package main

import (
	"butterfliu/migrations"
	"database/sql"
	"fmt"
	"log"
	"os"
	"path/filepath"
)

var DB *sql.DB

func GetDB() *sql.DB {
	return DB
}

func InitDB(dbPath string) error {
	dir := filepath.Dir(dbPath)
	if _, err := os.Stat(dir); os.IsNotExist(err) {
		if err := os.MkdirAll(dir, 0755); err != nil {
			return fmt.Errorf("failed to create database directory %s: %v", dir, err)
		}
	}

	var err error

	DB, _ = sql.Open("sqlite3", dbPath)

	DB.Ping()

	if err = migrations.InitMigrationTable(DB); err != nil {
		return fmt.Errorf("failed to initialize migration table: %v", err)
	}

	// Auto-migrate by default, can be disabled with AUTO_MIGRATE=false
	if os.Getenv("AUTO_MIGRATE") != "false" {
		log.Println("Auto-migration enabled, applying pending migrations...")
		if err = migrations.MigrateUp(DB); err != nil {
			log.Printf("Warning: Auto migration failed: %v", err)
		} else {
			log.Println("Auto-migration completed successfully")
		}
	} else {
		log.Println("Auto-migration disabled")
	}

	return nil
}

func CloseDB() error {
	if DB != nil {
		return DB.Close()
	}
	return nil
}

func AddLibrary(name, path string) (Library, error) {
	absPath, err := filepath.Abs(path)
	if err != nil {
		return Library{}, err
	}

	result, err := DB.Exec(
		"INSERT INTO libraries (name, path) VALUES (?, ?)",
		name, absPath,
	)
	if err != nil {
		return Library{}, err
	}

	id, err := result.LastInsertId()
	if err != nil {
		return Library{}, err
	}

	return Library{
		ID:   int(id),
		Name: name,
		Path: absPath,
	}, nil
}

func GetLibraries() ([]Library, error) {
	rows, err := DB.Query("SELECT id, name, path FROM libraries")
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	libraries := []Library{}
	for rows.Next() {
		var lib Library
		if err := rows.Scan(&lib.ID, &lib.Name, &lib.Path); err != nil {
			return nil, err
		}
		libraries = append(libraries, lib)
	}

	return libraries, nil
}

func GetLibraryByID(id int) (Library, error) {
	row := DB.QueryRow("SELECT id, name, path FROM libraries WHERE id = ?", id)
	var lib Library
	if err := row.Scan(&lib.ID, &lib.Name, &lib.Path); err != nil {
		return Library{}, err
	}
	return lib, nil
}

func UpdateLibraryName(id int, name string) error {
	_, err := DB.Exec(
		"UPDATE libraries SET name = ? WHERE id = ?",
		name, id,
	)
	return err
}
func UpdateLibraryPath(id int, path string) error {
	_, err := DB.Exec(
		"UPDATE libraries SET path = ? WHERE id = ?",
		path, id,
	)
	return err
}
func DeleteLibrary(id int) error {
	_, err := DB.Exec("DELETE FROM libraries WHERE id = ?", id)
	return err
}

func AddMediaFile(path string, libraryID int) (MediaFile, error) {
	result, err := DB.Exec("INSERT INTO media_files (path, library_id) VALUES (?, ?)", path, libraryID)
	if err != nil {
		return MediaFile{}, err
	}

	id, err := result.LastInsertId()
	if err != nil {
		return MediaFile{}, err
	}

	return MediaFile{
		ID:   int(id),
		Path: path,
	}, nil
}

func GetMediaFileByPath(path string) (MediaFile, error) {
	row := DB.QueryRow("SELECT id, path FROM media_files WHERE path = ?", path)
	var mediaFile MediaFile
	if err := row.Scan(&mediaFile.ID, &mediaFile.Path); err != nil {
		return MediaFile{}, err
	}
	return mediaFile, nil
}

func AddArtist(name string) (Artist, error) {
	result, err := DB.Exec("INSERT INTO artists (name) VALUES (?)", name)
	if err != nil {
		return Artist{}, err
	}

	id, err := result.LastInsertId()
	if err != nil {
		return Artist{}, err
	}

	return Artist{
		ID:   int(id),
		Name: name,
	}, nil
}

func GetArtists() ([]Artist, error) {
	rows, err := DB.Query("SELECT id, name FROM artists")
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	artists := []Artist{}
	for rows.Next() {
		var artist Artist
		if err := rows.Scan(&artist.ID, &artist.Name); err != nil {
			return nil, err
		}
		artists = append(artists, artist)
	}
	return artists, nil
}
func GetArtistByID(id int) (Artist, error) {
	row := DB.QueryRow("SELECT id, name FROM artists WHERE id = ?", id)
	var artist Artist
	if err := row.Scan(&artist.ID, &artist.Name); err != nil {
		return Artist{}, err
	}
	return artist, nil
}
func GetArtistByName(name string) (Artist, error) {
	row := DB.QueryRow("SELECT id, name FROM artists WHERE name = ?", name)
	var artist Artist
	if err := row.Scan(&artist.ID, &artist.Name); err != nil {
		return Artist{}, err
	}
	return artist, nil
}
func UpdateArtistName(id int, name string) error {
	_, err := DB.Exec("UPDATE artists SET name = ? WHERE id = ?", name, id)
	return err
}

func DeleteArtist(id int) error {
	_, err := DB.Exec("DELETE FROM artists WHERE id = ?", id)
	return err
}

func AddAlbum(title string, artistID int) (Album, error) {
	result, err := DB.Exec("INSERT INTO albums (title, artist_id) VALUES (?, ?)", title, artistID)
	if err != nil {
		return Album{}, err
	}
	id, err := result.LastInsertId()
	if err != nil {
		return Album{}, err
	}

	return Album{
		ID:       int(id),
		Title:    title,
		ArtistID: artistID,
	}, nil
}

func GetAlbums() ([]Album, error) {
	rows, err := DB.Query("SELECT id, title, artist_id FROM albums")
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	albums := []Album{}
	for rows.Next() {
		var album Album
		if err := rows.Scan(&album.ID, &album.Title, &album.ArtistID); err != nil {
			return nil, err
		}
		albums = append(albums, album)
	}
	return albums, nil
}

func GetAlbumByID(id int) (Album, error) {
	row := DB.QueryRow("SELECT id, title, artist_id FROM albums WHERE id = ?", id)
	var album Album
	if err := row.Scan(&album.ID, &album.Title, &album.ArtistID); err != nil {
		return Album{}, err
	}
	return album, nil
}

func GetAlbumByTitle(title string) (Album, error) {
	row := DB.QueryRow("SELECT id, title, artist_id FROM albums WHERE title = ?", title)
	var album Album
	if err := row.Scan(&album.ID, &album.Title, &album.ArtistID); err != nil {
		return Album{}, err
	}
	return album, nil
}

func GetAlbumByTitleAndArtist(title string, artistID int) (Album, error) {
	row := DB.QueryRow("SELECT id, title, artist_id FROM albums WHERE title = ? AND artist_id = ?", title, artistID)
	var album Album
	if err := row.Scan(&album.ID, &album.Title, &album.ArtistID); err != nil {
		return Album{}, err
	}
	return album, nil
}

func GetAlbumsByArtist(artistID int) ([]Album, error) {
	rows, err := DB.Query("SELECT id, title, artist_id FROM albums WHERE artist_id = ?", artistID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	albums := []Album{}
	for rows.Next() {
		var album Album
		if err := rows.Scan(&album.ID, &album.Title, &album.ArtistID); err != nil {
			return nil, err
		}
		albums = append(albums, album)
	}
	return albums, nil
}

func UpdateAlbumTitle(id int, title string) error {
	_, err := DB.Exec("UPDATE albums SET title = ? WHERE id = ?", title, id)
	return err
}
func UpdateAlbumArtistID(id, artistID int) error {
	_, err := DB.Exec("UPDATE albums SET artist_id = ?", artistID)
	return err
}
func DeleteAlbum(id int) error {
	_, err := DB.Exec("DELETE FROM albums WHERE id = ?", id)
	return err
}

func AddSong(title string, artistID, albumID, duration, mediaFileID int) (Song, error) {
	result, err := DB.Exec("INSERT INTO songs (title, artist_id, album_id, duration, media_file_id) VALUES (?, ?, ?, ?, ?)", title, artistID, albumID, duration, mediaFileID)
	if err != nil {
		return Song{}, err
	}

	id, err := result.LastInsertId()
	if err != nil {
		return Song{}, err
	}

	return Song{
		ID:          int(id),
		Title:       title,
		ArtistID:    artistID,
		AlbumID:     albumID,
		Duration:    duration,
		MediaFileID: mediaFileID,
	}, nil
}
func GetSongs() ([]Song, error) {
	rows, err := DB.Query("SELECT id, artist_id, album_id, duration, media_file_id FROM songs")
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	songs := []Song{}
	for rows.Next() {
		var song Song
		if err := rows.Scan(&song.ID, &song.ArtistID, &song.AlbumID, &song.Duration, &song.MediaFileID); err != nil {
			return nil, err
		}
		songs = append(songs, song)
	}
	return songs, nil
}
func UpdateSongTitle(id int, title string) error {
	_, err := DB.Exec("UPDATE songs SET title = ? WHERE id = ?", title, id)
	return err
}
func UpdateSongArtistID(id int, artistID int) error {
	_, err := DB.Exec("UPDATE songs SET artist_id = ?", artistID)
	return err
}
func UpdateSongAlbumID(id, albumID int) error {
	_, err := DB.Exec("UPDATE songs SET album_id = ?", albumID)
	return err
}
func UpdateSongDuration(id, duration int) error {
	_, err := DB.Exec("UPDATE songs SET duration = ?", duration)
	return err
}
func DeleteSong(id int) error {
	_, err := DB.Exec("DELETE FROM songs WHERE id = ?", id)
	return err
}

func GetSongsByLibrary(libraryID int) ([]Song, error) {
	rows, err := DB.Query(`
		SELECT s.id, s.title, s.artist_id, s.album_id, s.duration, s.media_file_id
		FROM songs s
		INNER JOIN media_files mf ON s.media_file_id = mf.id
		WHERE mf.library_id = ?
		ORDER BY s.title
	`, libraryID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	songs := []Song{}
	for rows.Next() {
		var song Song
		if err := rows.Scan(&song.ID, &song.Title, &song.ArtistID, &song.AlbumID, &song.Duration, &song.MediaFileID); err != nil {
			return nil, err
		}
		songs = append(songs, song)
	}
	return songs, nil
}

type SongDetail struct {
	ID       int    `json:"id"`
	Title    string `json:"title"`
	Artist   string `json:"artist"`
	Album    string `json:"album"`
	Duration int    `json:"duration"`
	Path     string `json:"path"`
}

func GetSongsByLibraryWithDetails(libraryID int) ([]SongDetail, error) {
	rows, err := DB.Query(`
		SELECT s.id, s.title, a.name as artist_name, al.title as album_title, s.duration, mf.path
		FROM songs s
		INNER JOIN media_files mf ON s.media_file_id = mf.id
		INNER JOIN artists a ON s.artist_id = a.id
		INNER JOIN albums al ON s.album_id = al.id
		WHERE mf.library_id = ?
		ORDER BY s.title
	`, libraryID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	songs := []SongDetail{}
	for rows.Next() {
		var song SongDetail
		if err := rows.Scan(&song.ID, &song.Title, &song.Artist, &song.Album, &song.Duration, &song.Path); err != nil {
			return nil, err
		}
		songs = append(songs, song)
	}
	return songs, nil
}

func GetAllSongsWithDetails() ([]SongDetail, error) {
	rows, err := DB.Query(`
		SELECT s.id, s.title, a.name as artist_name, al.title as album_title, s.duration, mf.path
		FROM songs s
		INNER JOIN media_files mf ON s.media_file_id = mf.id
		INNER JOIN artists a ON s.artist_id = a.id
		INNER JOIN albums al ON s.album_id = al.id
		ORDER BY s.title
	`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	songs := []SongDetail{}
	for rows.Next() {
		var song SongDetail
		if err := rows.Scan(&song.ID, &song.Title, &song.Artist, &song.Album, &song.Duration, &song.Path); err != nil {
			return nil, err
		}
		songs = append(songs, song)
	}
	return songs, nil
}