package repository

import (
	"butterfliu/internal/model"
	"database/sql"
)

type LibraryRepository struct {
	db *sql.DB
}

func NewLibraryRepository(db *sql.DB) *LibraryRepository {
	return &LibraryRepository{db: db}
}

func (r *LibraryRepository) GetAll() ([]model.Library, error) {
	rows, err := r.db.Query("SELECT id, name, path, created_at, updated_at FROM libraries")
	if err != nil {
		return nil, err
	}
	defer rows.Close()

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

	return libraries, nil
}

func (r *LibraryRepository) GetByID(id int) (model.Library, error) {
	row := r.db.QueryRow("SELECT id, name, path, COALESCE(created_at, '1970-01-01T00:00:00Z'), COALESCE(updated_at, '1970-01-01T00:00:00Z') FROM libraries WHERE id = ?", id)
	var lib model.Library
	if err := row.Scan(&lib.ID, &lib.Name, &lib.Path, &lib.CreatedAt, &lib.UpdatedAt); err != nil {
		return model.Library{}, err
	}
	return lib, nil
}

func (r *LibraryRepository) Create(name, path string) (model.Library, error) {
	result, err := r.db.Exec("INSERT INTO libraries (name, path) VALUES (?, ?)", name, path)
	if err != nil {
		return model.Library{}, err
	}

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

	return model.Library{
		ID:   int(id),
		Name: name,
		Path: path,
	}, nil
}

func (r *LibraryRepository) UpdateName(id int, name string) error {
	_, err := r.db.Exec("UPDATE libraries SET name = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?", name, id)
	return err
}

func (r *LibraryRepository) UpdatePath(id int, path string) error {
	_, err := r.db.Exec("UPDATE libraries SET path = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?", path, id)
	return err
}

func (r *LibraryRepository) Delete(id int) error {
	tx, err := r.db.Begin()
	if err != nil {
		return err
	}
	defer tx.Rollback()

	_, err = tx.Exec("DELETE FROM libraries WHERE id = ?", id)
	if err != nil {
		return err
	}

	if err := cleanupOrphansTx(tx); err != nil {
		return err
	}

	return tx.Commit()
}

func (r *LibraryRepository) CleanupOrphans() error {
	tx, err := r.db.Begin()
	if err != nil {
		return err
	}
	defer tx.Rollback()

	if err := cleanupOrphansTx(tx); err != nil {
		return err
	}

	return tx.Commit()
}

func cleanupOrphansTx(tx *sql.Tx) error {
	_, err := tx.Exec(`
		DELETE FROM albums WHERE id NOT IN (
			SELECT DISTINCT album_id FROM songs WHERE album_id IS NOT NULL
		)
	`)
	if err != nil {
		return err
	}

	_, err = tx.Exec(`
		DELETE FROM artists WHERE id NOT IN (
			SELECT DISTINCT artist_id FROM songs WHERE artist_id IS NOT NULL
			UNION
			SELECT DISTINCT artist_id FROM albums WHERE artist_id IS NOT NULL
		)
	`)
	if err != nil {
		return err
	}

	return nil
}