using Harmonia.Core.Engine;
using Harmonia.Core.Player;
using Harmonia.Core.Playlists;
using System.Linq;
using System.Threading.Tasks;

namespace Harmonia.WinUI.Session;

public class SessionRestorer(
    ISessionService sessionService,
    IPlaylistManager playlistManager,
    IAudioPlayer audioPlayer) : ISessionRestorer
{
    public async Task RestoreAsync()
    {
        RestorePlaylist();
        await RestoreAudioPlayerAsync();
    }

    private void RestorePlaylist()
    {
        PlaylistState playlistState = sessionService.Session.Playlist;

        if (string.IsNullOrWhiteSpace(playlistState.OpenPlaylistUID))
            return;

        Playlist? playlist = playlistManager.Playlists.FirstOrDefault(p => p.UID == playlistState.OpenPlaylistUID);

        if (playlist is null)
            return;

        playlistManager.CurrentPlaylist = playlist;
    }

    private async Task RestoreAudioPlayerAsync()
    {
        AudioPlayerState audioPlayerState = sessionService.Session.Player;
        audioPlayer.Volume = audioPlayerState.Volume;
        audioPlayer.IsMuted = audioPlayerState.IsMuted;

        if (string.IsNullOrWhiteSpace(audioPlayerState.PlaylistSongUID))
            return;

        Playlist? playlist = playlistManager.FindPlaylistContaining(audioPlayerState.PlaylistSongUID);

        if (playlist is null)
            return;

        PlaylistSong? playlistSong = playlist.Songs.FirstOrDefault(s => s.UID == audioPlayerState.PlaylistSongUID);

        if (playlistSong is null)
            return;

        await audioPlayer.LoadAsync(playlistSong, PlaybackMode.LoadOnly);

        if (audioPlayerState.Position > 0 && audioPlayerState.Position <= playlistSong.Song.Length.TotalSeconds)
            audioPlayer.Position = audioPlayerState.Position;

        if (audioPlayerState.PlaybackState == AudioPlaybackState.Playing)
            audioPlayer.Play();
    }
}