package main

import (
	"errors"
	"fmt"
	"io"
	"net/http"
	"os"
	"os/exec"
	"runtime"
	"strings"
	"time"

	disabledicon "gitea.ronald1985.uk/ronald1985/Eye-Reminder/icons/disabledicon"
	enabledicon "gitea.ronald1985.uk/ronald1985/Eye-Reminder/icons/enabledicon"

	"github.com/gen2brain/beeep"
	"github.com/gen2brain/malgo"
	"github.com/getlantern/systray"
	ge "github.com/ronaldr1985/graceful-exit"
	"github.com/youpy/go-wav"
	"gopkg.in/yaml.v3"
)

const (
	DEFAULT_TIME_INBETWEEN_NOTIFICATIONS = 20 * time.Minute
	EYE_REMINDER_ICON_URL                = "https://gitea.ronald1985.uk/ronald1985/Eye-Reminder/raw/branch/master/assets/Eye-Reminder-Icon.png"
	DEFAULT_CONFIG_FILE                  = "Interval: 20\nSoundEnabled: false\nMP3File: \"\""
)

type Config struct {
	Interval      int    `yaml:"Interval"`
	SoundEnabled  bool   `yaml:"SoundEnabled"`
	WAVFile       string `yaml:"MP3File"`
	imageLocation string
}

var (
	DEFAULT_UNIX_DIRECTORY    = os.Getenv("HOME") + "/.config/Eye-Reminder/"
	DEFAULT_WINDOWS_DIRECTORY = os.Getenv("LOCALAPPDATA") + "/Eye-Reminder/"
	ProgramConfig             Config
)

func print_fatal_error(err ...string) {
	fmt.Fprintln(os.Stderr, err)
	os.Exit(1)
}

func ReadConfig(filename string) (Config, error) {
	config := &Config{}

	bytes, err := os.ReadFile(filename)
	if err != nil {
		return *config, err
	}

	err = yaml.Unmarshal(bytes, config)
	if err != nil {
		return *config, fmt.Errorf("in file %q: %w", filename, err)
	}

	return *config, err
}

func CheckIfFileExists(filename string) (bool, error) {
	if _, err := os.Stat(filename); err == nil {
		return true, nil
	} else if errors.Is(err, os.ErrNotExist) {
		return false, nil
	} else {
		return false, err
	}
}

func DownloadFile(filename, url string) bool {
	out, err := os.Create(filename)
	if err != nil {
		return false
	}
	defer out.Close()

	resp, err := http.Get(url)
	if err != nil {
		out.Close()
		os.Remove(filename)
		return false
	}
	defer resp.Body.Close()

	_, err = io.Copy(out, resp.Body)
	if err != nil {
		return false
	}

	return true
}

func SendNotification(title string, message string) bool {
	path, err := exec.LookPath("herbe")
	if err == nil {
		var args []string
		args = append(args, title, message)
		cmd := exec.Command(path, args...)
		err := cmd.Start()
		if err != nil {
			return false
		}
	} else if strings.Contains(err.Error(), "executable file not found in ") {
		err := beeep.Notify(title, message, "assets/Eye-Reminder-Icon.png")
		if err != nil {
			return false
		}
	}

	return true
}

func PlayWAVFile(filename string, stopPlaying *bool) error {
	file, err := os.Open(filename)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
	defer file.Close()

	w := wav.NewReader(file)
	f, err := w.Format()
	if err != nil {
		return err
	}

	reader := w
	channels := uint32(f.NumChannels)
	sampleRate := f.SampleRate

	ctx, err := malgo.InitContext(nil, malgo.ContextConfig{}, func(message string) {
		fmt.Printf("LOG <%v>\n", message)
	})
	if err != nil {
		return err
	}
	defer func() {
		_ = ctx.Uninit()
		ctx.Free()
	}()

	deviceConfig := malgo.DefaultDeviceConfig(malgo.Playback)
	deviceConfig.Playback.Format = malgo.FormatS16
	deviceConfig.Playback.Channels = channels
	deviceConfig.SampleRate = sampleRate
	deviceConfig.Alsa.NoMMap = 1

	// This is the function that's used for sending more data to the device for playback.
	onSamples := func(pOutputSample, pInputSamples []byte, framecount uint32) {
		io.ReadFull(reader, pOutputSample)
	}

	deviceCallbacks := malgo.DeviceCallbacks{
		Data: onSamples,
	}
	device, err := malgo.InitDevice(ctx.Context, deviceConfig, deviceCallbacks)
	if err != nil {
		return err
	}
	defer device.Uninit()

	err = device.Start()
	if err != nil {
		return err
	}

	for device.IsStarted() {
		if *stopPlaying {
			break
		}
	}

	return nil
}

func systrayOnReady() {
	var enabled bool = true
	var notificationsEnabled bool = true
	var soundEnabled bool = ProgramConfig.SoundEnabled
	var stopSound bool = false
	systray.SetTitle("Eye Reminder")
	systray.SetTooltip("Eye Reminder")
	systray.SetIcon(enabledicon.Data)
	systray.AddSeparator()
	mEnabled := systray.AddMenuItemCheckbox(
		"Enabled", "Disables notifications and sound", true,
	)
	systray.AddSeparator()
	mStopSound := systray.AddMenuItem(
		"Stop sound", "Stops the sound that is currently being played",
	)
	mStopSound.Disable()
	mNotificationsEnabled := systray.AddMenuItemCheckbox(
		"Notifications enabled", "Whether notifications are enabled", true,
	)
	mSoundEnabled := systray.AddMenuItemCheckbox(
		"Enabled", "Whether sound is played", true,
	)
	systray.AddSeparator()
	mQuitOrig := systray.AddMenuItem("Quit", "Quit the whole app")

	go func() {
		<-mQuitOrig.ClickedCh
		fmt.Println("Requesting quit")
		systray.Quit()
		fmt.Println("Finished quitting")
	}()

	go func() {
		lastTimeNotificationWasSent := time.Now().Add(time.Duration(-ProgramConfig.Interval) * time.Minute)

		for {
			if enabled && time.Since(lastTimeNotificationWasSent) > time.Duration(ProgramConfig.Interval)*time.Minute {
				if notificationsEnabled {
					fmt.Println("Sending notification")

					SendNotification("Eye Reminder", "Look away for the screen for atleast 20 seconds")
				}
				if soundEnabled {
					fmt.Println("Playing sound file")

					mStopSound.Enable()

					PlayWAVFile(ProgramConfig.WAVFile, &stopSound)
					mStopSound.Disable()
					stopSound = false
				}

				lastTimeNotificationWasSent = time.Now()
			}
		}
	}()

	go func() {
		for {
			select {
			case <-mEnabled.ClickedCh:
				if mEnabled.Checked() {
					mEnabled.Uncheck()

					enabled = false

					systray.SetIcon(disabledicon.Data)
				} else {
					mEnabled.Check()

					enabled = true

					systray.SetIcon(enabledicon.Data)
				}
			case <-mNotificationsEnabled.ClickedCh:
				if mNotificationsEnabled.Checked() {
					mNotificationsEnabled.Uncheck()

					notificationsEnabled = false
				} else {
					mNotificationsEnabled.Check()

					notificationsEnabled = true
				}
			case <-mSoundEnabled.ClickedCh:
				if mSoundEnabled.Checked() {
					mSoundEnabled.Uncheck()

					soundEnabled = false
				} else {
					mSoundEnabled.Check()

					soundEnabled = false
				}
			case <-mStopSound.ClickedCh:
				stopSound = true
			}
		}
	}()
}

func main() {
	ge.HandleSignals(false)

	ProgramConfig.Interval = int(DEFAULT_TIME_INBETWEEN_NOTIFICATIONS)

	var possibleAppDirectoryLocations []string
	possibleAppDirectoryLocations = append(possibleAppDirectoryLocations, os.Getenv("HOME")+"/.config/Eye-Reminder/")
	possibleAppDirectoryLocations = append(possibleAppDirectoryLocations, os.Getenv("HOME")+"/.config/Eye-Reminder/")
	possibleAppDirectoryLocations = append(possibleAppDirectoryLocations, os.Getenv("XDG_CONFIG_HOME")+"/Eye-Reminder/")
	possibleAppDirectoryLocations = append(possibleAppDirectoryLocations, os.Getenv("XDG_CONFIG_HOME")+"/Eye-Reminder/")
	possibleAppDirectoryLocations = append(possibleAppDirectoryLocations, os.Getenv("LOCALAPPDATA")+"/Eye-Reminder/")
	possibleAppDirectoryLocations = append(possibleAppDirectoryLocations, os.Getenv("LOCALAPPDATA")+"/Eye-Reminder/")

	appDirectory := "not found"
	for _, folder := range possibleAppDirectoryLocations {
		if _, err := os.Stat(folder); !os.IsNotExist(err) {
			appDirectory = folder
			break
		}
	}

	if appDirectory == "not found" {
		if runtime.GOOS == "windows" {
			appDirectory = DEFAULT_WINDOWS_DIRECTORY
		} else {
			appDirectory = DEFAULT_UNIX_DIRECTORY
		}

		fmt.Println("Creating config directory:", appDirectory)
		err := os.Mkdir(appDirectory, 0755)
		fmt.Println("Created folder:", appDirectory)
		if err != nil {
			panic(err)
		}
	}

	configFile := ""
	if fileExists, err := CheckIfFileExists(appDirectory + "config.yaml"); fileExists {
		configFile = appDirectory + "config.yaml"
	} else if !fileExists && err == nil {
		if fileExists, _ := CheckIfFileExists(appDirectory + "config.yml"); fileExists {
			configFile = appDirectory + "config.yml"
		}
	}

	if configFile != "" {
		fmt.Println("Found config file at", configFile)
	}

	if configFile == "" {
		configFile = appDirectory + "config.yaml"

		fmt.Println("Creating config file:", configFile)
		f, err := os.Create(configFile)
		if err != nil {
			print_fatal_error("Failed to create config file")
		}
		fmt.Println("Created config file:", configFile)

		fmt.Println("Writing default config to", configFile)
		_, err = f.WriteString(DEFAULT_CONFIG_FILE)
		if err != nil {
			f.Close()
			print_fatal_error("Failed to write to config file: ", configFile)
		}
		f.Close()

		fmt.Println("Written default config to ", configFile)
	}

	var err error
	ProgramConfig, err = ReadConfig(configFile)
	if err != nil {
		print_fatal_error("Failed to read config file")
	}

	ProgramConfig.imageLocation = appDirectory + "Eye-Reminder-Icon.png"
	if fileExists, err := CheckIfFileExists(ProgramConfig.imageLocation); !fileExists && err == nil {
		fmt.Println("Downloading icon")
		DownloadFile(ProgramConfig.imageLocation, EYE_REMINDER_ICON_URL)
		fmt.Println("Downloaded icon")
	} else if err != nil {
		print_fatal_error("Failed to check if ", ProgramConfig.imageLocation, " exists.")
	}

	systrayOnExit := func() {
	}
	systray.Run(systrayOnReady, systrayOnExit)
}