Zettelstore Client

const (
	ZettelCanNone   ZettelRights = 1 << iota
	ZettelCanCreate              // Current user is allowed to create a new zettel
	ZettelCanRead                // Requesting user is allowed to read the zettel
	ZettelCanWrite               // Requesting user is allowed to update the zettel
	ZettelCanRename              // Requesting user is allowed to provide the zettel with a new identifier
	ZettelCanDelete              // Requesting user is allowed to delete the zettel
)
	ZettelMaxRight               // Sentinel value
)

// MetaRights contains the metadata of a zettel, and its rights.
type MetaRights struct {
	Meta   ZettelMeta
	Rights ZettelRights

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

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

// MetaJSON contains the metadata of a zettel.
type MetaJSON struct {
	Meta   ZettelMeta   `json:"meta"`
	Rights ZettelRights `json:"rights"`
}

// ZidMetaJSON contains the identifier and the metadata of a zettel.
type ZidMetaJSON struct {
	ID     ZettelID     `json:"id"`
	Meta   ZettelMeta   `json:"meta"`
	Rights ZettelRights `json:"rights"`
}
// ZidMetaRights contains the identifier, the metadata of a zettel, and its rights.
type ZidMetaRights struct {
	ID     ZettelID
	Meta   ZettelMeta
	Rights ZettelRights

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

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

// ZettelData contains all data for a zettel.
type ZettelData struct {
	Meta     ZettelMeta
	Rights   ZettelRights
	Encoding string
	Content  string
// ZettelJSON contains all data for a zettel, the identifier, the metadata, and the content.
type ZettelJSON struct {
	ID       ZettelID     `json:"id"`
	Meta     ZettelMeta   `json:"meta"`
	Encoding string       `json:"encoding"`
	Content  string       `json:"content"`
	Rights   ZettelRights `json:"rights"`
}

// ZettelContentJSON contains all elements to transfer the content of a zettel.
type ZettelContentJSON struct {
	Encoding string `json:"encoding"`
	Content  string `json:"content"`
}

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

// Aggregate maps metadata keys to list of zettel identifier.
type Aggregate map[string][]ZettelID
// MapMeta maps metadata keys to list of metadata.
type MapMeta map[string][]ZettelID

// MapListJSON specifies the map of metadata key to list of metadata that contains the key.
type MapListJSON struct {
	Map MapMeta `json:"map"`
}

// VersionJSON contains version information.
type VersionJSON struct {
	Major int    `json:"major"`
	Minor int    `json:"minor"`
	Patch int    `json:"patch"`
	Info  string `json:"info"`
	Hash  string `json:"hash"`
}

	ZidBoxManager           = ZettelID("00000000000020")
	ZidMetadataKey          = ZettelID("00000000000090")
	ZidParser               = ZettelID("00000000000092")
	ZidStartupConfiguration = ZettelID("00000000000096")
	ZidConfiguration        = ZettelID("00000000000100")

	// WebUI HTML templates are in the range 10000..19999
	ZidBaseTemplate   = ZettelID("00000000010100")
	ZidLoginTemplate  = ZettelID("00000000010200")
	ZidListTemplate   = ZettelID("00000000010300")
	ZidZettelTemplate = ZettelID("00000000010401")
	ZidInfoTemplate   = ZettelID("00000000010402")
	ZidFormTemplate   = ZettelID("00000000010403")
	ZidRenameTemplate = ZettelID("00000000010404")
	ZidBaseTemplate    = ZettelID("00000000010100")
	ZidLoginTemplate   = ZettelID("00000000010200")
	ZidListTemplate    = ZettelID("00000000010300")
	ZidZettelTemplate  = ZettelID("00000000010401")
	ZidInfoTemplate    = ZettelID("00000000010402")
	ZidFormTemplate    = ZettelID("00000000010403")
	ZidRenameTemplate  = ZettelID("00000000010404")
	ZidDeleteTemplate = ZettelID("00000000010405")
	ZidErrorTemplate  = ZettelID("00000000010700")
	ZidDeleteTemplate  = ZettelID("00000000010405")

	// WebUI sxn code zettel are in the range 19000..19999
	ZidSxnStart = ZettelID("00000000019000")
	ZidSxnBase  = ZettelID("00000000019990")
	ZidContextTemplate = ZettelID("00000000010406")
	ZidErrorTemplate   = ZettelID("00000000010700")

	// CSS-related zettel are in the range 20000..29999
	ZidBaseCSS = ZettelID("00000000020001")
	ZidUserCSS = ZettelID("00000000025001")
	ZidBaseCSS    = ZettelID("00000000020001")
	ZidUserCSS    = ZettelID("00000000025001")
	ZidRoleCSSMap = ZettelID("00000000029000") // Maps roles to CSS zettel, which should be in the range 29001..29999.

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

	// WebUI image zettel are in the range 40000..49999
	ZidEmoji = ZettelID("00000000040001")

	// Other sxn code zettel are in the range 50000..59999
	ZidSxnPrelude = ZettelID("00000000059900")

	// Predefined Zettelmarkup zettel are in the range 60000..69999
	ZidRoleZettelZettel        = ZettelID("00000000060010")
	ZidRoleConfigurationZettel = ZettelID("00000000060020")
	ZidRoleRoleZettel          = ZettelID("00000000060030")
	ZidRoleTagZettel           = ZettelID("00000000060040")

	// Range 90000...99999 is reserved for zettel templates
	ZidTOCNewTemplate    = ZettelID("00000000090000")
	ZidTemplateNewZettel = ZettelID("00000000090001")
	ZidTemplateNewRole   = ZettelID("00000000090004")
	ZidTemplateNewTag    = ZettelID("00000000090003")
	ZidTemplateNewUser   = ZettelID("00000000090002")

	ZidDefaultHome = ZettelID("00010000000000")
)

// LengthZid factors the constant length of a zettel identifier
const LengthZid = len(ZidDefaultHome)

	KeyBack         = "back"
	KeyBackward     = "backward"
	KeyBoxNumber    = "box-number"
	KeyCopyright    = "copyright"
	KeyCreated      = "created"
	KeyCredential   = "credential"
	KeyDead         = "dead"
	KeyExpire       = "expire"
	KeyFolge        = "folge"
	KeyFolgeRole    = "folge-role"
	KeyForward      = "forward"
	KeyLang         = "lang"
	KeyLicense      = "license"
	KeyModified     = "modified"
	KeyPrecursor    = "precursor"
	KeyPredecessor  = "predecessor"
	KeyPublished    = "published"
	KeyQuery        = "query"
	KeyReadOnly     = "read-only"
	KeySubordinates = "subordinates"
	KeySuccessors   = "successors"
	KeySuperior     = "superior"
	KeySummary      = "summary"
	KeyURL          = "url"
	KeyUselessFiles = "useless-files"
	KeyUserID       = "user-id"
	KeyUserRole     = "user-role"
	KeyVisibility   = "visibility"
)

// Predefined Metadata values
const (
	ValueFalse             = "false"
	ValueTrue              = "true"
	ValueLangEN            = "en"
	ValueRoleConfiguration = "configuration"
	ValueRoleTag           = "tag"
	ValueRoleRole          = "role"
	ValueRoleZettel        = "zettel"
	ValueSyntaxCSS         = "css"
	ValueSyntaxDraw        = "draw"
	ValueSyntaxGif         = "gif"
	ValueSyntaxHTML        = "html"
	ValueSyntaxMarkdown    = "markdown"
	ValueSyntaxMD          = "md"
	ValueSyntaxMustache    = "mustache"
	ValueSyntaxNone        = "none"
	ValueSyntaxSVG         = "svg"
	ValueSyntaxSxn         = "sxn"
	ValueSyntaxText        = "text"
	ValueSyntaxZmk         = "zmk"
	ValueUserRoleCreator   = "creator"
	ValueUserRoleOwner     = "owner"
	ValueUserRoleReader    = "reader"
	ValueUserRoleWriter    = "writer"
	ValueVisibilityCreator = "creator"

	HeaderDestination = "Destination"
	HeaderLocation    = "Location"
)

// Values for HTTP query parameter.
const (
	QueryKeyCommand   = "cmd"
	QueryKeyCost      = "cost"
	QueryKeyDir       = "dir"
	QueryKeyEncoding  = "enc"
	QueryKeyParseOnly = "parseonly"
	QueryKeyLimit     = "limit"
	QueryKeyPart      = "part"
	QueryKeyPhrase    = "phrase"
	QueryKeyQuery     = "q"
	QueryKeyRole      = "role"
	QueryKeySeed      = "_seed"
)
	QueryKeyTag       = "tag"

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

// Supported encoding values.
const (
	EncodingHTML  = "html"
	EncodingMD    = "md"
	EncodingSexpr = "sexpr"
	EncodingSHTML = "shtml"
	EncodingSz    = "sz"
	EncodingText  = "text"
	EncodingZMK   = "zmk"

	EncodingPlain = "plain"
	EncodingData  = "data"
	EncodingJson  = "json"
)

var mapEncodingEnum = map[string]EncodingEnum{
	EncodingHTML:  EncoderHTML,
	EncodingMD:    EncoderMD,
	EncodingSexpr: EncoderSexpr,
	EncodingSHTML: EncoderSHTML,
	EncodingSz:    EncoderSz,
	EncodingText:  EncoderText,
	EncodingZMK:   EncoderZmk,

	EncodingPlain: EncoderPlain,
	EncodingData:  EncoderData,
	EncodingJson:  EncoderJson,
}
var mapEnumEncoding = map[EncodingEnum]string{}

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

type EncodingEnum uint8

// Values for EncoderEnum
const (
	EncoderUnknown EncodingEnum = iota
	EncoderHTML
	EncoderMD
	EncoderSHTML
	EncoderSz
	EncoderSexpr
	EncoderSHTML
	EncoderText
	EncoderZmk

	EncoderPlain
	EncoderData
	EncoderJson
)

// String representation of an encoder key.
func (e EncodingEnum) String() string {
	if f, ok := mapEnumEncoding[e]; ok {
		return f
	}

const (
	CommandAuthenticated = Command("authenticated")
	CommandRefresh       = Command("refresh")
)

// Supported search operator representations
const (
	BackwardDirective = "BACKWARD"
	ContextDirective  = "CONTEXT"
	CostDirective     = "COST"
	ForwardDirective  = "FORWARD"
	IdentDirective    = "IDENT"
	ItemsDirective    = "ITEMS"
	MaxDirective      = "MAX"
	LimitDirective    = "LIMIT"
	OffsetDirective   = "OFFSET"
	OrDirective       = "OR"
	OrderDirective    = "ORDER"
	PhraseDirective   = "PHRASE"
	PickDirective     = "PICK"
	RandomDirective   = "RANDOM"
	ReverseDirective  = "REVERSE"
	UnlinkedDirective = "UNLINKED"

	ActionSeparator = "|"
	ActionSeparator        = "|"

	ExistOperator    = "?"
	ExistNotOperator = "!?"
	ExistOperator          = "?"
	ExistNotOperator       = "!?"

	SearchOperatorNot        = "!"
	SearchOperatorNot      = "!"
	SearchOperatorEqual      = "="
	SearchOperatorNotEqual   = "!="
	SearchOperatorHas        = ":"
	SearchOperatorHasNot     = "!:"
	SearchOperatorPrefix     = "["
	SearchOperatorNoPrefix   = "!["
	SearchOperatorSuffix     = "]"
	SearchOperatorNoSuffix   = "!]"
	SearchOperatorMatch      = "~"
	SearchOperatorNoMatch    = "!~"
	SearchOperatorHas      = ":"
	SearchOperatorHasNot   = "!:"
	SearchOperatorPrefix   = ">"
	SearchOperatorNoPrefix = "!>"
	SearchOperatorSuffix   = "<"
	SearchOperatorNoSuffix = "!<"
	SearchOperatorMatch    = "~"
	SearchOperatorNoMatch  = "!~"
	SearchOperatorLess       = "<"
	SearchOperatorNotLess    = "!<"
	SearchOperatorGreater    = ">"
	SearchOperatorNotGreater = "!>"
)

	ub.rawLocal = ""
	ub.query = append(ub.query, urlQuery{key, value})
	return ub
}

// AppendQuery adds a new query
func (ub *URLBuilder) AppendQuery(value string) *URLBuilder {
	if value != "" {
		ub.rawLocal = ""
		ub.query = append(ub.query, urlQuery{QueryKeyQuery, value})
	ub.rawLocal = ""
	ub.query = append(ub.query, urlQuery{QueryKeyQuery, value})
	}
	return ub
}

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

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

// String produces a string value.
func (ub *URLBuilder) String() string {
	return ub.asString("&")
}

// AttrString returns the string value of the URL suitable to be placed in a HTML attribute.
func (ub *URLBuilder) AttrString() string {
	return ub.asString("&")
}

func (ub *URLBuilder) asString(qsep string) string {
	var sb strings.Builder

	sb.WriteString(ub.prefix)
	if ub.key != '/' {
		sb.WriteByte(ub.key)
	}
	if ub.rawLocal != "" {

		sb.WriteByte('#')
		sb.WriteString(ub.fragment)
	}
	for i, q := range ub.query {
		if i == 0 {
			sb.WriteByte('?')
		} else {
			sb.WriteByte('&')
			sb.WriteString(qsep)
		}
		sb.WriteString(q.key)
		if val := q.val; val != "" {
			sb.WriteByte('=')
			sb.WriteString(url.QueryEscape(val))
		}
	}
	return sb.String()
}

// Package attrs stores attributes of zettel parts.
package attrs

import (
	"strings"

	"zettelstore.de/client.fossil/maps"
	"zettelstore.de/c/maps"
)

// Attributes store additional information about some node types.
type Attributes map[string]string

// IsEmpty returns true if there are no attributes.
func (a Attributes) IsEmpty() bool { return len(a) == 0 }

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

package attrs_test

import (
	"testing"

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

func TestHasDefault(t *testing.T) {
	t.Parallel()
	attr := attrs.Attributes{}
	if attr.HasDefault() {
		t.Error("Should not have default attr")

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

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

	"zettelstore.de/client.fossil/api"
	"codeberg.org/t73fde/sxpf"
	"zettelstore.de/client.fossil/sexp"
	"zettelstore.de/sx.fossil"
	"zettelstore.de/sx.fossil/sxreader"
	"codeberg.org/t73fde/sxpf/reader"
	"zettelstore.de/c/api"
)

// Client contains all data to execute requests.
type Client struct {
	base      string
	username  string
	password  string

				TLSHandshakeTimeout: 5 * time.Second,
			},
		},
	}
	return &c
}

// AllowRedirect will modify the client to not follow redirect status code when
// using the Zettelstore. The original behaviour can be restored by settinh
// "allow" to false.
func (c *Client) AllowRedirect(allow bool) {
	if allow {
		c.client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
			return http.ErrUseLastResponse
		}
	} else {
		c.client.CheckRedirect = nil
	}
}

// Error encapsulates the possible client call errors.
type Error struct {
	StatusCode int
	Message    string
	Body       []byte
}

	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return statusToError(resp)
	}
	rd := sxreader.MakeReader(resp.Body)
	obj, err := rd.Read()
	if err != nil {
	dec := json.NewDecoder(resp.Body)
	var tinfo api.AuthJSON
	err = dec.Decode(&tinfo)
		return err
	}
	vals, err := sexp.ParseList(obj, "ssi")
	if err != nil {
		return err
	}
	token := vals[1].(sx.String).String()
	if len(token) < 4 {
		return fmt.Errorf("no valid token found: %q", token)
	}
	c.token = token
	c.tokenType = vals[0].(sx.String).String()
	c.expires = time.Now().Add(time.Duration(vals[2].(sx.Int64)*9/10) * time.Second)
	c.token = tinfo.Token
	c.tokenType = tinfo.Type
	c.expires = time.Now().Add(time.Duration(tinfo.Expires*10/9) * time.Second)
	return nil
}

func (c *Client) updateToken(ctx context.Context) error {
	if c.username == "" {
		return nil
	}

	}
	if zid := api.ZettelID(b); zid.IsValid() {
		return zid, nil
	}
	return api.InvalidZID, err
}

// CreateZettelData creates a new zettel and returns its URL.
func (c *Client) CreateZettelData(ctx context.Context, data api.ZettelData) (api.ZettelID, error) {
// CreateZettelJSON creates a new zettel and returns its URL.
func (c *Client) CreateZettelJSON(ctx context.Context, data *api.ZettelDataJSON) (api.ZettelID, error) {
	var buf bytes.Buffer
	if _, err := sx.Print(&buf, sexp.EncodeZettel(data)); err != nil {
	if err := encodeZettelData(&buf, data); err != nil {
		return api.InvalidZID, err
	}
	ub := c.newURLBuilder('z').AppendKVQuery(api.QueryKeyEncoding, api.EncodingData)
	ub := c.newURLBuilder('z').AppendKVQuery(api.QueryKeyEncoding, api.EncodingJson)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodPost, ub, &buf, nil)
	if err != nil {
		return api.InvalidZID, err
	}
	defer resp.Body.Close()
	rdr := sxreader.MakeReader(resp.Body)
	obj, err := rdr.Read()
	if resp.StatusCode != http.StatusCreated {
		return api.InvalidZID, statusToError(resp)
	}
	dec := json.NewDecoder(resp.Body)
	var newZid api.ZidJSON
	err = dec.Decode(&newZid)
	if err != nil {
		return api.InvalidZID, err
	}
	if zid := newZid.ID; zid.IsValid() {
	return makeZettelID(obj)
		return zid, nil
	}
	return api.InvalidZID, err
}

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

var bsLF = []byte{'\n'}

// QueryZettel returns a list of all Zettel.
func (c *Client) QueryZettel(ctx context.Context, query string) ([][]byte, error) {
// ListZettel returns a list of all Zettel.
func (c *Client) ListZettel(ctx context.Context, query string) ([][]byte, error) {
	ub := c.newURLBuilder('z').AppendQuery(query)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	data, err := io.ReadAll(resp.Body)
	switch resp.StatusCode {
	case http.StatusOK:
	case http.StatusNoContent:
		return nil, nil
	default:
		return nil, statusToError(resp)
	}
	data, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}
	lines := bytes.Split(data, bsLF)
	if len(lines[len(lines)-1]) == 0 {
		lines = lines[:len(lines)-1]
	}
	return lines, nil
}

// QueryZettelData returns a list of zettel metadata.
func (c *Client) QueryZettelData(ctx context.Context, query string) (string, string, []api.ZidMetaRights, error) {
	ub := c.newURLBuilder('z').AppendKVQuery(api.QueryKeyEncoding, api.EncodingData).AppendQuery(query)
// ListZettelJSON returns a list of zettel.
func (c *Client) ListZettelJSON(ctx context.Context, query string) (string, string, []api.ZidMetaJSON, error) {
	ub := c.newURLBuilder('z').AppendKVQuery(api.QueryKeyEncoding, api.EncodingJson).AppendQuery(query)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return "", "", nil, err
	}
	defer resp.Body.Close()
	rdr := sxreader.MakeReader(resp.Body)
	obj, err := rdr.Read()
	switch resp.StatusCode {
	if resp.StatusCode != http.StatusOK {
	case http.StatusOK:
	case http.StatusNoContent:
		return "", "", nil, nil
	default:
		return "", "", nil, statusToError(resp)
	}
	if err != nil {
		return "", "", nil, err
	}
	vals, err := sexp.ParseList(obj, "yppp")
	if err != nil {
		return "", "", nil, err
	}
	qVals, err := sexp.ParseList(vals[1], "ys")
	if err != nil {
		return "", "", nil, err
	}
	hVals, err := sexp.ParseList(vals[2], "ys")
	if err != nil {
		return "", "", nil, err
	}
	metaList, err := parseMetaList(vals[3].(*sx.Pair))
	return qVals[1].String(), hVals[1].String(), metaList, err
}

	dec := json.NewDecoder(resp.Body)
func parseMetaList(metaPair *sx.Pair) ([]api.ZidMetaRights, error) {
	if metaPair == nil {
		return nil, fmt.Errorf("no zettel list")
	}
	if errSym := sexp.CheckSymbol(metaPair.Car(), "list"); errSym != nil {
		return nil, errSym
	}
	var result []api.ZidMetaRights
	for node := metaPair.Cdr(); !sx.IsNil(node); {
		elem, isPair := sx.GetPair(node)
		if !isPair {
			return nil, fmt.Errorf("meta-list not a proper list: %v", metaPair.String())
		}
		node = elem.Cdr()
		vals, err := sexp.ParseList(elem.Car(), "yppp")
		if err != nil {
			return nil, err
		}

		if errSym := sexp.CheckSymbol(vals[0], "zettel"); errSym != nil {
			return nil, errSym
		}

		idVals, err := sexp.ParseList(vals[1], "yi")
		if err != nil {
			return nil, err
		}
		if errSym := sexp.CheckSymbol(idVals[0], "id"); errSym != nil {
			return nil, errSym
		}
		zid, err := makeZettelID(idVals[1])
		if err != nil {
			return nil, err
		}

		meta, err := sexp.ParseMeta(vals[2].(*sx.Pair))
		if err != nil {
			return nil, err
		}

		rights, err := sexp.ParseRights(vals[3])
		if err != nil {
			return nil, err
		}

		result = append(result, api.ZidMetaRights{
			ID:     zid,
			Meta:   meta,
			Rights: rights,
		})
	}
	return result, nil
}
func makeZettelID(obj sx.Object) (api.ZettelID, error) {
	val, isInt64 := obj.(sx.Int64)
	if !isInt64 || val <= 0 {
		return api.InvalidZID, fmt.Errorf("invalid zettel ID: %v", val)
	}
	sVal := strconv.FormatInt(int64(val), 10)
	if len(sVal) < 14 {
		sVal = "00000000000000"[0:14-len(sVal)] + sVal
	}
	zid := api.ZettelID(sVal)
	var zl api.ZettelListJSON
	if !zid.IsValid() {
		return api.InvalidZID, fmt.Errorf("invalid zettel ID: %v", val)
	}
	return zid, nil
}

	err = dec.Decode(&zl)
// QueryAggregate returns a aggregate as a result of a query.
// It is most often used in a query with an action, where the action is either
// a metadata key of type Word, WordSet, or TagSet.
func (c *Client) QueryAggregate(ctx context.Context, query string) (api.Aggregate, error) {
	lines, err := c.QueryZettel(ctx, query)
	if err != nil {
		return nil, err
	}
	if len(lines) == 0 {
		return nil, nil
	}
	agg := make(api.Aggregate, len(lines))
	for _, line := range lines {
		if fields := bytes.Fields(line); len(fields) > 1 {
			key := string(fields[0])
			for _, field := range fields[1:] {
				if zid := api.ZettelID(string(field)); zid.IsValid() {
					agg[key] = append(agg[key], zid)
				}
			}
		}
	}
	return agg, nil
}

// TagZettel returns the tag zettel of a given tag.
//
// This method only works if c.AllowRedirect(true) was called.
func (c *Client) TagZettel(ctx context.Context, tag string) (api.ZettelID, error) {
	return c.fetchTagOrRoleZettel(ctx, api.QueryKeyTag, tag)
}

// RoleZettel returns the tag zettel of a given tag.
//
// This method only works if c.AllowRedirect(true) was called.
func (c *Client) RoleZettel(ctx context.Context, role string) (api.ZettelID, error) {
	return c.fetchTagOrRoleZettel(ctx, api.QueryKeyRole, role)
}

func (c *Client) fetchTagOrRoleZettel(ctx context.Context, key, val string) (api.ZettelID, error) {
	if c.client.CheckRedirect == nil {
		panic("client does not allow to track redirect")
	}
	ub := c.newURLBuilder('z').AppendKVQuery(key, val)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return api.InvalidZID, err
	}
	defer resp.Body.Close()
	data, err := io.ReadAll(resp.Body)
	if err != nil {
		return api.InvalidZID, err
	}

	switch resp.StatusCode {
	case http.StatusNotFound:
		return "", nil
		return "", "", nil, err
	case http.StatusFound:
		zid := api.ZettelID(data)
		if zid.IsValid() {
			return zid, nil
		}
		return api.InvalidZID, nil
	}
	return zl.Query, zl.Human, zl.List, nil
	default:
		return api.InvalidZID, statusToError(resp)
	}
}

// GetZettel returns a zettel as a string.
func (c *Client) GetZettel(ctx context.Context, zid api.ZettelID, part string) ([]byte, error) {
	ub := c.newURLBuilder('z').SetZid(zid)
	if part != "" && part != api.PartContent {
		ub.AppendKVQuery(api.QueryKeyPart, part)
	}
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	data, err := io.ReadAll(resp.Body)
	switch resp.StatusCode {
	case http.StatusOK:
	case http.StatusNoContent:
		return nil, nil
	default:
		return nil, statusToError(resp)
	}
	return data, err
	return io.ReadAll(resp.Body)
}

// GetZettelData returns a zettel as a struct of its parts.
func (c *Client) GetZettelData(ctx context.Context, zid api.ZettelID) (api.ZettelData, error) {
// GetZettelJSON returns a zettel as a JSON struct.
func (c *Client) GetZettelJSON(ctx context.Context, zid api.ZettelID) (*api.ZettelDataJSON, error) {
	ub := c.newURLBuilder('z').SetZid(zid)
	ub.AppendKVQuery(api.QueryKeyEncoding, api.EncodingData)
	ub.AppendKVQuery(api.QueryKeyEncoding, api.EncodingJson)
	ub.AppendKVQuery(api.QueryKeyPart, api.PartZettel)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err == nil {
		defer resp.Body.Close()
		if resp.StatusCode != http.StatusOK {
			return api.ZettelData{}, statusToError(resp)
		}
		rdr := sxreader.MakeReader(resp.Body)
		obj, err2 := rdr.Read()
		if err2 == nil {
			return sexp.ParseZettel(obj)
		}
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, statusToError(resp)
	}
	dec := json.NewDecoder(resp.Body)
	var out api.ZettelDataJSON
	err = dec.Decode(&out)
	if err != nil {
		return nil, err
	}
	}
	return api.ZettelData{}, err
	return &out, nil
}

// GetParsedZettel return a parsed zettel in a defined encoding.
func (c *Client) GetParsedZettel(ctx context.Context, zid api.ZettelID, enc api.EncodingEnum) ([]byte, error) {
	return c.getZettelString(ctx, zid, enc, true)
}

	case http.StatusNoContent:
	default:
		return nil, statusToError(resp)
	}
	return io.ReadAll(resp.Body)
}

// GetParsedSz returns an parsed zettel as a Sexpr-decoded data structure.
func (c *Client) GetParsedSz(ctx context.Context, zid api.ZettelID, part string, sf sx.SymbolFactory) (sx.Object, error) {
	return c.getSz(ctx, zid, part, true, sf)
// GetParsedSexpr returns an parsed zettel as a Sexpr-decoded data structure.
func (c *Client) GetParsedSexpr(ctx context.Context, zid api.ZettelID, part string, sf sxpf.SymbolFactory) (sxpf.Object, error) {
	return c.getSexpr(ctx, zid, part, true, sf)
}

// GetEvaluatedSz returns an evaluated zettel as a Sexpr-decoded data structure.
func (c *Client) GetEvaluatedSz(ctx context.Context, zid api.ZettelID, part string, sf sx.SymbolFactory) (sx.Object, error) {
	return c.getSz(ctx, zid, part, false, sf)
// GetEvaluatedSexpr returns an evaluated zettel as a Sexpr-decoded data structure.
func (c *Client) GetEvaluatedSexpr(ctx context.Context, zid api.ZettelID, part string, sf sxpf.SymbolFactory) (sxpf.Object, error) {
	return c.getSexpr(ctx, zid, part, false, sf)
}

func (c *Client) getSz(ctx context.Context, zid api.ZettelID, part string, parseOnly bool, sf sx.SymbolFactory) (sx.Object, error) {
func (c *Client) getSexpr(ctx context.Context, zid api.ZettelID, part string, parseOnly bool, sf sxpf.SymbolFactory) (sxpf.Object, error) {
	ub := c.newURLBuilder('z').SetZid(zid)
	ub.AppendKVQuery(api.QueryKeyEncoding, api.EncodingSz)
	ub.AppendKVQuery(api.QueryKeyEncoding, api.EncodingSexpr)
	if part != "" {
		ub.AppendKVQuery(api.QueryKeyPart, part)
	}
	if parseOnly {
		ub.AppendKVQuery(api.QueryKeyParseOnly, "")
	}
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, statusToError(resp)
	}
	return sxreader.MakeReader(bufio.NewReaderSize(resp.Body, 8), sxreader.WithSymbolFactory(sf)).Read()
	return reader.MakeReader(bufio.NewReaderSize(resp.Body, 8), reader.WithSymbolFactory(sf)).Read()
}

// GetMetaData returns the metadata of a zettel.
func (c *Client) GetMetaData(ctx context.Context, zid api.ZettelID) (api.MetaRights, error) {
// GetMeta returns the metadata of a zettel.
func (c *Client) GetMeta(ctx context.Context, zid api.ZettelID) (api.ZettelMeta, error) {
	ub := c.newURLBuilder('z').SetZid(zid)
	ub.AppendKVQuery(api.QueryKeyEncoding, api.EncodingData)
	ub.AppendKVQuery(api.QueryKeyEncoding, api.EncodingJson)
	ub.AppendKVQuery(api.QueryKeyPart, api.PartMeta)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return api.MetaRights{}, err
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, statusToError(resp)
	}
	dec := json.NewDecoder(resp.Body)
	var out api.MetaJSON
	err = dec.Decode(&out)
	if err != nil {
		return nil, err
	}
	return out.Meta, nil
}

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

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

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

// GetZettelContext returns metadata of the given zettel and, more important,
// metadata of zettel that for the context of the first zettel.
func (c *Client) GetZettelContext(
	ctx context.Context, zid api.ZettelID, dir ContextDirection, cost, limit int) (
	*api.ZidMetaRelatedList, error,
) {
	ub := c.newURLBuilder('x').SetZid(zid)
	switch dir {
	case DirBackward:
		ub.AppendKVQuery(api.QueryKeyDir, api.DirBackward)
	case DirForward:
		ub.AppendKVQuery(api.QueryKeyDir, api.DirForward)
	}
	if cost > 0 {
		ub.AppendKVQuery(api.QueryKeyCost, strconv.Itoa(cost))
	}
	if limit > 0 {
		ub.AppendKVQuery(api.QueryKeyLimit, strconv.Itoa(limit))
	}
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	rdr := sxreader.MakeReader(resp.Body)
	obj, err := rdr.Read()
	if resp.StatusCode != http.StatusOK {
		return api.MetaRights{}, statusToError(resp)
		return nil, statusToError(resp)
	}
	dec := json.NewDecoder(resp.Body)
	var out api.ZidMetaRelatedList
	err = dec.Decode(&out)
	if err != nil {
		return api.MetaRights{}, err
		return nil, err
	}
	vals, err := sexp.ParseList(obj, "ypp")
	if err != nil {
		return api.MetaRights{}, err
	}
	return &out, nil
}
	if errSym := sexp.CheckSymbol(vals[0], "list"); errSym != nil {
		return api.MetaRights{}, err
	}

	meta, err := sexp.ParseMeta(vals[1].(*sx.Pair))

// GetUnlinkedReferences returns connections to other zettel, embedded material, externals URLs.
func (c *Client) GetUnlinkedReferences(
	ctx context.Context, zid api.ZettelID, query url.Values) (*api.ZidMetaRelatedList, error) {
	ub := c.newQueryURLBuilder('u', query).SetZid(zid)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, ub, nil, nil)
	if err != nil {
		return api.MetaRights{}, err
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, statusToError(resp)

	rights, err := sexp.ParseRights(vals[2])
	}
	dec := json.NewDecoder(resp.Body)
	var out api.ZidMetaRelatedList
	err = dec.Decode(&out)
	if err != nil {
		return api.MetaRights{}, err
		return nil, err
	}

	return api.MetaRights{
		Meta:   meta,
		Rights: rights,
	}, nil
	return &out, nil
}

// UpdateZettel updates an existing zettel.
func (c *Client) UpdateZettel(ctx context.Context, zid api.ZettelID, data []byte) error {
	ub := c.newURLBuilder('z').SetZid(zid)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodPut, ub, bytes.NewBuffer(data), nil)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNoContent {
		return statusToError(resp)
	}
	return nil
}

// UpdateZettelData updates an existing zettel.
func (c *Client) UpdateZettelData(ctx context.Context, zid api.ZettelID, data api.ZettelData) error {
// UpdateZettelJSON updates an existing zettel.
func (c *Client) UpdateZettelJSON(ctx context.Context, zid api.ZettelID, data *api.ZettelDataJSON) error {
	var buf bytes.Buffer
	if _, err := sx.Print(&buf, sexp.EncodeZettel(data)); err != nil {
	if err := encodeZettelData(&buf, data); err != nil {
		return err
	}
	ub := c.newURLBuilder('z').SetZid(zid).AppendKVQuery(api.QueryKeyEncoding, api.EncodingData)
	ub := c.newURLBuilder('z').SetZid(zid).AppendKVQuery(api.QueryKeyEncoding, api.EncodingJson)
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodPut, ub, &buf, nil)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNoContent {
		return statusToError(resp)

	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNoContent {
		return statusToError(resp)
	}
	return nil
}

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

// QueryMapMeta returns a map of all metadata values with the given query action to the
// list of zettel IDs containing this value.
func (c *Client) QueryMapMeta(ctx context.Context, query string) (api.MapMeta, error) {
	err := c.updateToken(ctx)
	if err != nil {
		return nil, err
	}
	req, err := c.newRequest(ctx, http.MethodGet, c.newURLBuilder('z').AppendKVQuery(api.QueryKeyEncoding, api.EncodingJson).AppendQuery(query), nil)
	if err != nil {
		return nil, err
	}
	resp, err := c.executeRequest(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, statusToError(resp)
	}
	dec := json.NewDecoder(resp.Body)
	var mlj api.MapListJSON
	err = dec.Decode(&mlj)
	if err != nil {
		return nil, err
	}
	return mlj.Map, nil
}

// GetVersionInfo returns version information..
func (c *Client) GetVersionInfo(ctx context.Context) (VersionInfo, error) {
// GetVersionJSON returns version information..
func (c *Client) GetVersionJSON(ctx context.Context) (api.VersionJSON, error) {
	resp, err := c.buildAndExecuteRequest(ctx, http.MethodGet, c.newURLBuilder('x'), nil, nil)
	if err != nil {
		return VersionInfo{}, err
		return api.VersionJSON{}, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return VersionInfo{}, statusToError(resp)
		return api.VersionJSON{}, statusToError(resp)
	}
	rdr := sxreader.MakeReader(resp.Body)
	obj, err := rdr.Read()
	if err == nil {
	dec := json.NewDecoder(resp.Body)
	var version api.VersionJSON
	err = dec.Decode(&version)
		if vals, errVals := sexp.ParseList(obj, "iiiss"); errVals == nil {
			return VersionInfo{
				Major: int(vals[0].(sx.Int64)),
				Minor: int(vals[1].(sx.Int64)),
				Patch: int(vals[2].(sx.Int64)),
				Info:  vals[3].(sx.String).String(),
				Hash:  vals[4].(sx.String).String(),
			}, nil
	if err != nil {
		}
	}
	return VersionInfo{}, err
}

		return api.VersionJSON{}, err
	}
	return version, nil
// VersionInfo contains version information.
type VersionInfo struct {
	Major int
	Minor int
	Patch int
	Info  string
	Hash  string
}

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

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/client.fossil/client"
	"zettelstore.de/client.fossil/sz"
	"zettelstore.de/sx.fossil"
	"codeberg.org/t73fde/sxpf"
	"zettelstore.de/c/api"
	"zettelstore.de/c/client"
	"zettelstore.de/c/sexpr"
)

func TestZettelList(t *testing.T) {
	c := getClient()
	_, err := c.QueryZettel(context.Background(), "")
	_, err := c.ListZettel(context.Background(), "")
	if err != nil {
		t.Error(err)
		return
	}
}

func TestGetProtectedZettel(t *testing.T) {
	c := getClient()
	_, err := c.GetZettel(context.Background(), api.ZidStartupConfiguration, api.PartZettel)
	if err != nil {
		if cErr, ok := err.(*client.Error); ok && cErr.StatusCode == http.StatusForbidden {
			return
		} else {
			t.Error(err)
		}
		return
	}
}

func TestGetSzZettel(t *testing.T) {
func TestGetSexprZettel(t *testing.T) {
	c := getClient()
	sf := sx.MakeMappedFactory(1024)
	var zetSyms sz.ZettelSymbols
	sf := sxpf.MakeMappedFactory()
	var zetSyms sexpr.ZettelSymbols
	zetSyms.InitializeZettelSymbols(sf)
	value, err := c.GetEvaluatedSz(context.Background(), api.ZidDefaultHome, api.PartContent, sf)
	value, err := c.GetEvaluatedSexpr(context.Background(), api.ZidDefaultHome, api.PartContent, sf)
	if err != nil {
		t.Error(err)
		return
	}
	if value.IsNil() {
		t.Error("No data")
	}

module zettelstore.de/client.fossil
module zettelstore.de/c

go 1.21
go 1.20

require zettelstore.de/sx.fossil v0.0.0-20231130150648-05ef116ba207
require (
	codeberg.org/t73fde/sxhtml v0.0.0-20230317170051-24321195e197
	codeberg.org/t73fde/sxpf v0.0.0-20230319111333-7de220f3b475
)

zettelstore.de/sx.fossil v0.0.0-20231130150648-05ef116ba207 h1:8ch54z0w53bps6a00NDofEqo3AJ1l7ITXyC3XyLmlY4=
zettelstore.de/sx.fossil v0.0.0-20231130150648-05ef116ba207/go.mod h1:Uw3OLM1ufOM4Xe0G51mvkTDUv2okd+HyDBMx+0ZG7ME=
codeberg.org/t73fde/sxhtml v0.0.0-20230317170051-24321195e197 h1:6kX7TY25agLFlHNvByO1Jc3GrBA7mu7aOa8tCOniUew=
codeberg.org/t73fde/sxhtml v0.0.0-20230317170051-24321195e197/go.mod h1:Dp3EwBSsE3TvdPw9QZ4Wm25ZragluVT2OayRFRiq6jk=
codeberg.org/t73fde/sxpf v0.0.0-20230319111333-7de220f3b475 h1:0OTzV3FYY/Y7YsaVaSzF4Wd17pXzdH6DaSvMeqteJc4=
codeberg.org/t73fde/sxpf v0.0.0-20230319111333-7de220f3b475/go.mod h1:iSbMygOmtRQYp8pryNKYzRuMibYDSR80smU2b6qm1bc=

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

package maps_test

import (
	"testing"

	"zettelstore.de/client.fossil/maps"
	"zettelstore.de/c/maps"
)

func isSorted(seq []string) bool {
	for i := 1; i < len(seq); i++ {
		if seq[i] < seq[i-1] {
			return false
		}

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

// Package sexp contains helper function to work with s-expression in an alien
// environment.
package sexp

import (
	"errors"
	"fmt"
	"sort"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/sx.fossil"
)

// EncodeZettel transforms zettel data into a sx object.
func EncodeZettel(zettel api.ZettelData) sx.Object {
	sf := sx.MakeMappedFactory(1024)
	return sx.MakeList(
		sf.MustMake("zettel"),
		meta2sz(zettel.Meta, sf),
		sx.MakeList(sf.MustMake("rights"), sx.Int64(int64(zettel.Rights))),
		sx.MakeList(sf.MustMake("encoding"), sx.String(zettel.Encoding)),
		sx.MakeList(sf.MustMake("content"), sx.String(zettel.Content)),
	)
}

func ParseZettel(obj sx.Object) (api.ZettelData, error) {
	vals, err := ParseList(obj, "ypppp")
	if err != nil {
		return api.ZettelData{}, err
	}
	if errSym := CheckSymbol(vals[0], "zettel"); errSym != nil {
		return api.ZettelData{}, errSym
	}

	meta, err := ParseMeta(vals[1].(*sx.Pair))
	if err != nil {
		return api.ZettelData{}, err
	}

	rights, err := ParseRights(vals[2])
	if err != nil {
		return api.ZettelData{}, err
	}

	encVals, err := ParseList(vals[3], "ys")
	if err != nil {
		return api.ZettelData{}, err
	}
	if errSym := CheckSymbol(encVals[0], "encoding"); errSym != nil {
		return api.ZettelData{}, errSym
	}

	contentVals, err := ParseList(vals[4], "ys")
	if err != nil {
		return api.ZettelData{}, err
	}
	if errSym := CheckSymbol(contentVals[0], "content"); errSym != nil {
		return api.ZettelData{}, errSym
	}

	return api.ZettelData{
		Meta:     meta,
		Rights:   rights,
		Encoding: encVals[1].(sx.String).String(),
		Content:  contentVals[1].(sx.String).String(),
	}, nil
}

// EncodeMetaRights translates metadata/rights into a sx object.
func EncodeMetaRights(mr api.MetaRights) *sx.Pair {
	sf := sx.MakeMappedFactory(1024)
	return sx.MakeList(
		sf.MustMake("list"),
		meta2sz(mr.Meta, sf),
		sx.MakeList(sf.MustMake("rights"), sx.Int64(int64(mr.Rights))),
	)
}

func meta2sz(m api.ZettelMeta, sf sx.SymbolFactory) sx.Object {
	result := sx.Nil().Cons(sf.MustMake("meta"))
	curr := result
	keys := make([]string, 0, len(m))
	for k := range m {
		keys = append(keys, k)
	}
	sort.Strings(keys)
	for _, k := range keys {
		val := sx.MakeList(sf.MustMake(k), sx.String(m[k]))
		curr = curr.AppendBang(val)
	}
	return result
}

// ParseMeta translates the given list to metadata.
func ParseMeta(pair *sx.Pair) (api.ZettelMeta, error) {
	if err := CheckSymbol(pair.Car(), "meta"); err != nil {
		return nil, err
	}
	res := api.ZettelMeta{}
	for node := pair.Tail(); node != nil; node = node.Tail() {
		mVals, err := ParseList(node.Car(), "ys")
		if err != nil {
			return nil, err
		}
		res[mVals[0].(*sx.Symbol).Name()] = mVals[1].(sx.String).String()
	}
	return res, nil
}

// ParseRights returns the rights values of the given object.
func ParseRights(obj sx.Object) (api.ZettelRights, error) {
	rVals, err := ParseList(obj, "yi")
	if err != nil {
		return api.ZettelMaxRight, err
	}
	if errSym := CheckSymbol(rVals[0], "rights"); errSym != nil {
		return api.ZettelMaxRight, errSym
	}
	i64 := int64(rVals[1].(sx.Int64))
	if i64 < 0 && i64 >= int64(api.ZettelMaxRight) {
		return api.ZettelMaxRight, fmt.Errorf("invalid zettel right value: %v", i64)
	}
	return api.ZettelRights(i64), nil
}

// ParseList parses the given object as a proper list, based on a type specification.
func ParseList(obj sx.Object, spec string) ([]sx.Object, error) {
	pair, isPair := sx.GetPair(obj)
	if !isPair {
		return nil, fmt.Errorf("not a list: %T/%v", obj, obj)
	}
	if pair == nil {
		if spec == "" {
			return nil, nil
		}
		return nil, ErrElementsMissing
	}

	result := make([]sx.Object, 0, len(spec))
	node, i := pair, 0
	for ; node != nil; i++ {
		if i >= len(spec) {
			return nil, ErrNoSpec
		}
		var val sx.Object
		var ok bool
		car := node.Car()
		switch spec[i] {
		case 'b':
			val, ok = sx.MakeBoolean(!sx.IsNil(car)), true
		case 'i':
			val, ok = car.(sx.Int64)
		case 'o':
			val, ok = car, true
		case 'p':
			val, ok = sx.GetPair(car)
		case 's':
			val, ok = sx.GetString(car)
		case 'y':
			val, ok = sx.GetSymbol(car)
		default:
			return nil, fmt.Errorf("unknown spec '%c'", spec[i])
		}
		if !ok {
			return nil, fmt.Errorf("does not match spec '%v': %v", spec[i], car)
		}
		result = append(result, val)
		next, isNextPair := sx.GetPair(node.Cdr())
		if !isNextPair {
			return nil, sx.ErrImproper{Pair: pair}
		}
		node = next
	}
	if i < len(spec) {
		return nil, ErrElementsMissing
	}
	return result, nil
}

var ErrElementsMissing = errors.New("spec contains more data")
var ErrNoSpec = errors.New("no spec for elements")

// CheckSymbol ensures that the given object is a symbol with the given name.
func CheckSymbol(obj sx.Object, name string) error {
	sym, isSymbol := sx.GetSymbol(obj)
	if !isSymbol {
		return fmt.Errorf("object %v/%T is not a symbol", obj, obj)
	}
	if got := sym.Name(); got != name {
		return fmt.Errorf("symbol %q expected, but got: %q", name, got)
	}
	return nil
}

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

package sexp_test

import (
	"testing"

	"zettelstore.de/client.fossil/sexp"
	"zettelstore.de/sx.fossil"
)

func TestParseObject(t *testing.T) {
	if elems, err := sexp.ParseList(sx.String("a"), "s"); err == nil {
		t.Error("expected an error, but got: ", elems)
	}
	if elems, err := sexp.ParseList(sx.Nil(), ""); err != nil {
		t.Error(err)
	} else if len(elems) != 0 {
		t.Error("Must be empty, but got:", elems)
	}
	if elems, err := sexp.ParseList(sx.Nil(), "b"); err == nil {
		t.Error("expected error, but got: ", elems)
	}

	if elems, err := sexp.ParseList(sx.MakeList(sx.String("a")), "ss"); err == nil {
		t.Error("expected error, but got: ", elems)
	}
	if elems, err := sexp.ParseList(sx.MakeList(sx.String("a")), ""); err == nil {
		t.Error("expected error, but got: ", elems)
	}
	if _, err := sexp.ParseList(sx.MakeList(sx.String("a")), "b"); err != nil {
		t.Error("expected [1], but got error: ", err)
	}
	if elems, err := sexp.ParseList(sx.Cons(sx.Nil(), sx.String("a")), "ps"); err == nil {
		t.Error("expected error, but got: ", elems)
	}

	if elems, err := sexp.ParseList(sx.MakeList(sx.String("a")), "s"); err != nil {
		t.Error(err)
	} else if len(elems) != 1 {
		t.Error("length == 1, but got: ", elems)
	} else {
		_ = elems[0].(sx.String)
	}

}

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

package sexpr

import "codeberg.org/t73fde/sxpf"

// Various constants for Zettel data. Some of them are technically variables.

const (
	// Symbols for Metanodes
	NameSymBlock  = "BLOCK"
	NameSymInline = "INLINE"
	NameSymList   = "LIST"
	NameSymMeta   = "META"
	NameSymQuote  = "quote"

	// Symbols for Zettel node types.
	NameSymBLOB            = "BLOB"
	NameSymCell            = "CELL"
	NameSymCellCenter      = "CELL-CENTER"
	NameSymCellLeft        = "CELL-LEFT"
	NameSymCellRight       = "CELL-RIGHT"
	NameSymCite            = "CITE"
	NameSymDescription     = "DESCRIPTION"
	NameSymEmbed           = "EMBED"
	NameSymEmbedBLOB       = "EMBED-BLOB"
	NameSymEndnote         = "ENDNOTE"
	NameSymFormatEmph      = "FORMAT-EMPH"
	NameSymFormatDelete    = "FORMAT-DELETE"
	NameSymFormatInsert    = "FORMAT-INSERT"
	NameSymFormatQuote     = "FORMAT-QUOTE"
	NameSymFormatSpan      = "FORMAT-SPAN"
	NameSymFormatSub       = "FORMAT-SUB"
	NameSymFormatSuper     = "FORMAT-SUPER"
	NameSymFormatStrong    = "FORMAT-STRONG"
	NameSymHard            = "HARD"
	NameSymHeading         = "HEADING"
	NameSymLinkInvalid     = "LINK-INVALID"
	NameSymLinkZettel      = "LINK-ZETTEL"
	NameSymLinkSelf        = "LINK-SELF"
	NameSymLinkFound       = "LINK-FOUND"
	NameSymLinkBroken      = "LINK-BROKEN"
	NameSymLinkHosted      = "LINK-HOSTED"
	NameSymLinkBased       = "LINK-BASED"
	NameSymLinkQuery       = "LINK-QUERY"
	NameSymLinkExternal    = "LINK-EXTERNAL"
	NameSymListOrdered     = "ORDERED"
	NameSymListUnordered   = "UNORDERED"
	NameSymListQuote       = "QUOTATION"
	NameSymLiteralProg     = "LITERAL-CODE"
	NameSymLiteralComment  = "LITERAL-COMMENT"
	NameSymLiteralHTML     = "LITERAL-HTML"
	NameSymLiteralInput    = "LITERAL-INPUT"
	NameSymLiteralMath     = "LITERAL-MATH"
	NameSymLiteralOutput   = "LITERAL-OUTPUT"
	NameSymLiteralZettel   = "LITERAL-ZETTEL"
	NameSymMark            = "MARK"
	NameSymPara            = "PARA"
	NameSymRegionBlock     = "REGION-BLOCK"
	NameSymRegionQuote     = "REGION-QUOTE"
	NameSymRegionVerse     = "REGION-VERSE"
	NameSymSoft            = "SOFT"
	NameSymSpace           = "SPACE"
	NameSymTable           = "TABLE"
	NameSymText            = "TEXT"
	NameSymThematic        = "THEMATIC"
	NameSymTransclude      = "TRANSCLUDE"
	NameSymUnknown         = "UNKNOWN-NODE"
	NameSymVerbatimComment = "VERBATIM-COMMENT"
	NameSymVerbatimEval    = "VERBATIM-EVAL"
	NameSymVerbatimHTML    = "VERBATIM-HTML"
	NameSymVerbatimMath    = "VERBATIM-MATH"
	NameSymVerbatimProg    = "VERBATIM-CODE"
	NameSymVerbatimZettel  = "VERBATIM-ZETTEL"

	// Constant symbols for reference states.
	NameSymRefStateInvalid  = "INVALID"
	NameSymRefStateZettel   = "ZETTEL"
	NameSymRefStateSelf     = "SELF"
	NameSymRefStateFound    = "FOUND"
	NameSymRefStateBroken   = "BROKEN"
	NameSymRefStateHosted   = "HOSTED"
	NameSymRefStateBased    = "BASED"
	NameSymRefStateQuery    = "QUERY"
	NameSymRefStateExternal = "EXTERNAL"

	// Symbols for metadata types.
	NameSymTypeCredential   = "CREDENTIAL"
	NameSymTypeEmpty        = "EMPTY-STRING"
	NameSymTypeID           = "ZID"
	NameSymTypeIDSet        = "ZID-SET"
	NameSymTypeNumber       = "NUMBER"
	NameSymTypeString       = "STRING"
	NameSymTypeTagSet       = "TAG-SET"
	NameSymTypeTimestamp    = "TIMESTAMP"
	NameSymTypeURL          = "URL"
	NameSymTypeWord         = "WORD"
	NameSymTypeWordSet      = "WORD-SET"
	NameSymTypeZettelmarkup = "ZETTELMARKUP"
)

// ZettelSymbols collect all symbols needed to represent zettel data.
type ZettelSymbols struct {
	// Symbols for Metanodes
	SymBlock  *sxpf.Symbol
	SymInline *sxpf.Symbol
	SymList   *sxpf.Symbol
	SymMeta   *sxpf.Symbol
	SymQuote  *sxpf.Symbol

	// Symbols for Zettel node types.
	SymBLOB            *sxpf.Symbol
	SymCell            *sxpf.Symbol
	SymCellCenter      *sxpf.Symbol
	SymCellLeft        *sxpf.Symbol
	SymCellRight       *sxpf.Symbol
	SymCite            *sxpf.Symbol
	SymDescription     *sxpf.Symbol
	SymEmbed           *sxpf.Symbol
	SymEmbedBLOB       *sxpf.Symbol
	SymEndnote         *sxpf.Symbol
	SymFormatEmph      *sxpf.Symbol
	SymFormatDelete    *sxpf.Symbol
	SymFormatInsert    *sxpf.Symbol
	SymFormatQuote     *sxpf.Symbol
	SymFormatSpan      *sxpf.Symbol
	SymFormatSub       *sxpf.Symbol
	SymFormatSuper     *sxpf.Symbol
	SymFormatStrong    *sxpf.Symbol
	SymHard            *sxpf.Symbol
	SymHeading         *sxpf.Symbol
	SymLinkInvalid     *sxpf.Symbol
	SymLinkZettel      *sxpf.Symbol
	SymLinkSelf        *sxpf.Symbol
	SymLinkFound       *sxpf.Symbol
	SymLinkBroken      *sxpf.Symbol
	SymLinkHosted      *sxpf.Symbol
	SymLinkBased       *sxpf.Symbol
	SymLinkQuery       *sxpf.Symbol
	SymLinkExternal    *sxpf.Symbol
	SymListOrdered     *sxpf.Symbol
	SymListUnordered   *sxpf.Symbol
	SymListQuote       *sxpf.Symbol
	SymLiteralProg     *sxpf.Symbol
	SymLiteralComment  *sxpf.Symbol
	SymLiteralHTML     *sxpf.Symbol
	SymLiteralInput    *sxpf.Symbol
	SymLiteralMath     *sxpf.Symbol
	SymLiteralOutput   *sxpf.Symbol
	SymLiteralZettel   *sxpf.Symbol
	SymMark            *sxpf.Symbol
	SymPara            *sxpf.Symbol
	SymRegionBlock     *sxpf.Symbol
	SymRegionQuote     *sxpf.Symbol
	SymRegionVerse     *sxpf.Symbol
	SymSoft            *sxpf.Symbol
	SymSpace           *sxpf.Symbol
	SymTable           *sxpf.Symbol
	SymText            *sxpf.Symbol
	SymThematic        *sxpf.Symbol
	SymTransclude      *sxpf.Symbol
	SymUnknown         *sxpf.Symbol
	SymVerbatimComment *sxpf.Symbol
	SymVerbatimEval    *sxpf.Symbol
	SymVerbatimHTML    *sxpf.Symbol
	SymVerbatimMath    *sxpf.Symbol
	SymVerbatimProg    *sxpf.Symbol
	SymVerbatimZettel  *sxpf.Symbol

	// Constant symbols for reference states.

	SymRefStateInvalid  *sxpf.Symbol
	SymRefStateZettel   *sxpf.Symbol
	SymRefStateSelf     *sxpf.Symbol
	SymRefStateFound    *sxpf.Symbol
	SymRefStateBroken   *sxpf.Symbol
	SymRefStateHosted   *sxpf.Symbol
	SymRefStateBased    *sxpf.Symbol
	SymRefStateQuery    *sxpf.Symbol
	SymRefStateExternal *sxpf.Symbol

	// Symbols for metadata types

	SymTypeCredential   *sxpf.Symbol
	SymTypeEmpty        *sxpf.Symbol
	SymTypeID           *sxpf.Symbol
	SymTypeIDSet        *sxpf.Symbol
	SymTypeNumber       *sxpf.Symbol
	SymTypeString       *sxpf.Symbol
	SymTypeTagSet       *sxpf.Symbol
	SymTypeTimestamp    *sxpf.Symbol
	SymTypeURL          *sxpf.Symbol
	SymTypeWord         *sxpf.Symbol
	SymTypeWordSet      *sxpf.Symbol
	SymTypeZettelmarkup *sxpf.Symbol
}

func (zs *ZettelSymbols) InitializeZettelSymbols(sf sxpf.SymbolFactory) {
	// Symbols for Metanodes
	zs.SymBlock = sf.MustMake(NameSymBlock)
	zs.SymInline = sf.MustMake(NameSymInline)
	zs.SymList = sf.MustMake(NameSymList)
	zs.SymMeta = sf.MustMake(NameSymMeta)
	zs.SymQuote = sf.MustMake(NameSymQuote)

	// Symbols for Zettel node types.
	zs.SymBLOB = sf.MustMake(NameSymBLOB)
	zs.SymCell = sf.MustMake(NameSymCell)
	zs.SymCellCenter = sf.MustMake(NameSymCellCenter)
	zs.SymCellLeft = sf.MustMake(NameSymCellLeft)
	zs.SymCellRight = sf.MustMake(NameSymCellRight)
	zs.SymCite = sf.MustMake(NameSymCite)
	zs.SymDescription = sf.MustMake(NameSymDescription)
	zs.SymEmbed = sf.MustMake(NameSymEmbed)
	zs.SymEmbedBLOB = sf.MustMake(NameSymEmbedBLOB)
	zs.SymEndnote = sf.MustMake(NameSymEndnote)
	zs.SymFormatEmph = sf.MustMake(NameSymFormatEmph)
	zs.SymFormatDelete = sf.MustMake(NameSymFormatDelete)
	zs.SymFormatInsert = sf.MustMake(NameSymFormatInsert)
	zs.SymFormatQuote = sf.MustMake(NameSymFormatQuote)
	zs.SymFormatSpan = sf.MustMake(NameSymFormatSpan)
	zs.SymFormatSub = sf.MustMake(NameSymFormatSub)
	zs.SymFormatSuper = sf.MustMake(NameSymFormatSuper)
	zs.SymFormatStrong = sf.MustMake(NameSymFormatStrong)
	zs.SymHard = sf.MustMake(NameSymHard)
	zs.SymHeading = sf.MustMake(NameSymHeading)
	zs.SymLinkInvalid = sf.MustMake(NameSymLinkInvalid)
	zs.SymLinkZettel = sf.MustMake(NameSymLinkZettel)
	zs.SymLinkSelf = sf.MustMake(NameSymLinkSelf)
	zs.SymLinkFound = sf.MustMake(NameSymLinkFound)
	zs.SymLinkBroken = sf.MustMake(NameSymLinkBroken)
	zs.SymLinkHosted = sf.MustMake(NameSymLinkHosted)
	zs.SymLinkBased = sf.MustMake(NameSymLinkBased)
	zs.SymLinkQuery = sf.MustMake(NameSymLinkQuery)
	zs.SymLinkExternal = sf.MustMake(NameSymLinkExternal)
	zs.SymListOrdered = sf.MustMake(NameSymListOrdered)
	zs.SymListUnordered = sf.MustMake(NameSymListUnordered)
	zs.SymListQuote = sf.MustMake(NameSymListQuote)
	zs.SymLiteralProg = sf.MustMake(NameSymLiteralProg)
	zs.SymLiteralComment = sf.MustMake(NameSymLiteralComment)
	zs.SymLiteralHTML = sf.MustMake(NameSymLiteralHTML)
	zs.SymLiteralInput = sf.MustMake(NameSymLiteralInput)
	zs.SymLiteralMath = sf.MustMake(NameSymLiteralMath)
	zs.SymLiteralOutput = sf.MustMake(NameSymLiteralOutput)
	zs.SymLiteralZettel = sf.MustMake(NameSymLiteralZettel)
	zs.SymMark = sf.MustMake(NameSymMark)
	zs.SymPara = sf.MustMake(NameSymPara)
	zs.SymRegionBlock = sf.MustMake(NameSymRegionBlock)
	zs.SymRegionQuote = sf.MustMake(NameSymRegionQuote)
	zs.SymRegionVerse = sf.MustMake(NameSymRegionVerse)
	zs.SymSoft = sf.MustMake(NameSymSoft)
	zs.SymSpace = sf.MustMake(NameSymSpace)
	zs.SymTable = sf.MustMake(NameSymTable)
	zs.SymText = sf.MustMake(NameSymText)
	zs.SymThematic = sf.MustMake(NameSymThematic)
	zs.SymTransclude = sf.MustMake(NameSymTransclude)
	zs.SymUnknown = sf.MustMake(NameSymUnknown)
	zs.SymVerbatimComment = sf.MustMake(NameSymVerbatimComment)
	zs.SymVerbatimEval = sf.MustMake(NameSymVerbatimEval)
	zs.SymVerbatimHTML = sf.MustMake(NameSymVerbatimHTML)
	zs.SymVerbatimMath = sf.MustMake(NameSymVerbatimMath)
	zs.SymVerbatimProg = sf.MustMake(NameSymVerbatimProg)
	zs.SymVerbatimZettel = sf.MustMake(NameSymVerbatimZettel)

	// Constant symbols for reference states.
	zs.SymRefStateInvalid = sf.MustMake(NameSymRefStateInvalid)
	zs.SymRefStateZettel = sf.MustMake(NameSymRefStateZettel)
	zs.SymRefStateSelf = sf.MustMake(NameSymRefStateSelf)
	zs.SymRefStateFound = sf.MustMake(NameSymRefStateFound)
	zs.SymRefStateBroken = sf.MustMake(NameSymRefStateBroken)
	zs.SymRefStateHosted = sf.MustMake(NameSymRefStateHosted)
	zs.SymRefStateBased = sf.MustMake(NameSymRefStateBased)
	zs.SymRefStateQuery = sf.MustMake(NameSymRefStateQuery)
	zs.SymRefStateExternal = sf.MustMake(NameSymRefStateExternal)

	// Symbols for metadata types.
	zs.SymTypeCredential = sf.MustMake(NameSymTypeCredential)
	zs.SymTypeEmpty = sf.MustMake(NameSymTypeEmpty)
	zs.SymTypeID = sf.MustMake(NameSymTypeID)
	zs.SymTypeIDSet = sf.MustMake(NameSymTypeIDSet)
	zs.SymTypeNumber = sf.MustMake(NameSymTypeNumber)
	zs.SymTypeString = sf.MustMake(NameSymTypeString)
	zs.SymTypeTagSet = sf.MustMake(NameSymTypeTagSet)
	zs.SymTypeTimestamp = sf.MustMake(NameSymTypeTimestamp)
	zs.SymTypeURL = sf.MustMake(NameSymTypeURL)
	zs.SymTypeWord = sf.MustMake(NameSymTypeWord)
	zs.SymTypeWordSet = sf.MustMake(NameSymTypeWordSet)
	zs.SymTypeZettelmarkup = sf.MustMake(NameSymTypeZettelmarkup)
}

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

package sexpr_test

import (
	"testing"

	"codeberg.org/t73fde/sxpf"
	"zettelstore.de/c/sexpr"
)

func BenchmarkInitializeZettelSymbols(b *testing.B) {
	sf := sxpf.MakeMappedFactory()
	for i := 0; i < b.N; i++ {
		var zs sexpr.ZettelSymbols
		zs.InitializeZettelSymbols(sf)
	}
}

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

package sexpr

import (
	"codeberg.org/t73fde/sxpf"
	"zettelstore.de/c/attrs"
)

// GetAttributes traverses a s-expression list and returns an attribute structure.
func GetAttributes(seq *sxpf.List) (result attrs.Attributes) {
	for elem := seq; elem != nil; elem = elem.Tail() {
		p, ok := elem.Car().(*sxpf.List)
		if !ok || p == nil {
			continue
		}
		key := p.Car()
		if !sxpf.IsAtom(key) {
			continue
		}
		val := p.Cdr()
		if tail, ok2 := val.(*sxpf.List); ok2 {
			val = tail.Car()
		}
		if !sxpf.IsAtom(val) {
			continue
		}
		result = result.Set(key.String(), val.String())
	}
	return result
}

// GetMetaContent returns the metadata and the content of a sexpr encoded zettel.
func GetMetaContent(zettel sxpf.Object) (Meta, *sxpf.List) {
	if pair, ok := zettel.(*sxpf.List); ok {
		m := pair.Car()
		if s := pair.Tail(); s != nil {
			if content, ok2 := s.Car().(*sxpf.List); ok2 {
				return MakeMeta(m), content
			}
		}
		return MakeMeta(m), nil
	}
	return nil, nil
}

type Meta map[string]MetaValue
type MetaValue struct {
	Type  string
	Key   string
	Value sxpf.Object
}

func MakeMeta(val sxpf.Object) Meta {
	if result := doMakeMeta(val); len(result) > 0 {
		return result
	}
	return nil
}
func doMakeMeta(val sxpf.Object) Meta {
	result := make(map[string]MetaValue)
	for {
		if sxpf.IsNil(val) {
			return result
		}
		lst, ok := val.(*sxpf.List)
		if !ok {
			return result
		}
		if mv, ok2 := makeMetaValue(lst); ok2 {
			result[mv.Key] = mv
		}
		val = lst.Cdr()
	}
}
func makeMetaValue(pair *sxpf.List) (MetaValue, bool) {
	var result MetaValue
	typePair, ok := pair.Car().(*sxpf.List)
	if !ok {
		return result, false
	}
	typeVal, ok := typePair.Car().(*sxpf.Symbol)
	if !ok {
		return result, false
	}
	keyPair, ok := typePair.Cdr().(*sxpf.List)
	if !ok {
		return result, false
	}
	keyStr, ok := keyPair.Car().(sxpf.String)
	if !ok {
		return result, false
	}
	valPair, ok := keyPair.Cdr().(*sxpf.List)
	if !ok {
		return result, false
	}
	result.Type = typeVal.CanonicalName()
	result.Key = keyStr.String()
	result.Value = valPair.Car()
	return result, true
}

func (m Meta) GetString(key string) string {
	if v, found := m[key]; found {
		return v.Value.String()
	}
	return ""
}

func (m Meta) GetList(key string) *sxpf.List {
	if mv, found := m[key]; found {
		if seq, ok := mv.Value.(*sxpf.List); ok {
			return seq
		}
	}
	return nil
}

import (
	"fmt"
	"net/url"
	"strconv"
	"strings"

	"zettelstore.de/client.fossil/api"
	"zettelstore.de/client.fossil/attrs"
	"zettelstore.de/client.fossil/sz"
	"zettelstore.de/client.fossil/text"
	"zettelstore.de/sx.fossil"
	"zettelstore.de/sx.fossil/sxhtml"
	"codeberg.org/t73fde/sxhtml"
	"codeberg.org/t73fde/sxpf"
	"codeberg.org/t73fde/sxpf/builtins/quote"
	"codeberg.org/t73fde/sxpf/eval"
	"zettelstore.de/c/api"
	"zettelstore.de/c/attrs"
	"zettelstore.de/c/sexpr"
	"zettelstore.de/c/text"
)

// Evaluator will transform a s-expression that encodes the zettel AST into an s-expression
// Transformer will transform a s-expression that encodes the zettel AST into an s-expression
// that represents HTML.
type Evaluator struct {
	sf            sx.SymbolFactory
type Transformer struct {
	sf            sxpf.SymbolFactory
	rebinder      RebindProc
	headingOffset int64
	unique        string
	endnotes      []endnoteInfo
	noLinks       bool // true iff output must not include links

	symAttr     *sx.Symbol
	symAttr       *sxpf.Symbol
	symList     *sx.Symbol
	symNoEscape *sx.Symbol
	symClass    *sx.Symbol
	symMeta     *sx.Symbol
	symClass      *sxpf.Symbol
	symMeta       *sxpf.Symbol
	symP        *sx.Symbol
	symLI       *sx.Symbol
	symA        *sx.Symbol
	symA          *sxpf.Symbol
	symHREF     *sx.Symbol
	symSpan     *sx.Symbol

	fns     map[string]EvalFn
	minArgs map[string]int
	symSpan       *sxpf.Symbol
}

type endnoteInfo struct {
	noteAST *sxpf.List // Endnote as AST
	noteHx  *sxpf.List // Endnote as SxHTML
	attrs   *sxpf.List // attrs a-list
}

// NewEvaluator creates a new Evaluator object.
func NewEvaluator(headingOffset int, sf sx.SymbolFactory) *Evaluator {
// NewTransformer creates a new transformer object.
func NewTransformer(headingOffset int, sf sxpf.SymbolFactory) *Transformer {
	if sf == nil {
		sf = sx.MakeMappedFactory(128)
		sf = sxpf.MakeMappedFactory()
	}
	ev := &Evaluator{
	return &Transformer{
		sf:            sf,
		rebinder:      nil,
		headingOffset: int64(headingOffset),
		symAttr:       sf.MustMake(sxhtml.NameSymAttr),
		symList:       sf.MustMake(sxhtml.NameSymList),
		symNoEscape:   sf.MustMake(sxhtml.NameSymNoEscape),
		symClass:      sf.MustMake("class"),
		symMeta:       sf.MustMake("meta"),
		symP:          sf.MustMake("p"),
		symLI:         sf.MustMake("li"),
		symA:          sf.MustMake("a"),
		symHREF:       sf.MustMake("href"),
		symSpan:       sf.MustMake("span"),

	}
		fns:     make(map[string]EvalFn, 128),
		minArgs: make(map[string]int, 128),
	}
}
	ev.bindCommon()
	ev.bindMetadata()
	ev.bindBlocks()
	ev.bindInlines()
	return ev
}

// SymbolFactory returns the symbol factory to create HTML symbols.
func (tr *Transformer) SymbolFactory() sxpf.SymbolFactory { return tr.sf }

// SetUnique sets a prefix to make several HTML ids unique.
func (tr *Evaluator) SetUnique(s string) { tr.unique = s }
func (tr *Transformer) SetUnique(s string) { tr.unique = s }

// SymbolFactory returns the symbol factory of this evaluator.
func (ev *Evaluator) SymbolFactory() sx.SymbolFactory { return ev.sf }

// IsValidName returns true, if name is a valid symbol name.
func (tr *Evaluator) IsValidName(s string) bool { return tr.sf.IsValidName(s) }
func (tr *Transformer) IsValidName(s string) bool { return tr.sf.IsValidName(s) }

// Make a new HTML symbol.
func (tr *Evaluator) Make(s string) *sx.Symbol { return tr.sf.MustMake(s) }
func (tr *Transformer) Make(s string) *sxpf.Symbol { return tr.sf.MustMake(s) }

// RebindProc is a procedure which is called every time before a tranformation takes place.
type RebindProc func(*TransformEnv)

// SetRebinder sets the rebinder procedure.
func (tr *Transformer) SetRebinder(rb RebindProc) { tr.rebinder = rb }

// EvaluateAttrbute transforms the given attributes into a HTML s-expression.
func (tr *Evaluator) EvaluateAttrbute(a attrs.Attributes) *sx.Pair {
// TransformAttrbute transforms the given attributes into a HTML s-expression.
func (tr *Transformer) TransformAttrbute(a attrs.Attributes) *sxpf.List {
	if len(a) == 0 {
		return nil
		return sxpf.Nil()
	}
	plist := sx.Nil()
	plist := sxpf.Nil()
	keys := a.Keys()
	for i := len(keys) - 1; i >= 0; i-- {
		key := keys[i]
		if key != attrs.DefaultAttribute && tr.IsValidName(key) {
			plist = plist.Cons(sx.Cons(tr.Make(key), sx.String(a[key])))
			plist = plist.Cons(sxpf.Cons(tr.Make(key), sxpf.MakeString(a[key])))
		}
	}
	if plist == nil {
		return nil
		return sxpf.Nil()
	}
	return plist.Cons(tr.symAttr)
}

// TransformMeta creates a HTML meta s-expression
func (tr *Transformer) TransformMeta(a attrs.Attributes) *sxpf.List {
	return sxpf.Nil().Cons(tr.TransformAttrbute(a)).Cons(tr.symMeta)
}

// Evaluate a metadata s-expression into a list of HTML s-expressions.
func (ev *Evaluator) Evaluate(lst *sx.Pair, env *Environment) (*sx.Pair, error) {
	result := ev.eval(lst, env)
	if err := env.err; err != nil {
		return nil, err
// Transform an AST s-expression into a list of HTML s-expressions.
func (tr *Transformer) Transform(lst *sxpf.List) (*sxpf.List, error) {
	astSF := sxpf.FindSymbolFactory(lst)
	if astSF != nil {
		if astSF == tr.sf {
			panic("Invalid AST SymbolFactory")
		}
	} else {
		astSF = sxpf.MakeMappedFactory()
	}
	astEnv := sxpf.MakeRootEnvironment()
	engine := eval.MakeEngine(astSF, astEnv, eval.MakeDefaultParser(), eval.MakeSimpleExecutor())
	quote.InstallQuote(engine, sexpr.NameSymQuote, nil, 0)
	te := TransformEnv{
		tr:      tr,
		astSF:   astSF,
		astEnv:  astEnv,
		err:     nil,
		textEnc: text.NewEncoder(astSF),
	}
	te.initialize()
	if rb := tr.rebinder; rb != nil {
		rb(&te)
	}
	pair, isPair := sx.GetPair(result)
	if !isPair {
		return nil, fmt.Errorf("evaluation does not result in a pair, but %T/%v", result, result)

	val, err := engine.Eval(te.astEnv, lst)
	if err != nil {
		return sxpf.Nil(), err
	}
	res, ok := val.(*sxpf.List)
	if !ok {
		panic("Result is not a list")

	for i := 0; i < len(env.endnotes); i++ {
	}
	for i := 0; i < len(tr.endnotes); i++ {
		// May extend tr.endnotes

		val, err = engine.Eval(te.astEnv, tr.endnotes[i].noteAST)
		if env.endnotes[i].noteHx != nil {
			continue
		}

		objHx := ev.eval(env.endnotes[i].noteAST, env)
		if env.err != nil {
			break
		if err != nil {
			return res, err
		}
		noteHx, isHx := sx.GetPair(objHx)
		if !isHx {
			return nil, fmt.Errorf("endnote evaluation does not result in pair, but %T/%v", objHx, objHx)
		en, ok2 := val.(*sxpf.List)
		if !ok2 {
			panic("Endnote is not a list")
		}
		env.endnotes[i].noteHx = noteHx
		tr.endnotes[i].noteHx = en
	}
	return res, err

	return pair, nil
}

// Endnotes returns a SHTML object with all collected endnotes.
func (ev *Evaluator) Endnotes(env *Environment) *sx.Pair {
	if env.err != nil || len(env.endnotes) == 0 {
func (tr *Transformer) Endnotes() *sxpf.List {
	if len(tr.endnotes) == 0 {
		return nil
	}

	result := sxpf.Nil().Cons(tr.Make("ol"))
	result := sx.Nil().Cons(ev.Make("ol"))
	symValue, symId, symRole := ev.Make("value"), ev.Make("id"), ev.Make("role")

	currResult := result.AppendBang(sxpf.Nil().Cons(sxpf.Cons(tr.symClass, sxpf.MakeString("zs-endnotes"))).Cons(tr.symAttr))
	currResult := result.AppendBang(sx.Nil().Cons(sx.Cons(ev.symClass, sx.String("zs-endnotes"))).Cons(ev.symAttr))
	for i, fni := range env.endnotes {
	for i, fni := range tr.endnotes {
		noteNum := strconv.Itoa(i + 1)
		noteID := tr.unique + noteNum

		attrs := fni.attrs.Cons(sx.Cons(ev.symClass, sx.String("zs-endnote"))).
			Cons(sx.Cons(symValue, sx.String(noteNum))).
			Cons(sx.Cons(symId, sx.String("fn:"+fni.noteID))).
			Cons(sx.Cons(symRole, sx.String("doc-endnote"))).
			Cons(ev.symAttr)
		attrs := fni.attrs.Cons(sxpf.Cons(tr.symClass, sxpf.MakeString("zs-endnote"))).
			Cons(sxpf.Cons(tr.Make("value"), sxpf.MakeString(noteNum))).
			Cons(sxpf.Cons(tr.Make("id"), sxpf.MakeString("fn:"+noteID))).
			Cons(sxpf.Cons(tr.Make("role"), sxpf.MakeString("doc-endnote"))).
			Cons(tr.symAttr)

		backref := sx.Nil().Cons(sx.String("\u21a9\ufe0e")).
			Cons(sx.Nil().
				Cons(sx.Cons(ev.symClass, sx.String("zs-endnote-backref"))).
				Cons(sx.Cons(ev.symHREF, sx.String("#fnref:"+fni.noteID))).
				Cons(sx.Cons(symRole, sx.String("doc-backlink"))).
				Cons(ev.symAttr)).
			Cons(ev.symA)
		backref := sxpf.Nil().Cons(sxpf.MakeString("\u21a9\ufe0e")).
			Cons(sxpf.Nil().
				Cons(sxpf.Cons(tr.symClass, sxpf.MakeString("zs-endnote-backref"))).
				Cons(sxpf.Cons(tr.Make("href"), sxpf.MakeString("#fnref:"+noteID))).
				Cons(sxpf.Cons(tr.Make("role"), sxpf.MakeString("doc-backlink"))).
				Cons(tr.symAttr)).
			Cons(tr.symA)

		li := sx.Nil().Cons(ev.symLI)
		li := sxpf.Nil().Cons(tr.Make("li"))
		li.AppendBang(attrs).
			ExtendBang(fni.noteHx).
			AppendBang(sx.String(" ")).AppendBang(backref)
			AppendBang(sxpf.MakeString(" ")).AppendBang(backref)
		currResult = currResult.AppendBang(li)
	}
	tr.endnotes = nil
	return result
}

// Environment where sz objects are evaluated to shtml objects
type Environment struct {
	err          error
// TransformEnv is the environment where the actual transformation takes places.
type TransformEnv struct {
	tr          *Transformer
	astSF       sxpf.SymbolFactory
	astEnv      sxpf.Environment
	err         error
	langStack    []string
	endnotes     []endnoteInfo
	textEnc     *text.Encoder
	quoteNesting uint
}
type endnoteInfo struct {
	symNoEscape *sxpf.Symbol
	noteID  string    // link id
	noteAST sx.Object // Endnote as AST
	attrs   *sx.Pair  // attrs a-list
	symAttr     *sxpf.Symbol
	noteHx  *sx.Pair  // Endnote as SxHTML
}

	symMeta     *sxpf.Symbol
// MakeEnvironment builds a new evaluation environment.
func MakeEnvironment(lang string) Environment {
	langStack := make([]string, 1, 16)
	langStack[0] = lang
	return Environment{
		err:          nil,
		langStack:    langStack,
		endnotes:     nil,
	symA        *sxpf.Symbol
	symSpan     *sxpf.Symbol
	symP        *sxpf.Symbol
		quoteNesting: 0,
	}
}

}

func (te *TransformEnv) initialize() {
// GetError returns the last error found.
func (env *Environment) GetError() error { return env.err }

	te.symNoEscape = te.Make(sxhtml.NameSymNoEscape)
// Reset the environment.
func (env *Environment) Reset() {
	env.langStack = env.langStack[0:1]
	env.endnotes = nil
	env.quoteNesting = 0
	te.symAttr = te.tr.symAttr
	te.symMeta = te.tr.symMeta
	te.symA = te.tr.symA
}

	te.symSpan = te.tr.symSpan
// PushAttribute adds the current attributes to the environment.
func (env *Environment) pushAttributes(a attrs.Attributes) {
	if value, ok := a.Get("lang"); ok {
		env.langStack = append(env.langStack, value)
	} else {
		env.langStack = append(env.langStack, env.getLanguage())
	}
}
	te.symP = te.Make("p")

// popAttributes removes the current attributes from the envrionment
func (env *Environment) popAttributes() {
	env.langStack = env.langStack[0 : len(env.langStack)-1]
}

	te.bind(sexpr.NameSymList, 0, listArgs)
// getLanguage returns the current language
func (env *Environment) getLanguage() string {
	return env.langStack[len(env.langStack)-1]
}

	te.bindMetadata()
// EvalFn is a function to be called for evaluation.
type EvalFn func([]sx.Object, *Environment) sx.Object

	te.bindBlocks()
func (ev *Evaluator) bind(name string, minArgs int, fn EvalFn) {
	ev.fns[name] = fn
	if minArgs > 0 {
	te.bindInlines()
		ev.minArgs[name] = minArgs
	}
}

}

func listArgs(args *sxpf.List) sxpf.Object { return args }
// ResolveBinding returns the function bound to the given name.
func (ev *Evaluator) ResolveBinding(name string) EvalFn {
	if fn, found := ev.fns[name]; found {
		return fn
	}

	return nil
}

func (te *TransformEnv) bindMetadata() {
// Rebind overwrites a binding, but leaves the minimum number of arguments intact.
func (ev *Evaluator) Rebind(name string, fn EvalFn) {
	if _, found := ev.fns[name]; !found {
		panic(name)
	te.bind(sexpr.NameSymMeta, 0, listArgs)
	te.bind(sexpr.NameSymTypeZettelmarkup, 2, func(args *sxpf.List) sxpf.Object {
		a := make(attrs.Attributes, 2).
			Set("name", te.getString(args).String()).
	}
	ev.fns[name] = fn
}

			Set("content", te.textEnc.Encode(te.getList(args.Tail())))
func (ev *Evaluator) bindCommon() {
	ev.bind(sx.ListName, 0, ev.evalList)
	ev.bind("quote", 1, func(args []sx.Object, _ *Environment) sx.Object { return args[0] })
}
		return te.transformMeta(a)
	})

func (ev *Evaluator) bindMetadata() {
	ev.bind(sz.NameSymMeta, 0, ev.evalList)
	evalMetaString := func(args []sx.Object, env *Environment) sx.Object {
	metaString := func(args *sxpf.List) sxpf.Object {
		a := make(attrs.Attributes, 2).
			Set("name", ev.getSymbol(ev.eval(args[0], env), env).Name()).
			Set("content", getString(args[1], env).String())
		return ev.EvaluateMeta(a)
			Set("name", te.getString(args).String()).
			Set("content", te.getString(args.Tail()).String())
		return te.transformMeta(a)
	}
	ev.bind(sz.NameSymTypeCredential, 2, evalMetaString)
	ev.bind(sz.NameSymTypeEmpty, 2, evalMetaString)
	ev.bind(sz.NameSymTypeID, 2, evalMetaString)
	ev.bind(sz.NameSymTypeNumber, 2, evalMetaString)
	ev.bind(sz.NameSymTypeString, 2, evalMetaString)
	ev.bind(sz.NameSymTypeTimestamp, 2, evalMetaString)
	ev.bind(sz.NameSymTypeURL, 2, evalMetaString)
	ev.bind(sz.NameSymTypeWord, 2, evalMetaString)
	te.bind(sexpr.NameSymTypeCredential, 2, metaString)
	te.bind(sexpr.NameSymTypeEmpty, 2, metaString)
	te.bind(sexpr.NameSymTypeID, 2, metaString)
	te.bind(sexpr.NameSymTypeNumber, 2, metaString)
	te.bind(sexpr.NameSymTypeString, 2, metaString)
	te.bind(sexpr.NameSymTypeTimestamp, 2, metaString)
	te.bind(sexpr.NameSymTypeURL, 2, metaString)
	te.bind(sexpr.NameSymTypeWord, 2, metaString)

	evalMetaSet := func(args []sx.Object, env *Environment) sx.Object {
	metaSet := func(args *sxpf.List) sxpf.Object {
		var sb strings.Builder
		lst := ev.eval(args[1], env)
		for elem := getList(lst, env); elem != nil; elem = elem.Tail() {
		for elem := te.getList(args.Tail()); elem != nil; elem = elem.Tail() {
			sb.WriteByte(' ')
			sb.WriteString(getString(elem.Car(), env).String())
			sb.WriteString(te.getString(elem).String())
		}
		s := sb.String()
		if len(s) > 0 {
			s = s[1:]
		}
		a := make(attrs.Attributes, 2).
			Set("name", ev.getSymbol(ev.eval(args[0], env), env).Name()).
			Set("name", te.getString(args).String()).
			Set("content", s)
		return ev.EvaluateMeta(a)
		return te.transformMeta(a)
	}
	ev.bind(sz.NameSymTypeIDSet, 2, evalMetaSet)
	ev.bind(sz.NameSymTypeTagSet, 2, evalMetaSet)
	ev.bind(sz.NameSymTypeWordSet, 2, evalMetaSet)
	te.bind(sexpr.NameSymTypeIDSet, 2, metaSet)
	te.bind(sexpr.NameSymTypeTagSet, 2, metaSet)
	te.bind(sexpr.NameSymTypeWordSet, 2, metaSet)
	ev.bind(sz.NameSymTypeZettelmarkup, 2, func(args []sx.Object, env *Environment) sx.Object {
		a := make(attrs.Attributes, 2).
			Set("name", ev.getSymbol(ev.eval(args[0], env), env).String()).
			Set("content", text.EvaluateInlineString(getList(args[1], env)))
		return ev.EvaluateMeta(a)
	})
}

// EvaluateMeta returns HTML meta object for an attribute.
func (ev *Evaluator) EvaluateMeta(a attrs.Attributes) *sx.Pair {
func (te *TransformEnv) bindBlocks() {
	return sx.Nil().Cons(ev.EvaluateAttrbute(a)).Cons(ev.symMeta)
}

	te.bind(sexpr.NameSymBlock, 0, listArgs)
	te.bind(sexpr.NameSymPara, 0, func(args *sxpf.List) sxpf.Object {
		for ; args != nil; args = args.Tail() {
			lst, ok := sxpf.GetList(args.Car())
			if !ok || lst != nil {
				break
			}
		}
func (ev *Evaluator) bindBlocks() {
	ev.bind(sz.NameSymBlock, 0, ev.evalList)
	ev.bind(sz.NameSymPara, 0, func(args []sx.Object, env *Environment) sx.Object {
		return ev.evalSlice(args, env).Cons(ev.symP)
		return args.Cons(te.symP)
	})
	ev.bind(sz.NameSymHeading, 5, func(args []sx.Object, env *Environment) sx.Object {
		nLevel := getInt64(args[0], env)
	te.bind(sexpr.NameSymHeading, 5, func(args *sxpf.List) sxpf.Object {
		nLevel := te.getInt64(args)
		if nLevel <= 0 {
			env.err = fmt.Errorf("%v is a negative level", nLevel)
			return sx.Nil()
			te.err = fmt.Errorf("%v is a negative level", nLevel)
			return sxpf.Nil()
		}
		level := strconv.FormatInt(nLevel+ev.headingOffset, 10)
		level := strconv.FormatInt(nLevel+te.tr.headingOffset, 10)

		a := ev.getAttributes(args[1], env)
		env.pushAttributes(a)
		defer env.popAttributes()
		if fragment := getString(args[3], env).String(); fragment != "" {
			a = a.Set("id", ev.unique+fragment)
		argAttr := args.Tail()
		a := te.getAttributes(argAttr)
		argFragment := argAttr.Tail().Tail()
		if fragment := te.getString(argFragment).String(); fragment != "" {
			a = a.Set("id", te.tr.unique+fragment)
		}

		if result, isPair := sx.GetPair(ev.eval(args[4], env)); isPair && result != nil {
		if result, ok := sxpf.GetList(argFragment.Tail().Car()); ok && result != nil {
			if len(a) > 0 {
				result = result.Cons(ev.EvaluateAttrbute(a))
				result = result.Cons(te.transformAttribute(a))
			}
			return result.Cons(ev.Make("h" + level))
			return result.Cons(te.Make("h" + level))
		}
		return sx.MakeList(ev.Make("h"+level), sx.String("<MISSING TEXT>"))
		return sxpf.MakeList(te.Make("h"+level), sxpf.MakeString("<MISSING TEXT>"))
	})
	ev.bind(sz.NameSymThematic, 0, func(args []sx.Object, env *Environment) sx.Object {
		result := sx.Nil()
		if len(args) > 0 {
			if attrList := getList(ev.eval(args[0], env), env); attrList != nil {
				result = result.Cons(ev.EvaluateAttrbute(sz.GetAttributes(attrList)))
	te.bind(sexpr.NameSymThematic, 0, func(args *sxpf.List) sxpf.Object {
		result := sxpf.Nil()
		if args != nil {
			if attrList := te.getList(args); attrList != nil {
				result = result.Cons(te.transformAttribute(sexpr.GetAttributes(attrList)))
			}
		}
		return result.Cons(ev.Make("hr"))
		return result.Cons(te.Make("hr"))
	})

	ev.bind(sz.NameSymListOrdered, 0, ev.makeListFn("ol"))
	ev.bind(sz.NameSymListUnordered, 0, ev.makeListFn("ul"))
	ev.bind(sz.NameSymDescription, 0, func(args []sx.Object, env *Environment) sx.Object {
		if len(args) == 0 {
			return sx.Nil()
	te.bind(sexpr.NameSymListOrdered, 0, te.makeListFn("ol"))
	te.bind(sexpr.NameSymListUnordered, 0, te.makeListFn("ul"))
	te.bind(sexpr.NameSymDescription, 0, func(args *sxpf.List) sxpf.Object {
		if args == nil {
			return sxpf.Nil()
		}
		items := sx.Nil().Cons(ev.Make("dl"))
		items := sxpf.Nil().Cons(te.Make("dl"))
		curItem := items
		for pos := 0; pos < len(args); pos++ {
			term := getList(ev.eval(args[pos], env), env)
			curItem = curItem.AppendBang(term.Cons(ev.Make("dt")))
		for elem := args; elem != nil; elem = elem.Tail() {
			term := te.getList(elem)
			curItem = curItem.AppendBang(term.Cons(te.Make("dt")))
			pos++
			if pos >= len(args) {
			elem = elem.Tail()
			if elem == nil {
				break
			}
			ddBlock := getList(ev.eval(args[pos], env), env)
			ddBlock := te.getList(elem)
			if ddBlock == nil {
				continue
				break
			}
			for ddlst := ddBlock; ddlst != nil; ddlst = ddlst.Tail() {
				dditem := getList(ddlst.Car(), env)
				curItem = curItem.AppendBang(dditem.Cons(ev.Make("dd")))
				dditem := te.getList(ddlst)
				curItem = curItem.AppendBang(dditem.Cons(te.Make("dd")))
			}
		}
		return items
	})

	ev.bind(sz.NameSymListQuote, 0, func(args []sx.Object, env *Environment) sx.Object {
	te.bind(sexpr.NameSymListQuote, 0, func(args *sxpf.List) sxpf.Object {
		if args == nil {
			return sx.Nil()
			return sxpf.Nil()
		}
		result := sx.Nil().Cons(ev.Make("blockquote"))
		result := sxpf.Nil().Cons(te.Make("blockquote"))
		currResult := result
		for _, elem := range args {
			if quote, isPair := sx.GetPair(ev.eval(elem, env)); isPair {
				currResult = currResult.AppendBang(quote.Cons(ev.symP))
		for elem := args; elem != nil; elem = elem.Tail() {
			if quote, ok := elem.Car().(*sxpf.List); ok {
				currResult = currResult.AppendBang(quote.Cons(te.symP))
			}
		}
		return result
	})

	ev.bind(sz.NameSymTable, 1, func(args []sx.Object, env *Environment) sx.Object {
		thead := sx.Nil()
		if header := getList(ev.eval(args[0], env), env); !sx.IsNil(header) {
			thead = sx.Nil().Cons(ev.evalTableRow(header)).Cons(ev.Make("thead"))
	te.bind(sexpr.NameSymTable, 1, func(args *sxpf.List) sxpf.Object {
		thead := sxpf.Nil()
		if header := te.getList(args); header != nil {
			thead = sxpf.Nil().Cons(te.transformTableRow(header)).Cons(te.Make("thead"))
		}

		tbody := sx.Nil()
		if len(args) > 1 {
			tbody = sx.Nil().Cons(ev.Make("tbody"))
		tbody := sxpf.Nil()
		if argBody := args.Tail(); argBody != nil {
			tbody = sxpf.Nil().Cons(te.Make("tbody"))
			curBody := tbody
			for _, row := range args[1:] {
				curBody = curBody.AppendBang(ev.evalTableRow(getList(ev.eval(row, env), env)))
			for row := argBody; row != nil; row = row.Tail() {
				curBody = curBody.AppendBang(te.transformTableRow(te.getList(row)))
			}
		}

		table := sx.Nil()
		table := sxpf.Nil()
		if tbody != nil {
			table = table.Cons(tbody)
		}
		if thead != nil {
			table = table.Cons(thead)
		}
		if table == nil {
			return sx.Nil()
			return sxpf.Nil()
		}
		return table.Cons(ev.Make("table"))
		return table.Cons(te.Make("table"))
	})
	ev.bind(sz.NameSymCell, 0, ev.makeCellFn(""))
	ev.bind(sz.NameSymCellCenter, 0, ev.makeCellFn("center"))
	ev.bind(sz.NameSymCellLeft, 0, ev.makeCellFn("left"))
	ev.bind(sz.NameSymCellRight, 0, ev.makeCellFn("right"))
	te.bind(sexpr.NameSymCell, 0, te.makeCellFn(""))
	te.bind(sexpr.NameSymCellCenter, 0, te.makeCellFn("center"))
	te.bind(sexpr.NameSymCellLeft, 0, te.makeCellFn("left"))
	te.bind(sexpr.NameSymCellRight, 0, te.makeCellFn("right"))

	symDiv := ev.Make("div")
	ev.bind(sz.NameSymRegionBlock, 2, ev.makeRegionFn(symDiv, true))
	ev.bind(sz.NameSymRegionQuote, 2, ev.makeRegionFn(ev.Make("blockquote"), false))
	ev.bind(sz.NameSymRegionVerse, 2, ev.makeRegionFn(symDiv, false))
	te.bind(sexpr.NameSymRegionBlock, 2, te.makeRegionFn(te.Make("div"), true))
	te.bind(sexpr.NameSymRegionQuote, 2, te.makeRegionFn(te.Make("blockquote"), false))
	te.bind(sexpr.NameSymRegionVerse, 2, te.makeRegionFn(te.Make("div"), false))

	ev.bind(sz.NameSymVerbatimComment, 1, func(args []sx.Object, env *Environment) sx.Object {
		if ev.getAttributes(args[0], env).HasDefault() {
	te.bind(sexpr.NameSymVerbatimComment, 1, func(args *sxpf.List) sxpf.Object {
		if te.getAttributes(args).HasDefault() {
			if len(args) > 1 {
				if s := getString(args[1], env); s != "" {
					t := sx.String(s.String())
					return sx.Nil().Cons(t).Cons(ev.Make(sxhtml.NameSymBlockComment))
				}
			}
			if s := te.getString(args.Tail()); s != "" {
				t := sxpf.MakeString(s.String())
				return sxpf.Nil().Cons(t).Cons(te.Make(sxhtml.NameSymBlockComment))
			}
		}
		}
		return nil
	})

	ev.bind(sz.NameSymVerbatimEval, 2, func(args []sx.Object, env *Environment) sx.Object {
		return ev.evalVerbatim(ev.getAttributes(args[0], env).AddClass("zs-eval"), getString(args[1], env))
	te.bind(sexpr.NameSymVerbatimEval, 2, func(args *sxpf.List) sxpf.Object {
		return te.transformVerbatim(te.getAttributes(args).AddClass("zs-eval"), te.getString(args.Tail()))
	})
	ev.bind(sz.NameSymVerbatimHTML, 2, ev.evalHTML)
	ev.bind(sz.NameSymVerbatimMath, 2, func(args []sx.Object, env *Environment) sx.Object {
		return ev.evalVerbatim(ev.getAttributes(args[0], env).AddClass("zs-math"), getString(args[1], env))
	te.bind(sexpr.NameSymVerbatimHTML, 2, te.transformHTML)
	te.bind(sexpr.NameSymVerbatimMath, 2, func(args *sxpf.List) sxpf.Object {
		return te.transformVerbatim(te.getAttributes(args).AddClass("zs-math"), te.getString(args.Tail()))
	})
	ev.bind(sz.NameSymVerbatimProg, 2, func(args []sx.Object, env *Environment) sx.Object {
		a := ev.getAttributes(args[0], env)
		content := getString(args[1], env)
	te.bind(sexpr.NameSymVerbatimProg, 2, func(args *sxpf.List) sxpf.Object {
		a := te.getAttributes(args)
		content := te.getString(args.Tail())
		if a.HasDefault() {
			content = sx.String(visibleReplacer.Replace(content.String()))
			content = sxpf.MakeString(visibleReplacer.Replace(content.String()))
		}
		return ev.evalVerbatim(a, content)
		return te.transformVerbatim(a, content)
	})
	ev.bind(sz.NameSymVerbatimZettel, 0, nilFn)
	ev.bind(sz.NameSymBLOB, 3, func(args []sx.Object, env *Environment) sx.Object {
		return ev.evalBLOB(getList(args[0], env), getString(args[1], env), getString(args[2], env))
	te.bind(sexpr.NameSymVerbatimZettel, 0, func(*sxpf.List) sxpf.Object { return sxpf.Nil() })

	te.bind(sexpr.NameSymBLOB, 3, func(args *sxpf.List) sxpf.Object {
		argSyntax := args.Tail()
		return te.transformBLOB(te.getList(args), te.getString(argSyntax), te.getString(argSyntax.Tail()))
	})

	ev.bind(sz.NameSymTransclude, 2, func(args []sx.Object, env *Environment) sx.Object {
		ref, isPair := sx.GetPair(ev.eval(args[1], env))
		if !isPair {
			return sx.Nil()
	te.bind(sexpr.NameSymTransclude, 2, func(args *sxpf.List) sxpf.Object {
		ref, ok := args.Tail().Car().(*sxpf.List)
		if !ok {
			return sxpf.Nil()
		}
		refKind := ref.Car()
		if sx.IsNil(refKind) {
			return sx.Nil()
		if sxpf.IsNil(refKind) {
			return sxpf.Nil()
		}
		if refValue := getString(ref.Tail().Car(), env); refValue != "" {
			if refSym, isRefSym := sx.GetSymbol(refKind); isRefSym && refSym.Name() == sz.NameSymRefStateExternal {
				a := ev.getAttributes(args[0], env).Set("src", refValue.String()).AddClass("external")
				return sx.Nil().Cons(sx.Nil().Cons(ev.EvaluateAttrbute(a)).Cons(ev.Make("img"))).Cons(ev.symP)
		if refValue := te.getString(ref.Tail()); refValue != "" {
			if te.astSF.MustMake(sexpr.NameSymRefStateExternal).IsEqual(refKind) {
				a := te.getAttributes(args).Set("src", refValue.String()).AddClass("external")
				return sxpf.Nil().Cons(sxpf.Nil().Cons(te.transformAttribute(a)).Cons(te.Make("img"))).Cons(te.symP)
			}
			return sx.MakeList(
				ev.Make(sxhtml.NameSymInlineComment),
				sx.String("transclude"),
			return sxpf.MakeList(
				te.Make(sxhtml.NameSymInlineComment),
				sxpf.MakeString("transclude"),
				refKind,
				sx.String("->"),
				sxpf.MakeString("->"),
				refValue,
			)
		}
		return ev.evalSlice(args, env)
		return args
	})
}

func (ev *Evaluator) makeListFn(tag string) EvalFn {
	sym := ev.Make(tag)
	return func(args []sx.Object, env *Environment) sx.Object {
		result := sx.Nil().Cons(sym)
func (te *TransformEnv) makeListFn(tag string) transformFn {
	sym := te.Make(tag)
	return func(args *sxpf.List) sxpf.Object {
		result := sxpf.Nil().Cons(sym)
		last := result
		for _, elem := range args {
			item := sx.Nil().Cons(ev.symLI)
			if res, isPair := sx.GetPair(ev.eval(elem, env)); isPair {
		for elem := args; elem != nil; elem = elem.Tail() {
			item := sxpf.Nil().Cons(te.Make("li"))
			if res, ok := elem.Car().(*sxpf.List); ok {
				item.ExtendBang(res)
			}
			last = last.AppendBang(item)
		}
		return result
	}
}

func (te *TransformEnv) transformTableRow(cells *sxpf.List) *sxpf.List {
func (ev *Evaluator) evalTableRow(pairs *sx.Pair) *sx.Pair {
	row := sx.Nil().Cons(ev.Make("tr"))
	if pairs == nil {
		return nil
	row := sxpf.Nil().Cons(te.Make("tr"))
	if cells == nil {
		return sxpf.Nil()
	}
	curRow := row
	for pair := pairs; pair != nil; pair = pair.Tail() {
		curRow = curRow.AppendBang(pair.Car())
	for cell := cells; cell != nil; cell = cell.Tail() {
		curRow = curRow.AppendBang(cell.Car())
	}
	return row
}

func (ev *Evaluator) makeCellFn(align string) EvalFn {
	return func(args []sx.Object, env *Environment) sx.Object {
		tdata := ev.evalSlice(args, env)
func (te *TransformEnv) makeCellFn(align string) transformFn {
	return func(args *sxpf.List) sxpf.Object {
		tdata := args
		if align != "" {
			tdata = tdata.Cons(ev.EvaluateAttrbute(attrs.Attributes{"class": align}))
			tdata = tdata.Cons(te.transformAttribute(attrs.Attributes{"class": align}))
		}
		return tdata.Cons(ev.Make("td"))
		return tdata.Cons(te.Make("td"))
	}
}

func (ev *Evaluator) makeRegionFn(sym *sx.Symbol, genericToClass bool) EvalFn {
	return func(args []sx.Object, env *Environment) sx.Object {
		a := ev.getAttributes(args[0], env)
func (te *TransformEnv) makeRegionFn(sym *sxpf.Symbol, genericToClass bool) transformFn {
	return func(args *sxpf.List) sxpf.Object {
		a := te.getAttributes(args)
		env.pushAttributes(a)
		defer env.popAttributes()
		if genericToClass {
			if val, found := a.Get(""); found {
				a = a.Remove("").AddClass(val)
			}
		}
		result := sx.Nil()
		result := sxpf.Nil()
		if len(a) > 0 {
			result = result.Cons(ev.EvaluateAttrbute(a))
			result = result.Cons(te.transformAttribute(a))
		}
		result = result.Cons(sym)
		currResult := result.LastPair()
		if region, isPair := sx.GetPair(ev.eval(args[1], env)); isPair {
		currResult := result.Last()
		blockArg := args.Tail()
		if region, ok := blockArg.Car().(*sxpf.List); ok {
			currResult = currResult.ExtendBang(region)
		}
		if len(args) > 2 {
			if cite, isPair := sx.GetPair(ev.eval(args[2], env)); isPair && cite != nil {
				currResult.AppendBang(cite.Cons(ev.Make("cite")))
		if citeArg := blockArg.Tail(); citeArg != nil {
			if cite, ok := citeArg.Car().(*sxpf.List); ok && cite != nil {
				currResult.AppendBang(cite.Cons(te.Make("cite")))
			}
		}
		return result
	}
}

func (ev *Evaluator) evalVerbatim(a attrs.Attributes, s sx.String) sx.Object {
func (te *TransformEnv) transformVerbatim(a attrs.Attributes, s sxpf.String) sxpf.Object {
	a = setProgLang(a)
	code := sx.Nil().Cons(s)
	if al := ev.EvaluateAttrbute(a); al != nil {
	code := sxpf.Nil().Cons(s)
	if al := te.transformAttribute(a); al != nil {
		code = code.Cons(al)
	}
	code = code.Cons(ev.Make("code"))
	return sx.Nil().Cons(code).Cons(ev.Make("pre"))
	code = code.Cons(te.Make("code"))
	return sxpf.Nil().Cons(code).Cons(te.Make("pre"))
}

func (ev *Evaluator) bindInlines() {
	ev.bind(sz.NameSymInline, 0, ev.evalList)
	ev.bind(sz.NameSymText, 1, func(args []sx.Object, env *Environment) sx.Object { return getString(args[0], env) })
	ev.bind(sz.NameSymSpace, 0, func(args []sx.Object, env *Environment) sx.Object {
		if len(args) == 0 {
			return sx.String(" ")
func (te *TransformEnv) bindInlines() {
	te.bind(sexpr.NameSymInline, 0, listArgs)
	te.bind(sexpr.NameSymText, 1, func(args *sxpf.List) sxpf.Object { return te.getString(args) })
	te.bind(sexpr.NameSymSpace, 0, func(args *sxpf.List) sxpf.Object {
		if args.IsNil() {
			return sxpf.MakeString(" ")
		}
		return getString(args[0], env)
		return te.getString(args)
	})
	ev.bind(sz.NameSymSoft, 0, func([]sx.Object, *Environment) sx.Object { return sx.String(" ") })
	symBR := ev.Make("br")
	ev.bind(sz.NameSymHard, 0, func([]sx.Object, *Environment) sx.Object { return sx.Nil().Cons(symBR) })
	te.bind(sexpr.NameSymSoft, 0, func(*sxpf.List) sxpf.Object { return sxpf.MakeString(" ") })
	brSym := te.Make("br")
	te.bind(sexpr.NameSymHard, 0, func(*sxpf.List) sxpf.Object { return sxpf.Nil().Cons(brSym) })

	ev.bind(sz.NameSymLinkInvalid, 2, func(args []sx.Object, env *Environment) sx.Object {
		a := ev.getAttributes(args[0], env)
	te.bind(sexpr.NameSymLinkInvalid, 2, func(args *sxpf.List) sxpf.Object {
		// a := te.getAttributes(args)
		env.pushAttributes(a)
		defer env.popAttributes()
		var inline *sx.Pair
		if len(args) > 2 {
			inline = ev.evalSlice(args[2:], env)
		refArg := args.Tail()
		inline := refArg.Tail()
		}
		if inline == nil {
			inline = sx.Nil().Cons(ev.eval(args[1], env))
			inline = sxpf.Nil().Cons(refArg.Car())
		}
		return inline.Cons(ev.symSpan)
		return inline.Cons(te.symSpan)
	})
	evalHREF := func(args []sx.Object, env *Environment) sx.Object {
		a := ev.getAttributes(args[0], env)
	transformHREF := func(args *sxpf.List) sxpf.Object {
		a := te.getAttributes(args)
		env.pushAttributes(a)
		defer env.popAttributes()
		refValue := getString(args[1], env)
		return ev.evalLink(a.Set("href", refValue.String()), refValue, args[2:], env)
		refValue := te.getString(args.Tail())
		return te.transformLink(a.Set("href", refValue.String()), refValue, args.Tail().Tail())
	}
	ev.bind(sz.NameSymLinkZettel, 2, evalHREF)
	ev.bind(sz.NameSymLinkSelf, 2, evalHREF)
	ev.bind(sz.NameSymLinkFound, 2, evalHREF)
	ev.bind(sz.NameSymLinkBroken, 2, func(args []sx.Object, env *Environment) sx.Object {
		a := ev.getAttributes(args[0], env)
	te.bind(sexpr.NameSymLinkZettel, 2, transformHREF)
	te.bind(sexpr.NameSymLinkSelf, 2, transformHREF)
	te.bind(sexpr.NameSymLinkFound, 2, transformHREF)
	te.bind(sexpr.NameSymLinkBroken, 2, func(args *sxpf.List) sxpf.Object {
		a := te.getAttributes(args)
		env.pushAttributes(a)
		defer env.popAttributes()
		refValue := getString(args[1], env)
		return ev.evalLink(a.AddClass("broken"), refValue, args[2:], env)
		refValue := te.getString(args.Tail())
		return te.transformLink(a.AddClass("broken"), refValue, args.Tail().Tail())
	})
	ev.bind(sz.NameSymLinkHosted, 2, evalHREF)
	ev.bind(sz.NameSymLinkBased, 2, evalHREF)
	ev.bind(sz.NameSymLinkQuery, 2, func(args []sx.Object, env *Environment) sx.Object {
		a := ev.getAttributes(args[0], env)
	te.bind(sexpr.NameSymLinkHosted, 2, transformHREF)
	te.bind(sexpr.NameSymLinkBased, 2, transformHREF)
	te.bind(sexpr.NameSymLinkQuery, 2, func(args *sxpf.List) sxpf.Object {
		a := te.getAttributes(args)
		env.pushAttributes(a)
		defer env.popAttributes()
		refValue := getString(args[1], env)
		refValue := te.getString(args.Tail())
		query := "?" + api.QueryKeyQuery + "=" + url.QueryEscape(refValue.String())
		return ev.evalLink(a.Set("href", query), refValue, args[2:], env)
		return te.transformLink(a.Set("href", query), refValue, args.Tail().Tail())
	})
	ev.bind(sz.NameSymLinkExternal, 2, func(args []sx.Object, env *Environment) sx.Object {
		a := ev.getAttributes(args[0], env)
	te.bind(sexpr.NameSymLinkExternal, 2, func(args *sxpf.List) sxpf.Object {
		a := te.getAttributes(args)
		env.pushAttributes(a)
		defer env.popAttributes()
		refValue := getString(args[1], env)
		return ev.evalLink(a.Set("href", refValue.String()).AddClass("external"), refValue, args[2:], env)
		refValue := te.getString(args.Tail())
		return te.transformLink(a.Set("href", refValue.String()).AddClass("external"), refValue, args.Tail().Tail())
	})

	ev.bind(sz.NameSymEmbed, 3, func(args []sx.Object, env *Environment) sx.Object {
		ref := getList(ev.eval(args[1], env), env)
		syntax := getString(args[2], env)
	te.bind(sexpr.NameSymEmbed, 3, func(args *sxpf.List) sxpf.Object {
		argRef := args.Tail()
		ref := te.getList(argRef)
		syntax := te.getString(argRef.Tail())
		if syntax == api.ValueSyntaxSVG {
			embedAttr := sx.MakeList(
				ev.symAttr,
				sx.Cons(ev.Make("type"), sx.String("image/svg+xml")),
				sx.Cons(ev.Make("src"), sx.String("/"+getString(ref.Tail(), env).String()+".svg")),
			embedAttr := sxpf.MakeList(
				te.symAttr,
				sxpf.Cons(te.Make("type"), sxpf.MakeString("image/svg+xml")),
				sxpf.Cons(te.Make("src"), sxpf.MakeString("/"+te.getString(ref.Tail()).String()+".svg")),
			)
			return sx.MakeList(
				ev.Make("figure"),
				sx.MakeList(
					ev.Make("embed"),
			return sxpf.MakeList(
				te.Make("figure"),
				sxpf.MakeList(
					te.Make("embed"),
					embedAttr,
				),
			)
		}
		a := ev.getAttributes(args[0], env)
		a = a.Set("src", getString(ref.Tail().Car(), env).String())
		a := te.getAttributes(args)
		a = a.Set("src", string(te.getString(ref.Tail())))
		if len(args) > 3 {
			var sb strings.Builder
			flattenText(&sb, sx.MakeList(args[3:]...))
			if d := sb.String(); d != "" {
				a = a.Set("alt", d)
			}
		var sb strings.Builder
		te.flattenText(&sb, ref.Tail().Tail().Tail())
		if d := sb.String(); d != "" {
			a = a.Set("alt", d)
		}
		}
		return sx.MakeList(ev.Make("img"), ev.EvaluateAttrbute(a))
		return sxpf.MakeList(te.Make("img"), te.transformAttribute(a))
	})
	ev.bind(sz.NameSymEmbedBLOB, 3, func(args []sx.Object, env *Environment) sx.Object {
		a, syntax, data := ev.getAttributes(args[0], env), getString(args[1], env), getString(args[2], env)
		summary, hasSummary := a.Get(api.KeySummary)
	te.bind(sexpr.NameSymEmbedBLOB, 3, func(args *sxpf.List) sxpf.Object {
		argSyntax := args.Tail()
		a, syntax, data := te.getAttributes(args), te.getString(argSyntax), te.getString(argSyntax.Tail())
		summary, _ := a.Get(api.KeySummary)
		if !hasSummary {
			summary = ""
		}
		return ev.evalBLOB(
			sx.MakeList(ev.Make(sx.ListName), sx.String(summary)),
		return te.transformBLOB(
			sxpf.MakeList(te.astSF.MustMake(sexpr.NameSymInline), sxpf.MakeString(summary)),
			syntax,
			data,
		)
	})

	ev.bind(sz.NameSymCite, 2, func(args []sx.Object, env *Environment) sx.Object {
	te.bind(sexpr.NameSymCite, 2, func(args *sxpf.List) sxpf.Object {
		a := ev.getAttributes(args[0], env)
		env.pushAttributes(a)
		defer env.popAttributes()
		result := sx.Nil()
		if key := getString(args[1], env); key != "" {
			if len(args) > 2 {
				result = ev.evalSlice(args[2:], env).Cons(sx.String(", "))
		result := sxpf.Nil()
		argKey := args.Tail()
		if key := te.getString(argKey); key != "" {
			if text := argKey.Tail(); text != nil {
				result = text.Cons(sxpf.MakeString(", "))
			}
			result = result.Cons(key)
		}
		if len(a) > 0 {
			result = result.Cons(ev.EvaluateAttrbute(a))
		if a := te.getAttributes(args); len(a) > 0 {
			result = result.Cons(te.transformAttribute(a))
		}
		if result == nil {
			return nil
		}
		return result.Cons(ev.symSpan)
		return result.Cons(te.symSpan)
	})
	ev.bind(sz.NameSymMark, 3, func(args []sx.Object, env *Environment) sx.Object {
		result := ev.evalSlice(args[3:], env)
		if !ev.noLinks {
			if fragment := getString(args[2], env); fragment != "" {
				a := attrs.Attributes{"id": fragment.String() + ev.unique}
				return result.Cons(ev.EvaluateAttrbute(a)).Cons(ev.symA)
			}
		}
		return result.Cons(ev.symSpan)

	te.bind(sexpr.NameSymMark, 3, func(args *sxpf.List) sxpf.Object {
		argFragment := args.Tail().Tail()
		result := argFragment.Tail()
		if !te.tr.noLinks {
			if fragment := te.getString(argFragment); fragment != "" {
				a := attrs.Attributes{"id": fragment.String() + te.tr.unique}
				return result.Cons(te.transformAttribute(a)).Cons(te.symA)
			}
		}
		return result.Cons(te.symSpan)
	})

	ev.bind(sz.NameSymEndnote, 1, func(args []sx.Object, env *Environment) sx.Object {
	te.bind(sexpr.NameSymEndnote, 1, func(args *sxpf.List) sxpf.Object {
		a := ev.getAttributes(args[0], env)
		env.pushAttributes(a)
		defer env.popAttributes()
		attrPlist := sx.Nil()
		if len(a) > 0 {
			if attrs := ev.EvaluateAttrbute(a); attrs != nil {
		attrPlist := sxpf.Nil()
		if a := te.getAttributes(args); len(a) > 0 {
			if attrs := te.transformAttribute(a); attrs != nil {
				attrPlist = attrs.Tail()
			}
		}

		text, isPair := sx.GetPair(args[1])
		if !isPair {
			return sx.Nil()
		}
		noteNum := strconv.Itoa(len(env.endnotes) + 1)
		noteID := ev.unique + noteNum
		env.endnotes = append(env.endnotes, endnoteInfo{
			noteID: noteID, noteAST: ev.eval(text, env), noteHx: nil, attrs: attrPlist})
		hrefAttr := sx.Nil().Cons(sx.Cons(ev.Make("role"), sx.String("doc-noteref"))).
			Cons(sx.Cons(ev.symHREF, sx.String("#fn:"+noteID))).
			Cons(sx.Cons(ev.symClass, sx.String("zs-noteref"))).
			Cons(ev.symAttr)
		href := sx.Nil().Cons(sx.String(noteNum)).Cons(hrefAttr).Cons(ev.symA)
		supAttr := sx.Nil().Cons(sx.Cons(ev.Make("id"), sx.String("fnref:"+noteID))).Cons(ev.symAttr)
		return sx.Nil().Cons(href).Cons(supAttr).Cons(ev.Make("sup"))

		text, ok := args.Tail().Car().(*sxpf.List)
		if !ok {
			return sxpf.Nil()
		}
		te.tr.endnotes = append(te.tr.endnotes, endnoteInfo{noteAST: text, noteHx: nil, attrs: attrPlist})
		noteNum := strconv.Itoa(len(te.tr.endnotes))
		noteID := te.tr.unique + noteNum
		hrefAttr := sxpf.Nil().Cons(sxpf.Cons(te.Make("role"), sxpf.MakeString("doc-noteref"))).
			Cons(sxpf.Cons(te.Make("href"), sxpf.MakeString("#fn:"+noteID))).
			Cons(sxpf.Cons(te.tr.symClass, sxpf.MakeString("zs-noteref"))).
			Cons(te.symAttr)
		href := sxpf.Nil().Cons(sxpf.MakeString(noteNum)).Cons(hrefAttr).Cons(te.symA)
		supAttr := sxpf.Nil().Cons(sxpf.Cons(te.Make("id"), sxpf.MakeString("fnref:"+noteID))).Cons(te.symAttr)
		return sxpf.Nil().Cons(href).Cons(supAttr).Cons(te.Make("sup"))
	})

	ev.bind(sz.NameSymFormatDelete, 1, ev.makeFormatFn("del"))
	ev.bind(sz.NameSymFormatEmph, 1, ev.makeFormatFn("em"))
	ev.bind(sz.NameSymFormatInsert, 1, ev.makeFormatFn("ins"))
	te.bind(sexpr.NameSymFormatDelete, 1, te.makeFormatFn("del"))
	te.bind(sexpr.NameSymFormatEmph, 1, te.makeFormatFn("em"))
	te.bind(sexpr.NameSymFormatInsert, 1, te.makeFormatFn("ins"))
	ev.bind(sz.NameSymFormatMark, 1, ev.makeFormatFn("mark"))
	ev.bind(sz.NameSymFormatQuote, 1, ev.evalQuote)
	ev.bind(sz.NameSymFormatSpan, 1, ev.makeFormatFn("span"))
	ev.bind(sz.NameSymFormatStrong, 1, ev.makeFormatFn("strong"))
	ev.bind(sz.NameSymFormatSub, 1, ev.makeFormatFn("sub"))
	ev.bind(sz.NameSymFormatSuper, 1, ev.makeFormatFn("sup"))
	te.bind(sexpr.NameSymFormatQuote, 1, te.transformQuote)
	te.bind(sexpr.NameSymFormatSpan, 1, te.makeFormatFn("span"))
	te.bind(sexpr.NameSymFormatStrong, 1, te.makeFormatFn("strong"))
	te.bind(sexpr.NameSymFormatSub, 1, te.makeFormatFn("sub"))
	te.bind(sexpr.NameSymFormatSuper, 1, te.makeFormatFn("sup"))

	ev.bind(sz.NameSymLiteralComment, 1, func(args []sx.Object, env *Environment) sx.Object {
		if ev.getAttributes(args[0], env).HasDefault() {
	te.bind(sexpr.NameSymLiteralComment, 1, func(args *sxpf.List) sxpf.Object {
		if te.getAttributes(args).HasDefault() {
			if len(args) > 1 {
				if s := getString(ev.eval(args[1], env), env); s != "" {
					return sx.Nil().Cons(s).Cons(ev.Make(sxhtml.NameSymInlineComment))
				}
			}
			if s := te.getString(args.Tail()); s != "" {
				return sxpf.Nil().Cons(s).Cons(te.Make(sxhtml.NameSymInlineComment))
			}
		}
		}
		return sx.Nil()
		return sxpf.Nil()
	})
	ev.bind(sz.NameSymLiteralHTML, 2, ev.evalHTML)
	kbdSym := ev.Make("kbd")
	te.bind(sexpr.NameSymLiteralHTML, 2, te.transformHTML)
	kbdSym := te.Make("kbd")
	ev.bind(sz.NameSymLiteralInput, 2, func(args []sx.Object, env *Environment) sx.Object {
		return ev.evalLiteral(args, nil, kbdSym, env)
	})
	codeSym := ev.Make("code")
	ev.bind(sz.NameSymLiteralMath, 2, func(args []sx.Object, env *Environment) sx.Object {
		a := ev.getAttributes(args[0], env).AddClass("zs-math")
		return ev.evalLiteral(args, a, codeSym, env)
	})
	sampSym := ev.Make("samp")
	ev.bind(sz.NameSymLiteralOutput, 2, func(args []sx.Object, env *Environment) sx.Object {
		return ev.evalLiteral(args, nil, sampSym, env)
	})
	ev.bind(sz.NameSymLiteralProg, 2, func(args []sx.Object, env *Environment) sx.Object {
		return ev.evalLiteral(args, nil, codeSym, env)
	})

	ev.bind(sz.NameSymLiteralZettel, 0, nilFn)
}

func (ev *Evaluator) makeFormatFn(tag string) EvalFn {
	sym := ev.Make(tag)
	return func(args []sx.Object, env *Environment) sx.Object {
		a := ev.getAttributes(args[0], env)
	te.bind(sexpr.NameSymLiteralInput, 2, func(args *sxpf.List) sxpf.Object {
		return te.transformLiteral(args, nil, kbdSym)
		env.pushAttributes(a)
		defer env.popAttributes()
		if val, hasClass := a.Get(""); hasClass {
			a = a.Remove("").AddClass(val)
		}
		res := ev.evalSlice(args[1:], env)
	})
	codeSym := te.Make("code")
		if len(a) > 0 {
			res = res.Cons(ev.EvaluateAttrbute(a))
		}
		return res.Cons(sym)
	}
}
	te.bind(sexpr.NameSymLiteralMath, 2, func(args *sxpf.List) sxpf.Object {
		a := te.getAttributes(args).AddClass("zs-math")
		return te.transformLiteral(args, a, codeSym)
	})
	sampSym := te.Make("samp")
	te.bind(sexpr.NameSymLiteralOutput, 2, func(args *sxpf.List) sxpf.Object {
		return te.transformLiteral(args, nil, sampSym)
	})
	te.bind(sexpr.NameSymLiteralProg, 2, func(args *sxpf.List) sxpf.Object {
		return te.transformLiteral(args, nil, codeSym)
	})

type quoteData struct {
	primLeft, primRight string
	te.bind(sexpr.NameSymLiteralZettel, 0, func(*sxpf.List) sxpf.Object { return sxpf.Nil() })
	secLeft, secRight   string
	nbsp                bool
}

var langQuotes = map[string]quoteData{
	"":              {"&quot;", "&quot;", "&quot;", "&quot;", false},
	api.ValueLangEN: {"&ldquo;", "&rdquo;", "&lsquo;", "&rsquo;", false},
	"de":            {"&bdquo;", "&ldquo;", "&sbquo;", "&lsquo;", false},
	"fr":            {"&laquo;", "&raquo;", "&lsaquo;", "&rsaquo;", true},
}


func (te *TransformEnv) makeFormatFn(tag string) transformFn {
func getQuoteData(lang string) quoteData {
	langFields := strings.FieldsFunc(lang, func(r rune) bool { return r == '-' || r == '_' })
	for len(langFields) > 0 {
		langSup := strings.Join(langFields, "-")
		quotes, ok := langQuotes[langSup]
	sym := te.Make(tag)
		if ok {
			return quotes
	return func(args *sxpf.List) sxpf.Object {
		a := te.getAttributes(args)
		if val, found := a.Get(""); found {
			a = a.Remove("").AddClass(val)
		}
		res := args.Tail()
		langFields = langFields[0 : len(langFields)-1]
		if len(a) > 0 {
	}
	return langQuotes[""]
}

			res = res.Cons(te.transformAttribute(a))
func getQuotes(data *quoteData, env *Environment) (string, string) {
	if env.quoteNesting%2 == 0 {
		return data.primLeft, data.primRight
	}
	return data.secLeft, data.secRight
}

func (ev *Evaluator) evalQuote(args []sx.Object, env *Environment) sx.Object {
	a := ev.getAttributes(args[0], env)
	env.pushAttributes(a)
	defer env.popAttributes()

	if val, hasClass := a.Get(""); hasClass {
		}
		return res.Cons(sym)
	}
}
func (te *TransformEnv) transformQuote(args *sxpf.List) sxpf.Object {
	const langAttr = "lang"
	a := te.getAttributes(args)
	langVal, found := a.Get(langAttr)
	if found {
		a = a.Remove(langAttr)
	}
	if val, found2 := a.Get(""); found2 {
		a = a.Remove("").AddClass(val)
	}
	quotes := getQuoteData(env.getLanguage())
	leftQ, rightQ := getQuotes(&quotes, env)

	res := args.Tail()
	env.quoteNesting++
	res := ev.evalSlice(args[1:], env)
	env.quoteNesting--

	lastPair := res.LastPair()
	if lastPair.IsNil() {
		res = sx.Cons(sx.MakeList(ev.symNoEscape, sx.String(leftQ), sx.String(rightQ)), sx.Nil())
	} else {
		if quotes.nbsp {
			lastPair.AppendBang(sx.MakeList(ev.symNoEscape, sx.String("&nbsp;"), sx.String(rightQ)))
			res = res.Cons(sx.MakeList(ev.symNoEscape, sx.String(leftQ), sx.String("&nbsp;")))
		} else {
			lastPair.AppendBang(sx.MakeList(ev.symNoEscape, sx.String(rightQ)))
			res = res.Cons(sx.MakeList(ev.symNoEscape, sx.String(leftQ)))
		}
	}
	if len(a) > 0 {
		res = res.Cons(te.transformAttribute(a))
	}
		res = res.Cons(ev.EvaluateAttrbute(a))
		return res.Cons(ev.symSpan)
	res = res.Cons(te.Make("q"))
	if found {
		res = sxpf.Nil().Cons(res).Cons(te.transformAttribute(attrs.Attributes{}.Set(langAttr, langVal))).Cons(te.symSpan)
	}
	return res.Cons(ev.symList)
	return res
}

var visibleReplacer = strings.NewReplacer(" ", "\u2423")

func (ev *Evaluator) evalLiteral(args []sx.Object, a attrs.Attributes, sym *sx.Symbol, env *Environment) sx.Object {
func (te *TransformEnv) transformLiteral(args *sxpf.List, a attrs.Attributes, sym *sxpf.Symbol) sxpf.Object {
	if a == nil {
		a = ev.getAttributes(args[0], env)
		a = te.getAttributes(args)
	}
	a = setProgLang(a)
	literal := getString(args[1], env).String()
	literal := te.getString(args.Tail()).String()
	if a.HasDefault() {
		a = a.RemoveDefault()
		literal = visibleReplacer.Replace(literal)
	}
	res := sx.Nil().Cons(sx.String(literal))
	res := sxpf.Nil().Cons(sxpf.MakeString(literal))
	if len(a) > 0 {
		res = res.Cons(ev.EvaluateAttrbute(a))
		res = res.Cons(te.transformAttribute(a))
	}
	return res.Cons(sym)
}

func setProgLang(a attrs.Attributes) attrs.Attributes {
	if val, found := a.Get(""); found {
		a = a.AddClass("language-" + val).Remove("")
	}
	return a
}

func (ev *Evaluator) evalHTML(args []sx.Object, env *Environment) sx.Object {
	if s := getString(ev.eval(args[1], env), env); s != "" && IsSafe(s.String()) {
		return sx.Nil().Cons(s).Cons(ev.symNoEscape)
func (te *TransformEnv) transformHTML(args *sxpf.List) sxpf.Object {
	if s := te.getString(args.Tail()); s != "" && IsSafe(s.String()) {
		return sxpf.Nil().Cons(s).Cons(te.symNoEscape)
	}
	return nil
}

func (ev *Evaluator) evalBLOB(description *sx.Pair, syntax, data sx.String) sx.Object {
func (te *TransformEnv) transformBLOB(description *sxpf.List, syntax, data sxpf.String) sxpf.Object {
	if data == "" {
		return sx.Nil()
		return sxpf.Nil()
	}
	switch syntax {
	case "":
		return sx.Nil()
		return sxpf.Nil()
	case api.ValueSyntaxSVG:
		return sx.Nil().Cons(sx.Nil().Cons(data).Cons(ev.symNoEscape)).Cons(ev.symP)
		return sxpf.Nil().Cons(sxpf.Nil().Cons(data).Cons(te.symNoEscape)).Cons(te.symP)
	default:
		imgAttr := sx.Nil().Cons(sx.Cons(ev.Make("src"), sx.String("data:image/"+syntax.String()+";base64,"+data.String())))
		imgAttr := sxpf.Nil().Cons(sxpf.Cons(te.Make("src"), sxpf.MakeString("data:image/"+syntax.String()+";base64,"+data.String())))
		var sb strings.Builder
		flattenText(&sb, description)
		te.flattenText(&sb, description)
		if d := sb.String(); d != "" {
			imgAttr = imgAttr.Cons(sx.Cons(ev.Make("alt"), sx.String(d)))
			imgAttr = imgAttr.Cons(sxpf.Cons(te.Make("alt"), sxpf.MakeString(d)))
		}
		return sx.Nil().Cons(sx.Nil().Cons(imgAttr.Cons(ev.symAttr)).Cons(ev.Make("img"))).Cons(ev.symP)
		return sxpf.Nil().Cons(sxpf.Nil().Cons(imgAttr.Cons(te.symAttr)).Cons(te.Make("img"))).Cons(te.symP)
	}
}

func flattenText(sb *strings.Builder, lst *sx.Pair) {
	for elem := lst; elem != nil; elem = elem.Tail() {
		switch obj := elem.Car().(type) {
		case sx.String:
			sb.WriteString(obj.String())
		case *sx.Symbol:
			if obj.Name() == sz.NameSymSpace {
				sb.WriteByte(' ')
				break
			}
		case *sx.Pair:
			flattenText(sb, obj)
		}
	}
}


func (te *TransformEnv) flattenText(sb *strings.Builder, lst *sxpf.List) {
	for elem := lst; elem != nil; elem = elem.Tail() {
		switch obj := elem.Car().(type) {
		case sxpf.String:
			sb.WriteString(obj.String())
		case *sxpf.List:
			te.flattenText(sb, obj)
		}
	}
}
func (ev *Evaluator) evalList(args []sx.Object, env *Environment) sx.Object {
	return ev.evalSlice(args, env)
}

func nilFn([]sx.Object, *Environment) sx.Object { return sx.Nil() }

type transformFn func(*sxpf.List) sxpf.Object
func (ev *Evaluator) eval(obj sx.Object, env *Environment) sx.Object {
	if env.err != nil {
		return sx.Nil()
	}

	if sx.IsNil(obj) {
		return obj
func (te *TransformEnv) bind(name string, minArity int, fn transformFn) {
	}
	lst, isLst := sx.GetPair(obj)
	te.astEnv.Bind(te.astSF.MustMake(name), eval.MakeBuiltin(name, func(_ sxpf.Environment, args *sxpf.List) (sxpf.Object, error) {
		if nArgs := args.Length(); nArgs < minArity {
	if !isLst {
		return obj
	}
	sym, found := sx.GetSymbol(lst.Car())
			return sxpf.Nil(), fmt.Errorf("not enough arguments (%d) for form %v (%d)", nArgs, name, minArity)
		}
		res := fn(args)
	if !found {
		env.err = fmt.Errorf("symbol expected, but got %T/%v", lst.Car(), lst.Car())
		return sx.Nil()
	}
	name := sym.Name()
	fn, found := ev.fns[name]
		return res, te.err
	}))
}

func (te *TransformEnv) Rebind(name string, fn func(sxpf.Environment, *sxpf.List, sxpf.Callable) sxpf.Object) {
	sym := te.astSF.MustMake(name)
	obj, found := te.astEnv.Lookup(sym)
	if !found {
		env.err = fmt.Errorf("symbol %q not bound", name)
		return sx.Nil()
		panic(sym.String())
	}
	var args []sx.Object
	for cdr := lst.Cdr(); !sx.IsNil(cdr); {
	preFn, ok := obj.(sxpf.Callable)
		pair, isPair := sx.GetPair(cdr)
		if !isPair {
	if !ok {
			break
		}
		args = append(args, pair.Car())
		cdr = pair.Cdr()
		panic(sym.String())
	}
	if minArgs, hasMinArgs := ev.minArgs[name]; hasMinArgs {
		if minArgs > len(args) {
	te.astEnv.Bind(sym, eval.MakeBuiltin(name, func(env sxpf.Environment, args *sxpf.List) (sxpf.Object, error) {
		res := fn(env, args, preFn)
			env.err = fmt.Errorf("%v needs at least %d arguments, but got only %d", name, minArgs, len(args))
			return sx.Nil()
		}
	}
	result := fn(args, env)
	if env.err != nil {
		return sx.Nil()
		return res, te.err
	}))
}

func (te *TransformEnv) Make(name string) *sxpf.Symbol { return te.tr.Make(name) }
func (te *TransformEnv) getString(lst *sxpf.List) sxpf.String {
	if te.err != nil {
		return ""
	}
	val := lst.Car()
	if s, ok := val.(sxpf.String); ok {
	return result
}

		return s
	}
	te.err = fmt.Errorf("%v/%T is not a string", val, val)
func (ev *Evaluator) evalSlice(args []sx.Object, env *Environment) *sx.Pair {
	result := sx.Cons(sx.Nil(), sx.Nil())
	curr := result
	for _, arg := range args {
		elem := ev.eval(arg, env)
		if env.err != nil {
			return nil
		}
		curr = curr.AppendBang(elem)
	return ""
}
func (te *TransformEnv) getInt64(lst *sxpf.List) int64 {
	if te.err != nil {
	}
	return result.Tail()
}

		return -1017
	}
	val := lst.Car()
func (ev *Evaluator) evalLink(a attrs.Attributes, refValue sx.String, inline []sx.Object, env *Environment) sx.Object {
	result := ev.evalSlice(inline, env)
	if num, ok := val.(*sxpf.Number); ok {
	if len(inline) == 0 {
		result = sx.Nil().Cons(refValue)
	}
	if ev.noLinks {
		return result.Cons(ev.symSpan)
		return num.GetInt64()
	}
	te.err = fmt.Errorf("%v/%T is not a number", val, val)
	return result.Cons(ev.EvaluateAttrbute(a)).Cons(ev.symA)
	return -1017
}

func (te *TransformEnv) getList(lst *sxpf.List) *sxpf.List {
func (ev *Evaluator) getSymbol(val sx.Object, env *Environment) *sx.Symbol {
	if env.err == nil {
		if sym, ok := sx.GetSymbol(val); ok {
			return sym
	if te.err == nil {
		val := lst.Car()
		if res, ok := val.(*sxpf.List); ok {
			return res
		}
		env.err = fmt.Errorf("%v/%T is not a symbol", val, val)
		te.err = fmt.Errorf("%v/%T is not a list", val, val)
	}
	return ev.Make("???")
	return sxpf.Nil()
}
func getString(val sx.Object, env *Environment) sx.String {
	if env.err != nil {
		return ""
	}
func (te *TransformEnv) getAttributes(args *sxpf.List) attrs.Attributes {
	return sexpr.GetAttributes(te.getList(args))
}
	if s, ok := sx.GetString(val); ok {
		return s
	}

	env.err = fmt.Errorf("%v/%T is not a string", val, val)
	return ""
}
func (te *TransformEnv) transformLink(a attrs.Attributes, refValue sxpf.String, inline *sxpf.List) sxpf.Object {
	result := inline
	if inline.IsNil() {
		result = sxpf.Nil().Cons(refValue)
	}
func getList(val sx.Object, env *Environment) *sx.Pair {
	if env.err == nil {
	if te.tr.noLinks {
		if res, isPair := sx.GetPair(val); isPair {
			return res
		}
		return result.Cons(te.symSpan)
	}
		env.err = fmt.Errorf("%v/%T is not a list", val, val)
	}
	return result.Cons(te.transformAttribute(a)).Cons(te.symA)
}
	return nil
}

func getInt64(val sx.Object, env *Environment) int64 {
	if env.err != nil {
		return -1017
	}
func (te *TransformEnv) transformAttribute(a attrs.Attributes) *sxpf.List {
	return te.tr.TransformAttrbute(a)
}
	if num, ok := sx.GetNumber(val); ok {
		return int64(num.(sx.Int64))
	}

	env.err = fmt.Errorf("%v/%T is not a number", val, val)
	return -1017
func (te *TransformEnv) transformMeta(a attrs.Attributes) *sxpf.List {
	return te.tr.TransformMeta(a)
}
func (ev *Evaluator) getAttributes(arg sx.Object, env *Environment) attrs.Attributes {
	return sz.GetAttributes(getList(ev.eval(arg, env), env))
}

var unsafeSnippets = []string{
	"<script", "</script",
	"<iframe", "</iframe",
}

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

package sz

import "zettelstore.de/sx.fossil"

// Various constants for Zettel data. Some of them are technically variables.

const (
	// Symbols for Metanodes
	NameSymBlock  = "BLOCK"
	NameSymInline = "INLINE"
	NameSymMeta   = "META"

	// Symbols for Zettel node types.
	NameSymBLOB            = "BLOB"
	NameSymCell            = "CELL"
	NameSymCellCenter      = "CELL-CENTER"
	NameSymCellLeft        = "CELL-LEFT"
	NameSymCellRight       = "CELL-RIGHT"
	NameSymCite            = "CITE"
	NameSymDescription     = "DESCRIPTION"
	NameSymEmbed           = "EMBED"
	NameSymEmbedBLOB       = "EMBED-BLOB"
	NameSymEndnote         = "ENDNOTE"
	NameSymFormatEmph      = "FORMAT-EMPH"
	NameSymFormatDelete    = "FORMAT-DELETE"
	NameSymFormatInsert    = "FORMAT-INSERT"
	NameSymFormatMark      = "FORMAT-MARK"
	NameSymFormatQuote     = "FORMAT-QUOTE"
	NameSymFormatSpan      = "FORMAT-SPAN"
	NameSymFormatSub       = "FORMAT-SUB"
	NameSymFormatSuper     = "FORMAT-SUPER"
	NameSymFormatStrong    = "FORMAT-STRONG"
	NameSymHard            = "HARD"
	NameSymHeading         = "HEADING"
	NameSymLinkInvalid     = "LINK-INVALID"
	NameSymLinkZettel      = "LINK-ZETTEL"
	NameSymLinkSelf        = "LINK-SELF"
	NameSymLinkFound       = "LINK-FOUND"
	NameSymLinkBroken      = "LINK-BROKEN"
	NameSymLinkHosted      = "LINK-HOSTED"
	NameSymLinkBased       = "LINK-BASED"
	NameSymLinkQuery       = "LINK-QUERY"
	NameSymLinkExternal    = "LINK-EXTERNAL"
	NameSymListOrdered     = "ORDERED"
	NameSymListUnordered   = "UNORDERED"
	NameSymListQuote       = "QUOTATION"
	NameSymLiteralProg     = "LITERAL-CODE"
	NameSymLiteralComment  = "LITERAL-COMMENT"
	NameSymLiteralHTML     = "LITERAL-HTML"
	NameSymLiteralInput    = "LITERAL-INPUT"
	NameSymLiteralMath     = "LITERAL-MATH"
	NameSymLiteralOutput   = "LITERAL-OUTPUT"
	NameSymLiteralZettel   = "LITERAL-ZETTEL"
	NameSymMark            = "MARK"
	NameSymPara            = "PARA"
	NameSymRegionBlock     = "REGION-BLOCK"
	NameSymRegionQuote     = "REGION-QUOTE"
	NameSymRegionVerse     = "REGION-VERSE"
	NameSymSoft            = "SOFT"
	NameSymSpace           = "SPACE"
	NameSymTable           = "TABLE"
	NameSymText            = "TEXT"
	NameSymThematic        = "THEMATIC"
	NameSymTransclude      = "TRANSCLUDE"
	NameSymUnknown         = "UNKNOWN-NODE"
	NameSymVerbatimComment = "VERBATIM-COMMENT"
	NameSymVerbatimEval    = "VERBATIM-EVAL"
	NameSymVerbatimHTML    = "VERBATIM-HTML"
	NameSymVerbatimMath    = "VERBATIM-MATH"
	NameSymVerbatimProg    = "VERBATIM-CODE"
	NameSymVerbatimZettel  = "VERBATIM-ZETTEL"

	// Constant symbols for reference states.
	NameSymRefStateInvalid  = "INVALID"
	NameSymRefStateZettel   = "ZETTEL"
	NameSymRefStateSelf     = "SELF"
	NameSymRefStateFound    = "FOUND"
	NameSymRefStateBroken   = "BROKEN"
	NameSymRefStateHosted   = "HOSTED"
	NameSymRefStateBased    = "BASED"
	NameSymRefStateQuery    = "QUERY"
	NameSymRefStateExternal = "EXTERNAL"

	// Symbols for metadata types.
	NameSymTypeCredential   = "CREDENTIAL"
	NameSymTypeEmpty        = "EMPTY-STRING"
	NameSymTypeID           = "ZID"
	NameSymTypeIDSet        = "ZID-SET"
	NameSymTypeNumber       = "NUMBER"
	NameSymTypeString       = "STRING"
	NameSymTypeTagSet       = "TAG-SET"
	NameSymTypeTimestamp    = "TIMESTAMP"
	NameSymTypeURL          = "URL"
	NameSymTypeWord         = "WORD"
	NameSymTypeWordSet      = "WORD-SET"
	NameSymTypeZettelmarkup = "ZETTELMARKUP"
)

// ZettelSymbols collect all symbols needed to represent zettel data.
type ZettelSymbols struct {
	// Symbols for Metanodes
	SymBlock  *sx.Symbol
	SymInline *sx.Symbol
	SymList   *sx.Symbol
	SymMeta   *sx.Symbol
	SymQuote  *sx.Symbol

	// Symbols for Zettel node types.
	SymBLOB            *sx.Symbol
	SymCell            *sx.Symbol
	SymCellCenter      *sx.Symbol
	SymCellLeft        *sx.Symbol
	SymCellRight       *sx.Symbol
	SymCite            *sx.Symbol
	SymDescription     *sx.Symbol
	SymEmbed           *sx.Symbol
	SymEmbedBLOB       *sx.Symbol
	SymEndnote         *sx.Symbol
	SymFormatEmph      *sx.Symbol
	SymFormatDelete    *sx.Symbol
	SymFormatInsert    *sx.Symbol
	SymFormatMark      *sx.Symbol
	SymFormatQuote     *sx.Symbol
	SymFormatSpan      *sx.Symbol
	SymFormatSub       *sx.Symbol
	SymFormatSuper     *sx.Symbol
	SymFormatStrong    *sx.Symbol
	SymHard            *sx.Symbol
	SymHeading         *sx.Symbol
	SymLinkInvalid     *sx.Symbol
	SymLinkZettel      *sx.Symbol
	SymLinkSelf        *sx.Symbol
	SymLinkFound       *sx.Symbol
	SymLinkBroken      *sx.Symbol
	SymLinkHosted      *sx.Symbol
	SymLinkBased       *sx.Symbol
	SymLinkQuery       *sx.Symbol
	SymLinkExternal    *sx.Symbol
	SymListOrdered     *sx.Symbol
	SymListUnordered   *sx.Symbol
	SymListQuote       *sx.Symbol
	SymLiteralProg     *sx.Symbol
	SymLiteralComment  *sx.Symbol
	SymLiteralHTML     *sx.Symbol
	SymLiteralInput    *sx.Symbol
	SymLiteralMath     *sx.Symbol
	SymLiteralOutput   *sx.Symbol
	SymLiteralZettel   *sx.Symbol
	SymMark            *sx.Symbol
	SymPara            *sx.Symbol
	SymRegionBlock     *sx.Symbol
	SymRegionQuote     *sx.Symbol
	SymRegionVerse     *sx.Symbol
	SymSoft            *sx.Symbol
	SymSpace           *sx.Symbol
	SymTable           *sx.Symbol
	SymText            *sx.Symbol
	SymThematic        *sx.Symbol
	SymTransclude      *sx.Symbol
	SymUnknown         *sx.Symbol
	SymVerbatimComment *sx.Symbol
	SymVerbatimEval    *sx.Symbol
	SymVerbatimHTML    *sx.Symbol
	SymVerbatimMath    *sx.Symbol
	SymVerbatimProg    *sx.Symbol
	SymVerbatimZettel  *sx.Symbol

	// Constant symbols for reference states.

	SymRefStateInvalid  *sx.Symbol
	SymRefStateZettel   *sx.Symbol
	SymRefStateSelf     *sx.Symbol
	SymRefStateFound    *sx.Symbol
	SymRefStateBroken   *sx.Symbol
	SymRefStateHosted   *sx.Symbol
	SymRefStateBased    *sx.Symbol
	SymRefStateQuery    *sx.Symbol
	SymRefStateExternal *sx.Symbol

	// Symbols for metadata types

	SymTypeCredential   *sx.Symbol
	SymTypeEmpty        *sx.Symbol
	SymTypeID           *sx.Symbol
	SymTypeIDSet        *sx.Symbol
	SymTypeNumber       *sx.Symbol
	SymTypeString       *sx.Symbol
	SymTypeTagSet       *sx.Symbol
	SymTypeTimestamp    *sx.Symbol
	SymTypeURL          *sx.Symbol
	SymTypeWord         *sx.Symbol
	SymTypeWordSet      *sx.Symbol
	SymTypeZettelmarkup *sx.Symbol
}

func (zs *ZettelSymbols) InitializeZettelSymbols(sf sx.SymbolFactory) {
	// Symbols for Metanodes
	zs.SymBlock = sf.MustMake(NameSymBlock)
	zs.SymInline = sf.MustMake(NameSymInline)
	zs.SymList = sf.MustMake(sx.ListName)
	zs.SymMeta = sf.MustMake(NameSymMeta)
	zs.SymQuote = sf.MustMake(sx.QuoteName)

	// Symbols for Zettel node types.
	zs.SymBLOB = sf.MustMake(NameSymBLOB)
	zs.SymCell = sf.MustMake(NameSymCell)
	zs.SymCellCenter = sf.MustMake(NameSymCellCenter)
	zs.SymCellLeft = sf.MustMake(NameSymCellLeft)
	zs.SymCellRight = sf.MustMake(NameSymCellRight)
	zs.SymCite = sf.MustMake(NameSymCite)
	zs.SymDescription = sf.MustMake(NameSymDescription)
	zs.SymEmbed = sf.MustMake(NameSymEmbed)
	zs.SymEmbedBLOB = sf.MustMake(NameSymEmbedBLOB)
	zs.SymEndnote = sf.MustMake(NameSymEndnote)
	zs.SymFormatEmph = sf.MustMake(NameSymFormatEmph)
	zs.SymFormatDelete = sf.MustMake(NameSymFormatDelete)
	zs.SymFormatInsert = sf.MustMake(NameSymFormatInsert)
	zs.SymFormatMark = sf.MustMake(NameSymFormatMark)
	zs.SymFormatQuote = sf.MustMake(NameSymFormatQuote)
	zs.SymFormatSpan = sf.MustMake(NameSymFormatSpan)
	zs.SymFormatSub = sf.MustMake(NameSymFormatSub)
	zs.SymFormatSuper = sf.MustMake(NameSymFormatSuper)
	zs.SymFormatStrong = sf.MustMake(NameSymFormatStrong)
	zs.SymHard = sf.MustMake(NameSymHard)
	zs.SymHeading = sf.MustMake(NameSymHeading)
	zs.SymLinkInvalid = sf.MustMake(NameSymLinkInvalid)
	zs.SymLinkZettel = sf.MustMake(NameSymLinkZettel)
	zs.SymLinkSelf = sf.MustMake(NameSymLinkSelf)
	zs.SymLinkFound = sf.MustMake(NameSymLinkFound)
	zs.SymLinkBroken = sf.MustMake(NameSymLinkBroken)
	zs.SymLinkHosted = sf.MustMake(NameSymLinkHosted)
	zs.SymLinkBased = sf.MustMake(NameSymLinkBased)
	zs.SymLinkQuery = sf.MustMake(NameSymLinkQuery)
	zs.SymLinkExternal = sf.MustMake(NameSymLinkExternal)
	zs.SymListOrdered = sf.MustMake(NameSymListOrdered)
	zs.SymListUnordered = sf.MustMake(NameSymListUnordered)
	zs.SymListQuote = sf.MustMake(NameSymListQuote)
	zs.SymLiteralProg = sf.MustMake(NameSymLiteralProg)
	zs.SymLiteralComment = sf.MustMake(NameSymLiteralComment)
	zs.SymLiteralHTML = sf.MustMake(NameSymLiteralHTML)
	zs.SymLiteralInput = sf.MustMake(NameSymLiteralInput)
	zs.SymLiteralMath = sf.MustMake(NameSymLiteralMath)
	zs.SymLiteralOutput = sf.MustMake(NameSymLiteralOutput)
	zs.SymLiteralZettel = sf.MustMake(NameSymLiteralZettel)
	zs.SymMark = sf.MustMake(NameSymMark)
	zs.SymPara = sf.MustMake(NameSymPara)
	zs.SymRegionBlock = sf.MustMake(NameSymRegionBlock)
	zs.SymRegionQuote = sf.MustMake(NameSymRegionQuote)
	zs.SymRegionVerse = sf.MustMake(NameSymRegionVerse)
	zs.SymSoft = sf.MustMake(NameSymSoft)
	zs.SymSpace = sf.MustMake(NameSymSpace)
	zs.SymTable = sf.MustMake(NameSymTable)
	zs.SymText = sf.MustMake(NameSymText)
	zs.SymThematic = sf.MustMake(NameSymThematic)
	zs.SymTransclude = sf.MustMake(NameSymTransclude)
	zs.SymUnknown = sf.MustMake(NameSymUnknown)
	zs.SymVerbatimComment = sf.MustMake(NameSymVerbatimComment)
	zs.SymVerbatimEval = sf.MustMake(NameSymVerbatimEval)
	zs.SymVerbatimHTML = sf.MustMake(NameSymVerbatimHTML)
	zs.SymVerbatimMath = sf.MustMake(NameSymVerbatimMath)
	zs.SymVerbatimProg = sf.MustMake(NameSymVerbatimProg)
	zs.SymVerbatimZettel = sf.MustMake(NameSymVerbatimZettel)

	// Constant symbols for reference states.
	zs.SymRefStateInvalid = sf.MustMake(NameSymRefStateInvalid)
	zs.SymRefStateZettel = sf.MustMake(NameSymRefStateZettel)
	zs.SymRefStateSelf = sf.MustMake(NameSymRefStateSelf)
	zs.SymRefStateFound = sf.MustMake(NameSymRefStateFound)
	zs.SymRefStateBroken = sf.MustMake(NameSymRefStateBroken)
	zs.SymRefStateHosted = sf.MustMake(NameSymRefStateHosted)
	zs.SymRefStateBased = sf.MustMake(NameSymRefStateBased)
	zs.SymRefStateQuery = sf.MustMake(NameSymRefStateQuery)
	zs.SymRefStateExternal = sf.MustMake(NameSymRefStateExternal)

	// Symbols for metadata types.
	zs.SymTypeCredential = sf.MustMake(NameSymTypeCredential)
	zs.SymTypeEmpty = sf.MustMake(NameSymTypeEmpty)
	zs.SymTypeID = sf.MustMake(NameSymTypeID)
	zs.SymTypeIDSet = sf.MustMake(NameSymTypeIDSet)
	zs.SymTypeNumber = sf.MustMake(NameSymTypeNumber)
	zs.SymTypeString = sf.MustMake(NameSymTypeString)
	zs.SymTypeTagSet = sf.MustMake(NameSymTypeTagSet)
	zs.SymTypeTimestamp = sf.MustMake(NameSymTypeTimestamp)
	zs.SymTypeURL = sf.MustMake(NameSymTypeURL)
	zs.SymTypeWord = sf.MustMake(NameSymTypeWord)
	zs.SymTypeWordSet = sf.MustMake(NameSymTypeWordSet)
	zs.SymTypeZettelmarkup = sf.MustMake(NameSymTypeZettelmarkup)
}

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

package sz_test

import (
	"strconv"
	"testing"

	"zettelstore.de/client.fossil/sz"
	"zettelstore.de/sx.fossil"
)

func BenchmarkInitZttlSyms(b *testing.B) {
	for j := 0; j < 20; j++ {
		b.Run("hint-"+strconv.Itoa(j), func(b *testing.B) {
			sf := sx.MakeMappedFactory(1 << j)
			for i := 0; i < b.N; i++ {
				var zs sz.ZettelSymbols
				zs.InitializeZettelSymbols(sf)
			}
		})
	}
}

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

package sz

import (
	"zettelstore.de/client.fossil/attrs"
	"zettelstore.de/sx.fossil"
)

// GetAttributes traverses a s-expression list and returns an attribute structure.
func GetAttributes(seq *sx.Pair) (result attrs.Attributes) {
	for elem := seq; elem != nil; elem = elem.Tail() {
		pair, isPair := sx.GetPair(elem.Car())
		if !isPair || pair == nil {
			continue
		}
		key := pair.Car()
		if !key.IsAtom() {
			continue
		}
		val := pair.Cdr()
		if tail, isTailPair := sx.GetPair(val); isTailPair {
			val = tail.Car()
		}
		if !val.IsAtom() {
			continue
		}
		result = result.Set(key.String(), val.String())
	}
	return result
}

// GetMetaContent returns the metadata and the content of a sz encoded zettel.
func GetMetaContent(zettel sx.Object) (Meta, *sx.Pair) {
	if pair, isPair := sx.GetPair(zettel); isPair {
		m := pair.Car()
		if s := pair.Tail(); s != nil {
			if content, isContentPair := sx.GetPair(s.Car()); isContentPair {
				return MakeMeta(m), content
			}
		}
		return MakeMeta(m), nil
	}
	return nil, nil
}

type Meta map[string]MetaValue
type MetaValue struct {
	Type  string
	Key   string
	Value sx.Object
}

func MakeMeta(obj sx.Object) Meta {
	if result := doMakeMeta(obj); len(result) > 0 {
		return result
	}
	return nil
}
func doMakeMeta(obj sx.Object) Meta {
	result := make(map[string]MetaValue)
	for {
		if sx.IsNil(obj) {
			return result
		}
		pair, isPair := sx.GetPair(obj)
		if !isPair {
			return result
		}
		if mv, ok2 := makeMetaValue(pair); ok2 {
			result[mv.Key] = mv
		}
		obj = pair.Cdr()
	}
}
func makeMetaValue(mnode *sx.Pair) (MetaValue, bool) {
	var result MetaValue
	mval, isPair := sx.GetPair(mnode.Car())
	if !isPair {
		return result, false
	}
	typeSym, isSymbol := sx.GetSymbol(mval.Car())
	if !isSymbol {
		return result, false
	}
	keyPair, isPair := sx.GetPair(mval.Cdr())
	if !isPair {
		return result, false
	}
	keyList, isPair := sx.GetPair(keyPair.Car())
	if !isPair {
		return result, false
	}
	quoteSym, isSymbol := sx.GetSymbol(keyList.Car())
	if !isSymbol || quoteSym.Name() != "quote" {
		return result, false
	}
	keySym, isSymbol := sx.GetSymbol(keyList.Tail().Car())
	if !isSymbol {
		return result, false
	}
	valPair, isPair := sx.GetPair(keyPair.Cdr())
	if !isPair {
		return result, false
	}
	result.Type = typeSym.Name()
	result.Key = keySym.Name()
	result.Value = valPair.Car()
	return result, true
}

func (m Meta) GetString(key string) string {
	if v, found := m[key]; found {
		return v.Value.String()
	}
	return ""
}

func (m Meta) GetPair(key string) *sx.Pair {
	if mv, found := m[key]; found {
		if pair, isPair := sx.GetPair(mv.Value); isPair {
			return pair
		}
	}
	return nil
}

// Package text provides types, constants and function to work with text output.
package text

import (
	"strings"

	"zettelstore.de/client.fossil/sz"
	"zettelstore.de/sx.fossil"
	"codeberg.org/t73fde/sxpf"
	"zettelstore.de/c/sexpr"
)

// Encoder is the structure to hold relevant data to execute the encoding.
type Encoder struct {
	sf sx.SymbolFactory
	sf sxpf.SymbolFactory
	sb strings.Builder

	symText  *sx.Symbol
	symSpace *sx.Symbol
	symSoft  *sx.Symbol
	symHard  *sx.Symbol
	symQuote *sx.Symbol
	symText  *sxpf.Symbol
	symSpace *sxpf.Symbol
	symSoft  *sxpf.Symbol
	symHard  *sxpf.Symbol
	symQuote *sxpf.Symbol
}

func NewEncoder(sf sx.SymbolFactory) *Encoder {
func NewEncoder(sf sxpf.SymbolFactory) *Encoder {
	if sf == nil {
		return nil
	}
	enc := &Encoder{
		sf:       sf,
		sb:       strings.Builder{},
		symText:  sf.MustMake(sz.NameSymText),
		symSpace: sf.MustMake(sz.NameSymSpace),
		symSoft:  sf.MustMake(sz.NameSymSoft),
		symHard:  sf.MustMake(sz.NameSymHard),
		symQuote: sf.MustMake(sx.QuoteName),
		symText:  sf.MustMake(sexpr.NameSymText),
		symSpace: sf.MustMake(sexpr.NameSymSpace),
		symSoft:  sf.MustMake(sexpr.NameSymSoft),
		symHard:  sf.MustMake(sexpr.NameSymHard),
		symQuote: sf.MustMake(sexpr.NameSymQuote),
	}
	return enc
}

func (enc *Encoder) Encode(lst *sx.Pair) string {
func (enc *Encoder) Encode(lst *sxpf.List) string {
	enc.executeList(lst)
	result := enc.sb.String()
	enc.sb.Reset()
	return result
}

// EvaluateInlineString returns the text content of the given inline list as a string.
func EvaluateInlineString(lst *sx.Pair) string {
	if sf := sx.FindSymbolFactory(lst); sf != nil {
func EvaluateInlineString(lst *sxpf.List) string {
	if sf := sxpf.FindSymbolFactory(lst); sf != nil {
		return NewEncoder(sf).Encode(lst)
	}
	return ""
}

func (enc *Encoder) executeList(lst *sx.Pair) {
func (enc *Encoder) executeList(lst *sxpf.List) {
	for elem := lst; elem != nil; elem = elem.Tail() {
		enc.execute(elem.Car())
	}
}
func (enc *Encoder) execute(obj sx.Object) {
	cmd, isPair := sx.GetPair(obj)
	if !isPair {
func (enc *Encoder) execute(obj sxpf.Object) {
	cmd, ok := obj.(*sxpf.List)
	if !ok {
		return
	}
	sym := cmd.Car()
	if sx.IsNil(sym) {
	if sxpf.IsNil(sym) {
		return
	}
	if sym.IsEqual(enc.symText) {
		args := cmd.Tail()
		if args == nil {
			return
		}
		if val, isString := sx.GetString(args.Car()); isString {
		if val, ok2 := args.Car().(sxpf.String); ok2 {
			enc.sb.WriteString(val.String())
		}
	} else if sym.IsEqual(enc.symSpace) || sym.IsEqual(enc.symSoft) {
		enc.sb.WriteByte(' ')
	} else if sym.IsEqual(enc.symHard) {
		enc.sb.WriteByte('\n')
	} else if !sym.IsEqual(enc.symQuote) {
		enc.executeList(cmd.Tail())
	}
}

package text_test

import (
	"strings"
	"testing"

	"zettelstore.de/client.fossil/text"
	"zettelstore.de/sx.fossil"
	"zettelstore.de/sx.fossil/sxreader"
	"codeberg.org/t73fde/sxpf"
	"codeberg.org/t73fde/sxpf/reader"
	"zettelstore.de/c/text"
)

func TestSzText(t *testing.T) {
func TestSexprText(t *testing.T) {
	testcases := []struct {
		src string
		exp string
	}{
		{"()", ""},
		{`(INLINE (TEXT "a"))`, "a"},
		{`(INLINE (SPACE "a"))`, " "},
	}
	for i, tc := range testcases {
		sval, err := sxreader.MakeReader(strings.NewReader(tc.src)).Read()
		sval, err := reader.MakeReader(strings.NewReader(tc.src)).Read()
		if err != nil {
			t.Error(err)
			continue
		}
		seq, isPair := sx.GetPair(sval)
		if !isPair {
		seq, ok := sval.(*sxpf.List)
		if !ok {
			t.Errorf("%d: not a list: %v", i, sval)
		}
		got := text.EvaluateInlineString(seq)
		if got != tc.exp {
			t.Errorf("%d: EncodeBlock(%q) == %q, but got %q", i, tc.src, tc.exp, got)
		}
	}
}

<title>Change Log</title>

<a name="0_17"></a>
<h2>Changes for Version 0.17.0 (pending)</h2>

<a name="0_16"></a>
<h2>Changes for Version 0.16.0 (2023-11-30)</h2>
  *  Refactor shtml transformator to support evaluating the language tree of a
     zettel AST. Its API has been changes, since evaluation is now top-down,
     where previous transformation was bottom.up.
  *  Add API call to retrieve role zettel.
  *  Added constants for role zettel and to mark text within zettelmarkup.

<a name="0_15"></a>
<h2>Changes for Version 0.15.0 (2023-10-26)</h2>
  *  Tag zettel: API, constant values
  *  Refactorings b/c Sx

<a name="0_14"></a>
<h2>Changes for Version 0.14.0 (2023-09-23)</h2>
  *  Remove support for JSON encoding

<a name="0_13"></a>
<h2>Changes for Version 0.13.0 (2023-08-07)</h2>
  *  API uses plain data or sx data, but no JSON encoded data.
  *  Dependency sx is now hosted on Fossil repository, same for this library.

<a name="0_12"></a>
<h2>Changes for Version 0.12.0 (2023-06-05)</h2>
<h2>Changes for Version 0.12.0 (pending)</h2>
  *  Rename "sexpr" to "sz".

<a name="0_11"></a>
<h2>Changes for Version 0.11.0 (2023-03-27)</h2>
  *  Remove all zjson related declarations.
  *  Generate HTML via SxHTML, not manually and direct.

<a name="0_10"></a>

<title>Home</title>

This repository contains Go client software to
access [https://zettelstore.de|Zettelstore] via its API.

<h3>Latest Release: 0.16.0 (2023-11-30)</h3>
  *  [./changes.wiki#0_16|Change summary]
  *  [/timeline?p=v0.16.0&bt=v0.15.0&y=ci|Check-ins for version 0.16.0],
     [/vdiff?to=v0.16.0&from=v0.15.0|content diff]
  *  [/timeline?df=v0.16.0&y=ci|Check-ins derived from the 0.16.0 release],
     [/vdiff?from=v0.16.0&to=trunk|content diff]
<h3>Latest Release: 0.11.0 (2023-03-27)</h3>
  *  [./changes.wiki#0_11|Change summary]
  *  [/timeline?p=v0.11.0&bt=v0.10.0&y=ci|Check-ins for version 0.11.0],
     [/vdiff?to=v0.11.0&from=v0.10.0|content diff]
  *  [/timeline?df=v0.11.0&y=ci|Check-ins derived from the 0.11.0 release],
     [/vdiff?from=v0.11.0&to=trunk|content diff]
  *  [/timeline?t=release|Timeline of all past releases]

<h3>Use instructions</h3>

If you want to import this library into your own [https://go.dev/|Go] software,
you must execute a <code>go get</code> command. Since Go treats non-standard
software and non-standard platforms quite badly, you must use some non-standard
commands.

First, you must install the version control system
[https://fossil-scm.org|Fossil], which is a superior solution compared to Git,
in too many use cases. It is just a single executable, nothing more. Make sure,
it is in your search path for commands.

How you can execute the following Go command to retrieve a given version of
this library:

<code>GOVCS=zettelstore.de:fossil go get -x
zettelstore.de/client.fossil@HASH</code>

where <code>HASH</code> is the hash value of the commit you want to use.

Go currently seems not to support software versions when the software is
managed by Fossil. This explains the need for the hash value. However, this
methods works and you can use the client software to access a Zettelstore.