package topdata

import (
	"fmt"
	"html"
	"os"
	"strconv"
	"strings"
	"unicode"

	"gopkg.in/yaml.v3"
)

type wikiTableDefinitionsDocument struct {
	Tables map[string]wikiTableDefinition `json:"tables" yaml:"tables"`
}

type wikiTableDefinition struct {
	Source  string              `json:"source" yaml:"source"`
	Class   string              `json:"class" yaml:"class"`
	When    string              `json:"when" yaml:"when"`
	Rows    wikiTableRowsConfig `json:"rows" yaml:"rows"`
	Columns []wikiTableColumn   `json:"columns" yaml:"columns"`
}

type wikiTableRowsConfig struct {
	Levels string `json:"levels" yaml:"levels"`
	When   string `json:"when" yaml:"when"`
}

type wikiTableColumn struct {
	Key             string            `json:"key" yaml:"key"`
	Label           string            `json:"label" yaml:"label"`
	Value           string            `json:"value" yaml:"value"`
	Empty           string            `json:"empty" yaml:"empty"`
	Class           string            `json:"class" yaml:"class"`
	HeaderClass     string            `json:"header_class" yaml:"header_class"`
	AllowWikiMarkup bool              `json:"allow_wiki_markup" yaml:"allow_wiki_markup"`
	When            string            `json:"when" yaml:"when"`
	Children        []wikiTableColumn `json:"children" yaml:"children"`
}

type wikiTableRenderContext struct {
	Page      wikiTemplatePage
	TableName string
	Path      string
}

func loadWikiTableDefinitions(path string) (map[string]wikiTableDefinition, error) {
	raw, err := os.ReadFile(path)
	if err != nil {
		if os.IsNotExist(err) {
			return map[string]wikiTableDefinition{}, nil
		}
		return nil, fmt.Errorf("read wiki table definitions %s: %w", path, err)
	}
	return parseWikiTableDefinitions(raw, path)
}

func parseWikiTableDefinitions(raw []byte, path string) (map[string]wikiTableDefinition, error) {
	var doc wikiTableDefinitionsDocument
	if err := yaml.Unmarshal(raw, &doc); err != nil {
		return nil, fmt.Errorf("parse wiki table definitions %s: %w", path, err)
	}
	if len(doc.Tables) == 0 {
		return map[string]wikiTableDefinition{}, nil
	}
	for name, def := range doc.Tables {
		if strings.TrimSpace(def.Source) == "" {
			return nil, fmt.Errorf("wiki table definitions %s: table %s missing source", path, name)
		}
		if len(def.Columns) == 0 {
			return nil, fmt.Errorf("wiki table definitions %s: table %s missing columns", path, name)
		}
		for _, col := range def.Columns {
			if err := validateWikiTableColumn(path, name, col); err != nil {
				return nil, err
			}
		}
	}
	return doc.Tables, nil
}

func validateWikiTableColumn(path, tableName string, col wikiTableColumn) error {
	if strings.TrimSpace(col.Key) == "" {
		return fmt.Errorf("wiki table definitions %s: table %s has column without key", path, tableName)
	}
	if strings.TrimSpace(col.Value) != "" && len(col.Children) > 0 {
		return fmt.Errorf("wiki table definitions %s: table %s column %s cannot have both value and children", path, tableName, col.Key)
	}
	for _, child := range col.Children {
		if err := validateWikiTableColumn(path, tableName, child); err != nil {
			return err
		}
	}
	return nil
}

func (ctx *wikiContext) renderConfiguredWikiTable(templatePath, tableName string, page wikiTemplatePage) (string, error) {
	def, ok := ctx.wikiTableDefinitions[tableName]
	if !ok {
		return "", fmt.Errorf("render wiki template %s for %s: missing table definition %q in %s", templatePath, page.PageID, tableName, ctx.wikiTablesPath)
	}
	renderCtx := wikiTableRenderContext{Page: page, TableName: tableName, Path: ctx.wikiTablesPath}
	if strings.TrimSpace(def.When) != "" {
		value, err := ctx.evalWikiTableTemplate(def.When, page.Row, renderCtx)
		if err != nil {
			return "", err
		}
		if !truthyWikiTableValue(value) {
			return "", nil
		}
	}
	rows, err := ctx.wikiTableSourceRows(def, page)
	if err != nil {
		return "", fmt.Errorf("render wiki table %s for %s: %w", tableName, page.PageID, err)
	}
	if strings.TrimSpace(def.Rows.When) != "" {
		filtered := rows[:0]
		for _, row := range rows {
			value, err := ctx.evalWikiTableTemplate(def.Rows.When, row, renderCtx)
			if err != nil {
				return "", fmt.Errorf("render wiki table %s for %s row condition %q: %w", tableName, page.PageID, def.Rows.When, err)
			}
			if truthyWikiTableValue(value) {
				filtered = append(filtered, row)
			}
		}
		rows = filtered
	}
	if len(rows) == 0 {
		return "", nil
	}
	columns := visibleWikiTableColumns(def.Columns, map[string]any{}, ctx, renderCtx)
	if len(columns) == 0 {
		return "", nil
	}
	headerRows, leaves := buildWikiTableHeaders(columns)
	if len(leaves) == 0 {
		return "", nil
	}
	var out strings.Builder
	class := strings.TrimSpace(def.Class)
	if class != "" {
		out.WriteString(`<table class="` + html.EscapeString(class) + `">`)
	} else {
		out.WriteString("<table>")
	}
	out.WriteString("\n  <thead>\n")
	for _, headerRow := range headerRows {
		out.WriteString("    <tr>")
		for _, cell := range headerRow {
			out.WriteString(cell)
		}
		out.WriteString("</tr>\n")
	}
	out.WriteString("  </thead>\n  <tbody>\n")
	for _, row := range rows {
		out.WriteString("    <tr>")
		for _, col := range leaves {
			cell, err := ctx.renderWikiTableCell(col, row, renderCtx)
			if err != nil {
				return "", err
			}
			out.WriteString(cell)
		}
		out.WriteString("</tr>\n")
	}
	out.WriteString("  </tbody>\n</table>")
	return out.String(), nil
}

func visibleWikiTableColumns(columns []wikiTableColumn, row map[string]any, ctx *wikiContext, renderCtx wikiTableRenderContext) []wikiTableColumn {
	out := []wikiTableColumn{}
	for _, col := range columns {
		if strings.TrimSpace(col.When) != "" {
			value, err := ctx.evalWikiTableTemplate(col.When, row, renderCtx)
			if err != nil || !truthyWikiTableValue(value) {
				continue
			}
		}
		if len(col.Children) > 0 {
			col.Children = visibleWikiTableColumns(col.Children, row, ctx, renderCtx)
			if len(col.Children) == 0 {
				continue
			}
		}
		out = append(out, col)
	}
	return out
}

type wikiTableHeaderCell struct {
	HTML string
}

func buildWikiTableHeaders(columns []wikiTableColumn) ([][]string, []wikiTableColumn) {
	hasGroups := false
	for _, col := range columns {
		if len(col.Children) > 0 {
			hasGroups = true
			break
		}
	}
	first := []string{}
	second := []string{}
	leaves := []wikiTableColumn{}
	for _, col := range columns {
		label := html.EscapeString(defaultStringValue(col.Label, col.Key))
		headerClass := attrClass(col.HeaderClass)
		if len(col.Children) == 0 {
			leaves = append(leaves, col)
			rowspan := ""
			if hasGroups {
				rowspan = ` rowspan="2"`
			}
			first = append(first, `<th scope="col"`+rowspan+headerClass+`>`+label+`</th>`)
			continue
		}
		childLeaves := leafWikiTableColumns(col.Children)
		first = append(first, `<th scope="colgroup" colspan="`+strconv.Itoa(len(childLeaves))+`"`+headerClass+`>`+label+`</th>`)
		for _, child := range col.Children {
			childLabel := html.EscapeString(defaultStringValue(child.Label, child.Key))
			second = append(second, `<th scope="col"`+attrClass(child.HeaderClass)+`>`+childLabel+`</th>`)
		}
		leaves = append(leaves, childLeaves...)
	}
	if hasGroups {
		return [][]string{first, second}, leaves
	}
	return [][]string{first}, leaves
}

func leafWikiTableColumns(columns []wikiTableColumn) []wikiTableColumn {
	out := []wikiTableColumn{}
	for _, col := range columns {
		if len(col.Children) == 0 {
			out = append(out, col)
			continue
		}
		out = append(out, leafWikiTableColumns(col.Children)...)
	}
	return out
}

func (ctx *wikiContext) renderWikiTableCell(col wikiTableColumn, row map[string]any, renderCtx wikiTableRenderContext) (string, error) {
	value, err := ctx.evalWikiTableTemplate(col.Value, row, renderCtx)
	if err != nil {
		return "", fmt.Errorf("render wiki table %s for %s column %s expression %q: %w", renderCtx.TableName, renderCtx.Page.PageID, col.Key, col.Value, err)
	}
	text := stringifyWikiTableValue(value)
	if strings.TrimSpace(text) == "" {
		text = col.Empty
	}
	if !col.AllowWikiMarkup {
		text = html.EscapeString(text)
	}
	return `<td` + attrClass(col.Class) + `>` + text + `</td>`, nil
}

func attrClass(class string) string {
	class = strings.TrimSpace(class)
	if class == "" {
		return ""
	}
	return ` class="` + html.EscapeString(class) + `"`
}

func defaultStringValue(value, fallback string) string {
	if strings.TrimSpace(value) != "" {
		return value
	}
	return fallback
}

func (ctx *wikiContext) wikiTableSourceRows(def wikiTableDefinition, page wikiTemplatePage) ([]map[string]any, error) {
	switch strings.TrimSpace(def.Source) {
	case "class_progression":
		if page.Category != "classes" {
			return nil, nil
		}
		return ctx.classProgressionRows(def, page.Row)
	case "class_feats":
		if page.Category != "classes" {
			return nil, nil
		}
		return ctx.classFeatRows(page.Row), nil
	case "spell_progression":
		if page.Category != "classes" {
			return nil, nil
		}
		if !hasSpellProgression(page.Row) {
			return nil, nil
		}
		return []map[string]any{}, nil
	case "class_summary":
		if page.Category != "classes" {
			return nil, nil
		}
		return ctx.classSummaryRows(page.Row), nil
	default:
		return nil, fmt.Errorf("unknown source %q", def.Source)
	}
}

func (ctx *wikiContext) classProgressionRows(def wikiTableDefinition, classRow map[string]any) ([]map[string]any, error) {
	start, end, err := parseLevelRange(def.Rows.Levels)
	if err != nil {
		return nil, err
	}
	saveRows := map[string]map[string]any{}
	if table := ctx.tableForValue(fieldValue(classRow, "SavingThrowTable"), ctx.classSaveTables); table != nil {
		for _, row := range table.Rows {
			level := stringValue(row, "Level")
			if level != "" {
				saveRows[level] = row
			}
		}
	}
	granted := map[int][]string{}
	if table := ctx.tableForValue(fieldValue(classRow, "FeatsTable"), ctx.classFeatTables); table != nil {
		for _, featRow := range table.Rows {
			level, err := strconv.Atoi(stringValue(featRow, "GrantedOnLevel"))
			if err != nil || level < start || level > end {
				continue
			}
			name := ctx.renderReference(fieldValue(featRow, "FeatIndex"), ctx.featIDToKey, ctx.resolveFeatName)
			if name != "" {
				granted[level] = append(granted[level], name)
			}
		}
	}
	bonusByLevel := map[int]string{}
	if table := ctx.tableForValue(fieldValue(classRow, "BonusFeatsTable"), ctx.classBonusTables); table != nil {
		for _, bonusRow := range table.Rows {
			level, err := asInt(fieldValue(bonusRow, "id"))
			if err != nil {
				continue
			}
			bonusByLevel[level] = stringValue(bonusRow, "Bonus")
		}
	}
	hitDie, _ := asInt(fieldValue(classRow, "HitDie"))
	out := []map[string]any{}
	for level := start; level <= end; level++ {
		row := cloneRowMap(classRow)
		row["Level"] = level
		row["BAB"] = formatSignedInt(classBABAtLevel(stringValue(classRow, "AttackBonusTable"), level))
		if saveRow := saveRows[strconv.Itoa(level)]; saveRow != nil {
			for key, value := range saveRow {
				row[key] = value
			}
		}
		row["GrantedFeats"] = granted[level]
		row["BonusFeat"] = bonusByLevel[level]
		row["HPMin"] = level
		if hitDie > 0 {
			row["HPMax"] = level * hitDie
		}
		row["Notes"] = ""
		row["HasSpellProgression"] = hasSpellProgression(classRow)
		out = append(out, row)
	}
	return out, nil
}

func parseLevelRange(raw string) (int, int, error) {
	raw = strings.TrimSpace(raw)
	if raw == "" {
		return 1, 20, nil
	}
	if !strings.Contains(raw, "-") {
		level, err := strconv.Atoi(raw)
		if err != nil || level < 1 {
			return 0, 0, fmt.Errorf("bad row range %q", raw)
		}
		return level, level, nil
	}
	left, right, _ := strings.Cut(raw, "-")
	start, err1 := strconv.Atoi(strings.TrimSpace(left))
	end, err2 := strconv.Atoi(strings.TrimSpace(right))
	if err1 != nil || err2 != nil || start < 1 || end < start {
		return 0, 0, fmt.Errorf("bad row range %q", raw)
	}
	return start, end, nil
}

func classBABAtLevel(table string, level int) int {
	switch strings.ToLower(strings.TrimSpace(table)) {
	case "cls_atk_1":
		return level
	case "cls_atk_2":
		return (level * 3) / 4
	case "cls_atk_3":
		return level / 2
	default:
		return 0
	}
}

func formatSignedInt(value int) string {
	if value > 0 {
		return "+" + strconv.Itoa(value)
	}
	return strconv.Itoa(value)
}

func (ctx *wikiContext) classFeatRows(classRow map[string]any) []map[string]any {
	table := ctx.tableForValue(fieldValue(classRow, "FeatsTable"), ctx.classFeatTables)
	if table == nil {
		return nil
	}
	out := []map[string]any{}
	for _, source := range table.Rows {
		row := cloneRowMap(source)
		key := resolveReferenceKey(fieldValue(source, "FeatIndex"), ctx.featIDToKey)
		if key == "" {
			key = resolveReferenceKey(fieldValue(source, "FeatIndex"), nil)
		}
		row["FeatKey"] = key
		row["FeatName"] = ctx.resolveFeatName(key)
		out = append(out, row)
	}
	return out
}

func (ctx *wikiContext) classSummaryRows(classRow map[string]any) []map[string]any {
	return []map[string]any{
		{"Label": "Hit Die", "Value": "d" + stringValue(classRow, "HitDie")},
		{"Label": "Skill Points", "Value": stringValue(classRow, "SkillPointBase")},
		{"Label": "Primary Ability", "Value": stringValue(classRow, "PrimaryAbil")},
	}
}

func hasSpellProgression(row map[string]any) bool {
	return stringValue(row, "SpellGainTable") != "" || stringValue(row, "SpellKnownTable") != ""
}

func (ctx *wikiContext) evalWikiTableTemplate(template string, row map[string]any, renderCtx wikiTableRenderContext) (any, error) {
	template = strings.TrimSpace(template)
	if strings.HasPrefix(template, "{{") && strings.HasSuffix(template, "}}") {
		expr := strings.TrimSpace(strings.TrimSuffix(strings.TrimPrefix(template, "{{"), "}}"))
		return evalWikiTableExpression(expr, row, ctx, renderCtx)
	}
	if strings.Contains(template, "{{") {
		return nil, fmt.Errorf("mixed literal/expression templates are not supported")
	}
	return template, nil
}

func evalWikiTableExpression(expr string, row map[string]any, ctx *wikiContext, renderCtx wikiTableRenderContext) (any, error) {
	parser := wikiExprParser{tokens: tokenizeWikiExpr(expr), row: row, ctx: ctx, renderCtx: renderCtx}
	value, err := parser.parseComparison()
	if err != nil {
		return nil, err
	}
	if parser.peek().kind != wikiExprEOF {
		return nil, fmt.Errorf("unexpected token %q", parser.peek().text)
	}
	return value, nil
}

type wikiExprTokenKind int

const (
	wikiExprEOF wikiExprTokenKind = iota
	wikiExprIdent
	wikiExprString
	wikiExprNumber
	wikiExprLParen
	wikiExprRParen
	wikiExprComma
	wikiExprPlus
	wikiExprEq
	wikiExprNE
	wikiExprGT
	wikiExprGE
	wikiExprLT
	wikiExprLE
	wikiExprAnd
	wikiExprOr
)

type wikiExprToken struct {
	kind wikiExprTokenKind
	text string
}

func tokenizeWikiExpr(expr string) []wikiExprToken {
	tokens := []wikiExprToken{}
	for i := 0; i < len(expr); {
		r := rune(expr[i])
		if unicode.IsSpace(r) {
			i++
			continue
		}
		switch expr[i] {
		case '(':
			tokens = append(tokens, wikiExprToken{kind: wikiExprLParen, text: "("})
			i++
		case ')':
			tokens = append(tokens, wikiExprToken{kind: wikiExprRParen, text: ")"})
			i++
		case ',':
			tokens = append(tokens, wikiExprToken{kind: wikiExprComma, text: ","})
			i++
		case '+':
			tokens = append(tokens, wikiExprToken{kind: wikiExprPlus, text: "+"})
			i++
		case '>':
			if i+1 < len(expr) && expr[i+1] == '=' {
				tokens = append(tokens, wikiExprToken{kind: wikiExprGE, text: ">="})
				i += 2
			} else {
				tokens = append(tokens, wikiExprToken{kind: wikiExprGT, text: ">"})
				i++
			}
		case '<':
			if i+1 < len(expr) && expr[i+1] == '=' {
				tokens = append(tokens, wikiExprToken{kind: wikiExprLE, text: "<="})
				i += 2
			} else {
				tokens = append(tokens, wikiExprToken{kind: wikiExprLT, text: "<"})
				i++
			}
		case '!':
			if i+1 < len(expr) && expr[i+1] == '=' {
				tokens = append(tokens, wikiExprToken{kind: wikiExprNE, text: "!="})
				i += 2
			} else {
				tokens = append(tokens, wikiExprToken{kind: wikiExprEOF, text: expr[i:]})
				return tokens
			}
		case '&':
			if i+1 < len(expr) && expr[i+1] == '&' {
				tokens = append(tokens, wikiExprToken{kind: wikiExprAnd, text: "&&"})
				i += 2
			} else {
				tokens = append(tokens, wikiExprToken{kind: wikiExprEOF, text: expr[i:]})
				return tokens
			}
		case '|':
			if i+1 < len(expr) && expr[i+1] == '|' {
				tokens = append(tokens, wikiExprToken{kind: wikiExprOr, text: "||"})
				i += 2
			} else {
				tokens = append(tokens, wikiExprToken{kind: wikiExprEOF, text: expr[i:]})
				return tokens
			}
		case '=':
			if i+1 < len(expr) && expr[i+1] == '=' {
				tokens = append(tokens, wikiExprToken{kind: wikiExprEq, text: "=="})
				i += 2
			} else {
				tokens = append(tokens, wikiExprToken{kind: wikiExprEOF, text: expr[i:]})
				return tokens
			}
		case '"':
			j := i + 1
			var b strings.Builder
			for ; j < len(expr); j++ {
				if expr[j] == '\\' && j+1 < len(expr) {
					j++
					b.WriteByte(expr[j])
					continue
				}
				if expr[j] == '"' {
					break
				}
				b.WriteByte(expr[j])
			}
			if j >= len(expr) {
				tokens = append(tokens, wikiExprToken{kind: wikiExprEOF, text: expr[i:]})
				return tokens
			}
			tokens = append(tokens, wikiExprToken{kind: wikiExprString, text: b.String()})
			i = j + 1
		default:
			if unicode.IsDigit(r) || expr[i] == '-' {
				j := i + 1
				for j < len(expr) && unicode.IsDigit(rune(expr[j])) {
					j++
				}
				tokens = append(tokens, wikiExprToken{kind: wikiExprNumber, text: expr[i:j]})
				i = j
				continue
			}
			if unicode.IsLetter(r) || expr[i] == '_' {
				j := i + 1
				for j < len(expr) {
					rr := rune(expr[j])
					if !unicode.IsLetter(rr) && !unicode.IsDigit(rr) && expr[j] != '_' && expr[j] != '.' {
						break
					}
					j++
				}
				tokens = append(tokens, wikiExprToken{kind: wikiExprIdent, text: expr[i:j]})
				i = j
				continue
			}
			tokens = append(tokens, wikiExprToken{kind: wikiExprEOF, text: expr[i:]})
			return tokens
		}
	}
	tokens = append(tokens, wikiExprToken{kind: wikiExprEOF})
	return tokens
}

type wikiExprParser struct {
	tokens             []wikiExprToken
	pos                int
	row                map[string]any
	ctx                *wikiContext
	renderCtx          wikiTableRenderContext
	allowMissingFields bool
}

func (p *wikiExprParser) peek() wikiExprToken {
	if p.pos >= len(p.tokens) {
		return wikiExprToken{kind: wikiExprEOF}
	}
	return p.tokens[p.pos]
}

func (p *wikiExprParser) take(kind wikiExprTokenKind) (wikiExprToken, bool) {
	token := p.peek()
	if token.kind != kind {
		return token, false
	}
	p.pos++
	return token, true
}

func (p *wikiExprParser) parseComparison() (any, error) {
	return p.parseOr()
}

func (p *wikiExprParser) parseOr() (any, error) {
	left, err := p.parseAnd()
	if err != nil {
		return nil, err
	}
	for p.peek().kind == wikiExprOr {
		p.pos++
		right, err := p.parseAnd()
		if err != nil {
			return nil, err
		}
		left = truthyWikiTableValue(left) || truthyWikiTableValue(right)
	}
	return left, nil
}

func (p *wikiExprParser) parseAnd() (any, error) {
	left, err := p.parseRelational()
	if err != nil {
		return nil, err
	}
	for p.peek().kind == wikiExprAnd {
		p.pos++
		right, err := p.parseRelational()
		if err != nil {
			return nil, err
		}
		left = truthyWikiTableValue(left) && truthyWikiTableValue(right)
	}
	return left, nil
}

func (p *wikiExprParser) parseRelational() (any, error) {
	left, err := p.parseConcat()
	if err != nil {
		return nil, err
	}
	switch p.peek().kind {
	case wikiExprEq, wikiExprNE, wikiExprGT, wikiExprGE, wikiExprLT, wikiExprLE:
		op := p.peek().kind
		p.pos++
		right, err := p.parseConcat()
		if err != nil {
			return nil, err
		}
		switch op {
		case wikiExprEq:
			return stringifyWikiTableValue(left) == stringifyWikiTableValue(right), nil
		case wikiExprNE:
			return stringifyWikiTableValue(left) != stringifyWikiTableValue(right), nil
		case wikiExprGT:
			return numericWikiTableValue(left) > numericWikiTableValue(right), nil
		case wikiExprGE:
			return numericWikiTableValue(left) >= numericWikiTableValue(right), nil
		case wikiExprLT:
			return numericWikiTableValue(left) < numericWikiTableValue(right), nil
		case wikiExprLE:
			return numericWikiTableValue(left) <= numericWikiTableValue(right), nil
		}
		return false, nil
	default:
		return left, nil
	}
}

func (p *wikiExprParser) parseConcat() (any, error) {
	left, err := p.parsePrimary()
	if err != nil {
		return nil, err
	}
	for p.peek().kind == wikiExprPlus {
		p.pos++
		right, err := p.parsePrimary()
		if err != nil {
			return nil, err
		}
		left = stringifyWikiTableValue(left) + stringifyWikiTableValue(right)
	}
	return left, nil
}

func (p *wikiExprParser) parsePrimary() (any, error) {
	token := p.peek()
	switch token.kind {
	case wikiExprString:
		p.pos++
		return token.text, nil
	case wikiExprNumber:
		p.pos++
		value, err := strconv.Atoi(token.text)
		if err != nil {
			return nil, fmt.Errorf("invalid number %q", token.text)
		}
		return value, nil
	case wikiExprIdent:
		p.pos++
		if p.peek().kind == wikiExprLParen {
			p.pos++
			args := []any{}
			if p.peek().kind != wikiExprRParen {
				for {
					arg, err := p.parseComparison()
					if err != nil {
						return nil, err
					}
					args = append(args, arg)
					if _, ok := p.take(wikiExprComma); !ok {
						break
					}
				}
			}
			if _, ok := p.take(wikiExprRParen); !ok {
				return nil, fmt.Errorf("missing closing parenthesis for %s", token.text)
			}
			return p.callHelper(token.text, args)
		}
		return p.resolveField(token.text)
	case wikiExprLParen:
		p.pos++
		value, err := p.parseComparison()
		if err != nil {
			return nil, err
		}
		if _, ok := p.take(wikiExprRParen); !ok {
			return nil, fmt.Errorf("missing closing parenthesis")
		}
		return value, nil
	default:
		return nil, fmt.Errorf("unexpected token %q", token.text)
	}
}

func (p *wikiExprParser) resolveField(name string) (any, error) {
	name = strings.TrimPrefix(name, "row.")
	if name == "HasSpellProgression" {
		return hasSpellProgression(p.renderCtx.Page.Row), nil
	}
	switch name {
	case "true":
		return true, nil
	case "false":
		return false, nil
	}
	if value, ok := lookupField(p.row, name); ok {
		return value, nil
	}
	if value, ok := lookupField(p.renderCtx.Page.Row, name); ok {
		return value, nil
	}
	if p.allowMissingFields {
		return nil, nil
	}
	return nil, fmt.Errorf("missing field %q", name)
}

func (p *wikiExprParser) callHelper(name string, args []any) (any, error) {
	switch name {
	case "ordinal":
		if len(args) != 1 {
			return nil, fmt.Errorf("ordinal expects 1 argument")
		}
		return ordinalWikiTableValue(numericWikiTableValue(args[0])), nil
	case "range":
		if len(args) != 2 {
			return nil, fmt.Errorf("range expects 2 arguments")
		}
		left := stringifyWikiTableValue(args[0])
		right := stringifyWikiTableValue(args[1])
		if left == "" || right == "" {
			return "", nil
		}
		return left + "-" + right, nil
	case "link":
		if len(args) == 1 {
			key := stringifyWikiTableValue(args[0])
			if p.ctx != nil && !p.ctx.canReferenceWikiKey(key) {
				return "", nil
			}
			if pageID := wikiPageIDForKey(key); pageID != "" {
				key = pageID
			}
			return "[[" + key + "]]", nil
		}
		if len(args) == 2 {
			key := stringifyWikiTableValue(args[0])
			label := stringifyWikiTableValue(args[1])
			if key == "" {
				return label, nil
			}
			if p.ctx != nil && !p.ctx.canReferenceWikiKey(key) {
				return "", nil
			}
			if pageID := wikiPageIDForKey(key); pageID != "" {
				key = pageID
			}
			return "[[" + key + "|" + label + "]]", nil
		}
		return nil, fmt.Errorf("link expects 1 or 2 arguments")
	case "if":
		if len(args) != 3 {
			return nil, fmt.Errorf("if expects 3 arguments")
		}
		if truthyWikiTableValue(args[0]) {
			return args[1], nil
		}
		return args[2], nil
	case "join":
		if len(args) != 2 {
			return nil, fmt.Errorf("join expects 2 arguments")
		}
		sep := stringifyWikiTableValue(args[1])
		switch typed := args[0].(type) {
		case []string:
			return strings.Join(typed, sep), nil
		case []any:
			parts := make([]string, 0, len(typed))
			for _, value := range typed {
				if text := stringifyWikiTableValue(value); text != "" {
					parts = append(parts, text)
				}
			}
			return strings.Join(parts, sep), nil
		default:
			return stringifyWikiTableValue(args[0]), nil
		}
	case "nonzero":
		if len(args) != 1 {
			return nil, fmt.Errorf("nonzero expects 1 argument")
		}
		if numericWikiTableValue(args[0]) == 0 {
			return "", nil
		}
		return args[0], nil
	case "eq":
		if len(args) != 2 {
			return nil, fmt.Errorf("eq expects 2 arguments")
		}
		return stringifyWikiTableValue(args[0]) == stringifyWikiTableValue(args[1]), nil
	case "field":
		if len(args) != 1 {
			return nil, fmt.Errorf("field expects 1 argument")
		}
		return p.resolveField(stringifyWikiTableValue(args[0]))
	case "default":
		if len(args) != 2 {
			return nil, fmt.Errorf("default expects 2 arguments")
		}
		if strings.TrimSpace(stringifyWikiTableValue(args[0])) == "" {
			return args[1], nil
		}
		return args[0], nil
	case "present":
		if len(args) != 1 {
			return nil, fmt.Errorf("present expects 1 argument")
		}
		return presentWikiValue(args[0]), nil
	case "all_present":
		if len(args) == 0 {
			return nil, fmt.Errorf("all_present expects at least 1 argument")
		}
		for _, value := range args {
			if !presentWikiValue(value) {
				return false, nil
			}
		}
		return true, nil
	case "any_present":
		if len(args) == 0 {
			return nil, fmt.Errorf("any_present expects at least 1 argument")
		}
		for _, value := range args {
			if presentWikiValue(value) {
				return true, nil
			}
		}
		return false, nil
	case "hidden_ref":
		if len(args) != 2 {
			return nil, fmt.Errorf("hidden_ref expects 2 arguments")
		}
		hidden, err := p.hiddenWikiReference(args[0], stringifyWikiTableValue(args[1]))
		if err != nil {
			return nil, err
		}
		return hidden, nil
	case "all_hidden_refs":
		if len(args) < 2 {
			return nil, fmt.Errorf("all_hidden_refs expects at least 2 arguments")
		}
		targetDataset := stringifyWikiTableValue(args[len(args)-1])
		checked := false
		for _, value := range args[:len(args)-1] {
			if !presentWikiValue(value) {
				continue
			}
			checked = true
			hidden, err := p.hiddenWikiReference(value, targetDataset)
			if err != nil {
				return nil, err
			}
			if !hidden {
				return false, nil
			}
		}
		return checked, nil
	default:
		return nil, fmt.Errorf("unknown helper %q", name)
	}
}

func (p *wikiExprParser) hiddenWikiReference(value any, targetDataset string) (bool, error) {
	targetDataset = strings.TrimSpace(targetDataset)
	if !isWikiVisibilityDataset(targetDataset) {
		return false, fmt.Errorf("unknown reference dataset %q", targetDataset)
	}
	if !presentWikiValue(value) {
		return false, nil
	}
	if p.ctx == nil {
		return false, nil
	}
	key := resolveReferenceKey(value, p.ctx.wikiIDMapForDataset(targetDataset))
	if key == "" {
		return true, nil
	}
	if !strings.HasPrefix(key, targetDataset+":") {
		return true, nil
	}
	return !p.ctx.canReferenceWikiKey(key), nil
}

func presentWikiValue(value any) bool {
	if isNullLike(value) {
		return false
	}
	if text, ok := value.(string); ok {
		return strings.TrimSpace(text) != ""
	}
	return value != nil
}

func ordinalWikiTableValue(value int) string {
	suffix := "th"
	if value%100 < 11 || value%100 > 13 {
		switch value % 10 {
		case 1:
			suffix = "st"
		case 2:
			suffix = "nd"
		case 3:
			suffix = "rd"
		}
	}
	return strconv.Itoa(value) + suffix
}

func stringifyWikiTableValue(value any) string {
	switch typed := value.(type) {
	case nil:
		return ""
	case string:
		if typed == nullValue {
			return ""
		}
		return typed
	case bool:
		if typed {
			return "true"
		}
		return ""
	case int:
		return strconv.Itoa(typed)
	case float64:
		return strconv.Itoa(int(typed))
	case []string:
		return strings.Join(typed, ", ")
	case []any:
		parts := make([]string, 0, len(typed))
		for _, value := range typed {
			if text := stringifyWikiTableValue(value); text != "" {
				parts = append(parts, text)
			}
		}
		return strings.Join(parts, ", ")
	default:
		return fmt.Sprint(typed)
	}
}

func numericWikiTableValue(value any) int {
	switch typed := value.(type) {
	case int:
		return typed
	case float64:
		return int(typed)
	case string:
		parsed, _ := strconv.Atoi(strings.TrimSpace(typed))
		return parsed
	default:
		parsed, _ := strconv.Atoi(strings.TrimSpace(stringifyWikiTableValue(value)))
		return parsed
	}
}

func truthyWikiTableValue(value any) bool {
	switch typed := value.(type) {
	case bool:
		return typed
	case nil:
		return false
	case string:
		trimmed := strings.TrimSpace(strings.ToLower(typed))
		return trimmed != "" && trimmed != "0" && trimmed != "false" && trimmed != nullValue
	case int:
		return typed != 0
	case float64:
		return typed != 0
	default:
		return strings.TrimSpace(stringifyWikiTableValue(value)) != ""
	}
}