tbd-station-14/Content.Server/GameObjects/Components/Instruments/InstrumentComponent.cs

using Content.Server.GameObjects.EntitySystems;
using Content.Shared.GameObjects.Components.Instruments;
using Robust.Server.GameObjects;
using Robust.Server.GameObjects.Components.UserInterface;
using Robust.Server.Interfaces.GameObjects;
using Robust.Server.Interfaces.Player;
using Robust.Shared.GameObjects;
using Robust.Shared.Interfaces.GameObjects;
using Robust.Shared.Interfaces.Network;
using Robust.Shared.Serialization;
using Robust.Shared.ViewVariables;

namespace Content.Server.GameObjects.Components.Instruments
{
    [RegisterComponent]
    [ComponentReference(typeof(IActivate))]
    public class InstrumentComponent : SharedInstrumentComponent,
        IDropped, IHandSelected, IHandDeselected, IActivate, IUse, IThrown
    {
        /// <summary>
        ///     The client channel currently playing the instrument, or null if there's none.
        /// </summary>
        private INetChannel _instrumentPlayer;
        private bool _handheld;

        [ViewVariables]
        private BoundUserInterface _userInterface;

        /// <summary>
        ///     Whether the instrument is an item which can be held or not.
        /// </summary>
        [ViewVariables]
        public bool Handheld => _handheld;

        public override void Initialize()
        {
            base.Initialize();
            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>().GetBoundUserInterface(InstrumentUiKey.Key);
            _userInterface.OnClosed += UserInterfaceOnClosed;
        }

        public override void ExposeData(ObjectSerializer serializer)
        {
            base.ExposeData(serializer);
            serializer.DataField(ref _handheld, "handheld", false);
        }

        public override void HandleMessage(ComponentMessage message, INetChannel netChannel = null, IComponent component = null)
        {
            base.HandleMessage(message, netChannel, component);
            // If the client that sent the message isn't the client playing this instrument, we ignore it.
            if (netChannel != _instrumentPlayer) return;
            switch (message)
            {
                case InstrumentMidiEventMessage midiEventMsg:
                    SendNetworkMessage(midiEventMsg);
                    break;
            }
        }

        public void Dropped(DroppedEventArgs eventArgs)
        {
            SendNetworkMessage(new InstrumentStopMidiMessage());
            _instrumentPlayer = null;
            _userInterface.CloseAll();
        }

        public void Thrown(ThrownEventArgs eventArgs)
        {
            SendNetworkMessage(new InstrumentStopMidiMessage());
            _instrumentPlayer = null;
            _userInterface.CloseAll();
        }

        public void HandSelected(HandSelectedEventArgs eventArgs)
        {
            var session = eventArgs.User?.GetComponent<BasicActorComponent>()?.playerSession;

            if (session == null) return;

            _instrumentPlayer = session.ConnectedClient;
        }

        public void HandDeselected(HandDeselectedEventArgs eventArgs)
        {
            SendNetworkMessage(new InstrumentStopMidiMessage());
            _userInterface.CloseAll();
        }

        public void Activate(ActivateEventArgs eventArgs)
        {
            if (Handheld || !eventArgs.User.TryGetComponent(out IActorComponent actor))
                return;

            if (_instrumentPlayer != null)
                return;

            _instrumentPlayer = actor.playerSession.ConnectedClient;
            OpenUserInterface(actor.playerSession);
        }

        public bool UseEntity(UseEntityEventArgs eventArgs)
        {
            if (!eventArgs.User.TryGetComponent(out IActorComponent actor))
                return false;

            if(_instrumentPlayer == actor.playerSession.ConnectedClient)
                OpenUserInterface(actor.playerSession);
            return false;
        }

        private void UserInterfaceOnClosed(ServerBoundUserInterfaceMessage obj)
        {
            if (!Handheld && obj.Session.ConnectedClient == _instrumentPlayer)
            {
                _instrumentPlayer = null;
                SendNetworkMessage(new InstrumentStopMidiMessage());
            }
        }

        private void OpenUserInterface(IPlayerSession session)
        {
            _userInterface.Open(session);
        }
    }
}