package download

import (
	"errors"
	log2 "log"
	"math/rand"
	"net/url"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"strings"
	"time"

	"watn3y.de/bloaterbot/botIO"
	"watn3y.de/bloaterbot/commonlogic"
	"watn3y.de/bloaterbot/config"

	tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api/v5"
	"github.com/rs/zerolog/log"
)

// TODO logging
// TODO error handling
// TODO rewrite
func Download(update tgbotapi.Update, bot *tgbotapi.BotAPI) {

	log.Debug().Int64("chat", update.Message.Chat.ID).Int64("user", update.Message.From.ID).Msg("starting download")

	commandArgs := strings.Fields(update.Message.CommandArguments())

	msg := tgbotapi.MessageConfig{
		BaseChat: tgbotapi.BaseChat{ChatID: update.Message.Chat.ID, ReplyToMessageID: update.Message.MessageID},
		Text:     "Downloading your YouTube Video...",
	}
	workingMessage := botIO.SendMessage(msg, bot)

	if len(commandArgs) >= 1 && matchURL(commandArgs[0]) != "" {

	} else {
		log.Error().Int64("chat", update.Message.Chat.ID).Int64("user", update.Message.From.ID).Str("args", update.Message.CommandArguments()).Msg("Failed to download YouTube Video. Empty args")
		message := tgbotapi.EditMessageTextConfig{
			BaseEdit: tgbotapi.BaseEdit{ChatID: workingMessage.Chat.ID, MessageID: workingMessage.MessageID},
			Text:     "Please specify a valid YouTube URL.",
		}
		botIO.EditMessage(message, bot)
		return
	}

	downloadTarget := randomString(20)

	downloaded := runYTDL(commandArgs[0], downloadTarget)

	if !downloaded {
		message := tgbotapi.EditMessageTextConfig{
			BaseEdit: tgbotapi.BaseEdit{ChatID: workingMessage.Chat.ID, MessageID: workingMessage.MessageID},
			Text:     "Something went wrong while downloading your media :(",
		}
		botIO.EditMessage(message, bot)
		return
	}

	files, err := os.ReadDir("data/videos/" + downloadTarget)

	if err != nil {
		log.Error().Err(err).Msg("failed to download. unable to read target directory")

		message := tgbotapi.EditMessageTextConfig{
			BaseEdit: tgbotapi.BaseEdit{ChatID: workingMessage.Chat.ID, MessageID: workingMessage.MessageID},
			Text:     "Something went wrong while downloading your media :(",
		}
		botIO.EditMessage(message, bot)
		return
	}

	if len(files) > 1 {
		log.Error().Err(err).Msg("failed to download. too many files")
		message := tgbotapi.EditMessageTextConfig{
			BaseEdit: tgbotapi.BaseEdit{ChatID: workingMessage.Chat.ID, MessageID: workingMessage.MessageID},
			Text:     "Something went wrong while downloading your media :(",
		}
		botIO.EditMessage(message, bot)
		return
	}

	message := tgbotapi.EditMessageTextConfig{
		BaseEdit: tgbotapi.BaseEdit{ChatID: workingMessage.Chat.ID, MessageID: workingMessage.MessageID},
		Text:     "Downloaded! Uploading now",
	}
	botIO.EditMessage(message, bot)

	serveMedia(update, bot, downloadTarget, files[0].Name())
	log.Debug().Str("URL", update.Message.CommandArguments()).Int64("user", update.Message.From.ID).Int64("chat", update.Message.Chat.ID).Msg("Served Video")
	time.Sleep(5 * time.Second)

	log.Info().Msg("downloaded file")
	bot.Send(tgbotapi.NewDeleteMessage(workingMessage.Chat.ID, workingMessage.MessageID))

}

func randomString(n int) string {
	rand.Seed(time.Now().UnixNano())
	var letters = []rune("1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
	b := make([]rune, n)
	for i := range b {
		b[i] = letters[rand.Intn(len(letters))]
	}
	return string(b)
}

func runYTDL(URL string, targetDir string) (success bool) {

	cmd := exec.Command("yt-dlp", "-f", "bv*[ext=mp4]+ba[ext=m4a] / bv*+ba/b", "--no-playlist", "-o", "data/videos/"+targetDir+"/"+"%(title)s.%(ext)s", "--write-thumbnail", "--convert-thumbnails", "jpg", "-o", "thumbnail:data/videos/"+targetDir+"thumb"+"/"+"%(title)s.%(ext)s", URL)

	out, err := cmd.CombinedOutput()
	var (
		ee *exec.ExitError
		pe *os.PathError
	)

	if errors.As(err, &ee) {
		log2.Println("[download.ytdl] Failed to download URL "+URL, " NON ZERO EXIT CODE: ", ee.ExitCode())
		success = false

	} else if errors.As(err, &pe) {
		log2.Println("[download.ytdl] Failed to download URL "+URL, " OS PATH ERROR: ", pe.Error())
		success = false

	} else if err != nil {
		log2.Println("[download.ytdl] Failed to download URL "+URL, " GENERAL ERROR: ", err.Error())
		success = false

	} else {
		log2.Println("[download.ytdl] Downloaded URL " + URL)
		success = true
	}

	if config.BotConfig.DebugMode {
		print(string(out))
	}

	return success
}

func matchURL(URL string) (matchedURL string) {
	parsedURL, err := url.Parse(URL)
	if err != nil {
		log.Err(err).Msg("Failed to parse URL")
		return ""
	}

	var domainRegex = regexp.MustCompile(`(youtube\.com$)|(youtu\.be$)`)

	m := domainRegex.FindStringSubmatch(parsedURL.Hostname())

	if len(m) >= 1 {
		return m[0]
	} else {
		return ""
	}

}

func serveMedia(update tgbotapi.Update, bot *tgbotapi.BotAPI, randomNoise string, file string) {
	fsPath := "data/videos/" + randomNoise + "/" + file
	fsThumbPath := "data/videos/" + randomNoise + "thumb" + "/" + strings.TrimSuffix(file, "mp4") + "jpg"
	fExt := filepath.Ext(fsPath)

	imageTypes := []string{".jpg", ".jpeg", ".png"}

	fsPathStat, _ := os.Stat(fsPath)

	if fsPathStat.Size() >= 52428800 {
		fExt = "thisfuckingshitistoobig"
	}

	if fExt == ".mp4" {
		vid := tgbotapi.VideoConfig{
			BaseFile:          tgbotapi.BaseFile{BaseChat: tgbotapi.BaseChat{ChatID: update.Message.Chat.ID, ReplyToMessageID: update.Message.MessageID}, File: tgbotapi.FilePath(fsPath)},
			Thumb:             tgbotapi.FilePath(fsThumbPath),
			Caption:           config.BotConfig.Download.Prefix + "/" + randomNoise + "/" + url.PathEscape(file),
			SupportsStreaming: true,
		}
		if _, err := os.Stat(fsThumbPath); err != nil {
			vid.Thumb = nil
		}
		botIO.SendVideo(vid, bot)

	} else if commonlogic.ContainsString(imageTypes, fExt) {
		pic := tgbotapi.PhotoConfig{
			BaseFile: tgbotapi.BaseFile{BaseChat: tgbotapi.BaseChat{ChatID: update.Message.Chat.ID, ReplyToMessageID: update.Message.MessageID}, File: tgbotapi.FilePath(fsPath)},
			Caption:  config.BotConfig.Download.Prefix + "/" + randomNoise + "/" + url.PathEscape(file),
		}
		botIO.SendPhoto(pic, bot)
	} else {
		message := tgbotapi.MessageConfig{
			BaseChat:              tgbotapi.BaseChat{ChatID: update.Message.Chat.ID, ReplyToMessageID: update.Message.MessageID},
			DisableWebPagePreview: false,
			ParseMode:             "html",
			Text:                  config.BotConfig.Download.Prefix + "/" + randomNoise + "/" + url.PathEscape(file),
		}
		botIO.SendMessage(message, bot)
	}
}