

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

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

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

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

// UpdateZettel updates an existing zettel.
func (mgr *Manager) UpdateZettel(ctx context.Context, zettel domain.Zettel) error {
	mgr.mgrLog.Debug().Zid(zettel.Meta.Zid).Msg("UpdateZettel")
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return box.ErrStopped
	}
	// Remove all (computed) properties from metadata before storing the zettel.
	zettel.Meta = zettel.Meta.Clone()
	for _, p := range zettel.Meta.ComputedPairsRest() {
		if mgr.propertyKeys[p.Key] {
			zettel.Meta.Delete(p.Key)
		}
	}
	return mgr.boxes[0].UpdateZettel(ctx, zettel)
}

		}
	}
	return true
}

// RenameZettel changes the current zid to a new zid.
func (mgr *Manager) RenameZettel(ctx context.Context, curZid, newZid id.Zid) error {
	mgr.mgrLog.Debug().Zid(curZid).Zid(newZid).Msg("RenameZettel")
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return box.ErrStopped
	}
	for i, p := range mgr.boxes {
		err := p.RenameZettel(ctx, curZid, newZid)

		}
	}
	return false
}

// DeleteZettel removes the zettel from the box.
func (mgr *Manager) DeleteZettel(ctx context.Context, zid id.Zid) error {
	mgr.mgrLog.Debug().Zid(zid).Msg("DeleteZettel")
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if !mgr.started {
		return box.ErrStopped
	}
	for _, p := range mgr.boxes {
		err := p.DeleteZettel(ctx, zid)

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


package manager

import (
	"strings"

	"zettelstore.de/z/ast"
	"zettelstore.de/z/box/manager/store"

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


package manager

import (
	"context"
	"strconv"

	"zettelstore.de/c/api"

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


package manager

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

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

// SearchEqual returns all zettel that contains the given exact word.
// The word must be normalized through Unicode NKFD, trimmed and not empty.
func (mgr *Manager) SearchEqual(word string) id.Set {
	found := mgr.idxStore.SearchEqual(word)
	mgr.idxLog.Debug().Str("word", word).Int("found", int64(len(found))).Msg("SearchEqual")
	if msg := mgr.idxLog.Trace(); msg.Enabled() {
		msg.Str("ids", fmt.Sprint(found)).Msg("IDs")
	}
	return found
}

// SearchPrefix returns all zettel that have a word with the given prefix.
// The prefix must be normalized through Unicode NKFD, trimmed and not empty.
func (mgr *Manager) SearchPrefix(prefix string) id.Set {
	found := mgr.idxStore.SearchPrefix(prefix)
	mgr.idxLog.Debug().Str("prefix", prefix).Int("found", int64(len(found))).Msg("SearchPrefix")
	if msg := mgr.idxLog.Trace(); msg.Enabled() {
		msg.Str("ids", fmt.Sprint(found)).Msg("IDs")
	}
	return found
}

// SearchSuffix returns all zettel that have a word with the given suffix.
// The suffix must be normalized through Unicode NKFD, trimmed and not empty.
func (mgr *Manager) SearchSuffix(suffix string) id.Set {
	found := mgr.idxStore.SearchSuffix(suffix)
	mgr.idxLog.Debug().Str("suffix", suffix).Int("found", int64(len(found))).Msg("SearchSuffix")
	if msg := mgr.idxLog.Trace(); msg.Enabled() {
		msg.Str("ids", fmt.Sprint(found)).Msg("IDs")
	}
	return found
}

// SearchContains returns all zettel that contains the given string.
// The string must be normalized through Unicode NKFD, trimmed and not empty.
func (mgr *Manager) SearchContains(s string) id.Set {
	found := mgr.idxStore.SearchContains(s)
	mgr.idxLog.Debug().Str("s", s).Int("found", int64(len(found))).Msg("SearchContains")
	if msg := mgr.idxLog.Trace(); msg.Enabled() {
		msg.Str("ids", fmt.Sprint(found)).Msg("IDs")
	}
	return found
}

// idxIndexer runs in the background and updates the index data structures.
// This is the main service of the idxIndexer.
func (mgr *Manager) idxIndexer() {
	// Something may panic. Ensure a running indexer.
	defer func() {

	var roomNum uint64
	var start time.Time
	for {
		switch action, zid, arRoomNum := mgr.idxAr.Dequeue(); action {
		case arNothing:
			return
		case arReload:
			mgr.idxLog.Debug().Msg("reload")
			roomNum = 0
			zids, err := mgr.FetchZids(ctx)
			if err == nil {
				start = time.Now()
				if rno := mgr.idxAr.Reload(zids); rno > 0 {
					roomNum = rno
				}
				mgr.idxMx.Lock()
				mgr.idxLastReload = time.Now()
				mgr.idxSinceReload = 0
				mgr.idxMx.Unlock()
			}
		case arUpdate:
			mgr.idxLog.Debug().Zid(zid).Msg("update")
			zettel, err := mgr.GetZettel(ctx, zid)
			if err != nil {
				// TODO: on some errors put the zid into a "try later" set
				continue
			}
			mgr.idxMx.Lock()
			if arRoomNum == roomNum {
				mgr.idxDurReload = time.Since(start)
			}
			mgr.idxSinceReload++
			mgr.idxMx.Unlock()
			mgr.idxUpdateZettel(ctx, zettel)
		case arDelete:
			mgr.idxLog.Debug().Zid(zid).Msg("delete")
			if _, err := mgr.GetMeta(ctx, zid); err == nil {
				// Zettel was not deleted. This might occur, if zettel was
				// deleted in secondary dirbox, but is still present in
				// first dirbox (or vice versa). Re-index zettel in case
				// a hidden zettel was recovered
				mgr.idxLog.Debug().Zid(zid).Msg("not deleted")
				mgr.idxAr.Enqueue(zid, arUpdate)
			}
			mgr.idxMx.Lock()
			mgr.idxSinceReload++
			mgr.idxMx.Unlock()
			mgr.idxDeleteZettel(zid)
		}

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

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

	"zettelstore.de/z/box"
	"zettelstore.de/z/box/manager/memstore"
	"zettelstore.de/z/box/manager/store"
	"zettelstore.de/z/config"
	"zettelstore.de/z/domain/id"
	"zettelstore.de/z/domain/meta"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/logger"
)

// ConnectData contains all administration related values.
type ConnectData struct {
	Number   int // number of the box, starting with 1.
	Config   config.Config
	Enricher box.Enricher

	}
	sort.Strings(result)
	return result
}

// Manager is a coordinating box.
type Manager struct {
	mgrLog       *logger.Logger
	mgrMx        sync.RWMutex
	started      bool
	rtConfig     config.Config
	boxes        []box.ManagedBox
	observers    []box.UpdateFunc
	mxObserver   sync.RWMutex
	done         chan struct{}
	infos        chan box.UpdateInfo
	propertyKeys map[string]bool // Set of property key names

	// Indexer data
	idxLog   *logger.Logger
	idxStore store.Store
	idxAr    *anterooms
	idxReady chan struct{} // Signal a non-empty anteroom to background task

	// Indexer stats data
	idxMx          sync.RWMutex
	idxLastReload  time.Time
	idxDurReload   time.Duration
	idxSinceReload uint64
}

// New creates a new managing box.
func New(boxURIs []*url.URL, authManager auth.BaseManager, rtConfig config.Config) (*Manager, error) {
	propertyKeys := make(map[string]bool)
	for _, kd := range meta.GetSortedKeyDescriptions() {
		if kd.IsProperty() {
			propertyKeys[kd.Name] = true
		}
	}
	boxLog := kernel.Main.GetLogger(kernel.BoxService)
	mgr := &Manager{
		mgrLog:       boxLog.Clone().Str("box", "manager").Child(),
		rtConfig:     rtConfig,
		infos:        make(chan box.UpdateInfo, len(boxURIs)*10),
		propertyKeys: propertyKeys,

		idxLog:   boxLog.Clone().Str("box", "index").Child(),
		idxStore: memstore.New(),
		idxAr:    newAnterooms(10),
		idxReady: make(chan struct{}, 1),
	}
	cdata := ConnectData{Number: 1, Config: rtConfig, Enricher: mgr, Notify: mgr.infos}
	boxes := make([]box.ManagedBox, 0, len(boxURIs)+2)
	for _, uri := range boxURIs {

	if f != nil {
		mgr.mxObserver.Lock()
		mgr.observers = append(mgr.observers, f)
		mgr.mxObserver.Unlock()
	}
}










func (mgr *Manager) notifier() {
	// The call to notify may panic. Ensure a running notifier.
	defer func() {
		if r := recover(); r != nil {
			kernel.Main.LogRecover("Notifier", r)
			go mgr.notifier()
		}
	}()

	tsLastEvent := time.Now()
	cache := destutterCache{}
	for {
		select {
		case ci, ok := <-mgr.infos:
			if ok {
				now := time.Now()
				if len(cache) > 1 && tsLastEvent.Add(10*time.Second).Before(now) {
					// Cache contains entries and is definitely outdated
					mgr.mgrLog.Trace().Msg("clean destutter cache")
					cache = destutterCache{}
				}
				tsLastEvent = now

				reason, zid := ci.Reason, ci.Zid
				mgr.mgrLog.Debug().Uint("reason", uint64(reason)).Zid(zid).Msg("notifier")
				if ignoreUpdate(cache, now, reason, zid) {
					mgr.mgrLog.Trace().Uint("reason", uint64(reason)).Zid(zid).Msg("notifier ignored")
					continue
				}
				mgr.idxEnqueue(reason, zid)
				if ci.Box == nil {
					ci.Box = mgr
				}
				mgr.notifyObserver(&ci)
			}
		case <-mgr.done:
			return
		}
	}
}

type destutterData struct {
	deadAt time.Time
	reason box.UpdateReason
}
type destutterCache = map[id.Zid]destutterData

func ignoreUpdate(cache destutterCache, now time.Time, reason box.UpdateReason, zid id.Zid) bool {
	if dsd, found := cache[zid]; found {
		if dsd.reason == reason && dsd.deadAt.After(now) {
			return true
		}
	}
	cache[zid] = destutterData{
		deadAt: now.Add(500 * time.Millisecond),
		reason: reason,
	}
	return false
}

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

func (mgr *Manager) notifyObserver(ci *box.UpdateInfo) {
	mgr.mxObserver.RLock()
	observers := mgr.observers
	mgr.mxObserver.RUnlock()
	for _, ob := range observers {
		ob(*ci)
	}
}

// Start the box. Now all other functions of the box are allowed.
// Starting an already started box is not allowed.
func (mgr *Manager) Start(ctx context.Context) error {
	mgr.mgrMx.Lock()
	if mgr.started {
		mgr.mgrMx.Unlock()

		return err
	}
	mgr.idxAr.Reset() // Ensure an initial index run
	mgr.done = make(chan struct{})
	go mgr.notifier()
	go mgr.idxIndexer()


	mgr.started = true
	mgr.mgrMx.Unlock()

	return nil
}

// Stop the started box. Now only the Start() function is allowed.
func (mgr *Manager) Stop(ctx context.Context) {
	mgr.mgrMx.Lock()
	defer mgr.mgrMx.Unlock()
	if !mgr.started {
		return
	}
	close(mgr.done)
	for _, p := range mgr.boxes {
		if ss, ok := p.(box.StartStopper); ok {
			ss.Stop(ctx)
		}
	}
	mgr.started = false
}

// Refresh internal box data.
func (mgr *Manager) Refresh(ctx context.Context) error {
	mgr.mgrLog.Debug().Msg("Refresh")
	mgr.mgrMx.Lock()
	defer mgr.mgrMx.Unlock()
	if !mgr.started {
		return box.ErrStopped
	}
	mgr.infos <- box.UpdateInfo{Reason: box.OnReload, Zid: id.Invalid}

	for _, bx := range mgr.boxes {
		if rb, ok := bx.(box.Refresher); ok {
			rb.Refresh(ctx)

		}
	}


	return nil
}

// ReadStats populates st with box statistics.
func (mgr *Manager) ReadStats(st *box.Stats) {
	mgr.mgrLog.Debug().Msg("ReadStats")
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	subStats := make([]box.ManagedBoxStats, len(mgr.boxes))
	for i, p := range mgr.boxes {
		p.ReadStats(&subStats[i])
	}

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

	result.AddSlice(zi.backward)
	for _, mref := range zi.meta {
		result.AddSlice(mref.backward)
	}
}

func removeOtherMetaRefs(m *meta.Meta, back id.Slice) id.Slice {
	for _, p := range m.PairsRest() {
		switch meta.Type(p.Key) {
		case meta.TypeID:
			if zid, err := id.Parse(p.Value); err == nil {
				back = remRef(back, zid)
			}
		case meta.TypeIDSet:
			for _, val := range meta.ListFromValue(p.Value) {

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


package memstore

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

func refsDiff(refsN, refsO id.Slice) (newRefs, remRefs id.Slice) {
	npos, opos := 0, 0
	for npos < len(refsN) && opos < len(refsO) {

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


package memstore

import (
	"testing"

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

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


package store

// WordSet contains the set of all words, with the count of their occurrences.
type WordSet map[string]int

// NewWordSet returns a new WordSet.
func NewWordSet() WordSet { return make(WordSet) }

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


package store_test

import (
	"sort"
	"testing"

	"zettelstore.de/z/box/manager/store"

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


package store

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

// ZettelIndex contains all index data of a zettel.
type ZettelIndex struct {
	Zid      id.Zid            // zid of the indexed zettel

	"sync"

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

func init() {
	manager.Register(
		"mem",
		func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
			return &memBox{
				log: kernel.Main.GetLogger(kernel.BoxService).Clone().
					Str("box", "mem").Int("boxnum", int64(cdata.Number)).Child(),
				u:     u,
				cdata: *cdata,
			}, nil
		})
}

type memBox struct {
	log    *logger.Logger
	u      *url.URL
	cdata  manager.ConnectData
	zettel map[id.Zid]domain.Zettel
	mx     sync.RWMutex
}

func (mb *memBox) notifyChanged(reason box.UpdateReason, zid id.Zid) {
	if chci := mb.cdata.Notify; chci != nil {
		chci <- box.UpdateInfo{Reason: reason, Zid: zid}
	}
}

func (mb *memBox) Location() string {
	return mb.u.String()
}

func (mb *memBox) Start(context.Context) error {
	mb.mx.Lock()
	mb.zettel = make(map[id.Zid]domain.Zettel)
	mb.mx.Unlock()
	return nil
}

func (mb *memBox) Stop(context.Context) {
	mb.mx.Lock()
	mb.zettel = nil
	mb.mx.Unlock()

}

func (*memBox) CanCreateZettel(context.Context) bool { return true }

func (mb *memBox) CreateZettel(_ context.Context, zettel domain.Zettel) (id.Zid, error) {
	mb.mx.Lock()
	zid, err := box.GetNewZid(func(zid id.Zid) (bool, error) {
		_, ok := mb.zettel[zid]
		return !ok, nil
	})
	if err != nil {
		mb.mx.Unlock()
		return id.Invalid, err
	}
	meta := zettel.Meta.Clone()
	meta.Zid = zid
	zettel.Meta = meta
	mb.zettel[zid] = zettel
	mb.mx.Unlock()
	mb.notifyChanged(box.OnUpdate, zid)
	mb.log.Trace().Zid(zid).Msg("CreateZettel")
	return zid, nil
}

func (mb *memBox) GetZettel(_ context.Context, zid id.Zid) (domain.Zettel, error) {
	mb.mx.RLock()
	zettel, ok := mb.zettel[zid]
	mb.mx.RUnlock()
	if !ok {
		return domain.Zettel{}, box.ErrNotFound
	}
	zettel.Meta = zettel.Meta.Clone()
	mb.log.Trace().Msg("GetZettel")
	return zettel, nil
}

func (mb *memBox) GetMeta(_ context.Context, zid id.Zid) (*meta.Meta, error) {
	mb.mx.RLock()
	zettel, ok := mb.zettel[zid]
	mb.mx.RUnlock()
	if !ok {
		return nil, box.ErrNotFound
	}
	mb.log.Trace().Msg("GetMeta")
	return zettel.Meta.Clone(), nil
}

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

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

func (*memBox) CanUpdateZettel(context.Context, domain.Zettel) bool { return true }

func (mb *memBox) UpdateZettel(_ context.Context, zettel domain.Zettel) error {
	mb.mx.Lock()
	meta := zettel.Meta.Clone()
	if !meta.Zid.IsValid() {
		return &box.ErrInvalidID{Zid: meta.Zid}
	}
	zettel.Meta = meta
	mb.zettel[meta.Zid] = zettel
	mb.mx.Unlock()
	mb.notifyChanged(box.OnUpdate, meta.Zid)
	mb.log.Trace().Msg("UpdateZettel")
	return nil
}

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

func (mb *memBox) RenameZettel(_ context.Context, curZid, newZid id.Zid) error {
	mb.mx.Lock()
	zettel, ok := mb.zettel[curZid]
	if !ok {
		mb.mx.Unlock()
		return box.ErrNotFound
	}

	// Check that there is no zettel with newZid
	if _, ok = mb.zettel[newZid]; ok {
		mb.mx.Unlock()
		return &box.ErrInvalidID{Zid: newZid}
	}

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

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

func (mb *memBox) DeleteZettel(_ context.Context, zid id.Zid) error {
	mb.mx.Lock()
	if _, ok := mb.zettel[zid]; !ok {
		mb.mx.Unlock()
		return box.ErrNotFound
	}
	delete(mb.zettel, zid)
	mb.mx.Unlock()
	mb.notifyChanged(box.OnDelete, zid)
	mb.log.Trace().Msg("DeleteZettel")
	return nil
}

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

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

package notify

import (
	"errors"
	"fmt"
	"path/filepath"
	"regexp"
	"strings"
	"sync"

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

type entrySet map[id.Zid]*DirEntry

// directoryState signal the internal state of the service.
//
// The following state transitions are possible:
// --newDirService--> dsCreated
// dsCreated --Start--> dsStarting
// dsStarting --last list notification--> dsWorking
// dsWorking --directory missing--> dsMissing
// dsMissing --last list notification--> dsWorking
// --Stop--> dsStopping
type directoryState uint8

const (
	dsCreated  directoryState = iota
	dsStarting                // Reading inital scan
	dsWorking                 // Initial scan complete, fully operational
	dsMissing                 // Directory is missing
	dsStopping                // Service is shut down
)

// DirService specifies a directory service for file based zettel.
type DirService struct {
	log      *logger.Logger
	dirPath  string
	notifier Notifier
	infos    chan<- box.UpdateInfo
	mx       sync.RWMutex // protects status, entries
	state    directoryState
	entries  entrySet
}

// ErrNoDirectory signals missing directory data.
var ErrNoDirectory = errors.New("unable to retrieve zettel directory information")

// NewDirService creates a new directory service.
func NewDirService(log *logger.Logger, notifier Notifier, chci chan<- box.UpdateInfo) *DirService {
	return &DirService{
		log:      log,
		notifier: notifier,
		infos:    chci,
		state:    dsCreated,
	}
}

// Start the directory service.
func (ds *DirService) Start() {
	ds.mx.Lock()
	ds.state = dsStarting
	ds.mx.Unlock()
	go ds.updateEvents()
}

// Refresh the directory entries.
func (ds *DirService) Refresh() {
	ds.notifier.Refresh()
}

// Stop the directory service.
func (ds *DirService) Stop() {
	ds.mx.Lock()
	ds.state = dsStopping
	ds.mx.Unlock()
	ds.notifier.Close()
}

func (ds *DirService) logMissingEntry(action string) error {
	err := ErrNoDirectory
	ds.log.Info().Err(err).Str("action", action).Msg("Unable to get directory information")
	return err
}

// NumDirEntries returns the number of entries in the directory.
func (ds *DirService) NumDirEntries() int {
	ds.mx.RLock()
	defer ds.mx.RUnlock()
	if ds.entries == nil {
		return 0
	}
	return len(ds.entries)
}

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

// GetDirEntry returns a directory entry with the given zid, or nil if not found.
func (ds *DirService) GetDirEntry(zid id.Zid) *DirEntry {
	ds.mx.RLock()
	defer ds.mx.RUnlock()
	if ds.entries == nil {
		return nil
	}
	foundEntry := ds.entries[zid]
	if foundEntry == nil {
		return nil
	}
	result := *foundEntry
	return &result
}

// SetNewDirEntry calculates an empty directory entry with an unused identifier and
// stores it in the directory.
func (ds *DirService) SetNewDirEntry() (id.Zid, error) {
	ds.mx.Lock()
	defer ds.mx.Unlock()
	if ds.entries == nil {
		return id.Invalid, ds.logMissingEntry("new")
	}
	zid, err := box.GetNewZid(func(zid id.Zid) (bool, error) {
		_, found := ds.entries[zid]
		return !found, nil
	})
	if err != nil {
		return id.Invalid, err
	}
	ds.entries[zid] = &DirEntry{Zid: zid}
	return zid, nil
}

// UpdateDirEntry updates an directory entry in place.
func (ds *DirService) UpdateDirEntry(updatedEntry *DirEntry) error {
	entry := *updatedEntry
	ds.mx.Lock()
	defer ds.mx.Unlock()
	if ds.entries == nil {
		return ds.logMissingEntry("update")
	}
	ds.entries[entry.Zid] = &entry
	return nil
}

// RenameDirEntry replaces an existing directory entry with a new one.
func (ds *DirService) RenameDirEntry(oldEntry *DirEntry, newZid id.Zid) (DirEntry, error) {
	ds.mx.Lock()
	defer ds.mx.Unlock()
	if ds.entries == nil {
		return DirEntry{}, ds.logMissingEntry("rename")
	}
	if _, found := ds.entries[newZid]; found {
		return DirEntry{}, &box.ErrInvalidID{Zid: newZid}
	}
	oldZid := oldEntry.Zid
	newEntry := DirEntry{
		Zid:         newZid,
		MetaName:    renameFilename(oldEntry.MetaName, oldZid, newZid),
		ContentName: renameFilename(oldEntry.ContentName, oldZid, newZid),
		ContentExt:  oldEntry.ContentExt,
		// Duplicates must not be set, because duplicates will be deleted
	}
	delete(ds.entries, oldZid)
	ds.entries[newZid] = &newEntry
	return newEntry, nil
}

func renameFilename(name string, curID, newID id.Zid) string {
	if cur := curID.String(); strings.HasPrefix(name, cur) {
		name = newID.String() + name[len(cur):]
	}
	return name
}

// DeleteDirEntry removes a entry from the directory.
func (ds *DirService) DeleteDirEntry(zid id.Zid) error {
	ds.mx.Lock()
	defer ds.mx.Unlock()
	if ds.entries == nil {
		return ds.logMissingEntry("delete")
	}
	delete(ds.entries, zid)
	return nil
}

func (ds *DirService) updateEvents() {
	var newEntries entrySet
	for ev := range ds.notifier.Events() {
		ds.mx.RLock()
		state := ds.state
		ds.mx.RUnlock()

		if msg := ds.log.Trace(); msg.Enabled() {
			msg.Uint("state", uint64(state)).Str("op", ev.Op.String()).Str("name", ev.Name).Msg("notifyEvent")
		}
		if state == dsStopping {
			break
		}

		switch ev.Op {
		case Error:
			newEntries = nil
			if state != dsMissing {
				ds.log.Warn().Err(ev.Err).Msg("Notifier confused")
			}
		case Make:
			newEntries = make(entrySet)
		case List:
			if ev.Name == "" {
				zids := getNewZids(newEntries)
				ds.mx.Lock()
				fromMissing := ds.state == dsMissing
				prevEntries := ds.entries
				ds.entries = newEntries
				ds.state = dsWorking
				ds.mx.Unlock()
				newEntries = nil
				ds.onCreateDirectory(zids, prevEntries)
				if fromMissing {
					ds.log.Info().Str("path", ds.dirPath).Msg("Zettel directory found")
				}
			} else if newEntries != nil {
				ds.onUpdateFileEvent(newEntries, ev.Name)
			}
		case Destroy:
			newEntries = nil
			ds.onDestroyDirectory()
			ds.log.Error().Str("path", ds.dirPath).Msg("Zettel directory missing")
		case Update:
			ds.mx.Lock()
			zid := ds.onUpdateFileEvent(ds.entries, ev.Name)
			ds.mx.Unlock()
			if zid != id.Invalid {
				ds.notifyChange(box.OnUpdate, zid)
			}
		case Delete:
			ds.mx.Lock()
			ds.onDeleteFileEvent(ds.entries, ev.Name)
			ds.mx.Unlock()
		default:
			ds.log.Warn().Str("event", fmt.Sprintf("%v", ev)).Msg("Unknown zettel notification event")
		}
	}
}

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

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

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

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

var validFileName = regexp.MustCompile(`^(\d{14}).*?(\.(.+))?$`)

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

func seekZidExt(name string) (id.Zid, string) {
	match := matchValidFileName(name)
	if len(match) == 0 {
		return id.Invalid, ""
	}
	zid, err := id.Parse(match[1])
	if err != nil {
		return id.Invalid, ""
	}
	return zid, match[3]
}

func fetchdirEntry(entries entrySet, zid id.Zid) *DirEntry {
	if entry, found := entries[zid]; found {
		return entry
	}
	entry := &DirEntry{Zid: zid}
	entries[zid] = entry
	return entry
}

func (ds *DirService) onUpdateFileEvent(entries entrySet, name string) id.Zid {
	if entries == nil {
		return id.Invalid
	}
	zid, ext := seekZidExt(name)
	if zid == id.Invalid {
		return id.Invalid
	}
	entry := fetchdirEntry(entries, zid)
	dupName1, dupName2 := updateEntry(ds.log, entry, name, ext)
	if dupName1 != "" {
		ds.log.Warn().Str("name", dupName1).Msg("Duplicate content (is ignored)")
		if dupName2 != "" {
			ds.log.Warn().Str("name", dupName2).Msg("Duplicate content (is ignored)")
		}
	}
	return zid
}

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

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

func replayUpdateUselessFiles(entry *DirEntry) {
	uselessFiles := entry.UselessFiles
	if len(uselessFiles) == 0 {
		return
	}
	entry.UselessFiles = make([]string, 0, len(uselessFiles))
	for _, name := range uselessFiles {
		updateEntry(nil, entry, name, onlyExt(name))
	}
}

const extMeta = "meta"

func updateEntry(log *logger.Logger, entry *DirEntry, name, ext string) (string, string) {
	if (ext == "" || ext == extMeta) && !extIsMetaAndContent(entry.ContentExt) {
		return updateEntryMeta(log, entry, name, ext), ""
	}
	return updateEntryContent(entry, name, ext)
}
func updateEntryMeta(log *logger.Logger, entry *DirEntry, name, ext string) string {
	metaName := entry.MetaName
	if metaName == "" {
		if log != nil && ext == extMeta {
			log.Warn().Str("name", name).Msg("Metadata file should not end with .meta any more")
		}
		entry.MetaName = name
		return ""
	}
	if metaName == name {
		return ""
	}
	metaExt := onlyExt(metaName)
	if metaExt == ext {
		if newNameIsBetter(metaName, name) {
			entry.MetaName = name
			return addUselessFile(entry, metaName)
		}
		return addUselessFile(entry, name)
	}
	if metaExt == "" {
		return addUselessFile(entry, name)
	}
	if ext == "" {
		entry.MetaName = name
		return addUselessFile(entry, metaName)
	}
	panic(name)
}
func updateEntryContent(entry *DirEntry, name, ext string) (string, string) {
	contentName := entry.ContentName
	if contentName == "" {
		entry.ContentName = name
		entry.ContentExt = ext
		return "", ""
	}
	if contentName == name {
		return "", ""
	}
	contentExt := entry.ContentExt
	if contentExt == ext {
		if newNameIsBetter(contentName, name) {
			entry.ContentName = name
			return addUselessFile(entry, contentName), ""
		}
		return addUselessFile(entry, name), ""
	}
	if contentExt == extZettel {
		return addUselessFile(entry, name), ""
	}
	if ext == extZettel {
		entry.ContentName = name
		entry.ContentExt = ext
		contentName = addUselessFile(entry, contentName)
		if metaName := entry.MetaName; metaName != "" {
			metaName = addUselessFile(entry, metaName)
			entry.MetaName = ""
			return contentName, metaName
		}
		return contentName, ""
	}
	if newExtIsBetter(contentExt, ext) {
		entry.ContentName = name
		entry.ContentExt = ext
		return addUselessFile(entry, contentName), ""
	}
	return addUselessFile(entry, name), ""
}
func addUselessFile(entry *DirEntry, name string) string {
	for _, dupName := range entry.UselessFiles {
		if name == dupName {
			return ""
		}
	}
	entry.UselessFiles = append(entry.UselessFiles, name)
	return name
}

func onlyExt(name string) string {
	ext := filepath.Ext(name)
	if ext == "" || ext[0] != '.' {
		return ext
	}
	return ext[1:]
}

func newNameIsBetter(oldName, newName string) bool {
	if len(oldName) < len(newName) {
		return false
	}
	return oldName > newName
}

var supportedSyntax, isPrimarySyntax map[string]bool

func init() {
	syntaxList := parser.GetSyntaxes()
	supportedSyntax = make(map[string]bool, len(syntaxList))
	isPrimarySyntax = make(map[string]bool, len(syntaxList))
	for _, syntax := range syntaxList {
		supportedSyntax[syntax] = true
		isPrimarySyntax[syntax] = parser.Get(syntax).Name == syntax
	}
}
func newExtIsBetter(oldExt, newExt string) bool {
	oldSyntax := supportedSyntax[oldExt]
	if oldSyntax != supportedSyntax[newExt] {
		return !oldSyntax
	}
	if oldSyntax {
		if oldExt == "zmk" {
			return false
		}
		if newExt == "zmk" {
			return true
		}
		oldInfo := parser.Get(oldExt)
		newInfo := parser.Get(newExt)
		if oldTextParser := oldInfo.IsTextParser; oldTextParser != newInfo.IsTextParser {
			return !oldTextParser
		}
		if oldImageFormat := oldInfo.IsImageFormat; oldImageFormat != newInfo.IsImageFormat {
			return oldImageFormat
		}
		if oldPrimary := isPrimarySyntax[oldExt]; oldPrimary != isPrimarySyntax[newExt] {
			return !oldPrimary
		}
	}

	oldLen := len(oldExt)
	newLen := len(newExt)
	if oldLen != newLen {
		return newLen < oldLen
	}
	return newExt < oldExt
}

func (ds *DirService) notifyChange(reason box.UpdateReason, zid id.Zid) {
	if chci := ds.infos; chci != nil {
		ds.log.Trace().Zid(zid).Uint("reason", uint64(reason)).Msg("notifyChange")
		chci <- box.UpdateInfo{Reason: reason, Zid: zid}
	}
}

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

package notify

import (
	"testing"

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

func TestSeekZidExt(t *testing.T) {
	testcases := []struct {
		name string
		zid  id.Zid
		ext  string
	}{
		{"", id.Invalid, ""},
		{"12345678901234.ext", id.Zid(12345678901234), "ext"},
		{"12345678901234 abc.ext", id.Zid(12345678901234), "ext"},
		{"12345678901234", id.Zid(12345678901234), ""},
		{"12345678901234 def", id.Zid(12345678901234), ""},
	}
	for _, tc := range testcases {
		gotZid, gotExt := seekZidExt(tc.name)
		if gotZid != tc.zid {
			t.Errorf("seekZidExt(%q) == %v, but got %v", tc.name, tc.zid, gotZid)
		} else if gotExt != tc.ext {
			t.Errorf("seekZidExt(%q) == %q, but got %q", tc.name, tc.ext, gotExt)
		}
	}
}

func TestNewExtIsBetter(t *testing.T) {
	extVals := []string{
		// Main Formats
		api.ValueSyntaxZmk, "markdown", "md",
		// Other supported text formats
		"css", "txt", "html", api.ValueSyntaxNone, "mustache", "text", "plain",
		// Supported graphics formats
		"gif", "png", "svg", "jpeg", "jpg",
		// Unsupported syntax values
		"gz", "cpp", "tar", "cppc",
	}
	for oldI, oldExt := range extVals {
		for newI, newExt := range extVals {
			if oldI <= newI {
				continue
			}
			if !newExtIsBetter(oldExt, newExt) {
				t.Errorf("newExtIsBetter(%q, %q) == true, but got false", oldExt, newExt)
			}
			if newExtIsBetter(newExt, oldExt) {
				t.Errorf("newExtIsBetter(%q, %q) == false, but got true", newExt, oldExt)
			}
		}
	}
}

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

package notify

import (
	"path/filepath"

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

const (
	extZettel = "zettel" // file contains metadata and content
	extBin    = "bin"    // file contains binary content
	extTxt    = "txt"    // file contains non-binary content
)

func extIsMetaAndContent(ext string) bool { return ext == extZettel }

// DirEntry stores everything for a directory entry.
type DirEntry struct {
	Zid          id.Zid
	MetaName     string   // file name of meta information
	ContentName  string   // file name of zettel content
	ContentExt   string   // (normalized) file extension of zettel content
	UselessFiles []string // list of other content files
}

// IsValid checks whether the entry is valid.
func (e *DirEntry) IsValid() bool {
	return e != nil && e.Zid.IsValid()
}

// HasMetaInContent returns true, if metadata will be stored in the content file.
func (e *DirEntry) HasMetaInContent() bool {
	return e.IsValid() && extIsMetaAndContent(e.ContentExt)
}

// SetupFromMetaContent fills entry data based on metadata and zettel content.
func (e *DirEntry) SetupFromMetaContent(m *meta.Meta, content domain.Content, getZettelFileSyntax func() []string) {
	if e.Zid != m.Zid {
		panic("Zid differ")
	}
	if contentName := e.ContentName; contentName != "" {
		if !extIsMetaAndContent(e.ContentExt) && e.MetaName == "" {
			e.MetaName = e.calcBaseName(contentName)
		}
		return
	}

	syntax := m.GetDefault(api.KeySyntax, "")
	ext := calcContentExt(syntax, m.YamlSep, getZettelFileSyntax)
	metaName := e.MetaName
	eimc := extIsMetaAndContent(ext)
	if eimc {
		if metaName != "" {
			ext = contentExtWithMeta(syntax, content)
		}
		e.ContentName = e.calcBaseName(metaName) + "." + ext
		e.ContentExt = ext
	} else {
		if len(content.AsBytes()) > 0 {
			e.ContentName = e.calcBaseName(metaName) + "." + ext
			e.ContentExt = ext
		}
		if metaName == "" {
			e.MetaName = e.calcBaseName(e.ContentName)
		}
	}
}

func contentExtWithMeta(syntax string, content domain.Content) string {
	p := parser.Get(syntax)
	if content.IsBinary() {
		if p.IsImageFormat {
			return syntax
		}
		return extBin
	}
	if p.IsImageFormat {
		return extTxt
	}
	return syntax
}

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

}

func (e *DirEntry) calcBaseName(name string) string {
	if name == "" {
		return e.Zid.String()
	}
	return name[0 : len(name)-len(filepath.Ext(name))]

}

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

package notify

import (
	"os"
	"path/filepath"
	"strings"

	"github.com/fsnotify/fsnotify"
	"zettelstore.de/z/logger"
)

type fsdirNotifier struct {
	log     *logger.Logger
	events  chan Event
	done    chan struct{}
	refresh chan struct{}
	base    *fsnotify.Watcher
	path    string
	fetcher EntryFetcher
	parent  string
}

// NewFSDirNotifier creates a directory based notifier that receives notifications
// from the file system.
func NewFSDirNotifier(log *logger.Logger, path string) (Notifier, error) {
	absPath, err := filepath.Abs(path)
	if err != nil {
		log.Debug().Err(err).Str("path", path).Msg("Unable to create absolute path")
		return nil, err
	}
	watcher, err := fsnotify.NewWatcher()
	if err != nil {
		log.Debug().Err(err).Str("absPath", absPath).Msg("Unable to create watcher")
		return nil, err
	}
	absParentDir := filepath.Dir(absPath)
	errParent := watcher.Add(absParentDir)
	err = watcher.Add(absPath)
	if errParent != nil {
		if err != nil {
			log.Error().
				Str("parentDir", absParentDir).Err(errParent).
				Str("path", absPath).Err(err).
				Msg("Unable to access Zettel directory and its parent directory")
			watcher.Close()
			return nil, err
		}
		log.Warn().
			Str("parentDir", absParentDir).Err(errParent).
			Msg("Parent of Zettel directory cannot be supervised")
		log.Warn().Str("path", absPath).
			Msg("Zettelstore might not detect a deletion or movement of the Zettel directory")
	} else if err != nil {
		// Not a problem, if container is not available. It might become available later.
		log.Warn().Err(err).Str("path", absPath).Msg("Zettel directory not available")
	}

	fsdn := &fsdirNotifier{
		log:     log,
		events:  make(chan Event),
		refresh: make(chan struct{}),
		done:    make(chan struct{}),
		base:    watcher,
		path:    absPath,
		fetcher: newDirPathFetcher(absPath),
		parent:  absParentDir,
	}
	go fsdn.eventLoop()
	return fsdn, nil
}

func (fsdn *fsdirNotifier) Events() <-chan Event {
	return fsdn.events
}

func (fsdn *fsdirNotifier) Refresh() {
	fsdn.refresh <- struct{}{}
}

func (fsdn *fsdirNotifier) eventLoop() {
	defer fsdn.base.Close()
	defer close(fsdn.events)
	defer close(fsdn.refresh)
	if !listDirElements(fsdn.log, fsdn.fetcher, fsdn.events, fsdn.done) {
		return
	}
	for fsdn.readAndProcessEvent() {
	}
}

func (fsdn *fsdirNotifier) readAndProcessEvent() bool {
	select {
	case <-fsdn.done:
		return false
	default:
	}
	select {
	case <-fsdn.done:
		return false
	case <-fsdn.refresh:
		listDirElements(fsdn.log, fsdn.fetcher, fsdn.events, fsdn.done)
	case err, ok := <-fsdn.base.Errors:
		if !ok {
			return false
		}
		select {
		case fsdn.events <- Event{Op: Error, Err: err}:
		case <-fsdn.done:
			return false
		}
	case ev, ok := <-fsdn.base.Events:
		if !ok {
			return false
		}
		if !fsdn.processEvent(&ev) {
			return false
		}
	}
	return true
}

func (fsdn *fsdirNotifier) processEvent(ev *fsnotify.Event) bool {
	if strings.HasPrefix(ev.Name, fsdn.path) {
		if len(ev.Name) == len(fsdn.path) {
			return fsdn.processDirEvent(ev)
		}
		return fsdn.processFileEvent(ev)
	}
	return true
}

const deleteFsOps = fsnotify.Remove | fsnotify.Rename
const updateFsOps = fsnotify.Create | fsnotify.Write

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

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

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

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

package notify

import (
	"archive/zip"
	"os"

	"zettelstore.de/z/logger"
)

// MakeMetaFilename builds the name of the file containing metadata.
func MakeMetaFilename(basename string) string {
	return basename //+ ".meta"
}

// EntryFetcher return a list of (file) names of an directory.
type EntryFetcher interface {
	Fetch() ([]string, error)
}

type dirPathFetcher struct {
	dirPath string
}

func newDirPathFetcher(dirPath string) EntryFetcher { return &dirPathFetcher{dirPath} }

func (dpf *dirPathFetcher) Fetch() ([]string, error) {
	entries, err := os.ReadDir(dpf.dirPath)
	if err != nil {
		return nil, err
	}
	result := make([]string, 0, len(entries))
	for _, entry := range entries {
		if info, err1 := entry.Info(); err1 != nil || !info.Mode().IsRegular() {
			continue
		}
		result = append(result, entry.Name())
	}
	return result, nil
}

type zipPathFetcher struct {
	zipPath string
}

func newZipPathFetcher(zipPath string) EntryFetcher { return &zipPathFetcher{zipPath} }

func (zpf *zipPathFetcher) Fetch() ([]string, error) {
	reader, err := zip.OpenReader(zpf.zipPath)
	if err != nil {
		return nil, err
	}
	defer reader.Close()
	result := make([]string, 0, len(reader.File))
	for _, f := range reader.File {
		result = append(result, f.Name)
	}
	return result, nil
}

// listDirElements write all files within the directory path as events.
func listDirElements(log *logger.Logger, fetcher EntryFetcher, events chan<- Event, done <-chan struct{}) bool {
	select {
	case events <- Event{Op: Make}:
	case <-done:
		return false
	}
	entries, err := fetcher.Fetch()
	if err != nil {
		select {
		case events <- Event{Op: Error, Err: err}:
		case <-done:
			return false
		}
	}
	for _, name := range entries {
		log.Trace().Str("name", name).Msg("File listed")
		select {
		case events <- Event{Op: List, Name: name}:
		case <-done:
			return false
		}
	}

	select {
	case events <- Event{Op: List}:
	case <-done:
		return false
	}
	return true
}

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

// Package notify provides some notification services to be used by box services.
package notify

import "fmt"

// Notifier send events about their container and content.
type Notifier interface {
	// Return the channel
	Events() <-chan Event

	// Signal a refresh of the container. This will result in some events.
	Refresh()

	// Close the notifier (and eventually the channel)
	Close()
}

// EventOp describe a notification operation.
type EventOp uint8

// Valid constants for event operations.
//
// Error signals a detected error. Details are in Event.Err.
//
// Make signals that the container is detected. List events will follow.
//
// List signals a found file, if Event.Name is not empty. Otherwise it signals
//      the end of files within the container.
//
// Destroy signals that the container is not there any more. It might me Make later again.
//
// Update signals that file Event.Name was created/updated. File name is relative
//        to the container.
//
// Delete signals that file Event.Name was removed. File name is relative to
//        the container's name.
const (
	_       EventOp = iota
	Error           // Error while operating
	Make            // Make container
	List            // List container
	Destroy         // Destroy container
	Update          // Update element
	Delete          // Delete element
)

// String representation of operation code.
func (c EventOp) String() string {
	switch c {
	case Error:
		return "ERROR"
	case Make:
		return "MAKE"
	case List:
		return "LIST"
	case Destroy:
		return "DESTROY"
	case Update:
		return "UPDATE"
	case Delete:
		return "DELETE"
	default:
		return fmt.Sprintf("UNKNOWN(%d)", c)
	}
}

// Event represents a single container / element event.
type Event struct {
	Op   EventOp
	Name string
	Err  error // Valid iff Op == Error
}

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

package notify

import (
	"path/filepath"

	"zettelstore.de/z/logger"
)

type simpleDirNotifier struct {
	log     *logger.Logger
	events  chan Event
	done    chan struct{}
	refresh chan struct{}
	fetcher EntryFetcher
}

// NewSimpleDirNotifier creates a directory based notifier that will not receive
// any notifications from the operating system.
func NewSimpleDirNotifier(log *logger.Logger, path string) (Notifier, error) {
	absPath, err := filepath.Abs(path)
	if err != nil {
		return nil, err
	}
	sdn := &simpleDirNotifier{
		log:     log,
		events:  make(chan Event),
		done:    make(chan struct{}),
		refresh: make(chan struct{}),
		fetcher: newDirPathFetcher(absPath),
	}
	go sdn.eventLoop()
	return sdn, nil
}

// NewSimpleZipNotifier creates a zip-file based notifier that will not receive
// any notifications from the operating system.
func NewSimpleZipNotifier(log *logger.Logger, zipPath string) (Notifier, error) {
	sdn := &simpleDirNotifier{
		log:     log,
		events:  make(chan Event),
		done:    make(chan struct{}),
		refresh: make(chan struct{}),
		fetcher: newZipPathFetcher(zipPath),
	}
	go sdn.eventLoop()
	return sdn, nil
}

func (sdn *simpleDirNotifier) Events() <-chan Event {
	return sdn.events
}

func (sdn *simpleDirNotifier) Refresh() {
	sdn.refresh <- struct{}{}
}

func (sdn *simpleDirNotifier) eventLoop() {
	defer close(sdn.events)
	defer close(sdn.refresh)
	if !listDirElements(sdn.log, sdn.fetcher, sdn.events, sdn.done) {
		return
	}
	for {
		select {
		case <-sdn.done:
			return
		case <-sdn.refresh:
			listDirElements(sdn.log, sdn.fetcher, sdn.events, sdn.done)
		}
	}
}

func (sdn *simpleDirNotifier) Close() {
	close(sdn.done)
}

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

	fs.String("d", "", "zettel directory")
	fs.Bool("r", false, "system-wide read-only mode")
	fs.Bool("v", false, "verbose mode")
	fs.Bool("debug", false, "debug mode")
}

func runFunc(*flag.FlagSet) (int, error) {
	var exitCode int
	err := kernel.Main.StartService(kernel.WebService)
	if err != nil {
		exitCode = 1
	}
	kernel.Main.WaitForShutdown()
	return exitCode, err
}








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

	authLog := kern.GetLogger(kernel.AuthService)
	ucLog := kern.GetLogger(kernel.CoreService).WithUser(webSrv)
	ucAuthenticate := usecase.NewAuthenticate(authLog, authManager, authManager, boxManager)
	ucIsAuth := usecase.NewIsAuthenticated(ucLog, webSrv, authManager)
	ucCreateZettel := usecase.NewCreateZettel(ucLog, rtConfig, protectedBoxManager)
	ucGetMeta := usecase.NewGetMeta(protectedBoxManager)
	ucGetAllMeta := usecase.NewGetAllMeta(protectedBoxManager)
	ucGetZettel := usecase.NewGetZettel(protectedBoxManager)
	ucParseZettel := usecase.NewParseZettel(rtConfig, ucGetZettel)
	ucEvaluate := usecase.NewEvaluate(rtConfig, ucGetZettel, ucGetMeta)
	ucListMeta := usecase.NewListMeta(protectedBoxManager)
	ucListRoles := usecase.NewListRole(protectedBoxManager)
	ucListTags := usecase.NewListTags(protectedBoxManager)
	ucZettelContext := usecase.NewZettelContext(protectedBoxManager, rtConfig)
	ucDelete := usecase.NewDeleteZettel(ucLog, protectedBoxManager)
	ucUpdate := usecase.NewUpdateZettel(ucLog, protectedBoxManager)
	ucRename := usecase.NewRenameZettel(ucLog, protectedBoxManager)
	ucUnlinkedRefs := usecase.NewUnlinkedReferences(protectedBoxManager, rtConfig)
	ucRefresh := usecase.NewRefresh(ucLog, protectedBoxManager)

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

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

	webSrv.AddListRoute('h', server.MethodGet, wui.MakeListHTMLMetaHandler(
		ucListMeta, ucListRoles, ucListTags, &ucEvaluate))
	webSrv.AddZettelRoute('h', server.MethodGet, wui.MakeGetHTMLZettelHandler(
		&ucEvaluate, ucGetMeta))
	webSrv.AddListRoute('i', server.MethodGet, wui.MakeGetLoginOutHandler())
	webSrv.AddListRoute('i', server.MethodPost, wui.MakePostLoginHandler(&ucAuthenticate))
	webSrv.AddZettelRoute('i', server.MethodGet, wui.MakeGetInfoHandler(
		ucParseZettel, &ucEvaluate, ucGetMeta, ucGetAllMeta, ucUnlinkedRefs))

	webSrv.AddZettelRoute('k', server.MethodGet, wui.MakeZettelContextHandler(
		ucZettelContext, &ucEvaluate))

	// API
	webSrv.AddListRoute('a', server.MethodPost, a.MakePostLoginHandler(&ucAuthenticate))
	webSrv.AddListRoute('a', server.MethodPut, a.MakeRenewAuthHandler())
	webSrv.AddListRoute('j', server.MethodGet, a.MakeListMetaHandler(ucListMeta))
	webSrv.AddZettelRoute('j', server.MethodGet, a.MakeGetZettelHandler(ucGetZettel))
	webSrv.AddZettelRoute('l', server.MethodGet, a.MakeGetLinksHandler(ucEvaluate))
	webSrv.AddZettelRoute('m', server.MethodGet, a.MakeGetMetaHandler(ucGetMeta))
	webSrv.AddZettelRoute('o', server.MethodGet, a.MakeGetOrderHandler(
		usecase.NewZettelOrder(protectedBoxManager, ucEvaluate)))
	webSrv.AddZettelRoute('p', server.MethodGet, a.MakeGetParsedZettelHandler(ucParseZettel))
	webSrv.AddListRoute('r', server.MethodGet, a.MakeListRoleHandler(ucListRoles))
	webSrv.AddListRoute('t', server.MethodGet, a.MakeListTagsHandler(ucListTags))
	webSrv.AddZettelRoute('u', server.MethodGet, a.MakeListUnlinkedMetaHandler(
		ucGetMeta, ucUnlinkedRefs, &ucEvaluate))
	webSrv.AddListRoute('v', server.MethodPost, a.MakePostEncodeInlinesHandler(ucEvaluate))
	webSrv.AddZettelRoute('v', server.MethodGet, a.MakeGetEvalZettelHandler(ucEvaluate))
	webSrv.AddListRoute('x', server.MethodPost, a.MakePostCommandHandler(&ucIsAuth, &ucRefresh))
	webSrv.AddZettelRoute('x', server.MethodGet, a.MakeZettelContextHandler(ucZettelContext))
	webSrv.AddListRoute('z', server.MethodGet, a.MakeListPlainHandler(ucListMeta))
	webSrv.AddZettelRoute('z', server.MethodGet, a.MakeGetPlainZettelHandler(ucGetZettel))
	if !authManager.IsReadonly() {
		webSrv.AddListRoute('j', server.MethodPost, a.MakePostCreateZettelHandler(&ucCreateZettel))
		webSrv.AddZettelRoute('j', server.MethodPut, a.MakeUpdateZettelHandler(&ucUpdate))
		webSrv.AddZettelRoute('j', server.MethodDelete, a.MakeDeleteZettelHandler(&ucDelete))
		webSrv.AddZettelRoute('j', server.MethodMove, a.MakeRenameZettelHandler(&ucRename))
		webSrv.AddListRoute('z', server.MethodPost, a.MakePostCreatePlainZettelHandler(&ucCreateZettel))
		webSrv.AddZettelRoute('z', server.MethodPut, a.MakeUpdatePlainZettelHandler(&ucUpdate))
		webSrv.AddZettelRoute('z', server.MethodDelete, a.MakeDeleteZettelHandler(&ucDelete))
		webSrv.AddZettelRoute('z', server.MethodMove, a.MakeRenameZettelHandler(&ucRename))
	}

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