// Copyright (c) Arlo Godfrey. All Rights Reserved.
// Licensed under the GNU Lesser General Public License, Version 3.0 with additional terms.
// See the LICENSE, LICENSE.LESSER and LICENSE.ADDITIONAL files in the project root for more information.

using System;
using System.Threading;
using System.Threading.Tasks;
using StrixMusic.Sdk.AdapterModels;
using StrixMusic.Sdk.BaseModels;
using StrixMusic.Sdk.CoreModels;

namespace StrixMusic.Sdk.AppModels
{
    /// <summary>
    /// Represents an audio stream with metadata that belongs to an <see cref="ITrackCollection"/>.
    /// </summary>
    /// <remarks>Instances of this class may contain data merged from one or more sources.</remarks>
    public interface ITrack : ITrackBase, IArtistCollection, IGenreCollection, IPlayable, IAppModel, IMerged<ICoreTrack>
    {
        /// <summary>
        /// An <see cref="IAlbum"/> object that this track belongs to.
        /// </summary>
        IAlbum? Album { get; }

        /// <summary>
        /// The lyrics for this track.
        /// </summary>
        ILyrics? Lyrics { get; }

        /// <summary>
        /// An <see cref="IPlayableCollectionGroup"/> of items related to this item.
        /// </summary>
        #warning TODO needs a changed event to facilitate merging in new sources with non-null values.
        IPlayableCollectionGroup? RelatedItems { get; }

        /// <summary>
        /// Changes the <see cref="Lyrics"/> for this track.
        /// </summary>
        /// <param name="lyrics">The new lyrics data.</param>
        /// <param name="cancellationToken">A cancellation token that may be used to cancel the ongoing task.</param>
        /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
        Task ChangeLyricsAsync(ILyrics? lyrics, CancellationToken cancellationToken = default);

        /// <summary>
        /// Fires when the <see cref="Album"/> metadata changes.
        /// </summary>
        event EventHandler<IAlbum?>? AlbumChanged;

        /// <summary>
        /// Fires when the <see cref="Lyrics"/> metadata changes.
        /// </summary>
        event EventHandler<ILyrics?>? LyricsChanged;

        /// <summary>
        /// Changes the album for this track.
        /// </summary>
        /// <param name="album">The new album.</param>
        /// <param name="cancellationToken">A cancellation token that may be used to cancel the ongoing task.</param>
        /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
        Task ChangeAlbumAsync(IAlbum? album, CancellationToken cancellationToken = default);
    }
}