# To get started with Dependabot version updates, you'll need to specify which
# package ecosystems to update and where the package manifests are located.
# Please see the documentation for all configuration options:
# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates

version: 2
updates:
  - package-ecosystem: "gomod" # See documentation for possible values
    directory: "/" # Location of package manifests
    schedule:
      interval: "daily"
    rebase-strategy: "disabled"

0.22.0

		zettel.Zettel{
			Meta:    m,
			Content: zettel.NewContent(inp.Src[inp.Pos:]),
		},
		string(m.GetDefault(meta.KeySyntax, meta.DefaultSyntax)),
		nil,
	)

	encdr := encoder.Create(
		api.Encoder(enc),
		&encoder.CreateParameter{Lang: string(m.GetDefault(meta.KeyLang, meta.ValueLangEN))})
	if encdr == nil {
		fmt.Fprintf(os.Stderr, "Unknown format %q\n", enc)
		return 2, nil
	}
	_, err = encdr.WriteZettel(os.Stdout, z)
	if err != nil {
		return 2, err
	}
	fmt.Println()

	return 0, nil
}

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



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

	// API
	webSrv.AddListRoute('a', server.MethodPost, a.MakePostLoginHandler(&ucAuthenticate))
	webSrv.AddListRoute('a', server.MethodPut, a.MakeRenewAuthHandler())
	webSrv.AddZettelRoute('r', server.MethodGet, a.MakeGetReferencesHandler(ucParseZettel, ucGetReferences))
	webSrv.AddListRoute('x', server.MethodGet, a.MakeGetDataHandler(ucVersion))
	webSrv.AddListRoute('x', server.MethodPost, a.MakePostCommandHandler(&ucIsAuth, &ucRefresh))
	webSrv.AddListRoute('z', server.MethodGet, a.MakeQueryHandler(&ucQuery, &ucTagZettel, &ucRoleZettel, &ucReIndex))
	webSrv.AddZettelRoute('z', server.MethodGet, a.MakeGetZettelHandler(ucGetZettel, ucParseZettel, ucEvaluate))
	if !authManager.IsReadonly() {
		webSrv.AddListRoute('z', server.MethodPost, a.MakePostCreateZettelHandler(&ucCreateZettel))
		webSrv.AddZettelRoute('z', server.MethodPut, a.MakeUpdateZettelHandler(&ucUpdate))
		webSrv.AddZettelRoute('z', server.MethodDelete, a.MakeDeleteZettelHandler(&ucDelete))
	}

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

id: 00001004010000
title: Zettelstore startup configuration
role: manual
tags: #configuration #manual #zettelstore
syntax: zmk
created: 20210126175322
modified: 20250627155145

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

  During startup, __X__ is incremented, starting with one, until no key is found.
  This allows you to configure than one box.

  If no ''box-uri-1'' key is given, the overall effect will be the same as if only ''box-uri-1'' was specified with the value ""dir://.zettel"".
  In this case, even a key ''box-uri-2'' will be ignored.
; [!debug-mode|''debug-mode'']
: If set to [[true|00001006030500]], allows to debug the Zettelstore software (mostly used by Zettelstore developers).
  Disables any timeout values of the internal web server and does not send some security-related data.
  Sets [[''log-level''|#log-level]] to ""debug"".
  Enables [[''runtime-profiling''|#runtime-profiling]].

  Do not enable it for a production server.

  Default: ""false""
; [!default-dir-box-type|''default-dir-box-type'']

id: 00001004051000
title: The ''run'' sub-command
role: manual
tags: #command #configuration #manual #zettelstore
syntax: zmk
created: 20210126175322
modified: 20250627160733

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

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

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

  Default is ''./zettel'' (''.\\zettel'' on Windows), where ''.'' denotes the ""current directory"".
; [!debug|''-debug'']
: Allows better debugging of the internal web server by disabling any timeout values.
  You should specify this only as a developer.
  Especially do not enable it for a production server.

  [[https://blog.cloudflare.com/exposing-go-on-the-internet/#timeouts]] contains a good explanation for the usefulness of sensitive timeout values.
; [!p|''-p PORT'']
: Specifies the integer value ''PORT'' as the TCP port, where the Zettelstore web server listens for requests.

  Default: 23123.

  Zettelstore listens only on ''127.0.0.1'', e.g. only requests from the current computer will be processed.
  If you want to listen on network card to process requests from other computer, please use [[''listen-addr''|00001004010000#listen-addr]] of the configuration file as described below.

id: 00001006030000
title: Supported Key Types
role: manual
tags: #manual #meta #reference #zettel #zettelstore
syntax: zmk
created: 20210126175322
modified: 20250115172354

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

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

|=Suffix|Type
| ''-date'' | [[Timestamp|00001006034500]]
| ''-number'' | [[Number|00001006033000]]


| ''-role'' | [[Word|00001006035500]]
| ''-time'' | [[Timestamp|00001006034500]]
| ''-url'' | [[URL|00001006035000]]
| ''-zettel''  | [[Identifier|00001006032000]]
| ''-zid''  | [[Identifier|00001006032000]]
| ''-zids''  | [[IdentifierSet|00001006032500]]
| any other suffix | [[EString|00001006031500]]

id: 00001010000000
title: Security
role: manual
tags: #configuration #manual #security #zettelstore
syntax: zmk
created: 20210126175322
modified: 20250102212014

Your zettel may contain sensitive content.
You probably want to ensure that only authorized persons can read and/or modify them.
Zettelstore ensures this in various ways.

=== Local first
The Zettelstore is designed to run on your local computer.

But you can put a server in front of it, which is able to handle encryption.
Most generic web server software allow this.

To enforce encryption, [[authenticated sessions|00001010040700]] are marked as secure by default.
If you still want to access the Zettelstore remotely without encryption, you must change the startup configuration.
Otherwise, authentication will not work.

* [[Use a server for encryption|00001010090100]]

id: 00001010090100
title: External server to encrypt message transport
role: manual
tags: #configuration #encryption #manual #security #zettelstore
syntax: zmk
created: 20210126175322
modified: 20250701125905

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

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

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

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

id: 00001012053800
title: API: Retrieve references of an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20250415154139
modified: 20250416181257

The [[endpoint|00001012920000]] to retrieve references of a specific zettel is ''/r/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]].

A zettel may contain references to external material, in the form of an URI.
External material may be referenced via Zettelmarkup [[links|00001007040310]], [[inline embedding|00001007040320]], or a [[block transclusion|00001007031100]].
It may also be referenced within the [[metadata|00001006000000]] of a zettel, when a key of [[type|00001006030000]] [[URL|00001006035000]] is given.

https://commonmark.org/
https://xkcd.com/927/
https://github.github.com/gfm/
https://spec.commonmark.org/0.31.2/
https://github.com/yuin/goldmark
```

These examples should make clean, that no duplicates are removed and no sorting takes place.
The client must handle this, e.g.:
```sh
# curl 'http://127.0.0.1:23123/r/00001008010500' | sort -u
https://commonmark.org/
https://github.com/yuin/goldmark
https://github.github.com/gfm/
https://spec.commonmark.org/0.31.2/

id: 00001012920525
title: SHTML Encoding
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
created: 20230316181044
modified: 20250102180003

A zettel representation that is a [[s-expression|00001012930000]], syntactically similar to the [[Sz encoding|00001012920516]], but denotes [[HTML|00001012920510]] semantics.
It is derived from a XML encoding in s-expressions, called [[SXML|https://en.wikipedia.org/wiki/SXML]].

It is (relatively) easy to parse and contains everything to transform it into real HTML.
In contrast to HTML, SHTML is easier to parse and to manipulate.
For example, take a look at the SHTML encoding of this page, which is available via the ""Info"" sub-page of this zettel: 

A list may contain a possibly empty sequence of elements, i.e. lists and / or atoms.
Before the last element of a list of at least two elements, a full stop character (""''.''"", U+002E) signal a pair as the last two elements.
This allows a more space economic storage of data.

An HTML tag like ``< a href="link">Text</a>`` is encoded in SHTML with a list, where the first element is a symbol named a the tag.
The second element is an optional encoding of the tag's attributes.
Further elements are either other tag encodings or a string.
The above tag is encoded as ``(a (@ (href . "link")) "Text")``.
Also possible is to encode the attribute without pairs: ``(a (@ (href "link")) "Text")`` (note the missing full stop character).

id: 00001012931000
title: Encoding of Sz
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
created: 20230403153903
modified: 20250102213403

Zettel in a [[Sz encoding|00001012920516]] are represented as a [[symbolic expression|00001012930000]].
To process these symbolic expressions, you need to know, how a specific part of a zettel is represented by a symbolic expression.

Basically, each part of a zettel is represented as a list, often a nested list.
The first element of that list is always a unique symbol, which denotes that part.
The meaning / semantic of all other elements depend on that symbol.

Either, there are no attributes.
These are specified by the empty list ''()''.
Or there are attributes.
In this case, the first element of the list must be the symbol ''quote'': ''(quote'' ''('' A,,1,, A,,2,, … A,,n,, '')'''')''.

=== Other

A list with ''UNKNOWN'' as its first element signals an internal error during transforming a zettel into the Sz encoding.
It may be ignored, or it may produce an error.

:::syntax
__Unknown__ **=** ''(UNKNOWN'' Object … '')''.
:::

The list may only contain the symbol ''UNKNOWN'', or additionally an unlimited amount of other objects.


Similar, any symbol with the pattern ''**xyz:NOT-FOUND**'', where ''xyz'' is any string, signals an internal error.

id: 00001012931400
title: Encoding of Sz Block Elements
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
created: 20230403161803
modified: 20250317143910

=== ''PARA''
:::syntax
__Paragraph__ **=** ''(PARA'' [[__InlineElement__|00001012931600]] … '')''.
:::
A paragraph is just a list of inline elements.

:::

=== ''ORDERED'', ''UNORDERED'', ''QUOTATION''
These three symbols are specifying different kinds of lists / enumerations: an ordered list, an unordered list, and a quotation list.
Their structure is the same.

:::syntax
__OrderedList__ **=** ''(ORDERED'' [[__Attributes__|00001012931000#attribute]] __ListElement__ … '')''.

__UnorderedList__ **=** ''(UNORDERED'' [[__Attributes__|00001012931000#attribute]] __ListElement__ … '')''.

__QuotationList__ **=** ''(QUOTATION'' [[__Attributes__|00001012931000#attribute]] __ListElement__ … '')''.
:::

:::syntax
__ListElement__ **=** [[__Block__|00001012931000#block]] **|** [[__Inline__|00001012931000#inline]].
:::
A list element is either a block or an inline.
If it is a block, it may contain a nested list.
=== ''DESCRIPTION''
:::syntax
__Description__ **=** ''(DESCRIPTION'' [[__Attributes__|00001012931000#attribute]] __DescriptionTerm__ __DescriptionValues__ __DescriptionTerm__ __DescriptionValues__ … '')''.
:::
A description is a sequence of one or more terms and values.

:::syntax

:::syntax
__ZettelVerbatim__ **=** ''(VERBATIM-ZETTEL'' [[__Attributes__|00001012931000#attribute]] String '')''.
:::
The string contains text that should be treated as (nested) zettel content.

=== ''BLOB''
:::syntax
__BLOB__ **=** ''(BLOB'' [[__Attributes__|00001012931000#attribute]] ''('' [[__InlineElement__|00001012931600]] … '')'' String,,1,, String,,2,, '')''.
:::
A BLOB contains an image in block mode.
The inline elements states some description.
The first string contains the syntax of the image.
The second string contains the actual image.
If the syntax is ""SVG"", then the second string contains the SVG code.
Otherwise the (binary) image data is encoded with base64.

=== ''TRANSCLUDE''
:::syntax
__Transclude__ **=** ''(TRANSCLUDE'' [[__Attributes__|00001012931000#attribute]] [[__Reference__|00001012931900]] [[__InlineElement__|00001012931600]] … '')''.
:::
A transclude list only occurs for a parsed zettel, but not for a evaluated zettel.
Evaluating a zettel also means that all transclusions are resolved.

__Reference__ denotes the zettel to be transcluded.

id: 00001012931600
title: Encoding of Sz Inline Elements
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
created: 20230403161845
modified: 20250313130428

=== ''TEXT''
:::syntax
__Text__ **=** ''(TEXT'' String '')''.
:::
Specifies the string as some text content, including white space characters.

If the string value is empty, it is an inline transclusion.
Otherwise it contains the syntax of an image.

The __InlineElement__ at the end of the list is interpreted as describing text.

=== ''EMBED-BLOB''
:::syntax
__EmbedBLOB__ **=** ''(EMBED-BLOB'' [[__Attributes__|00001012931000#attribute]] String,,1,, String,,2,, '')''.
:::
If used if some processed image has to be embedded inside some inline material.
The first string specifies the syntax of the image content.
The second string contains the image content.
If the syntax is ""SVG"", the image content is not encoded further.
Otherwise a base64 encoding is used.

=== ''CITE''
:::syntax
__CiteBLOB__ **=** ''(CITE'' [[__Attributes__|00001012931000#attribute]] String [[__InlineElement__|00001012931600]] … '')''.
:::
The string contains the citation key.

The string contains text that should be treated as executable code.

:::syntax
__CommentLiteral__ **=** ''(LITERAL-COMMENT'' [[__Attributes__|00001012931000#attribute]] String '')''.
:::
The string contains text that should be treated as an internal comment not to be interpreted further.

:::syntax
__HTMLLiteral__ **=** ''(LITERAL-HTML'' [[__Attributes__|00001012931000#attribute]] String '')''.
:::
The string contains text that should be treated as HTML code.

:::syntax
__InputLiteral__ **=** ''(LITERAL-INPUT'' [[__Attributes__|00001012931000#attribute]] String '')''.
:::
The string contains text that should be treated as input entered by a user.

:::syntax
__MathLiteral__ **=** ''(LITERAL-MATH'' [[__Attributes__|00001012931000#attribute]] String '')''.
:::
The string contains text that should be treated as special code to be interpreted as mathematical formulas.

:::syntax
__OutputLiteral__ **=** ''(LITERAL-OUTPUT'' [[__Attributes__|00001012931000#attribute]] String '')''.
:::
The string contains text that should be treated as computer output to be read by a user.

:::syntax
__ZettelLiteral__ **=** ''(LITERAL-ZETTEL'' [[__Attributes__|00001012931000#attribute]] String '')''.
:::
The string contains text that should be treated as (nested) zettel content.

id: 00001018000000
title: Troubleshooting
role: manual
tags: #manual #zettelstore
syntax: zmk
created: 20211027105921
modified: 20250627130445

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

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

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





=== Working with Zettel Files
* **Problem:** When you delete a zettel file by removing it from the ""disk"", e.g. by dropping it into the trash folder, by dragging into another folder, or by removing it from the command line, Zettelstore sometimes does not detect the change.
  If you access the zettel via Zettelstore, an error is reported.
** **Explanation:** Sometimes, the operating system does not tell Zettelstore about the removed zettel.
   This occurs mostly under MacOS.
** **Solution 1:** If you are running Zettelstore in [[""simple-mode""|00001004051100]] or if you have enabled [[''expert-mode''|00001004020000#expert-mode]], you are allowed to refresh the internal data by selecting ""Refresh"" in the Web User Interface (you can find in the menu ""Lists"").

module zettelstore.de/z

go 1.24

require (
	github.com/fsnotify/fsnotify v1.9.0
	github.com/yuin/goldmark v1.7.12
	golang.org/x/crypto v0.39.0
	golang.org/x/term v0.32.0
	t73f.de/r/sx v0.0.0-20250707071435-95b82f7d24bb
	t73f.de/r/sxwebs v0.0.0-20250707071704-c44197610ee4
	t73f.de/r/webs v0.0.0-20250707071548-227f3e99db55
	t73f.de/r/zero v0.0.0-20250703105709-bb38976d4455
	t73f.de/r/zsc v0.0.0-20250707072124-be388711ad2a
	t73f.de/r/zsx v0.0.0-20250707071920-5e29047e4db7
)

require (
	golang.org/x/sys v0.33.0 // indirect
	golang.org/x/text v0.26.0 // indirect
)

github.com/fsnotify/fsnotify v1.9.0 h1:2Ml+OJNzbYCTzsxtv8vKSFD9PbJjmhYF14k/jKC7S9k=
github.com/fsnotify/fsnotify v1.9.0/go.mod h1:8jBTzvmWwFyi3Pb8djgCCO5IBqzKJ/Jwo8TRcHyHii0=
github.com/yuin/goldmark v1.7.12 h1:YwGP/rrea2/CnCtUHgjuolG/PnMxdQtPMO5PvaE2/nY=
github.com/yuin/goldmark v1.7.12/go.mod h1:ip/1k0VRfGynBgxOz0yCqHrbZXhcjxyuS66Brc7iBKg=
golang.org/x/crypto v0.39.0 h1:SHs+kF4LP+f+p14esP5jAoDpHU8Gu/v9lFRK6IT5imM=
golang.org/x/crypto v0.39.0/go.mod h1:L+Xg3Wf6HoL4Bn4238Z6ft6KfEpN0tJGo53AAPC632U=
golang.org/x/sys v0.33.0 h1:q3i8TbbEz+JRD9ywIRlyRAQbM0qF7hu24q3teo2hbuw=
golang.org/x/sys v0.33.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
golang.org/x/term v0.32.0 h1:DR4lr0TjUs3epypdhTOkMmuF5CDFJ/8pOnbzMZPQ7bg=
golang.org/x/term v0.32.0/go.mod h1:uZG1FhGx848Sqfsq4/DlJr3xGGsYMu/L5GW4abiaEPQ=
golang.org/x/text v0.26.0 h1:P42AVeLghgTYr4+xUnTRKDMqpar+PtX7KWuNQL21L8M=
golang.org/x/text v0.26.0/go.mod h1:QK15LZJUUQVJxhz7wXgxSy/CJaTFjd0G+YLonydOVQA=
t73f.de/r/sx v0.0.0-20250707071435-95b82f7d24bb h1:cYvTOpaJinh/EPB7i8nx7PtT7hniuSP+NZr74P9U+fE=
t73f.de/r/sx v0.0.0-20250707071435-95b82f7d24bb/go.mod h1:uglbFdRHlcpQVVyCNh4Fd7jbKo8alGBCjRp0aZv8IIg=
t73f.de/r/sxwebs v0.0.0-20250707071704-c44197610ee4 h1:WbT8qQAQjqx1S0syci6yWi+YiNQFFYVBkOSfSYIRid4=
t73f.de/r/sxwebs v0.0.0-20250707071704-c44197610ee4/go.mod h1:zSel+qtBHV9NglxDHlFFPwvaetlZh4H0pLyd7OkpkpQ=
t73f.de/r/webs v0.0.0-20250707071548-227f3e99db55 h1:gl4XpbrzrtAFDY+4V9bixLTUruhzEcwvfKiZi1NqJY4=
t73f.de/r/webs v0.0.0-20250707071548-227f3e99db55/go.mod h1:b8/5E5Pe6WSWqh+T+sxLO5ZLiGVkuL5tgh86kx2OAIg=
t73f.de/r/zero v0.0.0-20250703105709-bb38976d4455 h1:TFRPPexX2WrwuF03hC+Be2ONx2bPzMMBlNDn0rk88eI=
t73f.de/r/zero v0.0.0-20250703105709-bb38976d4455/go.mod h1:Ovx7CYsjz45BNuIEMGZfqA7NdQxERydJqUGnOBoQaXQ=
t73f.de/r/zsc v0.0.0-20250707072124-be388711ad2a h1:p12BTQ8TdKZy6GcCRgVINKSeoMz0wBPcNG7ssYvLNrc=
t73f.de/r/zsc v0.0.0-20250707072124-be388711ad2a/go.mod h1:JnkeoahGBxNK0gDcTnAIfDP2rAP33BtnAU1/rCEewC8=
t73f.de/r/zsx v0.0.0-20250707071920-5e29047e4db7 h1:ERxpb1Hqln+NXoZDK6sqjmX3BzeoLO+O64f4bK0B6dk=
t73f.de/r/zsx v0.0.0-20250707071920-5e29047e4db7/go.mod h1:64/AjQ1GnEBoBhXI1D0bDMGDj7JCbtZUTT3WoA7kS0s=

// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

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

import (
	"net/url"
	"strings"


	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"


	"zettelstore.de/z/internal/zettel"
)

// 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   zettel.Content // Original content
	Zid       id.Zid         // Zettel identification.
	InhMeta   *meta.Meta     // Metadata of the zettel, with inherited values.
	BlocksAST BlockSlice     // 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)
}

// BlockNode is the interface that all block nodes must implement.
type BlockNode interface {
	Node
	blockNode()
}

// ItemNode is a node that can occur as a list item.
type ItemNode interface {
	BlockNode
	itemNode()
}

// ItemSlice is a slice of ItemNodes.

type ItemSlice []ItemNode

// DescriptionNode is a node that contains just textual description.
type DescriptionNode interface {
	ItemNode
	descriptionNode()
}

// DescriptionSlice is a slice of DescriptionNodes.
type DescriptionSlice []DescriptionNode

// InlineNode is the interface that all inline nodes must implement.
type InlineNode interface {
	Node


	inlineNode()






}

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


// RefState indicates the state of the reference.
type RefState int


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

// ParseSpacedText returns an inline slice that consists just of test and space node.
// No Zettelmarkup parsing is done. It is typically used to transform the zettel
// description into an inline slice.
func ParseSpacedText(s string) InlineSlice {

	return InlineSlice{&TextNode{Text: NormalizedSpacedText(s)}}
}


// NormalizedSpacedText returns the given string, but normalize multiple spaces to one space.
func NormalizedSpacedText(s string) string { return strings.Join(strings.Fields(s), " ") }

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package ast

import "t73f.de/r/zsx"

// Definition of Block nodes.

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

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

// WalkChildren walks down to the descriptions.
func (bs *BlockSlice) WalkChildren(v Visitor) {
	if bs != nil {
		for _, bn := range *bs {
			Walk(v, bn)
		}
	}
}

// FirstParagraphInlines returns the inline list of the first paragraph that
// contains a inline list.
func (bs BlockSlice) FirstParagraphInlines() InlineSlice {
	for _, bn := range bs {
		pn, ok := bn.(*ParaNode)
		if !ok {
			continue
		}
		if inl := pn.Inlines; len(inl) > 0 {
			return inl
		}
	}
	return nil
}

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

// ParaNode contains just a sequence of inline elements.
// Another name is "paragraph".
type ParaNode struct {
	Inlines InlineSlice
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

// WalkChildren walks down the blocks and the text.
func (rn *RegionNode) WalkChildren(v Visitor) {
	Walk(v, &rn.Blocks)
	Walk(v, &rn.Inlines)
}

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

// HeadingNode stores the heading text and level.
type HeadingNode struct {
	Level    int
	Attrs    zsx.Attributes
	Slug     string      // Heading text, normalized
	Fragment string      // Heading text, suitable to be used as an unique URL fragment
	Inlines  InlineSlice // Heading text, possibly formatted
}

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

// WalkChildren walks the heading text.
func (hn *HeadingNode) WalkChildren(v Visitor) { Walk(v, &hn.Inlines) }

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

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

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

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

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

// NestedListNode specifies a nestable list, either ordered or unordered.
type NestedListNode struct {
	Kind  NestedListKind
	Attrs zsx.Attributes
	Items []ItemSlice
}

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

// Values for ListCode
const (
	_                   NestedListKind = iota
	NestedListOrdered                  // Ordered list.
	NestedListUnordered                // Unordered list.
	NestedListQuote                    // Quote list.
)

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

// WalkChildren walks down the items.
func (ln *NestedListNode) WalkChildren(v Visitor) {
	if items := ln.Items; items != nil {
		for _, item := range items {
			WalkItemSlice(v, item)
		}
	}
}

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

// DescriptionListNode specifies a description list.
type DescriptionListNode struct {
	Attrs        zsx.Attributes
	Descriptions []Description
}

// Description is one element of a description list.
type Description struct {
	Term         InlineSlice
	Descriptions []DescriptionSlice
}

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

// WalkChildren walks down to the descriptions.
func (dn *DescriptionListNode) WalkChildren(v Visitor) {
	if descrs := dn.Descriptions; descrs != nil {
		for i, desc := range descrs {
			if len(desc.Term) > 0 {
				Walk(v, &descrs[i].Term) // Otherwise, changes in desc.Term will not go back into AST
			}
			if dss := desc.Descriptions; dss != nil {
				for _, dns := range dss {
					WalkDescriptionSlice(v, dns)
				}
			}
		}
	}
}

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

// TableNode specifies a full table
type TableNode struct {
	Header TableRow    // The header row
	Align  []Alignment // Default column alignment
	Rows   []TableRow  // The slice of cell rows
}

// TableCell contains the data for one table cell
type TableCell struct {
	Align   Alignment   // Cell alignment
	Inlines InlineSlice // Cell content
}

// TableRow is a slice of cells.
type TableRow []*TableCell

// Alignment specifies text alignment.
// Currently only for tables.
type Alignment int

// Constants for Alignment.
const (
	_            Alignment = iota
	AlignDefault           // Default alignment, inherited
	AlignLeft              // Left alignment
	AlignCenter            // Center the content
	AlignRight             // Right alignment
)

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

// WalkChildren walks down to the cells.
func (tn *TableNode) WalkChildren(v Visitor) {
	if header := tn.Header; header != nil {
		for i := range header {
			Walk(v, header[i]) // Otherwise changes will not go back
		}
	}
	if rows := tn.Rows; rows != nil {
		for _, row := range rows {
			for i := range row {
				Walk(v, &row[i].Inlines) // Otherwise changes will not go back
			}
		}
	}
}

// WalkChildren walks the list of inline elements.
func (cell *TableCell) WalkChildren(v Visitor) {
	Walk(v, &cell.Inlines) // Otherwise changes will not go back
}

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

// TranscludeNode specifies block content from other zettel to embedded in
// current zettel
type TranscludeNode struct {
	Attrs   zsx.Attributes
	Ref     *Reference
	Inlines InlineSlice // Optional text.
}

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

// WalkChildren walks the associated text.
func (tn *TranscludeNode) WalkChildren(v Visitor) { Walk(v, &tn.Inlines) }

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

// BLOBNode contains just binary data that must be interpreted according to
// a syntax.
type BLOBNode struct {
	Attrs       zsx.Attributes
	Description InlineSlice
	Syntax      string
	Blob        []byte
}

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

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

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package ast

import "t73f.de/r/zsx"

// Definitions of inline nodes.

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

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

// WalkChildren walks down to the list.
func (is *InlineSlice) WalkChildren(v Visitor) {
	if is != nil {
		for _, in := range *is {
			Walk(v, in)
		}
	}
}

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

// TextNode just contains some text.
type TextNode struct {
	Text string // The text itself.
}

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

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

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

// BreakNode signals a new line that must / should be interpreted as a new line break.
type BreakNode struct {
	Hard bool // Hard line break?
}

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

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

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

// LinkNode contains the specified link.
type LinkNode struct {
	Attrs   zsx.Attributes // Optional attributes
	Ref     *Reference
	Inlines InlineSlice // The text associated with the link.
}

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

// WalkChildren walks to the link text.
func (ln *LinkNode) WalkChildren(v Visitor) {
	if len(ln.Inlines) > 0 {
		Walk(v, &ln.Inlines)
	}
}

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

// EmbedRefNode contains the specified embedded reference material.
type EmbedRefNode struct {
	Attrs   zsx.Attributes // Optional attributes
	Ref     *Reference     // The reference to be embedded.
	Syntax  string         // Syntax of referenced material, if known
	Inlines InlineSlice    // Optional text associated with the image.
}

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

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

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

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

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

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

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

// CiteNode contains the specified citation.
type CiteNode struct {
	Attrs   zsx.Attributes // Optional attributes
	Key     string         // The citation key
	Inlines InlineSlice    // Optional text associated with the citation.
}

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

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

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

// MarkNode contains the specified merked position.
// It is a BlockNode too, because although it is typically parsed during inline
// mode, it is moved into block mode afterwards.
type MarkNode struct {
	Mark     string      // The mark text itself
	Slug     string      // Slugified form of Mark
	Fragment string      // Unique form of Slug
	Inlines  InlineSlice // Marked inline content
}

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

// WalkChildren does nothing.
func (mn *MarkNode) WalkChildren(v Visitor) {
	if len(mn.Inlines) > 0 {
		Walk(v, &mn.Inlines)
	}
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package ast

import (
	"net/url"
	"strings"

	"t73f.de/r/zsc/api"
	"t73f.de/r/zsc/domain/id"
)

// QueryPrefix is the prefix that denotes a query expression.
const QueryPrefix = api.QueryPrefix

// ParseReference parses a string and returns a reference.
func ParseReference(s string) *Reference {
	if invalidReference(s) {
		return &Reference{URL: nil, Value: s, State: RefStateInvalid}
	}
	if strings.HasPrefix(s, QueryPrefix) {
		return &Reference{URL: nil, Value: s[len(QueryPrefix):], State: RefStateQuery}
	}
	if state, ok := localState(s); ok {
		if state == RefStateBased {
			s = s[1:]
		}
		u, err := url.Parse(s)
		if err == nil {
			return &Reference{URL: u, Value: s, State: state}
		}
	}
	u, err := url.Parse(s)
	if err != nil {
		return &Reference{URL: nil, Value: s, State: RefStateInvalid}
	}
	if !externalURL(u) {
		if _, err = id.Parse(u.Path); err == nil {
			return &Reference{URL: u, Value: s, State: RefStateZettel}
		}
		if u.Path == "" && u.Fragment != "" {
			return &Reference{URL: u, Value: s, State: RefStateSelf}
		}
	}
	return &Reference{URL: u, Value: s, State: RefStateExternal}
}

func invalidReference(s string) bool { return s == "" || s == "00000000000000" }
func externalURL(u *url.URL) bool {
	return u.Scheme != "" || u.Opaque != "" || u.Host != "" || u.User != nil
}

func localState(path string) (RefState, bool) {
	if len(path) > 0 && path[0] == '/' {
		if len(path) > 1 && path[1] == '/' {
			return RefStateBased, true
		}
		return RefStateHosted, true
	}
	if len(path) > 1 && path[0] == '.' {
		if len(path) > 2 && path[1] == '.' && path[2] == '/' {
			return RefStateHosted, true
		}
		return RefStateHosted, path[1] == '/'
	}
	return RefStateInvalid, false
}

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

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

// IsZettel returns true if it is a referencen to a local zettel.
func (r *Reference) IsZettel() bool {
	switch r.State {
	case RefStateZettel, RefStateSelf, RefStateFound, RefStateBroken:
		return true
	}
	return false
}

// IsLocal returns true if reference is local
func (r *Reference) IsLocal() bool {
	return r.State == RefStateHosted || r.State == RefStateBased
}

// IsExternal returns true if it is a referencen to external material.
func (r *Reference) IsExternal() bool { return r.State == RefStateExternal }

//-----------------------------------------------------------------------------
// Copyright (c) 2020-present Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package ast_test

import (
	"testing"

	"zettelstore.de/z/internal/ast"
)

func TestParseReference(t *testing.T) {
	t.Parallel()
	testcases := []struct {
		link string
		err  bool
		exp  string
	}{
		{"", true, ""},
		{"123", false, "123"},
		{",://", true, ""},
	}

	for i, tc := range testcases {
		got := ast.ParseReference(tc.link)
		if got.IsValid() == tc.err {
			t.Errorf(
				"TC=%d, expected parse error of %q: %v, but got %q", i, tc.link, tc.err, got)
		}
		if got.IsValid() && got.String() != tc.exp {
			t.Errorf("TC=%d, Reference of %q is %q, but got %q", i, tc.link, tc.exp, got)
		}
	}
}

func TestReferenceIsZettelMaterial(t *testing.T) {
	t.Parallel()
	testcases := []struct {
		link       string
		isZettel   bool
		isExternal bool
		isLocal    bool
	}{
		{"", false, false, false},
		{"00000000000000", false, false, false},
		{"http://zettelstore.de/z/ast", false, true, false},
		{"12345678901234", true, false, false},
		{"12345678901234#local", true, false, false},
		{"http://12345678901234", false, true, false},
		{"http://zettelstore.de/z/12345678901234", false, true, false},
		{"http://zettelstore.de/12345678901234", false, true, false},
		{"/12345678901234", false, false, true},
		{"//12345678901234", false, false, true},
		{"./12345678901234", false, false, true},
		{"../12345678901234", false, false, true},
		{".../12345678901234", false, true, false},
	}

	for i, tc := range testcases {
		ref := ast.ParseReference(tc.link)
		isZettel := ref.IsZettel()
		if isZettel != tc.isZettel {
			t.Errorf(
				"TC=%d, Reference %q isZettel=%v expected, but got %v",
				i,
				tc.link,
				tc.isZettel,
				isZettel)
		}
		isLocal := ref.IsLocal()
		if isLocal != tc.isLocal {
			t.Errorf(
				"TC=%d, Reference %q isLocal=%v expected, but got %v",
				i,
				tc.link,
				tc.isLocal, isLocal)
		}
		isExternal := ref.IsExternal()
		if isExternal != tc.isExternal {
			t.Errorf(
				"TC=%d, Reference %q isExternal=%v expected, but got %v",
				i,
				tc.link,
				tc.isExternal,
				isExternal)
		}
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2025-present Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2025-present Detlef Stern
//-----------------------------------------------------------------------------

// Package sztrans allows to transform a sz representation of text into an
// abstract syntax tree.
package sztrans

import (
	"fmt"
	"log"

	"t73f.de/r/sx"
	"t73f.de/r/zsc/sz"
	"t73f.de/r/zsx"

	"zettelstore.de/z/internal/ast"
)

type transformer struct{}

// GetBlockSlice returns the sz representations as a AST BlockSlice
func GetBlockSlice(pair *sx.Pair) (ast.BlockSlice, error) {
	if pair == nil {
		return nil, nil
	}
	var t transformer
	if obj := zsx.Walk(&t, pair, nil); !obj.IsNil() {
		if sxn, isNode := obj.(sxNode); isNode {
			if bs, ok := sxn.node.(*ast.BlockSlice); ok {
				return *bs, nil
			}
			return nil, fmt.Errorf("no BlockSlice AST: %T/%v for %v", sxn.node, sxn.node, pair)
		}
		return nil, fmt.Errorf("no AST for %v: %v", pair, obj)
	}
	return nil, fmt.Errorf("error walking %v", pair)
}

func (t *transformer) VisitBefore(pair *sx.Pair, _ *sx.Pair) (sx.Object, bool) {
	if sym, isSymbol := sx.GetSymbol(pair.Car()); isSymbol {
		switch sym {
		case zsx.SymText:
			if p := pair.Tail(); p != nil {
				if s, isString := sx.GetString(p.Car()); isString {
					return sxNode{&ast.TextNode{Text: s.GetValue()}}, true
				}
			}
		case zsx.SymSoft:
			return sxNode{&ast.BreakNode{Hard: false}}, true
		case zsx.SymHard:
			return sxNode{&ast.BreakNode{Hard: true}}, true
		case zsx.SymLiteralCode:
			return handleLiteral(ast.LiteralCode, pair.Tail())
		case zsx.SymLiteralComment:
			return handleLiteral(ast.LiteralComment, pair.Tail())
		case zsx.SymLiteralInput:
			return handleLiteral(ast.LiteralInput, pair.Tail())
		case zsx.SymLiteralMath:
			return handleLiteral(ast.LiteralMath, pair.Tail())
		case zsx.SymLiteralOutput:
			return handleLiteral(ast.LiteralOutput, pair.Tail())
		case zsx.SymThematic:
			return sxNode{&ast.HRuleNode{Attrs: zsx.GetAttributes(pair.Tail().Head())}}, true
		case zsx.SymVerbatimComment:
			return handleVerbatim(ast.VerbatimComment, pair.Tail())
		case zsx.SymVerbatimEval:
			return handleVerbatim(ast.VerbatimEval, pair.Tail())
		case zsx.SymVerbatimHTML:
			return handleVerbatim(ast.VerbatimHTML, pair.Tail())
		case zsx.SymVerbatimMath:
			return handleVerbatim(ast.VerbatimMath, pair.Tail())
		case zsx.SymVerbatimCode:
			return handleVerbatim(ast.VerbatimCode, pair.Tail())
		case zsx.SymVerbatimZettel:
			return handleVerbatim(ast.VerbatimZettel, pair.Tail())
		}
	}
	return sx.Nil(), false
}

func handleLiteral(kind ast.LiteralKind, rest *sx.Pair) (sx.Object, bool) {
	if rest != nil {
		attrs := zsx.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			if s, isString := sx.GetString(curr.Car()); isString {
				return sxNode{&ast.LiteralNode{
					Kind:    kind,
					Attrs:   attrs,
					Content: []byte(s.GetValue())}}, true
			}
		}
	}
	return nil, false
}

func handleVerbatim(kind ast.VerbatimKind, rest *sx.Pair) (sx.Object, bool) {
	if rest != nil {
		attrs := zsx.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			if s, isString := sx.GetString(curr.Car()); isString {
				return sxNode{&ast.VerbatimNode{
					Kind:    kind,
					Attrs:   attrs,
					Content: []byte(s.GetValue()),
				}}, true
			}
		}
	}
	return nil, false
}

func (t *transformer) VisitAfter(pair *sx.Pair, _ *sx.Pair) sx.Object {
	if sym, isSymbol := sx.GetSymbol(pair.Car()); isSymbol {
		switch sym {
		case zsx.SymBlock:
			bns := collectBlocks(pair.Tail())
			return sxNode{&bns}
		case zsx.SymPara:
			return sxNode{&ast.ParaNode{Inlines: collectInlines(pair.Tail())}}
		case zsx.SymHeading:
			return handleHeading(pair.Tail())
		case zsx.SymListOrdered:
			return handleList(ast.NestedListOrdered, pair.Tail())
		case zsx.SymListUnordered:
			return handleList(ast.NestedListUnordered, pair.Tail())
		case zsx.SymListQuote:
			return handleList(ast.NestedListQuote, pair.Tail())
		case zsx.SymDescription:
			return handleDescription(pair.Tail())
		case zsx.SymTable:
			return handleTable(pair.Tail())
		case zsx.SymCell:
			return handleCell(pair.Tail())
		case zsx.SymRegionBlock:
			return handleRegion(ast.RegionSpan, pair.Tail())
		case zsx.SymRegionQuote:
			return handleRegion(ast.RegionQuote, pair.Tail())
		case zsx.SymRegionVerse:
			return handleRegion(ast.RegionVerse, pair.Tail())
		case zsx.SymTransclude:
			return handleTransclude(pair.Tail())
		case zsx.SymBLOB:
			return handleBLOB(pair.Tail())

		case zsx.SymLink:
			return handleLink(pair.Tail())
		case zsx.SymEmbed:
			return handleEmbed(pair.Tail())
		case zsx.SymEmbedBLOB:
			return handleEmbedBLOB(pair.Tail())
		case zsx.SymCite:
			return handleCite(pair.Tail())
		case zsx.SymMark:
			return handleMark(pair.Tail())
		case zsx.SymEndnote:
			return handleEndnote(pair.Tail())
		case zsx.SymFormatDelete:
			return handleFormat(ast.FormatDelete, pair.Tail())
		case zsx.SymFormatEmph:
			return handleFormat(ast.FormatEmph, pair.Tail())
		case zsx.SymFormatInsert:
			return handleFormat(ast.FormatInsert, pair.Tail())
		case zsx.SymFormatMark:
			return handleFormat(ast.FormatMark, pair.Tail())
		case zsx.SymFormatQuote:
			return handleFormat(ast.FormatQuote, pair.Tail())
		case zsx.SymFormatSpan:
			return handleFormat(ast.FormatSpan, pair.Tail())
		case zsx.SymFormatSub:
			return handleFormat(ast.FormatSub, pair.Tail())
		case zsx.SymFormatSuper:
			return handleFormat(ast.FormatSuper, pair.Tail())
		case zsx.SymFormatStrong:
			return handleFormat(ast.FormatStrong, pair.Tail())
		}
		log.Println("MISS", pair)
	}
	return pair
}

func collectBlocks(lst *sx.Pair) (result ast.BlockSlice) {
	for val := range lst.Values() {
		if sxn, isNode := val.(sxNode); isNode {
			if bn, isInline := sxn.node.(ast.BlockNode); isInline {
				result = append(result, bn)
			}
		}
	}
	return result
}

func collectInlines(lst *sx.Pair) (result ast.InlineSlice) {
	for val := range lst.Values() {
		if sxn, isNode := val.(sxNode); isNode {
			if in, isInline := sxn.node.(ast.InlineNode); isInline {
				result = append(result, in)
			}
		}
	}
	return result
}

func handleHeading(rest *sx.Pair) sx.Object {
	if rest != nil {
		if num, isNumber := rest.Car().(sx.Int64); isNumber && num > 0 && num < 6 {
			if curr := rest.Tail(); curr != nil {
				attrs := zsx.GetAttributes(curr.Head())
				if curr = curr.Tail(); curr != nil {
					if sSlug, isSlug := sx.GetString(curr.Car()); isSlug {
						if curr = curr.Tail(); curr != nil {
							if sUniq, isUniq := sx.GetString(curr.Car()); isUniq {
								return sxNode{&ast.HeadingNode{
									Level:    int(num),
									Attrs:    attrs,
									Slug:     sSlug.GetValue(),
									Fragment: sUniq.GetValue(),
									Inlines:  collectInlines(curr.Tail()),
								}}
							}
						}
					}
				}
			}
		}
	}
	log.Println("HEAD", rest)
	return rest
}

func handleList(kind ast.NestedListKind, rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := zsx.GetAttributes(rest.Head())
		return sxNode{&ast.NestedListNode{
			Kind:  kind,
			Items: collectItemSlices(rest.Tail()),
			Attrs: attrs}}
	}
	log.Println("LIST", kind, rest)
	return rest
}

func collectItemSlices(lst *sx.Pair) (result []ast.ItemSlice) {
	for val := range lst.Values() {
		if sxn, isNode := val.(sxNode); isNode {
			if bns, isBlockSlice := sxn.node.(*ast.BlockSlice); isBlockSlice {
				items := make(ast.ItemSlice, len(*bns))
				for i, bn := range *bns {
					if it, ok := bn.(ast.ItemNode); ok {
						items[i] = it
					}
				}
				result = append(result, items)
			}
			if ins, isInline := sxn.node.(*ast.InlineSlice); isInline {
				items := make(ast.ItemSlice, len(*ins))
				for i, bn := range *ins {
					if it, ok := bn.(ast.ItemNode); ok {
						items[i] = it
					}
				}
				result = append(result, items)
			}
		}
	}
	return result
}

func handleDescription(rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := zsx.GetAttributes(rest.Head())
		var descs []ast.Description
		for curr := rest.Tail(); curr != nil; {
			term := collectInlines(curr.Head())
			curr = curr.Tail()
			if curr == nil {
				descr := ast.Description{Term: term, Descriptions: nil}
				descs = append(descs, descr)
				break
			}

			car := curr.Car()
			if sx.IsNil(car) {
				descs = append(descs, ast.Description{Term: term, Descriptions: nil})
				curr = curr.Tail()
				continue
			}

			sxn, isNode := car.(sxNode)
			if !isNode {
				descs = nil
				break
			}
			blocks, isBlocks := sxn.node.(*ast.BlockSlice)
			if !isBlocks {
				descs = nil
				break
			}

			descSlice := make([]ast.DescriptionSlice, 0, len(*blocks))
			for _, bn := range *blocks {
				bns, isBns := bn.(*ast.BlockSlice)
				if !isBns {
					continue
				}
				ds := make(ast.DescriptionSlice, 0, len(*bns))
				for _, b := range *bns {
					if defNode, isDef := b.(ast.DescriptionNode); isDef {
						ds = append(ds, defNode)
					}
				}
				descSlice = append(descSlice, ds)
			}

			descr := ast.Description{Term: term, Descriptions: descSlice}
			descs = append(descs, descr)

			curr = curr.Tail()
		}
		if len(descs) > 0 {
			return sxNode{&ast.DescriptionListNode{
				Attrs:        attrs,
				Descriptions: descs,
			}}
		}
	}
	log.Println("DESC", rest)
	return rest
}

func handleTable(rest *sx.Pair) sx.Object {
	if rest != nil {
		header := collectRow(rest.Head())
		cols := len(header)

		var rows []ast.TableRow
		for curr := range rest.Tail().Pairs() {
			row := collectRow(curr.Head())
			rows = append(rows, row)
			cols = max(cols, len(row))
		}
		align := make([]ast.Alignment, cols)
		for i := range cols {
			align[i] = ast.AlignDefault
		}

		return sxNode{&ast.TableNode{
			Header: header,
			Align:  align,
			Rows:   rows,
		}}
	}
	log.Println("TABL", rest)
	return rest
}

func collectRow(lst *sx.Pair) (row ast.TableRow) {
	for curr := range lst.Values() {
		if sxn, isNode := curr.(sxNode); isNode {
			if cell, isCell := sxn.node.(*ast.TableCell); isCell {
				row = append(row, cell)
			}
		}
	}
	return row
}

func handleCell(rest *sx.Pair) sx.Object {
	if rest != nil {
		align := ast.AlignDefault
		if alignPair := rest.Head().Assoc(zsx.SymAttrAlign); alignPair != nil {
			if alignValue := alignPair.Cdr(); zsx.AttrAlignCenter.IsEqual(alignValue) {
				align = ast.AlignCenter
			} else if zsx.AttrAlignLeft.IsEqual(alignValue) {
				align = ast.AlignLeft
			} else if zsx.AttrAlignRight.IsEqual(alignValue) {
				align = ast.AlignRight
			}
		}
		return sxNode{&ast.TableCell{
			Align:   align,
			Inlines: collectInlines(rest.Tail()),
		}}
	}
	log.Println("CELL", rest)
	return rest
}

func handleRegion(kind ast.RegionKind, rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := zsx.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			if blockList := curr.Head(); blockList != nil {
				return sxNode{&ast.RegionNode{
					Kind:    kind,
					Attrs:   attrs,
					Blocks:  collectBlocks(blockList),
					Inlines: collectInlines(curr.Tail()),
				}}
			}
		}
	}
	log.Println("REGI", rest)
	return rest
}

func handleTransclude(rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := zsx.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			ref := collectReference(curr.Head())
			return sxNode{&ast.TranscludeNode{
				Attrs:   attrs,
				Ref:     ref,
				Inlines: collectInlines(curr.Tail()),
			}}
		}
	}
	log.Println("TRAN", rest)
	return rest
}

func handleBLOB(rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := zsx.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			ins := collectInlines(curr.Head())
			if curr = curr.Tail(); curr != nil {
				if syntax, isString := sx.GetString(curr.Car()); isString {
					if curr = curr.Tail(); curr != nil {
						if blob, isBlob := sx.GetString(curr.Car()); isBlob {
							return sxNode{&ast.BLOBNode{
								Attrs:       attrs,
								Description: ins,
								Syntax:      syntax.GetValue(),
								Blob:        []byte(blob.GetValue()),
							}}

						}
					}
				}
			}
		}
	}
	log.Println("BLOB", rest)
	return rest
}

var mapRefState = map[*sx.Symbol]ast.RefState{
	zsx.SymRefStateInvalid:  ast.RefStateInvalid,
	sz.SymRefStateZettel:    ast.RefStateZettel,
	zsx.SymRefStateSelf:     ast.RefStateSelf,
	sz.SymRefStateFound:     ast.RefStateFound,
	sz.SymRefStateBroken:    ast.RefStateBroken,
	zsx.SymRefStateHosted:   ast.RefStateHosted,
	sz.SymRefStateBased:     ast.RefStateBased,
	sz.SymRefStateQuery:     ast.RefStateQuery,
	zsx.SymRefStateExternal: ast.RefStateExternal,
}

func handleLink(rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := zsx.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			if szref := curr.Head(); szref != nil {
				if stateSym, isSym := sx.GetSymbol(szref.Car()); isSym {
					refval, isString := sx.GetString(szref.Cdr())
					if !isString {
						refval, isString = sx.GetString(szref.Tail().Car())
					}
					if isString {
						ref := ast.ParseReference(refval.GetValue())
						ref.State = mapRefState[stateSym]
						ins := collectInlines(curr.Tail())
						return sxNode{&ast.LinkNode{
							Attrs:   attrs,
							Ref:     ref,
							Inlines: ins,
						}}
					}
				}
			}
		}
	}
	log.Println("LINK", rest)
	return rest
}

func handleEmbed(rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := zsx.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			if ref := collectReference(curr.Head()); ref != nil {
				if curr = curr.Tail(); curr != nil {
					if syntax, isString := sx.GetString(curr.Car()); isString {
						return sxNode{&ast.EmbedRefNode{
							Attrs:   attrs,
							Ref:     ref,
							Syntax:  syntax.GetValue(),
							Inlines: collectInlines(curr.Tail()),
						}}
					}
				}
			}
		}
	}
	log.Println("EMBE", rest)
	return rest
}

func handleEmbedBLOB(rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := zsx.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			if syntax, isSyntax := sx.GetString(curr.Car()); isSyntax {
				if curr = curr.Tail(); curr != nil {
					if content, isContent := sx.GetString(curr.Car()); isContent {
						return sxNode{&ast.EmbedBLOBNode{
							Attrs:   attrs,
							Syntax:  syntax.GetValue(),
							Blob:    []byte(content.GetValue()),
							Inlines: collectInlines(curr.Tail()),
						}}
					}
				}
			}
		}
	}
	log.Println("EMBL", rest)
	return rest
}

func collectReference(pair *sx.Pair) *ast.Reference {
	if pair != nil {
		if sym, isSymbol := sx.GetSymbol(pair.Car()); isSymbol {
			if next := pair.Tail(); next != nil {
				if sRef, isString := sx.GetString(next.Car()); isString {
					ref := ast.ParseReference(sRef.GetValue())
					switch sym {
					case zsx.SymRefStateInvalid:
						ref.State = ast.RefStateInvalid
					case sz.SymRefStateZettel:
						ref.State = ast.RefStateZettel
					case zsx.SymRefStateSelf:
						ref.State = ast.RefStateSelf
					case sz.SymRefStateFound:
						ref.State = ast.RefStateFound
					case sz.SymRefStateBroken:
						ref.State = ast.RefStateBroken
					case zsx.SymRefStateHosted:
						ref.State = ast.RefStateHosted
					case sz.SymRefStateBased:
						ref.State = ast.RefStateBased
					case sz.SymRefStateQuery:
						ref.State = ast.RefStateQuery
					case zsx.SymRefStateExternal:
						ref.State = ast.RefStateExternal
					}
					return ref
				}
			}
		}
	}
	return nil
}

func handleCite(rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := zsx.GetAttributes(rest.Head())
		if curr := rest.Tail(); curr != nil {
			if sKey, isString := sx.GetString(curr.Car()); isString {
				return sxNode{&ast.CiteNode{
					Attrs:   attrs,
					Key:     sKey.GetValue(),
					Inlines: collectInlines(curr.Tail()),
				}}
			}
		}
	}
	log.Println("CITE", rest)
	return rest
}

func handleMark(rest *sx.Pair) sx.Object {
	if rest != nil {
		if sMark, isMarkS := sx.GetString(rest.Car()); isMarkS {
			if curr := rest.Tail(); curr != nil {
				if sSlug, isSlug := sx.GetString(curr.Car()); isSlug {
					if curr = curr.Tail(); curr != nil {
						if sUniq, isUniq := sx.GetString(curr.Car()); isUniq {
							return sxNode{&ast.MarkNode{
								Mark:     sMark.GetValue(),
								Slug:     sSlug.GetValue(),
								Fragment: sUniq.GetValue(),
								Inlines:  collectInlines(curr.Tail()),
							}}
						}
					}
				}
			}
		}
	}
	log.Println("MARK", rest)
	return rest
}

func handleEndnote(rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := zsx.GetAttributes(rest.Head())
		return sxNode{&ast.FootnoteNode{
			Attrs:   attrs,
			Inlines: collectInlines(rest.Tail()),
		}}
	}
	log.Println("ENDN", rest)
	return rest
}

func handleFormat(kind ast.FormatKind, rest *sx.Pair) sx.Object {
	if rest != nil {
		attrs := zsx.GetAttributes(rest.Head())
		return sxNode{&ast.FormatNode{
			Kind:    kind,
			Attrs:   attrs,
			Inlines: collectInlines(rest.Tail()),
		}}
	}
	log.Println("FORM", kind, rest)
	return rest
}

type sxNode struct {
	node ast.Node
}

func (sxNode) IsNil() bool        { return false }
func (sxNode) IsAtom() bool       { return true }
func (n sxNode) String() string   { return fmt.Sprintf("%T/%v", n.node, n.node) }
func (n sxNode) GoString() string { return n.String() }
func (n sxNode) IsEqual(other sx.Object) bool {
	return n.String() == other.String()
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

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 {
		Walk(v, in)
	}
}

// WalkDescriptionSlice traverses an item slice.
func WalkDescriptionSlice(v Visitor, dns DescriptionSlice) {
	for _, dn := range dns {
		Walk(v, dn)
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2021-present Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

package ast_test

import (
	"testing"

	"t73f.de/r/zsx"

	"zettelstore.de/z/internal/ast"
)

func BenchmarkWalk(b *testing.B) {
	root := ast.BlockSlice{
		&ast.HeadingNode{
			Inlines: ast.InlineSlice{&ast.TextNode{Text: "A Simple Heading"}},
		},
		&ast.ParaNode{
			Inlines: ast.InlineSlice{&ast.TextNode{Text: "This is the introduction."}},
		},
		&ast.NestedListNode{
			Kind: ast.NestedListUnordered,
			Items: []ast.ItemSlice{
				[]ast.ItemNode{
					&ast.ParaNode{
						Inlines: ast.InlineSlice{&ast.TextNode{Text: "Item 1"}},
					},
				},
				[]ast.ItemNode{
					&ast.ParaNode{
						Inlines: ast.InlineSlice{&ast.TextNode{Text: "Item 2"}},
					},
				},
			},
		},
		&ast.ParaNode{
			Inlines: ast.InlineSlice{&ast.TextNode{Text: "This is some intermediate text."}},
		},
		ast.CreateParaNode(
			&ast.FormatNode{
				Kind: ast.FormatEmph,
				Attrs: zsx.Attributes(map[string]string{
					"":      "class",
					"color": "green",
				}),
				Inlines: ast.InlineSlice{&ast.TextNode{Text: "This is some emphasized text."}},
			},
			&ast.TextNode{Text: " "},
			&ast.LinkNode{
				Ref:     &ast.Reference{Value: "http://zettelstore.de"},
				Inlines: ast.InlineSlice{&ast.TextNode{Text: "URL text."}},
			},
		),
	}
	v := benchVisitor{}

	for b.Loop() {
		ast.Walk(&v, &root)
	}
}

type benchVisitor struct{}

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

;;; obligations under this license.
;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

`(@@@@
(html ,@(if lang `((@ (lang ,lang))))
(head
  (meta (@ (charset "utf-8")))
  (meta (@ (name "viewport") (content "width=device-width, initial-scale=1.0")))
  (meta (@ (name "generator") (content "Zettelstore")))
  (meta (@ (name "format-detection") (content "telephone=no")))
  ,@META-HEADER
  (link (@ (rel "stylesheet") (href ,css-base-url)))
  (link (@ (rel "stylesheet") (href ,css-user-url)))
  ,@(ROLE-DEFAULT-meta (current-frame))
  ,@(let* ((frame (current-frame))(rem (resolve-symbol 'ROLE-EXTRA-meta frame))) (if (defined? rem) (rem frame)))
  (title ,title))
(body
  (nav (@ (class "zs-menu"))
    (a (@ (href ,home-url)) "Home")
    ,@(if with-auth
      `((div (@ (class "zs-dropdown"))
        (button "User")
        (nav (@ (class "zs-dropdown-content"))
          ,@(if user-is-valid
            `((a (@ (href ,user-zettel-url)) ,user-ident)
              (a (@ (href ,logout-url)) "Logout"))
            `((a (@ (href ,login-url)) "Login"))
          )
      )))
    )
    (div (@ (class "zs-dropdown"))
      (button "Lists")
      (nav (@ (class "zs-dropdown-content"))
        ,@list-urls
        ,@(if (symbol-bound? 'refresh-url) `((a (@ (href ,refresh-url)) "Refresh")))
    ))
    ,@(if new-zettel-links
      `((div (@ (class "zs-dropdown"))
        (button "New")
        (nav (@ (class "zs-dropdown-content"))
          ,@(map wui-link new-zettel-links)
       )))
    )
    (search (form (@ (action ,search-url))
      (input (@ (type "search") (inputmode "search") (name ,query-key-query)
                (title "General search field, with same behaviour as search field in search result list")
                (placeholder "Search..") (dir "auto")))))
  )
  (main (@ (class "content")) ,DETAIL)
  ,@(if FOOTER `((footer (hr) ,@FOOTER)))
  ,@(if debug-mode '((div (b "WARNING: Debug mode is enabled. DO NOT USE IN PRODUCTION!"))))
)))

		zettel.NewContent(contentDependencies)},
	id.ZidBaseTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Base HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20230510155100",
			meta.KeyModified:   "20250623131400",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentBaseSxn)},
	id.ZidLoginTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Login Form HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20200804111624",
			meta.KeyModified:   "20240219145200",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentLoginSxn)},
	id.ZidZettelTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Zettel HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20230510155300",
			meta.KeyModified:   "20250626113800",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentZettelSxn)},
	id.ZidInfoTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Info HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20200804111624",
			meta.KeyModified:   "20250624160000",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentInfoSxn)},
	id.ZidFormTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Form HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20200804111624",
			meta.KeyModified:   "20250612180300",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentFormSxn)},
	id.ZidDeleteTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Delete HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20200804111624",
			meta.KeyModified:   "20250612180200",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentDeleteSxn)},
	id.ZidListTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore List Zettel HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20230704122100",
			meta.KeyModified:   "20250612180200",
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentListZettelSxn)},
	id.ZidErrorTemplate: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Error HTML Template",
			meta.KeyRole:       meta.ValueRoleConfiguration,

		zettel.NewContent(contentStartCodeSxn)},
	id.ZidSxnBase: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Sxn Base Code",
			meta.KeyRole:       meta.ValueRoleConfiguration,
			meta.KeySyntax:     meta.ValueSyntaxSxn,
			meta.KeyCreated:    "20230619132800",
			meta.KeyModified:   "20250624200200",
			meta.KeyReadOnly:   meta.ValueTrue,
			meta.KeyVisibility: meta.ValueVisibilityExpert,
		},
		zettel.NewContent(contentBaseCodeSxn)},
	id.ZidBaseCSS: {
		constHeader{
			meta.KeyTitle:      "Zettelstore Base CSS",

;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

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

;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

`(article
  (header (h1 ,heading))
  (form (@ (action ,form-action-url) (method "POST") (enctype "multipart/form-data"))
  (div
    (label (@ (for "zs-title")) "Title " (a (@ (title "Main heading of this zettel.")) (@H "ⓘ")))
    (input (@ (class "zs-input") (type "text") (id "zs-title") (name "title")
              (title "Title of this zettel")
              (placeholder "Title..") (value ,meta-title) (dir "auto") (autofocus))))
  (div
    (label (@ (for "zs-role")) "Role " (a (@ (title "One word, without spaces, to set the main role of this zettel.")) (@H "ⓘ")))
    (input (@ (class "zs-input") (type "text") (pattern "\\w*") (id "zs-role") (name "role")
              (title "One word, letters and digits, but no spaces, to set the main role of the zettel.")
              (placeholder "role..") (value ,meta-role) (dir "auto")
      ,@(if role-data '((list "zs-role-data")))
    ))
    ,@(wui-datalist "zs-role-data" role-data)
  )
  (div
    (label (@ (for "zs-tags")) "Tags " (a (@ (title "Tags must begin with an '#' sign. They are separated by spaces.")) (@H "ⓘ")))
    (input (@ (class "zs-input") (type "text") (id "zs-tags") (name "tags")
              (title "Tags/keywords to categorize the zettel. Each tags is a word that begins with a '#' character; they are separated by spaces")
              (placeholder "#tag") (value ,meta-tags) (dir "auto"))))
  (div
    (label (@ (for "zs-meta")) "Metadata " (a (@ (title "Other metadata for this zettel. Each line contains a key/value pair, separated by a colon ':'.")) (@H "ⓘ")))
    (textarea (@ (class "zs-input") (id "zs-meta") (name "meta") (rows "4")
                 (title "Additional metadata about the zettel")
                 (placeholder "metakey: metavalue") (dir "auto")) ,meta))
  (div
    (label (@ (for "zs-syntax")) "Syntax " (a (@ (title "Syntax of zettel content below, one word. Typically 'zmk' (for zettelmarkup).")) (@H "ⓘ")))
    (input (@ (class "zs-input") (type "text") (pattern "\\w*") (id "zs-syntax") (name "syntax")
              (title "Syntax/format of zettel content below, one word, letters and digits, no spaces.")
              (placeholder "syntax..") (value ,meta-syntax) (dir "auto")
      ,@(if syntax-data '((list "zs-syntax-data")))
    ))
    ,@(wui-datalist "zs-syntax-data" syntax-data)
  )
  ,@(if (symbol-bound? 'content)
    `((div
      (label (@ (for "zs-content")) "Content " (a (@ (title "Content for this zettel, according to above syntax.")) (@H "ⓘ")))
      (textarea (@ (class "zs-input zs-content") (id "zs-content") (name "content") (rows "20")
                   (title "Zettel content, according to the given syntax")
                   (placeholder "Zettel content..") (dir "auto")) ,content)
    ))
  )
  (div
    (input (@ (class "zs-primary") (type "submit") (value "Submit")))
    (input (@ (class "zs-secondary") (type "submit") (value "Save") (formaction "?save")))
    (input (@ (class "zs-upload") (type "file") (id "zs-file") (name "file")))
  ))
)

;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

`(article
  (header (h1 "Information for Zettel " ,zid)
    (p
      (a (@ (href ,web-url)) "Web")
      ,@(if (symbol-bound? 'edit-url) `((@H " · ") (a (@ (href ,edit-url)) "Edit")))
      (@H " · ") (a (@ (href ,context-full-url)) "Full Context")
      ,@(if (symbol-bound? 'thread-query-url)
            `((@H " · [")  (a (@ (href ,thread-query-url)) "Thread")
              ,@(if (symbol-bound? 'folge-query-url) `((@H ", ") (a (@ (href ,folge-query-url)) "Folge")))
              ,@(if (symbol-bound? 'sequel-query-url) `((@H ", ") (a (@ (href ,sequel-query-url)) "Sequel")))
              (@H "]")))
      ,@(ROLE-DEFAULT-actions (current-frame))
      ,@(let* ((frame (current-frame))(rea (resolve-symbol 'ROLE-EXTRA-actions frame))) (if (defined? rea) (rea frame)))
      ,@(if (symbol-bound? 'reindex-url) `((@H " · ") (a (@ (href ,reindex-url)) "Reindex")))
      ,@(if (symbol-bound? 'delete-url) `((@H " · ") (a (@ (href ,delete-url)) "Delete")))
    )
  )
  (h2 "Interpreted Metadata")
  (table ,@(map wui-info-meta-table-row metadata))
  (h2 "References")
  ,@(if local-links `((h3 "Local")    (ul ,@(map wui-local-link local-links)))) 
  ,@(if query-links `((h3 "Queries")  (ul ,@(map wui-item-link query-links))))
  ,@(if ext-links   `((h3 "External") (ul ,@(map wui-item-popup-link ext-links))))
  (h3 "Unlinked")
  ,@unlinked-content
  (form
    (label (@ (for "phrase")) "Search Phrase")
    (input (@ (class "zs-input") (type "text") (id "phrase") (name ,query-key-phrase) (placeholder "Phrase..") (value ,phrase)))
  )
  (h2 "Parts and encodings")
  ,(wui-enc-matrix enc-eval)
  (h3 "Parsed (not evaluated)")
  ,(wui-enc-matrix enc-parsed)
  ,@(if shadow-links
    `((h2 "Shadowed Boxes")

;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

`(article
  (header (h1 ,heading))
  (search (form (@ (action ,search-url))
    (input (@ (class "zs-input") (type "search") (inputmode "search") (name ,query-key-query)
              (title "Contains the search that leads to the list below. You're allowed to modify it")
              (placeholder "Search..") (value ,query-value) (dir "auto")))))
  ,@(if (symbol-bound? 'tag-zettel)
     `((p (@ (class "zs-meta-zettel")) "Tag zettel: " ,@tag-zettel))
    )
  ,@(if (symbol-bound? 'create-tag-zettel)
     `((p (@ (class "zs-meta-zettel")) "Create tag zettel: " ,@create-tag-zettel))
    )
  ,@(if (symbol-bound? 'role-zettel)
     `((p (@ (class "zs-meta-zettel")) "Role zettel: " ,@role-zettel))
    )
  ,@(if (symbol-bound? 'create-role-zettel)
     `((p (@ (class "zs-meta-zettel")) "Create role zettel: " ,@create-role-zettel))
    )
  ,@content
  ,@endnotes
  (form (@ (action ,(if (symbol-bound? 'create-url) create-url)))
      ,(if (symbol-bound? 'data-url)
          `(@L "Other encodings"
               ,(if (> num-entries 3) `(@L " of these " ,num-entries " entries: ") ": ")
               (a (@ (href ,data-url)) "data")
               ", "
               (a (@ (href ,plain-url)) "plain")
           )
      )
      ,@(if (symbol-bound? 'create-url)
        `((input (@ (type "hidden") (name ,query-key-query) (value ,query-value)))
          (input (@ (type "hidden") (name ,query-key-seed) (value ,seed)))
          (input (@ (class "zs-primary") (type "submit") (value "Save As Zettel")))
        )
      )
  )
)

;;;
;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

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

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

;; wui-info-meta-table-row takes a pair and translates it into a HTML table row
;; with two columns.
(defun wui-info-meta-table-row (p)
    `(tr (td (@ (class zs-info-meta-key)) ,(car p)) (td (@ (class zs-info-meta-value)) ,(cdr p))))




;; wui-local-link translates a local link into HTML.
(defun wui-local-link (l) `(li (a (@ (href ,l )) ,l)))

;; wui-link takes a link (title . url) and returns a HTML reference.
(defun wui-link (q) `(a (@ (href ,(cdr q))) ,(car q)))

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

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

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

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

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

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

;; wui-meta-desc returns a HTML description list made from the list of pairs
;; given.

         (lambda (row) `(tr (th ,(car row)) ,@(map wui-tdata-link (cdr row))))
         matrix)))

;; wui-optional-link puts the text into a link, if symbol is defined. Otherwise just return the text
(defun wui-optional-link (text url-sym)
    (let ((url (resolve-symbol url-sym)))
         (if (defined? url)
             `(a (@ (href ,(resolve-symbol url-sym))) ,text)
             text)))

;; CSS-ROLE-map is a mapping (pair list, assoc list) of role names to zettel
;; identifier. It is used in the base template to update the metadata of the
;; HTML page to include some role specific CSS code.
;; Referenced in function "ROLE-DEFAULT-meta".
(defvar CSS-ROLE-map '())

;; ROLE-DEFAULT-meta returns some metadata for the base template. Any role
;; specific code should include the returned list of this function.
(defun ROLE-DEFAULT-meta (frame)
    `(,@(let* ((meta-role (resolve-symbol 'meta-role frame))
               (entry (assoc CSS-ROLE-map meta-role)))
              (if (pair? entry)
                  `((link (@ (rel "stylesheet") (href ,(zid-content-path (cdr entry))))))
              )
        )
    )
)

;; ACTION-SEPARATOR defines a HTML value that separates actions links.
(defvar ACTION-SEPARATOR '(@H " · "))

;; ROLE-DEFAULT-actions returns the default text for actions.
(defun ROLE-DEFAULT-actions (frame)
    `(,@(let ((copy-url (resolve-symbol 'copy-url frame)))
             (if (defined? copy-url) `((@H " · ") (a (@ (href ,copy-url)) "Copy"))))
      ,@(let ((sequel-url (resolve-symbol 'sequel-url frame)))
             (if (defined? sequel-url) `((@H " · ") (a (@ (href ,sequel-url)) "Sequel"))))
      ,@(let ((folge-url (resolve-symbol 'folge-url frame)))
             (if (defined? folge-url) `((@H " · ") (a (@ (href ,folge-url)) "Folge"))))
    )
)

;; ROLE-tag-actions returns an additional action "Zettel" for zettel with role "tag".
(defun ROLE-tag-actions (frame)
    `(,@(let ((title (resolve-symbol 'title frame)))
             (if (and (defined? title) title)
                 `(,ACTION-SEPARATOR (a (@ (href ,(query->url (concat "tags:" title)))) "Zettel"))
             )
        )
    )
)

;; ROLE-role-actions returns an additional action "Zettel" for zettel with role "role".
(defun ROLE-role-actions (frame)
    `(,@(let ((title (resolve-symbol 'title frame)))
             (if (and (defined? title) title)
                 `(,ACTION-SEPARATOR (a (@ (href ,(query->url (concat "role:" title)))) "Zettel"))
             )
        )
    )
)

;; ROLE-DEFAULT-heading returns the default text for headings, below the
;; references of a zettel. In most cases it should be called from an

;;; SPDX-License-Identifier: EUPL-1.2
;;; SPDX-FileCopyrightText: 2023-present Detlef Stern
;;;----------------------------------------------------------------------------

`(article
  (header
    (h1 ,heading)
    (div (@ (class "zs-meta"))
      ,@(if (symbol-bound? 'edit-url) `((a (@ (href ,edit-url)) "Edit") (@H " · ")))
      ,zid (@H " · ")
      (a (@ (href ,info-url)) "Info") (@H " · ")
      "(" ,@(if (symbol-bound? 'role-url) `((a (@ (href ,role-url)) ,meta-role)))
          ,@(if (and (symbol-bound? 'folge-role-url) (symbol-bound? 'meta-folge-role))
                `((@H " → ") (a (@ (href ,folge-role-url)) ,meta-folge-role)))
      ")"
      ,@(if tag-refs `((@H " · ") ,@tag-refs))
      (@H " · ") (a (@ (href ,context-url)) "Context")
      ,@(if (symbol-bound? 'thread-query-url) `((@H " · ")  (a (@ (href ,thread-query-url)) "Thread")))
      ,@(ROLE-DEFAULT-actions (current-frame))
      ,@(let* ((frame (current-frame))(rea (resolve-symbol 'ROLE-EXTRA-actions frame))) (if (defined? rea) (rea frame)))
      ,@(if superior-refs `((br) "Superior: " ,superior-refs))
      ,@(if prequel-refs `((br) ,(wui-optional-link "Prequel" 'sequel-query-url) ": " ,prequel-refs))
      ,@(if precursor-refs `((br) ,(wui-optional-link "Precursor" 'folge-query-url) ": " ,precursor-refs))
      ,@(ROLE-DEFAULT-heading (current-frame))
      ,@(let* ((frame (current-frame))(reh (resolve-symbol 'ROLE-EXTRA-heading frame))) (if (defined? reh) (reh frame)))
    )
  )
  ,@content
  ,endnotes
  ,@(if (or folge-links sequel-links back-links subordinate-links)
    `((nav
      ,@(if folge-links
            `((details (@ (,folge-open))
                       (summary ,(wui-optional-link "Folgezettel" 'folge-query-url))
                       (ul ,@(map wui-item-link folge-links)))))
      ,@(if sequel-links
            `((details (@ (,sequel-open))
                       (summary ,(wui-optional-link "Sequel" 'sequel-query-url))
                       (ul ,@(map wui-item-link sequel-links)))))
      ,@(if subordinate-links `((details (@ (,subordinate-open)) (summary "Subordinates") (ul ,@(map wui-item-link subordinate-links)))))
      ,@(if back-links `((details (@ (,back-open)) (summary "Incoming") (ul ,@(map wui-item-link back-links)))))
     ))
  )
)

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

package manager

import (
	"strings"


	zerostrings "t73f.de/r/zero/strings"
	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/id/idset"



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

type collectData struct {
	refs  *idset.Set
	words store.WordSet
	urls  store.WordSet
}

func (data *collectData) initialize() {
	data.refs = idset.New()
	data.words = store.NewWordSet()
	data.urls = store.NewWordSet()
}

func collectZettelIndexData(zn *ast.ZettelNode, data *collectData) {
	ast.Walk(data, &zn.BlocksAST)
}

func (data *collectData) Visit(node ast.Node) ast.Visitor {

	switch n := node.(type) {
	case *ast.VerbatimNode:
		data.addText(string(n.Content))
	case *ast.TranscludeNode:


		data.addRef(n.Ref)
	case *ast.TextNode:


		data.addText(n.Text)
	case *ast.LinkNode:

		data.addRef(n.Ref)
	case *ast.EmbedRefNode:

		data.addRef(n.Ref)
	case *ast.CiteNode:

		data.addText(n.Key)
	case *ast.LiteralNode:

		data.addText(string(n.Content))
	}

	return data












}

func (data *collectData) addText(s string) {
	for _, word := range zerostrings.NormalizeWords(s) {
		data.words.Add(word)
	}
}

func (data *collectData) addRef(ref *ast.Reference) {
	if ref == nil {
		return
	}
	if ref.IsExternal() {
		data.urls.Add(strings.ToLower(ref.Value))
	}
	if !ref.IsZettel() {
		return
	}
	if zid, err := id.Parse(ref.URL.Path); err == nil {
		data.refs.Add(zid)
	}
}

	return true
}

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

	}

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

// Package collect provides functions to collect items from a syntax tree.
package collect

import (
	"iter"

	"zettelstore.de/z/internal/ast"

)

type refYielder struct {
	yield func(*ast.Reference) bool
	stop  bool
}

// ReferenceSeq returns an iterator of all references mentioned in the given
// zettel. This also includes references to images.
func ReferenceSeq(zn *ast.ZettelNode) iter.Seq[*ast.Reference] {
	return func(yield func(*ast.Reference) bool) {
		yielder := refYielder{yield, false}
		ast.Walk(&yielder, &zn.BlocksAST)
	}
}

// Visit all node to collect data for the summary.
func (y *refYielder) Visit(node ast.Node) ast.Visitor {
	if y.stop {
		return nil
	}
	var stop bool
	switch n := node.(type) {
	case *ast.TranscludeNode:

		stop = !y.yield(n.Ref)
	case *ast.LinkNode:


		stop = !y.yield(n.Ref)
	case *ast.EmbedRefNode:


		stop = !y.yield(n.Ref)
	}
	if stop {
		y.stop = true
		return nil
	}

	return y
}

// Package collect_test provides some unit test for collectors.
package collect_test

import (
	"slices"
	"testing"




	"zettelstore.de/z/internal/ast"
	"zettelstore.de/z/internal/collect"
)

func parseRef(s string) *ast.Reference {
	r := ast.ParseReference(s)

	if !r.IsValid() {
		panic(s)
	}
	return r
}

func TestReferenceSeq(t *testing.T) {
	t.Parallel()
	zn := &ast.ZettelNode{}
	summary := slices.Collect(collect.ReferenceSeq(zn))
	if len(summary) != 0 {
		t.Error("No references expected, but got:", summary)
	}

	intNode := &ast.LinkNode{Ref: parseRef("01234567890123")}
	para := ast.CreateParaNode(intNode, &ast.LinkNode{Ref: parseRef("https://zettelstore.de/z")})
	zn.BlocksAST = ast.BlockSlice{para}
	summary = slices.Collect(collect.ReferenceSeq(zn))
	if len(summary) != 2 {
		t.Error("2 refs expected, but got:", summary)
	}

	para.Inlines = append(para.Inlines, intNode)
	summary = slices.Collect(collect.ReferenceSeq(zn))
	if cnt := len(summary); cnt != 3 {
		t.Error("Ref count does not work. Expected: 3, got", summary)
	}

	zn = &ast.ZettelNode{
		BlocksAST: ast.BlockSlice{ast.CreateParaNode(&ast.EmbedRefNode{Ref: parseRef("12345678901234")})},
	}
	summary = slices.Collect(collect.ReferenceSeq(zn))
	if len(summary) != 1 {
		t.Error("Only one image ref expected, but got: ", summary)
	}
}

// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

// Package collect provides functions to collect items from a syntax tree.
package collect

import "zettelstore.de/z/internal/ast"



// Order of internal links within the given zettel.

func Order(zn *ast.ZettelNode) (result []*ast.LinkNode) {


	for _, bn := range zn.BlocksAST {
		ln, ok := bn.(*ast.NestedListNode)
		if !ok {
			continue
		}
		switch ln.Kind {
		case ast.NestedListOrdered, ast.NestedListUnordered:

			for _, is := range ln.Items {
				if ln := firstItemZettelLink(is); ln != nil {
					result = append(result, ln)
				}
			}
		}
	}

	return result
}

func firstItemZettelLink(is ast.ItemSlice) *ast.LinkNode {

	for _, in := range is {
		if pn, ok := in.(*ast.ParaNode); ok {


			if ln := firstInlineZettelLink(pn.Inlines); ln != nil {
				return ln
			}
		}
	}
	return nil
}

func firstInlineZettelLink(is ast.InlineSlice) (result *ast.LinkNode) {
	for _, inl := range is {


		switch in := inl.(type) {
		case *ast.LinkNode:
			return in
		case *ast.EmbedRefNode:




			result = firstInlineZettelLink(in.Inlines)
		case *ast.EmbedBLOBNode:

			result = firstInlineZettelLink(in.Inlines)
		case *ast.CiteNode:

			result = firstInlineZettelLink(in.Inlines)
		case *ast.FootnoteNode:
			// Ignore references in footnotes
			continue
		case *ast.FormatNode:

			result = firstInlineZettelLink(in.Inlines)
		default:
			continue
		}
		if result != nil {
			return result

		}
	}
	return nil
}

// Package encoder provides a generic interface to encode the abstract syntax
// tree into some text form.
package encoder

import (
	"io"


	"t73f.de/r/zsc/api"
	"t73f.de/r/zsc/domain/meta"
	"t73f.de/r/zsc/shtml"

	"zettelstore.de/z/internal/ast"
)

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

	// WriteMeta encodes just the metadata.
	WriteMeta(io.Writer, *meta.Meta) (int, error)

	// WiteBlocks encodes a block slice, i.e. the zettel content.
	WriteBlocks(io.Writer, *ast.BlockSlice) (int, error)
}

// Create builds a new encoder with the given options.
func Create(enc api.EncodingEnum, params *CreateParameter) Encoder {
	switch enc {
	case api.EncoderHTML:
		// We need a new transformer every time, because tx.inVerse must be unique.
		// If we can refactor it out, the transformer can be created only once.
		return &htmlEncoder{
			tx:   NewSzTransformer(),
			th:   shtml.NewEvaluator(1),
			lang: params.Lang,
		}
	case api.EncoderMD:
		return &mdEncoder{lang: params.Lang}
	case api.EncoderSHTML:
		// We need a new transformer every time, because tx.inVerse must be unique.
		// If we can refactor it out, the transformer can be created only once.
		return &shtmlEncoder{
			tx:   NewSzTransformer(),
			th:   shtml.NewEvaluator(1),
			lang: params.Lang,
		}
	case api.EncoderSz:
		// We need a new transformer every time, because trans.inVerse must be unique.
		// If we can refactor it out, the transformer can be created only once.
		return &szEncoder{trans: NewSzTransformer()}
	case api.EncoderText:
		return (*TextEncoder)(nil)
	case api.EncoderZmk:
		return (*zmkEncoder)(nil)
	}
	return nil
}

import (
	"testing"

	"t73f.de/r/zsc/domain/id"
	"t73f.de/r/zsc/domain/meta"
	"t73f.de/r/zsx/input"

	"zettelstore.de/z/internal/config"
	"zettelstore.de/z/internal/parser"
)

type blobTestCase struct {
	descr  string
	syntax string
	blob   []byte

			0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x08, 0x00, 0x00, 0x00, 0x00, 0x3a, 0x7e, 0x9b,
			0x55, 0x00, 0x00, 0x00, 0x0a, 0x49, 0x44, 0x41, 0x54, 0x78, 0x9c, 0x63, 0x62, 0x00, 0x00, 0x00,
			0x06, 0x00, 0x03, 0x36, 0x37, 0x7c, 0xa8, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4e, 0x44, 0xae,
			0x42, 0x60, 0x82,
		},
		expect: expectMap{
			encoderHTML:  `<p><img alt="Minimal PNG" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABgADNjd8qAAAAABJRU5ErkJggg=="></p>`,
			encoderSz:    `(BLOCK (BLOB () ((TEXT "Minimal PNG")) "png" "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABgADNjd8qAAAAABJRU5ErkJggg=="))`,
			encoderSHTML: `((p (img (@ (alt . "Minimal PNG") (src . "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABgADNjd8qAAAAABJRU5ErkJggg==")))))`,
			encoderText:  "",
			encoderZmk:   `%% Unable to display BLOB with description 'Minimal PNG' and syntax 'png'.`,
		},
	},
}

func TestBlob(t *testing.T) {
	m := meta.New(id.Invalid)
	for testNum, tc := range pngTestCases {
		m.Set(meta.KeyTitle, meta.Value(tc.descr))
		inp := input.NewInput(tc.blob)
		bs := parser.Parse(inp, m, tc.syntax, config.NoHTML)
		checkEncodings(t, testNum, bs, false, tc.descr, tc.expect, "???")
	}
}

// under this license.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2021-present Detlef Stern
//-----------------------------------------------------------------------------

package encoder_test







var tcsBlock = []zmkTestCase{
	{
		descr: "Empty Zettelmarkup should produce near nothing",
		zmk:   "",
		expect: expectMap{
			encoderHTML:  "",

	{
		descr: "Simple Heading",
		zmk:   `=== Top Job`,
		expect: expectMap{
			encoderHTML:  "<h2 id=\"top-job\">Top Job</h2>",
			encoderMD:    "# Top Job",
			encoderSz:    `(BLOCK (HEADING 1 () "top-job" "top-job" (TEXT "Top Job")))`,
			encoderSHTML: `((h2 (@ (id . "top-job")) "Top Job"))`,
			encoderText:  `Top Job`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple List",
		zmk:   "* A\n* B\n* C",
		expect: expectMap{
			encoderHTML:  "<ul><li>A</li><li>B</li><li>C</li></ul>",
			encoderMD:    "* A\n* B\n* C",
			encoderSz:    `(BLOCK (UNORDERED () (INLINE (TEXT "A")) (INLINE (TEXT "B")) (INLINE (TEXT "C"))))`,
			encoderSHTML: `((ul (li "A") (li "B") (li "C")))`,
			encoderText:  "A\nB\nC",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Nested List",
		zmk:   "* T1\n*# T2\n* T3\n** T4\n** T5\n* T6",
		expect: expectMap{
			encoderHTML:  `<ul><li><p>T1</p><ol><li>T2</li></ol></li><li><p>T3</p><ul><li>T4</li><li>T5</li></ul></li><li><p>T6</p></li></ul>`,
			encoderMD:    "* T1\n    1. T2\n* T3\n    * T4\n    * T5\n* T6",
			encoderSz:    `(BLOCK (UNORDERED () (BLOCK (PARA (TEXT "T1")) (ORDERED () (INLINE (TEXT "T2")))) (BLOCK (PARA (TEXT "T3")) (UNORDERED () (INLINE (TEXT "T4")) (INLINE (TEXT "T5")))) (BLOCK (PARA (TEXT "T6")))))`,
			encoderSHTML: `((ul (li (p "T1") (ol (li "T2"))) (li (p "T3") (ul (li "T4") (li "T5"))) (li (p "T6"))))`,
			encoderText:  "T1\nT2\nT3\nT4\nT5\nT6",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Sequence of two lists",
		zmk:   "* Item1.1\n* Item1.2\n* Item1.3\n\n* Item2.1\n* Item2.2",
		expect: expectMap{
			encoderHTML:  "<ul><li>Item1.1</li><li>Item1.2</li><li>Item1.3</li><li>Item2.1</li><li>Item2.2</li></ul>",
			encoderMD:    "* Item1.1\n* Item1.2\n* Item1.3\n* Item2.1\n* Item2.2",
			encoderSz:    `(BLOCK (UNORDERED () (INLINE (TEXT "Item1.1")) (INLINE (TEXT "Item1.2")) (INLINE (TEXT "Item1.3")) (INLINE (TEXT "Item2.1")) (INLINE (TEXT "Item2.2"))))`,
			encoderSHTML: `((ul (li "Item1.1") (li "Item1.2") (li "Item1.3") (li "Item2.1") (li "Item2.2")))`,
			encoderText:  "Item1.1\nItem1.2\nItem1.3\nItem2.1\nItem2.2",
			encoderZmk:   "* Item1.1\n* Item1.2\n* Item1.3\n* Item2.1\n* Item2.2",
		},
	},
	{
		descr: "Simple horizontal rule",

	{
		descr: "Thematic break with attribute",
		zmk:   `---{lang="zmk"}`,
		expect: expectMap{
			encoderHTML:  `<hr lang="zmk">`,
			encoderMD:    "---",
			encoderSz:    `(BLOCK (THEMATIC (("lang" . "zmk"))))`,
			encoderSHTML: `((hr (@ (lang . "zmk"))))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "No list after paragraph",
		zmk:   "Text\n*abc",

	},
	{
		descr: "A list after paragraph",
		zmk:   "Text\n# abc",
		expect: expectMap{
			encoderHTML:  "<p>Text</p><ol><li>abc</li></ol>",
			encoderMD:    "Text\n\n1. abc",
			encoderSz:    `(BLOCK (PARA (TEXT "Text")) (ORDERED () (INLINE (TEXT "abc"))))`,
			encoderSHTML: `((p "Text") (ol (li "abc")))`,
			encoderText:  "Text\nabc",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple List Quote",
		zmk:   "> ToBeOrNotToBe",
		expect: expectMap{
			encoderHTML:  "<blockquote>ToBeOrNotToBe</blockquote>",
			encoderMD:    "> ToBeOrNotToBe",
			encoderSz:    `(BLOCK (QUOTATION () (INLINE (TEXT "ToBeOrNotToBe"))))`,
			encoderSHTML: `((blockquote (@L "ToBeOrNotToBe")))`,
			encoderText:  "ToBeOrNotToBe",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Quote Block",

	{
		descr: "Simple Verbatim Eval",
		zmk:   "~~~\nHello\nWorld\n~~~",
		expect: expectMap{
			encoderHTML:  "<pre><code class=\"zs-eval\">Hello\nWorld</code></pre>",
			encoderMD:    "",
			encoderSz:    `(BLOCK (VERBATIM-EVAL () "Hello\nWorld"))`,
			encoderSHTML: "((pre (code (@ (class . \"zs-eval\")) \"Hello\\nWorld\")))",
			encoderText:  "Hello\nWorld",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Verbatim Math",
		zmk:   "$$$\nHello\n\\LaTeX\n$$$",
		expect: expectMap{
			encoderHTML:  "<pre><code class=\"zs-math\">Hello\n\\LaTeX</code></pre>",
			encoderMD:    "",
			encoderSz:    `(BLOCK (VERBATIM-MATH () "Hello\n\\LaTeX"))`,
			encoderSHTML: "((pre (code (@ (class . \"zs-math\")) \"Hello\\n\\\\LaTeX\")))",
			encoderText:  "Hello\n\\LaTeX",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Description List",
		zmk:   "; Zettel\n: Paper\n: Note\n; Zettelkasten\n: Slip box",

	},
	{
		descr: "Simple Table",
		zmk:   "|c1|c2|c3\n|d1||d3",
		expect: expectMap{
			encoderHTML:  `<table><tbody><tr><td>c1</td><td>c2</td><td>c3</td></tr><tr><td>d1</td><td></td><td>d3</td></tr></tbody></table>`,
			encoderMD:    "",
			encoderSz:    `(BLOCK (TABLE () ((CELL () (TEXT "c1")) (CELL () (TEXT "c2")) (CELL () (TEXT "c3"))) ((CELL () (TEXT "d1")) (CELL ()) (CELL () (TEXT "d3")))))`,
			encoderSHTML: `((table (tbody (tr (td "c1") (td "c2") (td "c3")) (tr (td "d1") (td) (td "d3")))))`,
			encoderText:  "c1 c2 c3\nd1  d3",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Table with alignment and comment",
		zmk: `|h1>|=h2|h3:|
|%--+---+---+
|<c1|c2|:c3|
|f1|f2|=f3`,
		expect: expectMap{
			encoderHTML:  `<table><thead><tr><th class="right">h1</th><th>h2</th><th class="center">h3</th></tr></thead><tbody><tr><td class="left">c1</td><td>c2</td><td class="center">c3</td></tr><tr><td class="right">f1</td><td>f2</td><td class="center">=f3</td></tr></tbody></table>`,
			encoderMD:    "",
			encoderSz:    `(BLOCK (TABLE ((CELL ((align . "right")) (TEXT "h1")) (CELL () (TEXT "h2")) (CELL ((align . "center")) (TEXT "h3"))) ((CELL ((align . "left")) (TEXT "c1")) (CELL () (TEXT "c2")) (CELL ((align . "center")) (TEXT "c3"))) ((CELL ((align . "right")) (TEXT "f1")) (CELL () (TEXT "f2")) (CELL ((align . "center")) (TEXT "=f3")))))`,
			encoderSHTML: `((table (thead (tr (th (@ (class . "right")) "h1") (th "h2") (th (@ (class . "center")) "h3"))) (tbody (tr (td (@ (class . "left")) "c1") (td "c2") (td (@ (class . "center")) "c3")) (tr (td (@ (class . "right")) "f1") (td "f2") (td (@ (class . "center")) "=f3")))))`,
			encoderText:  "h1 h2 h3\nc1 c2 c3\nf1 f2 =f3",
			encoderZmk: /*`|=h1>|=h2|=h3:
			|<c1|c2|c3
			|f1|f2|=f3`,*/
			`|=>h1|=h2|=:h3
|<c1|c2|:c3
|>f1|f2|:=f3`,
		},
	},
	{
		descr: "Simple Endnote",
		zmk:   `Text[^Endnote]`,
		expect: expectMap{
			encoderHTML:  "<p>Text<sup id=\"fnref:1\"><a class=\"zs-noteref\" href=\"#fn:1\" role=\"doc-noteref\">1</a></sup></p><ol class=\"zs-endnotes\"><li class=\"zs-endnote\" id=\"fn:1\" role=\"doc-endnote\" value=\"1\">Endnote <a class=\"zs-endnote-backref\" href=\"#fnref:1\" role=\"doc-backlink\">\u21a9\ufe0e</a></li></ol>",
			encoderMD:    "Text",
			encoderSz:    `(BLOCK (PARA (TEXT "Text") (ENDNOTE () (TEXT "Endnote"))))`,
			encoderSHTML: "((p \"Text\" (sup (@ (id . \"fnref:1\")) (a (@ (class . \"zs-noteref\") (href . \"#fn:1\") (role . \"doc-noteref\")) \"1\"))))",
			encoderText:  "Text Endnote",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Nested Endnotes",
		zmk:   `Text[^Endnote[^Nested]]`,
		expect: expectMap{
			encoderHTML:  "<p>Text<sup id=\"fnref:1\"><a class=\"zs-noteref\" href=\"#fn:1\" role=\"doc-noteref\">1</a></sup></p><ol class=\"zs-endnotes\"><li class=\"zs-endnote\" id=\"fn:1\" role=\"doc-endnote\" value=\"1\">Endnote<sup id=\"fnref:2\"><a class=\"zs-noteref\" href=\"#fn:2\" role=\"doc-noteref\">2</a></sup> <a class=\"zs-endnote-backref\" href=\"#fnref:1\" role=\"doc-backlink\">\u21a9\ufe0e</a></li><li class=\"zs-endnote\" id=\"fn:2\" role=\"doc-endnote\" value=\"2\">Nested <a class=\"zs-endnote-backref\" href=\"#fnref:2\" role=\"doc-backlink\">\u21a9\ufe0e</a></li></ol>",
			encoderMD:    "Text",
			encoderSz:    `(BLOCK (PARA (TEXT "Text") (ENDNOTE () (TEXT "Endnote") (ENDNOTE () (TEXT "Nested")))))`,
			encoderSHTML: "((p \"Text\" (sup (@ (id . \"fnref:1\")) (a (@ (class . \"zs-noteref\") (href . \"#fn:1\") (role . \"doc-noteref\")) \"1\"))))",
			encoderText:  "Text Endnote Nested",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Transclusion",
		zmk:   `{{{http://example.com/image}}}{width="100px"}`,
		expect: expectMap{
			encoderHTML:  `<p><img class="external" src="http://example.com/image" width="100px"></p>`,
			encoderMD:    "",
			encoderSz:    `(BLOCK (TRANSCLUDE (("width" . "100px")) (EXTERNAL "http://example.com/image")))`,
			encoderSHTML: `((p (img (@ (class . "external") (src . "http://example.com/image") (width . "100px")))))`,
			encoderText:  "",
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "A paragraph with a inline comment only should be empty in HTML",
		zmk:   `%% Comment`,
		expect: expectMap{
			// encoderHTML:  ``,
			encoderSz: `(BLOCK (PARA (LITERAL-COMMENT () "Comment")))`,
			// encoderSHTML: ``,
			encoderText: "",
			encoderZmk:  useZmk,
		},
	},

























	{
		descr: "",
		zmk:   ``,
		expect: expectMap{
			encoderHTML:  ``,
			encoderSz:    `(BLOCK)`,
			encoderSHTML: `()`,
			encoderText:  "",
			encoderZmk:   useZmk,
		},
	},
}

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

	{
		descr: "Quotes formatting (german)",
		zmk:   `""quotes""{lang=de}`,
		expect: expectMap{
			encoderHTML:  `<p><span lang="de">&bdquo;quotes&ldquo;</span></p>`,
			encoderMD:    "&bdquo;quotes&ldquo;",
			encoderSz:    `(BLOCK (PARA (FORMAT-QUOTE (("lang" . "de")) (TEXT "quotes"))))`,
			encoderSHTML: `((p (span (@ (lang . "de")) (@H "&bdquo;") "quotes" (@H "&ldquo;"))))`,
			encoderText:  `quotes`,
			encoderZmk:   `""quotes""{lang="de"}`,
		},
	},
	{
		descr: "Empty quotes (default)",
		zmk:   `""""`,

	{
		descr: "Empty quotes (unknown)",
		zmk:   `""""{lang=unknown}`,
		expect: expectMap{
			encoderHTML:  `<p><span lang="unknown">&quot;&quot;</span></p>`,
			encoderMD:    "&quot;&quot;",
			encoderSz:    `(BLOCK (PARA (FORMAT-QUOTE (("lang" . "unknown")))))`,
			encoderSHTML: `((p (span (@ (lang . "unknown")) (@H "&quot;" "&quot;"))))`,
			encoderText:  ``,
			encoderZmk:   `""""{lang="unknown"}`,
		},
	},
	{
		descr: "Nested quotes (default)",
		zmk:   `""say: ::""yes, ::""or?""::""::""`,

	{
		descr: "Math formatting",
		zmk:   `$$\TeX$$`,
		expect: expectMap{
			encoderHTML:  `<p><code class="zs-math">\TeX</code></p>`,
			encoderMD:    "\\TeX",
			encoderSz:    `(BLOCK (PARA (LITERAL-MATH () "\\TeX")))`,
			encoderSHTML: `((p (code (@ (class . "zs-math")) "\\TeX")))`,
			encoderText:  `\TeX`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Nested Span Quote formatting",
		zmk:   `::""abc""::{lang=fr}`,
		expect: expectMap{
			encoderHTML:  `<p><span lang="fr">&laquo;&nbsp;abc&nbsp;&raquo;</span></p>`,
			encoderMD:    "&laquo;&nbsp;abc&nbsp;&raquo;",
			encoderSz:    `(BLOCK (PARA (FORMAT-SPAN (("lang" . "fr")) (FORMAT-QUOTE () (TEXT "abc")))))`,
			encoderSHTML: `((p (span (@ (lang . "fr")) (@L (@H "&laquo;" "&nbsp;") "abc" (@H "&nbsp;" "&raquo;")))))`,
			encoderText:  `abc`,
			encoderZmk:   `::""abc""::{lang="fr"}`,
		},
	},












	{
		descr: "Simple Citation",
		zmk:   `[@Stern18]`,
		expect: expectMap{
			encoderHTML:  `<p><span>Stern18</span></p>`, // TODO
			encoderMD:    "",
			encoderSz:    `(BLOCK (PARA (CITE () "Stern18")))`,

			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Comment after text and with -->",
		zmk:   `Text%%{-} comment --> end`,
		expect: expectMap{
			encoderHTML:  `<p>Text<!-- comment -&#45;> end --></p>`,
			encoderMD:    "Text",
			encoderSz:    `(BLOCK (PARA (TEXT "Text") (LITERAL-COMMENT (("-" . "")) "comment --> end")))`,
			encoderSHTML: `((p "Text" (@@ "comment --> end")))`,
			encoderText:  `Text`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple inline endnote",
		zmk:   `[^endnote]`,
		expect: expectMap{
			encoderHTML:  `<p><sup id="fnref:1"><a class="zs-noteref" href="#fn:1" role="doc-noteref">1</a></sup></p><ol class="zs-endnotes"><li class="zs-endnote" id="fn:1" role="doc-endnote" value="1">endnote <a class="zs-endnote-backref" href="#fnref:1" role="doc-backlink">↩︎</a></li></ol>`,
			encoderMD:    "",
			encoderSz:    `(BLOCK (PARA (ENDNOTE () (TEXT "endnote"))))`,
			encoderSHTML: `((p (sup (@ (id . "fnref:1")) (a (@ (class . "zs-noteref") (href . "#fn:1") (role . "doc-noteref")) "1"))))`,
			encoderText:  `endnote`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple mark",
		zmk:   `[!mark]`,
		expect: expectMap{
			encoderHTML:  `<p><a id="mark"></a></p>`,
			encoderMD:    "",
			encoderSz:    `(BLOCK (PARA (MARK "mark" "mark" "mark")))`,
			encoderSHTML: `((p (a (@ (id . "mark")))))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Mark with text",
		zmk:   `[!mark|with text]`,
		expect: expectMap{
			encoderHTML:  `<p><a id="mark">with text</a></p>`,
			encoderMD:    "with text",
			encoderSz:    `(BLOCK (PARA (MARK "mark" "mark" "mark" (TEXT "with text"))))`,
			encoderSHTML: `((p (a (@ (id . "mark")) "with text")))`,
			encoderText:  `with text`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Invalid Link",
		zmk:   `[[link|00000000000000]]`,

	{
		descr: "Dummy Link",
		zmk:   `[[abc]]`,
		expect: expectMap{
			encoderHTML:  `<p><a href="abc">abc</a></p>`,
			encoderMD:    "[abc](abc)",
			encoderSz:    `(BLOCK (PARA (LINK () (HOSTED "abc"))))`,
			encoderSHTML: `((p (a (@ (href . "abc")) "abc")))`,












			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple URL",
		zmk:   `[[https://zettelstore.de]]`,
		expect: expectMap{
			encoderHTML:  `<p><a href="https://zettelstore.de" rel="external">https://zettelstore.de</a></p>`,
			encoderMD:    "<https://zettelstore.de>",
			encoderSz:    `(BLOCK (PARA (LINK () (EXTERNAL "https://zettelstore.de"))))`,
			encoderSHTML: `((p (a (@ (href . "https://zettelstore.de") (rel . "external")) "https://zettelstore.de")))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "URL with Text",
		zmk:   `[[Home|https://zettelstore.de]]`,
		expect: expectMap{
			encoderHTML:  `<p><a href="https://zettelstore.de" rel="external">Home</a></p>`,
			encoderMD:    "[Home](https://zettelstore.de)",
			encoderSz:    `(BLOCK (PARA (LINK () (EXTERNAL "https://zettelstore.de") (TEXT "Home"))))`,
			encoderSHTML: `((p (a (@ (href . "https://zettelstore.de") (rel . "external")) "Home")))`,
			encoderText:  `Home`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Zettel ID",
		zmk:   `[[00000000000100]]`,
		expect: expectMap{
			encoderHTML:  `<p><a href="00000000000100">00000000000100</a></p>`,
			encoderMD:    "[00000000000100](00000000000100)",
			encoderSz:    `(BLOCK (PARA (LINK () (ZETTEL "00000000000100"))))`,
			encoderSHTML: `((p (a (@ (href . "00000000000100")) "00000000000100")))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Zettel ID with Text",
		zmk:   `[[Config|00000000000100]]`,
		expect: expectMap{
			encoderHTML:  `<p><a href="00000000000100">Config</a></p>`,
			encoderMD:    "[Config](00000000000100)",
			encoderSz:    `(BLOCK (PARA (LINK () (ZETTEL "00000000000100") (TEXT "Config"))))`,
			encoderSHTML: `((p (a (@ (href . "00000000000100")) "Config")))`,
			encoderText:  `Config`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Simple Zettel ID with fragment",
		zmk:   `[[00000000000100#frag]]`,
		expect: expectMap{
			encoderHTML:  `<p><a href="00000000000100#frag">00000000000100#frag</a></p>`,
			encoderMD:    "[00000000000100#frag](00000000000100#frag)",
			encoderSz:    `(BLOCK (PARA (LINK () (ZETTEL "00000000000100#frag"))))`,
			encoderSHTML: `((p (a (@ (href . "00000000000100#frag")) "00000000000100#frag")))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Zettel ID with Text and fragment",
		zmk:   `[[Config|00000000000100#frag]]`,
		expect: expectMap{
			encoderHTML:  `<p><a href="00000000000100#frag">Config</a></p>`,
			encoderMD:    "[Config](00000000000100#frag)",
			encoderSz:    `(BLOCK (PARA (LINK () (ZETTEL "00000000000100#frag") (TEXT "Config"))))`,
			encoderSHTML: `((p (a (@ (href . "00000000000100#frag")) "Config")))`,
			encoderText:  `Config`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Fragment link to self",
		zmk:   `[[#frag]]`,
		expect: expectMap{
			encoderHTML:  `<p><a href="#frag">#frag</a></p>`,
			encoderMD:    "[#frag](#frag)",
			encoderSz:    `(BLOCK (PARA (LINK () (SELF "#frag"))))`,
			encoderSHTML: `((p (a (@ (href . "#frag")) "#frag")))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Hosted link",
		zmk:   `[[H|/hosted]]`,
		expect: expectMap{
			encoderHTML:  `<p><a href="/hosted">H</a></p>`,
			encoderMD:    "[H](/hosted)",
			encoderSz:    `(BLOCK (PARA (LINK () (HOSTED "/hosted") (TEXT "H"))))`,
			encoderSHTML: `((p (a (@ (href . "/hosted")) "H")))`,
			encoderText:  `H`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Based link",
		zmk:   `[[B|//based]]`,
		expect: expectMap{
			encoderHTML:  `<p><a href="/based">B</a></p>`,
			encoderMD:    "[B](/based)",
			encoderSz:    `(BLOCK (PARA (LINK () (BASED "/based") (TEXT "B"))))`,
			encoderText:  `B`,
			encoderSHTML: `((p (a (@ (href . "/based")) "B")))`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Relative link",
		zmk:   `[[R|../relative]]`,
		expect: expectMap{
			encoderHTML:  `<p><a href="../relative">R</a></p>`,
			encoderMD:    "[R](../relative)",
			encoderSz:    `(BLOCK (PARA (LINK () (HOSTED "../relative") (TEXT "R"))))`,
			encoderSHTML: `((p (a (@ (href . "../relative")) "R")))`,
			encoderText:  `R`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Query link w/o text",
		zmk:   `[[query:title:syntax]]`,
		expect: expectMap{
			encoderHTML:  `<p><a href="?q=title%3Asyntax">title:syntax</a></p>`,
			encoderMD:    "",
			encoderSz:    `(BLOCK (PARA (LINK () (QUERY "title:syntax"))))`,
			encoderSHTML: `((p (a (@ (href . "?q=title%3Asyntax")) "title:syntax")))`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Query link with text",
		zmk:   `[[Q|query:title:syntax]]`,
		expect: expectMap{
			encoderHTML:  `<p><a href="?q=title%3Asyntax">Q</a></p>`,
			encoderMD:    "Q",
			encoderSz:    `(BLOCK (PARA (LINK () (QUERY "title:syntax") (TEXT "Q"))))`,
			encoderSHTML: `((p (a (@ (href . "?q=title%3Asyntax")) "Q")))`,
			encoderText:  `Q`,
			encoderZmk:   useZmk,
		},
	},
	{
		descr: "Dummy Embed",
		zmk:   `{{abc}}`,
		expect: expectMap{
			encoderHTML:  `<p><img src="abc"></p>`,
			encoderMD:    "![abc](abc)",
			encoderSz:    `(BLOCK (PARA (EMBED () (HOSTED "abc") "")))`,
			encoderSHTML: `((p (img (@ (src . "abc")))))`,












			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},












	{
		descr: "",
		zmk:   ``,
		expect: expectMap{
			encoderHTML:  ``,
			encoderMD:    "",
			encoderSz:    `(BLOCK)`,
			encoderSHTML: `()`,
			encoderText:  ``,
			encoderZmk:   useZmk,
		},
	},
}

package encoder_test

import (
	"fmt"
	"strings"
	"testing"

	"t73f.de/r/sx/sxreader"
	"t73f.de/r/zsc/api"
	"t73f.de/r/zsc/domain/meta"
	"t73f.de/r/zsx/input"

	"zettelstore.de/z/internal/ast"
	"zettelstore.de/z/internal/config"
	"zettelstore.de/z/internal/encoder"
	"zettelstore.de/z/internal/parser"
)

type zmkTestCase struct {
	descr  string
	zmk    string


	inline bool
	expect expectMap
}

type expectMap map[api.EncodingEnum]string

const useZmk = "\000"
const (
	encoderHTML  = api.EncoderHTML
	encoderMD    = api.EncoderMD
	encoderSz    = api.EncoderSz
	encoderSHTML = api.EncoderSHTML
	encoderText  = api.EncoderText
	encoderZmk   = api.EncoderZmk
)

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

func executeTestCases(t *testing.T, testCases []zmkTestCase) {
	for testNum, tc := range testCases {
		inp := input.NewInput([]byte(tc.zmk))








		bs := parser.Parse(inp, nil, meta.ValueSyntaxZmk, config.NoHTML)

		checkEncodings(t, testNum, bs, tc.inline, tc.descr, tc.expect, tc.zmk)
		checkSz(t, testNum, bs, tc.inline, tc.descr)
	}
}

func checkEncodings(t *testing.T, testNum int, bs ast.BlockSlice, isInline bool, descr string, expected expectMap, zmkDefault string) {
	for enc, exp := range expected {
		encdr := encoder.Create(enc, &encoder.CreateParameter{Lang: meta.ValueLangEN})
		got, err := encode(encdr, bs)
		if err != nil {
			prefix := fmt.Sprintf("Test #%d", testNum)
			if d := descr; d != "" {
				prefix += "\nReason:   " + d
			}
			prefix += "\nMode:     " + mode(isInline)
			t.Errorf("%s\nEncoder:  %s\nError:    %v", prefix, enc, err)

			}
			prefix += "\nMode:     " + mode(isInline)
			t.Errorf("%s\nEncoder:  %s\nExpected: %q\nGot:      %q", prefix, enc, exp, got)
		}
	}
}

func checkSz(t *testing.T, testNum int, bs ast.BlockSlice, isInline bool, descr string) {
	t.Helper()
	encdr := encoder.Create(encoderSz, nil)
	exp, err := encode(encdr, bs)
	if err != nil {
		t.Error(err)
		return
	}
	val, err := sxreader.MakeReader(strings.NewReader(exp)).Read()
	if err != nil {
		t.Error(err)
		return
	}
	got := val.String()
	if exp != got {
		prefix := fmt.Sprintf("Test #%d", testNum)
		if d := descr; d != "" {
			prefix += "\nReason:   " + d
		}
		prefix += "\nMode:     " + mode(isInline)
		t.Errorf("%s\n\nExpected: %q\nGot:      %q", prefix, exp, got)
	}
}

func encode(e encoder.Encoder, bs ast.BlockSlice) (string, error) {
	var sb strings.Builder
	_, err := e.WriteBlocks(&sb, &bs)
	return sb.String(), err
}

func mode(isInline bool) string {
	if isInline {
		return "inline"
	}
	return "block"
}

	"io"
	"strings"

	"t73f.de/r/sx"
	"t73f.de/r/sxwebs/sxhtml"
	"t73f.de/r/zsc/domain/meta"
	"t73f.de/r/zsc/shtml"



	"zettelstore.de/z/internal/ast"
)

// htmlEncoder contains all data needed for encoding.
type htmlEncoder struct {
	tx      SzTransformer
	th      *shtml.Evaluator
	lang    string
	textEnc TextEncoder
}

// WriteZettel encodes a full zettel as HTML5.
func (he *htmlEncoder) WriteZettel(w io.Writer, zn *ast.ZettelNode) (int, error) {
	env := shtml.MakeEnvironment(he.lang)
	hm, err := he.th.Evaluate(he.tx.GetMeta(zn.InhMeta), &env)
	if err != nil {
		return 0, err
	}

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

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

	var head sx.ListBuilder
	head.AddN(
		shtml.SymHead,
		sx.Nil().Cons(sx.Nil().Cons(sx.Cons(sx.MakeSymbol("charset"), sx.MakeString("utf-8"))).Cons(sxhtml.SymAttr)).Cons(shtml.SymMeta),
	)
	head.ExtendBang(hm)
	var sb strings.Builder
	if hasTitle {
		_, _ = he.textEnc.WriteInlines(&sb, &isTitle)
	} else {
		sb.Write(zn.Meta.Zid.Bytes())
	}
	head.Add(sx.MakeList(shtml.SymAttrTitle, sx.MakeString(sb.String())))

	var body sx.ListBuilder
	body.Add(shtml.SymBody)

	)

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

// WriteMeta encodes meta data as HTML5.
func (he *htmlEncoder) WriteMeta(w io.Writer, m *meta.Meta) (int, error) {
	env := shtml.MakeEnvironment(he.lang)
	hm, err := he.th.Evaluate(he.tx.GetMeta(m), &env)
	if err != nil {
		return 0, err
	}
	gen := sxhtml.NewGenerator().SetNewline()
	return gen.WriteListHTML(w, hm)
}

// WriteBlocks encodes a block slice.
func (he *htmlEncoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {
	env := shtml.MakeEnvironment(he.lang)
	hobj, err := he.th.Evaluate(he.tx.GetSz(bs), &env)
	if err == nil {
		gen := sxhtml.NewGenerator()
		length, err2 := gen.WriteListHTML(w, hobj)
		if err2 != nil {
			return length, err2
		}

		l, err2 := gen.WriteHTML(w, shtml.Endnotes(&env))
		length += l
		return length, err2
	}
	return 0, err
}

package encoder

// Encodes the abstract syntax tree back into Markdown.

import (
	"io"



	"t73f.de/r/zsc/domain/meta"
	"t73f.de/r/zsc/shtml"

	"t73f.de/r/zsx"

	"zettelstore.de/z/internal/ast"
)

// mdEncoder contains all data needed for encoding.
type mdEncoder struct {
	lang string
}

// WriteZettel writes the encoded zettel to the writer.
func (me *mdEncoder) WriteZettel(w io.Writer, zn *ast.ZettelNode) (int, error) {
	v := newMDVisitor(w, me.lang)
	v.acceptMeta(zn.InhMeta)
	if zn.InhMeta.YamlSep {
		v.b.WriteString("---\n")
	} else {
		v.b.WriteLn()
	}
	ast.Walk(&v, &zn.BlocksAST)
	length, err := v.b.Flush()
	return length, err
}

// WriteMeta encodes meta data as markdown.
func (me *mdEncoder) WriteMeta(w io.Writer, m *meta.Meta) (int, error) {
	v := newMDVisitor(w, me.lang)
	v.acceptMeta(m)
	length, err := v.b.Flush()
	return length, err
}

func (v *mdVisitor) acceptMeta(m *meta.Meta) {
	for key, val := range m.Computed() {
		v.b.WriteStrings(key, ": ", string(val), "\n")
	}
}

// WriteBlocks writes the content of a block slice to the writer.
func (me *mdEncoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {
	v := newMDVisitor(w, me.lang)
	ast.Walk(&v, bs)
	length, err := v.b.Flush()
	return length, err
}

// mdVisitor writes the abstract syntax tree to an EncWriter.
type mdVisitor struct {
	b            encWriter
	listInfo     []int
	listPrefix   string
	langStack    shtml.LangStack
	quoteNesting uint
}

func newMDVisitor(w io.Writer, lang string) mdVisitor {
	return mdVisitor{b: newEncWriter(w), langStack: shtml.NewLangStack(lang)}
}


// pushAttribute adds the current attributes to the visitor.
func (v *mdVisitor) pushAttributes(a zsx.Attributes) {
	if value, ok := a.Get("lang"); ok {

		v.langStack.Push(value)
	} else {
		v.langStack.Dup()
	}
}


// popAttributes removes the current attributes from the visitor.
func (v *mdVisitor) popAttributes() { v.langStack.Pop() }





// getLanguage returns the current language,

func (v *mdVisitor) getLanguage() string { return v.langStack.Top() }


func (v *mdVisitor) getQuotes() (string, string, bool) {
	qi := shtml.GetQuoteInfo(v.getLanguage())
	leftQ, rightQ := qi.GetQuotes(v.quoteNesting)
	return leftQ, rightQ, qi.GetNBSp()
}


func (v *mdVisitor) Visit(node ast.Node) ast.Visitor {

	switch n := node.(type) {
	case *ast.BlockSlice:
		v.visitBlockSlice(n)
	case *ast.VerbatimNode:



		v.visitVerbatim(n)
	case *ast.RegionNode:
		v.visitRegion(n)
	case *ast.HeadingNode:



		v.visitHeading(n)
	case *ast.HRuleNode:


		v.b.WriteString("---")

	case *ast.NestedListNode:





		v.visitNestedList(n)




	case *ast.DescriptionListNode:


		return nil // Should write no content
	case *ast.TableNode:


		return nil // Should write no content
	case *ast.TextNode:






		v.b.WriteString(n.Text)
	case *ast.BreakNode:

		v.visitBreak(n)


	case *ast.LinkNode:

		v.visitLink(n)

	case *ast.EmbedRefNode:

		v.visitEmbedRef(n)
	case *ast.FootnoteNode:
		return nil // Should write no content
	case *ast.FormatNode:
		v.visitFormat(n)
	case *ast.LiteralNode:



		v.visitLiteral(n)


	default:
		return v
	}


	return nil
}



func (v *mdVisitor) visitBlockSlice(bs *ast.BlockSlice) {

	for i, bn := range *bs {
		if i > 0 {


			v.b.WriteString("\n\n")
		}
		ast.Walk(v, bn)
	}
}

func (v *mdVisitor) visitVerbatim(vn *ast.VerbatimNode) {
	lc := len(vn.Content)
	if vn.Kind != ast.VerbatimCode || lc == 0 {
		return
	}
	v.writeSpaces(4)
	lcm1 := lc - 1
	for i := 0; i < lc; i++ {
		b := vn.Content[i]
		if b != '\n' && b != '\r' {
			_ = v.b.WriteByte(b)
			continue
		}
		j := i + 1
		for ; j < lc; j++ {
			c := vn.Content[j]
			if c != '\n' && c != '\r' {
				break
			}
		}
		if j >= lcm1 {
			break
		}
		v.b.WriteLn()
		v.writeSpaces(4)
		i = j - 1
	}
}

func (v *mdVisitor) visitRegion(rn *ast.RegionNode) {
	if rn.Kind != ast.RegionQuote {
		return
	}
	v.pushAttributes(rn.Attrs)
	defer v.popAttributes()

	first := true
	for _, bn := range rn.Blocks {
		pn, ok := bn.(*ast.ParaNode)
		if !ok {
			continue
		}
		if !first {
			v.b.WriteString("\n>\n")
		}
		first = false
		v.b.WriteString("> ")
		ast.Walk(v, &pn.Inlines)
	}
}

func (v *mdVisitor) visitHeading(hn *ast.HeadingNode) {
	v.pushAttributes(hn.Attrs)
	defer v.popAttributes()

	const headingSigns = "###### "
	v.b.WriteString(headingSigns[len(headingSigns)-hn.Level-1:])
	ast.Walk(v, &hn.Inlines)
}

func (v *mdVisitor) visitNestedList(ln *ast.NestedListNode) {
	switch ln.Kind {
	case ast.NestedListOrdered:
		v.writeNestedList(ln, "1. ")
	case ast.NestedListUnordered:
		v.writeNestedList(ln, "* ")
	case ast.NestedListQuote:
		v.writeListQuote(ln)
	}
	v.listInfo = v.listInfo[:len(v.listInfo)-1]
}

func (v *mdVisitor) writeNestedList(ln *ast.NestedListNode, enum string) {
	v.listInfo = append(v.listInfo, len(enum))
	regIndent := 4*len(v.listInfo) - 4
	paraIndent := regIndent + len(enum)
	for i, item := range ln.Items {
		if i > 0 {
			v.b.WriteLn()
		}
		v.writeSpaces(regIndent)
		v.b.WriteString(enum)
		for j, in := range item {
			if j > 0 {
				v.b.WriteLn()
				if _, ok := in.(*ast.ParaNode); ok {
					v.writeSpaces(paraIndent)
				}
			}
			ast.Walk(v, in)
		}
	}
}

func (v *mdVisitor) writeListQuote(ln *ast.NestedListNode) {
	v.listInfo = append(v.listInfo, 0)
	if len(v.listInfo) > 1 {
		return
	}

	prefix := v.listPrefix
	v.listPrefix = "> "

	for i, item := range ln.Items {
		if i > 0 {
			v.b.WriteLn()
		}
		v.b.WriteString(v.listPrefix)
		for j, in := range item {
			if j > 0 {
				v.b.WriteLn()
				if _, ok := in.(*ast.ParaNode); ok {
					v.b.WriteString(v.listPrefix)
				}
			}
			ast.Walk(v, in)
		}
	}

	v.listPrefix = prefix
}

func (v *mdVisitor) visitBreak(bn *ast.BreakNode) {
	if bn.Hard {
		v.b.WriteString("\\\n")
	} else {
		v.b.WriteLn()
	}
	if l := len(v.listInfo); l > 0 {
		if v.listPrefix == "" {
			v.writeSpaces(4*l - 4 + v.listInfo[l-1])
		} else {
			v.writeSpaces(4*l - 4)
			v.b.WriteString(v.listPrefix)
		}
	}
}

func (v *mdVisitor) visitLink(ln *ast.LinkNode) {
	v.pushAttributes(ln.Attrs)
	defer v.popAttributes()

	v.writeReference(ln.Ref, ln.Inlines)
}

func (v *mdVisitor) visitEmbedRef(en *ast.EmbedRefNode) {
	v.pushAttributes(en.Attrs)
	defer v.popAttributes()

	_ = v.b.WriteByte('!')
	v.writeReference(en.Ref, en.Inlines)
}

func (v *mdVisitor) writeReference(ref *ast.Reference, is ast.InlineSlice) {
	if ref.State == ast.RefStateQuery {
		ast.Walk(v, &is)
	} else if len(is) > 0 {
		_ = v.b.WriteByte('[')
		ast.Walk(v, &is)
		v.b.WriteStrings("](", ref.String())
		_ = v.b.WriteByte(')')
	} else if isAutoLinkable(ref) {
		_ = v.b.WriteByte('<')
		v.b.WriteString(ref.String())
		_ = v.b.WriteByte('>')
	} else {
		s := ref.String()
		v.b.WriteStrings("[", s, "](", s, ")")
	}
}

func isAutoLinkable(ref *ast.Reference) bool {
	if ref.State != ast.RefStateExternal || ref.URL == nil {

		return false
	}

	return ref.URL.Scheme != ""
}

func (v *mdVisitor) visitFormat(fn *ast.FormatNode) {
	v.pushAttributes(fn.Attrs)
	defer v.popAttributes()

	switch fn.Kind {
	case ast.FormatEmph:
		_ = v.b.WriteByte('*')
		ast.Walk(v, &fn.Inlines)
		_ = v.b.WriteByte('*')
	case ast.FormatStrong:
		v.b.WriteString("__")
		ast.Walk(v, &fn.Inlines)
		v.b.WriteString("__")
	case ast.FormatQuote:
		v.writeQuote(fn)
	case ast.FormatMark:
		v.b.WriteString("<mark>")
		ast.Walk(v, &fn.Inlines)
		v.b.WriteString("</mark>")
	default:
		ast.Walk(v, &fn.Inlines)
	}
}

func (v *mdVisitor) writeQuote(fn *ast.FormatNode) {

	leftQ, rightQ, withNbsp := v.getQuotes()
	v.b.WriteString(leftQ)
	if withNbsp {
		v.b.WriteString("&nbsp;")
	}
	v.quoteNesting++
	ast.Walk(v, &fn.Inlines)
	v.quoteNesting--
	if withNbsp {
		v.b.WriteString("&nbsp;")
	}
	v.b.WriteString(rightQ)
}



































func (v *mdVisitor) visitLiteral(ln *ast.LiteralNode) {



	switch ln.Kind {



























	case ast.LiteralCode, ast.LiteralInput, ast.LiteralOutput:








		_ = v.b.WriteByte('`')




		_, _ = v.b.Write(ln.Content)







		_ = v.b.WriteByte('`')





	case ast.LiteralComment: // ignore everything



	default:









		_, _ = v.b.Write(ln.Content)


	}
}

func (v *mdVisitor) writeSpaces(n int) {
	for range n {
		v.b.WriteSpace()
	}
}

	"t73f.de/r/zsc/shtml"

	"zettelstore.de/z/internal/ast"
)

// shtmlEncoder contains all data needed for encoding.
type shtmlEncoder struct {
	tx   SzTransformer
	th   *shtml.Evaluator
	lang string
}

// WriteZettel writes the encoded zettel to the writer.
func (enc *shtmlEncoder) WriteZettel(w io.Writer, zn *ast.ZettelNode) (int, error) {
	env := shtml.MakeEnvironment(enc.lang)
	metaSHTML, err := enc.th.Evaluate(enc.tx.GetMeta(zn.InhMeta), &env)
	if err != nil {
		return 0, err
	}
	contentSHTML, err := enc.th.Evaluate(enc.tx.GetSz(&zn.BlocksAST), &env)
	if err != nil {
		return 0, err
	}
	result := sx.Cons(metaSHTML, contentSHTML)

	return result.Print(w)
}

// WriteMeta encodes meta data as s-expression.
func (enc *shtmlEncoder) WriteMeta(w io.Writer, m *meta.Meta) (int, error) {
	env := shtml.MakeEnvironment(enc.lang)
	metaSHTML, err := enc.th.Evaluate(enc.tx.GetMeta(m), &env)
	if err != nil {
		return 0, err
	}
	return sx.Print(w, metaSHTML)

}

// WriteBlocks writes a block slice to the writer
func (enc *shtmlEncoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {
	env := shtml.MakeEnvironment(enc.lang)
	hval, err := enc.th.Evaluate(enc.tx.GetSz(bs), &env)
	if err != nil {
		return 0, err
	}

	return sx.Print(w, hval)
}

	"t73f.de/r/sx"
	"t73f.de/r/zsc/domain/meta"

	"zettelstore.de/z/internal/ast"
)

// szEncoder contains all data needed for encoding.
type szEncoder struct {
	trans SzTransformer
}

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

}

// WriteMeta encodes meta data as s-expression.
func (enc *szEncoder) WriteMeta(w io.Writer, m *meta.Meta) (int, error) {

	return enc.trans.GetMeta(m).Print(w)
}

// WriteBlocks writes a block slice to the writer
func (enc *szEncoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {

	return enc.trans.GetSz(bs).Print(w)
}

//-----------------------------------------------------------------------------
// Copyright (c) 2022-present Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2022-present Detlef Stern
//-----------------------------------------------------------------------------

package encoder

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

	"t73f.de/r/sx"
	"t73f.de/r/zsc/domain/meta"
	"t73f.de/r/zsc/sz"
	"t73f.de/r/zsx"

	"zettelstore.de/z/internal/ast"
)

// NewSzTransformer returns a new transformer to create s-expressions from AST nodes.
func NewSzTransformer() SzTransformer {
	return SzTransformer{}
}

// SzTransformer contains all data needed to transform into a s-expression.
type SzTransformer struct {
	inVerse bool
}

// GetSz transforms the given node into a sx list.
func (t *SzTransformer) GetSz(node ast.Node) *sx.Pair {
	switch n := node.(type) {
	case *ast.BlockSlice:
		return zsx.MakeBlockList(t.getBlockList(n))
	case *ast.InlineSlice:
		return zsx.MakeInlineList(t.getInlineList(*n))
	case *ast.ParaNode:
		return zsx.MakeParaList(t.getInlineList(n.Inlines))
	case *ast.VerbatimNode:
		return zsx.MakeVerbatim(mapGetS(mapVerbatimKindS, n.Kind), getAttributes(n.Attrs), string(n.Content))
	case *ast.RegionNode:
		return t.getRegion(n)
	case *ast.HeadingNode:
		return zsx.MakeHeading(n.Level, getAttributes(n.Attrs), t.getInlineList(n.Inlines), n.Slug, n.Fragment)
	case *ast.HRuleNode:
		return zsx.MakeThematic(getAttributes(n.Attrs))
	case *ast.NestedListNode:
		return t.getNestedList(n)
	case *ast.DescriptionListNode:
		return t.getDescriptionList(n)
	case *ast.TableNode:
		return t.getTable(n)
	case *ast.TranscludeNode:
		return zsx.MakeTransclusion(getAttributes(n.Attrs), getReference(n.Ref), t.getInlineList(n.Inlines))
	case *ast.BLOBNode:
		return t.getBLOB(n)
	case *ast.TextNode:
		return zsx.MakeText(n.Text)
	case *ast.BreakNode:
		if n.Hard {
			return zsx.MakeHard()
		}
		return zsx.MakeSoft()
	case *ast.LinkNode:
		return t.getLink(n)
	case *ast.EmbedRefNode:
		return zsx.MakeEmbed(getAttributes(n.Attrs), getReference(n.Ref), n.Syntax, t.getInlineList(n.Inlines))
	case *ast.EmbedBLOBNode:
		return t.getEmbedBLOB(n)
	case *ast.CiteNode:
		return zsx.MakeCite(getAttributes(n.Attrs), n.Key, t.getInlineList(n.Inlines))
	case *ast.FootnoteNode:
		return zsx.MakeEndnote(getAttributes(n.Attrs), t.getInlineList(n.Inlines))
	case *ast.MarkNode:
		return zsx.MakeMark(n.Mark, n.Slug, n.Fragment, t.getInlineList(n.Inlines))
	case *ast.FormatNode:
		return zsx.MakeFormat(mapGetS(mapFormatKindS, n.Kind), getAttributes(n.Attrs), t.getInlineList(n.Inlines))
	case *ast.LiteralNode:
		return zsx.MakeLiteral(mapGetS(mapLiteralKindS, n.Kind), getAttributes(n.Attrs), string(n.Content))
	}
	return sx.MakeList(zsx.SymUnknown, sx.MakeString(fmt.Sprintf("%T %v", node, node)))
}

var mapVerbatimKindS = map[ast.VerbatimKind]*sx.Symbol{
	ast.VerbatimZettel:  zsx.SymVerbatimZettel,
	ast.VerbatimCode:    zsx.SymVerbatimCode,
	ast.VerbatimEval:    zsx.SymVerbatimEval,
	ast.VerbatimMath:    zsx.SymVerbatimMath,
	ast.VerbatimComment: zsx.SymVerbatimComment,
	ast.VerbatimHTML:    zsx.SymVerbatimHTML,
}

var mapFormatKindS = map[ast.FormatKind]*sx.Symbol{
	ast.FormatEmph:   zsx.SymFormatEmph,
	ast.FormatStrong: zsx.SymFormatStrong,
	ast.FormatDelete: zsx.SymFormatDelete,
	ast.FormatInsert: zsx.SymFormatInsert,
	ast.FormatSuper:  zsx.SymFormatSuper,
	ast.FormatSub:    zsx.SymFormatSub,
	ast.FormatQuote:  zsx.SymFormatQuote,
	ast.FormatMark:   zsx.SymFormatMark,
	ast.FormatSpan:   zsx.SymFormatSpan,
}

var mapLiteralKindS = map[ast.LiteralKind]*sx.Symbol{
	ast.LiteralCode:    zsx.SymLiteralCode,
	ast.LiteralInput:   zsx.SymLiteralInput,
	ast.LiteralOutput:  zsx.SymLiteralOutput,
	ast.LiteralComment: zsx.SymLiteralComment,
	ast.LiteralMath:    zsx.SymLiteralMath,
}

var mapRegionKindS = map[ast.RegionKind]*sx.Symbol{
	ast.RegionSpan:  zsx.SymRegionBlock,
	ast.RegionQuote: zsx.SymRegionQuote,
	ast.RegionVerse: zsx.SymRegionVerse,
}

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

var mapNestedListKindS = map[ast.NestedListKind]*sx.Symbol{
	ast.NestedListOrdered:   zsx.SymListOrdered,
	ast.NestedListUnordered: zsx.SymListUnordered,
	ast.NestedListQuote:     zsx.SymListQuote,
}

func (t *SzTransformer) getNestedList(ln *ast.NestedListNode) *sx.Pair {
	var items sx.ListBuilder
	isCompact := isCompactList(ln.Items)
	for _, item := range ln.Items {
		if isCompact && len(item) > 0 {
			paragraph := t.GetSz(item[0])
			items.Add(zsx.MakeInlineList(paragraph.Tail()))
			continue
		}
		var itemObjs sx.ListBuilder
		for _, in := range item {
			itemObjs.Add(t.GetSz(in))
		}
		if isCompact {
			items.Add(zsx.MakeInlineList(itemObjs.List()))
		} else {
			items.Add(zsx.MakeBlockList(itemObjs.List()))
		}
	}
	return zsx.MakeList(mapGetS(mapNestedListKindS, ln.Kind), getAttributes(ln.Attrs), items.List())
}
func isCompactList(itemSlice []ast.ItemSlice) bool {
	for _, items := range itemSlice {
		if len(items) > 1 {
			return false
		}
		if len(items) == 1 {
			if _, ok := items[0].(*ast.ParaNode); !ok {
				return false
			}
		}
	}
	return true
}

func (t *SzTransformer) getDescriptionList(dn *ast.DescriptionListNode) *sx.Pair {
	var dlObjs sx.ListBuilder
	for _, def := range dn.Descriptions {
		dlObjs.Add(t.getInlineList(def.Term))
		var descObjs sx.ListBuilder
		for _, b := range def.Descriptions {
			var dVal sx.ListBuilder
			for _, dn := range b {
				dVal.Add(t.GetSz(dn))
			}
			descObjs.Add(zsx.MakeBlockList(dVal.List()))
		}
		dlObjs.Add(zsx.MakeBlockList(descObjs.List()))
	}
	return dlObjs.List().Cons(getAttributes(dn.Attrs)).Cons(zsx.SymDescription)
}

func (t *SzTransformer) getTable(tn *ast.TableNode) *sx.Pair {
	var lb sx.ListBuilder
	lb.AddN(zsx.SymTable, t.getHeader(tn.Header))
	for _, row := range tn.Rows {
		lb.Add(t.getRow(row))
	}
	return lb.List()
}
func (t *SzTransformer) getHeader(header ast.TableRow) *sx.Pair {
	if len(header) == 0 {
		return nil
	}
	return t.getRow(header)
}
func (t *SzTransformer) getRow(row ast.TableRow) *sx.Pair {
	var lb sx.ListBuilder
	for _, cell := range row {
		lb.Add(t.getCell(cell))
	}
	return lb.List()
}

func (t *SzTransformer) getCell(cell *ast.TableCell) *sx.Pair {
	var attrs *sx.Pair
	switch cell.Align {
	case ast.AlignCenter:
		attrs = sx.Cons(sx.Cons(zsx.SymAttrAlign, zsx.AttrAlignCenter), nil)
	case ast.AlignLeft:
		attrs = sx.Cons(sx.Cons(zsx.SymAttrAlign, zsx.AttrAlignLeft), nil)
	case ast.AlignRight:
		attrs = sx.Cons(sx.Cons(zsx.SymAttrAlign, zsx.AttrAlignRight), nil)
	}
	return zsx.MakeCell(attrs, t.getInlineList(cell.Inlines))
}

func (t *SzTransformer) getBLOB(bn *ast.BLOBNode) *sx.Pair {
	var content string
	if bn.Syntax == meta.ValueSyntaxSVG {
		content = string(bn.Blob)
	} else {
		content = getBase64String(bn.Blob)
	}
	return zsx.MakeBLOB(getAttributes(bn.Attrs), t.getInlineList(bn.Description), bn.Syntax, content)
}

func (t *SzTransformer) getLink(ln *ast.LinkNode) *sx.Pair {
	return zsx.MakeLink(
		getAttributes(ln.Attrs),
		getReference(ln.Ref),
		t.getInlineList(ln.Inlines),
	)
}

func (t *SzTransformer) getEmbedBLOB(en *ast.EmbedBLOBNode) *sx.Pair {
	var content string
	if en.Syntax == meta.ValueSyntaxSVG {
		content = string(en.Blob)
	} else {
		content = getBase64String(en.Blob)
	}
	return zsx.MakeEmbedBLOB(getAttributes(en.Attrs), en.Syntax, content, t.getInlineList(en.Inlines))
}

func (t *SzTransformer) getBlockList(bs *ast.BlockSlice) *sx.Pair {
	var lb sx.ListBuilder
	for _, n := range *bs {
		lb.Add(t.GetSz(n))
	}
	return lb.List()
}
func (t *SzTransformer) getInlineList(is ast.InlineSlice) *sx.Pair {
	var lb sx.ListBuilder
	for _, n := range is {
		lb.Add(t.GetSz(n))
	}
	return lb.List()
}

func getAttributes(a zsx.Attributes) *sx.Pair {
	if a.IsEmpty() {
		return sx.Nil()
	}
	keys := a.Keys()
	var lb sx.ListBuilder
	for _, k := range keys {
		lb.Add(sx.Cons(sx.MakeString(k), sx.MakeString(a[k])))
	}
	return lb.List()
}

var mapRefStateS = map[ast.RefState]*sx.Symbol{
	ast.RefStateInvalid:  zsx.SymRefStateInvalid,
	ast.RefStateZettel:   sz.SymRefStateZettel,
	ast.RefStateSelf:     zsx.SymRefStateSelf,
	ast.RefStateFound:    sz.SymRefStateFound,
	ast.RefStateBroken:   sz.SymRefStateBroken,
	ast.RefStateHosted:   zsx.SymRefStateHosted,
	ast.RefStateBased:    sz.SymRefStateBased,
	ast.RefStateQuery:    sz.SymRefStateQuery,
	ast.RefStateExternal: zsx.SymRefStateExternal,
}

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

var mapMetaTypeS = map[*meta.DescriptionType]*sx.Symbol{
	meta.TypeCredential: sz.SymTypeCredential,
	meta.TypeEmpty:      sz.SymTypeEmpty,
	meta.TypeID:         sz.SymTypeID,
	meta.TypeIDSet:      sz.SymTypeIDSet,
	meta.TypeNumber:     sz.SymTypeNumber,
	meta.TypeString:     sz.SymTypeString,
	meta.TypeTagSet:     sz.SymTypeTagSet,
	meta.TypeTimestamp:  sz.SymTypeTimestamp,
	meta.TypeURL:        sz.SymTypeURL,
	meta.TypeWord:       sz.SymTypeWord,
}

// GetMeta transforms the given metadata into a sx list.
func (t *SzTransformer) GetMeta(m *meta.Meta) *sx.Pair {
	var lb sx.ListBuilder
	lb.Add(sz.SymMeta)
	for key, val := range m.Computed() {
		ty := m.Type(key)
		symType := mapGetS(mapMetaTypeS, ty)
		var obj sx.Object
		if ty.IsSet {
			var setObjs sx.ListBuilder
			for _, val := range val.AsSlice() {
				setObjs.Add(sx.MakeString(val))
			}
			obj = setObjs.List()
		} else {
			obj = sx.MakeString(string(val))
		}
		lb.Add(sx.Nil().Cons(obj).Cons(sx.MakeSymbol(key)).Cons(symType))
	}
	return lb.List()
}

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

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

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

import (
	"io"
	"iter"


	"t73f.de/r/zsc/domain/meta"

	"t73f.de/r/zsx/input"

	"zettelstore.de/z/internal/ast"
)

// TextEncoder encodes just the text and ignores any formatting.
type TextEncoder struct{}

// WriteZettel writes metadata and content.
func (te *TextEncoder) WriteZettel(w io.Writer, zn *ast.ZettelNode) (int, error) {
	v := newTextVisitor(w)
	_, _ = te.WriteMeta(&v.b, zn.InhMeta)
	v.visitBlockSlice(&zn.BlocksAST)
	length, err := v.b.Flush()
	return length, err
}

// WriteMeta encodes metadata as text.
func (te *TextEncoder) WriteMeta(w io.Writer, m *meta.Meta) (int, error) {
	buf := newEncWriter(w)
	for key, val := range m.Computed() {
		if meta.Type(key) == meta.TypeTagSet {
			writeTagSet(&buf, val.Elems())
		} else {
			buf.WriteString(string(val))
		}
		buf.WriteLn()
	}
	length, err := buf.Flush()
	return length, err
}

func writeTagSet(buf *encWriter, tags iter.Seq[meta.Value]) {
	first := true
	for tag := range tags {
		if !first {
			buf.WriteSpace()
		}
		first = false
		buf.WriteString(string(tag.CleanTag()))
	}

}

// WriteBlocks writes the content of a block slice to the writer.
func (*TextEncoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {
	v := newTextVisitor(w)
	v.visitBlockSlice(bs)
	length, err := v.b.Flush()
	return length, err
}

// WriteInlines writes an inline slice to the writer
func (*TextEncoder) WriteInlines(w io.Writer, is *ast.InlineSlice) (int, error) {
	v := newTextVisitor(w)
	ast.Walk(&v, is)
	length, err := v.b.Flush()
	return length, err
}

// textVisitor writes the abstract syntax tree to an io.Writer.
type textVisitor struct {
	b         encWriter
	inlinePos int
}

func newTextVisitor(w io.Writer) textVisitor {
	return textVisitor{b: newEncWriter(w)}
}

func (v *textVisitor) Visit(node ast.Node) ast.Visitor {
	switch n := node.(type) {
	case *ast.BlockSlice:
		v.visitBlockSlice(n)
		return nil
	case *ast.InlineSlice:
		v.visitInlineSlice(n)
		return nil
	case *ast.VerbatimNode:
		v.visitVerbatim(n)
		return nil
	case *ast.RegionNode:
		v.visitBlockSlice(&n.Blocks)
		if len(n.Inlines) > 0 {
			v.b.WriteLn()
			ast.Walk(v, &n.Inlines)
		}
		return nil
	case *ast.NestedListNode:
		v.visitNestedList(n)
		return nil
	case *ast.DescriptionListNode:
		v.visitDescriptionList(n)
		return nil
	case *ast.TableNode:
		v.visitTable(n)
		return nil
	case *ast.TranscludeNode:
		ast.Walk(v, &n.Inlines)
	case *ast.BLOBNode:
		return nil
	case *ast.TextNode:
		v.visitText(n.Text)
		return nil
	case *ast.BreakNode:
		if n.Hard {
			v.b.WriteLn()
		} else {
			v.b.WriteSpace()
		}
		return nil
	case *ast.LinkNode:
		if len(n.Inlines) > 0 {
			ast.Walk(v, &n.Inlines)
		}
		return nil
	case *ast.MarkNode:
		if len(n.Inlines) > 0 {
			ast.Walk(v, &n.Inlines)
		}
		return nil
	case *ast.FootnoteNode:
		if v.inlinePos > 0 {
			v.b.WriteSpace()
		}
		// No 'return nil' to write text
	case *ast.LiteralNode:
		if n.Kind != ast.LiteralComment {
			_, _ = v.b.Write(n.Content)
		}
	}
	return v
}

func (v *textVisitor) visitVerbatim(vn *ast.VerbatimNode) {
	if vn.Kind != ast.VerbatimComment {
		_, _ = v.b.Write(vn.Content)
	}
}

func (v *textVisitor) visitNestedList(ln *ast.NestedListNode) {
	for i, item := range ln.Items {
		v.writePosChar(i, '\n')
		for j, it := range item {
			v.writePosChar(j, '\n')
			ast.Walk(v, it)
		}
	}
}

func (v *textVisitor) visitDescriptionList(dl *ast.DescriptionListNode) {
	for i, descr := range dl.Descriptions {
		v.writePosChar(i, '\n')
		ast.Walk(v, &descr.Term)
		for _, b := range descr.Descriptions {
			v.b.WriteLn()
			for k, d := range b {
				v.writePosChar(k, '\n')
				ast.Walk(v, d)
			}
		}
	}
}

func (v *textVisitor) visitTable(tn *ast.TableNode) {
	if len(tn.Header) > 0 {
		v.writeRow(tn.Header)
		v.b.WriteLn()
	}
	for i, row := range tn.Rows {
		v.writePosChar(i, '\n')
		v.writeRow(row)
	}
}

func (v *textVisitor) writeRow(row ast.TableRow) {
	for i, cell := range row {
		v.writePosChar(i, ' ')
		ast.Walk(v, &cell.Inlines)
	}
}

func (v *textVisitor) visitBlockSlice(bs *ast.BlockSlice) {
	for i, bn := range *bs {
		v.writePosChar(i, '\n')
		ast.Walk(v, bn)
	}
}

func (v *textVisitor) visitInlineSlice(is *ast.InlineSlice) {
	for i, in := range *is {
		v.inlinePos = i
		ast.Walk(v, in)
	}
	v.inlinePos = 0
}

func (v *textVisitor) visitText(s string) {
	spaceFound := false
	for _, ch := range s {
		if input.IsSpace(ch) {
			if !spaceFound {
				v.b.WriteSpace()
				spaceFound = true
			}
			continue
		}
		spaceFound = false
		v.b.WriteString(string(ch))
	}
}










func (v *textVisitor) writePosChar(pos int, ch byte) {






	if pos > 0 {





















































		_ = v.b.WriteByte(ch)
	}

}

// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package encoder

import (
	"encoding/base64"
	"io"


)

// encWriter is a specialized writer for encoding zettel.
type encWriter struct {
	w      io.Writer // The io.Writer to write to
	err    error     // Collect error
	length int       // Collected length
}

// newEncWriter creates a new encWriter
func newEncWriter(w io.Writer) encWriter { return encWriter{w: w} }

// Write writes the content of p.
func (w *encWriter) Write(p []byte) (l int, err error) {
	if w.err != nil {
		return 0, w.err
	}
	l, w.err = w.w.Write(p)
	w.length += l
	return l, w.err
}

// WriteString writes the content of s.
func (w *encWriter) WriteString(s string) {
	if w.err != nil {
		return
	}
	var l int
	l, w.err = io.WriteString(w.w, s)
	w.length += l
}

// WriteStrings writes the content of sl.
func (w *encWriter) WriteStrings(sl ...string) {
	for _, s := range sl {
		w.WriteString(s)
	}
}

// WriteByte writes the content of b.
func (w *encWriter) WriteByte(b byte) error {
	var l int
	l, w.err = w.Write([]byte{b})
	w.length += l

	return w.err
}

// WriteBytes writes the content of bs.
func (w *encWriter) WriteBytes(bs ...byte) { _, _ = w.Write(bs) }

// WriteBase64 writes the content of p, encoded with base64.
func (w *encWriter) WriteBase64(p []byte) {
	if w.err == nil {
		encoder := base64.NewEncoder(base64.StdEncoding, w.w)
		var l int
		l, w.err = encoder.Write(p)
		w.length += l
		err1 := encoder.Close()
		if w.err == nil {
			w.err = err1
		}
	}
}

// WriteLn writes a new line character.
func (w *encWriter) WriteLn() {
	if w.err == nil {
		w.err = w.WriteByte('\n')
	}
}

// WriteLn writes a space character.
func (w *encWriter) WriteSpace() {
	if w.err == nil {
		w.err = w.WriteByte(' ')
	}
}










// Flush returns the collected length and error.
func (w *encWriter) Flush() (int, error) { return w.length, w.err }

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

package encoder

// zmkenc encodes the abstract syntax tree back into Zettelmarkup.

import (
	"fmt"
	"io"
	"strings"


	"t73f.de/r/zero/set"
	"t73f.de/r/zsc/domain/meta"

	"t73f.de/r/zsx"

	"zettelstore.de/z/internal/ast"
)

// zmkEncoder contains all data needed for encoding.
type zmkEncoder struct{}

// WriteZettel writes the encoded zettel to the writer.
func (*zmkEncoder) WriteZettel(w io.Writer, zn *ast.ZettelNode) (int, error) {
	v := newZmkVisitor(w)
	v.acceptMeta(zn.InhMeta)
	if zn.InhMeta.YamlSep {
		v.b.WriteString("---\n")
	} else {
		v.b.WriteLn()
	}
	ast.Walk(&v, &zn.BlocksAST)
	length, err := v.b.Flush()
	return length, err
}

// WriteMeta encodes meta data as zmk.
func (*zmkEncoder) WriteMeta(w io.Writer, m *meta.Meta) (int, error) {
	v := newZmkVisitor(w)
	v.acceptMeta(m)
	length, err := v.b.Flush()
	return length, err
}

func (v *zmkVisitor) acceptMeta(m *meta.Meta) {
	for key, val := range m.Computed() {
		v.b.WriteStrings(key, ": ", string(val), "\n")
	}
}

// WriteBlocks writes the content of a block slice to the writer.
func (*zmkEncoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {
	v := newZmkVisitor(w)
	ast.Walk(&v, bs)
	length, err := v.b.Flush()
	return length, err
}

// zmkVisitor writes the abstract syntax tree to an io.Writer.
type zmkVisitor struct {
	b         encWriter
	textEnc   TextEncoder
	prefix    []byte
	inVerse   bool
	inlinePos int
}

func newZmkVisitor(w io.Writer) zmkVisitor { return zmkVisitor{b: newEncWriter(w)} }




func (v *zmkVisitor) Visit(node ast.Node) ast.Visitor {

	switch n := node.(type) {
	case *ast.BlockSlice:
		v.visitBlockSlice(n)

	case *ast.InlineSlice:
		for i, in := range *n {
			v.inlinePos = i
			ast.Walk(v, in)

		}
		v.inlinePos = 0
	case *ast.VerbatimNode:
		v.visitVerbatim(n)
	case *ast.RegionNode:
		v.visitRegion(n)
	case *ast.HeadingNode:
		v.visitHeading(n)
	case *ast.HRuleNode:
		v.b.WriteString("---")
		v.visitAttributes(n.Attrs)


	case *ast.NestedListNode:
		v.visitNestedList(n)


	case *ast.DescriptionListNode:
		v.visitDescriptionList(n)
	case *ast.TableNode:
		v.visitTable(n)
	case *ast.TranscludeNode:





		v.b.WriteStrings("{{{", n.Ref.String(), "}}}") // FIXME n.Inlines
		v.visitAttributes(n.Attrs)
	case *ast.BLOBNode:


		v.visitBLOB(n)


	case *ast.TextNode:



		v.visitText(n)

	case *ast.BreakNode:
		v.visitBreak(n)
	case *ast.LinkNode:
		v.visitLink(n)
	case *ast.EmbedRefNode:
		v.visitEmbedRef(n)
	case *ast.EmbedBLOBNode:
		v.visitEmbedBLOB(n)
	case *ast.CiteNode:
		v.visitCite(n)
	case *ast.FootnoteNode:
		v.b.WriteString("[^")
		ast.Walk(v, &n.Inlines)
		_ = v.b.WriteByte(']')
		v.visitAttributes(n.Attrs)
	case *ast.MarkNode:
		v.visitMark(n)
	case *ast.FormatNode:
		v.visitFormat(n)
	case *ast.LiteralNode:
		v.visitLiteral(n)
	default:
		return v
	}
	return nil
}

func (v *zmkVisitor) visitBlockSlice(bs *ast.BlockSlice) {
	var lastWasParagraph bool



	for i, bn := range *bs {
		if i > 0 {
			v.b.WriteLn()
			if lastWasParagraph && !v.inVerse {
				if _, ok := bn.(*ast.ParaNode); ok {
					v.b.WriteLn()
				}






			}
		}
		ast.Walk(v, bn)




		_, lastWasParagraph = bn.(*ast.ParaNode)
	}
}







var mapVerbatimKind = map[ast.VerbatimKind]string{
	ast.VerbatimZettel:  "@@@",
	ast.VerbatimComment: "%%%",
	ast.VerbatimHTML:    "@@@", // Attribute is set to {="html"}
	ast.VerbatimCode:    "```",

	ast.VerbatimEval:    "~~~",

	ast.VerbatimMath:    "$$$",



}







func (v *zmkVisitor) visitVerbatim(vn *ast.VerbatimNode) {
	kind, ok := mapVerbatimKind[vn.Kind]
	if !ok {
		panic(fmt.Sprintf("Unknown verbatim kind %d", vn.Kind))
	}
	attrs := vn.Attrs
	if vn.Kind == ast.VerbatimHTML {
		attrs = syntaxToHTML(attrs)

	}



	// TODO: scan cn.Lines to find embedded kind[0]s at beginning
	v.b.WriteString(kind)


	v.visitAttributes(attrs)











	v.b.WriteLn()


	_, _ = v.b.Write(vn.Content)











	v.b.WriteLn()


	v.b.WriteString(kind)

}



var mapRegionKind = map[ast.RegionKind]string{
	ast.RegionSpan:  ":::",
	ast.RegionQuote: "<<<",
	ast.RegionVerse: "\"\"\"",



}

func (v *zmkVisitor) visitRegion(rn *ast.RegionNode) {
	// Scan rn.Blocks for embedded regions to adjust length of regionCode
	kind, ok := mapRegionKind[rn.Kind]


	if !ok {
		panic(fmt.Sprintf("Unknown region kind %d", rn.Kind))


	}
	v.b.WriteString(kind)
	v.visitAttributes(rn.Attrs)




	v.b.WriteLn()
	saveInVerse := v.inVerse
	v.inVerse = rn.Kind == ast.RegionVerse
	ast.Walk(v, &rn.Blocks)
	v.inVerse = saveInVerse
	v.b.WriteLn()














	v.b.WriteString(kind)

	if len(rn.Inlines) > 0 {
		v.b.WriteSpace()



		ast.Walk(v, &rn.Inlines)

	}
}

func (v *zmkVisitor) visitHeading(hn *ast.HeadingNode) {

	const headingSigns = "========= "
	v.b.WriteString(headingSigns[len(headingSigns)-hn.Level-3:])
	ast.Walk(v, &hn.Inlines)
	v.visitAttributes(hn.Attrs)
}

var mapNestedListKind = map[ast.NestedListKind]byte{
	ast.NestedListOrdered:   '#',
	ast.NestedListUnordered: '*',
	ast.NestedListQuote:     '>',
}

func (v *zmkVisitor) visitNestedList(ln *ast.NestedListNode) {
	v.prefix = append(v.prefix, mapNestedListKind[ln.Kind])
	for i, item := range ln.Items {
		if i > 0 {


			v.b.WriteLn()
		}
		_, _ = v.b.Write(v.prefix)
		v.b.WriteSpace()


		for j, in := range item {

			if j > 0 {
				v.b.WriteLn()
				if _, ok := in.(*ast.ParaNode); ok {
					v.writePrefixSpaces()
				}


			}
			ast.Walk(v, in)
		}
	}
	v.prefix = v.prefix[:len(v.prefix)-1]
}

func (v *zmkVisitor) writePrefixSpaces() {
	if prefixLen := len(v.prefix); prefixLen > 0 {
		for i := 0; i <= prefixLen; i++ {


			v.b.WriteSpace()


		}






	}
}

func (v *zmkVisitor) visitDescriptionList(dn *ast.DescriptionListNode) {
	for i, descr := range dn.Descriptions {


		if i > 0 {


			v.b.WriteLn()
		}
		v.b.WriteString("; ")

		ast.Walk(v, &descr.Term)





		for _, b := range descr.Descriptions {
			v.b.WriteString("\n: ")

			for jj, dn := range b {
				if jj > 0 {
					v.b.WriteString("\n\n  ")


				}
				ast.Walk(v, dn)
			}
		}
	}
}

var alignCode = map[ast.Alignment]string{
	ast.AlignDefault: "",
	ast.AlignLeft:    "<",
	ast.AlignCenter:  ":",
	ast.AlignRight:   ">",
}

func (v *zmkVisitor) visitTable(tn *ast.TableNode) {
	if header := tn.Header; len(header) > 0 {
		v.writeTableHeader(header, tn.Align)

		v.b.WriteLn()


	}


	for i, row := range tn.Rows {
		if i > 0 {
			v.b.WriteLn()

		}
		v.writeTableRow(row, tn.Align)
	}










}

func (v *zmkVisitor) writeTableHeader(header ast.TableRow, align []ast.Alignment) {
	for pos, cell := range header {
		v.b.WriteString("|=")
		colAlign := align[pos]
		if cell.Align != colAlign {
			v.b.WriteString(alignCode[cell.Align])
		}
		ast.Walk(v, &cell.Inlines)
		if colAlign != ast.AlignDefault {
			v.b.WriteString(alignCode[colAlign])


		}



	}
}

func (v *zmkVisitor) writeTableRow(row ast.TableRow, align []ast.Alignment) {
	for pos, cell := range row {
		_ = v.b.WriteByte('|')
		if cell.Align != align[pos] {
			v.b.WriteString(alignCode[cell.Align])
		}
		ast.Walk(v, &cell.Inlines)

	}
}

func (v *zmkVisitor) visitBLOB(bn *ast.BLOBNode) {

	if bn.Syntax == meta.ValueSyntaxSVG {
		v.b.WriteStrings("@@@", bn.Syntax, "\n")
		_, _ = v.b.Write(bn.Blob)
		v.b.WriteString("\n@@@\n")
		return
	}
	var sb strings.Builder

	_, _ = v.textEnc.WriteInlines(&sb, &bn.Description)
	v.b.WriteStrings("%% Unable to display BLOB with description '", sb.String(), "' and syntax '", bn.Syntax, "'.")












}

var escapeSeqs = set.New(
	"\\", "__", "**", "~~", "^^", ",,", ">>", `""`, "::", "''", "``", "++", "==", "##",
)

func (v *zmkVisitor) visitText(tn *ast.TextNode) {
	last := 0
	for i := 0; i < len(tn.Text); i++ {
		if b := tn.Text[i]; b == '\\' {
			v.b.WriteString(tn.Text[last:i])
			v.b.WriteBytes('\\', b)
			last = i + 1
			continue
		}
		if i < len(tn.Text)-1 {
			s := tn.Text[i : i+2]
			if escapeSeqs.Contains(s) {
				v.b.WriteString(tn.Text[last:i])
				for j := range len(s) {
					v.b.WriteBytes('\\', s[j])
				}
				i++
				last = i + 1
				continue
			}
		}
	}
	v.b.WriteString(tn.Text[last:])
}

func (v *zmkVisitor) visitBreak(bn *ast.BreakNode) {
	if bn.Hard {
		v.b.WriteString("\\\n")
	} else {
		v.b.WriteLn()
	}
	v.writePrefixSpaces()
}

func (v *zmkVisitor) visitLink(ln *ast.LinkNode) {
	v.b.WriteString("[[")
	if len(ln.Inlines) > 0 {
		ast.Walk(v, &ln.Inlines)
		_ = v.b.WriteByte('|')
	}
	if ln.Ref.State == ast.RefStateBased {
		_ = v.b.WriteByte('/')
	}
	v.b.WriteStrings(ln.Ref.String(), "]]")
}

func (v *zmkVisitor) visitEmbedRef(en *ast.EmbedRefNode) {
	v.b.WriteString("{{")
	if len(en.Inlines) > 0 {
		ast.Walk(v, &en.Inlines)
		_ = v.b.WriteByte('|')
	}
	v.b.WriteStrings(en.Ref.String(), "}}")
}

func (v *zmkVisitor) visitEmbedBLOB(en *ast.EmbedBLOBNode) {
	if en.Syntax == meta.ValueSyntaxSVG {
		v.b.WriteString("@@")
		_, _ = v.b.Write(en.Blob)
		v.b.WriteStrings("@@{=", en.Syntax, "}")
		return
	}
	v.b.WriteString("{{TODO: display inline BLOB}}")
}

func (v *zmkVisitor) visitCite(cn *ast.CiteNode) {
	v.b.WriteStrings("[@", cn.Key)
	if len(cn.Inlines) > 0 {
		v.b.WriteSpace()
		ast.Walk(v, &cn.Inlines)
	}
	_ = v.b.WriteByte(']')
	v.visitAttributes(cn.Attrs)
}

func (v *zmkVisitor) visitMark(mn *ast.MarkNode) {
	v.b.WriteStrings("[!", mn.Mark)
	if len(mn.Inlines) > 0 {
		_ = v.b.WriteByte('|')
		ast.Walk(v, &mn.Inlines)
	}
	_ = v.b.WriteByte(']')

}

var mapFormatKind = map[ast.FormatKind][]byte{
	ast.FormatEmph:   []byte("__"),
	ast.FormatStrong: []byte("**"),
	ast.FormatInsert: []byte(">>"),
	ast.FormatDelete: []byte("~~"),
	ast.FormatSuper:  []byte("^^"),
	ast.FormatSub:    []byte(",,"),
	ast.FormatQuote:  []byte(`""`),
	ast.FormatMark:   []byte("##"),
	ast.FormatSpan:   []byte("::"),
}

func (v *zmkVisitor) visitFormat(fn *ast.FormatNode) {
	kind, ok := mapFormatKind[fn.Kind]
	if !ok {
		panic(fmt.Sprintf("Unknown format kind %d", fn.Kind))
	}
	_, _ = v.b.Write(kind)
	ast.Walk(v, &fn.Inlines)
	_, _ = v.b.Write(kind)
	v.visitAttributes(fn.Attrs)
}

func (v *zmkVisitor) visitLiteral(ln *ast.LiteralNode) {
	switch ln.Kind {
	case ast.LiteralCode:
		v.writeLiteral('`', ln.Attrs, ln.Content)
	case ast.LiteralMath:
		v.b.WriteStrings("$$", string(ln.Content), "$$")
		v.visitAttributes(ln.Attrs)
	case ast.LiteralInput:
		v.writeLiteral('\'', ln.Attrs, ln.Content)
	case ast.LiteralOutput:
		v.writeLiteral('=', ln.Attrs, ln.Content)
	case ast.LiteralComment:
		v.b.WriteString("%%")
		v.visitAttributes(ln.Attrs)
		v.b.WriteSpace()
		_, _ = v.b.Write(ln.Content)
	default:
		panic(fmt.Sprintf("Unknown literal kind %v", ln.Kind))
	}
}

func (v *zmkVisitor) writeLiteral(code byte, a zsx.Attributes, content []byte) {
	v.b.WriteBytes(code, code)
	v.writeEscaped(string(content), code)
	v.b.WriteBytes(code, code)
	v.visitAttributes(a)
}

// visitAttributes write HTML attributes
func (v *zmkVisitor) visitAttributes(a zsx.Attributes) {
	if a.IsEmpty() {
		return
	}
	_ = v.b.WriteByte('{')
	for i, k := range a.Keys() {
		if i > 0 {
			v.b.WriteSpace()
		}
		if k == "-" {
			_ = v.b.WriteByte('-')
			continue
		}
		v.b.WriteString(k)
		if vl := a[k]; len(vl) > 0 {
			v.b.WriteStrings("=\"", vl)

			_ = v.b.WriteByte('"')
		}
	}
	_ = v.b.WriteByte('}')
}

func (v *zmkVisitor) writeEscaped(s string, toEscape byte) {
	last := 0
	for i := range len(s) {
		if b := s[i]; b == toEscape || b == '\\' {
			v.b.WriteString(s[last:i])
			v.b.WriteBytes('\\', b)
			last = i + 1
		}
	}
	v.b.WriteString(s[last:])
}

func syntaxToHTML(a zsx.Attributes) zsx.Attributes {
	return a.Clone().Set("", meta.ValueSyntaxHTML).Remove(meta.KeySyntax)


}