using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Net.WebSockets;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Web;
using System.Web.Http;
using System.Web.WebSockets;
using VueWebApi.Tools;

namespace VueWebApi.Controllers
{
    [RoutePrefix(prefix: "Send")]
    [ControllerGroup("消息提醒", "在线接口")]
    public class SendController : ApiController
    {
        private readonly ClientWebSocket webSocket = new ClientWebSocket();
        private readonly CancellationToken _cancellation = new CancellationToken();

        /// <summary>
        /// 登录用户建立WebSocket服务连接
        /// </summary>
        /// <param name="clientName">登录用户信息</param>
        /// <returns></returns>
        [HttpGet]
        public HttpResponseMessage GetConnect(string clientName)
        {
            HttpContext.Current.AcceptWebSocketRequest(ProcessRequest); //在服务器端接受Web Socket请求，传入的函数作为Web Socket的处理函数，待Web Socket建立后该函数会被调用，在该函数中可以对Web Socket进行消息收发

            return Request.CreateResponse(HttpStatusCode.SwitchingProtocols); //构造同意切换至Web Socket的Response.
        }
        ///记录客户端
        private static List<WebSocket> _sockets = new List<WebSocket>();
        ///接受信息和发送信息
        public async Task ProcessRequest(AspNetWebSocketContext context)
        {
            try
            {
                var socket = context.WebSocket;//传入的context中有当前的web socket对象
                _sockets.Add(socket);//此处将web socket对象加入一个静态列表中

                //进入一个无限循环，当web socket close是循环结束
                while (true)
                {
                    var buffer = new ArraySegment<byte>(new byte[1024]);
                    var receivedResult = await socket.ReceiveAsync(buffer, CancellationToken.None);//对web socket进行异步接收数据
                    if (receivedResult.MessageType == WebSocketMessageType.Close)
                    {
                        await socket.CloseAsync(WebSocketCloseStatus.Empty, string.Empty, CancellationToken.None);//如果client发起close请求，对client进行ack
                        _sockets.Remove(socket);
                        break;
                    }

                    if (socket.State == System.Net.WebSockets.WebSocketState.Open)
                    {
                        string recvMsg = Encoding.UTF8.GetString(buffer.Array, 0, receivedResult.Count);
                        var recvBytes = Encoding.UTF8.GetBytes(recvMsg);
                        var sendBuffer = new ArraySegment<byte>(recvBytes);
                        foreach (var innerSocket in _sockets)//当接收到文本消息时，对当前服务器上所有web socket连接进行广播
                        {
                            if (innerSocket != socket)
                            {
                                await innerSocket.SendAsync(sendBuffer, WebSocketMessageType.Text, true, CancellationToken.None);
                            }
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }


        //客户端发送消息
        private async void SendMsg(object data)
        {
            try
            {
                await webSocket.ConnectAsync(new Uri("wss://121.196.36.24:8001/api/Send?clientName=" + 123), _cancellation);
                var sendBytes = ObjectToBytes(data);//发送的数据
                var bsend = new ArraySegment<byte>(sendBytes);
                await webSocket.SendAsync(bsend, WebSocketMessageType.Binary, true, _cancellation);
                await webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, "1", _cancellation);
                webSocket.Dispose();//记得一定要释放不然服务端还产生很多连接
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }
        public static byte[] ObjectToBytes(object obj)
        {
            using (MemoryStream ms = new MemoryStream())
            {
                IFormatter formatter = new BinaryFormatter();
                formatter.Serialize(ms, obj);
                return ms.GetBuffer();
            }
        }
    }
}