using Evcb.Domain.Model;
using Evcb.Repository;
using Evcb.Service;
using SuperSocket.Common;
using SuperWebSocket;
using SuperWebSocket.SubProtocol;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace OCPPServer.Protocol
{
    public class OCPPWSServer : WebSocketServer<ClientData>
    {
        /// <summary>
        /// 可允許連線Clinet數
        /// </summary>
        public int connectNum { get; set; }

        /// <summary>
        /// 是否限制連線Clinet數
        /// </summary>
        public bool beConnectLimit { get; set; }

        /// <summary>
        /// Initializes a new instance of the <see cref="WebSocketServer"/> class.
        /// </summary>
        /// <param name="subProtocols">The sub protocols.</param>
        public OCPPWSServer(IEnumerable<ISubProtocol<ClientData>> subProtocols)
            : base(subProtocols)
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="WebSocketServer"/> class.
        /// </summary>
        /// <param name="subProtocol">The sub protocol.</param>
        public OCPPWSServer(ISubProtocol<ClientData> subProtocol)
            : base(subProtocol)
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="WebSocketServer"/> class.
        /// </summary>
        public OCPPWSServer()
            : base(new List<ISubProtocol<ClientData>>())
        {
        }

        protected override bool ValidateHandshake(ClientData session, string origin)
        {
            //初始化ClientData
            session.InitialPileData();
            //確認電樁所送的電樁識別碼是否包含在request path中
            string[] words = session.Path.Split('/');
            using (var db = new PhihongDbContext())
            {
                if (this.beConnectLimit == true)
                {
                    var connectPile = db.Machine.Where(c => c.Online == true).ToList();
                    if (connectPile.Count >= this.connectNum)
                    {
                        byte[] m_SwitchResponse;
                        var responseBuilder = new StringBuilder();
                        responseBuilder.AppendWithCrCf("HTTP/1.1 403"); //403 Forbidden : 用戶端並無訪問權限，所以伺服器給予應有的回應。
                        responseBuilder.AppendWithCrCf("Upgrade: WebSocket");
                        responseBuilder.AppendWithCrCf("Connection: Upgrade");
                        responseBuilder.AppendWithCrCf("Sec-WebSocket-Version: " + session.SecWebSocketVersion);
                        responseBuilder.AppendWithCrCf();

                        m_SwitchResponse = Encoding.UTF8.GetBytes(responseBuilder.ToString());

                        session.SendRawData(m_SwitchResponse, 0, m_SwitchResponse.Length);
                        return false;
                    }
                }

                IUnitOfWork uow = new UnitOfWork(db);
                IMachineService machineSrv = new MachineService(uow);
                var machine = machineSrv.GetByCustomId(words.Last());
                if (machine == null)
                {
                    byte[] m_SwitchResponse;
                    var responseBuilder = new StringBuilder();
                    responseBuilder.AppendWithCrCf("HTTP/1.1 404");
                    responseBuilder.AppendWithCrCf("Upgrade: WebSocket");
                    responseBuilder.AppendWithCrCf("Connection: Upgrade");
                    responseBuilder.AppendWithCrCf("Sec-WebSocket-Version: " + session.SecWebSocketVersion);
                    responseBuilder.AppendWithCrCf();

                    m_SwitchResponse = Encoding.UTF8.GetBytes(responseBuilder.ToString());

                    session.SendRawData(m_SwitchResponse, 0, m_SwitchResponse.Length);
                    return false;

                    //session.CloseWithHandshake(session.ProtocolProcessor.CloseStatusClode.NormalClosure, "This machine can't be  recognized.");
                }
                session.MachineCustomIdTemp = words.Last();
                uow.Dispose();
            }

            //session.MachineCustomIdTemp = "RDTEST101";

            //確認電樁連線所送的SubProtocol是否被Server支援
            if (session.SecWebSocketProtocol.ToLower() != "ocpp1.6")
            {
                const string m_Magic = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
                const string SecWebSocketKey = "Sec-WebSocket-Key";
                const string ResponseHeadLine10 = "HTTP/1.1 101 Switching Protocols";
                const string Upgrade = "Upgrade";
                const string ResponseUpgradeLine = Upgrade + ": WebSocket";
                const string Connection = "Connection";
                const string ResponseConnectionLine = Connection + ": Upgrade";
                const string ResponseAcceptLine = "Sec-WebSocket-Accept: {0}";

                var responseBuilder = new StringBuilder();
                var secWebSocketKey = session.Items.GetValue<string>(SecWebSocketKey, string.Empty);
                if (string.IsNullOrEmpty(secWebSocketKey))
                {
                    return false;
                }
                string secKeyAccept = string.Empty;

                try
                {
                    secKeyAccept = Convert.ToBase64String(System.Security.Cryptography.SHA1.Create().ComputeHash(Encoding.ASCII.GetBytes(secWebSocketKey + m_Magic)));
                }
                catch (Exception)
                {
                    return false;
                }

                responseBuilder.AppendWithCrCf(ResponseHeadLine10);
                responseBuilder.AppendWithCrCf(ResponseUpgradeLine);
                responseBuilder.AppendWithCrCf(ResponseConnectionLine);
                responseBuilder.AppendFormatWithCrCf(ResponseAcceptLine, secKeyAccept);
                responseBuilder.AppendWithCrCf();
                byte[] data = Encoding.UTF8.GetBytes(responseBuilder.ToString());
                session.SendRawData(data, 0, data.Length);
                session.CloseWithHandshake(session.ProtocolProcessor.CloseStatusClode.NormalClosure, "This SubProtocol can't be  supported.");
                return false;
            }
            //session.m_ReceiveData += new ClientData.OCPPClientDataEventHandler<ClientData, String>(WSServer.ReceivedMessage);
            return true;
        }
    }
}