ditty/main.go

package main

import (
	"flag"
	"fmt"
	"log"
	"net/http"
	_ "net/http/pprof"
	"os"
	"os/signal"
	"path/filepath"
	"runtime/pprof"
	"strings"
	"syscall"
	"time"

	"code.rocketnine.space/tslocum/ez"
)

const (
	volumeBase = 2

	versionInfo = `ditty - Audio player - v0.0.0
https://code.rocketnine.space/tslocum/ditty
The MIT License (MIT)
Copyright (c) 2020 Trevor Slocum <trevor@rocketnine.space>
`
)

var (
	configPath         string
	printVersionInfo   bool
	bufferSize         time.Duration
	debugAddress       string
	cpuProfile         string
	streamFdInt        int
	streamFd           *os.File
	restrictLibrary    string
	showHiddenFolders  bool
	startingVolumeFlag int
	disableAutoplay    bool
	disableMouse       bool

	version = "0.0.0"
	done    = make(chan bool)
)

func exit() {
	done <- true
}

func main() {
	log.SetFlags(0)

	flag.StringVar(&configPath, "config", "", "path to configuration file")
	flag.BoolVar(&printVersionInfo, "version", false, "print version information and exit")
	flag.StringVar(&config.Layout, "layout", defaultLayout, "layout of interface elements")
	flag.IntVar(&streamFdInt, "fd", -1, "stream audio to file descriptor")
	flag.IntVar(&startingVolumeFlag, "volume", -1, "initial volume level 0-100")
	flag.StringVar(&restrictLibrary, "restrict-library", "", "restrict library to path")
	flag.BoolVar(&disableAutoplay, "disable-autoplay", false, "disable automatically playing the queue")
	flag.BoolVar(&disableMouse, "disable-mouse", false, "disable mouse support")
	flag.DurationVar(&bufferSize, "buffer-size", defaultBufferSize, "audio buffer size")
	flag.StringVar(&debugAddress, "debug-address", "", "address to serve debug info")
	flag.BoolVar(&showHiddenFolders, "hidden-folders", false, "show hidden folders")
	flag.StringVar(&cpuProfile, "cpu-profile", "", "path to save CPU profiling")
	flag.Parse()

	if printVersionInfo {
		fmt.Print(strings.Replace(versionInfo, "0.0.0", version, 1))
		return
	}

	if restrictLibrary != "" {
		var err error
		restrictLibrary, err = filepath.Abs(restrictLibrary)
		if err != nil {
			panic(fmt.Sprintf("failed to restrict library to %s: %s", restrictLibrary, err))
		}
	}

	if debugAddress != "" {
		go func() {
			panic(http.ListenAndServe(debugAddress, nil))
		}()
	}

	if cpuProfile != "" {
		f, err := os.Create(cpuProfile)
		if err != nil {
			panic(fmt.Sprintf("could not create CPU profile: %s", err))
		}
		defer f.Close()

		if err := pprof.StartCPUProfile(f); err != nil {
			panic(fmt.Sprintf("could not start CPU profile: %s", err))
		}
		defer pprof.StopCPUProfile()
	}

	if configPath == "" {
		var err error
		configPath, err = ez.DefaultConfigPath("ditty")
		if err != nil {
			panic(fmt.Sprintf("failed to determine default configuration file path: %s", err))
		}
	}

	err := ez.Deserialize(config, configPath)
	if err != nil {
		panic(fmt.Sprintf("failed to read configuration file: %s", err))
	}

	if startingVolumeFlag >= 0 {
		config.Volume = startingVolumeFlag
	}

	err = setKeyBinds()
	if err != nil {
		panic(fmt.Sprintf("failed to set keybinds: %s", err))
	}

	err = initTUI()
	if err != nil {
		panic(fmt.Sprintf("failed to initialize terminal user interface: %s", err))
	}
	defer app.HandlePanic()

	sigc := make(chan os.Signal, 1)
	signal.Notify(sigc,
		syscall.SIGINT,
		syscall.SIGTERM)
	go func() {
		<-sigc

		done <- true
	}()

	go func() {
		err := app.Run()
		if err != nil {
			panic(err)
		}

		done <- true
	}()

	var vol float64
	if config.Volume == 0 {
		vol = -7.5
	} else {
		vol = -7.5 + float64(7.5)*(float64(config.Volume)/float64(100))
		if vol < -7.0 {
			vol = -7.0
		}
	}
	setVolume(roundUnit(vol, 0.5))

	startPath := strings.Join(flag.Args(), " ")
	if startPath == "" {
		if restrictLibrary != "" {
			startPath = restrictLibrary
		} else if config.Remember && config.Dir != "" {
			startPath = config.Dir
		} else {
			wd, err := os.Getwd()
			if err != nil || wd == "" {
				homeDir, err := os.UserHomeDir()
				if err == nil && homeDir != "" {
					startPath = homeDir
				}
			} else {
				startPath = wd
			}
		}
	}
	if startPath == "" {
		panic("supply a path to browse")
	}
	fileInfo, err := os.Stat(startPath)
	if err != nil {
		panic(err)
	}

	var playing bool
	if fileInfo.IsDir() {
		browseFolder(startPath)
	} else {
		browseFolder(filepath.Dir(startPath))

		audioFile, err := openFile(strings.Join(flag.Args(), " "), nil)
		if err != nil {
			statusText = err.Error()
			app.QueueUpdateDraw(updateMain)
		} else {
			play(audioFile)
			playing = true
		}
	}

	if config.Remember && config.QueueFiles != nil {
		queueFiles = config.QueueFiles
		app.QueueUpdateDraw(func() {
			updateQueue()
			queueList.SetCurrentItem(config.QueuePlaying)
			if len(queueFiles) > 0 && !playing {
				pauseNext = true
				seekNext = config.AudioPosition
				go queueSelect(config.QueuePlaying)
			}
		})
	}

	if config.Remember {
		go func() {
			t := time.NewTicker(5 * time.Minute)
			for range t.C {
				saveAppState()
				ez.Serialize(config, configPath) // Failing isn't an issue, this could be logged though
			}
		}()
	}

	defer func() {
		if app != nil {
			app.Stop()
		}
	}()

	t := time.NewTicker(time.Second)
	for {
		select {
		case <-done:
			if config.Remember {
				saveAppState()
			} else {
				clearAppState()
			}
			ez.Serialize(config, configPath) // Failing isn't an issue, this could be logged though

			if streamFd != nil {
				streamFd.Close()
			}

			return
		case <-t.C:
			updateStatus()
		}
	}
}