using System.Collections.Generic;
using System.Linq;
using JetBrains.Annotations;
using Robust.Shared.Audio;
using Robust.Shared.GameObjects;
using Robust.Shared.Map;
using Robust.Shared.Player;
using Robust.Shared.Players;

namespace Robust.Server.GameObjects;
[UsedImplicitly]
public sealed class AudioSystem : SharedAudioSystem
{
    private uint _streamIndex;

    private sealed class AudioSourceServer : IPlayingAudioStream
    {
        private readonly uint _id;
        private readonly AudioSystem _audioSystem;
        private readonly IEnumerable<ICommonSession>? _sessions;

        internal AudioSourceServer(AudioSystem parent, uint identifier, IEnumerable<ICommonSession>? sessions = null)
        {
            _audioSystem = parent;
            _id = identifier;
            _sessions = sessions;
        }
        public void Stop()
        {
            _audioSystem.InternalStop(_id, _sessions);
        }
    }

    private void InternalStop(uint id, IEnumerable<ICommonSession>? sessions = null)
    {
        var msg = new StopAudioMessageClient
        {
            Identifier = id
        };

        if (sessions == null)
            RaiseNetworkEvent(msg);
        else
        {
            foreach (var session in sessions)
            {
                RaiseNetworkEvent(msg, session.ConnectedClient);
            }
        }
    }

    private uint CacheIdentifier()
    {
        return unchecked(_streamIndex++);
    }

    /// <inheritdoc />
    public override IPlayingAudioStream? PlayGlobal(string filename, Filter playerFilter, AudioParams? audioParams = null)
    {
        var id = CacheIdentifier();
        var msg = new PlayAudioGlobalMessage
        {
            FileName = filename,
            AudioParams = audioParams ?? AudioParams.Default,
            Identifier = id
        };

        RaiseNetworkEvent(msg, playerFilter);

        return new AudioSourceServer(this, id, playerFilter.Recipients.ToArray());
    }

    public override IPlayingAudioStream? Play(string filename, Filter playerFilter, EntityUid uid, AudioParams? audioParams = null)
    {
        if(!EntityManager.TryGetComponent<TransformComponent>(uid, out var transform))
            return null;

        var id = CacheIdentifier();

        var fallbackCoordinates = GetFallbackCoordinates(transform.MapPosition);

        var msg = new PlayAudioEntityMessage
        {
            FileName = filename,
            Coordinates = transform.Coordinates,
            FallbackCoordinates = fallbackCoordinates,
            EntityUid = uid,
            AudioParams = audioParams ?? AudioParams.Default,
            Identifier = id,
        };

        RaiseNetworkEvent(msg, playerFilter);

        return new AudioSourceServer(this, id, playerFilter.Recipients.ToArray());
    }

    /// <inheritdoc />
    public override IPlayingAudioStream? Play(string filename, Filter playerFilter, EntityCoordinates coordinates, AudioParams? audioParams = null)
    {
        var id = CacheIdentifier();

        var fallbackCoordinates = GetFallbackCoordinates(coordinates.ToMap(EntityManager));

        var msg = new PlayAudioPositionalMessage
        {
            FileName = filename,
            Coordinates = coordinates,
            FallbackCoordinates = fallbackCoordinates,
            AudioParams = audioParams ?? AudioParams.Default,
            Identifier = id
        };

        RaiseNetworkEvent(msg, playerFilter);

        return new AudioSourceServer(this, id, playerFilter.Recipients.ToArray());
    }

    /// <inheritdoc />
    public override IPlayingAudioStream? PlayPredicted(SoundSpecifier? sound, EntityUid source, EntityUid? user, AudioParams? audioParams = null)
    {
        if (sound == null)
            return null;

        var filter = Filter.Pvs(source, entityManager: EntityManager, playerManager: PlayerManager, cfgManager: CfgManager).RemoveWhereAttachedEntity(e => e == user);
        return Play(sound, filter, source, audioParams);
    }
}