package backend

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"time"
)

type DeezerDownloader struct {
	client *http.Client
}

func NewDeezerDownloader() *DeezerDownloader {
	return &DeezerDownloader{
		client: &http.Client{
			Timeout: 300 * time.Second,
		},
	}
}

type YoinkifyRequest struct {
	URL         string `json:"url"`
	Format      string `json:"format"`
	GenreSource string `json:"genreSource"`
}

func (d *DeezerDownloader) DownloadFromYoinkify(spotifyURL, outputDir string) (string, error) {
	apiURL := "https://yoinkify.lol/api/download"

	payload := YoinkifyRequest{
		URL:         spotifyURL,
		Format:      "flac",
		GenreSource: "spotify",
	}

	jsonData, err := json.Marshal(payload)
	if err != nil {
		return "", err
	}

	req, err := http.NewRequest("POST", apiURL, bytes.NewBuffer(jsonData))
	if err != nil {
		return "", err
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36")

	fmt.Printf("Fetching from Deezer API (Yoinkify)...\n")
	resp, err := d.client.Do(req)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	if resp.StatusCode != 200 {
		return "", fmt.Errorf("Deezer API returned status %d", resp.StatusCode)
	}

	tempFileName := fmt.Sprintf("deezer_%d.flac", time.Now().UnixNano())
	filePath := filepath.Join(outputDir, tempFileName)

	out, err := os.Create(filePath)
	if err != nil {
		return "", err
	}
	defer out.Close()

	fmt.Printf("Downloading track from Deezer...\n")
	pw := NewProgressWriter(out)
	_, err = io.Copy(pw, resp.Body)
	if err != nil {
		out.Close()
		os.Remove(filePath)
		return "", err
	}

	fmt.Printf("\rDownloaded: %.2f MB (Complete)\n", float64(pw.GetTotal())/(1024*1024))
	return filePath, nil
}

func (d *DeezerDownloader) Download(spotifyID, outputDir, filenameFormat, playlistName, playlistOwner string, includeTrackNumber bool, position int, spotifyTrackName, spotifyArtistName, spotifyAlbumName, spotifyAlbumArtist, spotifyReleaseDate, spotifyCoverURL string, spotifyTrackNumber, spotifyDiscNumber, spotifyTotalTracks int, embedMaxQualityCover bool, spotifyTotalDiscs int, spotifyCopyright, spotifyPublisher, spotifyURL string, useFirstArtistOnly bool, useSingleGenre bool, embedGenre bool) (string, error) {

	if outputDir != "." {
		if err := os.MkdirAll(outputDir, 0755); err != nil {
			return "", fmt.Errorf("failed to create output directory: %w", err)
		}
	}

	if spotifyTrackName != "" && spotifyArtistName != "" {
		filenameArtist := spotifyArtistName
		filenameAlbumArtist := spotifyAlbumArtist
		if useFirstArtistOnly {
			filenameArtist = GetFirstArtist(spotifyArtistName)
			filenameAlbumArtist = GetFirstArtist(spotifyAlbumArtist)
		}
		expectedFilename := BuildExpectedFilename(spotifyTrackName, filenameArtist, spotifyAlbumName, filenameAlbumArtist, spotifyReleaseDate, filenameFormat, playlistName, playlistOwner, includeTrackNumber, position, spotifyDiscNumber, false)
		expectedPath := filepath.Join(outputDir, expectedFilename)

		if fileInfo, err := os.Stat(expectedPath); err == nil && fileInfo.Size() > 0 {
			fmt.Printf("File already exists: %s (%.2f MB)\n", expectedPath, float64(fileInfo.Size())/(1024*1024))
			return "EXISTS:" + expectedPath, nil
		}
	}

	type mbResult struct {
		ISRC     string
		Metadata Metadata
	}

	metaChan := make(chan mbResult, 1)
	if (embedGenre || true) && spotifyURL != "" {
		go func() {
			res := mbResult{}
			var isrc string
			parts := strings.Split(spotifyURL, "/")
			if len(parts) > 0 {
				sID := strings.Split(parts[len(parts)-1], "?")[0]
				if sID != "" {
					client := NewSongLinkClient()
					if val, err := client.GetISRC(sID); err == nil {
						isrc = val
					}
				}
			}
			res.ISRC = isrc
			if isrc != "" && embedGenre {
				fmt.Println("Fetching MusicBrainz metadata...")
				if fetchedMeta, err := FetchMusicBrainzMetadata(isrc, spotifyTrackName, spotifyArtistName, spotifyAlbumName, useSingleGenre, embedGenre); err == nil {
					res.Metadata = fetchedMeta
					fmt.Println("✓ MusicBrainz metadata fetched")
				} else {
					fmt.Printf("Warning: Failed to fetch MusicBrainz metadata: %v\n", err)
				}
			}
			metaChan <- res
		}()
	} else {
		close(metaChan)
	}

	filePath, err := d.DownloadFromYoinkify(spotifyURL, outputDir)
	if err != nil {
		return "", err
	}

	var isrc string
	var mbMeta Metadata
	if spotifyURL != "" {
		result := <-metaChan
		isrc = result.ISRC
		mbMeta = result.Metadata
	}

	if spotifyTrackName != "" && spotifyArtistName != "" {
		safeArtist := sanitizeFilename(spotifyArtistName)
		safeAlbumArtist := sanitizeFilename(spotifyAlbumArtist)

		if useFirstArtistOnly {
			safeArtist = sanitizeFilename(GetFirstArtist(spotifyArtistName))
			safeAlbumArtist = sanitizeFilename(GetFirstArtist(spotifyAlbumArtist))
		}

		safeTitle := sanitizeFilename(spotifyTrackName)
		safeAlbum := sanitizeFilename(spotifyAlbumName)

		year := ""
		if len(spotifyReleaseDate) >= 4 {
			year = spotifyReleaseDate[:4]
		}

		var newFilename string

		if strings.Contains(filenameFormat, "{") {
			newFilename = filenameFormat
			newFilename = strings.ReplaceAll(newFilename, "{title}", safeTitle)
			newFilename = strings.ReplaceAll(newFilename, "{artist}", safeArtist)
			newFilename = strings.ReplaceAll(newFilename, "{album}", safeAlbum)
			newFilename = strings.ReplaceAll(newFilename, "{album_artist}", safeAlbumArtist)
			newFilename = strings.ReplaceAll(newFilename, "{year}", year)
			newFilename = strings.ReplaceAll(newFilename, "{date}", SanitizeFilename(spotifyReleaseDate))

			if spotifyDiscNumber > 0 {
				newFilename = strings.ReplaceAll(newFilename, "{disc}", fmt.Sprintf("%d", spotifyDiscNumber))
			} else {
				newFilename = strings.ReplaceAll(newFilename, "{disc}", "")
			}

			if position > 0 {
				newFilename = strings.ReplaceAll(newFilename, "{track}", fmt.Sprintf("%02d", position))
			} else {
				newFilename = strings.ReplaceAll(newFilename, "{track}", "")
			}
		} else {
			switch filenameFormat {
			case "artist-title":
				newFilename = fmt.Sprintf("%s - %s", safeArtist, safeTitle)
			case "title":
				newFilename = safeTitle
			default:
				newFilename = fmt.Sprintf("%s - %s", safeTitle, safeArtist)
			}

			if includeTrackNumber && position > 0 {
				newFilename = fmt.Sprintf("%02d. %s", position, newFilename)
			}
		}

		ext := ".flac"
		newFilename = newFilename + ext
		newFilePath := filepath.Join(outputDir, newFilename)

		if err := os.Rename(filePath, newFilePath); err != nil {
			fmt.Printf("Warning: Failed to rename file: %v\n", err)
		} else {
			filePath = newFilePath
			fmt.Printf("Renamed to: %s\n", newFilename)
		}
	}

	fmt.Println("Embedding Spotify metadata...")

	coverPath := ""
	if spotifyCoverURL != "" {
		coverPath = filePath + ".cover.jpg"
		coverClient := NewCoverClient()
		if err := coverClient.DownloadCoverToPath(spotifyCoverURL, coverPath, embedMaxQualityCover); err != nil {
			fmt.Printf("Warning: Failed to download Spotify cover: %v\n", err)
			coverPath = ""
		} else {
			defer os.Remove(coverPath)
			fmt.Println("Spotify cover downloaded")
		}
	}

	trackNumberToEmbed := spotifyTrackNumber
	if trackNumberToEmbed == 0 {
		trackNumberToEmbed = 1
	}

	metadata := Metadata{
		Title:       spotifyTrackName,
		Artist:      spotifyArtistName,
		Album:       spotifyAlbumName,
		AlbumArtist: spotifyAlbumArtist,
		Date:        spotifyReleaseDate,
		TrackNumber: trackNumberToEmbed,
		TotalTracks: spotifyTotalTracks,
		DiscNumber:  spotifyDiscNumber,
		TotalDiscs:  spotifyTotalDiscs,
		URL:         spotifyURL,
		Copyright:   spotifyCopyright,
		Publisher:   spotifyPublisher,
		Description: "https://github.com/afkarxyz/SpotiFLAC",
		ISRC:        isrc,
		Genre:       mbMeta.Genre,
	}

	if err := EmbedMetadataToConvertedFile(filePath, metadata, coverPath); err != nil {
		fmt.Printf("Warning: Failed to embed metadata: %v\n", err)
	} else {
		fmt.Println("Metadata embedded successfully")
	}

	fmt.Println("Done")
	fmt.Println("✓ Downloaded successfully from Deezer")
	return filePath, nil
}