package migrations

import (
	"database/sql"
)

func init() {
	RegisterMigration(
		3,
		"Add metadata fields and timestamps",
		migrateAddMetadataUp,
		migrateAddMetadataDown,
	)
}

func migrateAddMetadataUp(tx *sql.Tx) error {
	// Add timestamps to libraries
	_, err := tx.Exec(`
		ALTER TABLE libraries ADD COLUMN created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
	`)
	if err != nil {
		return err
	}
	_, err = tx.Exec(`
		ALTER TABLE libraries ADD COLUMN updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
	`)
	if err != nil {
		return err
	}

	// Add metadata and timestamps to media_files
	_, err = tx.Exec(`
		ALTER TABLE media_files ADD COLUMN file_size INTEGER DEFAULT 0
	`)
	if err != nil {
		return err
	}
	_, err = tx.Exec(`
		ALTER TABLE media_files ADD COLUMN format TEXT DEFAULT ''
	`)
	if err != nil {
		return err
	}
	_, err = tx.Exec(`
		ALTER TABLE media_files ADD COLUMN bit_rate INTEGER DEFAULT 0
	`)
	if err != nil {
		return err
	}
	_, err = tx.Exec(`
		ALTER TABLE media_files ADD COLUMN sample_rate INTEGER DEFAULT 0
	`)
	if err != nil {
		return err
	}
	_, err = tx.Exec(`
		ALTER TABLE media_files ADD COLUMN created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
	`)
	if err != nil {
		return err
	}
	_, err = tx.Exec(`
		ALTER TABLE media_files ADD COLUMN updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
	`)
	if err != nil {
		return err
	}

	// Add fields to albums
	_, err = tx.Exec(`
		ALTER TABLE albums ADD COLUMN cover TEXT DEFAULT ''
	`)
	if err != nil {
		return err
	}
	_, err = tx.Exec(`
		ALTER TABLE albums ADD COLUMN year INTEGER DEFAULT 0
	`)
	if err != nil {
		return err
	}

	// Add fields to songs
	_, err = tx.Exec(`
		ALTER TABLE songs ADD COLUMN track_number INTEGER DEFAULT 0
	`)
	if err != nil {
		return err
	}
	_, err = tx.Exec(`
		ALTER TABLE songs ADD COLUMN disc_number INTEGER DEFAULT 0
	`)
	if err != nil {
		return err
	}
	_, err = tx.Exec(`
		ALTER TABLE songs ADD COLUMN genre TEXT DEFAULT ''
	`)
	if err != nil {
		return err
	}

	return nil
}

func migrateAddMetadataDown(tx *sql.Tx) error {
	// SQLite doesn't support DROP COLUMN in older versions, so we need to rebuild tables

	// Rebuild libraries
	_, err := tx.Exec(`
		CREATE TABLE libraries_old (
			id INTEGER PRIMARY KEY AUTOINCREMENT,
			name TEXT NOT NULL,
			path TEXT NOT NULL
		)
	`)
	if err != nil {
		return err
	}
	_, err = tx.Exec(`INSERT INTO libraries_old SELECT id, name, path FROM libraries`)
	if err != nil {
		return err
	}
	_, err = tx.Exec("DROP TABLE libraries")
	if err != nil {
		return err
	}
	_, err = tx.Exec("ALTER TABLE libraries_old RENAME TO libraries")
	if err != nil {
		return err
	}

	// Rebuild media_files
	_, err = tx.Exec(`
		CREATE TABLE media_files_old (
			id INTEGER PRIMARY KEY AUTOINCREMENT,
			path TEXT NOT NULL,
			library_id INTEGER NOT NULL,
			FOREIGN KEY (library_id) REFERENCES libraries(id) ON DELETE CASCADE
		)
	`)
	if err != nil {
		return err
	}
	_, err = tx.Exec(`INSERT INTO media_files_old SELECT id, path, library_id FROM media_files`)
	if err != nil {
		return err
	}
	_, err = tx.Exec("DROP TABLE media_files")
	if err != nil {
		return err
	}
	_, err = tx.Exec("ALTER TABLE media_files_old RENAME TO media_files")
	if err != nil {
		return err
	}

	// Rebuild albums
	_, err = tx.Exec(`
		CREATE TABLE albums_old (
			id INTEGER PRIMARY KEY AUTOINCREMENT,
			title TEXT NOT NULL,
			artist_id INTEGER,
			FOREIGN KEY (artist_id) REFERENCES artists(id),
			UNIQUE(title, artist_id)
		)
	`)
	if err != nil {
		return err
	}
	_, err = tx.Exec(`INSERT INTO albums_old SELECT id, title, artist_id FROM albums`)
	if err != nil {
		return err
	}
	_, err = tx.Exec("DROP TABLE albums")
	if err != nil {
		return err
	}
	_, err = tx.Exec("ALTER TABLE albums_old RENAME TO albums")
	if err != nil {
		return err
	}

	// Rebuild songs
	_, err = tx.Exec(`
		CREATE TABLE songs_old (
			id INTEGER PRIMARY KEY AUTOINCREMENT,
			title TEXT NOT NULL,
			album_id INTEGER,
			artist_id INTEGER,
			duration INTEGER,
			media_file_id INTEGER UNIQUE,
			FOREIGN KEY (album_id) REFERENCES albums(id),
			FOREIGN KEY (artist_id) REFERENCES artists(id),
			FOREIGN KEY (media_file_id) REFERENCES media_files(id) ON DELETE CASCADE
		)
	`)
	if err != nil {
		return err
	}
	_, err = tx.Exec(`INSERT INTO songs_old SELECT id, title, album_id, artist_id, duration, media_file_id FROM songs`)
	if err != nil {
		return err
	}
	_, err = tx.Exec("DROP TABLE songs")
	if err != nil {
		return err
	}
	_, err = tx.Exec("ALTER TABLE songs_old RENAME TO songs")
	if err != nil {
		return err
	}

	return nil
}