/// <summary>
/// Service to manage favorite movies using local storage
/// </summary>
/// <param name="localStorage">The local storage service</param>
class ManageFavorite(Blazored.LocalStorage.ILocalStorageService localStorage)
{
    // Inject the local storage service
    private readonly Blazored.LocalStorage.ILocalStorageService LocalStorage = localStorage;
    private readonly List<string> MoviesIDs = [];

    /// <summary>
    /// Load favorite movies from local storage
    /// Use Immediately after service instantiation otherwise the list will be empty
    /// </summary>
    /// <returns></returns>
    public async Task LoadFavorites()
    {
        var favorites = await LocalStorage.GetItemAsync<List<string>>("favorite") ?? [];
        MoviesIDs.Clear();
        MoviesIDs.AddRange(favorites);
    }

    /// <summary>
    /// Check if a movie is favorite or not
    /// </summary>
    /// <param name="movieID">The movie ID to check</param>
    /// <returns>True if the movie is favorite, otherwise false</returns>
    public bool IsFavorite(string movieID)
    {
        return MoviesIDs.Contains(movieID);
    }

    /// <summary>
    /// Toggle favorite status of a movie (by ID)
    /// </summary>
    /// <param name="movieID">The movie ID to toggle</param>
    /// <returns>The new favorite status</returns>
    public async Task<bool> ToggleFavoriteMovie(string movieID)
    {
        if (!IsFavorite(movieID))
        {
            MoviesIDs.Add(movieID);
        }
        else
        {
            MoviesIDs.RemoveAll(id => id == movieID);
        }

        await LocalStorage.SetItemAsync("favorite", MoviesIDs);
        return IsFavorite(movieID);
    }

    /// <summary>
    /// Get the list of favorite movie IDs
    /// </summary>
    /// <returns>The list of favorite movie IDs</returns>
    public List<string> GetFavoriteMovies()
    {
        return MoviesIDs;
    }
}