using EVCB_OCPP.Domain;
using EVCB_OCPP.WSServer;
using EVCB_OCPP.WSServer.Helper;
using NLog;
using OCPPPackage.Profiles;
using SuperWebSocket;
using SuperWebSocket.SubProtocol;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
using System.Text;

namespace OCPPServer.Protocol
{
    public class OCPPWSServer : WebSocketServer<ClientData>
    {

        static private ILogger logger = NLog.LogManager.GetCurrentClassLogger();
        /// <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 ValidateClientCertificate(ClientData session, object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
        {
            //  Console.WriteLine(string.Format("{0} :{1}", session.ChargeBoxId + " ValidateClientCertificate", sslPolicyErrors));
            return true;
            // return base.ValidateClientCertificate(session, sender, certificate, chain, sslPolicyErrors);
        }

        protected override bool ValidateHandshake(ClientData session, string origin)
        {
            int securityProfile = GlobalConfig.SecurityProfileLevel;
            string authorizationKey = GlobalConfig.SecurityPassword;
            bool authorizated = false;

            session.ISOCPP20 = session.SecWebSocketProtocol.ToLower().Contains("ocpp2.0");


            if (string.IsNullOrEmpty(session.Path))
            {
                logger.Warn("===========================================");
                logger.Warn("session.Path EMPTY");
                logger.Warn("===========================================");
            }

            string[] words = session.Path.Split('/');
            session.ChargeBoxId = words.Last();

            if (ConfigurationManager.AppSettings["MaintainMode"] == "1")
            {
                session.ChargeBoxId = session.ChargeBoxId + "_2";
            }

            logger.Info(string.Format("ValidateHandshake: {0}", session.Path));

            if (session.ISOCPP20)
            {
                // 1.6 server only support change server  function
                securityProfile = 0;
            }

            switch (securityProfile)
            {
                case 0:
                    {
                        authorizated = true;
                    }
                    break;
                case 1:
                    {
                        if(session.UriScheme == "ws")
                        {
                            string client_authorization = string.Empty;
                            if (session.Items.ContainsKey("Authorization") || session.Items.ContainsKey("authorization"))
                            {
                                client_authorization = session.Items.ContainsKey("Authorization") ? session.Items["Authorization"].ToString().Replace("Basic ", "") : session.Items["authorization"].ToString().Replace("Basic ", "");
                            }
                            if (ValidateSecurity(session.ChargeBoxId, authorizationKey, client_authorization))
                            {
                                authorizated = true;
                            }
                            else
                            {
                                logger.Warn(string.Format(" {0} ValidateSecurity Fail client_authorization:[{1}]:", session.ChargeBoxId, client_authorization));
                            }
                        }
                      
                    }
                    break;
                case 2:
                    {
                        if (session.UriScheme == "wss")
                        {
                            string client_authorization = string.Empty;
                            if (session.Items.ContainsKey("Authorization") || session.Items.ContainsKey("authorization"))
                            {
                                client_authorization = session.Items.ContainsKey("Authorization") ? session.Items["Authorization"].ToString().Replace("Basic ", "") : session.Items["authorization"].ToString().Replace("Basic ", "");
                            }
                            if (ValidateSecurity(session.ChargeBoxId, authorizationKey, client_authorization))
                            {
                                authorizated = true;
                            }
                            else
                            {
                                logger.Warn(string.Format(" {0} ValidateSecurity Fail client_authorization:[{1}]:", session.ChargeBoxId, client_authorization));
                            }
                        }
                    }
                    break;
                case 3:
                    {
                        authorizated = false;
                    }
                    break;
                default:
                    break;
            }       
           
            if(!authorizated)
            {
                StringBuilder responseBuilder = new StringBuilder();

                responseBuilder.AppendFormatWithCrCf(@"HTTP/{0} {1} {2}", "1.1",
                (int)HttpStatusCode.Unauthorized, @"Unauthorized");

                responseBuilder.AppendWithCrCf();
                string sb = responseBuilder.ToString();
                byte[] data = Encoding.UTF8.GetBytes(sb);

                ((IWebSocketSession)session).SendRawData(data, 0, data.Length);
                logger.Info(sb);
                return false;
            }
           

            return true;
        }



        private bool ValidateSecurity(string chargeBoxId, string authorizationKey, string client_authorization)
        {
            bool result = false;
            if (string.IsNullOrEmpty(client_authorization)) return result;

            string server_authorization = EncodeHelper.EncodeBase64(string.Format("{0}:{1}", chargeBoxId, authorizationKey));
            if (client_authorization == server_authorization)
            {
                result =  true;
            }
            return result;
        }
    }
}