// 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.Collections.ObjectModel;
using System.Threading;
using System.Threading.Tasks;
using CommunityToolkit.Mvvm.Input;
using OwlCore.Provisos;
using StrixMusic.Sdk.AppModels;
using StrixMusic.Sdk.BaseModels;

namespace StrixMusic.Sdk.ViewModels
{
    /// <summary>
    /// An interfaced ViewModel for <see cref="ITrackCollection" />.
    /// This is needed so because multiple view models implement <see cref="ITrackCollection"/>,
    /// and the UI needs to create controls that handle only the ViewModels properties for an <see cref="ITrackCollection"/>.
    /// </summary>
    public interface ITrackCollectionViewModel : ISdkViewModel, ITrackCollection, IAsyncInit
    {
        /// <summary>
        /// The tracks in this collection.
        /// </summary>
        public ObservableCollection<TrackViewModel> Tracks { get; }

        /// <summary>
        /// Keeps the default track collection while sorting.
        /// </summary>
        public ObservableCollection<TrackViewModel> UnsortedTracks { get; }

        /// <summary>
        /// Populates the next set of tracks into the collection.
        /// </summary>
        /// <param name="limit">The number of items to load.</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>
        public Task PopulateMoreTracksAsync(int limit, CancellationToken cancellationToken = default);

        /// <summary>
        /// The current sorting type of tracks in the collection.
        /// </summary>
        public TrackSortingType CurrentTracksSortingType { get; }

        /// <summary>
        /// The current sorting direction of tracks in the collection. 
        /// </summary>
        public SortDirection CurrentTracksSortingDirection { get; }

        /// <summary>
        /// Sorts the track collection by <see cref="TrackSortingType"/>.
        /// </summary>
        /// <param name="trackSorting">The <see cref="TrackSortingType"/> by which to sort.</param>
        /// <param name="sortDirection">The direction by which to sort.</param>
        public void SortTrackCollection(TrackSortingType trackSorting, SortDirection sortDirection);
        
        /// <summary>
        /// Loads the entire collection of <see cref="ITrack"/>s and ensures all sources are merged.
        /// </summary>
        /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
        public Task InitTrackCollectionAsync(CancellationToken cancellationToken = default);
        
        /// <summary>
        /// Initializes the list of the <see cref="ITrack"/>.
        /// </summary>
        public IAsyncRelayCommand InitTrackCollectionAsyncCommand { get; }

        /// <inheritdoc cref="PopulateMoreTracksAsync" />
        public IAsyncRelayCommand<int> PopulateMoreTracksCommand { get; }

        /// <inheritdoc cref="ITrackCollectionBase.PlayTrackCollectionAsync"/>
        public IAsyncRelayCommand PlayTrackCollectionAsyncCommand { get; }

        /// <summary>
        /// Plays a single track from this track collection.
        /// </summary>
        public IAsyncRelayCommand<ITrack> PlayTrackAsyncCommand { get; }

        /// <inheritdoc cref="ITrackCollectionBase.PauseTrackCollectionAsync"/>
        public IAsyncRelayCommand PauseTrackCollectionAsyncCommand { get; }
        
        /// <summary>
        /// Sorts the collection with a new type.
        /// </summary>
        public IRelayCommand<TrackSortingType> ChangeTrackCollectionSortingTypeCommand { get; }
        
        /// <summary>
        /// Sorts the collection with a new direction.
        /// </summary>
        public IRelayCommand<SortDirection> ChangeTrackCollectionSortingDirectionCommand { get; }
    }
}