package fzf

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

	"github.com/junegunn/fzf/src/algo"
	"github.com/junegunn/fzf/src/tui"
	"github.com/junegunn/fzf/src/util"

	"github.com/mattn/go-runewidth"
	"github.com/mattn/go-shellwords"
)

const usage = `usage: fzf [options]

  Search
    -x, --extended         Extended-search mode
                           (enabled by default; +x or --no-extended to disable)
    -e, --exact            Enable Exact-match
    -i                     Case-insensitive match (default: smart-case match)
    +i                     Case-sensitive match
    --scheme=SCHEME        Scoring scheme [default|path|history]
    --literal              Do not normalize latin script letters before matching
    -n, --nth=N[,..]       Comma-separated list of field index expressions
                           for limiting search scope. Each can be a non-zero
                           integer or a range expression ([BEGIN]..[END]).
    --with-nth=N[,..]      Transform the presentation of each line using
                           field index expressions
    -d, --delimiter=STR    Field delimiter regex (default: AWK-style)
    +s, --no-sort          Do not sort the result
    --tac                  Reverse the order of the input
    --disabled             Do not perform search
    --tiebreak=CRI[,..]    Comma-separated list of sort criteria to apply
                           when the scores are tied [length|chunk|begin|end|index]
                           (default: length)

  Interface
    -m, --multi[=MAX]      Enable multi-select with tab/shift-tab
    --no-mouse             Disable mouse
    --bind=KEYBINDS        Custom key bindings. Refer to the man page.
    --cycle                Enable cyclic scroll
    --keep-right           Keep the right end of the line visible on overflow
    --scroll-off=LINES     Number of screen lines to keep above or below when
                           scrolling to the top or to the bottom (default: 0)
    --no-hscroll           Disable horizontal scroll
    --hscroll-off=COLS     Number of screen columns to keep to the right of the
                           highlighted substring (default: 10)
    --filepath-word        Make word-wise movements respect path separators
    --jump-labels=CHARS    Label characters for jump and jump-accept

  Layout
    --height=[~]HEIGHT[%]  Display fzf window below the cursor with the given
                           height instead of using fullscreen.
                           If prefixed with '~', fzf will determine the height
                           according to the input size.
    --min-height=HEIGHT    Minimum height when --height is given in percent
                           (default: 10)
    --layout=LAYOUT        Choose layout: [default|reverse|reverse-list]
    --border[=STYLE]       Draw border around the finder
                           [rounded|sharp|horizontal|vertical|
                            top|bottom|left|right|none] (default: rounded)
    --border-label=LABEL   Label to print on the border
    --border-label-pos=COL Position of the border label
                           [POSITIVE_INTEGER: columns from left|
                            NEGATIVE_INTEGER: columns from right][:bottom]
                           (default: 0 or center)
    --margin=MARGIN        Screen margin (TRBL | TB,RL | T,RL,B | T,R,B,L)
    --padding=PADDING      Padding inside border (TRBL | TB,RL | T,RL,B | T,R,B,L)
    --info=STYLE           Finder info style [default|hidden|inline|inline:SEPARATOR]
    --separator=STR        String to form horizontal separator on info line
    --no-separator         Hide info line separator
    --scrollbar[=CHAR]     Scrollbar character
    --no-scrollbar         Hide scrollbar
    --prompt=STR           Input prompt (default: '> ')
    --pointer=STR          Pointer to the current line (default: '>')
    --marker=STR           Multi-select marker (default: '>')
    --header=STR           String to print as header
    --header-lines=N       The first N lines of the input are treated as header
    --header-first         Print header before the prompt line
    --ellipsis=STR         Ellipsis to show when line is truncated (default: '..')

  Display
    --ansi                 Enable processing of ANSI color codes
    --tabstop=SPACES       Number of spaces for a tab character (default: 8)
    --color=COLSPEC        Base scheme (dark|light|16|bw) and/or custom colors
    --no-bold              Do not use bold text

  History
    --history=FILE         History file
    --history-size=N       Maximum number of history entries (default: 1000)

  Preview
    --preview=COMMAND      Command to preview highlighted line ({})
    --preview-window=OPT   Preview window layout (default: right:50%)
                           [up|down|left|right][,SIZE[%]]
                           [,[no]wrap][,[no]cycle][,[no]follow][,[no]hidden]
                           [,border-BORDER_OPT]
                           [,+SCROLL[OFFSETS][/DENOM]][,~HEADER_LINES]
                           [,default][,<SIZE_THRESHOLD(ALTERNATIVE_LAYOUT)]
    --preview-label=LABEL
    --preview-label-pos=N  Same as --border-label and --border-label-pos,
                           but for preview window

  Scripting
    -q, --query=STR        Start the finder with the given query
    -1, --select-1         Automatically select the only match
    -0, --exit-0           Exit immediately when there's no match
    -f, --filter=STR       Filter mode. Do not start interactive finder.
    --print-query          Print query as the first line
    --expect=KEYS          Comma-separated list of keys to complete fzf
    --read0                Read input delimited by ASCII NUL characters
    --print0               Print output delimited by ASCII NUL characters
    --sync                 Synchronous search for multi-staged filtering
    --listen[=HTTP_PORT]   Start HTTP server to receive actions (POST /)
    --version              Display version information and exit

  Environment variables
    FZF_DEFAULT_COMMAND    Default command to use when input is tty
    FZF_DEFAULT_OPTS       Default options
                           (e.g. '--layout=reverse --inline-info')

`

const defaultInfoSep = " < "

// Case denotes case-sensitivity of search
type Case int

// Case-sensitivities
const (
	CaseSmart Case = iota
	CaseIgnore
	CaseRespect
)

// Sort criteria
type criterion int

const (
	byScore criterion = iota
	byChunk
	byLength
	byBegin
	byEnd
)

type heightSpec struct {
	size    float64
	percent bool
	auto    bool
}

type sizeSpec struct {
	size    float64
	percent bool
}

func defaultMargin() [4]sizeSpec {
	return [4]sizeSpec{}
}

type windowPosition int

const (
	posUp windowPosition = iota
	posDown
	posLeft
	posRight
)

type layoutType int

const (
	layoutDefault layoutType = iota
	layoutReverse
	layoutReverseList
)

type infoStyle int

const (
	infoDefault infoStyle = iota
	infoInline
	infoHidden
)

type labelOpts struct {
	label  string
	column int
	bottom bool
}

type previewOpts struct {
	command     string
	position    windowPosition
	size        sizeSpec
	scroll      string
	hidden      bool
	wrap        bool
	cycle       bool
	follow      bool
	border      tui.BorderShape
	headerLines int
	threshold   int
	alternative *previewOpts
}

func (o *previewOpts) Visible() bool {
	return o.size.size > 0 || o.alternative != nil && o.alternative.size.size > 0
}

func (o *previewOpts) Toggle() {
	o.hidden = !o.hidden
}

func parseLabelPosition(opts *labelOpts, arg string) {
	opts.column = 0
	opts.bottom = false
	for _, token := range splitRegexp.Split(strings.ToLower(arg), -1) {
		switch token {
		case "center":
			opts.column = 0
		case "bottom":
			opts.bottom = true
		case "top":
			opts.bottom = false
		default:
			opts.column = atoi(token)
		}
	}
}

func (a previewOpts) aboveOrBelow() bool {
	return a.size.size > 0 && (a.position == posUp || a.position == posDown)
}

func (a previewOpts) sameLayout(b previewOpts) bool {
	return a.size == b.size && a.position == b.position && a.border == b.border && a.hidden == b.hidden && a.threshold == b.threshold &&
		(a.alternative != nil && b.alternative != nil && a.alternative.sameLayout(*b.alternative) ||
			a.alternative == nil && b.alternative == nil)
}

func (a previewOpts) sameContentLayout(b previewOpts) bool {
	return a.wrap == b.wrap && a.headerLines == b.headerLines
}

func firstLine(s string) string {
	return strings.SplitN(s, "\n", 2)[0]
}

// Options stores the values of command-line options
type Options struct {
	Fuzzy        bool
	FuzzyAlgo    algo.Algo
	Scheme       string
	Extended     bool
	Phony        bool
	Case         Case
	Normalize    bool
	Nth          []Range
	WithNth      []Range
	Delimiter    Delimiter
	Sort         int
	Tac          bool
	Criteria     []criterion
	Multi        int
	Ansi         bool
	Mouse        bool
	Theme        *tui.ColorTheme
	Black        bool
	Bold         bool
	Height       heightSpec
	MinHeight    int
	Layout       layoutType
	Cycle        bool
	KeepRight    bool
	Hscroll      bool
	HscrollOff   int
	ScrollOff    int
	FileWord     bool
	InfoStyle    infoStyle
	InfoSep      string
	Separator    *string
	JumpLabels   string
	Prompt       string
	Pointer      string
	Marker       string
	Query        string
	Select1      bool
	Exit0        bool
	Filter       *string
	ToggleSort   bool
	Expect       map[tui.Event]string
	Keymap       map[tui.Event][]*action
	Preview      previewOpts
	PrintQuery   bool
	ReadZero     bool
	Printer      func(string)
	PrintSep     string
	Sync         bool
	History      *History
	Header       []string
	HeaderLines  int
	HeaderFirst  bool
	Ellipsis     string
	Scrollbar    *string
	Margin       [4]sizeSpec
	Padding      [4]sizeSpec
	BorderShape  tui.BorderShape
	BorderLabel  labelOpts
	PreviewLabel labelOpts
	Unicode      bool
	Tabstop      int
	ListenPort   *int
	ClearOnExit  bool
	Version      bool
}

func defaultPreviewOpts(command string) previewOpts {
	return previewOpts{command, posRight, sizeSpec{50, true}, "", false, false, false, false, tui.DefaultBorderShape, 0, 0, nil}
}

func defaultOptions() *Options {
	return &Options{
		Fuzzy:        true,
		FuzzyAlgo:    algo.FuzzyMatchV2,
		Scheme:       "default",
		Extended:     true,
		Phony:        false,
		Case:         CaseSmart,
		Normalize:    true,
		Nth:          make([]Range, 0),
		WithNth:      make([]Range, 0),
		Delimiter:    Delimiter{},
		Sort:         1000,
		Tac:          false,
		Criteria:     []criterion{byScore, byLength},
		Multi:        0,
		Ansi:         false,
		Mouse:        true,
		Theme:        tui.EmptyTheme(),
		Black:        false,
		Bold:         true,
		MinHeight:    10,
		Layout:       layoutDefault,
		Cycle:        false,
		KeepRight:    false,
		Hscroll:      true,
		HscrollOff:   10,
		ScrollOff:    0,
		FileWord:     false,
		InfoStyle:    infoDefault,
		Separator:    nil,
		JumpLabels:   defaultJumpLabels,
		Prompt:       "> ",
		Pointer:      ">",
		Marker:       ">",
		Query:        "",
		Select1:      false,
		Exit0:        false,
		Filter:       nil,
		ToggleSort:   false,
		Expect:       make(map[tui.Event]string),
		Keymap:       make(map[tui.Event][]*action),
		Preview:      defaultPreviewOpts(""),
		PrintQuery:   false,
		ReadZero:     false,
		Printer:      func(str string) { fmt.Println(str) },
		PrintSep:     "\n",
		Sync:         false,
		History:      nil,
		Header:       make([]string, 0),
		HeaderLines:  0,
		HeaderFirst:  false,
		Ellipsis:     "..",
		Scrollbar:    nil,
		Margin:       defaultMargin(),
		Padding:      defaultMargin(),
		Unicode:      true,
		Tabstop:      8,
		BorderLabel:  labelOpts{},
		PreviewLabel: labelOpts{},
		ClearOnExit:  true,
		Version:      false}
}

func help(code int) {
	os.Stdout.WriteString(usage)
	os.Exit(code)
}

func errorExit(msg string) {
	os.Stderr.WriteString(msg + "\n")
	os.Exit(exitError)
}

func optString(arg string, prefixes ...string) (bool, string) {
	for _, prefix := range prefixes {
		if strings.HasPrefix(arg, prefix) {
			return true, arg[len(prefix):]
		}
	}
	return false, ""
}

func nextString(args []string, i *int, message string) string {
	if len(args) > *i+1 {
		*i++
	} else {
		errorExit(message)
	}
	return args[*i]
}

func optionalNextString(args []string, i *int) (bool, string) {
	if len(args) > *i+1 && !strings.HasPrefix(args[*i+1], "-") && !strings.HasPrefix(args[*i+1], "+") {
		*i++
		return true, args[*i]
	}
	return false, ""
}

func atoi(str string) int {
	num, err := strconv.Atoi(str)
	if err != nil {
		errorExit("not a valid integer: " + str)
	}
	return num
}

func atof(str string) float64 {
	num, err := strconv.ParseFloat(str, 64)
	if err != nil {
		errorExit("not a valid number: " + str)
	}
	return num
}

func nextInt(args []string, i *int, message string) int {
	if len(args) > *i+1 {
		*i++
	} else {
		errorExit(message)
	}
	return atoi(args[*i])
}

func optionalNumeric(args []string, i *int, defaultValue int) int {
	if len(args) > *i+1 {
		if strings.IndexAny(args[*i+1], "0123456789") == 0 {
			*i++
			return atoi(args[*i])
		}
	}
	return defaultValue
}

func splitNth(str string) []Range {
	if match, _ := regexp.MatchString("^[0-9,-.]+$", str); !match {
		errorExit("invalid format: " + str)
	}

	tokens := strings.Split(str, ",")
	ranges := make([]Range, len(tokens))
	for idx, s := range tokens {
		r, ok := ParseRange(&s)
		if !ok {
			errorExit("invalid format: " + str)
		}
		ranges[idx] = r
	}
	return ranges
}

func delimiterRegexp(str string) Delimiter {
	// Special handling of \t
	str = strings.Replace(str, "\\t", "\t", -1)

	// 1. Pattern does not contain any special character
	if regexp.QuoteMeta(str) == str {
		return Delimiter{str: &str}
	}

	rx, e := regexp.Compile(str)
	// 2. Pattern is not a valid regular expression
	if e != nil {
		return Delimiter{str: &str}
	}

	// 3. Pattern as regular expression. Slow.
	return Delimiter{regex: rx}
}

func isAlphabet(char uint8) bool {
	return char >= 'a' && char <= 'z'
}

func isNumeric(char uint8) bool {
	return char >= '0' && char <= '9'
}

func parseAlgo(str string) algo.Algo {
	switch str {
	case "v1":
		return algo.FuzzyMatchV1
	case "v2":
		return algo.FuzzyMatchV2
	default:
		errorExit("invalid algorithm (expected: v1 or v2)")
	}
	return algo.FuzzyMatchV2
}

func processScheme(opts *Options) {
	if !algo.Init(opts.Scheme) {
		errorExit("invalid scoring scheme (expected: default|path|history)")
	}
	if opts.Scheme == "history" {
		opts.Criteria = []criterion{byScore}
	}
}

func parseBorder(str string, optional bool) tui.BorderShape {
	switch str {
	case "rounded":
		return tui.BorderRounded
	case "sharp":
		return tui.BorderSharp
	case "bold":
		return tui.BorderBold
	case "double":
		return tui.BorderDouble
	case "horizontal":
		return tui.BorderHorizontal
	case "vertical":
		return tui.BorderVertical
	case "top":
		return tui.BorderTop
	case "bottom":
		return tui.BorderBottom
	case "left":
		return tui.BorderLeft
	case "right":
		return tui.BorderRight
	case "none":
		return tui.BorderNone
	default:
		if optional && str == "" {
			return tui.DefaultBorderShape
		}
		errorExit("invalid border style (expected: rounded|sharp|bold|double|horizontal|vertical|top|bottom|left|right|none)")
	}
	return tui.BorderNone
}

func parseKeyChords(str string, message string) map[tui.Event]string {
	return parseKeyChordsImpl(str, message, errorExit)
}

func parseKeyChordsImpl(str string, message string, exit func(string)) map[tui.Event]string {
	if len(str) == 0 {
		exit(message)
		return nil
	}

	str = regexp.MustCompile("(?i)(alt-),").ReplaceAllString(str, "$1"+string([]rune{escapedComma}))
	tokens := strings.Split(str, ",")
	if str == "," || strings.HasPrefix(str, ",,") || strings.HasSuffix(str, ",,") || strings.Contains(str, ",,,") {
		tokens = append(tokens, ",")
	}

	chords := make(map[tui.Event]string)
	for _, key := range tokens {
		if len(key) == 0 {
			continue // ignore
		}
		key = strings.ReplaceAll(key, string([]rune{escapedComma}), ",")
		lkey := strings.ToLower(key)
		add := func(e tui.EventType) {
			chords[e.AsEvent()] = key
		}
		switch lkey {
		case "up":
			add(tui.Up)
		case "down":
			add(tui.Down)
		case "left":
			add(tui.Left)
		case "right":
			add(tui.Right)
		case "enter", "return":
			add(tui.CtrlM)
		case "space":
			chords[tui.Key(' ')] = key
		case "bspace", "bs":
			add(tui.BSpace)
		case "ctrl-space":
			add(tui.CtrlSpace)
		case "ctrl-^", "ctrl-6":
			add(tui.CtrlCaret)
		case "ctrl-/", "ctrl-_":
			add(tui.CtrlSlash)
		case "ctrl-\\":
			add(tui.CtrlBackSlash)
		case "ctrl-]":
			add(tui.CtrlRightBracket)
		case "change":
			add(tui.Change)
		case "backward-eof":
			add(tui.BackwardEOF)
		case "start":
			add(tui.Start)
		case "load":
			add(tui.Load)
		case "focus":
			add(tui.Focus)
		case "alt-enter", "alt-return":
			chords[tui.CtrlAltKey('m')] = key
		case "alt-space":
			chords[tui.AltKey(' ')] = key
		case "alt-bs", "alt-bspace":
			add(tui.AltBS)
		case "alt-up":
			add(tui.AltUp)
		case "alt-down":
			add(tui.AltDown)
		case "alt-left":
			add(tui.AltLeft)
		case "alt-right":
			add(tui.AltRight)
		case "tab":
			add(tui.Tab)
		case "btab", "shift-tab":
			add(tui.BTab)
		case "esc":
			add(tui.ESC)
		case "del":
			add(tui.Del)
		case "home":
			add(tui.Home)
		case "end":
			add(tui.End)
		case "insert":
			add(tui.Insert)
		case "pgup", "page-up":
			add(tui.PgUp)
		case "pgdn", "page-down":
			add(tui.PgDn)
		case "alt-shift-up", "shift-alt-up":
			add(tui.AltSUp)
		case "alt-shift-down", "shift-alt-down":
			add(tui.AltSDown)
		case "alt-shift-left", "shift-alt-left":
			add(tui.AltSLeft)
		case "alt-shift-right", "shift-alt-right":
			add(tui.AltSRight)
		case "shift-up":
			add(tui.SUp)
		case "shift-down":
			add(tui.SDown)
		case "shift-left":
			add(tui.SLeft)
		case "shift-right":
			add(tui.SRight)
		case "left-click":
			add(tui.LeftClick)
		case "right-click":
			add(tui.RightClick)
		case "double-click":
			add(tui.DoubleClick)
		case "f10":
			add(tui.F10)
		case "f11":
			add(tui.F11)
		case "f12":
			add(tui.F12)
		default:
			runes := []rune(key)
			if len(key) == 10 && strings.HasPrefix(lkey, "ctrl-alt-") && isAlphabet(lkey[9]) {
				chords[tui.CtrlAltKey(rune(key[9]))] = key
			} else if len(key) == 6 && strings.HasPrefix(lkey, "ctrl-") && isAlphabet(lkey[5]) {
				add(tui.EventType(tui.CtrlA.Int() + int(lkey[5]) - 'a'))
			} else if len(runes) == 5 && strings.HasPrefix(lkey, "alt-") {
				r := runes[4]
				switch r {
				case escapedColon:
					r = ':'
				case escapedComma:
					r = ','
				case escapedPlus:
					r = '+'
				}
				chords[tui.AltKey(r)] = key
			} else if len(key) == 2 && strings.HasPrefix(lkey, "f") && key[1] >= '1' && key[1] <= '9' {
				add(tui.EventType(tui.F1.Int() + int(key[1]) - '1'))
			} else if len(runes) == 1 {
				chords[tui.Key(runes[0])] = key
			} else {
				exit("unsupported key: " + key)
				return nil
			}
		}
	}
	return chords
}

func parseTiebreak(str string) []criterion {
	criteria := []criterion{byScore}
	hasIndex := false
	hasChunk := false
	hasLength := false
	hasBegin := false
	hasEnd := false
	check := func(notExpected *bool, name string) {
		if *notExpected {
			errorExit("duplicate sort criteria: " + name)
		}
		if hasIndex {
			errorExit("index should be the last criterion")
		}
		*notExpected = true
	}
	for _, str := range strings.Split(strings.ToLower(str), ",") {
		switch str {
		case "index":
			check(&hasIndex, "index")
		case "chunk":
			check(&hasChunk, "chunk")
			criteria = append(criteria, byChunk)
		case "length":
			check(&hasLength, "length")
			criteria = append(criteria, byLength)
		case "begin":
			check(&hasBegin, "begin")
			criteria = append(criteria, byBegin)
		case "end":
			check(&hasEnd, "end")
			criteria = append(criteria, byEnd)
		default:
			errorExit("invalid sort criterion: " + str)
		}
	}
	if len(criteria) > 4 {
		errorExit("at most 3 tiebreaks are allowed: " + str)
	}
	return criteria
}

func dupeTheme(theme *tui.ColorTheme) *tui.ColorTheme {
	dupe := *theme
	return &dupe
}

func parseTheme(defaultTheme *tui.ColorTheme, str string) *tui.ColorTheme {
	theme := dupeTheme(defaultTheme)
	rrggbb := regexp.MustCompile("^#[0-9a-fA-F]{6}$")
	for _, str := range strings.Split(strings.ToLower(str), ",") {
		switch str {
		case "dark":
			theme = dupeTheme(tui.Dark256)
		case "light":
			theme = dupeTheme(tui.Light256)
		case "16":
			theme = dupeTheme(tui.Default16)
		case "bw", "no":
			theme = tui.NoColorTheme()
		default:
			fail := func() {
				errorExit("invalid color specification: " + str)
			}
			// Color is disabled
			if theme == nil {
				continue
			}

			components := strings.Split(str, ":")
			if len(components) < 2 {
				fail()
			}

			mergeAttr := func(cattr *tui.ColorAttr) {
				for _, component := range components[1:] {
					switch component {
					case "regular":
						cattr.Attr = tui.AttrRegular
					case "bold", "strong":
						cattr.Attr |= tui.Bold
					case "dim":
						cattr.Attr |= tui.Dim
					case "italic":
						cattr.Attr |= tui.Italic
					case "underline":
						cattr.Attr |= tui.Underline
					case "blink":
						cattr.Attr |= tui.Blink
					case "reverse":
						cattr.Attr |= tui.Reverse
					case "strikethrough":
						cattr.Attr |= tui.StrikeThrough
					case "black":
						cattr.Color = tui.Color(0)
					case "red":
						cattr.Color = tui.Color(1)
					case "green":
						cattr.Color = tui.Color(2)
					case "yellow":
						cattr.Color = tui.Color(3)
					case "blue":
						cattr.Color = tui.Color(4)
					case "magenta":
						cattr.Color = tui.Color(5)
					case "cyan":
						cattr.Color = tui.Color(6)
					case "white":
						cattr.Color = tui.Color(7)
					case "bright-black", "gray", "grey":
						cattr.Color = tui.Color(8)
					case "bright-red":
						cattr.Color = tui.Color(9)
					case "bright-green":
						cattr.Color = tui.Color(10)
					case "bright-yellow":
						cattr.Color = tui.Color(11)
					case "bright-blue":
						cattr.Color = tui.Color(12)
					case "bright-magenta":
						cattr.Color = tui.Color(13)
					case "bright-cyan":
						cattr.Color = tui.Color(14)
					case "bright-white":
						cattr.Color = tui.Color(15)
					case "":
					default:
						if rrggbb.MatchString(component) {
							cattr.Color = tui.HexToColor(component)
						} else {
							ansi32, err := strconv.Atoi(component)
							if err != nil || ansi32 < -1 || ansi32 > 255 {
								fail()
							}
							cattr.Color = tui.Color(ansi32)
						}
					}
				}
			}
			switch components[0] {
			case "query", "input":
				mergeAttr(&theme.Input)
			case "disabled":
				mergeAttr(&theme.Disabled)
			case "fg":
				mergeAttr(&theme.Fg)
			case "bg":
				mergeAttr(&theme.Bg)
			case "preview-fg":
				mergeAttr(&theme.PreviewFg)
			case "preview-bg":
				mergeAttr(&theme.PreviewBg)
			case "fg+":
				mergeAttr(&theme.Current)
			case "bg+":
				mergeAttr(&theme.DarkBg)
			case "gutter":
				mergeAttr(&theme.Gutter)
			case "hl":
				mergeAttr(&theme.Match)
			case "hl+":
				mergeAttr(&theme.CurrentMatch)
			case "border":
				mergeAttr(&theme.Border)
			case "separator":
				mergeAttr(&theme.Separator)
			case "scrollbar":
				mergeAttr(&theme.Scrollbar)
			case "label":
				mergeAttr(&theme.BorderLabel)
			case "preview-label":
				mergeAttr(&theme.PreviewLabel)
			case "prompt":
				mergeAttr(&theme.Prompt)
			case "spinner":
				mergeAttr(&theme.Spinner)
			case "info":
				mergeAttr(&theme.Info)
			case "pointer":
				mergeAttr(&theme.Cursor)
			case "marker":
				mergeAttr(&theme.Selected)
			case "header":
				mergeAttr(&theme.Header)
			default:
				fail()
			}
		}
	}
	return theme
}

var (
	executeRegexp    *regexp.Regexp
	splitRegexp      *regexp.Regexp
	actionNameRegexp *regexp.Regexp
)

func firstKey(keymap map[tui.Event]string) tui.Event {
	for k := range keymap {
		return k
	}
	return tui.EventType(0).AsEvent()
}

const (
	escapedColon = 0
	escapedComma = 1
	escapedPlus  = 2
)

func init() {
	executeRegexp = regexp.MustCompile(
		`(?si)[:+](become|execute(?:-multi|-silent)?|reload(?:-sync)?|preview|(?:change|transform)-(?:query|prompt|border-label|preview-label)|change-preview-window|change-preview|(?:re|un)bind|pos|put)`)
	splitRegexp = regexp.MustCompile("[,:]+")
	actionNameRegexp = regexp.MustCompile("(?i)^[a-z-]+")
}

func maskActionContents(action string) string {
	masked := ""
Loop:
	for len(action) > 0 {
		loc := executeRegexp.FindStringIndex(action)
		if loc == nil {
			masked += action
			break
		}
		masked += action[:loc[1]]
		action = action[loc[1]:]
		if len(action) == 0 {
			break
		}
		cs := string(action[0])
		ce := ")"
		switch action[0] {
		case ':':
			masked += strings.Repeat(" ", len(action))
			break Loop
		case '(':
			ce = ")"
		case '{':
			ce = "}"
		case '[':
			ce = "]"
		case '<':
			ce = ">"
		case '~', '!', '@', '#', '$', '%', '^', '&', '*', ';', '/', '|':
			ce = string(cs)
		default:
			continue
		}
		cs = regexp.QuoteMeta(cs)
		ce = regexp.QuoteMeta(ce)

		// @$ or @+
		loc = regexp.MustCompile(fmt.Sprintf(`(?s)^%s.*?(%s[+,]|%s$)`, cs, ce, ce)).FindStringIndex(action)
		if loc == nil {
			masked += action
			break
		}
		// Keep + or , at the end
		lastChar := action[loc[1]-1]
		if lastChar == '+' || lastChar == ',' {
			loc[1]--
		}
		masked += strings.Repeat(" ", loc[1])
		action = action[loc[1]:]
	}
	masked = strings.Replace(masked, "::", string([]rune{escapedColon, ':'}), -1)
	masked = strings.Replace(masked, ",:", string([]rune{escapedComma, ':'}), -1)
	masked = strings.Replace(masked, "+:", string([]rune{escapedPlus, ':'}), -1)
	return masked
}

func parseSingleActionList(str string, exit func(string)) []*action {
	// We prepend a colon to satisfy executeRegexp and remove it later
	masked := maskActionContents(":" + str)[1:]
	return parseActionList(masked, str, []*action{}, false, exit)
}

func parseActionList(masked string, original string, prevActions []*action, putAllowed bool, exit func(string)) []*action {
	maskedStrings := strings.Split(masked, "+")
	originalStrings := make([]string, len(maskedStrings))
	idx := 0
	for i, maskedString := range maskedStrings {
		originalStrings[i] = original[idx : idx+len(maskedString)]
		idx += len(maskedString) + 1
	}
	actions := make([]*action, 0, len(maskedStrings))
	appendAction := func(types ...actionType) {
		actions = append(actions, toActions(types...)...)
	}
	prevSpec := ""
	for specIndex, spec := range originalStrings {
		spec = prevSpec + spec
		specLower := strings.ToLower(spec)
		switch specLower {
		case "ignore":
			appendAction(actIgnore)
		case "beginning-of-line":
			appendAction(actBeginningOfLine)
		case "abort":
			appendAction(actAbort)
		case "accept":
			appendAction(actAccept)
		case "accept-non-empty":
			appendAction(actAcceptNonEmpty)
		case "print-query":
			appendAction(actPrintQuery)
		case "refresh-preview":
			appendAction(actRefreshPreview)
		case "replace-query":
			appendAction(actReplaceQuery)
		case "backward-char":
			appendAction(actBackwardChar)
		case "backward-delete-char":
			appendAction(actBackwardDeleteChar)
		case "backward-delete-char/eof":
			appendAction(actBackwardDeleteCharEOF)
		case "backward-word":
			appendAction(actBackwardWord)
		case "clear-screen":
			appendAction(actClearScreen)
		case "delete-char":
			appendAction(actDeleteChar)
		case "delete-char/eof":
			appendAction(actDeleteCharEOF)
		case "deselect":
			appendAction(actDeselect)
		case "end-of-line":
			appendAction(actEndOfLine)
		case "cancel":
			appendAction(actCancel)
		case "clear-query":
			appendAction(actClearQuery)
		case "clear-selection":
			appendAction(actClearSelection)
		case "forward-char":
			appendAction(actForwardChar)
		case "forward-word":
			appendAction(actForwardWord)
		case "jump":
			appendAction(actJump)
		case "jump-accept":
			appendAction(actJumpAccept)
		case "kill-line":
			appendAction(actKillLine)
		case "kill-word":
			appendAction(actKillWord)
		case "unix-line-discard", "line-discard":
			appendAction(actUnixLineDiscard)
		case "unix-word-rubout", "word-rubout":
			appendAction(actUnixWordRubout)
		case "yank":
			appendAction(actYank)
		case "backward-kill-word":
			appendAction(actBackwardKillWord)
		case "toggle-down":
			appendAction(actToggle, actDown)
		case "toggle-up":
			appendAction(actToggle, actUp)
		case "toggle-in":
			appendAction(actToggleIn)
		case "toggle-out":
			appendAction(actToggleOut)
		case "toggle-all":
			appendAction(actToggleAll)
		case "toggle-search":
			appendAction(actToggleSearch)
		case "select":
			appendAction(actSelect)
		case "select-all":
			appendAction(actSelectAll)
		case "deselect-all":
			appendAction(actDeselectAll)
		case "close":
			appendAction(actClose)
		case "toggle":
			appendAction(actToggle)
		case "down":
			appendAction(actDown)
		case "up":
			appendAction(actUp)
		case "first", "top":
			appendAction(actFirst)
		case "last":
			appendAction(actLast)
		case "page-up":
			appendAction(actPageUp)
		case "page-down":
			appendAction(actPageDown)
		case "half-page-up":
			appendAction(actHalfPageUp)
		case "half-page-down":
			appendAction(actHalfPageDown)
		case "prev-history", "previous-history":
			appendAction(actPrevHistory)
		case "next-history":
			appendAction(actNextHistory)
		case "prev-selected":
			appendAction(actPrevSelected)
		case "next-selected":
			appendAction(actNextSelected)
		case "show-preview":
			appendAction(actShowPreview)
		case "hide-preview":
			appendAction(actHidePreview)
		case "toggle-preview":
			appendAction(actTogglePreview)
		case "toggle-preview-wrap":
			appendAction(actTogglePreviewWrap)
		case "toggle-sort":
			appendAction(actToggleSort)
		case "preview-top":
			appendAction(actPreviewTop)
		case "preview-bottom":
			appendAction(actPreviewBottom)
		case "preview-up":
			appendAction(actPreviewUp)
		case "preview-down":
			appendAction(actPreviewDown)
		case "preview-page-up":
			appendAction(actPreviewPageUp)
		case "preview-page-down":
			appendAction(actPreviewPageDown)
		case "preview-half-page-up":
			appendAction(actPreviewHalfPageUp)
		case "preview-half-page-down":
			appendAction(actPreviewHalfPageDown)
		case "enable-search":
			appendAction(actEnableSearch)
		case "disable-search":
			appendAction(actDisableSearch)
		case "put":
			if putAllowed {
				appendAction(actRune)
			} else {
				exit("unable to put non-printable character")
			}
		default:
			t := isExecuteAction(specLower)
			if t == actIgnore {
				if specIndex == 0 && specLower == "" {
					actions = append(prevActions, actions...)
				} else {
					exit("unknown action: " + spec)
				}
			} else {
				offset := len(actionNameRegexp.FindString(spec))
				var actionArg string
				if spec[offset] == ':' {
					if specIndex == len(originalStrings)-1 {
						actionArg = spec[offset+1:]
						actions = append(actions, &action{t: t, a: actionArg})
					} else {
						prevSpec = spec + "+"
						continue
					}
				} else {
					actionArg = spec[offset+1 : len(spec)-1]
					actions = append(actions, &action{t: t, a: actionArg})
				}
				switch t {
				case actBecome:
					if util.IsWindows() {
						exit("become action is not supported on Windows")
					}
				case actUnbind, actRebind:
					parseKeyChordsImpl(actionArg, spec[0:offset]+" target required", exit)
				case actChangePreviewWindow:
					opts := previewOpts{}
					for _, arg := range strings.Split(actionArg, "|") {
						// Make sure that each expression is valid
						parsePreviewWindowImpl(&opts, arg, exit)
					}
				}
			}
		}
		prevSpec = ""
	}
	return actions
}

func parseKeymap(keymap map[tui.Event][]*action, str string, exit func(string)) {
	masked := maskActionContents(str)
	idx := 0
	for _, pairStr := range strings.Split(masked, ",") {
		origPairStr := str[idx : idx+len(pairStr)]
		idx += len(pairStr) + 1

		pair := strings.SplitN(pairStr, ":", 2)
		if len(pair) < 2 {
			exit("bind action not specified: " + origPairStr)
		}
		var key tui.Event
		if len(pair[0]) == 1 && pair[0][0] == escapedColon {
			key = tui.Key(':')
		} else if len(pair[0]) == 1 && pair[0][0] == escapedComma {
			key = tui.Key(',')
		} else if len(pair[0]) == 1 && pair[0][0] == escapedPlus {
			key = tui.Key('+')
		} else {
			keys := parseKeyChordsImpl(pair[0], "key name required", exit)
			key = firstKey(keys)
		}
		putAllowed := key.Type == tui.Rune && unicode.IsGraphic(key.Char)
		keymap[key] = parseActionList(pair[1], origPairStr[len(pair[0])+1:], keymap[key], putAllowed, exit)
	}
}

func isExecuteAction(str string) actionType {
	masked := maskActionContents(":" + str)[1:]
	if masked == str {
		// Not masked
		return actIgnore
	}

	prefix := actionNameRegexp.FindString(str)
	switch prefix {
	case "become":
		return actBecome
	case "reload":
		return actReload
	case "reload-sync":
		return actReloadSync
	case "unbind":
		return actUnbind
	case "rebind":
		return actRebind
	case "preview":
		return actPreview
	case "change-border-label":
		return actChangeBorderLabel
	case "change-preview-label":
		return actChangePreviewLabel
	case "change-preview-window":
		return actChangePreviewWindow
	case "change-preview":
		return actChangePreview
	case "change-prompt":
		return actChangePrompt
	case "change-query":
		return actChangeQuery
	case "pos":
		return actPosition
	case "execute":
		return actExecute
	case "execute-silent":
		return actExecuteSilent
	case "execute-multi":
		return actExecuteMulti
	case "put":
		return actPut
	case "transform-border-label":
		return actTransformBorderLabel
	case "transform-preview-label":
		return actTransformPreviewLabel
	case "transform-prompt":
		return actTransformPrompt
	case "transform-query":
		return actTransformQuery
	}
	return actIgnore
}

func parseToggleSort(keymap map[tui.Event][]*action, str string) {
	keys := parseKeyChords(str, "key name required")
	if len(keys) != 1 {
		errorExit("multiple keys specified")
	}
	keymap[firstKey(keys)] = toActions(actToggleSort)
}

func strLines(str string) []string {
	return strings.Split(strings.TrimSuffix(str, "\n"), "\n")
}

func parseSize(str string, maxPercent float64, label string) sizeSpec {
	var val float64
	percent := strings.HasSuffix(str, "%")
	if percent {
		val = atof(str[:len(str)-1])
		if val < 0 {
			errorExit(label + " must be non-negative")
		}
		if val > maxPercent {
			errorExit(fmt.Sprintf("%s too large (max: %d%%)", label, int(maxPercent)))
		}
	} else {
		if strings.Contains(str, ".") {
			errorExit(label + " (without %) must be a non-negative integer")
		}

		val = float64(atoi(str))
		if val < 0 {
			errorExit(label + " must be non-negative")
		}
	}
	return sizeSpec{val, percent}
}

func parseHeight(str string) heightSpec {
	heightSpec := heightSpec{}
	if strings.HasPrefix(str, "~") {
		heightSpec.auto = true
		str = str[1:]
	}

	size := parseSize(str, 100, "height")
	heightSpec.size = size.size
	heightSpec.percent = size.percent
	return heightSpec
}

func parseLayout(str string) layoutType {
	switch str {
	case "default":
		return layoutDefault
	case "reverse":
		return layoutReverse
	case "reverse-list":
		return layoutReverseList
	default:
		errorExit("invalid layout (expected: default / reverse / reverse-list)")
	}
	return layoutDefault
}

func parseInfoStyle(str string) (infoStyle, string) {
	switch str {
	case "default":
		return infoDefault, ""
	case "inline":
		return infoInline, defaultInfoSep
	case "hidden":
		return infoHidden, ""
	default:
		prefix := "inline:"
		if strings.HasPrefix(str, prefix) {
			return infoInline, strings.ReplaceAll(str[len(prefix):], "\n", " ")
		}
		errorExit("invalid info style (expected: default|hidden|inline|inline:SEPARATOR)")
	}
	return infoDefault, ""
}

func parsePreviewWindow(opts *previewOpts, input string) {
	parsePreviewWindowImpl(opts, input, errorExit)
}

func parsePreviewWindowImpl(opts *previewOpts, input string, exit func(string)) {
	tokenRegex := regexp.MustCompile(`[:,]*(<([1-9][0-9]*)\(([^)<]+)\)|[^,:]+)`)
	sizeRegex := regexp.MustCompile("^[0-9]+%?$")
	offsetRegex := regexp.MustCompile(`^(\+{-?[0-9]+})?([+-][0-9]+)*(-?/[1-9][0-9]*)?$`)
	headerRegex := regexp.MustCompile("^~(0|[1-9][0-9]*)$")
	tokens := tokenRegex.FindAllStringSubmatch(input, -1)
	var alternative string
	for _, match := range tokens {
		if len(match[2]) > 0 {
			opts.threshold = atoi(match[2])
			alternative = match[3]
			continue
		}
		token := match[1]
		switch token {
		case "":
		case "default":
			*opts = defaultPreviewOpts(opts.command)
		case "hidden":
			opts.hidden = true
		case "nohidden":
			opts.hidden = false
		case "wrap":
			opts.wrap = true
		case "nowrap":
			opts.wrap = false
		case "cycle":
			opts.cycle = true
		case "nocycle":
			opts.cycle = false
		case "up", "top":
			opts.position = posUp
		case "down", "bottom":
			opts.position = posDown
		case "left":
			opts.position = posLeft
		case "right":
			opts.position = posRight
		case "rounded", "border", "border-rounded":
			opts.border = tui.BorderRounded
		case "sharp", "border-sharp":
			opts.border = tui.BorderSharp
		case "border-bold":
			opts.border = tui.BorderBold
		case "border-double":
			opts.border = tui.BorderDouble
		case "noborder", "border-none":
			opts.border = tui.BorderNone
		case "border-horizontal":
			opts.border = tui.BorderHorizontal
		case "border-vertical":
			opts.border = tui.BorderVertical
		case "border-up", "border-top":
			opts.border = tui.BorderTop
		case "border-down", "border-bottom":
			opts.border = tui.BorderBottom
		case "border-left":
			opts.border = tui.BorderLeft
		case "border-right":
			opts.border = tui.BorderRight
		case "follow":
			opts.follow = true
		case "nofollow":
			opts.follow = false
		default:
			if headerRegex.MatchString(token) {
				opts.headerLines = atoi(token[1:])
			} else if sizeRegex.MatchString(token) {
				opts.size = parseSize(token, 99, "window size")
			} else if offsetRegex.MatchString(token) {
				opts.scroll = token
			} else {
				exit("invalid preview window option: " + token)
				return
			}
		}
	}
	if len(alternative) > 0 {
		alternativeOpts := *opts
		opts.alternative = &alternativeOpts
		opts.alternative.hidden = false
		opts.alternative.alternative = nil
		parsePreviewWindowImpl(opts.alternative, alternative, exit)
	}
}

func parseMargin(opt string, margin string) [4]sizeSpec {
	margins := strings.Split(margin, ",")
	checked := func(str string) sizeSpec {
		return parseSize(str, 49, opt)
	}
	switch len(margins) {
	case 1:
		m := checked(margins[0])
		return [4]sizeSpec{m, m, m, m}
	case 2:
		tb := checked(margins[0])
		rl := checked(margins[1])
		return [4]sizeSpec{tb, rl, tb, rl}
	case 3:
		t := checked(margins[0])
		rl := checked(margins[1])
		b := checked(margins[2])
		return [4]sizeSpec{t, rl, b, rl}
	case 4:
		return [4]sizeSpec{
			checked(margins[0]), checked(margins[1]),
			checked(margins[2]), checked(margins[3])}
	default:
		errorExit("invalid " + opt + ": " + margin)
	}
	return defaultMargin()
}

func parseOptions(opts *Options, allArgs []string) {
	var historyMax int
	if opts.History == nil {
		historyMax = defaultHistoryMax
	} else {
		historyMax = opts.History.maxSize
	}
	setHistory := func(path string) {
		h, e := NewHistory(path, historyMax)
		if e != nil {
			errorExit(e.Error())
		}
		opts.History = h
	}
	setHistoryMax := func(max int) {
		historyMax = max
		if historyMax < 1 {
			errorExit("history max must be a positive integer")
		}
		if opts.History != nil {
			opts.History.maxSize = historyMax
		}
	}
	validateJumpLabels := false
	validatePointer := false
	validateMarker := false
	for i := 0; i < len(allArgs); i++ {
		arg := allArgs[i]
		switch arg {
		case "-h", "--help":
			help(exitOk)
		case "-x", "--extended":
			opts.Extended = true
		case "-e", "--exact":
			opts.Fuzzy = false
		case "--extended-exact":
			// Note that we now don't have --no-extended-exact
			opts.Fuzzy = false
			opts.Extended = true
		case "+x", "--no-extended":
			opts.Extended = false
		case "+e", "--no-exact":
			opts.Fuzzy = true
		case "-q", "--query":
			opts.Query = nextString(allArgs, &i, "query string required")
		case "-f", "--filter":
			filter := nextString(allArgs, &i, "query string required")
			opts.Filter = &filter
		case "--literal":
			opts.Normalize = false
		case "--no-literal":
			opts.Normalize = true
		case "--algo":
			opts.FuzzyAlgo = parseAlgo(nextString(allArgs, &i, "algorithm required (v1|v2)"))
		case "--scheme":
			opts.Scheme = strings.ToLower(nextString(allArgs, &i, "scoring scheme required (default|path|history)"))
		case "--expect":
			for k, v := range parseKeyChords(nextString(allArgs, &i, "key names required"), "key names required") {
				opts.Expect[k] = v
			}
		case "--no-expect":
			opts.Expect = make(map[tui.Event]string)
		case "--enabled", "--no-phony":
			opts.Phony = false
		case "--disabled", "--phony":
			opts.Phony = true
		case "--tiebreak":
			opts.Criteria = parseTiebreak(nextString(allArgs, &i, "sort criterion required"))
		case "--bind":
			parseKeymap(opts.Keymap, nextString(allArgs, &i, "bind expression required"), errorExit)
		case "--color":
			_, spec := optionalNextString(allArgs, &i)
			if len(spec) == 0 {
				opts.Theme = tui.EmptyTheme()
			} else {
				opts.Theme = parseTheme(opts.Theme, spec)
			}
		case "--toggle-sort":
			parseToggleSort(opts.Keymap, nextString(allArgs, &i, "key name required"))
		case "-d", "--delimiter":
			opts.Delimiter = delimiterRegexp(nextString(allArgs, &i, "delimiter required"))
		case "-n", "--nth":
			opts.Nth = splitNth(nextString(allArgs, &i, "nth expression required"))
		case "--with-nth":
			opts.WithNth = splitNth(nextString(allArgs, &i, "nth expression required"))
		case "-s", "--sort":
			opts.Sort = optionalNumeric(allArgs, &i, 1)
		case "+s", "--no-sort":
			opts.Sort = 0
		case "--tac":
			opts.Tac = true
		case "--no-tac":
			opts.Tac = false
		case "-i":
			opts.Case = CaseIgnore
		case "+i":
			opts.Case = CaseRespect
		case "-m", "--multi":
			opts.Multi = optionalNumeric(allArgs, &i, maxMulti)
		case "+m", "--no-multi":
			opts.Multi = 0
		case "--ansi":
			opts.Ansi = true
		case "--no-ansi":
			opts.Ansi = false
		case "--no-mouse":
			opts.Mouse = false
		case "+c", "--no-color":
			opts.Theme = tui.NoColorTheme()
		case "+2", "--no-256":
			opts.Theme = tui.Default16
		case "--black":
			opts.Black = true
		case "--no-black":
			opts.Black = false
		case "--bold":
			opts.Bold = true
		case "--no-bold":
			opts.Bold = false
		case "--layout":
			opts.Layout = parseLayout(
				nextString(allArgs, &i, "layout required (default / reverse / reverse-list)"))
		case "--reverse":
			opts.Layout = layoutReverse
		case "--no-reverse":
			opts.Layout = layoutDefault
		case "--cycle":
			opts.Cycle = true
		case "--no-cycle":
			opts.Cycle = false
		case "--keep-right":
			opts.KeepRight = true
		case "--no-keep-right":
			opts.KeepRight = false
		case "--hscroll":
			opts.Hscroll = true
		case "--no-hscroll":
			opts.Hscroll = false
		case "--hscroll-off":
			opts.HscrollOff = nextInt(allArgs, &i, "hscroll offset required")
		case "--scroll-off":
			opts.ScrollOff = nextInt(allArgs, &i, "scroll offset required")
		case "--filepath-word":
			opts.FileWord = true
		case "--no-filepath-word":
			opts.FileWord = false
		case "--info":
			opts.InfoStyle, opts.InfoSep = parseInfoStyle(
				nextString(allArgs, &i, "info style required"))
		case "--no-info":
			opts.InfoStyle = infoHidden
		case "--inline-info":
			opts.InfoStyle = infoInline
			opts.InfoSep = defaultInfoSep
		case "--no-inline-info":
			opts.InfoStyle = infoDefault
		case "--separator":
			separator := nextString(allArgs, &i, "separator character required")
			opts.Separator = &separator
		case "--no-separator":
			nosep := ""
			opts.Separator = &nosep
		case "--scrollbar":
			given, bar := optionalNextString(allArgs, &i)
			if given {
				opts.Scrollbar = &bar
			} else {
				opts.Scrollbar = nil
			}
		case "--no-scrollbar":
			noBar := ""
			opts.Scrollbar = &noBar
		case "--jump-labels":
			opts.JumpLabels = nextString(allArgs, &i, "label characters required")
			validateJumpLabels = true
		case "-1", "--select-1":
			opts.Select1 = true
		case "+1", "--no-select-1":
			opts.Select1 = false
		case "-0", "--exit-0":
			opts.Exit0 = true
		case "+0", "--no-exit-0":
			opts.Exit0 = false
		case "--read0":
			opts.ReadZero = true
		case "--no-read0":
			opts.ReadZero = false
		case "--print0":
			opts.Printer = func(str string) { fmt.Print(str, "\x00") }
			opts.PrintSep = "\x00"
		case "--no-print0":
			opts.Printer = func(str string) { fmt.Println(str) }
			opts.PrintSep = "\n"
		case "--print-query":
			opts.PrintQuery = true
		case "--no-print-query":
			opts.PrintQuery = false
		case "--prompt":
			opts.Prompt = nextString(allArgs, &i, "prompt string required")
		case "--pointer":
			opts.Pointer = firstLine(nextString(allArgs, &i, "pointer sign string required"))
			validatePointer = true
		case "--marker":
			opts.Marker = firstLine(nextString(allArgs, &i, "selected sign string required"))
			validateMarker = true
		case "--sync":
			opts.Sync = true
		case "--no-sync":
			opts.Sync = false
		case "--async":
			opts.Sync = false
		case "--no-history":
			opts.History = nil
		case "--history":
			setHistory(nextString(allArgs, &i, "history file path required"))
		case "--history-size":
			setHistoryMax(nextInt(allArgs, &i, "history max size required"))
		case "--no-header":
			opts.Header = []string{}
		case "--no-header-lines":
			opts.HeaderLines = 0
		case "--header":
			opts.Header = strLines(nextString(allArgs, &i, "header string required"))
		case "--header-lines":
			opts.HeaderLines = atoi(
				nextString(allArgs, &i, "number of header lines required"))
		case "--header-first":
			opts.HeaderFirst = true
		case "--no-header-first":
			opts.HeaderFirst = false
		case "--ellipsis":
			opts.Ellipsis = nextString(allArgs, &i, "ellipsis string required")
		case "--preview":
			opts.Preview.command = nextString(allArgs, &i, "preview command required")
		case "--no-preview":
			opts.Preview.command = ""
		case "--preview-window":
			parsePreviewWindow(&opts.Preview,
				nextString(allArgs, &i, "preview window layout required: [up|down|left|right][,SIZE[%]][,border-BORDER_OPT][,wrap][,cycle][,hidden][,+SCROLL[OFFSETS][/DENOM]][,~HEADER_LINES][,default]"))
		case "--height":
			opts.Height = parseHeight(nextString(allArgs, &i, "height required: [~]HEIGHT[%]"))
		case "--min-height":
			opts.MinHeight = nextInt(allArgs, &i, "height required: HEIGHT")
		case "--no-height":
			opts.Height = heightSpec{}
		case "--no-margin":
			opts.Margin = defaultMargin()
		case "--no-padding":
			opts.Padding = defaultMargin()
		case "--no-border":
			opts.BorderShape = tui.BorderNone
		case "--border":
			hasArg, arg := optionalNextString(allArgs, &i)
			opts.BorderShape = parseBorder(arg, !hasArg)
		case "--no-border-label":
			opts.BorderLabel.label = ""
		case "--border-label":
			opts.BorderLabel.label = nextString(allArgs, &i, "label required")
		case "--border-label-pos":
			pos := nextString(allArgs, &i, "label position required (positive or negative integer or 'center')")
			parseLabelPosition(&opts.BorderLabel, pos)
		case "--no-preview-label":
			opts.PreviewLabel.label = ""
		case "--preview-label":
			opts.PreviewLabel.label = nextString(allArgs, &i, "preview label required")
		case "--preview-label-pos":
			pos := nextString(allArgs, &i, "preview label position required (positive or negative integer or 'center')")
			parseLabelPosition(&opts.PreviewLabel, pos)
		case "--no-unicode":
			opts.Unicode = false
		case "--unicode":
			opts.Unicode = true
		case "--margin":
			opts.Margin = parseMargin(
				"margin",
				nextString(allArgs, &i, "margin required (TRBL / TB,RL / T,RL,B / T,R,B,L)"))
		case "--padding":
			opts.Padding = parseMargin(
				"padding",
				nextString(allArgs, &i, "padding required (TRBL / TB,RL / T,RL,B / T,R,B,L)"))
		case "--tabstop":
			opts.Tabstop = nextInt(allArgs, &i, "tab stop required")
		case "--listen":
			port := optionalNumeric(allArgs, &i, 0)
			opts.ListenPort = &port
		case "--no-listen":
			opts.ListenPort = nil
		case "--clear":
			opts.ClearOnExit = true
		case "--no-clear":
			opts.ClearOnExit = false
		case "--version":
			opts.Version = true
		case "--":
			// Ignored
		default:
			if match, value := optString(arg, "--algo="); match {
				opts.FuzzyAlgo = parseAlgo(value)
			} else if match, value := optString(arg, "--scheme="); match {
				opts.Scheme = strings.ToLower(value)
			} else if match, value := optString(arg, "-q", "--query="); match {
				opts.Query = value
			} else if match, value := optString(arg, "-f", "--filter="); match {
				opts.Filter = &value
			} else if match, value := optString(arg, "-d", "--delimiter="); match {
				opts.Delimiter = delimiterRegexp(value)
			} else if match, value := optString(arg, "--border="); match {
				opts.BorderShape = parseBorder(value, false)
			} else if match, value := optString(arg, "--border-label="); match {
				opts.BorderLabel.label = value
			} else if match, value := optString(arg, "--border-label-pos="); match {
				parseLabelPosition(&opts.BorderLabel, value)
			} else if match, value := optString(arg, "--preview-label="); match {
				opts.PreviewLabel.label = value
			} else if match, value := optString(arg, "--preview-label-pos="); match {
				parseLabelPosition(&opts.PreviewLabel, value)
			} else if match, value := optString(arg, "--prompt="); match {
				opts.Prompt = value
			} else if match, value := optString(arg, "--pointer="); match {
				opts.Pointer = firstLine(value)
				validatePointer = true
			} else if match, value := optString(arg, "--marker="); match {
				opts.Marker = firstLine(value)
				validateMarker = true
			} else if match, value := optString(arg, "-n", "--nth="); match {
				opts.Nth = splitNth(value)
			} else if match, value := optString(arg, "--with-nth="); match {
				opts.WithNth = splitNth(value)
			} else if match, _ := optString(arg, "-s", "--sort="); match {
				opts.Sort = 1 // Don't care
			} else if match, value := optString(arg, "-m", "--multi="); match {
				opts.Multi = atoi(value)
			} else if match, value := optString(arg, "--height="); match {
				opts.Height = parseHeight(value)
			} else if match, value := optString(arg, "--min-height="); match {
				opts.MinHeight = atoi(value)
			} else if match, value := optString(arg, "--layout="); match {
				opts.Layout = parseLayout(value)
			} else if match, value := optString(arg, "--info="); match {
				opts.InfoStyle, opts.InfoSep = parseInfoStyle(value)
			} else if match, value := optString(arg, "--separator="); match {
				opts.Separator = &value
			} else if match, value := optString(arg, "--scrollbar="); match {
				opts.Scrollbar = &value
			} else if match, value := optString(arg, "--toggle-sort="); match {
				parseToggleSort(opts.Keymap, value)
			} else if match, value := optString(arg, "--expect="); match {
				for k, v := range parseKeyChords(value, "key names required") {
					opts.Expect[k] = v
				}
			} else if match, value := optString(arg, "--tiebreak="); match {
				opts.Criteria = parseTiebreak(value)
			} else if match, value := optString(arg, "--color="); match {
				opts.Theme = parseTheme(opts.Theme, value)
			} else if match, value := optString(arg, "--bind="); match {
				parseKeymap(opts.Keymap, value, errorExit)
			} else if match, value := optString(arg, "--history="); match {
				setHistory(value)
			} else if match, value := optString(arg, "--history-size="); match {
				setHistoryMax(atoi(value))
			} else if match, value := optString(arg, "--header="); match {
				opts.Header = strLines(value)
			} else if match, value := optString(arg, "--header-lines="); match {
				opts.HeaderLines = atoi(value)
			} else if match, value := optString(arg, "--ellipsis="); match {
				opts.Ellipsis = value
			} else if match, value := optString(arg, "--preview="); match {
				opts.Preview.command = value
			} else if match, value := optString(arg, "--preview-window="); match {
				parsePreviewWindow(&opts.Preview, value)
			} else if match, value := optString(arg, "--margin="); match {
				opts.Margin = parseMargin("margin", value)
			} else if match, value := optString(arg, "--padding="); match {
				opts.Padding = parseMargin("padding", value)
			} else if match, value := optString(arg, "--tabstop="); match {
				opts.Tabstop = atoi(value)
			} else if match, value := optString(arg, "--listen="); match {
				port := atoi(value)
				opts.ListenPort = &port
			} else if match, value := optString(arg, "--hscroll-off="); match {
				opts.HscrollOff = atoi(value)
			} else if match, value := optString(arg, "--scroll-off="); match {
				opts.ScrollOff = atoi(value)
			} else if match, value := optString(arg, "--jump-labels="); match {
				opts.JumpLabels = value
				validateJumpLabels = true
			} else {
				errorExit("unknown option: " + arg)
			}
		}
	}

	if opts.HeaderLines < 0 {
		errorExit("header lines must be a non-negative integer")
	}

	if opts.HscrollOff < 0 {
		errorExit("hscroll offset must be a non-negative integer")
	}

	if opts.ScrollOff < 0 {
		errorExit("scroll offset must be a non-negative integer")
	}

	if opts.Tabstop < 1 {
		errorExit("tab stop must be a positive integer")
	}

	if opts.ListenPort != nil && (*opts.ListenPort < 0 || *opts.ListenPort > 65535) {
		errorExit("invalid listen port")
	}

	if len(opts.JumpLabels) == 0 {
		errorExit("empty jump labels")
	}

	if validateJumpLabels {
		for _, r := range opts.JumpLabels {
			if r < 32 || r > 126 {
				errorExit("non-ascii jump labels are not allowed")
			}
		}
	}

	if validatePointer {
		if err := validateSign(opts.Pointer, "pointer"); err != nil {
			errorExit(err.Error())
		}
	}

	if validateMarker {
		if err := validateSign(opts.Marker, "marker"); err != nil {
			errorExit(err.Error())
		}
	}
}

func validateSign(sign string, signOptName string) error {
	if sign == "" {
		return fmt.Errorf("%v cannot be empty", signOptName)
	}
	if runewidth.StringWidth(sign) > 2 {
		return fmt.Errorf("%v display width should be up to 2", signOptName)
	}
	return nil
}

func postProcessOptions(opts *Options) {
	if !opts.Version && !tui.IsLightRendererSupported() && opts.Height.size > 0 {
		errorExit("--height option is currently not supported on this platform")
	}

	if opts.Scrollbar != nil && runewidth.StringWidth(*opts.Scrollbar) > 1 {
		errorExit("scrollbar display width should be 1")
	}

	// Default actions for CTRL-N / CTRL-P when --history is set
	if opts.History != nil {
		if _, prs := opts.Keymap[tui.CtrlP.AsEvent()]; !prs {
			opts.Keymap[tui.CtrlP.AsEvent()] = toActions(actPrevHistory)
		}
		if _, prs := opts.Keymap[tui.CtrlN.AsEvent()]; !prs {
			opts.Keymap[tui.CtrlN.AsEvent()] = toActions(actNextHistory)
		}
	}

	// Extend the default key map
	keymap := defaultKeymap()
	for key, actions := range opts.Keymap {
		var lastChangePreviewWindow *action
		for _, act := range actions {
			switch act.t {
			case actToggleSort:
				// To display "+S"/"-S" on info line
				opts.ToggleSort = true
			case actChangePreviewWindow:
				lastChangePreviewWindow = act
			}
		}

		// Re-organize actions so that we only keep the last change-preview-window
		// and it comes first in the list.
		//  *  change-preview-window(up,+10)+preview(sleep 3; cat {})+change-preview-window(up,+20)
		//  -> change-preview-window(up,+20)+preview(sleep 3; cat {})
		if lastChangePreviewWindow != nil {
			reordered := []*action{lastChangePreviewWindow}
			for _, act := range actions {
				if act.t != actChangePreviewWindow {
					reordered = append(reordered, act)
				}
			}
			actions = reordered
		}
		keymap[key] = actions
	}
	opts.Keymap = keymap

	// If 'double-click' is left unbound, bind it to the action bound to 'enter'
	if _, prs := opts.Keymap[tui.DoubleClick.AsEvent()]; !prs {
		opts.Keymap[tui.DoubleClick.AsEvent()] = opts.Keymap[tui.CtrlM.AsEvent()]
	}

	if opts.Height.auto {
		for _, s := range []sizeSpec{opts.Margin[0], opts.Margin[2]} {
			if s.percent {
				errorExit("adaptive height is not compatible with top/bottom percent margin")
			}
		}
		for _, s := range []sizeSpec{opts.Padding[0], opts.Padding[2]} {
			if s.percent {
				errorExit("adaptive height is not compatible with top/bottom percent padding")
			}
		}
	}

	// If we're not using extended search mode, --nth option becomes irrelevant
	// if it contains the whole range
	if !opts.Extended || len(opts.Nth) == 1 {
		for _, r := range opts.Nth {
			if r.begin == rangeEllipsis && r.end == rangeEllipsis {
				opts.Nth = make([]Range, 0)
				return
			}
		}
	}

	if opts.Bold {
		theme := opts.Theme
		boldify := func(c tui.ColorAttr) tui.ColorAttr {
			dup := c
			if (c.Attr & tui.AttrRegular) == 0 {
				dup.Attr |= tui.Bold
			}
			return dup
		}
		theme.Current = boldify(theme.Current)
		theme.CurrentMatch = boldify(theme.CurrentMatch)
		theme.Prompt = boldify(theme.Prompt)
		theme.Input = boldify(theme.Input)
		theme.Cursor = boldify(theme.Cursor)
		theme.Spinner = boldify(theme.Spinner)
	}

	if opts.Scheme != "default" {
		processScheme(opts)
	}
}

func expectsArbitraryString(opt string) bool {
	switch opt {
	case "-q", "--query", "-f", "--filter", "--header", "--prompt":
		return true
	}
	return false
}

// ParseOptions parses command-line options
func ParseOptions() *Options {
	opts := defaultOptions()

	for idx, arg := range os.Args[1:] {
		if arg == "--version" && (idx == 0 || idx > 0 && !expectsArbitraryString(os.Args[idx])) {
			opts.Version = true
			return opts
		}
	}

	// Options from Env var
	words, _ := shellwords.Parse(os.Getenv("FZF_DEFAULT_OPTS"))
	if len(words) > 0 {
		parseOptions(opts, words)
	}

	// Options from command-line arguments
	parseOptions(opts, os.Args[1:])

	postProcessOptions(opts)
	return opts
}