package textfmt

import (
	"io"
	"time"
)

const (
	invalid = iota
	title
	paragraph
	list
	numberedList
	definitions
	numberedDefinitions
	table
	code
	syntax
)

type Txt struct {
	text         string
	link         string
	bold, italic bool
	cat          []Txt
}

type ListItem struct {
	text Txt
}

type DefinitionItem struct {
	name, value Txt
}

type TableCell struct {
	text Txt
}

type TableRow struct {
	cells  []TableCell
	header bool
}

type SyntaxItem struct {
	symbol    string
	multiple  bool
	required  bool
	optional  bool
	sequence  []SyntaxItem
	choice    []SyntaxItem
	topLevel  bool
	delimited bool
}

type Entry struct {
	typ         int
	text        Txt
	titleLevel  int
	items       []ListItem
	definitions []DefinitionItem
	rows        []TableRow
	syntax      SyntaxItem
	wrapWidth   int
	indent      int
	indentFirst int
	man struct{
		section int
		date time.Time
		version string
		category string
	}
}

type TitleInfo struct {
	section int
	date time.Time
	version string
	category string
}

type Document struct {
	entries []Entry
}

func Text(text string) Txt {
	return Txt{text: text}
}

func Link(label, uri string) Txt {
	return Txt{text: label, link: uri}
}

func Bold(t Txt) Txt {
	t.bold = true
	return t
}

func Italic(t Txt) Txt {
	t.italic = true
	return t
}

func Cat(t ...Txt) Txt {
	return Txt{cat: t}
}

func Title(level int, text string, manInfo ...TitleInfo) Entry {
	if level != 0 {
		return Entry{
			typ:        title,
			titleLevel: level,
			text:       Text(text),
		}
	}

	e := Entry{
		typ:        title,
		titleLevel: level,
		text:       Text(text),
	}

	for _, m := range manInfo {
		if m.section != 0 {
			e.man.section = m.section
		}

		if !m.date.IsZero() {
			e.man.date = m.date
		}

		if m.version != "" {
			e.man.version = m.version
		}

		if m.category != "" {
			e.man.category = m.category
		}
	}

	return e
}

func ManSection(s int) TitleInfo {
	return TitleInfo{section: s}
}

func ReleaseDate(d time.Time) TitleInfo {
	return TitleInfo{date: d}
}

func ReleaseVersion(v string) TitleInfo {
	return TitleInfo{version: v}
}

func ManCategory(c string) TitleInfo {
	return TitleInfo{category: c}
}

func Paragraph(t Txt) Entry {
	return Entry{typ: paragraph, text: t}
}

func Item(text Txt) ListItem {
	return ListItem{text: text}
}

func List(items ...ListItem) Entry {
	return Entry{typ: list, items: items}
}

func NumberedList(items ...ListItem) Entry {
	return Entry{typ: numberedList, items: items}
}

func Definition(name, value Txt) DefinitionItem {
	return DefinitionItem{name: name, value: value}
}

func DefinitionList(items ...DefinitionItem) Entry {
	return Entry{typ: definitions, definitions: items}
}

func NumberedDefinitionList(items ...DefinitionItem) Entry {
	return Entry{typ: numberedDefinitions, definitions: items}
}

func Cell(text Txt) TableCell {
	return TableCell{text: text}
}

func Header(cells ...TableCell) TableRow {
	return TableRow{cells: cells, header: true}
}

func Row(cells ...TableCell) TableRow {
	return TableRow{cells: cells}
}

func Table(rows ...TableRow) Entry {
	return Entry{typ: table, rows: rows}
}

func CodeBlock(codeBlock string) Entry {
	return Entry{typ: code, text: Text(codeBlock)}
}

func Symbol(text string) SyntaxItem {
	return SyntaxItem{symbol: text}
}

func OneOrMore(item SyntaxItem) SyntaxItem {
	item.required = true
	item.optional = false
	item.multiple = true
	return item
}

func ZeroOrMore(item SyntaxItem) SyntaxItem {
	item.required = false
	item.optional = true
	item.multiple = true
	return item
}

func Required(item SyntaxItem) SyntaxItem {
	item.required = true
	item.optional = false
	return item
}

func Optional(item SyntaxItem) SyntaxItem {
	item.required = false
	item.optional = true
	return item
}

func Sequence(items ...SyntaxItem) SyntaxItem {
	return SyntaxItem{sequence: items}
}

func Choice(items ...SyntaxItem) SyntaxItem {
	return SyntaxItem{choice: items}
}

func Syntax(items ...SyntaxItem) Entry {
	if len(items) == 1 {
		return Entry{typ: syntax, syntax: items[0]}
	}

	return Entry{typ: syntax, syntax: Sequence(items...)}
}

func Wrap(e Entry, width int) Entry {
	e.wrapWidth = width
	return e
}

// indentFirst is relative to indent
func Indent(e Entry, indent, indentFirst int) Entry {
	e.indent, e.indentFirst = indent, indentFirst
	return e
}

func Doc(e ...Entry) Document {
	return Document{entries: e}
}

func Teletype(out io.Writer, d Document) error {
	return renderTeletype(out, d)
}

// Runoff is an attempt to render roff format. It is primarily targeting man pages. While it may be possible to
// use for other purposes, the man macro will likely be required to render the output.
//
// Text is always wrapped, or as controlled by the roff processor, except for tables. The Wrap instrunction has
// no effect, except for tables.
func Runoff(out io.Writer, d Document) error {
	return renderRoff(out, d)
}

func Markdown(io.Writer, Document) error {
	return nil
}

func HTML(io.Writer, Document) error {
	// with the won HTML library
	return nil
}

func HTMLFragment(io.Writer, Document) error {
	// with the won HTML library
	return nil
}