using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Collections;
using SafeMobileLib;

/*
< rsp sid="SID" id="100111" mode="MOD" HW_Type="Hw_type"
            subscriber="Phone_nr" RFID="RFID" time="TIME"
            Latitude="" Longitude="" Speed="" ai1="" ai2="" ai3="" ai4=""
            ai5="" ai6="" ai7="" ai8="" di="" ao1="" ao2="" do=""> </rsp>
 */

namespace CPlus_GW
{

    class ReceiveSMSThread
    {
        public UInt16 port;
        //public MotoTRBOGW parent;
        string gwID;
        private UdpMulticast udpMulticast;

        public ReceiveSMSThread(ushort p_port, string p_gwID)
        {
            port = p_port;
            gwID = p_gwID;

            udpMulticast = new UdpMulticast(Program.cfg.multi_IP, Program.cfg.multi_port);
            CPlusGW.TextQueue.PostItem($"Receive SMS Thread started ");
        }

        // -------------------------------------------------------------------
        // Main
        // -------------------------------------------------------------------
        public void HandleConnection()
        {
            while (true)
            {
                try
                {
                    //IPEndPoint object will allow us to read datagrams sent from any source.
                    IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);
                    SafeMobileLib.Utils.WriteLine("Starting SMS Receiving Thread on port " + port, ConsoleColor.Cyan);
                    // Blocks until a message returns on this socket from a remote host.
                    Byte[] receiveBytes = CPlusGW.smsUDPclient.Receive(ref RemoteIpEndPoint);
                    string returnData = Encoding.ASCII.GetString(receiveBytes);

                    // Uses the IPEndPoint object to determine which of these two hosts responded.
                    SafeMobileLib.Utils.WriteLine("\n--------------------");
                    SafeMobileLib.Utils.WriteLine($"SMS Received {receiveBytes.Length} bytes from {RemoteIpEndPoint.Address.ToString()}:{RemoteIpEndPoint.Port.ToString()}");
                    /*
                    SafeMobileLib.Utils.WriteLine("SMSThRecv(" + port + "): " + LocationThread.Byte2String(receiveBytes, 0, receiveBytes[1] + 2));
                    SafeMobileLib.Utils.WriteLine("From " + RemoteIpEndPoint.Address.ToString() +
                                                ":" + RemoteIpEndPoint.Port.ToString());
                                                */
                    header_T hret = DecodePacket(receiveBytes, RemoteIpEndPoint);


                    //we got ACK for message add it to DB
                    if ((hret.header == 0xBF) || (hret.header == 0x9F))
                    {
                        SafeMobileLib.Utils.WriteLine("Got ACK with header:" + hret.header + " with seq_id :" + hret.seq_no, ConsoleColor.Green);
                        lock (CPlusGW.waitConfSMSList.SyncRoot)
                        {
                            int index = -1;
                            int count = 0;
                            foreach (SMSmsg msg in CPlusGW.waitConfSMSList)
                            {
                                if (msg.seq_no == hret.seq_no)
                                {
                                    index = count;
                                    CPlusGW.confSMSQueue.PostItem(msg);

                                    string test = "#242#1#";
                                    String cmdok = "#" + msg.DBmsg_id + test;
                                    Int32 tmp = cmdok.Length + 1;
                                    tmp += tmp.ToString().Length;
                                    cmdok = "#" + tmp.ToString() + cmdok;
                                    System.Text.Encoding enc = System.Text.Encoding.ASCII;
                                    byte[] buf = enc.GetBytes(cmdok);
                                    //send SMS ack to message bus
                                    udpMulticast.Send(buf, buf.Length);
                                }
                                count++;
                            }
                            if (index > -1)//we've found the message
                                CPlusGW.waitConfSMSList.RemoveAt(index);
                        }

                    }

                }
                catch (Exception ex)
                {
                    SafeMobileLib.Utils.WriteLine("Exception in SMSThread:HandleConnection(): \r\n\tData=" +
                        ex.Data + "\r\n\tSource=" +
                        ex.Source + "\r\n\tStackTrace=" +
                        ex.StackTrace + "\r\n\tMessage=" +
                        ex.Message + "\r\n\tInnerException=" +
                        ex.InnerException, ConsoleColor.Red);
                }

            } // end while
        }

        // -------------------------------------------------------------------
        // Aux functions
        // -------------------------------------------------------------------

        struct header_T
        {
            public string address;
            public bool ext, ext2, ack, cntl;
            public byte pdu_type;
            public byte seq_no;
            public byte encoding;
            public byte header;            
        }

        header_T DecodePacket(Byte[] data, IPEndPoint RemoteIpEndPoint)
        {
            header_T hret = new header_T();
            int i, j, pdata;          
            //Console.WriteLine("--------------------");            

            pdata = (int)data[0];
            pdata <<= 8;
            pdata |= (int)data[1];

            // parse header
            int header = data[2];
            hret.header = data[2];
            //Console.WriteLine("Header: " + header.ToString("X"));
            if ((header & 0x80) != 0)
                hret.ext = true;
            else hret.ext = false;

            if ((header & 0x40) != 0)
            {
                hret.ack = true;
            }
            else hret.ack = false;

            if ((header & 0x10) != 0)
                hret.cntl = true;
            else hret.cntl = false; // txt message

            hret.pdu_type = (byte)(header & 0x0f);

            // parse address
            int addrsize = data[3];
            i = 4;
            //remove second byte of encoding( ex: "1" is ecncoded 0x31 0x00)
            string adrs = "";
            for (int ind = i; ind < addrsize + 2; ind += 2)
            {
                adrs += Encoding.UTF8.GetString(new byte[] { data[ind] });
            }
            hret.address = adrs;

            //SafeMobileLib.Utils.WriteLine("Address: " + adrs);
            for (j = 0; j < addrsize; j++)
            {
                //Console.Write(data[i + j].ToString("X"));
            }
            i += j;
            string suid = hret.address.Split('.')[0];

            // parse rest of headers
            if (hret.ext)
            {
                byte h2 = data[i];
                if ((h2 & 0x80) != 0)
                    hret.ext2 = true;
                else hret.ext2 = false;

                hret.seq_no = (byte)(h2 & 0x1F);
                i++;

                if (hret.ext2)
                { // parse third header
                    byte seqNr_MSB = (byte)(data[i] & 0x60);
                    hret.seq_no += seqNr_MSB;
                    hret.encoding = (byte)(data[i] & 0x0f);
                    i++;
                }
            }

            if (hret.ack)
            {
                Thread.Sleep(500);
                // The client needs an ACK
                //string addrs = "10000.4@tserv<mailto:" + suid + ".1>";
                string addrs = "10000.4<mailto:" + suid + ".1>";
                int addrs_len = addrs.Length;
                // The client needs an ACK
                byte extension_header = 0;
                if (hret.seq_no > 0x1F)
                    extension_header = 1;
                Byte[] sendBytes = new Byte[5 + addrs_len * 2 + extension_header];
                sendBytes[0] = 0x00; // len (2B)
                sendBytes[1] = (byte)(3 + addrs_len * 2 + extension_header);
                sendBytes[2] = 0xBF; // first header (req)                    

                sendBytes[3] = (byte)(addrs_len * 2); // addr size
                for (int indx = 0; indx < addrs_len; indx++)
                {
                    sendBytes[4 + indx * 2] = (byte)addrs[indx];
                    sendBytes[4 + indx * 2 + 1] = 0;
                }

                sendBytes[4 + addrs_len * 2] = (byte)(hret.seq_no & 0x1F); // 2nd header (opt)
                if (extension_header == 1)
                {
                    sendBytes[4 + addrs_len * 2] += 0x80; //added the extension header info
                    sendBytes[4 + addrs_len * 2 + 1] = (byte)(hret.seq_no & 0x60);
                }
                SafeMobileLib.Utils.WriteLine("»»» SMSReceiveThread ACK sent address: " + addrs + "seq_id: " + hret.seq_no, ConsoleColor.White);

                //MotoTRBOGW.smsUDPclient.Send(sendBytes, sendBytes[1] + 2, new IPEndPoint(IPAddress.Parse(MotoTRBOGW.cfg.ctrlIP), Convert.ToInt32(MotoTRBOGW.cfg.smsPort)));

                UdpClient uc = new UdpClient();
                uc.Send(sendBytes, sendBytes[1] + 2, new IPEndPoint(IPAddress.Parse(Program.cfg.ctrlIP), Convert.ToInt32(Program.cfg.smsPort)));
                CPlusGW.smsUDPclient.Send(sendBytes, sendBytes[1] + 2, RemoteIpEndPoint);
                SafeMobileLib.Utils.WriteLine($"»»» SMS ACK sent to {Program.cfg.ctrlIP}:{Program.cfg.smsPort}", ConsoleColor.White);              
            }

            int crc = 0;
            if ((! hret.cntl) && (hret.pdu_type==0))
            { // the rest is the txt message
                //Console.Write("SMS Message: ");
                Char[] cs = new Char[100];
                int k;
                for (j = i, k = 0; j < pdata + 2; j++)
                {
                    //Console.Write(" 0x" + data[j].ToString("X"));
                    if (data[j] != 0)
                    {
                        cs[k++] = (Char)data[j];
                        crc |= (Char)data[j];
                    }
                }
                //Console.WriteLine();

                // save message in inbox ht
                string s = new string(cs, 0, k);
                s.Replace("\r\n", "");
                s = s.Replace(System.Environment.NewLine, string.Empty);

                SafeMobileLib.Utils.WriteLine("Message [" + s + "]" + " from unit " + suid, ConsoleColor.Green);

                if (s.StartsWith("Rfid"))
                {
                    string rfid_string = new string(cs, 4, s.Length - 4);
                    Console.WriteLine("RFID detected:" + rfid_string);
                    OC4Jrfid rfid = new OC4Jrfid();
                    rfid.suid = suid;
                    rfid.rfid = rfid_string;
                    //MotoTRBOGW.DBQueueRFID.PostItem(rfid);
                }
                else
                {
                    CPlusGW.TextQueue.PostItem("SMS received from unit:" + suid );
                    //send SMS
                    string seqID = "1." + GetSecondsLocalFromDT(DateTime.Now).ToString() + DateTime.Now.Millisecond.ToString();
                    string test = "#132#" + suid + "#" + s + "#hyt#";
                    String cmdok = "#" + seqID + test; Int32 tmp = cmdok.Length + 1; tmp += tmp.ToString().Length; cmdok = "#" + tmp.ToString() + cmdok;
                    System.Text.Encoding enc = System.Text.Encoding.ASCII;
                    byte[] buf = enc.GetBytes(cmdok);
                    //send to messagebus
                    udpMulticast.Send(buf, buf.Length);
                }
            }
            //Console.WriteLine("i=" + i);
            SafeMobileLib.Utils.WriteLine("--------------------");

            return hret;
        }
        
        public static Int32 GetSecondsLocalFromDT(DateTime param)
        {
            System.DateTime datetime = param;
            long nOfSeconds;
            System.DateTime dt70 = new DateTime(1970, 1, 1, 0, 0, 0, 0);
            System.DateTime dttmp1 = new DateTime(1970, 1, 1, 0, 0, 0, 0);
            System.DateTime dttmp2;
            dttmp2 = dttmp1.ToLocalTime();
            TimeSpan span2 = dttmp2 - dttmp1;
            TimeSpan span = datetime - dt70;
            //nOfSeconds = (long)span.TotalSeconds - (long)span2.TotalSeconds -3600; //mai scot o ora - 3600
            if (System.TimeZone.CurrentTimeZone.IsDaylightSavingTime(param)) nOfSeconds = (long)span.TotalSeconds - (long)span2.TotalSeconds - 3600; //mai scot o ora - 3600
            else nOfSeconds = (long)span.TotalSeconds - (long)span2.TotalSeconds;
            return ((Int32)nOfSeconds);
        }

        
    }
}