WingRtcService/VRTC/VRTC.WpfClient/PeerConnectionManager.cs

using System;
using System.Collections.Concurrent;
using System.Linq;
using System.Text.Json;

namespace VRTC.WpfClient
{
    public interface IPeerConnectionManager
    {
        /// <summary>
        /// Join room
        /// </summary>
        /// <param name="roomId">The room id you want to join</param>
        /// <param name="localClientId">The local client id who join the room</param>
        void Join(uint roomId, string localClientId);

        /// <summary>
        /// Get a peer connection according to client id
        /// </summary>
        /// <param name="remoteClientId">The remote client id</param>
        /// <returns></returns>
        PeerConnetion GetPeerConnetion(string remoteClientId);

        /// <summary>
        /// Close all connection
        /// </summary>
        void Close();

        /// <summary>
        /// Implement answer after receiving offer
        /// </summary>
        /// <param name="clientId">The remove client id</param>
        /// <param name="sdp">The remote sdp</param>
        void Answer(string clientId, string sdp);
        void SetRemoteDesc(string remoteClientId, string sdp);
        void AddIceCandidate(string remoteClientId, string sdpMid, int sdpMLineIndex, string candidate);
        void Offer(string remoteClientId);
    }
    public class PeerConnectionManager : IPeerConnectionManager
    {
        private ConcurrentDictionary<string, PeerConnetion> _peerConnections = new ConcurrentDictionary<string,PeerConnetion>();
        private uint _roomId;
        private string _localClientId;
        private readonly Action<string> _sendMessageToSever;
        private readonly Action<VideoFrameData> onLocalFrameArrived;
        private readonly Action<VideoFrameData> onRemoteFrameArrived;
        private readonly string _vidoeDevice;

        public PeerConnectionManager(Action<string> sendMessageToSever, Action<VideoFrameData> onLocalFrameArrived, Action<VideoFrameData> onRemoteFrameArrived, string vidoeDevice)
        {
            this._sendMessageToSever = sendMessageToSever;
            this.onLocalFrameArrived = onLocalFrameArrived;
            this.onRemoteFrameArrived = onRemoteFrameArrived;
            this._vidoeDevice = vidoeDevice;
        }

        /// <summary>
        /// Join room
        /// </summary>
        /// <param name="roomId">The room id you want to join</param>
        /// <param name="localClientId">The local client id who join the room</param>
        public void Join(uint roomId, string localClientId)
        {
            _roomId = roomId;
            _localClientId = localClientId;
            var jsonMsg = new VrtcClientMessage();
            jsonMsg.Command = VrtcCommands.Join;            
            jsonMsg.RoomId = _roomId;
            jsonMsg.ClientId = _localClientId;
            var msg = jsonMsg.ToJson();
            _sendMessageToSever(msg);           
        }

        public void Offer(string remoteClientId)
        {
            var connection = GetPeerConnetion(remoteClientId);
            if (connection != null)
            {
                connection.Offer();
            }
        }
        
        /// <summary>
        /// Get a peer connection according to client id
        /// </summary>
        /// <param name="clientId">The remote client id</param>
        /// <returns></returns>
        public PeerConnetion GetPeerConnetion(string clientId)
        {            
            var conn = _peerConnections.GetOrAdd(clientId, (id) => {
                Logger.WriteLineInfo($"add new client {clientId}");
                var connection = new PeerConnetion(_roomId, _localClientId, clientId, _sendMessageToSever, onLocalFrameArrived, onRemoteFrameArrived, _vidoeDevice);
                                
                return connection;
            });  

            return conn;
        }

        /// <summary>
        /// Close all connection
        /// </summary>
        public void Close()
        {
            var connections = _peerConnections.Values.ToList();
            foreach (var connection in connections)
            {
                connection.Close();
            }
        }

        /// <summary>
        /// Implement answer after receiving offer
        /// </summary>
        /// <param name="remoteClientId">The remove client id</param>
        /// <param name="sdp">The remote sdp</param>
        public void Answer(string remoteClientId, string sdp)
        {
            var connection = GetPeerConnetion(remoteClientId);
            if (connection != null)
            {
                connection.Answer(sdp);
            }
        }

        public void SetRemoteDesc(string remoteClientId, string sdp)
        {
            var connection = GetPeerConnetion(remoteClientId);
            if (connection != null)
            {
                connection.OnOfferReply(sdp);
            }
        }

        public void AddIceCandidate(string remoteClientId, string sdpMid, int sdpMLineIndex, string candidate)
        {
            var connection = GetPeerConnetion(remoteClientId);
            if (connection != null)
            {
                connection.AddIceCandidate(sdpMid, sdpMLineIndex, candidate);
            }
        }
    }
}