package fzf

import (
	"bufio"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"math"
	"net"
	"os"
	"os/signal"
	"regexp"
	"sort"
	"strconv"
	"strings"
	"sync"
	"syscall"
	"time"

	"github.com/rivo/uniseg"

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

// import "github.com/pkg/profile"

/*
Placeholder regex is used to extract placeholders from fzf's template
strings. Acts as input validation for parsePlaceholder function.
Describes the syntax, but it is fairly lenient.

The following pseudo regex has been reverse engineered from the
implementation. It is overly strict, but better describes what's possible.
As such it is not useful for validation, but rather to generate test
cases for example.

	\\?(?:                                      # escaped type
	    {\+?s?f?RANGE(?:,RANGE)*}               # token type
	    |{q}                                    # query type
	    |{\+?n?f?}                              # item type (notice no mandatory element inside brackets)
	)
	RANGE = (?:
	    (?:-?[0-9]+)?\.\.(?:-?[0-9]+)?          # ellipsis syntax for token range (x..y)
	    |-?[0-9]+                               # shorthand syntax (x..x)
	)
*/
var placeholder *regexp.Regexp
var whiteSuffix *regexp.Regexp
var offsetComponentRegex *regexp.Regexp
var offsetTrimCharsRegex *regexp.Regexp
var passThroughRegex *regexp.Regexp
var ttyin *os.File

const clearCode string = "\x1b[2J"

// Number of maximum focus events to process synchronously
const maxFocusEvents = 10000

func init() {
	placeholder = regexp.MustCompile(`\\?(?:{[+sf]*[0-9,-.]*}|{q}|{fzf:(?:query|action|prompt)}|{\+?f?nf?})`)
	whiteSuffix = regexp.MustCompile(`\s*$`)
	offsetComponentRegex = regexp.MustCompile(`([+-][0-9]+)|(-?/[1-9][0-9]*)`)
	offsetTrimCharsRegex = regexp.MustCompile(`[^0-9/+-]`)

	// Parts of the preview output that should be passed through to the terminal
	// * https://github.com/tmux/tmux/wiki/FAQ#what-is-the-passthrough-escape-sequence-and-how-do-i-use-it
	// * https://sw.kovidgoyal.net/kitty/graphics-protocol
	// * https://en.wikipedia.org/wiki/Sixel
	// * https://iterm2.com/documentation-images.html
	passThroughRegex = regexp.MustCompile(`\x1bPtmux;\x1b\x1b.*?[^\x1b]\x1b\\|\x1b(_G|P[0-9;]*q).*?\x1b\\\r?|\x1b]1337;.*?(\a|\x1b\\)`)
}

type jumpMode int

const (
	jumpDisabled jumpMode = iota
	jumpEnabled
	jumpAcceptEnabled
)

type resumableState int

const (
	disabledState resumableState = iota
	pausedState
	enabledState
)

func (s resumableState) Enabled() bool {
	return s == enabledState
}

func (s *resumableState) Force(flag bool) {
	if flag {
		*s = enabledState
	} else {
		*s = disabledState
	}
}

func (s *resumableState) Set(flag bool) {
	if *s == disabledState {
		return
	}

	if flag {
		*s = enabledState
	} else {
		*s = pausedState
	}
}

type commandSpec struct {
	command   string
	tempFiles []string
}

type quitSignal struct {
	code int
	err  error
}

type previewer struct {
	version    int64
	lines      []string
	offset     int
	scrollable bool
	final      bool
	following  resumableState
	spinner    string
	bar        []bool
}

type previewed struct {
	version   int64
	numLines  int
	offset    int
	filled    bool
	image     bool
	wipe      bool
	wireframe bool
}

type eachLine struct {
	line string
	err  error
}

type itemLine struct {
	firstLine int
	cy        int
	current   bool
	selected  bool
	label     string
	queryLen  int
	width     int
	hasBar    bool
	result    Result
	empty     bool
	other     bool
}

func (t *Terminal) markEmptyLine(line int) {
	t.prevLines[line] = itemLine{firstLine: line, empty: true}
}

func (t *Terminal) markOtherLine(line int) {
	t.prevLines[line] = itemLine{firstLine: line, other: true}
}

type fitpad struct {
	fit int
	pad int
}

type labelPrinter func(tui.Window, int)

type markerClass int

const (
	markerSingle markerClass = iota
	markerTop
	markerMiddle
	markerBottom
)

type StatusItem struct {
	Index int    `json:"index"`
	Text  string `json:"text"`
}

type Status struct {
	Reading    bool         `json:"reading"`
	Progress   int          `json:"progress"`
	Query      string       `json:"query"`
	Position   int          `json:"position"`
	Sort       bool         `json:"sort"`
	TotalCount int          `json:"totalCount"`
	MatchCount int          `json:"matchCount"`
	Current    *StatusItem  `json:"current"`
	Matches    []StatusItem `json:"matches"`
	Selected   []StatusItem `json:"selected"`
}

// Terminal represents terminal input/output
type Terminal struct {
	initDelay          time.Duration
	infoStyle          infoStyle
	infoPrefix         string
	separator          labelPrinter
	separatorLen       int
	spinner            []string
	promptString       string
	prompt             func()
	promptLen          int
	borderLabel        labelPrinter
	borderLabelLen     int
	borderLabelOpts    labelOpts
	previewLabel       labelPrinter
	previewLabelLen    int
	previewLabelOpts   labelOpts
	pointer            string
	pointerLen         int
	pointerEmpty       string
	marker             string
	markerLen          int
	markerEmpty        string
	markerMultiLine    [3]string
	queryLen           [2]int
	layout             layoutType
	fullscreen         bool
	keepRight          bool
	hscroll            bool
	hscrollOff         int
	scrollOff          int
	wordRubout         string
	wordNext           string
	cx                 int
	cy                 int
	offset             int
	xoffset            int
	yanked             []rune
	input              []rune
	multi              int
	multiLine          bool
	sort               bool
	toggleSort         bool
	track              trackOption
	delimiter          Delimiter
	expect             map[tui.Event]string
	keymap             map[tui.Event][]*action
	keymapOrg          map[tui.Event][]*action
	pressed            string
	printQueue         []string
	printQuery         bool
	history            *History
	cycle              bool
	highlightLine      bool
	headerVisible      bool
	headerFirst        bool
	headerLines        int
	header             []string
	header0            []string
	ellipsis           string
	scrollbar          string
	previewScrollbar   string
	ansi               bool
	tabstop            int
	margin             [4]sizeSpec
	padding            [4]sizeSpec
	unicode            bool
	listenAddr         *listenAddress
	listenPort         *int
	listener           net.Listener
	listenUnsafe       bool
	borderShape        tui.BorderShape
	cleanExit          bool
	executor           *util.Executor
	paused             bool
	border             tui.Window
	window             tui.Window
	pborder            tui.Window
	pwindow            tui.Window
	borderWidth        int
	count              int
	progress           int
	hasStartActions    bool
	hasResultActions   bool
	hasFocusActions    bool
	hasLoadActions     bool
	hasResizeActions   bool
	triggerLoad        bool
	reading            bool
	running            *util.AtomicBool
	failed             *string
	jumping            jumpMode
	jumpLabels         string
	printer            func(string)
	printsep           string
	merger             *Merger
	selected           map[int32]selectedItem
	version            int64
	revision           revision
	reqBox             *util.EventBox
	initialPreviewOpts previewOpts
	previewOpts        previewOpts
	activePreviewOpts  *previewOpts
	previewer          previewer
	previewed          previewed
	previewBox         *util.EventBox
	eventBox           *util.EventBox
	mutex              sync.Mutex
	uiMutex            sync.Mutex
	initFunc           func() error
	prevLines          []itemLine
	suppress           bool
	sigstop            bool
	startChan          chan fitpad
	killChan           chan bool
	serverInputChan    chan []*action
	keyChan            chan tui.Event
	eventChan          chan tui.Event
	slab               *util.Slab
	theme              *tui.ColorTheme
	tui                tui.Renderer
	ttyin              *os.File
	executing          *util.AtomicBool
	termSize           tui.TermSize
	lastAction         actionType
	lastKey            string
	lastFocus          int32
	areaLines          int
	areaColumns        int
	forcePreview       bool
	clickHeaderLine    int
	clickHeaderColumn  int
	proxyScript        string
}

type selectedItem struct {
	at   time.Time
	item *Item
}

type byTimeOrder []selectedItem

func (a byTimeOrder) Len() int {
	return len(a)
}

func (a byTimeOrder) Swap(i, j int) {
	a[i], a[j] = a[j], a[i]
}

func (a byTimeOrder) Less(i, j int) bool {
	return a[i].at.Before(a[j].at)
}

const (
	reqPrompt util.EventType = iota
	reqInfo
	reqHeader
	reqList
	reqJump
	reqActivate
	reqReinit
	reqFullRedraw
	reqResize
	reqRedrawBorderLabel
	reqRedrawPreviewLabel
	reqClose
	reqPrintQuery
	reqPreviewEnqueue
	reqPreviewDisplay
	reqPreviewRefresh
	reqPreviewDelayed
	reqBecome
	reqQuit
	reqFatal
)

type action struct {
	t actionType
	a string
}

//go:generate stringer -type=actionType
type actionType int

const (
	actIgnore actionType = iota
	actStart
	actClick
	actInvalid
	actChar
	actMouse
	actBeginningOfLine
	actAbort
	actAccept
	actAcceptNonEmpty
	actAcceptOrPrintQuery
	actBackwardChar
	actBackwardDeleteChar
	actBackwardDeleteCharEof
	actBackwardWord
	actCancel
	actChangeBorderLabel
	actChangeHeader
	actChangeMulti
	actChangePreviewLabel
	actChangePrompt
	actChangeQuery
	actClearScreen
	actClearQuery
	actClearSelection
	actClose
	actDeleteChar
	actDeleteCharEof
	actEndOfLine
	actFatal
	actForwardChar
	actForwardWord
	actKillLine
	actKillWord
	actUnixLineDiscard
	actUnixWordRubout
	actYank
	actBackwardKillWord
	actSelectAll
	actDeselectAll
	actToggle
	actToggleSearch
	actToggleAll
	actToggleDown
	actToggleUp
	actToggleIn
	actToggleOut
	actToggleTrack
	actToggleTrackCurrent
	actToggleHeader
	actTrackCurrent
	actUntrackCurrent
	actDown
	actUp
	actPageUp
	actPageDown
	actPosition
	actHalfPageUp
	actHalfPageDown
	actOffsetUp
	actOffsetDown
	actOffsetMiddle
	actJump
	actJumpAccept // XXX Deprecated in favor of jump:accept binding
	actPrintQuery // XXX Deprecated (not very useful, just use --print-query)
	actRefreshPreview
	actReplaceQuery
	actToggleSort
	actShowPreview
	actHidePreview
	actTogglePreview
	actTogglePreviewWrap
	actTransform
	actTransformBorderLabel
	actTransformHeader
	actTransformPreviewLabel
	actTransformPrompt
	actTransformQuery
	actPreview
	actChangePreview
	actChangePreviewWindow
	actPreviewTop
	actPreviewBottom
	actPreviewUp
	actPreviewDown
	actPreviewPageUp
	actPreviewPageDown
	actPreviewHalfPageUp
	actPreviewHalfPageDown
	actPrevHistory
	actPrevSelected
	actPrint
	actPut
	actNextHistory
	actNextSelected
	actExecute
	actExecuteSilent
	actExecuteMulti // Deprecated
	actSigStop
	actFirst
	actLast
	actReload
	actReloadSync
	actDisableSearch
	actEnableSearch
	actSelect
	actDeselect
	actUnbind
	actRebind
	actBecome
	actShowHeader
	actHideHeader
)

func (a actionType) Name() string {
	return util.ToKebabCase(a.String()[3:])
}

func processExecution(action actionType) bool {
	switch action {
	case actTransform,
		actTransformBorderLabel,
		actTransformHeader,
		actTransformPreviewLabel,
		actTransformPrompt,
		actTransformQuery,
		actPreview,
		actChangePreview,
		actRefreshPreview,
		actExecute,
		actExecuteSilent,
		actExecuteMulti,
		actReload,
		actReloadSync,
		actBecome:
		return true
	}
	return false
}

type placeholderFlags struct {
	plus          bool
	preserveSpace bool
	number        bool
	forceUpdate   bool
	file          bool
}

type searchRequest struct {
	sort    bool
	sync    bool
	command *commandSpec
	environ []string
	changed bool
}

type previewRequest struct {
	template     string
	pwindow      tui.Window
	pwindowSize  tui.TermSize
	scrollOffset int
	list         []*Item
	env          []string
}

type previewResult struct {
	version int64
	lines   []string
	offset  int
	spinner string
}

func toActions(types ...actionType) []*action {
	actions := make([]*action, len(types))
	for idx, t := range types {
		actions[idx] = &action{t: t, a: ""}
	}
	return actions
}

func defaultKeymap() map[tui.Event][]*action {
	keymap := make(map[tui.Event][]*action)
	add := func(e tui.EventType, a actionType) {
		keymap[e.AsEvent()] = toActions(a)
	}
	addEvent := func(e tui.Event, a actionType) {
		keymap[e] = toActions(a)
	}

	add(tui.Fatal, actFatal)
	add(tui.Invalid, actInvalid)
	add(tui.CtrlA, actBeginningOfLine)
	add(tui.CtrlB, actBackwardChar)
	add(tui.CtrlC, actAbort)
	add(tui.CtrlG, actAbort)
	add(tui.CtrlQ, actAbort)
	add(tui.Esc, actAbort)
	add(tui.CtrlD, actDeleteCharEof)
	add(tui.CtrlE, actEndOfLine)
	add(tui.CtrlF, actForwardChar)
	add(tui.CtrlH, actBackwardDeleteChar)
	add(tui.Backspace, actBackwardDeleteChar)
	add(tui.Tab, actToggleDown)
	add(tui.ShiftTab, actToggleUp)
	add(tui.CtrlJ, actDown)
	add(tui.CtrlK, actUp)
	add(tui.CtrlL, actClearScreen)
	add(tui.CtrlM, actAccept)
	add(tui.CtrlN, actDown)
	add(tui.CtrlP, actUp)
	add(tui.CtrlU, actUnixLineDiscard)
	add(tui.CtrlW, actUnixWordRubout)
	add(tui.CtrlY, actYank)
	if !util.IsWindows() {
		add(tui.CtrlZ, actSigStop)
	}

	addEvent(tui.AltKey('b'), actBackwardWord)
	add(tui.ShiftLeft, actBackwardWord)
	addEvent(tui.AltKey('f'), actForwardWord)
	add(tui.ShiftRight, actForwardWord)
	addEvent(tui.AltKey('d'), actKillWord)
	add(tui.AltBackspace, actBackwardKillWord)

	add(tui.Up, actUp)
	add(tui.Down, actDown)
	add(tui.Left, actBackwardChar)
	add(tui.Right, actForwardChar)

	add(tui.Home, actBeginningOfLine)
	add(tui.End, actEndOfLine)
	add(tui.Delete, actDeleteChar)
	add(tui.PageUp, actPageUp)
	add(tui.PageDown, actPageDown)

	add(tui.ShiftUp, actPreviewUp)
	add(tui.ShiftDown, actPreviewDown)

	add(tui.Mouse, actMouse)
	add(tui.LeftClick, actClick)
	add(tui.RightClick, actToggle)
	add(tui.SLeftClick, actToggle)
	add(tui.SRightClick, actToggle)

	add(tui.ScrollUp, actUp)
	add(tui.ScrollDown, actDown)
	keymap[tui.SScrollUp.AsEvent()] = toActions(actToggle, actUp)
	keymap[tui.SScrollDown.AsEvent()] = toActions(actToggle, actDown)

	add(tui.PreviewScrollUp, actPreviewUp)
	add(tui.PreviewScrollDown, actPreviewDown)
	return keymap
}

func trimQuery(query string) []rune {
	return []rune(strings.ReplaceAll(query, "\t", " "))
}

func mayTriggerPreview(opts *Options) bool {
	if opts.ListenAddr != nil {
		return true
	}
	for _, actions := range opts.Keymap {
		for _, action := range actions {
			switch action.t {
			case actPreview, actChangePreview, actTransform:
				return true
			}
		}
	}
	return false
}

func makeSpinner(unicode bool) []string {
	if unicode {
		return []string{`⠋`, `⠙`, `⠹`, `⠸`, `⠼`, `⠴`, `⠦`, `⠧`, `⠇`, `⠏`}
	}
	return []string{`-`, `\`, `|`, `/`, `-`, `\`, `|`, `/`}
}

func evaluateHeight(opts *Options, termHeight int) int {
	size := opts.Height.size
	if opts.Height.percent {
		if opts.Height.inverse {
			size = 100 - size
		}
		return util.Max(int(size*float64(termHeight)/100.0), opts.MinHeight)
	}
	if opts.Height.inverse {
		size = float64(termHeight) - size
	}
	return int(size)
}

// NewTerminal returns new Terminal object
func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor) (*Terminal, error) {
	input := trimQuery(opts.Query)
	var delay time.Duration
	if opts.Sync {
		delay = 0
	} else if opts.Tac {
		delay = initialDelayTac
	} else {
		delay = initialDelay
	}
	var previewBox *util.EventBox
	// We need to start the previewer even when --preview option is not specified
	// * if HTTP server is enabled
	// * if 'preview' or 'change-preview' action is bound to a key
	// * if 'transform' action is bound to a key
	if len(opts.Preview.command) > 0 || mayTriggerPreview(opts) {
		previewBox = util.NewEventBox()
	}
	var renderer tui.Renderer
	fullscreen := !opts.Height.auto && (opts.Height.size == 0 || opts.Height.percent && opts.Height.size == 100)
	var err error
	// Reuse ttyin if available to avoid having multiple file descriptors open
	// when you run fzf multiple times in your Go program. Closing it is known to
	// cause problems with 'become' action and invalid terminal state after exit.
	if ttyin == nil {
		if ttyin, err = tui.TtyIn(); err != nil {
			return nil, err
		}
	}
	if fullscreen {
		if !tui.IsLightRendererSupported() {
			renderer = tui.NewFullscreenRenderer(opts.Theme, opts.Black, opts.Mouse)
		} else {
			renderer, err = tui.NewLightRenderer(ttyin, opts.Theme, opts.Black, opts.Mouse, opts.Tabstop, opts.ClearOnExit,
				true, func(h int) int { return h })
		}
	} else {
		maxHeightFunc := func(termHeight int) int {
			// Minimum height required to render fzf excluding margin and padding
			effectiveMinHeight := minHeight
			if previewBox != nil && opts.Preview.aboveOrBelow() {
				effectiveMinHeight += 1 + borderLines(opts.Preview.border)
			}
			if noSeparatorLine(opts.InfoStyle, opts.Separator == nil || uniseg.StringWidth(*opts.Separator) > 0) {
				effectiveMinHeight--
			}
			effectiveMinHeight += borderLines(opts.BorderShape)
			return util.Min(termHeight, util.Max(evaluateHeight(opts, termHeight), effectiveMinHeight))
		}
		renderer, err = tui.NewLightRenderer(ttyin, opts.Theme, opts.Black, opts.Mouse, opts.Tabstop, opts.ClearOnExit, false, maxHeightFunc)
	}
	if err != nil {
		return nil, err
	}
	wordRubout := "[^\\pL\\pN][\\pL\\pN]"
	wordNext := "[\\pL\\pN][^\\pL\\pN]|(.$)"
	if opts.FileWord {
		sep := regexp.QuoteMeta(string(os.PathSeparator))
		wordRubout = fmt.Sprintf("%s[^%s]", sep, sep)
		wordNext = fmt.Sprintf("[^%s]%s|(.$)", sep, sep)
	}
	keymapCopy := make(map[tui.Event][]*action)
	for key, action := range opts.Keymap {
		keymapCopy[key] = action
	}

	t := Terminal{
		initDelay:          delay,
		infoStyle:          opts.InfoStyle,
		infoPrefix:         opts.InfoPrefix,
		separator:          nil,
		spinner:            makeSpinner(opts.Unicode),
		promptString:       opts.Prompt,
		queryLen:           [2]int{0, 0},
		layout:             opts.Layout,
		fullscreen:         fullscreen,
		keepRight:          opts.KeepRight,
		hscroll:            opts.Hscroll,
		hscrollOff:         opts.HscrollOff,
		scrollOff:          opts.ScrollOff,
		pointer:            *opts.Pointer,
		pointerLen:         uniseg.StringWidth(*opts.Pointer),
		marker:             *opts.Marker,
		markerLen:          uniseg.StringWidth(*opts.Marker),
		markerMultiLine:    opts.MarkerMulti,
		wordRubout:         wordRubout,
		wordNext:           wordNext,
		cx:                 len(input),
		cy:                 0,
		offset:             0,
		xoffset:            0,
		yanked:             []rune{},
		input:              input,
		multi:              opts.Multi,
		multiLine:          opts.ReadZero && opts.MultiLine,
		sort:               opts.Sort > 0,
		toggleSort:         opts.ToggleSort,
		track:              opts.Track,
		delimiter:          opts.Delimiter,
		expect:             opts.Expect,
		keymap:             opts.Keymap,
		keymapOrg:          keymapCopy,
		pressed:            "",
		printQuery:         opts.PrintQuery,
		history:            opts.History,
		margin:             opts.Margin,
		padding:            opts.Padding,
		unicode:            opts.Unicode,
		listenAddr:         opts.ListenAddr,
		listenUnsafe:       opts.Unsafe,
		borderShape:        opts.BorderShape,
		borderWidth:        1,
		borderLabel:        nil,
		borderLabelOpts:    opts.BorderLabel,
		previewLabel:       nil,
		previewLabelOpts:   opts.PreviewLabel,
		cleanExit:          opts.ClearOnExit,
		executor:           executor,
		paused:             opts.Phony,
		cycle:              opts.Cycle,
		highlightLine:      opts.CursorLine,
		headerVisible:      true,
		headerFirst:        opts.HeaderFirst,
		headerLines:        opts.HeaderLines,
		header:             []string{},
		header0:            opts.Header,
		ellipsis:           opts.Ellipsis,
		ansi:               opts.Ansi,
		tabstop:            opts.Tabstop,
		hasStartActions:    false,
		hasResultActions:   false,
		hasFocusActions:    false,
		hasLoadActions:     false,
		triggerLoad:        false,
		reading:            true,
		running:            util.NewAtomicBool(true),
		failed:             nil,
		jumping:            jumpDisabled,
		jumpLabels:         opts.JumpLabels,
		printer:            opts.Printer,
		printsep:           opts.PrintSep,
		proxyScript:        opts.ProxyScript,
		merger:             EmptyMerger(revision{}),
		selected:           make(map[int32]selectedItem),
		reqBox:             util.NewEventBox(),
		initialPreviewOpts: opts.Preview,
		previewOpts:        opts.Preview,
		previewer:          previewer{0, []string{}, 0, false, true, disabledState, "", []bool{}},
		previewed:          previewed{0, 0, 0, false, false, false, false},
		previewBox:         previewBox,
		eventBox:           eventBox,
		mutex:              sync.Mutex{},
		uiMutex:            sync.Mutex{},
		suppress:           true,
		sigstop:            false,
		slab:               util.MakeSlab(slab16Size, slab32Size),
		theme:              opts.Theme,
		startChan:          make(chan fitpad, 1),
		killChan:           make(chan bool),
		serverInputChan:    make(chan []*action, 100),
		keyChan:            make(chan tui.Event),
		eventChan:          make(chan tui.Event, 6), // start | (load + result + zero|one) | (focus) | (resize)
		tui:                renderer,
		ttyin:              ttyin,
		initFunc:           func() error { return renderer.Init() },
		executing:          util.NewAtomicBool(false),
		lastAction:         actStart,
		lastFocus:          minItem.Index()}
	t.prompt, t.promptLen = t.parsePrompt(opts.Prompt)
	// Pre-calculated empty pointer and marker signs
	t.pointerEmpty = strings.Repeat(" ", t.pointerLen)
	t.markerEmpty = strings.Repeat(" ", t.markerLen)
	t.borderLabel, t.borderLabelLen = t.ansiLabelPrinter(opts.BorderLabel.label, &tui.ColBorderLabel, false)
	t.previewLabel, t.previewLabelLen = t.ansiLabelPrinter(opts.PreviewLabel.label, &tui.ColPreviewLabel, false)
	if opts.Separator == nil || len(*opts.Separator) > 0 {
		bar := "─"
		if opts.Separator != nil {
			bar = *opts.Separator
		} else if !t.unicode {
			bar = "-"
		}
		t.separator, t.separatorLen = t.ansiLabelPrinter(bar, &tui.ColSeparator, true)
	}
	if t.unicode {
		t.borderWidth = uniseg.StringWidth("│")
	}
	if opts.Scrollbar == nil {
		if t.unicode && t.borderWidth == 1 {
			t.scrollbar = "│"
		} else {
			t.scrollbar = "|"
		}
		t.previewScrollbar = t.scrollbar
	} else {
		runes := []rune(*opts.Scrollbar)
		if len(runes) > 0 {
			t.scrollbar = string(runes[0])
			t.previewScrollbar = t.scrollbar
			if len(runes) > 1 {
				t.previewScrollbar = string(runes[1])
			}
		}
	}

	var resizeActions []*action
	resizeActions, t.hasResizeActions = t.keymap[tui.Resize.AsEvent()]
	if t.tui.ShouldEmitResizeEvent() {
		t.keymap[tui.Resize.AsEvent()] = append(toActions(actClearScreen), resizeActions...)
	}
	_, t.hasStartActions = t.keymap[tui.Start.AsEvent()]
	_, t.hasResultActions = t.keymap[tui.Result.AsEvent()]
	_, t.hasFocusActions = t.keymap[tui.Focus.AsEvent()]
	_, t.hasLoadActions = t.keymap[tui.Load.AsEvent()]

	if t.listenAddr != nil {
		listener, port, err := startHttpServer(*t.listenAddr, t.serverInputChan, t.dumpStatus)
		if err != nil {
			return nil, err
		}
		t.listener = listener
		t.listenPort = &port
	}

	if t.hasStartActions {
		t.eventChan <- tui.Start.AsEvent()
	}

	return &t, nil
}

func (t *Terminal) deferActivation() bool {
	return t.initDelay == 0 && (t.hasStartActions || t.hasLoadActions || t.hasResultActions || t.hasFocusActions)
}

func (t *Terminal) environ() []string {
	env := os.Environ()
	if t.listenPort != nil {
		env = append(env, fmt.Sprintf("FZF_PORT=%d", *t.listenPort))
	}
	env = append(env, "FZF_QUERY="+string(t.input))
	env = append(env, "FZF_ACTION="+t.lastAction.Name())
	env = append(env, "FZF_KEY="+t.lastKey)
	env = append(env, "FZF_PROMPT="+string(t.promptString))
	env = append(env, "FZF_PREVIEW_LABEL="+t.previewLabelOpts.label)
	env = append(env, "FZF_BORDER_LABEL="+t.borderLabelOpts.label)
	env = append(env, fmt.Sprintf("FZF_TOTAL_COUNT=%d", t.count))
	env = append(env, fmt.Sprintf("FZF_MATCH_COUNT=%d", t.merger.Length()))
	env = append(env, fmt.Sprintf("FZF_SELECT_COUNT=%d", len(t.selected)))
	env = append(env, fmt.Sprintf("FZF_LINES=%d", t.areaLines))
	env = append(env, fmt.Sprintf("FZF_COLUMNS=%d", t.areaColumns))
	env = append(env, fmt.Sprintf("FZF_POS=%d", util.Min(t.merger.Length(), t.cy+1)))
	env = append(env, fmt.Sprintf("FZF_CLICK_HEADER_LINE=%d", t.clickHeaderLine))
	env = append(env, fmt.Sprintf("FZF_CLICK_HEADER_COLUMN=%d", t.clickHeaderColumn))
	return env
}

func borderLines(shape tui.BorderShape) int {
	switch shape {
	case tui.BorderHorizontal, tui.BorderRounded, tui.BorderSharp, tui.BorderBold, tui.BorderBlock, tui.BorderThinBlock, tui.BorderDouble:
		return 2
	case tui.BorderTop, tui.BorderBottom:
		return 1
	}
	return 0
}

func (t *Terminal) visibleHeaderLines() int {
	if !t.headerVisible {
		return 0
	}
	return len(t.header0) + t.headerLines
}

// Extra number of lines needed to display fzf
func (t *Terminal) extraLines() int {
	extra := t.visibleHeaderLines() + 1
	if !t.noSeparatorLine() {
		extra++
	}
	return extra
}

func (t *Terminal) MaxFitAndPad() (int, int) {
	_, screenHeight, marginInt, paddingInt := t.adjustMarginAndPadding()
	padHeight := marginInt[0] + marginInt[2] + paddingInt[0] + paddingInt[2]
	fit := screenHeight - padHeight - t.extraLines()
	return fit, padHeight
}

func (t *Terminal) ansiLabelPrinter(str string, color *tui.ColorPair, fill bool) (labelPrinter, int) {
	// Nothing to do
	if len(str) == 0 {
		return nil, 0
	}

	// Extract ANSI color codes
	str = firstLine(str)
	text, colors, _ := extractColor(str, nil, nil)
	runes := []rune(text)

	// Simpler printer for strings without ANSI colors or tab characters
	if colors == nil && !strings.ContainsRune(str, '\t') {
		length := util.StringWidth(str)
		if length == 0 {
			return nil, 0
		}
		printFn := func(window tui.Window, limit int) {
			if length > limit {
				trimmedRunes, _ := t.trimRight(runes, limit)
				window.CPrint(*color, string(trimmedRunes))
			} else if fill {
				window.CPrint(*color, util.RepeatToFill(str, length, limit))
			} else {
				window.CPrint(*color, str)
			}
		}
		return printFn, length
	}

	// Printer that correctly handles ANSI color codes and tab characters
	item := &Item{text: util.RunesToChars(runes), colors: colors}
	length := t.displayWidth(runes)
	if length == 0 {
		return nil, 0
	}
	result := Result{item: item}
	var offsets []colorOffset
	printFn := func(window tui.Window, limit int) {
		if offsets == nil {
			// tui.Col* are not initialized until renderer.Init()
			offsets = result.colorOffsets(nil, t.theme, *color, *color, false)
		}
		for limit > 0 {
			if length > limit {
				trimmedRunes, _ := t.trimRight(runes, limit)
				t.printColoredString(window, trimmedRunes, offsets, *color)
				break
			} else if fill {
				t.printColoredString(window, runes, offsets, *color)
				limit -= length
			} else {
				t.printColoredString(window, runes, offsets, *color)
				break
			}
		}
	}
	return printFn, length
}

func (t *Terminal) parsePrompt(prompt string) (func(), int) {
	var state *ansiState
	prompt = firstLine(prompt)
	trimmed, colors, _ := extractColor(prompt, state, nil)
	item := &Item{text: util.ToChars([]byte(trimmed)), colors: colors}

	// "Prompt>  "
	//  -------    // Do not apply ANSI attributes to the trailing whitespaces
	//             // unless the part has a non-default ANSI state
	loc := whiteSuffix.FindStringIndex(trimmed)
	if loc != nil {
		blankState := ansiOffset{[2]int32{int32(loc[0]), int32(loc[1])}, ansiState{-1, -1, tui.AttrClear, -1}}
		if item.colors != nil {
			lastColor := (*item.colors)[len(*item.colors)-1]
			if lastColor.offset[1] < int32(loc[1]) {
				blankState.offset[0] = lastColor.offset[1]
				colors := append(*item.colors, blankState)
				item.colors = &colors
			}
		} else {
			colors := []ansiOffset{blankState}
			item.colors = &colors
		}
	}
	output := func() {
		line := t.promptLine()
		t.printHighlighted(
			Result{item: item}, tui.ColPrompt, tui.ColPrompt, false, false, line, line, true, nil, nil)
	}
	_, promptLen := t.processTabs([]rune(trimmed), 0)

	return output, promptLen
}

func noSeparatorLine(style infoStyle, separator bool) bool {
	switch style {
	case infoInline:
		return true
	case infoHidden, infoInlineRight:
		return !separator
	}
	return false
}

func (t *Terminal) noSeparatorLine() bool {
	return noSeparatorLine(t.infoStyle, t.separatorLen > 0)
}

func getScrollbar(perLine int, total int, height int, offset int) (int, int) {
	if total == 0 || total*perLine <= height {
		return 0, 0
	}
	barLength := util.Max(1, height*height/(total*perLine))
	var barStart int
	if total == height {
		barStart = 0
	} else {
		barStart = util.Min(height-barLength, (height*perLine-barLength)*offset/(total*perLine-height))
	}
	return barLength, barStart
}

// Estimate the average number of lines per item. Instead of going through all
// items, we only check a few items around the current cursor position.
func (t *Terminal) avgNumLines() int {
	if !t.multiLine {
		return 1
	}

	maxItems := t.maxItems()
	numLines := 0
	count := 0
	total := t.merger.Length()
	offset := util.Max(0, util.Min(t.offset, total-maxItems-1))
	for idx := 0; idx < maxItems && idx+offset < total; idx++ {
		item := t.merger.Get(idx + offset)
		lines, _ := item.item.text.NumLines(maxItems)
		numLines += lines
		count++
	}
	if count == 0 {
		return 1
	}
	return numLines / count
}

func (t *Terminal) getScrollbar() (int, int) {
	return getScrollbar(t.avgNumLines(), t.merger.Length(), t.maxItems(), t.offset)
}

// Input returns current query string
func (t *Terminal) Input() (bool, []rune) {
	t.mutex.Lock()
	defer t.mutex.Unlock()
	return t.paused, copySlice(t.input)
}

// UpdateCount updates the count information
func (t *Terminal) UpdateCount(cnt int, final bool, failedCommand *string) {
	t.mutex.Lock()
	t.count = cnt
	if t.hasLoadActions && t.reading && final {
		t.triggerLoad = true
	}
	t.reading = !final
	t.failed = failedCommand
	suppressed := t.suppress
	t.mutex.Unlock()
	t.reqBox.Set(reqInfo, nil)

	// We want to defer activating the interface when --sync is used and any of
	// start, load, or result events are bound
	if suppressed && final && !t.deferActivation() {
		t.reqBox.Set(reqActivate, nil)
	}
}

func (t *Terminal) changeHeader(header string) bool {
	lines := strings.Split(strings.TrimSuffix(header, "\n"), "\n")
	needFullRedraw := len(t.header0) != len(lines)
	t.header0 = lines
	return needFullRedraw
}

// UpdateHeader updates the header
func (t *Terminal) UpdateHeader(header []string) {
	t.mutex.Lock()
	t.header = header
	t.mutex.Unlock()
	t.reqBox.Set(reqHeader, nil)
}

// UpdateProgress updates the search progress
func (t *Terminal) UpdateProgress(progress float32) {
	t.mutex.Lock()
	newProgress := int(progress * 100)
	changed := t.progress != newProgress
	t.progress = newProgress
	t.mutex.Unlock()

	if changed {
		t.reqBox.Set(reqInfo, nil)
	}
}

// UpdateList updates Merger to display the list
func (t *Terminal) UpdateList(merger *Merger) {
	t.mutex.Lock()
	prevIndex := minItem.Index()
	newRevision := merger.Revision()
	if t.revision.compatible(newRevision) && t.track != trackDisabled {
		if t.merger.Length() > 0 {
			prevIndex = t.currentIndex()
		} else if merger.Length() > 0 {
			prevIndex = merger.First().item.Index()
		}
	}
	t.progress = 100
	t.merger = merger
	if t.revision != newRevision {
		if !t.revision.compatible(newRevision) {
			// Reloaded: clear selection
			t.selected = make(map[int32]selectedItem)
		} else {
			// Trimmed by --tail: filter selection by index
			filtered := make(map[int32]selectedItem)
			minIndex := merger.minIndex
			maxIndex := minIndex + int32(merger.Length())
			for k, v := range t.selected {
				var included bool
				if maxIndex > minIndex {
					included = k >= minIndex && k < maxIndex
				} else { // int32 overflow [==>   <==]
					included = k >= minIndex || k < maxIndex
				}
				if included {
					filtered[k] = v
				}
			}
			t.selected = filtered
		}
		t.revision = newRevision
		t.version++
	}
	if t.triggerLoad {
		t.triggerLoad = false
		t.eventChan <- tui.Load.AsEvent()
	}
	if prevIndex >= 0 {
		pos := t.cy - t.offset
		count := t.merger.Length()
		i := t.merger.FindIndex(prevIndex)
		if i >= 0 {
			t.cy = i
			t.offset = t.cy - pos
		} else if t.track == trackCurrent {
			t.track = trackDisabled
			t.cy = pos
			t.offset = 0
		} else if t.cy > count {
			// Try to keep the vertical position when the list shrinks
			t.cy = count - util.Min(count, t.maxItems()) + pos
		}
	}
	needActivation := false
	if !t.reading {
		switch t.merger.Length() {
		case 0:
			zero := tui.Zero.AsEvent()
			if _, prs := t.keymap[zero]; prs {
				t.eventChan <- zero
			}
			// --sync, only 'focus' is bound, but no items to focus
			needActivation = t.suppress && !t.hasResultActions && !t.hasLoadActions && t.hasFocusActions
		case 1:
			one := tui.One.AsEvent()
			if _, prs := t.keymap[one]; prs {
				t.eventChan <- one
			}
		}
	}
	if t.hasResultActions {
		t.eventChan <- tui.Result.AsEvent()
	}
	t.mutex.Unlock()
	t.reqBox.Set(reqInfo, nil)
	t.reqBox.Set(reqList, nil)
	if needActivation {
		t.reqBox.Set(reqActivate, nil)
	}
}

func (t *Terminal) output() bool {
	if t.printQuery {
		t.printer(string(t.input))
	}
	if len(t.expect) > 0 {
		t.printer(t.pressed)
	}
	for _, s := range t.printQueue {
		t.printer(s)
	}
	found := len(t.selected) > 0
	if !found {
		current := t.currentItem()
		if current != nil {
			t.printer(current.AsString(t.ansi))
			found = true
		}
	} else {
		for _, sel := range t.sortSelected() {
			t.printer(sel.item.AsString(t.ansi))
		}
	}
	return found
}

func (t *Terminal) sortSelected() []selectedItem {
	sels := make([]selectedItem, 0, len(t.selected))
	for _, sel := range t.selected {
		sels = append(sels, sel)
	}
	sort.Sort(byTimeOrder(sels))
	return sels
}

func (t *Terminal) displayWidth(runes []rune) int {
	width, _ := util.RunesWidth(runes, 0, t.tabstop, math.MaxInt32)
	return width
}

const (
	minWidth  = 4
	minHeight = 3
)

func calculateSize(base int, size sizeSpec, occupied int, minSize int, pad int) int {
	max := base - occupied
	if max < minSize {
		max = minSize
	}
	if size.percent {
		return util.Constrain(int(float64(base)*0.01*size.size), minSize, max)
	}
	return util.Constrain(int(size.size)+pad, minSize, max)
}

func (t *Terminal) adjustMarginAndPadding() (int, int, [4]int, [4]int) {
	screenWidth := t.tui.MaxX()
	screenHeight := t.tui.MaxY()
	marginInt := [4]int{}  // TRBL
	paddingInt := [4]int{} // TRBL
	sizeSpecToInt := func(index int, spec sizeSpec) int {
		if spec.percent {
			var max float64
			if index%2 == 0 {
				max = float64(screenHeight)
			} else {
				max = float64(screenWidth)
			}
			return int(max * spec.size * 0.01)
		}
		return int(spec.size)
	}
	for idx, sizeSpec := range t.padding {
		paddingInt[idx] = sizeSpecToInt(idx, sizeSpec)
	}

	bw := t.borderWidth
	extraMargin := [4]int{} // TRBL
	for idx, sizeSpec := range t.margin {
		switch t.borderShape {
		case tui.BorderHorizontal:
			extraMargin[idx] += 1 - idx%2
		case tui.BorderVertical:
			extraMargin[idx] += (1 + bw) * (idx % 2)
		case tui.BorderTop:
			if idx == 0 {
				extraMargin[idx]++
			}
		case tui.BorderRight:
			if idx == 1 {
				extraMargin[idx] += 1 + bw
			}
		case tui.BorderBottom:
			if idx == 2 {
				extraMargin[idx]++
			}
		case tui.BorderLeft:
			if idx == 3 {
				extraMargin[idx] += 1 + bw
			}
		case tui.BorderRounded, tui.BorderSharp, tui.BorderBold, tui.BorderBlock, tui.BorderThinBlock, tui.BorderDouble:
			extraMargin[idx] += 1 + bw*(idx%2)
		}
		marginInt[idx] = sizeSpecToInt(idx, sizeSpec) + extraMargin[idx]
	}

	adjust := func(idx1 int, idx2 int, max int, min int) {
		if min > max {
			min = max
		}
		margin := marginInt[idx1] + marginInt[idx2] + paddingInt[idx1] + paddingInt[idx2]
		if max-margin < min {
			desired := max - min
			paddingInt[idx1] = desired * paddingInt[idx1] / margin
			paddingInt[idx2] = desired * paddingInt[idx2] / margin
			marginInt[idx1] = util.Max(extraMargin[idx1], desired*marginInt[idx1]/margin)
			marginInt[idx2] = util.Max(extraMargin[idx2], desired*marginInt[idx2]/margin)
		}
	}

	minAreaWidth := minWidth
	minAreaHeight := minHeight
	if t.noSeparatorLine() {
		minAreaHeight -= 1
	}
	if t.needPreviewWindow() {
		minPreviewHeight := 1 + borderLines(t.previewOpts.border)
		minPreviewWidth := 5
		switch t.previewOpts.position {
		case posUp, posDown:
			minAreaHeight += minPreviewHeight
			minAreaWidth = util.Max(minPreviewWidth, minAreaWidth)
		case posLeft, posRight:
			minAreaWidth += minPreviewWidth
			minAreaHeight = util.Max(minPreviewHeight, minAreaHeight)
		}
	}
	adjust(1, 3, screenWidth, minAreaWidth)
	adjust(0, 2, screenHeight, minAreaHeight)

	return screenWidth, screenHeight, marginInt, paddingInt
}

func (t *Terminal) resizeWindows(forcePreview bool) {
	t.forcePreview = forcePreview
	screenWidth, screenHeight, marginInt, paddingInt := t.adjustMarginAndPadding()
	width := screenWidth - marginInt[1] - marginInt[3]
	height := screenHeight - marginInt[0] - marginInt[2]

	t.prevLines = make([]itemLine, screenHeight)
	if t.border != nil {
		t.border.Close()
	}
	if t.window != nil {
		t.window.Close()
		t.window = nil
	}
	if t.pborder != nil {
		t.pborder.Close()
		t.pborder = nil
	}
	hadPreviewWindow := t.hasPreviewWindow()
	if hadPreviewWindow {
		t.pwindow.Close()
		t.pwindow = nil
	}
	// Reset preview version so that full redraw occurs
	t.previewed.version = 0

	bw := t.borderWidth
	switch t.borderShape {
	case tui.BorderHorizontal:
		t.border = t.tui.NewWindow(
			marginInt[0]-1, marginInt[3], width, height+2,
			false, tui.MakeBorderStyle(tui.BorderHorizontal, t.unicode))
	case tui.BorderVertical:
		t.border = t.tui.NewWindow(
			marginInt[0], marginInt[3]-(1+bw), width+(1+bw)*2, height,
			false, tui.MakeBorderStyle(tui.BorderVertical, t.unicode))
	case tui.BorderTop:
		t.border = t.tui.NewWindow(
			marginInt[0]-1, marginInt[3], width, height+1,
			false, tui.MakeBorderStyle(tui.BorderTop, t.unicode))
	case tui.BorderBottom:
		t.border = t.tui.NewWindow(
			marginInt[0], marginInt[3], width, height+1,
			false, tui.MakeBorderStyle(tui.BorderBottom, t.unicode))
	case tui.BorderLeft:
		t.border = t.tui.NewWindow(
			marginInt[0], marginInt[3]-(1+bw), width+(1+bw), height,
			false, tui.MakeBorderStyle(tui.BorderLeft, t.unicode))
	case tui.BorderRight:
		t.border = t.tui.NewWindow(
			marginInt[0], marginInt[3], width+(1+bw), height,
			false, tui.MakeBorderStyle(tui.BorderRight, t.unicode))
	case tui.BorderRounded, tui.BorderSharp, tui.BorderBold, tui.BorderBlock, tui.BorderThinBlock, tui.BorderDouble:
		t.border = t.tui.NewWindow(
			marginInt[0]-1, marginInt[3]-(1+bw), width+(1+bw)*2, height+2,
			false, tui.MakeBorderStyle(t.borderShape, t.unicode))
	}

	// Add padding to margin
	for idx, val := range paddingInt {
		marginInt[idx] += val
	}
	width -= paddingInt[1] + paddingInt[3]
	height -= paddingInt[0] + paddingInt[2]

	t.areaLines = height
	t.areaColumns = width

	// Set up preview window
	noBorder := tui.MakeBorderStyle(tui.BorderNone, t.unicode)
	if forcePreview || t.needPreviewWindow() {
		var resizePreviewWindows func(previewOpts *previewOpts)
		resizePreviewWindows = func(previewOpts *previewOpts) {
			t.activePreviewOpts = previewOpts
			if previewOpts.size.size == 0 {
				return
			}
			hasThreshold := previewOpts.threshold > 0 && previewOpts.alternative != nil
			createPreviewWindow := func(y int, x int, w int, h int) {
				pwidth := w
				pheight := h
				var previewBorder tui.BorderStyle
				if previewOpts.border == tui.BorderNone {
					previewBorder = tui.MakeTransparentBorder()
				} else {
					previewBorder = tui.MakeBorderStyle(previewOpts.border, t.unicode)
				}
				t.pborder = t.tui.NewWindow(y, x, w, h, true, previewBorder)
				switch previewOpts.border {
				case tui.BorderSharp, tui.BorderRounded, tui.BorderBold, tui.BorderBlock, tui.BorderThinBlock, tui.BorderDouble:
					pwidth -= (1 + bw) * 2
					pheight -= 2
					x += 1 + bw
					y += 1
				case tui.BorderLeft:
					pwidth -= 1 + bw
					x += 1 + bw
				case tui.BorderRight:
					pwidth -= 1 + bw
				case tui.BorderTop:
					pheight -= 1
					y += 1
				case tui.BorderBottom:
					pheight -= 1
				case tui.BorderHorizontal:
					pheight -= 2
					y += 1
				case tui.BorderVertical:
					pwidth -= (1 + bw) * 2
					x += 1 + bw
				}
				if len(t.scrollbar) > 0 && !previewOpts.border.HasRight() {
					// Need a column to show scrollbar
					pwidth -= 1
				}
				pwidth = util.Max(0, pwidth)
				pheight = util.Max(0, pheight)
				t.pwindow = t.tui.NewWindow(y, x, pwidth, pheight, true, noBorder)
				if !hadPreviewWindow {
					t.pwindow.Erase()
				}
			}
			verticalPad := 2
			minPreviewHeight := 3
			switch previewOpts.border {
			case tui.BorderNone, tui.BorderVertical, tui.BorderLeft, tui.BorderRight:
				verticalPad = 0
				minPreviewHeight = 1
			case tui.BorderTop, tui.BorderBottom:
				verticalPad = 1
				minPreviewHeight = 2
			}
			switch previewOpts.position {
			case posUp, posDown:
				pheight := calculateSize(height, previewOpts.size, minHeight, minPreviewHeight, verticalPad)
				if hasThreshold && pheight < previewOpts.threshold {
					t.activePreviewOpts = previewOpts.alternative
					if forcePreview {
						previewOpts.alternative.hidden = false
					}
					if !previewOpts.alternative.hidden {
						resizePreviewWindows(previewOpts.alternative)
					}
					return
				}
				if forcePreview {
					previewOpts.hidden = false
				}
				if previewOpts.hidden {
					return
				}
				if previewOpts.position == posUp {
					t.window = t.tui.NewWindow(
						marginInt[0]+pheight, marginInt[3], width, height-pheight, false, noBorder)
					createPreviewWindow(marginInt[0], marginInt[3], width, pheight)
				} else {
					t.window = t.tui.NewWindow(
						marginInt[0], marginInt[3], width, height-pheight, false, noBorder)
					createPreviewWindow(marginInt[0]+height-pheight, marginInt[3], width, pheight)
				}
			case posLeft, posRight:
				pwidth := calculateSize(width, previewOpts.size, minWidth, 5, 4)
				if hasThreshold && pwidth < previewOpts.threshold {
					t.activePreviewOpts = previewOpts.alternative
					if forcePreview {
						previewOpts.alternative.hidden = false
					}
					if !previewOpts.alternative.hidden {
						resizePreviewWindows(previewOpts.alternative)
					}
					return
				}
				if forcePreview {
					previewOpts.hidden = false
				}
				if previewOpts.hidden {
					return
				}
				if previewOpts.position == posLeft {
					// Put scrollbar closer to the right border for consistent look
					if t.borderShape.HasRight() {
						width++
					}
					// Add a 1-column margin between the preview window and the main window
					t.window = t.tui.NewWindow(
						marginInt[0], marginInt[3]+pwidth+1, width-pwidth-1, height, false, noBorder)

					// Clear characters on the margin
					//   fzf --bind 'space:preview(seq 100)' --preview-window left,1
					for y := 0; y < height; y++ {
						t.window.Move(y, -1)
						t.window.Print(" ")
					}

					createPreviewWindow(marginInt[0], marginInt[3], pwidth, height)
				} else {
					t.window = t.tui.NewWindow(
						marginInt[0], marginInt[3], width-pwidth, height, false, noBorder)
					// NOTE: fzf --preview 'cat {}' --preview-window border-left --border
					x := marginInt[3] + width - pwidth
					if !previewOpts.border.HasRight() && t.borderShape.HasRight() {
						pwidth++
					}
					createPreviewWindow(marginInt[0], x, pwidth, height)
				}
			}
		}
		resizePreviewWindows(&t.previewOpts)
	} else {
		t.activePreviewOpts = &t.previewOpts
	}

	// Without preview window
	if t.window == nil {
		if t.borderShape.HasRight() {
			// Put scrollbar closer to the right border for consistent look
			width++
		}
		t.window = t.tui.NewWindow(
			marginInt[0],
			marginInt[3],
			width,
			height, false, noBorder)
	}

	// Print border label
	t.printLabel(t.border, t.borderLabel, t.borderLabelOpts, t.borderLabelLen, t.borderShape, false)
	t.printLabel(t.pborder, t.previewLabel, t.previewLabelOpts, t.previewLabelLen, t.previewOpts.border, false)
}

func (t *Terminal) printLabel(window tui.Window, render labelPrinter, opts labelOpts, length int, borderShape tui.BorderShape, redrawBorder bool) {
	if window == nil {
		return
	}

	switch borderShape {
	case tui.BorderHorizontal, tui.BorderTop, tui.BorderBottom, tui.BorderRounded, tui.BorderSharp, tui.BorderBold, tui.BorderBlock, tui.BorderThinBlock, tui.BorderDouble:
		if redrawBorder {
			window.DrawHBorder()
		}
		if render == nil {
			return
		}
		var col int
		if opts.column == 0 {
			col = util.Max(0, (window.Width()-length)/2)
		} else if opts.column < 0 {
			col = util.Max(0, window.Width()+opts.column+1-length)
		} else {
			col = util.Min(opts.column-1, window.Width()-length)
		}
		row := 0
		if borderShape == tui.BorderBottom || opts.bottom {
			row = window.Height() - 1
		}
		window.Move(row, col)
		render(window, window.Width())
	}
}

func (t *Terminal) move(y int, x int, clear bool) {
	h := t.window.Height()

	switch t.layout {
	case layoutDefault:
		y = h - y - 1
	case layoutReverseList:
		n := 2 + t.visibleHeaderLines()
		if t.noSeparatorLine() {
			n--
		}
		if y < n {
			y = h - y - 1
		} else {
			y -= n
		}
	}

	if clear {
		t.window.MoveAndClear(y, x)
	} else {
		t.window.Move(y, x)
	}
}

func (t *Terminal) truncateQuery() {
	t.input, _ = t.trimRight(t.input, maxPatternLength)
	t.cx = util.Constrain(t.cx, 0, len(t.input))
}

func (t *Terminal) updatePromptOffset() ([]rune, []rune) {
	maxWidth := util.Max(1, t.window.Width()-t.promptLen-1)

	_, overflow := t.trimLeft(t.input[:t.cx], maxWidth)
	minOffset := int(overflow)
	maxOffset := minOffset + (maxWidth-util.Max(0, maxWidth-t.cx))/2
	t.xoffset = util.Constrain(t.xoffset, minOffset, maxOffset)
	before, _ := t.trimLeft(t.input[t.xoffset:t.cx], maxWidth)
	beforeLen := t.displayWidth(before)
	after, _ := t.trimRight(t.input[t.cx:], maxWidth-beforeLen)
	afterLen := t.displayWidth(after)
	t.queryLen = [2]int{beforeLen, afterLen}
	return before, after
}

func (t *Terminal) promptLine() int {
	if t.headerFirst {
		max := t.window.Height() - 1
		if !t.noSeparatorLine() {
			max--
		}
		return util.Min(t.visibleHeaderLines(), max)
	}
	return 0
}

func (t *Terminal) placeCursor() {
	t.move(t.promptLine(), t.promptLen+t.queryLen[0], false)
}

func (t *Terminal) printPrompt() {
	t.prompt()

	before, after := t.updatePromptOffset()
	color := tui.ColInput
	if t.paused {
		color = tui.ColDisabled
	}
	t.window.CPrint(color, string(before))
	t.window.CPrint(color, string(after))
}

func (t *Terminal) trimMessage(message string, maxWidth int) string {
	if len(message) <= maxWidth {
		return message
	}
	runes, _ := t.trimRight([]rune(message), maxWidth-2)
	return string(runes) + strings.Repeat(".", util.Constrain(maxWidth, 0, 2))
}

func (t *Terminal) printInfo() {
	pos := 0
	line := t.promptLine()
	move := func(y int, x int, clear bool) {
		t.move(y, x, clear)
		t.markOtherLine(y)
	}
	printSpinner := func() {
		if t.reading {
			duration := int64(spinnerDuration)
			idx := (time.Now().UnixNano() % (duration * int64(len(t.spinner)))) / duration
			t.window.CPrint(tui.ColSpinner, t.spinner[idx])
		} else {
			t.window.Print(" ") // Clear spinner
		}
	}
	printInfoPrefix := func() {
		str := t.infoPrefix
		maxWidth := t.window.Width() - pos
		width := util.StringWidth(str)
		if width > maxWidth {
			trimmed, _ := t.trimRight([]rune(str), maxWidth)
			str = string(trimmed)
			width = maxWidth
		}
		move(line, pos, t.separatorLen == 0)
		if t.reading {
			t.window.CPrint(tui.ColSpinner, str)
		} else {
			t.window.CPrint(tui.ColPrompt, str)
		}
		pos += width
	}
	printSeparator := func(fillLength int, pad bool) {
		if t.separatorLen > 0 {
			t.separator(t.window, fillLength)
			t.window.Print(" ")
		} else if pad {
			t.window.Print(strings.Repeat(" ", fillLength+1))
		}
	}
	switch t.infoStyle {
	case infoDefault:
		move(line+1, 0, t.separatorLen == 0)
		printSpinner()
		t.window.Print(" ") // Margin
		pos = 2
	case infoRight:
		move(line+1, 0, false)
	case infoInlineRight:
		pos = t.promptLen + t.queryLen[0] + t.queryLen[1] + 1
	case infoInline:
		pos = t.promptLen + t.queryLen[0] + t.queryLen[1] + 1
		printInfoPrefix()
	case infoHidden:
		if t.separatorLen > 0 {
			move(line+1, 0, false)
			printSeparator(t.window.Width()-1, false)
		}
		return
	}

	found := t.merger.Length()
	total := util.Max(found, t.count)
	output := fmt.Sprintf("%d/%d", found, total)
	if t.toggleSort {
		if t.sort {
			output += " +S"
		} else {
			output += " -S"
		}
	}
	switch t.track {
	case trackEnabled:
		output += " +T"
	case trackCurrent:
		output += " +t"
	}
	if t.multi > 0 {
		if t.multi == maxMulti {
			output += fmt.Sprintf(" (%d)", len(t.selected))
		} else {
			output += fmt.Sprintf(" (%d/%d)", len(t.selected), t.multi)
		}
	}
	if t.progress > 0 && t.progress < 100 {
		output += fmt.Sprintf(" (%d%%)", t.progress)
	}
	if t.failed != nil && t.count == 0 {
		output = fmt.Sprintf("[Command failed: %s]", *t.failed)
	}

	if t.infoStyle == infoRight {
		maxWidth := t.window.Width()
		if t.reading {
			// Need space for spinner and a margin column
			maxWidth -= 2
		}
		output = t.trimMessage(output, maxWidth)
		fillLength := t.window.Width() - len(output) - 2
		if t.reading {
			if fillLength >= 2 {
				printSeparator(fillLength-2, true)
			}
			printSpinner()
			t.window.Print(" ")
		} else if fillLength >= 0 {
			printSeparator(fillLength, true)
		}
		t.window.CPrint(tui.ColInfo, output)
		t.window.Print(" ") // Margin
		return
	}

	if t.infoStyle == infoInlineRight {
		if len(t.infoPrefix) == 0 {
			move(line, pos, false)
			newPos := util.Max(pos, t.window.Width()-util.StringWidth(output)-3)
			t.window.Print(strings.Repeat(" ", newPos-pos))
			pos = newPos
			if pos < t.window.Width() {
				printSpinner()
				pos++
			}
			if pos < t.window.Width()-1 {
				t.window.Print(" ")
				pos++
			}
		} else {
			pos = util.Max(pos, t.window.Width()-util.StringWidth(output)-util.StringWidth(t.infoPrefix)-1)
			printInfoPrefix()
		}
	}

	maxWidth := t.window.Width() - pos
	output = t.trimMessage(output, maxWidth)
	t.window.CPrint(tui.ColInfo, output)

	if t.infoStyle == infoInlineRight {
		if t.separatorLen > 0 {
			move(line+1, 0, false)
			printSeparator(t.window.Width()-1, false)
		}
		return
	}

	fillLength := maxWidth - len(output) - 2
	if fillLength > 0 {
		t.window.CPrint(tui.ColSeparator, " ")
		printSeparator(fillLength, false)
	}
}

func (t *Terminal) printHeader() {
	if t.visibleHeaderLines() == 0 {
		return
	}
	max := t.window.Height()
	if t.headerFirst {
		max--
		if !t.noSeparatorLine() {
			max--
		}
	}
	var state *ansiState
	needReverse := false
	switch t.layout {
	case layoutDefault, layoutReverseList:
		needReverse = true
	}
	for idx, lineStr := range append(append([]string{}, t.header0...), t.header...) {
		line := idx
		if needReverse && idx < len(t.header0) {
			line = len(t.header0) - idx - 1
		}
		if !t.headerFirst {
			line++
			if !t.noSeparatorLine() {
				line++
			}
		}
		if line >= max {
			continue
		}
		trimmed, colors, newState := extractColor(lineStr, state, nil)
		state = newState
		item := &Item{
			text:   util.ToChars([]byte(trimmed)),
			colors: colors}

		t.printHighlighted(Result{item: item},
			tui.ColHeader, tui.ColHeader, false, false, line, line, true,
			func(markerClass) { t.window.Print("  ") }, nil)
	}
}

func (t *Terminal) printList() {
	t.constrain()
	barLength, barStart := t.getScrollbar()

	maxy := t.maxItems() - 1
	count := t.merger.Length() - t.offset

	// Start line
	startLine := 2 + t.visibleHeaderLines()
	if t.noSeparatorLine() {
		startLine--
	}
	maxy += startLine

	barRange := [2]int{startLine + barStart, startLine + barStart + barLength}
	for line, itemCount := startLine, 0; line <= maxy; line, itemCount = line+1, itemCount+1 {
		if itemCount < count {
			item := t.merger.Get(itemCount + t.offset)
			line = t.printItem(item, line, maxy, itemCount, itemCount == t.cy-t.offset, barRange)
		} else if !t.prevLines[line].empty {
			t.move(line, 0, true)
			t.markEmptyLine(line)
			// If the screen is not filled with the list in non-multi-line mode,
			// scrollbar is not visible at all. But in multi-line mode, we may need
			// to redraw the scrollbar character at the end.
			if t.multiLine {
				t.prevLines[line].hasBar = t.printBar(line, true, barRange)
			}
		}
	}
}

func (t *Terminal) printBar(lineNum int, forceRedraw bool, barRange [2]int) bool {
	hasBar := lineNum >= barRange[0] && lineNum < barRange[1]
	if len(t.scrollbar) > 0 && (hasBar != t.prevLines[lineNum].hasBar || forceRedraw) {
		t.move(lineNum, t.window.Width()-1, true)
		if hasBar {
			t.window.CPrint(tui.ColScrollbar, t.scrollbar)
		}
	}
	return hasBar
}

func (t *Terminal) printItem(result Result, line int, maxLine int, index int, current bool, barRange [2]int) int {
	item := result.item
	_, selected := t.selected[item.Index()]
	label := ""
	if t.jumping != jumpDisabled {
		if index < len(t.jumpLabels) {
			// Striped
			current = index%2 == 0
			label = t.jumpLabels[index:index+1] + strings.Repeat(" ", t.pointerLen-1)
		}
	} else if current {
		label = t.pointer
	}

	// Avoid unnecessary redraw
	newLine := itemLine{firstLine: line, cy: index + t.offset, current: current, selected: selected, label: label,
		result: result, queryLen: len(t.input), width: 0, hasBar: line >= barRange[0] && line < barRange[1]}
	prevLine := t.prevLines[line]
	forceRedraw := prevLine.other || prevLine.firstLine != newLine.firstLine
	printBar := func(lineNum int, forceRedraw bool) bool {
		return t.printBar(lineNum, forceRedraw, barRange)
	}

	if !forceRedraw &&
		prevLine.current == newLine.current &&
		prevLine.selected == newLine.selected &&
		prevLine.label == newLine.label &&
		prevLine.queryLen == newLine.queryLen &&
		prevLine.result == newLine.result {
		t.prevLines[line].hasBar = printBar(line, false)
		if !t.multiLine {
			return line
		}
		lines, _ := item.text.NumLines(maxLine - line + 1)
		return line + lines - 1
	}

	maxWidth := t.window.Width() - (t.pointerLen + t.markerLen + 1)
	postTask := func(lineNum int, width int) {
		if (current || selected) && t.highlightLine {
			color := tui.ColSelected
			if current {
				color = tui.ColCurrent
			}
			fillSpaces := maxWidth - width
			if fillSpaces > 0 {
				t.window.CPrint(color, strings.Repeat(" ", fillSpaces))
			}
			newLine.width = maxWidth
		} else {
			fillSpaces := t.prevLines[lineNum].width - width
			if fillSpaces > 0 {
				t.window.Print(strings.Repeat(" ", fillSpaces))
			}
			newLine.width = width
		}
		// When width is 0, line is completely cleared. We need to redraw scrollbar
		newLine.hasBar = printBar(lineNum, forceRedraw || width == 0)
		t.prevLines[lineNum] = newLine
	}

	var finalLineNum int
	markerFor := func(markerClass markerClass) string {
		marker := t.marker
		switch markerClass {
		case markerTop:
			marker = t.markerMultiLine[0]
		case markerMiddle:
			marker = t.markerMultiLine[1]
		case markerBottom:
			marker = t.markerMultiLine[2]
		}
		return marker
	}
	if current {
		preTask := func(marker markerClass) {
			if len(label) == 0 {
				t.window.CPrint(tui.ColCurrentCursorEmpty, t.pointerEmpty)
			} else {
				t.window.CPrint(tui.ColCurrentCursor, label)
			}
			if selected {
				t.window.CPrint(tui.ColCurrentMarker, markerFor(marker))
			} else {
				t.window.CPrint(tui.ColCurrentSelectedEmpty, t.markerEmpty)
			}
		}
		finalLineNum = t.printHighlighted(result, tui.ColCurrent, tui.ColCurrentMatch, true, true, line, maxLine, forceRedraw, preTask, postTask)
	} else {
		preTask := func(marker markerClass) {
			if len(label) == 0 {
				t.window.CPrint(tui.ColCursorEmpty, t.pointerEmpty)
			} else {
				t.window.CPrint(tui.ColCursor, label)
			}
			if selected {
				t.window.CPrint(tui.ColMarker, markerFor(marker))
			} else {
				t.window.Print(t.markerEmpty)
			}
		}
		var base, match tui.ColorPair
		if selected {
			base = tui.ColSelected
			match = tui.ColSelectedMatch
		} else {
			base = tui.ColNormal
			match = tui.ColMatch
		}
		finalLineNum = t.printHighlighted(result, base, match, false, true, line, maxLine, forceRedraw, preTask, postTask)
	}
	return finalLineNum
}

func (t *Terminal) trimRight(runes []rune, width int) ([]rune, bool) {
	// We start from the beginning to handle tab characters
	_, overflowIdx := util.RunesWidth(runes, 0, t.tabstop, width)
	if overflowIdx >= 0 {
		return runes[:overflowIdx], true
	}
	return runes, false
}

func (t *Terminal) displayWidthWithLimit(runes []rune, prefixWidth int, limit int) int {
	width, _ := util.RunesWidth(runes, prefixWidth, t.tabstop, limit)
	return width
}

func (t *Terminal) trimLeft(runes []rune, width int) ([]rune, int32) {
	width = util.Max(0, width)
	var trimmed int32
	// Assume that each rune takes at least one column on screen
	if len(runes) > width+2 {
		diff := len(runes) - width - 2
		trimmed = int32(diff)
		runes = runes[diff:]
	}

	currentWidth := t.displayWidth(runes)

	for currentWidth > width && len(runes) > 0 {
		runes = runes[1:]
		trimmed++
		currentWidth = t.displayWidthWithLimit(runes, 2, width)
	}
	return runes, trimmed
}

func (t *Terminal) overflow(runes []rune, max int) bool {
	return t.displayWidthWithLimit(runes, 0, max) > max
}

func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMatch tui.ColorPair, current bool, match bool, lineNum int, maxLineNum int, forceRedraw bool, preTask func(markerClass), postTask func(int, int)) int {
	var displayWidth int
	item := result.item
	matchOffsets := []Offset{}
	var pos *[]int
	if match && t.merger.pattern != nil {
		_, matchOffsets, pos = t.merger.pattern.MatchItem(item, true, t.slab)
	}
	charOffsets := matchOffsets
	if pos != nil {
		charOffsets = make([]Offset, len(*pos))
		for idx, p := range *pos {
			offset := Offset{int32(p), int32(p + 1)}
			charOffsets[idx] = offset
		}
		sort.Sort(ByOrder(charOffsets))
	}
	allOffsets := result.colorOffsets(charOffsets, t.theme, colBase, colMatch, current)

	from := 0
	text := make([]rune, item.text.Length())
	copy(text, item.text.ToRunes())

	finalLineNum := lineNum
	numItemLines := 1
	cutoff := 0
	overflow := false
	topCutoff := false
	if t.multiLine {
		maxLines := maxLineNum - lineNum + 1
		numItemLines, overflow = item.text.NumLines(maxLines)
		// Cut off the upper lines in the 'default' layout
		if t.layout == layoutDefault && !current && maxLines == numItemLines && overflow {
			actualLines, _ := item.text.NumLines(math.MaxInt32)
			cutoff = actualLines - maxLines
			topCutoff = true
		}
	}
	for lineOffset := 0; from <= len(text) && (lineNum <= maxLineNum || maxLineNum == 0); lineOffset++ {
		finalLineNum = lineNum

		line := text[from:]
		if t.multiLine {
			for idx, r := range text[from:] {
				if r == '\n' {
					line = line[:idx]
					break
				}
			}
		}

		offsets := []colorOffset{}
		for _, offset := range allOffsets {
			if offset.offset[0] >= int32(from) && offset.offset[1] <= int32(from+len(line)) {
				offset.offset[0] -= int32(from)
				offset.offset[1] -= int32(from)
				offsets = append(offsets, offset)
			} else {
				allOffsets = allOffsets[len(offsets):]
				break
			}
		}

		from += len(line) + 1

		if cutoff > 0 {
			cutoff--
			lineOffset--
			continue
		}

		var maxe int
		for _, offset := range offsets {
			if offset.match {
				maxe = util.Max(maxe, int(offset.offset[1]))
			}
		}

		actualLineNum := lineNum
		if t.layout == layoutDefault {
			actualLineNum = (lineNum - lineOffset) + (numItemLines - lineOffset) - 1
		}
		t.move(actualLineNum, 0, forceRedraw)

		if preTask != nil {
			var marker markerClass
			if numItemLines == 1 {
				if !overflow {
					marker = markerSingle
				} else if topCutoff {
					marker = markerBottom
				} else {
					marker = markerTop
				}
			} else {
				if lineOffset == 0 { // First line
					if topCutoff {
						marker = markerMiddle
					} else {
						marker = markerTop
					}
				} else if lineOffset == numItemLines-1 { // Last line
					if topCutoff || !overflow {
						marker = markerBottom
					} else {
						marker = markerMiddle
					}
				} else {
					marker = markerMiddle
				}
			}

			preTask(marker)
		}

		maxWidth := t.window.Width() - (t.pointerLen + t.markerLen + 1)
		ellipsis, ellipsisWidth := util.Truncate(t.ellipsis, maxWidth/2)
		maxe = util.Constrain(maxe+util.Min(maxWidth/2-ellipsisWidth, t.hscrollOff), 0, len(line))
		displayWidth = t.displayWidthWithLimit(line, 0, maxWidth)
		if displayWidth > maxWidth {
			transformOffsets := func(diff int32, rightTrim bool) {
				for idx, offset := range offsets {
					b, e := offset.offset[0], offset.offset[1]
					el := int32(len(ellipsis))
					b += el - diff
					e += el - diff
					b = util.Max32(b, el)
					if rightTrim {
						e = util.Min32(e, int32(maxWidth-ellipsisWidth))
					}
					offsets[idx].offset[0] = b
					offsets[idx].offset[1] = util.Max32(b, e)
				}
			}
			if t.hscroll {
				if t.keepRight && pos == nil {
					trimmed, diff := t.trimLeft(line, maxWidth-ellipsisWidth)
					transformOffsets(diff, false)
					line = append(ellipsis, trimmed...)
				} else if !t.overflow(line[:maxe], maxWidth-ellipsisWidth) {
					// Stri..
					line, _ = t.trimRight(line, maxWidth-ellipsisWidth)
					line = append(line, ellipsis...)
				} else {
					// Stri..
					rightTrim := false
					if t.overflow(line[maxe:], ellipsisWidth) {
						line = append(line[:maxe], ellipsis...)
						rightTrim = true
					}
					// ..ri..
					var diff int32
					line, diff = t.trimLeft(line, maxWidth-ellipsisWidth)

					// Transform offsets
					transformOffsets(diff, rightTrim)
					line = append(ellipsis, line...)
				}
			} else {
				line, _ = t.trimRight(line, maxWidth-ellipsisWidth)
				line = append(line, ellipsis...)

				for idx, offset := range offsets {
					offsets[idx].offset[0] = util.Min32(offset.offset[0], int32(maxWidth-len(ellipsis)))
					offsets[idx].offset[1] = util.Min32(offset.offset[1], int32(maxWidth))
				}
			}
			displayWidth = t.displayWidthWithLimit(line, 0, displayWidth)
		}

		t.printColoredString(t.window, line, offsets, colBase)
		if postTask != nil {
			postTask(actualLineNum, displayWidth)
		} else {
			t.markOtherLine(actualLineNum)
		}
		lineNum += 1
	}

	return finalLineNum
}

func (t *Terminal) printColoredString(window tui.Window, text []rune, offsets []colorOffset, colBase tui.ColorPair) {
	var index int32
	var substr string
	var prefixWidth int
	maxOffset := int32(len(text))
	for _, offset := range offsets {
		b := util.Constrain32(offset.offset[0], index, maxOffset)
		e := util.Constrain32(offset.offset[1], index, maxOffset)

		substr, prefixWidth = t.processTabs(text[index:b], prefixWidth)
		window.CPrint(colBase, substr)

		if b < e {
			substr, prefixWidth = t.processTabs(text[b:e], prefixWidth)
			window.CPrint(offset.color, substr)
		}

		index = e
		if index >= maxOffset {
			break
		}
	}
	if index < maxOffset {
		substr, _ = t.processTabs(text[index:], prefixWidth)
		window.CPrint(colBase, substr)
	}
}

func (t *Terminal) renderPreviewSpinner() {
	numLines := len(t.previewer.lines)
	spin := t.previewer.spinner
	if len(spin) > 0 || t.previewer.scrollable {
		maxWidth := t.pwindow.Width()
		if !t.previewer.scrollable {
			if maxWidth > 0 {
				t.pwindow.Move(0, maxWidth-1)
				t.pwindow.CPrint(tui.ColPreviewSpinner, spin)
			}
		} else {
			offsetString := fmt.Sprintf("%d/%d", t.previewer.offset+1, numLines)
			if len(spin) > 0 {
				spin += " "
				maxWidth -= 2
			}
			offsetRunes, _ := t.trimRight([]rune(offsetString), maxWidth)
			pos := maxWidth - t.displayWidth(offsetRunes)
			t.pwindow.Move(0, pos)
			if maxWidth > 0 {
				t.pwindow.CPrint(tui.ColPreviewSpinner, spin)
				t.pwindow.CPrint(tui.ColInfo.WithAttr(tui.Reverse), string(offsetRunes))
			}
		}
	}
}

func (t *Terminal) renderPreviewArea(unchanged bool) {
	if t.previewed.wipe && t.previewed.version != t.previewer.version {
		t.previewed.wipe = false
		t.pwindow.Erase()
	} else if unchanged {
		t.pwindow.MoveAndClear(0, 0) // Clear scroll offset display
	} else {
		t.previewed.filled = false
		// We don't erase the window here to avoid flickering during scroll.
		// However, tcell renderer uses double-buffering technique and there's no
		// flickering. So we just erase the window and make the rest of the code
		// simpler.
		if !t.pwindow.EraseMaybe() {
			t.pwindow.DrawBorder()
			t.pwindow.Move(0, 0)
		}
	}

	height := t.pwindow.Height()
	body := t.previewer.lines
	headerLines := t.previewOpts.headerLines
	// Do not enable preview header lines if it's value is too large
	if headerLines > 0 && headerLines < util.Min(len(body), height) {
		header := t.previewer.lines[0:headerLines]
		body = t.previewer.lines[headerLines:]
		// Always redraw header
		t.renderPreviewText(height, header, 0, false)
		t.pwindow.MoveAndClear(t.pwindow.Y(), 0)
	}
	t.renderPreviewText(height, body, -t.previewer.offset+headerLines, unchanged)

	if !unchanged {
		t.pwindow.FinishFill()
	}

	if len(t.scrollbar) == 0 {
		return
	}

	effectiveHeight := height - headerLines
	barLength, barStart := getScrollbar(1, len(body), effectiveHeight, util.Min(len(body)-effectiveHeight, t.previewer.offset-headerLines))
	t.renderPreviewScrollbar(headerLines, barLength, barStart)
}

func (t *Terminal) makeImageBorder(width int, top bool) string {
	tl := "┌"
	tr := "┐"
	v := "╎"
	h := "╌"
	if !t.unicode {
		tl = "+"
		tr = "+"
		h = "-"
		v = "|"
	}
	repeat := util.Max(0, width-2)
	if top {
		return tl + strings.Repeat(h, repeat) + tr
	}
	return v + strings.Repeat(" ", repeat) + v
}

func (t *Terminal) renderPreviewText(height int, lines []string, lineNo int, unchanged bool) {
	maxWidth := t.pwindow.Width()
	var ansi *ansiState
	spinnerRedraw := t.pwindow.Y() == 0
	wiped := false
	image := false
	wireframe := false
Loop:
	for _, line := range lines {
		var lbg tui.Color = -1
		if ansi != nil {
			ansi.lbg = -1
		}

		passThroughs := passThroughRegex.FindAllString(line, -1)
		if passThroughs != nil {
			line = passThroughRegex.ReplaceAllString(line, "")
		}
		line = strings.TrimLeft(strings.TrimRight(line, "\r\n"), "\r")

		if lineNo >= height || t.pwindow.Y() == height-1 && t.pwindow.X() > 0 {
			t.previewed.filled = true
			t.previewer.scrollable = true
			break
		} else if lineNo >= 0 {
			x := t.pwindow.X()
			y := t.pwindow.Y()
			if spinnerRedraw && lineNo > 0 {
				spinnerRedraw = false
				t.renderPreviewSpinner()
				t.pwindow.Move(y, x)
			}
			for idx, passThrough := range passThroughs {
				// Handling Sixel/iTerm image
				requiredLines := 0
				isSixel := strings.HasPrefix(passThrough, "\x1bP")
				isItermImage := strings.HasPrefix(passThrough, "\x1b]1337;")
				isImage := isSixel || isItermImage
				if isImage {
					t.previewed.wipe = true
					// NOTE: We don't have a good way to get the height of an iTerm image,
					// so we assume that it requires the full height of the preview
					// window.
					requiredLines = height

					if isSixel && t.termSize.PxHeight > 0 {
						rows := strings.Count(passThrough, "-")
						requiredLines = int(math.Ceil(float64(rows*6*t.termSize.Lines) / float64(t.termSize.PxHeight)))
					}
				}

				// Render wireframe when the image cannot be displayed entirely
				if requiredLines > 0 && y+requiredLines > height {
					top := true
					for ; y < height; y++ {
						t.pwindow.MoveAndClear(y, 0)
						t.pwindow.CFill(tui.ColPreview.Fg(), tui.ColPreview.Bg(), tui.AttrRegular, t.makeImageBorder(maxWidth, top))
						top = false
					}
					wireframe = true
					t.previewed.filled = true
					t.previewer.scrollable = true
					break Loop
				}

				// Clear previous wireframe or any other text
				if (t.previewed.wireframe || isImage && !t.previewed.image) && !wiped {
					wiped = true
					for i := y + 1; i < height; i++ {
						t.pwindow.MoveAndClear(i, 0)
					}
				}
				image = image || isImage
				if idx == 0 {
					t.pwindow.MoveAndClear(y, x)
				} else {
					t.pwindow.Move(y, x)
				}
				t.tui.PassThrough(passThrough)

				if requiredLines > 0 {
					if y+requiredLines == height {
						t.pwindow.Move(height-1, maxWidth-1)
						t.previewed.filled = true
						break Loop
					}
					t.pwindow.MoveAndClear(y+requiredLines, 0)
				}
			}

			if len(passThroughs) > 0 && len(line) == 0 {
				continue
			}

			var fillRet tui.FillReturn
			prefixWidth := 0
			_, _, ansi = extractColor(line, ansi, func(str string, ansi *ansiState) bool {
				trimmed := []rune(str)
				isTrimmed := false
				if !t.previewOpts.wrap {
					trimmed, isTrimmed = t.trimRight(trimmed, maxWidth-t.pwindow.X())
				}
				str, width := t.processTabs(trimmed, prefixWidth)
				if width > prefixWidth {
					prefixWidth = width
					if t.theme.Colored && ansi != nil && ansi.colored() {
						lbg = ansi.lbg
						fillRet = t.pwindow.CFill(ansi.fg, ansi.bg, ansi.attr, str)
					} else {
						fillRet = t.pwindow.CFill(tui.ColPreview.Fg(), tui.ColPreview.Bg(), tui.AttrRegular, str)
					}
				}
				return !isTrimmed &&
					(fillRet == tui.FillContinue || t.previewOpts.wrap && fillRet == tui.FillNextLine)
			})
			t.previewer.scrollable = t.previewer.scrollable || t.pwindow.Y() == height-1 && t.pwindow.X() == t.pwindow.Width()
			if fillRet == tui.FillNextLine {
				continue
			} else if fillRet == tui.FillSuspend {
				t.previewed.filled = true
				break
			}
			if unchanged && lineNo == 0 {
				break
			}
			if lbg >= 0 {
				t.pwindow.CFill(-1, lbg, tui.AttrRegular,
					strings.Repeat(" ", t.pwindow.Width()-t.pwindow.X())+"\n")
			} else {
				t.pwindow.Fill("\n")
			}
		}
		lineNo++
	}
	t.previewed.image = image
	t.previewed.wireframe = wireframe
}

func (t *Terminal) renderPreviewScrollbar(yoff int, barLength int, barStart int) {
	height := t.pwindow.Height()
	w := t.pborder.Width()
	redraw := false
	if len(t.previewer.bar) != height {
		redraw = true
		t.previewer.bar = make([]bool, height)
	}
	xshift := -1 - t.borderWidth
	if !t.previewOpts.border.HasRight() {
		xshift = -1
	}
	yshift := 1
	if !t.previewOpts.border.HasTop() {
		yshift = 0
	}
	for i := yoff; i < height; i++ {
		x := w + xshift
		y := i + yshift

		// Avoid unnecessary redraws
		bar := i >= yoff+barStart && i < yoff+barStart+barLength
		if !redraw && bar == t.previewer.bar[i] && !t.tui.NeedScrollbarRedraw() {
			continue
		}

		t.previewer.bar[i] = bar
		t.pborder.Move(y, x)
		if i >= yoff+barStart && i < yoff+barStart+barLength {
			t.pborder.CPrint(tui.ColPreviewScrollbar, t.previewScrollbar)
		} else {
			t.pborder.CPrint(tui.ColPreviewScrollbar, " ")
		}
	}
}

func (t *Terminal) printPreview() {
	if !t.hasPreviewWindow() || t.pwindow.Height() == 0 {
		return
	}
	numLines := len(t.previewer.lines)
	height := t.pwindow.Height()
	unchanged := (t.previewed.filled || numLines == t.previewed.numLines) &&
		t.previewer.version == t.previewed.version &&
		t.previewer.offset == t.previewed.offset
	t.previewer.scrollable = t.previewer.offset > t.previewOpts.headerLines || numLines > height
	t.renderPreviewArea(unchanged)
	t.renderPreviewSpinner()
	t.previewed.numLines = numLines
	t.previewed.version = t.previewer.version
	t.previewed.offset = t.previewer.offset
}

func (t *Terminal) printPreviewDelayed() {
	if !t.hasPreviewWindow() || len(t.previewer.lines) > 0 && t.previewed.version == t.previewer.version {
		return
	}

	t.previewer.scrollable = false
	t.renderPreviewArea(true)

	message := t.trimMessage("Loading ..", t.pwindow.Width())
	pos := t.pwindow.Width() - len(message)
	t.pwindow.Move(0, pos)
	t.pwindow.CPrint(tui.ColInfo.WithAttr(tui.Reverse), message)
}

func (t *Terminal) processTabs(runes []rune, prefixWidth int) (string, int) {
	var strbuf strings.Builder
	l := prefixWidth
	gr := uniseg.NewGraphemes(string(runes))
	for gr.Next() {
		rs := gr.Runes()
		str := string(rs)
		var w int
		if len(rs) == 1 && rs[0] == '\t' {
			w = t.tabstop - l%t.tabstop
			strbuf.WriteString(strings.Repeat(" ", w))
		} else {
			w = util.StringWidth(str)
			strbuf.WriteString(str)
		}
		l += w
	}
	return strbuf.String(), l
}

func (t *Terminal) printAll() {
	t.resizeWindows(t.forcePreview)
	t.printList()
	t.printPrompt()
	t.printInfo()
	t.printHeader()
	t.printPreview()
}

func (t *Terminal) flush() {
	t.placeCursor()
	if !t.suppress {
		windows := make([]tui.Window, 0, 4)
		if t.borderShape != tui.BorderNone {
			windows = append(windows, t.border)
		}
		if t.hasPreviewWindow() {
			if t.pborder != nil {
				windows = append(windows, t.pborder)
			}
			windows = append(windows, t.pwindow)
		}
		windows = append(windows, t.window)
		t.tui.RefreshWindows(windows)
	}
}

func (t *Terminal) delChar() bool {
	if len(t.input) > 0 && t.cx < len(t.input) {
		t.input = append(t.input[:t.cx], t.input[t.cx+1:]...)
		return true
	}
	return false
}

func findLastMatch(pattern string, str string) int {
	rx, err := regexp.Compile(pattern)
	if err != nil {
		return -1
	}
	locs := rx.FindAllStringIndex(str, -1)
	if locs == nil {
		return -1
	}
	prefix := []rune(str[:locs[len(locs)-1][0]])
	return len(prefix)
}

func findFirstMatch(pattern string, str string) int {
	rx, err := regexp.Compile(pattern)
	if err != nil {
		return -1
	}
	loc := rx.FindStringIndex(str)
	if loc == nil {
		return -1
	}
	prefix := []rune(str[:loc[0]])
	return len(prefix)
}

func copySlice(slice []rune) []rune {
	ret := make([]rune, len(slice))
	copy(ret, slice)
	return ret
}

func (t *Terminal) rubout(pattern string) {
	pcx := t.cx
	after := t.input[t.cx:]
	t.cx = findLastMatch(pattern, string(t.input[:t.cx])) + 1
	t.yanked = copySlice(t.input[t.cx:pcx])
	t.input = append(t.input[:t.cx], after...)
}

func keyMatch(key tui.Event, event tui.Event) bool {
	return event.Type == key.Type && event.Char == key.Char ||
		key.Type == tui.DoubleClick && event.Type == tui.Mouse && event.MouseEvent.Double
}

func parsePlaceholder(match string) (bool, string, placeholderFlags) {
	flags := placeholderFlags{}

	if match[0] == '\\' {
		// Escaped placeholder pattern
		return true, match[1:], flags
	}

	if strings.HasPrefix(match, "{fzf:") {
		// {fzf:*} are not determined by the current item
		flags.forceUpdate = true
		return false, match, flags
	}

	skipChars := 1
	for _, char := range match[1:] {
		switch char {
		case '+':
			flags.plus = true
			skipChars++
		case 's':
			flags.preserveSpace = true
			skipChars++
		case 'n':
			flags.number = true
			skipChars++
		case 'f':
			flags.file = true
			skipChars++
		case 'q':
			flags.forceUpdate = true
			// query flag is not skipped
		}
	}

	matchWithoutFlags := "{" + match[skipChars:]

	return false, matchWithoutFlags, flags
}

func hasPreviewFlags(template string) (slot bool, plus bool, forceUpdate bool) {
	for _, match := range placeholder.FindAllString(template, -1) {
		escaped, _, flags := parsePlaceholder(match)
		if escaped {
			continue
		}
		if flags.plus {
			plus = true
		}
		if flags.forceUpdate {
			forceUpdate = true
		}
		slot = true
	}
	return
}

type replacePlaceholderParams struct {
	template   string
	stripAnsi  bool
	delimiter  Delimiter
	printsep   string
	forcePlus  bool
	query      string
	allItems   []*Item
	lastAction actionType
	prompt     string
	executor   *util.Executor
}

func (t *Terminal) replacePlaceholder(template string, forcePlus bool, input string, list []*Item) (string, []string) {
	return replacePlaceholder(replacePlaceholderParams{
		template:   template,
		stripAnsi:  t.ansi,
		delimiter:  t.delimiter,
		printsep:   t.printsep,
		forcePlus:  forcePlus,
		query:      input,
		allItems:   list,
		lastAction: t.lastAction,
		prompt:     t.promptString,
		executor:   t.executor,
	})
}

func (t *Terminal) evaluateScrollOffset() int {
	if t.pwindow == nil {
		return 0
	}

	// We only need the current item to calculate the scroll offset
	replaced, tempFiles := t.replacePlaceholder(t.previewOpts.scroll, false, "", []*Item{t.currentItem(), nil})
	removeFiles(tempFiles)
	offsetExpr := offsetTrimCharsRegex.ReplaceAllString(replaced, "")

	atoi := func(s string) int {
		n, e := strconv.Atoi(s)
		if e != nil {
			return 0
		}
		return n
	}

	base := -1
	height := util.Max(0, t.pwindow.Height()-t.previewOpts.headerLines)
	for _, component := range offsetComponentRegex.FindAllString(offsetExpr, -1) {
		if strings.HasPrefix(component, "-/") {
			component = component[1:]
		}
		if component[0] == '/' {
			denom := atoi(component[1:])
			if denom != 0 {
				base -= height / denom
			}
			break
		}
		base += atoi(component)
	}
	return util.Max(0, base)
}

func replacePlaceholder(params replacePlaceholderParams) (string, []string) {
	tempFiles := []string{}
	current := params.allItems[:1]
	selected := params.allItems[1:]
	if current[0] == nil {
		current = []*Item{}
	}
	if selected[0] == nil {
		selected = []*Item{}
	}

	// replace placeholders one by one
	replaced := placeholder.ReplaceAllStringFunc(params.template, func(match string) string {
		escaped, match, flags := parsePlaceholder(match)

		// this function implements the effects a placeholder has on items
		var replace func(*Item) string

		// placeholder types (escaped, query type, item type, token type)
		switch {
		case escaped:
			return match
		case match == "{q}" || match == "{fzf:query}":
			return params.executor.QuoteEntry(params.query)
		case match == "{}":
			replace = func(item *Item) string {
				switch {
				case flags.number:
					n := item.text.Index
					if n == minItem.Index() {
						// NOTE: Item index should normally be positive, but if there's no
						// match, it will be set to math.MinInt32, and we don't want to
						// show that value. However, int32 can overflow, especially when
						// `--tail` is used with an endless input stream, and the index of
						// an item actually can be math.MinInt32. In that case, you're
						// getting an incorrect value, but we're going to ignore that for
						// now.
						return "''"
					}
					return strconv.Itoa(int(n))
				case flags.file:
					return item.AsString(params.stripAnsi)
				default:
					return params.executor.QuoteEntry(item.AsString(params.stripAnsi))
				}
			}
		case match == "{fzf:action}":
			return params.lastAction.Name()
		case match == "{fzf:prompt}":
			return params.executor.QuoteEntry(params.prompt)
		default:
			// token type and also failover (below)
			rangeExpressions := strings.Split(match[1:len(match)-1], ",")
			ranges := make([]Range, len(rangeExpressions))
			for idx, s := range rangeExpressions {
				r, ok := ParseRange(&s) // ellipsis (x..y) and shorthand (x..x) range syntax
				if !ok {
					// Invalid expression, just return the original string in the template
					return match
				}
				ranges[idx] = r
			}

			replace = func(item *Item) string {
				tokens := Tokenize(item.AsString(params.stripAnsi), params.delimiter)
				trans := Transform(tokens, ranges)
				str := joinTokens(trans)

				// trim the last delimiter
				if params.delimiter.str != nil {
					str = strings.TrimSuffix(str, *params.delimiter.str)
				} else if params.delimiter.regex != nil {
					delims := params.delimiter.regex.FindAllStringIndex(str, -1)
					// make sure the delimiter is at the very end of the string
					if len(delims) > 0 && delims[len(delims)-1][1] == len(str) {
						str = str[:delims[len(delims)-1][0]]
					}
				}

				if !flags.preserveSpace {
					str = strings.TrimSpace(str)
				}
				if !flags.file {
					str = params.executor.QuoteEntry(str)
				}
				return str
			}
		}

		// apply 'replace' function over proper set of items and return result

		items := current
		if flags.plus || params.forcePlus {
			items = selected
		}
		replacements := make([]string, len(items))

		for idx, item := range items {
			replacements[idx] = replace(item)
		}

		if flags.file {
			file := WriteTemporaryFile(replacements, params.printsep)
			tempFiles = append(tempFiles, file)
			return file
		}
		return strings.Join(replacements, " ")
	})

	return replaced, tempFiles
}

func (t *Terminal) fullRedraw() {
	t.tui.Clear()
	t.tui.Refresh()
	t.printAll()
}

func (t *Terminal) executeCommand(template string, forcePlus bool, background bool, capture bool, firstLineOnly bool) string {
	line := ""
	valid, list := t.buildPlusList(template, forcePlus)
	// 'capture' is used for transform-* and we don't want to
	// return an empty string in those cases
	if !valid && !capture {
		return line
	}
	command, tempFiles := t.replacePlaceholder(template, forcePlus, string(t.input), list)
	cmd := t.executor.ExecCommand(command, false)
	cmd.Env = t.environ()
	t.executing.Set(true)
	if !background {
		// Open a separate handle for tty input
		if in, _ := tui.TtyIn(); in != nil {
			cmd.Stdin = in
			if in != os.Stdin {
				defer in.Close()
			}
		}

		cmd.Stdout = os.Stdout
		if !util.IsTty(os.Stdout) {
			if out, _ := tui.TtyOut(); out != nil {
				cmd.Stdout = out
				defer out.Close()
			}
		}

		cmd.Stderr = os.Stderr
		if !util.IsTty(os.Stderr) {
			if out, _ := tui.TtyOut(); out != nil {
				cmd.Stderr = out
				defer out.Close()
			}
		}

		t.mutex.Unlock()
		t.uiMutex.Lock()
		t.tui.Pause(true)
		cmd.Run()
		t.tui.Resume(true, false)
		t.mutex.Lock()
		t.fullRedraw()
		t.flush()
		t.uiMutex.Unlock()
	} else {
		t.mutex.Unlock()
		t.uiMutex.Lock()
		if capture {
			out, _ := cmd.StdoutPipe()
			reader := bufio.NewReader(out)
			cmd.Start()
			if firstLineOnly {
				line, _ = reader.ReadString('\n')
				line = strings.TrimRight(line, "\r\n")
			} else {
				bytes, _ := io.ReadAll(reader)
				line = string(bytes)
			}
			cmd.Wait()
		} else {
			cmd.Run()
		}
		t.mutex.Lock()
		t.uiMutex.Unlock()
	}
	t.executing.Set(false)
	removeFiles(tempFiles)
	return line
}

func (t *Terminal) hasPreviewer() bool {
	return t.previewBox != nil
}

func (t *Terminal) needPreviewWindow() bool {
	return t.hasPreviewer() && len(t.previewOpts.command) > 0 && t.previewOpts.Visible()
}

// Check if previewer is currently in action (invisible previewer with size 0 or visible previewer)
func (t *Terminal) canPreview() bool {
	return t.hasPreviewer() && (!t.previewOpts.Visible() && !t.previewOpts.hidden || t.hasPreviewWindow())
}

func (t *Terminal) hasPreviewWindow() bool {
	return t.pwindow != nil
}

func (t *Terminal) currentItem() *Item {
	cnt := t.merger.Length()
	if t.cy >= 0 && cnt > 0 && cnt > t.cy {
		return t.merger.Get(t.cy).item
	}
	return nil
}

func (t *Terminal) buildPlusList(template string, forcePlus bool) (bool, []*Item) {
	current := t.currentItem()
	slot, plus, forceUpdate := hasPreviewFlags(template)
	if !(!slot || forceUpdate || (forcePlus || plus) && len(t.selected) > 0) {
		return current != nil, []*Item{current, current}
	}

	// We would still want to update preview window even if there is no match if
	//   1. the command template contains {q}
	//   2. or it contains {+} and we have more than one item already selected.
	// To do so, we pass an empty Item instead of nil to trigger an update.
	if current == nil {
		current = &minItem
	}

	var sels []*Item
	if len(t.selected) == 0 {
		sels = []*Item{current, current}
	} else {
		sels = make([]*Item, len(t.selected)+1)
		sels[0] = current
		for i, sel := range t.sortSelected() {
			sels[i+1] = sel.item
		}
	}
	return true, sels
}

func (t *Terminal) selectItem(item *Item) bool {
	if len(t.selected) >= t.multi {
		return false
	}
	if _, found := t.selected[item.Index()]; found {
		return true
	}

	t.selected[item.Index()] = selectedItem{time.Now(), item}
	t.version++

	return true
}

func (t *Terminal) selectItemChanged(item *Item) bool {
	if _, found := t.selected[item.Index()]; found {
		return false
	}
	return t.selectItem(item)
}

func (t *Terminal) deselectItem(item *Item) {
	delete(t.selected, item.Index())
	t.version++
}

func (t *Terminal) deselectItemChanged(item *Item) bool {
	if _, found := t.selected[item.Index()]; found {
		t.deselectItem(item)
		return true
	}
	return false
}

func (t *Terminal) toggleItem(item *Item) bool {
	if _, found := t.selected[item.Index()]; !found {
		return t.selectItem(item)
	}
	t.deselectItem(item)
	return true
}

func (t *Terminal) killPreview() {
	select {
	case t.killChan <- true:
	default:
	}
}

func (t *Terminal) cancelPreview() {
	select {
	case t.killChan <- false:
	default:
	}
}

func (t *Terminal) pwindowSize() tui.TermSize {
	if t.pwindow == nil {
		return tui.TermSize{}
	}
	size := tui.TermSize{Lines: t.pwindow.Height(), Columns: t.pwindow.Width()}

	if t.termSize.PxWidth > 0 {
		size.PxWidth = size.Columns * t.termSize.PxWidth / t.termSize.Columns
		size.PxHeight = size.Lines * t.termSize.PxHeight / t.termSize.Lines
	}
	return size
}

func (t *Terminal) currentIndex() int32 {
	if currentItem := t.currentItem(); currentItem != nil {
		return currentItem.Index()
	}
	return minItem.Index()
}

// Loop is called to start Terminal I/O
func (t *Terminal) Loop() error {
	// prof := profile.Start(profile.ProfilePath("/tmp/"))
	fitpad := <-t.startChan
	fit := fitpad.fit
	if fit >= 0 {
		pad := fitpad.pad
		t.tui.Resize(func(termHeight int) int {
			contentHeight := fit + t.extraLines()
			if t.needPreviewWindow() {
				if t.previewOpts.aboveOrBelow() {
					if t.previewOpts.size.percent {
						newContentHeight := int(float64(contentHeight) * 100. / (100. - t.previewOpts.size.size))
						contentHeight = util.Max(contentHeight+1+borderLines(t.previewOpts.border), newContentHeight)
					} else {
						contentHeight += int(t.previewOpts.size.size) + borderLines(t.previewOpts.border)
					}
				} else {
					// Minimum height if preview window can appear
					contentHeight = util.Max(contentHeight, 1+borderLines(t.previewOpts.border))
				}
			}
			return util.Min(termHeight, contentHeight+pad)
		})
	}

	// Context
	ctx, cancel := context.WithCancel(context.Background())

	{ // Late initialization
		intChan := make(chan os.Signal, 1)
		signal.Notify(intChan, os.Interrupt, syscall.SIGTERM)
		go func() {
			for {
				select {
				case <-ctx.Done():
					return
				case s := <-intChan:
					// Don't quit by SIGINT while executing because it should be for the executing command and not for fzf itself
					if !(s == os.Interrupt && t.executing.Get()) {
						t.reqBox.Set(reqQuit, nil)
					}
				}
			}
		}()

		contChan := make(chan os.Signal, 1)
		notifyOnCont(contChan)
		go func() {
			for {
				select {
				case <-ctx.Done():
					return
				case <-contChan:
					t.reqBox.Set(reqReinit, nil)
				}
			}
		}()

		if !t.tui.ShouldEmitResizeEvent() {
			resizeChan := make(chan os.Signal, 1)
			notifyOnResize(resizeChan) // Non-portable
			go func() {
				for {
					select {
					case <-ctx.Done():
						return
					case <-resizeChan:
						t.reqBox.Set(reqResize, nil)
					}
				}
			}()
		}

		t.mutex.Lock()
		if err := t.initFunc(); err != nil {
			t.mutex.Unlock()
			cancel()
			t.eventBox.Set(EvtQuit, quitSignal{ExitError, err})
			return err
		}
		t.termSize = t.tui.Size()
		t.resizeWindows(false)
		t.window.Erase()
		t.printPrompt()
		t.printInfo()
		t.printHeader()
		t.flush()
		t.mutex.Unlock()
		if t.initDelay > 0 {
			go func() {
				timer := time.NewTimer(t.initDelay)
				<-timer.C
				t.reqBox.Set(reqActivate, nil)
			}()
		}

		// Keep the spinner spinning
		go func() {
			for t.running.Get() {
				t.mutex.Lock()
				reading := t.reading
				t.mutex.Unlock()
				time.Sleep(spinnerDuration)
				if reading {
					t.reqBox.Set(reqInfo, nil)
				}
			}
		}()
	}

	if t.hasPreviewer() {
		go func() {
			var version int64
			stop := false
			for {
				var items []*Item
				var commandTemplate string
				var pwindow tui.Window
				var pwindowSize tui.TermSize
				var env []string
				initialOffset := 0
				t.previewBox.Wait(func(events *util.Events) {
					for req, value := range *events {
						switch req {
						case reqQuit:
							stop = true
							return
						case reqPreviewEnqueue:
							request := value.(previewRequest)
							commandTemplate = request.template
							initialOffset = request.scrollOffset
							items = request.list
							pwindow = request.pwindow
							pwindowSize = request.pwindowSize
							env = request.env
						}
					}
					events.Clear()
				})
				if stop {
					break
				}
				version++
				// We don't display preview window if no match
				if items[0] != nil {
					_, query := t.Input()
					command, tempFiles := t.replacePlaceholder(commandTemplate, false, string(query), items)
					cmd := t.executor.ExecCommand(command, true)
					if pwindowSize.Lines > 0 {
						lines := fmt.Sprintf("LINES=%d", pwindowSize.Lines)
						columns := fmt.Sprintf("COLUMNS=%d", pwindowSize.Columns)
						env = append(env, lines)
						env = append(env, "FZF_PREVIEW_"+lines)
						env = append(env, columns)
						env = append(env, "FZF_PREVIEW_"+columns)
						env = append(env, fmt.Sprintf("FZF_PREVIEW_TOP=%d", t.tui.Top()+pwindow.Top()))
						env = append(env, fmt.Sprintf("FZF_PREVIEW_LEFT=%d", pwindow.Left()))
					}
					cmd.Env = env

					out, _ := cmd.StdoutPipe()
					cmd.Stderr = cmd.Stdout
					reader := bufio.NewReader(out)
					eofChan := make(chan bool)
					finishChan := make(chan bool, 1)
					err := cmd.Start()
					if err == nil {
						reapChan := make(chan bool)
						lineChan := make(chan eachLine)
						// Goroutine 1 reads process output
						go func() {
							for {
								line, err := reader.ReadString('\n')
								lineChan <- eachLine{line, err}
								if err != nil {
									break
								}
							}
							eofChan <- true
						}()

						// Goroutine 2 periodically requests rendering
						rendered := util.NewAtomicBool(false)
						go func(version int64) {
							lines := []string{}
							spinner := makeSpinner(t.unicode)
							spinnerIndex := -1 // Delay initial rendering by an extra tick
							ticker := time.NewTicker(previewChunkDelay)
							offset := initialOffset
						Loop:
							for {
								select {
								case <-ticker.C:
									if len(lines) > 0 && len(lines) >= initialOffset {
										if spinnerIndex >= 0 {
											spin := spinner[spinnerIndex%len(spinner)]
											t.reqBox.Set(reqPreviewDisplay, previewResult{version, lines, offset, spin})
											rendered.Set(true)
											offset = -1
										}
										spinnerIndex++
									}
								case eachLine := <-lineChan:
									line := eachLine.line
									err := eachLine.err
									if len(line) > 0 {
										clearIndex := strings.Index(line, clearCode)
										if clearIndex >= 0 {
											lines = []string{}
											line = line[clearIndex+len(clearCode):]
											version--
											offset = 0
										}
										lines = append(lines, line)
									}
									if err != nil {
										t.reqBox.Set(reqPreviewDisplay, previewResult{version, lines, offset, ""})
										rendered.Set(true)
										break Loop
									}
								}
							}
							ticker.Stop()
							reapChan <- true
						}(version)

						// Goroutine 3 is responsible for cancelling running preview command
						go func(version int64) {
							timer := time.NewTimer(previewDelayed)
						Loop:
							for {
								select {
								case <-ctx.Done():
									break Loop
								case <-timer.C:
									t.reqBox.Set(reqPreviewDelayed, version)
								case immediately := <-t.killChan:
									if immediately {
										util.KillCommand(cmd)
									} else {
										// We can immediately kill a long-running preview program
										// once we started rendering its partial output
										delay := previewCancelWait
										if rendered.Get() {
											delay = 0
										}
										timer := time.NewTimer(delay)
										select {
										case <-timer.C:
											util.KillCommand(cmd)
										case <-finishChan:
										}
										timer.Stop()
									}
									break Loop
								case <-finishChan:
									break Loop
								}
							}
							timer.Stop()
							reapChan <- true
						}(version)

						<-eofChan          // Goroutine 1 finished
						cmd.Wait()         // NOTE: We should not call Wait before EOF
						finishChan <- true // Tell Goroutine 3 to stop
						<-reapChan         // Goroutine 2 and 3 finished
						<-reapChan
						removeFiles(tempFiles)
					} else {
						// Failed to start the command. Report the error immediately.
						t.reqBox.Set(reqPreviewDisplay, previewResult{version, []string{err.Error()}, 0, ""})
					}
				} else {
					t.reqBox.Set(reqPreviewDisplay, previewResult{version, nil, 0, ""})
				}
			}
		}()
	}

	refreshPreview := func(command string) {
		if len(command) > 0 && t.canPreview() {
			_, list := t.buildPlusList(command, false)
			t.cancelPreview()
			t.previewBox.Set(reqPreviewEnqueue, previewRequest{command, t.pwindow, t.pwindowSize(), t.evaluateScrollOffset(), list, t.environ()})
		}
	}

	go func() { // Render loop
		var focusedIndex = minItem.Index()
		var version int64 = -1
		running := true
		code := ExitError
		exit := func(getCode func() int) {
			if t.hasPreviewer() {
				t.previewBox.Set(reqQuit, nil)
			}
			if t.listener != nil {
				t.listener.Close()
			}
			t.tui.Close()
			code = getCode()
			if code <= ExitNoMatch && t.history != nil {
				t.history.append(string(t.input))
			}
			running = false
			t.mutex.Unlock()
		}

		for running {
			t.reqBox.Wait(func(events *util.Events) {
				defer events.Clear()

				// t.uiMutex must be locked first to avoid deadlock. Execute actions
				// will 1. unlock t.mutex to allow GET endpoint and 2. lock t.uiMutex
				// to block rendering during the execution.
				//
				// T1           T2 (good)       |  T1            T2 (bad)
				//               L t.uiMutex    |
				//  L t.mutex                   |   L t.mutex
				//  U t.mutex                   |   U t.mutex
				//               L t.mutex      |                 L t.mutex
				//               U t.mutex      |   L t.uiMutex
				//               U t.uiMutex    |                 L t.uiMutex!!
				//  L t.uiMutex                 |
				//                              |   L t.mutex!!
				//  L t.mutex                   |   U t.uiMutex
				//  U t.uiMutex                 |
				t.uiMutex.Lock()
				t.mutex.Lock()
				for req, value := range *events {
					switch req {
					case reqPrompt:
						t.printPrompt()
						if t.infoStyle == infoInline || t.infoStyle == infoInlineRight {
							t.printInfo()
						}
					case reqInfo:
						t.printInfo()
					case reqList:
						t.printList()
						currentIndex := t.currentIndex()
						focusChanged := focusedIndex != currentIndex
						if focusChanged && t.track == trackCurrent {
							t.track = trackDisabled
							t.printInfo()
						}
						if t.hasFocusActions && focusChanged && currentIndex != t.lastFocus {
							t.lastFocus = currentIndex
							t.eventChan <- tui.Focus.AsEvent()
						}
						if focusChanged || version != t.version {
							version = t.version
							focusedIndex = currentIndex
							refreshPreview(t.previewOpts.command)
						}
					case reqJump:
						if t.merger.Length() == 0 {
							t.jumping = jumpDisabled
						}
						t.printList()
					case reqHeader:
						t.printHeader()
					case reqActivate:
						t.suppress = false
					case reqRedrawBorderLabel:
						t.printLabel(t.border, t.borderLabel, t.borderLabelOpts, t.borderLabelLen, t.borderShape, true)
					case reqRedrawPreviewLabel:
						t.printLabel(t.pborder, t.previewLabel, t.previewLabelOpts, t.previewLabelLen, t.previewOpts.border, true)
					case reqReinit:
						t.tui.Resume(t.fullscreen, t.sigstop)
						t.fullRedraw()
					case reqResize, reqFullRedraw:
						if req == reqResize {
							t.termSize = t.tui.Size()
						}
						wasHidden := t.pwindow == nil
						t.fullRedraw()
						if wasHidden && t.hasPreviewWindow() {
							refreshPreview(t.previewOpts.command)
						}
						if req == reqResize && t.hasResizeActions {
							t.eventChan <- tui.Resize.AsEvent()
						}
					case reqClose:
						exit(func() int {
							if t.output() {
								return ExitOk
							}
							return ExitNoMatch
						})
						return
					case reqPreviewDisplay:
						result := value.(previewResult)
						if t.previewer.version != result.version {
							t.previewer.version = result.version
							t.previewer.following.Force(t.previewOpts.follow)
							if t.previewer.following.Enabled() {
								t.previewer.offset = 0
							}
						}
						t.previewer.lines = result.lines
						t.previewer.spinner = result.spinner
						if t.hasPreviewWindow() && t.previewer.following.Enabled() {
							t.previewer.offset = util.Max(t.previewer.offset, len(t.previewer.lines)-(t.pwindow.Height()-t.previewOpts.headerLines))
						} else if result.offset >= 0 {
							t.previewer.offset = util.Constrain(result.offset, t.previewOpts.headerLines, len(t.previewer.lines)-1)
						}
						t.printPreview()
					case reqPreviewRefresh:
						t.printPreview()
					case reqPreviewDelayed:
						t.previewer.version = value.(int64)
						t.printPreviewDelayed()
					case reqPrintQuery:
						exit(func() int {
							t.printer(string(t.input))
							return ExitOk
						})
						return
					case reqBecome:
						exit(func() int { return ExitBecome })
						return
					case reqQuit:
						exit(func() int { return ExitInterrupt })
						return
					case reqFatal:
						exit(func() int { return ExitError })
						return
					}
				}
				t.flush()
				t.mutex.Unlock()
				t.uiMutex.Unlock()
			})
		}

		t.eventBox.Set(EvtQuit, quitSignal{code, nil})
		t.running.Set(false)
		t.killPreview()
		cancel()
	}()

	looping := true
	barrier := make(chan bool)
	go func() {
		for {
			select {
			case <-ctx.Done():
				return
			case <-barrier:
			}
			select {
			case <-ctx.Done():
				return
			case t.keyChan <- t.tui.GetChar():
			}
		}
	}()
	previewDraggingPos := -1
	barDragging := false
	pbarDragging := false
	wasDown := false
	needBarrier := true

	// If an action is bound to 'start', we're going to process it before reading
	// user input.
	if !t.hasStartActions {
		barrier <- true
		needBarrier = false
	}
	for loopIndex := int64(0); looping; loopIndex++ {
		var newCommand *commandSpec
		var reloadSync bool
		changed := false
		beof := false
		queryChanged := false

		// Special handling of --sync. Activate the interface on the second tick.
		if loopIndex == 1 && t.deferActivation() {
			t.reqBox.Set(reqActivate, nil)
		}

		if loopIndex > 0 && needBarrier {
			barrier <- true
			needBarrier = false
		}

		var event tui.Event
		actions := []*action{}
		select {
		case event = <-t.keyChan:
			needBarrier = true
		case event = <-t.eventChan:
			// Drain channel to process all queued events at once without rendering
			// the intermediate states
		Drain:
			for {
				if eventActions, prs := t.keymap[event]; prs {
					actions = append(actions, eventActions...)
				}
				for {
					select {
					case event = <-t.eventChan:
						continue Drain
					default:
						break Drain
					}
				}
			}
		case serverActions := <-t.serverInputChan:
			event = tui.Invalid.AsEvent()
			if t.listenAddr == nil || t.listenAddr.IsLocal() || t.listenUnsafe {
				actions = serverActions
			} else {
				for _, action := range serverActions {
					if !processExecution(action.t) {
						actions = append(actions, action)
					}
				}
			}
		}

		t.mutex.Lock()
		for key, ret := range t.expect {
			if keyMatch(key, event) {
				t.pressed = ret
				t.mutex.Unlock()
				t.reqBox.Set(reqClose, nil)
				return nil
			}
		}
		previousInput := t.input
		previousCx := t.cx
		t.lastKey = event.KeyName()
		events := []util.EventType{}
		req := func(evts ...util.EventType) {
			for _, event := range evts {
				events = append(events, event)
				if event == reqClose || event == reqQuit {
					looping = false
				}
			}
		}
		updatePreviewWindow := func(forcePreview bool) {
			t.resizeWindows(forcePreview)
			req(reqPrompt, reqList, reqInfo, reqHeader)
		}
		toggle := func() bool {
			current := t.currentItem()
			if current != nil && t.toggleItem(current) {
				req(reqInfo)
				return true
			}
			return false
		}
		scrollPreviewTo := func(newOffset int) {
			if !t.previewer.scrollable {
				return
			}
			numLines := len(t.previewer.lines)
			headerLines := t.previewOpts.headerLines
			if t.previewOpts.cycle {
				offsetRange := numLines - headerLines
				newOffset = ((newOffset-headerLines)+offsetRange)%offsetRange + headerLines
			}
			newOffset = util.Constrain(newOffset, headerLines, numLines-1)
			if t.previewer.offset != newOffset {
				t.previewer.offset = newOffset
				t.previewer.following.Set(t.previewer.offset >= numLines-(t.pwindow.Height()-headerLines))
				req(reqPreviewRefresh)
			}
		}
		scrollPreviewBy := func(amount int) {
			scrollPreviewTo(t.previewer.offset + amount)
		}

		actionsFor := func(eventType tui.EventType) []*action {
			return t.keymap[eventType.AsEvent()]
		}

		var doAction func(*action) bool
		doActions := func(actions []*action) bool {
			for iter := 0; iter <= maxFocusEvents; iter++ {
				currentIndex := t.currentIndex()
				for _, action := range actions {
					if !doAction(action) {
						return false
					}
				}

				if onFocus, prs := t.keymap[tui.Focus.AsEvent()]; prs && iter < maxFocusEvents {
					if newIndex := t.currentIndex(); newIndex != currentIndex {
						t.lastFocus = newIndex
						actions = onFocus
						continue
					}
				}
				break
			}
			return true
		}
		doAction = func(a *action) bool {
			switch a.t {
			case actIgnore, actStart, actClick:
			case actBecome:
				valid, list := t.buildPlusList(a.a, false)
				if valid {
					// We do not remove temp files in this case
					command, _ := t.replacePlaceholder(a.a, false, string(t.input), list)
					t.tui.Close()
					if t.history != nil {
						t.history.append(string(t.input))
					}

					if len(t.proxyScript) > 0 {
						data := strings.Join(append([]string{command}, t.environ()...), "\x00")
						os.WriteFile(t.proxyScript+becomeSuffix, []byte(data), 0600)
						req(reqBecome)
					} else {
						t.executor.Become(t.ttyin, t.environ(), command)
					}
				}
			case actExecute, actExecuteSilent:
				t.executeCommand(a.a, false, a.t == actExecuteSilent, false, false)
			case actExecuteMulti:
				t.executeCommand(a.a, true, false, false, false)
			case actInvalid:
				t.mutex.Unlock()
				return false
			case actTogglePreview, actShowPreview, actHidePreview:
				var act bool
				switch a.t {
				case actShowPreview:
					act = !t.hasPreviewWindow() && len(t.previewOpts.command) > 0
				case actHidePreview:
					act = t.hasPreviewWindow()
				case actTogglePreview:
					act = t.hasPreviewWindow() || len(t.previewOpts.command) > 0
				}
				if act {
					t.activePreviewOpts.Toggle()
					updatePreviewWindow(false)
					if t.canPreview() {
						valid, list := t.buildPlusList(t.previewOpts.command, false)
						if valid {
							t.cancelPreview()
							t.previewBox.Set(reqPreviewEnqueue,
								previewRequest{t.previewOpts.command, t.pwindow, t.pwindowSize(), t.evaluateScrollOffset(), list, t.environ()})
						}
					} else {
						// Discard the preview content so that it won't accidentally appear
						// when preview window is re-enabled and previewDelay is triggered
						t.previewer.lines = nil

						// Also kill the preview process if it's still running
						t.cancelPreview()
					}
				}
			case actTogglePreviewWrap:
				if t.hasPreviewWindow() {
					t.previewOpts.wrap = !t.previewOpts.wrap
					// Reset preview version so that full redraw occurs
					t.previewed.version = 0
					req(reqPreviewRefresh)
				}
			case actTransformPrompt:
				prompt := t.executeCommand(a.a, false, true, true, true)
				t.promptString = prompt
				t.prompt, t.promptLen = t.parsePrompt(prompt)
				req(reqPrompt)
			case actTransformQuery:
				query := t.executeCommand(a.a, false, true, true, true)
				t.input = []rune(query)
				t.cx = len(t.input)
			case actToggleSort:
				t.sort = !t.sort
				changed = true
			case actPreviewTop:
				if t.hasPreviewWindow() {
					scrollPreviewTo(0)
				}
			case actPreviewBottom:
				if t.hasPreviewWindow() {
					scrollPreviewTo(len(t.previewer.lines) - t.pwindow.Height())
				}
			case actPreviewUp:
				if t.hasPreviewWindow() {
					scrollPreviewBy(-1)
				}
			case actPreviewDown:
				if t.hasPreviewWindow() {
					scrollPreviewBy(1)
				}
			case actPreviewPageUp:
				if t.hasPreviewWindow() {
					scrollPreviewBy(-t.pwindow.Height())
				}
			case actPreviewPageDown:
				if t.hasPreviewWindow() {
					scrollPreviewBy(t.pwindow.Height())
				}
			case actPreviewHalfPageUp:
				if t.hasPreviewWindow() {
					scrollPreviewBy(-t.pwindow.Height() / 2)
				}
			case actPreviewHalfPageDown:
				if t.hasPreviewWindow() {
					scrollPreviewBy(t.pwindow.Height() / 2)
				}
			case actBeginningOfLine:
				t.cx = 0
				t.xoffset = 0
			case actBackwardChar:
				if t.cx > 0 {
					t.cx--
				}
			case actPrintQuery:
				req(reqPrintQuery)
			case actChangeMulti:
				multi := t.multi
				if a.a == "" {
					multi = maxMulti
				} else if n, e := strconv.Atoi(a.a); e == nil && n >= 0 {
					multi = n
				}
				if t.multi > 0 && multi != t.multi {
					t.selected = make(map[int32]selectedItem)
					t.version++
				}
				t.multi = multi
				req(reqList, reqInfo)
			case actChangeQuery:
				t.input = []rune(a.a)
				t.cx = len(t.input)
			case actTransformHeader:
				header := t.executeCommand(a.a, false, true, true, false)
				if t.changeHeader(header) {
					req(reqFullRedraw)
				} else {
					req(reqHeader)
				}
			case actChangeHeader:
				if t.changeHeader(a.a) {
					req(reqFullRedraw)
				} else {
					req(reqHeader)
				}
			case actChangeBorderLabel:
				t.borderLabelOpts.label = a.a
				if t.border != nil {
					t.borderLabel, t.borderLabelLen = t.ansiLabelPrinter(a.a, &tui.ColBorderLabel, false)
					req(reqRedrawBorderLabel)
				}
			case actChangePreviewLabel:
				t.previewLabelOpts.label = a.a
				if t.pborder != nil {
					t.previewLabel, t.previewLabelLen = t.ansiLabelPrinter(a.a, &tui.ColPreviewLabel, false)
					req(reqRedrawPreviewLabel)
				}
			case actTransform:
				body := t.executeCommand(a.a, false, true, true, false)
				if actions, err := parseSingleActionList(strings.Trim(body, "\r\n")); err == nil {
					return doActions(actions)
				}
			case actTransformBorderLabel:
				label := t.executeCommand(a.a, false, true, true, true)
				t.borderLabelOpts.label = label
				if t.border != nil {
					t.borderLabel, t.borderLabelLen = t.ansiLabelPrinter(label, &tui.ColBorderLabel, false)
					req(reqRedrawBorderLabel)
				}
			case actTransformPreviewLabel:
				label := t.executeCommand(a.a, false, true, true, true)
				t.previewLabelOpts.label = label
				if t.pborder != nil {
					t.previewLabel, t.previewLabelLen = t.ansiLabelPrinter(label, &tui.ColPreviewLabel, false)
					req(reqRedrawPreviewLabel)
				}
			case actChangePrompt:
				t.promptString = a.a
				t.prompt, t.promptLen = t.parsePrompt(a.a)
				req(reqPrompt)
			case actPreview:
				if !t.hasPreviewWindow() {
					updatePreviewWindow(true)
				}
				refreshPreview(a.a)
			case actRefreshPreview:
				refreshPreview(t.previewOpts.command)
			case actReplaceQuery:
				current := t.currentItem()
				if current != nil {
					t.input = current.text.ToRunes()
					t.cx = len(t.input)
				}
			case actFatal:
				req(reqFatal)
			case actAbort:
				req(reqQuit)
			case actDeleteChar:
				t.delChar()
			case actDeleteCharEof:
				if !t.delChar() && t.cx == 0 {
					req(reqQuit)
				}
			case actEndOfLine:
				t.cx = len(t.input)
			case actCancel:
				if len(t.input) == 0 {
					req(reqQuit)
				} else {
					t.yanked = t.input
					t.input = []rune{}
					t.cx = 0
				}
			case actBackwardDeleteCharEof:
				if len(t.input) == 0 {
					req(reqQuit)
				} else if t.cx > 0 {
					t.input = append(t.input[:t.cx-1], t.input[t.cx:]...)
					t.cx--
				}
			case actForwardChar:
				if t.cx < len(t.input) {
					t.cx++
				}
			case actBackwardDeleteChar:
				beof = len(t.input) == 0
				if t.cx > 0 {
					t.input = append(t.input[:t.cx-1], t.input[t.cx:]...)
					t.cx--
				}
			case actSelectAll:
				if t.multi > 0 {
					for i := 0; i < t.merger.Length(); i++ {
						if !t.selectItem(t.merger.Get(i).item) {
							break
						}
					}
					req(reqList, reqInfo)
				}
			case actDeselectAll:
				if t.multi > 0 {
					for i := 0; i < t.merger.Length() && len(t.selected) > 0; i++ {
						t.deselectItem(t.merger.Get(i).item)
					}
					req(reqList, reqInfo)
				}
			case actClose:
				if t.hasPreviewWindow() {
					t.activePreviewOpts.Toggle()
					updatePreviewWindow(false)
				} else {
					req(reqQuit)
				}
			case actSelect:
				current := t.currentItem()
				if t.multi > 0 && current != nil && t.selectItemChanged(current) {
					req(reqList, reqInfo)
				}
			case actDeselect:
				current := t.currentItem()
				if t.multi > 0 && current != nil && t.deselectItemChanged(current) {
					req(reqList, reqInfo)
				}
			case actToggle:
				if t.multi > 0 && t.merger.Length() > 0 && toggle() {
					req(reqList)
				}
			case actToggleAll:
				if t.multi > 0 {
					prevIndexes := make(map[int]struct{})
					for i := 0; i < t.merger.Length() && len(t.selected) > 0; i++ {
						item := t.merger.Get(i).item
						if _, found := t.selected[item.Index()]; found {
							prevIndexes[i] = struct{}{}
							t.deselectItem(item)
						}
					}

					for i := 0; i < t.merger.Length(); i++ {
						if _, found := prevIndexes[i]; !found {
							item := t.merger.Get(i).item
							if !t.selectItem(item) {
								break
							}
						}
					}
					req(reqList, reqInfo)
				}
			case actToggleIn:
				if t.layout != layoutDefault {
					return doAction(&action{t: actToggleUp})
				}
				return doAction(&action{t: actToggleDown})
			case actToggleOut:
				if t.layout != layoutDefault {
					return doAction(&action{t: actToggleDown})
				}
				return doAction(&action{t: actToggleUp})
			case actToggleDown:
				if t.multi > 0 && t.merger.Length() > 0 && toggle() {
					t.vmove(-1, true)
					req(reqList)
				}
			case actToggleUp:
				if t.multi > 0 && t.merger.Length() > 0 && toggle() {
					t.vmove(1, true)
					req(reqList)
				}
			case actDown:
				t.vmove(-1, true)
				req(reqList)
			case actUp:
				t.vmove(1, true)
				req(reqList)
			case actAccept:
				req(reqClose)
			case actAcceptNonEmpty:
				if len(t.selected) > 0 || t.merger.Length() > 0 || !t.reading && t.count == 0 {
					req(reqClose)
				}
			case actAcceptOrPrintQuery:
				if len(t.selected) > 0 || t.merger.Length() > 0 {
					req(reqClose)
				} else {
					req(reqPrintQuery)
				}
			case actClearScreen:
				req(reqFullRedraw)
			case actClearQuery:
				t.input = []rune{}
				t.cx = 0
			case actClearSelection:
				if t.multi > 0 {
					t.selected = make(map[int32]selectedItem)
					t.version++
					req(reqList, reqInfo)
				}
			case actFirst:
				t.vset(0)
				req(reqList)
			case actLast:
				t.vset(t.merger.Length() - 1)
				req(reqList)
			case actPosition:
				if n, e := strconv.Atoi(a.a); e == nil {
					if n > 0 {
						n--
					} else if n < 0 {
						n += t.merger.Length()
					}
					t.vset(n)
					req(reqList)
				}
			case actPut:
				str := []rune(a.a)
				suffix := copySlice(t.input[t.cx:])
				t.input = append(append(t.input[:t.cx], str...), suffix...)
				t.cx += len(str)
			case actPrint:
				t.printQueue = append(t.printQueue, a.a)
			case actUnixLineDiscard:
				beof = len(t.input) == 0
				if t.cx > 0 {
					t.yanked = copySlice(t.input[:t.cx])
					t.input = t.input[t.cx:]
					t.cx = 0
				}
			case actUnixWordRubout:
				beof = len(t.input) == 0
				if t.cx > 0 {
					t.rubout("\\s\\S")
				}
			case actBackwardKillWord:
				beof = len(t.input) == 0
				if t.cx > 0 {
					t.rubout(t.wordRubout)
				}
			case actYank:
				suffix := copySlice(t.input[t.cx:])
				t.input = append(append(t.input[:t.cx], t.yanked...), suffix...)
				t.cx += len(t.yanked)
			case actPageUp:
				t.vmove(t.maxItems()-1, false)
				req(reqList)
			case actPageDown:
				t.vmove(-(t.maxItems() - 1), false)
				req(reqList)
			case actHalfPageUp:
				t.vmove(t.maxItems()/2, false)
				req(reqList)
			case actHalfPageDown:
				t.vmove(-(t.maxItems() / 2), false)
				req(reqList)
			case actOffsetUp, actOffsetDown:
				diff := 1
				if a.t == actOffsetDown {
					diff = -1
				}
				if t.layout == layoutReverse {
					diff *= -1
				}
				t.offset += diff
				before := t.offset
				t.constrain()
				if before != t.offset {
					t.offset = before
					if t.layout == layoutReverse {
						diff *= -1
					}
					t.vmove(diff, false)
				}
				req(reqList)
			case actOffsetMiddle:
				soff := t.scrollOff
				t.scrollOff = t.window.Height()
				t.constrain()
				t.scrollOff = soff
			case actJump:
				t.jumping = jumpEnabled
				req(reqJump)
			case actJumpAccept:
				t.jumping = jumpAcceptEnabled
				req(reqJump)
			case actBackwardWord:
				t.cx = findLastMatch(t.wordRubout, string(t.input[:t.cx])) + 1
			case actForwardWord:
				t.cx += findFirstMatch(t.wordNext, string(t.input[t.cx:])) + 1
			case actKillWord:
				ncx := t.cx +
					findFirstMatch(t.wordNext, string(t.input[t.cx:])) + 1
				if ncx > t.cx {
					t.yanked = copySlice(t.input[t.cx:ncx])
					t.input = append(t.input[:t.cx], t.input[ncx:]...)
				}
			case actKillLine:
				if t.cx < len(t.input) {
					t.yanked = copySlice(t.input[t.cx:])
					t.input = t.input[:t.cx]
				}
			case actChar:
				prefix := copySlice(t.input[:t.cx])
				t.input = append(append(prefix, event.Char), t.input[t.cx:]...)
				t.cx++
			case actPrevHistory:
				if t.history != nil {
					t.history.override(string(t.input))
					t.input = trimQuery(t.history.previous())
					t.cx = len(t.input)
				}
			case actNextHistory:
				if t.history != nil {
					t.history.override(string(t.input))
					t.input = trimQuery(t.history.next())
					t.cx = len(t.input)
				}
			case actToggleSearch:
				t.paused = !t.paused
				changed = !t.paused
				req(reqPrompt)
			case actToggleTrack:
				switch t.track {
				case trackEnabled:
					t.track = trackDisabled
				case trackDisabled:
					t.track = trackEnabled
				}
				req(reqInfo)
			case actToggleTrackCurrent:
				switch t.track {
				case trackCurrent:
					t.track = trackDisabled
				case trackDisabled:
					t.track = trackCurrent
				}
				req(reqInfo)
			case actShowHeader:
				t.headerVisible = true
				req(reqList, reqInfo, reqPrompt, reqHeader)
			case actHideHeader:
				t.headerVisible = false
				req(reqList, reqInfo, reqPrompt, reqHeader)
			case actToggleHeader:
				t.headerVisible = !t.headerVisible
				req(reqList, reqInfo, reqPrompt, reqHeader)
			case actTrackCurrent:
				if t.track == trackDisabled {
					t.track = trackCurrent
				}
				req(reqInfo)
			case actUntrackCurrent:
				if t.track == trackCurrent {
					t.track = trackDisabled
				}
				req(reqInfo)
			case actEnableSearch:
				t.paused = false
				changed = true
				req(reqPrompt)
			case actDisableSearch:
				t.paused = true
				req(reqPrompt)
			case actSigStop:
				p, err := os.FindProcess(os.Getpid())
				if err == nil {
					t.sigstop = true
					t.tui.Clear()
					t.tui.Pause(t.fullscreen)
					notifyStop(p)
					t.mutex.Unlock()
					return false
				}
			case actMouse:
				me := event.MouseEvent
				mx, my := me.X, me.Y
				clicked := !wasDown && me.Down
				wasDown = me.Down
				if !me.Down {
					barDragging = false
					pbarDragging = false
					previewDraggingPos = -1
				}

				// Scrolling
				if me.S != 0 {
					if t.window.Enclose(my, mx) && t.merger.Length() > 0 {
						evt := tui.ScrollUp
						if me.Mod {
							evt = tui.SScrollUp
						}
						if me.S < 0 {
							evt = tui.ScrollDown
							if me.Mod {
								evt = tui.SScrollDown
							}
						}
						return doActions(actionsFor(evt))
					} else if t.hasPreviewWindow() && t.pwindow.Enclose(my, mx) {
						evt := tui.PreviewScrollUp
						if me.S < 0 {
							evt = tui.PreviewScrollDown
						}
						return doActions(actionsFor(evt))
					}
					break
				}

				// Preview dragging
				if me.Down && (previewDraggingPos >= 0 || clicked && t.hasPreviewWindow() && t.pwindow.Enclose(my, mx)) {
					if previewDraggingPos > 0 {
						scrollPreviewBy(previewDraggingPos - my)
					}
					previewDraggingPos = my
					break
				}

				// Preview scrollbar dragging
				headerLines := t.previewOpts.headerLines
				pbarDragging = me.Down && (pbarDragging || clicked && t.hasPreviewWindow() && my >= t.pwindow.Top()+headerLines && my < t.pwindow.Top()+t.pwindow.Height() && mx == t.pwindow.Left()+t.pwindow.Width())
				if pbarDragging {
					effectiveHeight := t.pwindow.Height() - headerLines
					numLines := len(t.previewer.lines) - headerLines
					barLength, _ := getScrollbar(1, numLines, effectiveHeight, util.Min(numLines-effectiveHeight, t.previewer.offset-headerLines))
					if barLength > 0 {
						y := my - t.pwindow.Top() - headerLines - barLength/2
						y = util.Constrain(y, 0, effectiveHeight-barLength)
						// offset = (total - maxItems) * barStart / (maxItems - barLength)
						t.previewer.offset = headerLines + int(math.Ceil(float64(y)*float64(numLines-effectiveHeight)/float64(effectiveHeight-barLength)))
						t.previewer.following.Set(t.previewer.offset >= numLines-effectiveHeight)
						req(reqPreviewRefresh)
					}
					break
				}

				// Ignored
				if !t.window.Enclose(my, mx) && !barDragging {
					break
				}

				// Translate coordinates
				mx -= t.window.Left()
				my -= t.window.Top()
				min := 2 + t.visibleHeaderLines()
				if t.noSeparatorLine() {
					min--
				}
				h := t.window.Height()
				switch t.layout {
				case layoutDefault:
					my = h - my - 1
				case layoutReverseList:
					if my < h-min {
						my += min
					} else {
						my = h - my - 1
					}
				}

				// Scrollbar dragging
				barDragging = me.Down && (barDragging || clicked && my >= min && mx == t.window.Width()-1)
				if barDragging {
					barLength, barStart := t.getScrollbar()
					if barLength > 0 {
						maxItems := t.maxItems()
						if newBarStart := util.Constrain(my-min-barLength/2, 0, maxItems-barLength); newBarStart != barStart {
							total := t.merger.Length()
							prevOffset := t.offset
							// barStart = (maxItems - barLength) * t.offset / (total - maxItems)
							perLine := t.avgNumLines()
							t.offset = int(math.Ceil(float64(newBarStart) * float64(total*perLine-maxItems) / float64(maxItems*perLine-barLength)))
							t.cy = t.offset + t.cy - prevOffset
							req(reqList)
						}
					}
					break
				}

				// There can be empty lines after the list in multi-line mode
				prevLine := t.prevLines[my]
				if prevLine.empty {
					break
				}

				// Double-click on an item
				cy := prevLine.cy
				if me.Double && mx < t.window.Width()-1 {
					// Double-click
					if my >= min {
						if t.vset(cy) && t.cy < t.merger.Length() {
							return doActions(actionsFor(tui.DoubleClick))
						}
					}
					break
				}

				if me.Down {
					mxCons := util.Constrain(mx-t.promptLen, 0, len(t.input))
					if my == t.promptLine() && mxCons >= 0 {
						// Prompt
						t.cx = mxCons + t.xoffset
					} else if my >= min {
						t.vset(cy)
						req(reqList)
						evt := tui.RightClick
						if me.Mod {
							evt = tui.SRightClick
						}
						if me.Left {
							evt = tui.LeftClick
							if me.Mod {
								evt = tui.SLeftClick
							}
						}
						return doActions(actionsFor(evt))
					} else if t.headerVisible {
						// Header
						numLines := t.visibleHeaderLines()
						lineOffset := 0
						if !t.headerFirst {
							// offset for info line
							if t.noSeparatorLine() {
								lineOffset = 1
							} else {
								lineOffset = 2
							}
						}
						my -= lineOffset
						mx -= 2 // offset gutter
						if my >= 0 && my < numLines && mx >= 0 {
							if t.layout == layoutReverse {
								t.clickHeaderLine = my + 1
							} else {
								t.clickHeaderLine = numLines - my
							}
							t.clickHeaderColumn = mx + 1
							return doActions(actionsFor(tui.ClickHeader))
						}
					}
				}
			case actReload, actReloadSync:
				t.failed = nil

				valid, list := t.buildPlusList(a.a, false)
				if !valid {
					// We run the command even when there's no match
					// 1. If the template doesn't have any slots
					// 2. If the template has {q}
					slot, _, forceUpdate := hasPreviewFlags(a.a)
					valid = !slot || forceUpdate
				}
				if valid {
					command, tempFiles := t.replacePlaceholder(a.a, false, string(t.input), list)
					newCommand = &commandSpec{command, tempFiles}
					reloadSync = a.t == actReloadSync
					t.reading = true
				}
			case actUnbind:
				if keys, err := parseKeyChords(a.a, "PANIC"); err == nil {
					for key := range keys {
						delete(t.keymap, key)
					}
				}
			case actRebind:
				if keys, err := parseKeyChords(a.a, "PANIC"); err == nil {
					for key := range keys {
						if originalAction, found := t.keymapOrg[key]; found {
							t.keymap[key] = originalAction
						}
					}
				}
			case actChangePreview:
				if t.previewOpts.command != a.a {
					t.previewOpts.command = a.a
					updatePreviewWindow(false)
					refreshPreview(t.previewOpts.command)
				}
			case actChangePreviewWindow:
				currentPreviewOpts := t.previewOpts

				// Reset preview options and apply the additional options
				t.previewOpts = t.initialPreviewOpts
				t.previewOpts.command = currentPreviewOpts.command

				// Split window options
				tokens := strings.Split(a.a, "|")
				if len(tokens[0]) > 0 && t.initialPreviewOpts.hidden {
					t.previewOpts.hidden = false
				}
				parsePreviewWindow(&t.previewOpts, tokens[0])
				if len(tokens) > 1 {
					a.a = strings.Join(append(tokens[1:], tokens[0]), "|")
				}

				// Full redraw
				if !currentPreviewOpts.sameLayout(t.previewOpts) {
					// Preview command can be running in the background if the size of
					// the preview window is 0 but not 'hidden'
					wasHidden := currentPreviewOpts.hidden
					updatePreviewWindow(false)
					if wasHidden && t.hasPreviewWindow() {
						// Restart
						refreshPreview(t.previewOpts.command)
					} else if t.previewOpts.hidden {
						// Cancel
						t.cancelPreview()
					} else {
						// Refresh
						req(reqPreviewRefresh)
					}
				} else if !currentPreviewOpts.sameContentLayout(t.previewOpts) {
					t.previewed.version = 0
					req(reqPreviewRefresh)
				}

				// Adjust scroll offset
				if t.hasPreviewWindow() && currentPreviewOpts.scroll != t.previewOpts.scroll {
					scrollPreviewTo(t.evaluateScrollOffset())
				}

				// Resume following
				t.previewer.following.Force(t.previewOpts.follow)
			case actNextSelected, actPrevSelected:
				if len(t.selected) > 0 {
					total := t.merger.Length()
					for i := 1; i < total; i++ {
						y := (t.cy + i) % total
						if t.layout == layoutDefault && a.t == actNextSelected ||
							t.layout != layoutDefault && a.t == actPrevSelected {
							y = (t.cy - i + total) % total
						}
						if _, found := t.selected[t.merger.Get(y).item.Index()]; found {
							t.vset(y)
							req(reqList)
							break
						}
					}
				}
			}

			if !processExecution(a.t) {
				t.lastAction = a.t
			}
			return true
		}

		if t.jumping == jumpDisabled || len(actions) > 0 {
			// Break out of jump mode if any action is submitted to the server
			if t.jumping != jumpDisabled {
				t.jumping = jumpDisabled
				if acts, prs := t.keymap[tui.JumpCancel.AsEvent()]; prs && !doActions(acts) {
					continue
				}
				req(reqList)
			}
			if len(actions) == 0 {
				actions = t.keymap[event.Comparable()]
			}
			if len(actions) == 0 && event.Type == tui.Rune {
				doAction(&action{t: actChar})
			} else if !doActions(actions) {
				continue
			}
			t.truncateQuery()
			queryChanged = string(previousInput) != string(t.input)
			changed = changed || queryChanged
			if onChanges, prs := t.keymap[tui.Change.AsEvent()]; queryChanged && prs && !doActions(onChanges) {
				continue
			}
			if onEOFs, prs := t.keymap[tui.BackwardEOF.AsEvent()]; beof && prs && !doActions(onEOFs) {
				continue
			}
		} else {
			jumpEvent := tui.JumpCancel
			if event.Type == tui.Rune {
				if idx := strings.IndexRune(t.jumpLabels, event.Char); idx >= 0 && idx < t.maxItems() && idx < t.merger.Length() {
					jumpEvent = tui.Jump
					t.cy = idx + t.offset
					if t.jumping == jumpAcceptEnabled {
						req(reqClose)
					}
				}
			}
			t.jumping = jumpDisabled
			if acts, prs := t.keymap[jumpEvent.AsEvent()]; prs && !doActions(acts) {
				continue
			}
			req(reqList)
		}

		if queryChanged && t.canPreview() && len(t.previewOpts.command) > 0 {
			_, _, forceUpdate := hasPreviewFlags(t.previewOpts.command)
			if forceUpdate {
				t.version++
			}
		}

		if queryChanged || t.cx != previousCx {
			req(reqPrompt)
		}

		reload := changed || newCommand != nil
		var reloadRequest *searchRequest
		if reload {
			reloadRequest = &searchRequest{sort: t.sort, sync: reloadSync, command: newCommand, environ: t.environ(), changed: changed}
		}
		t.mutex.Unlock() // Must be unlocked before touching reqBox

		if reload {
			t.eventBox.Set(EvtSearchNew, *reloadRequest)
		}
		for _, event := range events {
			t.reqBox.Set(event, nil)
		}
	}
	return nil
}

func (t *Terminal) constrain() {
	// count of items to display allowed by filtering
	count := t.merger.Length()
	maxLines := t.maxItems()

	// May need to try again after adjusting the offset
	t.offset = util.Constrain(t.offset, 0, count)
	for tries := 0; tries < maxLines; tries++ {
		numItems := maxLines
		// How many items can be fit on screen including the current item?
		if t.multiLine && t.merger.Length() > 0 {
			numItemsFound := 0
			linesSum := 0

			add := func(i int) bool {
				lines, _ := t.merger.Get(i).item.text.NumLines(numItems - linesSum)
				linesSum += lines
				if linesSum >= numItems {
					if numItemsFound == 0 {
						numItemsFound = 1
					}
					return false
				}
				numItemsFound++
				return true
			}

			for i := t.offset; i < t.merger.Length(); i++ {
				if !add(i) {
					break
				}
			}

			// We can possibly fit more items "before" the offset on screen
			if linesSum < numItems {
				for i := t.offset - 1; i >= 0; i-- {
					if !add(i) {
						break
					}
				}
			}

			numItems = numItemsFound
		}

		t.cy = util.Constrain(t.cy, 0, util.Max(0, count-1))
		minOffset := util.Max(t.cy-numItems+1, 0)
		maxOffset := util.Max(util.Min(count-numItems, t.cy), 0)
		prevOffset := t.offset
		t.offset = util.Constrain(t.offset, minOffset, maxOffset)
		if t.scrollOff > 0 {
			scrollOff := util.Min(maxLines/2, t.scrollOff)
			newOffset := t.offset
			// 2-phase adjustment to avoid infinite loop of alternating between moving up and down
			for phase := 0; phase < 2; phase++ {
				for {
					prevOffset := newOffset
					numItems := t.merger.Length()
					itemLines := 1
					if t.multiLine && t.cy < numItems {
						itemLines, _ = t.merger.Get(t.cy).item.text.NumLines(maxLines)
					}
					linesBefore := t.cy - newOffset
					if t.multiLine {
						linesBefore = 0
						for i := newOffset; i < t.cy && i < numItems; i++ {
							lines, _ := t.merger.Get(i).item.text.NumLines(maxLines - linesBefore - itemLines)
							linesBefore += lines
						}
					}
					linesAfter := maxLines - (linesBefore + itemLines)

					// Stuck in the middle, nothing to do
					if linesBefore < scrollOff && linesAfter < scrollOff {
						break
					}

					if phase == 0 && linesBefore < scrollOff {
						newOffset = util.Max(minOffset, newOffset-1)
					} else if phase == 1 && linesAfter < scrollOff {
						newOffset = util.Min(maxOffset, newOffset+1)
					}
					if newOffset == prevOffset {
						break
					}
				}
				t.offset = newOffset
			}
		}
		if t.offset == prevOffset {
			break
		}
	}
}

func (t *Terminal) vmove(o int, allowCycle bool) {
	if t.layout != layoutDefault {
		o *= -1
	}
	dest := t.cy + o
	if t.cycle && allowCycle {
		max := t.merger.Length() - 1
		if dest > max {
			if t.cy == max {
				dest = 0
			}
		} else if dest < 0 {
			if t.cy == 0 {
				dest = max
			}
		}
	}
	t.vset(dest)
}

func (t *Terminal) vset(o int) bool {
	t.cy = util.Constrain(o, 0, t.merger.Length()-1)
	return t.cy == o
}

func (t *Terminal) maxItems() int {
	max := t.window.Height() - 2 - t.visibleHeaderLines()
	if t.noSeparatorLine() {
		max++
	}
	return util.Max(max, 0)
}

func (t *Terminal) dumpItem(i *Item) StatusItem {
	if i == nil {
		return StatusItem{}
	}
	return StatusItem{
		Index: int(i.Index()),
		Text:  i.AsString(t.ansi),
	}
}

func (t *Terminal) tryLock(timeout time.Duration) bool {
	sleepDuration := 10 * time.Millisecond

	for {
		if t.mutex.TryLock() {
			return true
		}

		timeout -= sleepDuration
		if timeout <= 0 {
			break
		}
		time.Sleep(sleepDuration)
	}
	return false
}

func (t *Terminal) dumpStatus(params getParams) string {
	if !t.tryLock(channelTimeout) {
		return ""
	}
	defer t.mutex.Unlock()

	selectedItems := t.sortSelected()
	selected := make([]StatusItem, util.Max(0, util.Min(params.limit, len(selectedItems)-params.offset)))
	for i := range selected {
		selected[i] = t.dumpItem(selectedItems[i+params.offset].item)
	}

	matches := make([]StatusItem, util.Max(0, util.Min(params.limit, t.merger.Length()-params.offset)))
	for i := range matches {
		matches[i] = t.dumpItem(t.merger.Get(i + params.offset).item)
	}

	var current *StatusItem
	currentItem := t.currentItem()
	if currentItem != nil {
		item := t.dumpItem(currentItem)
		current = &item
	}

	dump := Status{
		Reading:    t.reading,
		Progress:   t.progress,
		Query:      string(t.input),
		Position:   t.cy,
		Sort:       t.sort,
		TotalCount: t.count,
		MatchCount: t.merger.Length(),
		Current:    current,
		Matches:    matches,
		Selected:   selected,
	}
	bytes, _ := json.Marshal(&dump) // TODO: Errors?
	return string(bytes)
}
