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/getlantern/systray"
	ge "github.com/ronaldr1985/graceful-exit"
	"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"
)

type Config struct {
	Interval      int `yaml:"Interval"`
	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 systrayOnReady() {
	var enabled bool = true
	systray.SetTitle("Eye Reminder")
	systray.SetTooltip("Eye Reminder")
	systray.SetIcon(enabledicon.Data)
	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) {
				fmt.Println("Sending notification")

				SendNotification("Eye Reminder", "Look away for the screen for atleast 20 seconds")

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

	go func() {
		systray.AddSeparator()
		mEnabled := systray.AddMenuItemCheckbox("Enabled", "Check Me", true)

		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)
				}
			}
		}
	}()
}

func main() {
	ge.HandleSignals(false)

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

	configFileLocation := "not found"

	for _, file := range possibleConfigFileLocations {
		if fileExists, err := CheckIfFileExists(file); fileExists {
			configFileLocation = file
			break
		} else if err != nil {
			fmt.Fprintln(os.Stderr, "Error checking for config file:", err)
		}
	}

	var err error
	appDirectory := "not found"
	if configFileLocation == "not found" {
		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/")

		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)
			}
		}

	} else {
		appDirectory = configFileLocation[:strings.IndexByte(configFileLocation, '/')+1]
		ProgramConfig, err = ReadConfig(configFileLocation)
		if err != nil {
			panic(err)
		}
	}

	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)
}