ditty/gui.go

package main

import (
	"fmt"
	"math"
	"os"
	"path"
	"path/filepath"
	"strings"
	"time"

	"github.com/mattn/go-runewidth"

	"github.com/gdamore/tcell"

	"github.com/faiface/beep"

	"git.sr.ht/~tslocum/cview"
	"github.com/faiface/beep/speaker"
)

var (
	app             *cview.Application
	mainbuf         *cview.TextView
	queuebuf        *cview.TextView
	topstatusbuf    *cview.TextView
	bottomstatusbuf *cview.TextView

	mainBufferFiles     []*LibraryEntry
	mainBufferCursor    int
	mainBufferDirectory string
	mainBufferOrigin    int

	seekStart, seekEnd     int
	volumeStart, volumeEnd int

	screenWidth, screenHeight int
	mainBufHeight             int

	statusText string
)

func initTUI() error {
	app = cview.NewApplication()

	app.EnableMouse()

	app.SetInputCapture(handleKeyPress)

	app.SetAfterResizeFunc(handleResize)

	app.SetMouseCapture(handleMouse)

	grid := cview.NewGrid().SetRows(-2, -1, 1, 1).SetColumns(-1)

	mainbuf = cview.NewTextView().SetDynamicColors(true).SetWrap(true).SetWordWrap(false)
	queuebuf = cview.NewTextView().SetDynamicColors(true).SetWrap(true).SetWordWrap(false)
	topstatusbuf = cview.NewTextView().SetWrap(false).SetWordWrap(false)
	bottomstatusbuf = cview.NewTextView().SetWrap(false).SetWordWrap(false)

	mainbuf.SetBorder(true).SetTitleAlign(cview.AlignLeft)

	queuebuf.SetBorder(true).SetTitleAlign(cview.AlignLeft).SetTitle(" Queue ")

	grid.AddItem(mainbuf, 0, 0, 1, 1, 0, 0, false)
	grid.AddItem(queuebuf, 1, 0, 1, 1, 0, 0, false)
	grid.AddItem(topstatusbuf, 2, 0, 1, 1, 0, 0, false)
	grid.AddItem(bottomstatusbuf, 3, 0, 1, 1, 0, 0, false)

	mainbuf.SetDrawFunc(func(screen tcell.Screen, x, y, width, height int) (i int, i2 int, i3 int, i4 int) {
		mainBufHeight = height
		return mainbuf.GetInnerRect()
	})

	app.SetRoot(grid, true)

	return nil
}

func browseFolder(browse string) {
	var err error
	browse, err = filepath.Abs(browse)
	if err != nil {
		return
	}

	mainBufferFiles = scanFolder(browse)

	if len(mainBufferFiles) > 0 {
		mainBufferCursor = 1
	} else {
		mainBufferCursor = 0
	}

	mainBufferDirectory = browse
	app.QueueUpdateDraw(updateMain)
}

func updateMain() {
	var titleText string
	if statusText != "" {
		titleText = statusText
	} else {
		titleText = mainBufferDirectory

		truncated := false
		widthRequirement := 4
		for {
			if runewidth.StringWidth(titleText) <= screenWidth-widthRequirement || !strings.ContainsRune(titleText, os.PathSeparator) {
				break
			}

			titleText = titleText[strings.IndexRune(titleText, '/')+1:]

			truncated = true
			widthRequirement = 8
		}
		if truncated {
			titleText = ".../" + titleText
		}
		titleText = runewidth.Truncate(titleText, screenWidth-4, "...")
	}
	mainbuf.SetTitle(" " + titleText + " ")

	var printed int

	var newBufferText string
	if mainBufferOrigin == 0 {
		if mainBufferCursor == 0 {
			newBufferText += "[::r]"
		}
		var line string
		if mainBufferDirectory == "/" {
			line = "./"
		} else {
			line = "../"
		}
		newBufferText += line
		for i := len(line); i < screenWidth-2; i++ {
			newBufferText += " "
		}
		if mainBufferCursor == 0 {
			newBufferText += "[-]"
		}
		printed++
	}
	for i, entry := range mainBufferFiles {
		if i < mainBufferOrigin-1 || i-mainBufferOrigin-1 > mainBufHeight-1 {
			continue
		}

		if printed > 0 {
			newBufferText += "\n"
		}

		if i == mainBufferCursor-1 {
			newBufferText += "[::r]"
		}
		var line string
		if entry.File.IsDir() {
			line = entry.File.Name() + "/"
		} else {
			line = entry.String()
		}
		newBufferText += line
		for i := runewidth.StringWidth(line); i < screenWidth-2; i++ {
			newBufferText += " "
		}
		if i == mainBufferCursor-1 {
			newBufferText += "[-]"
		}

		printed++
		if printed == mainBufHeight-2 {
			break
		}
	}

	mainbuf.SetText(newBufferText)
}

func updateQueue() {
	// TODO
}

func updateStatus() {
	var sampleRate beep.SampleRate
	var d time.Duration
	var l time.Duration
	var v float64
	var topStatusExtra string

	speaker.Lock()
	if playingStreamer == nil {
		topstatusbuf.SetText("")
		bottomstatusbuf.SetText("")
		speaker.Unlock()
		return
	}

	sampleRate = playingFormat.SampleRate
	d = playingFormat.SampleRate.D(playingStreamer.Position()).Truncate(time.Second)
	l = playingFormat.SampleRate.D(playingStreamer.Len()).Truncate(time.Second)
	v = volume.Volume
	paused := ctrl.Paused
	topStatusExtra = fmt.Sprintf("%dHz %s", sampleRate.N(time.Second), fileFormat(playingFileName))
	if paused {
		topStatusExtra = "Paused  " + topStatusExtra
	}

	speaker.Unlock()

	topStatus := " "
	if playingFileInfo != "" {
		topStatus += playingFileInfo
	} else {
		topStatus += playingFileName
	}
	topStatusMaxFileLength := screenWidth - len(topStatusExtra) - 1
	if topStatusMaxFileLength >= 7 {
		if len(topStatus) > topStatusMaxFileLength {
			topStatus = topStatus[:topStatusMaxFileLength]
		}

		padding := screenWidth - runewidth.StringWidth(topStatus) - len(topStatusExtra) - 1
		for i := 0; i < padding; i++ {
			topStatus += " "
		}

		topStatus += topStatusExtra
	}
	topstatusbuf.SetText(topStatus)

	var vol string
	if volume.Silent {
		vol = "Mut "

		for i := -7.5; i < 0.0; i += 0.5 {
			vol += string(tcell.RuneHLine)
		}
	} else {
		vol = "Vol "

		for i := -7.5; i < v-0.5; i += 0.5 {
			vol += string(tcell.RuneHLine)
		}
		vol += string(tcell.RuneBlock)
		for i := v; i < 0; i += 0.5 {
			vol += string(tcell.RuneHLine)
		}
	}

	bottomStatus := fmt.Sprintf("%s  %s", formatDuration(l), vol)

	var durationIndicator string
	if paused {
		durationIndicator = "||"
	} else {
		durationIndicator = string(tcell.RuneBlock)
	}

	padding := screenWidth - runewidth.StringWidth(bottomStatus) - len(formatDuration(d)) - runewidth.StringWidth(durationIndicator) - 3
	position := int(float64(padding) * (float64(d) / float64(l)))
	if position > padding-1 {
		position = padding - 1
	}
	if paused && position > 0 {
		position--
	}

	var durationBar string
	for i := 0; i < padding; i++ {
		if i == position {
			durationBar += durationIndicator
		} else {
			durationBar += string(tcell.RuneHLine)
		}
	}

	seekStart = len(formatDuration(d)) + 2
	seekEnd = seekStart + padding - 1

	volumeStart = seekEnd + len(formatDuration(l)) + 4
	volumeEnd = screenWidth - 2

	bottomstatusbuf.SetText(" " + formatDuration(d) + " " + durationBar + " " + bottomStatus)
}

func formatDuration(d time.Duration) string {
	minutes := int(math.Floor(float64(d) / float64(time.Minute)))
	seconds := int((d % time.Minute) / time.Second)

	return fmt.Sprintf("%02d:%02d", minutes, seconds)
}

func handleResize(screen tcell.Screen) {
	screenWidth, screenHeight = screen.Size()

	updateMain()
	updateQueue()
	updateStatus()
}

func selectTrack() {
	if mainBufferCursor == 0 {
		browseFolder(path.Join(mainBufferDirectory, ".."))
		return
	}
	nextStreamer = nil
	nextFormat = beep.Format{}

	entry := selectedEntry()
	if entry.File.IsDir() {
		browseFolder(path.Join(mainBufferDirectory, path.Base(entry.File.Name())))
		return
	}

	audioFile, err := openFile(path.Join(mainBufferDirectory, entry.File.Name()))
	if err != nil {
		statusText = err.Error()
		go func() {
			time.Sleep(5 * time.Second)
			statusText = ""
			app.QueueUpdateDraw(updateMain)
		}()
		app.QueueUpdateDraw(updateMain)
		return
	}
	go play(audioFile)

	app.QueueUpdateDraw(updateStatus)
}