package yandex

import (
	"context"
	"errors"
	"fmt"
	"log/slog"
	"net/http"
	"os"
	"time"

	"ym-dl/internal/config"
	"gitea.mrixs.me/Mrixs/yandex-music-api-go/yandexmusic"
)

// TrackPosition represents track position in album
type TrackPosition struct {
	Volume int `json:"volume"`
	Index  int `json:"index"`
}

// YandexClient wraps the external yandexmusic client
type YandexClient struct {
	client     *yandexmusic.Client
	config     *config.YandexConfig
	httpClient *http.Client
	debug      bool
	logger     *slog.Logger
}

// NewYandexClient creates a new Yandex Music client wrapper
func NewYandexClient(cfg *config.YandexConfig, debug bool) (*YandexClient, error) {
	if cfg.Token == "" {
		return nil, errors.New("yandex.token is required")
	}

	httpClient := &http.Client{
		Timeout: 30 * time.Second,
	}

	logLevel := slog.LevelInfo
	if debug {
		logLevel = slog.LevelDebug
	}
	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{
		Level: logLevel,
	}))

	client := yandexmusic.NewClient(yandexmusic.ClientConfig{
		Token: cfg.Token,
	})

	if err := client.Init(context.Background()); err != nil {
		return nil, fmt.Errorf("init client: %w", err)
	}

	return &YandexClient{
		client:     client,
		config:     cfg,
		httpClient: httpClient,
		debug:      debug,
		logger:     logger,
	}, nil
}

// GetArtistTracks fetches tracks for an artist
func (c *YandexClient) GetArtistTracks(ctx context.Context, artistID int, page, pageSize int) ([]*yandexmusic.Track, error) {
	result, err := c.client.GetArtistTracks(ctx, fmt.Sprintf("%d", artistID), page, pageSize)
	if err != nil {
		return nil, err
	}
	tracks := make([]*yandexmusic.Track, 0, len(result.Tracks))
	for i := range result.Tracks {
		tracks = append(tracks, &result.Tracks[i])
	}
	return tracks, nil
}

// GetArtistAlbums fetches albums for an artist
func (c *YandexClient) GetArtistAlbums(ctx context.Context, artistID int, page, pageSize int) ([]*yandexmusic.Album, error) {
	result, err := c.client.GetArtistAlbums(ctx, fmt.Sprintf("%d", artistID), page, pageSize)
	if err != nil {
		return nil, err
	}
	albums := make([]*yandexmusic.Album, 0, len(result.Albums))
	for i := range result.Albums {
		albums = append(albums, &result.Albums[i])
	}
	return albums, nil
}

// GetAlbumWithTracks fetches an album with its tracks
func (c *YandexClient) GetAlbumWithTracks(ctx context.Context, albumID string) (*yandexmusic.Album, error) {
	albums, err := c.client.GetAlbumsWithTracks(ctx, []string{albumID})
	if err != nil {
		return nil, err
	}
	if len(albums) == 0 {
		return nil, fmt.Errorf("album not found")
	}
	return albums[0], nil
}

// GetTrackInfo fetches a single track's info
func (c *YandexClient) GetTrackInfo(ctx context.Context, trackID string) (*yandexmusic.Track, error) {
	return c.client.GetTrack(ctx, trackID)
}

// GetTrackInfoWithPosition fetches track info including track position in album
func (c *YandexClient) GetTrackInfoWithPosition(ctx context.Context, trackID string) (*yandexmusic.Track, *TrackPosition, error) {
	track, err := c.client.GetTrack(ctx, trackID)
	if err != nil {
		return nil, nil, err
	}

	// Extract track position from first album
	var position *TrackPosition
	if len(track.Albums) > 0 {
		albumID := string(track.Albums[0].ID)
		albums, err := c.client.GetAlbumsWithTracks(ctx, []string{albumID})
		if err == nil && len(albums) > 0 {
			album := albums[0]
			// Find track in album.Volumes and get position
			for volIdx, volume := range album.Volumes {
				for trackIdx, t := range volume {
					if string(t.ID) == trackID {
						position = &TrackPosition{
							Volume: volIdx + 1,
							Index:  trackIdx + 1,
						}
						break
					}
				}
				if position != nil {
					break
				}
			}
		}
	}

	return track, position, nil
}

// GetTrackDownloadInfo gets download info for a track
func (c *YandexClient) GetTrackDownloadInfo(ctx context.Context, trackID string) ([]yandexmusic.DownloadInfo, error) {
	return c.client.GetTrackDownloadInfo(ctx, trackID, "")
}

// GetArtistInfo fetches artist info
func (c *YandexClient) GetArtistInfo(ctx context.Context, artistID int) (*yandexmusic.Artist, error) {
	return c.client.GetArtist(ctx, fmt.Sprintf("%d", artistID))
}

// GetTrackDownloadURL gets the direct MP3 download URL for a track.
// Delegates to the library which handles XML download, parsing and URL signing.
func (c *YandexClient) GetTrackDownloadURL(ctx context.Context, trackID string) (string, error) {
	return c.client.GetTrackDownloadURL(ctx, trackID, "mp3", 0)
}