//
//  cdmrmmdvmprotocol.cpp
//  xlxd
//
//  Created by Jean-Luc Deltombe (LX3JL) on 104/03/2017.
//  Copyright © 2015 Jean-Luc Deltombe (LX3JL). All rights reserved.
//
// ----------------------------------------------------------------------------
//    This file is part of xlxd.
//
//    xlxd is free software: you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation, either version 3 of the License, or
//    (at your option) any later version.
//
//    xlxd is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU General Public License for more details.
//
//    You should have received a copy of the GNU General Public License
//    along with Foobar.  If not, see <http://www.gnu.org/licenses/>.
// ----------------------------------------------------------------------------

#include "main.h"
#include <string.h>
#include "cdmrmmdvmclient.h"
#include "cdmrmmdvmprotocol.h"
#include "creflector.h"
#include "cgatekeeper.h"
#include "cbptc19696.h"
#include "crs129.h"
#include "cgolay2087.h"
#include "cqr1676.h"


////////////////////////////////////////////////////////////////////////////////////////
// define

#define CMD_NONE        0
#define CMD_LINK        1
#define CMD_UNLINK      2

////////////////////////////////////////////////////////////////////////////////////////
// constants

static uint8 g_DmrSyncBSVoice[]    = { 0x07,0x55,0xFD,0x7D,0xF7,0x5F,0x70 };
static uint8 g_DmrSyncBSData[]     = { 0x0D,0xFF,0x57,0xD7,0x5D,0xF5,0xD0 };
static uint8 g_DmrSyncMSVoice[]    = { 0x07,0xF7,0xD5,0xDD,0x57,0xDF,0xD0 };
static uint8 g_DmrSyncMSData[]     = { 0x0D,0x5D,0x7F,0x77,0xFD,0x75,0x70 };


////////////////////////////////////////////////////////////////////////////////////////
// operation

bool CDmrmmdvmProtocol::Init(void)
{
    bool ok;
    
    // base class
    ok = CProtocol::Init();
    
    // update the reflector callsign
    //m_ReflectorCallsign.PatchCallsign(0, (const uint8 *)"DMR", 3);
    
    // create our socket
    ok &= m_Socket.Open(DMRMMDVM_PORT);
    
    // update time
    m_LastKeepaliveTime.Now();
    
    // random number generator
    time_t t;
    ::srand((unsigned) time(&t));
    m_uiAuthSeed = (uint32)rand();
    
    // done
    return ok;
}



////////////////////////////////////////////////////////////////////////////////////////
// task

void CDmrmmdvmProtocol::Task(void)
{
    CBuffer             Buffer;
    CIp                 Ip;
    CCallsign           Callsign;
    int                 iRssi;
    uint8               Cmd;
    uint8               CallType;
    CDvHeaderPacket     *Header;
    CDvFramePacket      *Frames[3];
    CDvLastFramePacket  *LastFrame;
    
    // handle incoming packets
    if ( m_Socket.Receive(&Buffer, &Ip, 20) != -1 )
    {
        //Buffer.DebugDump(g_Reflector.m_DebugFile);
        // crack the packet
        if ( IsValidDvFramePacket(Buffer, Frames) )
        {
            //std::cout << "DMRmmdvm DV frame" << std::endl;
            
            for ( int i = 0; i < 3; i++ )
            {
                OnDvFramePacketIn(Frames[i], &Ip);
            }
        }
        else if ( IsValidDvHeaderPacket(Buffer, &Header, &Cmd, &CallType) )
        {
            //std::cout << "DMRmmdvm DV header:"  << std::endl <<  *Header << std::endl;
            //std::cout << "DMRmmdvm DV header"  << std::endl;
            
            // callsign muted?
            if ( g_GateKeeper.MayTransmit(Header->GetMyCallsign(), Ip, PROTOCOL_DMRMMDVM) )
            {
                // handle it
                OnDvHeaderPacketIn(Header, Ip, Cmd, CallType);
            }
            else
            {
                delete Header;
            }
        }
        else if ( IsValidDvLastFramePacket(Buffer, &LastFrame) )
        {
            //std::cout << "DMRmmdvm DV last frame"  << std::endl;
            
            OnDvLastFramePacketIn(LastFrame, &Ip);
        }
        else if ( IsValidConnectPacket(Buffer, &Callsign, Ip) )
        {
            std::cout << "DMRmmdvm connect packet from " << Callsign << " at " << Ip << std::endl;
            
            // callsign authorized?
            if ( g_GateKeeper.MayLink(Callsign, Ip, PROTOCOL_DMRMMDVM) )
            {
                // acknowledge the request
                EncodeConnectAckPacket(&Buffer, Callsign, m_uiAuthSeed);
                m_Socket.Send(Buffer, Ip);
            }
            else
            {
                // deny the request
                EncodeNackPacket(&Buffer, Callsign);
                m_Socket.Send(Buffer, Ip);
            }
            
        }
        else if ( IsValidAuthenticationPacket(Buffer, &Callsign, Ip) )
        {
            std::cout << "DMRmmdvm authentication packet from " << Callsign << " at " << Ip << std::endl;
            
            // callsign authorized?
            if ( g_GateKeeper.MayLink(Callsign, Ip, PROTOCOL_DMRMMDVM) )
            {
                // acknowledge the request
                EncodeAckPacket(&Buffer, Callsign);
                m_Socket.Send(Buffer, Ip);
                
                // add client if needed
                CClients *clients = g_Reflector.GetClients();
                CClient *client = clients->FindClient(Callsign, Ip, PROTOCOL_DMRMMDVM);
                // client already connected ?
                if ( client == NULL )
                {
                    std::cout << "DMRmmdvm login from " << Callsign << " at " << Ip << std::endl;
                    
                    // create the client
                    CDmrmmdvmClient *newclient = new CDmrmmdvmClient(Callsign, Ip);
                    
                    // and append
                    clients->AddClient(newclient);
                }
                else
                {
                    client->Alive();
                }
                // and done
                g_Reflector.ReleaseClients();
            }
            else
            {
                // deny the request
                EncodeNackPacket(&Buffer, Callsign);
                m_Socket.Send(Buffer, Ip);
            }
            
        }
        else if ( IsValidDisconnectPacket(Buffer, &Callsign) )
        {
            std::cout << "DMRmmdvm disconnect packet from " << Callsign << " at " << Ip << std::endl;
            
            // find client & remove it
            CClients *clients = g_Reflector.GetClients();
            CClient *client = clients->FindClient(Ip, PROTOCOL_DMRMMDVM);
            if ( client != NULL )
            {
                clients->RemoveClient(client);
            }
            g_Reflector.ReleaseClients();
        }
        else if ( IsValidConfigPacket(Buffer, &Callsign, Ip) )
        {
            std::cout << "DMRmmdvm configuration packet from " << Callsign << " at " << Ip << std::endl;
            
            // acknowledge the request
            EncodeAckPacket(&Buffer, Callsign);
            m_Socket.Send(Buffer, Ip);
        }
        else if ( IsValidKeepAlivePacket(Buffer, &Callsign) )
        {
            //std::cout << "DMRmmdvm keepalive packet from " << Callsign << " at " << Ip << std::endl;
            
            // find all clients with that callsign & ip and keep them alive
            CClients *clients = g_Reflector.GetClients();
            int index = -1;
            CClient *client = NULL;
            while ( (client = clients->FindNextClient(Callsign, Ip, PROTOCOL_DMRMMDVM, &index)) != NULL )
            {
                // acknowledge
                EncodeKeepAlivePacket(&Buffer, client);
                m_Socket.Send(Buffer, Ip);
                
                // and mark as alive
                client->Alive();
            }
            g_Reflector.ReleaseClients();
        }
        else if ( IsValidRssiPacket(Buffer, &Callsign, &iRssi) )
        {
            // std::cout << "DMRmmdvm RSSI packet from " << Callsign << " at " << Ip << std::endl
            
            // ignore...
        }
        else if ( IsValidOptionPacket(Buffer, &Callsign) )
        {
            std::cout << "DMRmmdvm options packet from " << Callsign << " at " << Ip << std::endl;
            
            // acknowledge the request
            EncodeAckPacket(&Buffer, Callsign);
            m_Socket.Send(Buffer, Ip);
        }
        else if ( Buffer.size() != 55 )
        {
            std::cout << "DMRmmdvm packet (" << Buffer.size() << ")" << std::endl;
            //std::cout << Buffer << std::endl;
        }
    }
    
    // handle end of streaming timeout
    CheckStreamsTimeout();
    
    // handle queue from reflector
    HandleQueue();
    
    
    // keep client alive
    if ( m_LastKeepaliveTime.DurationSinceNow() > DMRMMDVM_KEEPALIVE_PERIOD )
    {
        //
        HandleKeepalives();
        
        // update time
        m_LastKeepaliveTime.Now();
    }
    
}

////////////////////////////////////////////////////////////////////////////////////////
// streams helpers

bool CDmrmmdvmProtocol::OnDvHeaderPacketIn(CDvHeaderPacket *Header, const CIp &Ip, uint8 cmd, uint8 CallType)
{
    bool newstream = false;
    bool lastheard = false;
    
    //
    CCallsign via(Header->GetRpt1Callsign());

    // find the stream
    CPacketStream *stream = GetStream(Header->GetStreamId());
    if ( stream == NULL )
    {
        // no stream open yet, open a new one
        // firstfind this client
        CClient *client = g_Reflector.GetClients()->FindClient(Ip, PROTOCOL_DMRMMDVM);
        if ( client != NULL )
        {
            // process cmd if any
            if ( !client->HasReflectorModule() )
            {
                // not linked yet
                if ( cmd == CMD_LINK )
                {
                    if ( g_Reflector.IsValidModule(Header->GetRpt2Module()) )
                    {
                        std::cout << "DMRmmdvm client " << client->GetCallsign() << " linking on module " << Header->GetRpt2Module() << std::endl;
                        // link
                        client->SetReflectorModule(Header->GetRpt2Module());
                   }
                    else
                    {
                        std::cout << "DMRMMDVM node " << via << " link attempt on non-existing module" << std::endl;
                    }
                }
            }
            else
            {
                // already linked
                if ( cmd == CMD_UNLINK )
                {
                    std::cout << "DMRmmdvm client " << client->GetCallsign() << " unlinking" << std::endl;
                    // unlink
                    client->SetReflectorModule(' ');
                }
                else
                {
                    // replace rpt2 module with currently linked module
                    Header->SetRpt2Module(client->GetReflectorModule());
                }
            }
            
            // and now, re-check module is valid && that it's not a private call
            if ( g_Reflector.IsValidModule(Header->GetRpt2Module()) && (CallType == DMR_GROUP_CALL) )
            {
                // yes, try to open the stream
                if ( (stream = g_Reflector.OpenStream(Header, client)) != NULL )
                {
                    // keep the handle
                    m_Streams.push_back(stream);
                    newstream = true;
                    lastheard = true;
                }
            }
        }
        else
        {
            lastheard = true;
        }
        
        // release
        g_Reflector.ReleaseClients();
        
        // update last heard
        if ( lastheard )
        {
            g_Reflector.GetUsers()->Hearing(Header->GetMyCallsign(), via, Header->GetRpt2Callsign());
            g_Reflector.ReleaseUsers();
        }
        
        // delete header if needed
        if ( !newstream )
        {
            delete Header;
        }
    }
    else
    {
        // stream already open
        // skip packet, but tickle the stream
        stream->Tickle();
        // and delete packet
        delete Header;
    }
    
    // done
    return newstream;
}

////////////////////////////////////////////////////////////////////////////////////////
// queue helper

void CDmrmmdvmProtocol::HandleQueue(void)
{
    
    m_Queue.Lock();
    while ( !m_Queue.empty() )
    {
        // get the packet
        CPacket *packet = m_Queue.front();
        m_Queue.pop();
        
        // get our sender's id
        int iModId = g_Reflector.GetModuleIndex(packet->GetModuleId());
        
        // encode
        CBuffer buffer;
        
        // check if it's header
        if ( packet->IsDvHeader() )
        {
            // update local stream cache
            // this relies on queue feeder setting valid module id
            m_StreamsCache[iModId].m_dvHeader = CDvHeaderPacket((const CDvHeaderPacket &)*packet);
            m_StreamsCache[iModId].m_uiSeqId = 0;
            
            // encode it
            EncodeDvHeaderPacket((const CDvHeaderPacket &)*packet, m_StreamsCache[iModId].m_uiSeqId, &buffer);
            m_StreamsCache[iModId].m_uiSeqId = 1;
        }
        // check if it's a last frame
        else if ( packet->IsLastPacket() )
        {
            // encode it
            EncodeDvLastPacket(m_StreamsCache[iModId].m_dvHeader, m_StreamsCache[iModId].m_uiSeqId, &buffer);
            m_StreamsCache[iModId].m_uiSeqId = (m_StreamsCache[iModId].m_uiSeqId + 1) & 0xFF;
        }
        // otherwise, just a regular DV frame
        else
        {
            // update local stream cache or send triplet when needed
            switch ( packet->GetDmrPacketSubid() )
            {
                case 1:
                    m_StreamsCache[iModId].m_dvFrame0 = CDvFramePacket((const CDvFramePacket &)*packet);
                    break;
                case 2:
                    m_StreamsCache[iModId].m_dvFrame1 = CDvFramePacket((const CDvFramePacket &)*packet);
                    break;
                case 3:
                    EncodeDvPacket(
                                   m_StreamsCache[iModId].m_dvHeader,
                                   m_StreamsCache[iModId].m_dvFrame0,
                                   m_StreamsCache[iModId].m_dvFrame1,
                                   (const CDvFramePacket &)*packet,
                                   m_StreamsCache[iModId].m_uiSeqId,
                                   &buffer);
                    m_StreamsCache[iModId].m_uiSeqId = (m_StreamsCache[iModId].m_uiSeqId + 1) & 0xFF;
                    break;
                default:
                    break;
            }
        }
        
        // send it
        if ( buffer.size() > 0 )
        {
            // and push it to all our clients linked to the module and who are not streaming in
            CClients *clients = g_Reflector.GetClients();
            int index = -1;
            CClient *client = NULL;
            while ( (client = clients->FindNextClient(PROTOCOL_DMRMMDVM, &index)) != NULL )
            {
                // is this client busy ?
                if ( !client->IsAMaster() && (client->GetReflectorModule() == packet->GetModuleId()) )
                {
                    // no, send the packet
                    m_Socket.Send(buffer, client->GetIp());
                    
                }
            }
            g_Reflector.ReleaseClients();
        }
        
        // done
        delete packet;
    }
    m_Queue.Unlock();
}

////////////////////////////////////////////////////////////////////////////////////////
// keepalive helpers

void CDmrmmdvmProtocol::HandleKeepalives(void)
{
    // DMRhomebrew protocol keepalive request is client tasks
    // here, just check that all clients are still alive
    // and disconnect them if not
    
    // iterate on clients
    CClients *clients = g_Reflector.GetClients();
    int index = -1;
    CClient *client = NULL;
    while ( (client = clients->FindNextClient(PROTOCOL_DMRMMDVM, &index)) != NULL )
    {
        // is this client busy ?
        if ( client->IsAMaster() )
        {
            // yes, just tickle it
            client->Alive();
        }
        // check it's still with us
        else if ( !client->IsAlive() )
        {
            // no, disconnect
            CBuffer disconnect;
            m_Socket.Send(disconnect, client->GetIp());
            
            // remove it
            std::cout << "DMRmmdvm client " << client->GetCallsign() << " keepalive timeout" << std::endl;
            clients->RemoveClient(client);
        }
        
    }
    g_Reflector.ReleaseClients();
}

////////////////////////////////////////////////////////////////////////////////////////
// packet decoding helpers

bool CDmrmmdvmProtocol::IsValidKeepAlivePacket(const CBuffer &Buffer, CCallsign *callsign)
{
    uint8 tag[] = { 'R','P','T','P','I','N','G' };
    
    bool valid = false;
    if ( (Buffer.size() == 11) && (Buffer.Compare(tag, sizeof(tag)) == 0) )
    {
        uint32 uiRptrId = MAKEDWORD(MAKEWORD(Buffer.data()[10],Buffer.data()[9]),MAKEWORD(Buffer.data()[8],Buffer.data()[7]));
        callsign->SetDmrid(uiRptrId, true);
        callsign->SetModule(MMDVM_MODULE_ID);
        valid = callsign->IsValid();
    }
    return valid;
}

bool CDmrmmdvmProtocol::IsValidConnectPacket(const CBuffer &Buffer, CCallsign *callsign, const CIp &Ip)
{
    uint8 tag[] = { 'R','P','T','L' };
    
    bool valid = false;
    if ( (Buffer.size() == 8) && (Buffer.Compare(tag, sizeof(tag)) == 0) )
    {
        uint32 uiRptrId = MAKEDWORD(MAKEWORD(Buffer.data()[7],Buffer.data()[6]),MAKEWORD(Buffer.data()[5],Buffer.data()[4]));
        callsign->SetDmrid(uiRptrId, true);
        callsign->SetModule(MMDVM_MODULE_ID);
        valid = callsign->IsValid();
        if ( !valid)
        {
            std::cout << "DMRmmdvm connect packet from IP address " << Ip << " / unrecognized id " << (int)callsign->GetDmrid()  << std::endl;
        }
    }
    return valid;
}

bool CDmrmmdvmProtocol::IsValidAuthenticationPacket(const CBuffer &Buffer, CCallsign *callsign, const CIp &Ip)
{
    uint8 tag[] = { 'R','P','T','K' };
    
    bool valid = false;
    if ( (Buffer.size() == 40) && (Buffer.Compare(tag, sizeof(tag)) == 0) )
    {
        uint32 uiRptrId = MAKEDWORD(MAKEWORD(Buffer.data()[7],Buffer.data()[6]),MAKEWORD(Buffer.data()[5],Buffer.data()[4]));
        callsign->SetDmrid(uiRptrId, true);
        callsign->SetModule(MMDVM_MODULE_ID);
        valid = callsign->IsValid();
        if ( !valid)
        {
            std::cout << "DMRmmdvm authnetication packet from IP address " << Ip << " / unrecognized id " << (int)callsign->GetDmrid()  << std::endl;
        }

    }
    return valid;
}

bool CDmrmmdvmProtocol::IsValidDisconnectPacket(const CBuffer &Buffer, CCallsign *callsign)
{
    uint8 tag[] = { 'R','P','T','C','L' };
    
    bool valid = false;
    if ( (Buffer.size() == 13) && (Buffer.Compare(tag, sizeof(tag)) == 0) )
    {
        uint32 uiRptrId = MAKEDWORD(MAKEWORD(Buffer.data()[7],Buffer.data()[6]),MAKEWORD(Buffer.data()[5],Buffer.data()[4]));
        callsign->SetDmrid(uiRptrId, true);
        callsign->SetModule(MMDVM_MODULE_ID);
        valid = callsign->IsValid();
    }
    return valid;
}

bool CDmrmmdvmProtocol::IsValidConfigPacket(const CBuffer &Buffer, CCallsign *callsign, const CIp &Ip)
{
    uint8 tag[] = { 'R','P','T','C' };
    
    bool valid = false;
    if ( (Buffer.size() == 302) && (Buffer.Compare(tag, sizeof(tag)) == 0) )
    {
        uint32 uiRptrId = MAKEDWORD(MAKEWORD(Buffer.data()[7],Buffer.data()[6]),MAKEWORD(Buffer.data()[5],Buffer.data()[4]));
        callsign->SetDmrid(uiRptrId, true);
        callsign->SetModule(MMDVM_MODULE_ID);
        valid = callsign->IsValid();
        if ( !valid)
        {
            std::cout << "DMRmmdvm config packet from IP address " << Ip << " / unrecognized id " << (int)callsign->GetDmrid()  << std::endl;
        }

    }
    return valid;
}

bool CDmrmmdvmProtocol::IsValidOptionPacket(const CBuffer &Buffer, CCallsign *callsign)
{
    uint8 tag[] = { 'R','P','T','O' };
    
    bool valid = false;
    if ( (Buffer.size() >= 8) && (Buffer.Compare(tag, sizeof(tag)) == 0) )
    {
        uint32 uiRptrId = MAKEDWORD(MAKEWORD(Buffer.data()[7],Buffer.data()[6]),MAKEWORD(Buffer.data()[5],Buffer.data()[4]));
        callsign->SetDmrid(uiRptrId, true);
        callsign->SetModule(MMDVM_MODULE_ID);
        valid = callsign->IsValid();
    }
    return valid;
}

bool CDmrmmdvmProtocol::IsValidRssiPacket(const CBuffer &Buffer, CCallsign *callsign, int *rssi)
{
    uint8 tag[] = { 'R','P','T','I','N','T','R' };
    
    bool valid = false;
    if ( (Buffer.size() == 17) && (Buffer.Compare(tag, sizeof(tag)) == 0) )
    {
        // ignore rest of it, as not used
        // dmrid is asci hex on 8 bytes
        // rssi is ascii :x-xx
        valid = true;
    }
    return valid;
}

bool CDmrmmdvmProtocol::IsValidDvHeaderPacket(const CBuffer &Buffer, CDvHeaderPacket **header, uint8 *cmd, uint8 *CallType)
{
    uint8 tag[] = { 'D','M','R','D' };
    
    bool valid = false;
    *header = NULL;
    *cmd = CMD_NONE;
    
    if ( (Buffer.size() == 55) && (Buffer.Compare(tag, sizeof(tag)) == 0) )
    {
        // frame details
        uint8 uiFrameType = (Buffer.data()[15] & 0x30) >> 4;
        uint8 uiSlot = (Buffer.data()[15] & 0x80) ? DMR_SLOT2 : DMR_SLOT1;
        uint8 uiCallType = (Buffer.data()[15] & 0x40) ? DMR_PRIVATE_CALL : DMR_GROUP_CALL;
        uint8 uiSlotType = Buffer.data()[15] & 0x0F;
        //std::cout << (int)uiSlot << std::endl;
        if ( (uiFrameType == DMRMMDVM_FRAMETYPE_DATASYNC) &&
             (uiSlot == DMRMMDVM_REFLECTOR_SLOT) &&
             (uiSlotType == MMDVM_SLOTTYPE_HEADER) )
        {
            // extract sync
            uint8 dmrsync[7];
            dmrsync[0] = Buffer.data()[33] & 0x0F;
            ::memcpy(&dmrsync[1], &Buffer.data()[34], 5);
            dmrsync[6] = Buffer.data()[39] & 0xF0;
            // and check
            if ( (::memcmp(dmrsync, g_DmrSyncMSData, sizeof(dmrsync)) == 0) ||
                 (::memcmp(dmrsync, g_DmrSyncBSData, sizeof(dmrsync)) == 0))
            {
                // get payload
                //CBPTC19696 bptc;
                //uint8 lcdata[12];
                //bptc.decode(&(Buffer.data()[20]), lcdata);
                
                // crack DMR header
                //uint8 uiSeqId = Buffer.data()[4];
                uint32 uiSrcId = MAKEDWORD(MAKEWORD(Buffer.data()[7],Buffer.data()[6]),MAKEWORD(Buffer.data()[5],0));
                uint32 uiDstId = MAKEDWORD(MAKEWORD(Buffer.data()[10],Buffer.data()[9]),MAKEWORD(Buffer.data()[8],0));
                uint32 uiRptrId = MAKEDWORD(MAKEWORD(Buffer.data()[14],Buffer.data()[13]),MAKEWORD(Buffer.data()[12],Buffer.data()[11]));
                //uint8 uiVoiceSeq = (Buffer.data()[15] & 0x0F);
                uint32 uiStreamId = *(uint32 *)(&Buffer.data()[16]);
                
                // call type
                *CallType = uiCallType;
                
                // link/unlink command ?
                if ( uiDstId == 4000 )
                {
                    *cmd = CMD_UNLINK;
                }
                else if ( DmrDstIdToModule(uiDstId) != ' ' )
                {
                    *cmd = CMD_LINK;
                }
                else
                {
                    *cmd = CMD_NONE;
                }
                
                // build DVHeader
                CCallsign csMY = CCallsign("", uiSrcId);
                CCallsign rpt1 = CCallsign("", uiRptrId);
                rpt1.SetModule(MMDVM_MODULE_ID);
                CCallsign rpt2 = m_ReflectorCallsign;
                rpt2.SetModule(DmrDstIdToModule(uiDstId));
                
                // and packet
                *header = new CDvHeaderPacket(uiSrcId, CCallsign("CQCQCQ"), rpt1, rpt2, uiStreamId, 0, 0);
                valid = (*header)->IsValid();
                if ( !valid )
                {
                    delete *header;
                    *header = NULL;
                }
            }
        }
    }
    // done
    return valid;
}

bool CDmrmmdvmProtocol::IsValidDvFramePacket(const CBuffer &Buffer, CDvFramePacket **frames)
{
    uint8 tag[] = { 'D','M','R','D' };
    
    bool valid = false;
    frames[0] = NULL;
    frames[1] = NULL;
    frames[2] = NULL;
    
    if ( (Buffer.size() == 55) && (Buffer.Compare(tag, sizeof(tag)) == 0) )
    {
        // frame details
        uint8 uiFrameType = (Buffer.data()[15] & 0x30) >> 4;
        uint8 uiSlot = (Buffer.data()[15] & 0x80) ? DMR_SLOT2 : DMR_SLOT1;
        uint8 uiCallType = (Buffer.data()[15] & 0x40) ? DMR_PRIVATE_CALL : DMR_GROUP_CALL;
        if ( ((uiFrameType == DMRMMDVM_FRAMETYPE_VOICE) || (uiFrameType == DMRMMDVM_FRAMETYPE_VOICESYNC)) &&
              (uiSlot == DMRMMDVM_REFLECTOR_SLOT) && (uiCallType == DMR_GROUP_CALL) )
        {
            // crack DMR header
            //uint8 uiSeqId = Buffer.data()[4];
            //uint32 uiSrcId = MAKEDWORD(MAKEWORD(Buffer.data()[7],Buffer.data()[6]),MAKEWORD(Buffer.data()[5],0));
            //uint32 uiDstId = MAKEDWORD(MAKEWORD(Buffer.data()[10],Buffer.data()[9]),MAKEWORD(Buffer.data()[8],0));
            //uint32 uiRptrId = MAKEDWORD(MAKEWORD(Buffer.data()[14],Buffer.data()[13]),MAKEWORD(Buffer.data()[12],Buffer.data()[11]));
            uint8 uiVoiceSeq = (Buffer.data()[15] & 0x0F);
            uint32 uiStreamId = *(uint32 *)(&Buffer.data()[16]);
           
            // crack payload
            uint8 dmrframe[33];
            uint8 dmr3ambe[27];
            uint8 dmrambe[9];
            uint8 dmrsync[7];
            // get the 33 bytes ambe
            memcpy(dmrframe, &(Buffer.data()[20]), 33);
            // extract the 3 ambe frames
            memcpy(dmr3ambe, dmrframe, 14);
            dmr3ambe[13] &= 0xF0;
            dmr3ambe[13] |= (dmrframe[19] & 0x0F);
            memcpy(&dmr3ambe[14], &dmrframe[20], 13);
            // extract sync
            dmrsync[0] = dmrframe[13] & 0x0F;
            ::memcpy(&dmrsync[1], &dmrframe[14], 5);
            dmrsync[6] = dmrframe[19] & 0xF0;
            
            // debug
            //CBuffer dump;
            //dump.Set(dmrsync, 6);
            //dump.DebugDump(g_Reflector.m_DebugFile);
            
            // and create 3 dv frames
            // frame1
            memcpy(dmrambe, &dmr3ambe[0], 9);
            frames[0] = new CDvFramePacket(dmrambe, dmrsync, uiStreamId, uiVoiceSeq, 1);
            
            // frame2
            memcpy(dmrambe, &dmr3ambe[9], 9);
            frames[1] = new CDvFramePacket(dmrambe, dmrsync, uiStreamId, uiVoiceSeq, 2);
            
            // frame3
            memcpy(dmrambe, &dmr3ambe[18], 9);
            frames[2] = new CDvFramePacket(dmrambe, dmrsync, uiStreamId, uiVoiceSeq, 3);
            
            // check
            valid = true;
        }
    }
    // done
    return valid;
}

bool CDmrmmdvmProtocol::IsValidDvLastFramePacket(const CBuffer &Buffer, CDvLastFramePacket **frame)
{
    uint8 tag[] = { 'D','M','R','D' };
    
    bool valid = false;
    *frame = NULL;
    
    if ( (Buffer.size() == 55) && (Buffer.Compare(tag, sizeof(tag)) == 0) )
    {
        // frame details
        uint8 uiFrameType = (Buffer.data()[15] & 0x30) >> 4;
        uint8 uiSlot = (Buffer.data()[15] & 0x80) ? DMR_SLOT2 : DMR_SLOT1;
        //uint8 uiCallType = (Buffer.data()[15] & 0x40) ? DMR_PRIVATE_CALL : DMR_GROUP_CALL;
        uint8 uiSlotType = Buffer.data()[15] & 0x0F;
        //std::cout << (int)uiSlot << std::endl;
        if ( (uiFrameType == DMRMMDVM_FRAMETYPE_DATASYNC) &&
            (uiSlot == DMRMMDVM_REFLECTOR_SLOT) &&
            (uiSlotType == MMDVM_SLOTTYPE_TERMINATOR) )
        {
            // extract sync
            uint8 dmrsync[7];
            dmrsync[0] = Buffer.data()[33] & 0x0F;
            ::memcpy(&dmrsync[1], &Buffer.data()[34], 5);
            dmrsync[6] = Buffer.data()[39] & 0xF0;
            // and check
            if ( (::memcmp(dmrsync, g_DmrSyncMSData, sizeof(dmrsync)) == 0) ||
                (::memcmp(dmrsync, g_DmrSyncBSData, sizeof(dmrsync)) == 0))
            {
                // get payload
                //CBPTC19696 bptc;
                //uint8 lcdata[12];
                //bptc.decode(&(Buffer.data()[20]), lcdata);
                
                // crack DMR header
                //uint8 uiSeqId = Buffer.data()[4];
                //uint32 uiSrcId = MAKEDWORD(MAKEWORD(Buffer.data()[7],Buffer.data()[6]),MAKEWORD(Buffer.data()[5],0));
                //uint32 uiDstId = MAKEDWORD(MAKEWORD(Buffer.data()[10],Buffer.data()[9]),MAKEWORD(Buffer.data()[8],0));
                //uint32 uiRptrId = MAKEDWORD(MAKEWORD(Buffer.data()[14],Buffer.data()[13]),MAKEWORD(Buffer.data()[12],Buffer.data()[11]));
                //uint8 uiVoiceSeq = (Buffer.data()[15] & 0x0F);
                uint32 uiStreamId = *(uint32 *)(&Buffer.data()[16]);
                
                // dummy ambe
                uint8 ambe[9];
                ::memset(ambe, 0, sizeof(ambe));
                
                
                // and packet
                *frame = new CDvLastFramePacket(ambe, dmrsync, uiStreamId, 0, 0);
                
                // check
                valid = true;
            }
        }
    }
    // done
    return valid;
}

////////////////////////////////////////////////////////////////////////////////////////
// packet encoding helpers

void CDmrmmdvmProtocol::EncodeKeepAlivePacket(CBuffer *Buffer, CClient *Client)
{
    uint8 tag[] = { 'M','S','T','P','O','N','G' };
    
    Buffer->Set(tag, sizeof(tag));
    uint32 uiDmrId = Client->GetCallsign().GetDmrid();
    Buffer->Append((uint8 *)&uiDmrId, 4);
}

void CDmrmmdvmProtocol::EncodeAckPacket(CBuffer *Buffer, const CCallsign &Callsign)
{
    uint8 tag[] = { 'R','P','T','A','C','K' };
    
    Buffer->Set(tag, sizeof(tag));
}

void CDmrmmdvmProtocol::EncodeConnectAckPacket(CBuffer *Buffer, const CCallsign &Callsign, uint32 AuthSeed)
{
    uint8 tag[] = { 'R','P','T','A','C','K' };
    
    Buffer->Set(tag, sizeof(tag));
    Buffer->Append(AuthSeed);
}

void CDmrmmdvmProtocol::EncodeNackPacket(CBuffer *Buffer, const CCallsign &Callsign)
{
    uint8 tag[] = { 'M','S','T','N','A','K' };
    
    Buffer->Set(tag, sizeof(tag));
}

void CDmrmmdvmProtocol::EncodeClosePacket(CBuffer *Buffer, CClient *Client)
{
    uint8 tag[] = { 'M','S','T','C','L' };
    
    Buffer->Set(tag, sizeof(tag));
}


bool CDmrmmdvmProtocol::EncodeDvHeaderPacket(const CDvHeaderPacket &Packet, uint8 seqid, CBuffer *Buffer) const
{
    uint8 tag[] = { 'D','M','R','D' };
    
    Buffer->Set(tag, sizeof(tag));
    
    // DMR header
    // uiSeqId
    Buffer->Append((uint8)seqid);
    // uiSrcId
    uint32 uiSrcId = Packet.GetMyCallsign().GetDmrid();
    AppendDmrIdToBuffer(Buffer, uiSrcId);
    // uiDstId = TG9
    uint32 uiDstId = 9; // ModuleToDmrDestId(Packet.GetRpt2Module());
    AppendDmrIdToBuffer(Buffer, uiDstId);
    // uiRptrId
    uint32 uiRptrId = Packet.GetRpt1Callsign().GetDmrid();
    AppendDmrRptrIdToBuffer(Buffer, uiRptrId);
    // uiBitField
    uint8 uiBitField =
        (DMRMMDVM_FRAMETYPE_DATASYNC << 4) |
        ((DMRMMDVM_REFLECTOR_SLOT == DMR_SLOT2) ? 0x80 : 0x00) |
        MMDVM_SLOTTYPE_HEADER;
    Buffer->Append((uint8)uiBitField);
    // uiStreamId
    uint32 uiStreamId = Packet.GetStreamId();
    Buffer->Append((uint32)uiStreamId);
    
    // Payload
    AppendVoiceLCToBuffer(Buffer, uiSrcId);
    
    // BER
    Buffer->Append((uint8)0);
    
    // RSSI
    Buffer->Append((uint8)0);
    
    // done
    return true;
}

void CDmrmmdvmProtocol::EncodeDvPacket(
      const CDvHeaderPacket &Header,
      const CDvFramePacket &DvFrame0, const CDvFramePacket &DvFrame1, const CDvFramePacket &DvFrame2,
      uint8 seqid, CBuffer *Buffer) const
{
    uint8 tag[] = { 'D','M','R','D' };
    Buffer->Set(tag, sizeof(tag));
    
    // DMR header
    // uiSeqId
    Buffer->Append((uint8)seqid);
    // uiSrcId
    uint32 uiSrcId = Header.GetMyCallsign().GetDmrid();
    AppendDmrIdToBuffer(Buffer, uiSrcId);
    // uiDstId = TG9
    uint32 uiDstId = 9; // ModuleToDmrDestId(Header.GetRpt2Module());
    AppendDmrIdToBuffer(Buffer, uiDstId);
    // uiRptrId
    uint32 uiRptrId = Header.GetRpt1Callsign().GetDmrid();
    AppendDmrRptrIdToBuffer(Buffer, uiRptrId);
    // uiBitField
    uint8 uiBitField =
        ((DMRMMDVM_REFLECTOR_SLOT == DMR_SLOT2) ? 0x80 : 0x00);
    if ( DvFrame0.GetDmrPacketId() == 0 )
    {
        uiBitField |= (DMRMMDVM_FRAMETYPE_VOICESYNC << 4);
    }
    else
    {
        uiBitField |= (DMRMMDVM_FRAMETYPE_VOICE << 4);
    }
    uiBitField |= (DvFrame0.GetDmrPacketId() & 0x0F);
    Buffer->Append((uint8)uiBitField);
    
    // uiStreamId
    uint32 uiStreamId = Header.GetStreamId();
    Buffer->Append((uint32)uiStreamId);
    
    // Payload
    // frame0
    Buffer->ReplaceAt(20, DvFrame0.GetAmbePlus(), 9);
    // 1/2 frame1
    Buffer->ReplaceAt(29, DvFrame1.GetAmbePlus(), 5);
    Buffer->ReplaceAt(33, (uint8)(Buffer->at(33) & 0xF0));
    // 1/2 frame1
    Buffer->ReplaceAt(39, DvFrame1.GetAmbePlus()+4, 5);
    Buffer->ReplaceAt(39, (uint8)(Buffer->at(39) & 0x0F));
    // frame2
    Buffer->ReplaceAt(44, DvFrame2.GetAmbePlus(), 9);
    
    // sync or embedded signaling
    ReplaceEMBInBuffer(Buffer, DvFrame0.GetDmrPacketId());

    // debug
    //CBuffer dump;
    //dump.Set(&(Buffer->data()[33]), 7);
    //dump.DebugDump(g_Reflector.m_DebugFile);

    // BER
    Buffer->Append((uint8)0);
    
    // RSSI
    Buffer->Append((uint8)0);    
}


void CDmrmmdvmProtocol::EncodeDvLastPacket(const CDvHeaderPacket &Packet, uint8 seqid, CBuffer *Buffer) const
{
    uint8 tag[] = { 'D','M','R','D' };
    
    Buffer->Set(tag, sizeof(tag));
    
    // DMR header
    // uiSeqId
    Buffer->Append((uint8)seqid);
    // uiSrcId
    uint32 uiSrcId = Packet.GetMyCallsign().GetDmrid();
    AppendDmrIdToBuffer(Buffer, uiSrcId);
    // uiDstId
    uint32 uiDstId = 9; //ModuleToDmrDestId(Packet.GetRpt2Module());
    AppendDmrIdToBuffer(Buffer, uiDstId);
    // uiRptrId
    uint32 uiRptrId = Packet.GetRpt1Callsign().GetDmrid();
    AppendDmrRptrIdToBuffer(Buffer, uiRptrId);
    // uiBitField
    uint8 uiBitField =
        (DMRMMDVM_FRAMETYPE_DATASYNC << 4) |
        ((DMRMMDVM_REFLECTOR_SLOT == DMR_SLOT2) ? 0x80 : 0x00) |
        MMDVM_SLOTTYPE_TERMINATOR;
    Buffer->Append((uint8)uiBitField);
    // uiStreamId
    uint32 uiStreamId = Packet.GetStreamId();
    Buffer->Append((uint32)uiStreamId);
    
    // Payload
    AppendTerminatorLCToBuffer(Buffer, uiSrcId);
    
    // BER
    Buffer->Append((uint8)0);
    
    // RSSI
    Buffer->Append((uint8)0);
}


////////////////////////////////////////////////////////////////////////////////////////
// DestId to Module helper

char CDmrmmdvmProtocol::DmrDstIdToModule(uint32 tg) const
{
    // is it a 4xxx ?
    if ( (tg >= 4001) && (tg <= (4000 + NB_OF_MODULES)) )
    {
        return ((char)(tg - 4001) + 'A');
    }
    return ' ';
}

uint32 CDmrmmdvmProtocol::ModuleToDmrDestId(char m) const
{
    return (uint32)(m - 'A')+4001;
}

////////////////////////////////////////////////////////////////////////////////////////
// Buffer & LC helpers

void CDmrmmdvmProtocol::AppendVoiceLCToBuffer(CBuffer *buffer, uint32 uiSrcId) const
{
    uint8 payload[33];
    
    // fill payload
    CBPTC19696 bptc;
    ::memset(payload, 0, sizeof(payload));
    // LC data
    uint8 lc[12];
    {
        ::memset(lc, 0, sizeof(lc));
        // uiDstId = TG9
        lc[5] = 9;
        // uiSrcId
        lc[6] = (uint8)LOBYTE(HIWORD(uiSrcId));
        lc[7] = (uint8)HIBYTE(LOWORD(uiSrcId));
        lc[8] = (uint8)LOBYTE(LOWORD(uiSrcId));
        // parity
        uint8 parity[4];
        CRS129::encode(lc, 9, parity);
        lc[9]  = parity[2] ^ DMR_VOICE_LC_HEADER_CRC_MASK;
        lc[10] = parity[1] ^ DMR_VOICE_LC_HEADER_CRC_MASK;
        lc[11] = parity[0] ^ DMR_VOICE_LC_HEADER_CRC_MASK;
    }
    // sync
    ::memcpy(payload+13, g_DmrSyncBSData, sizeof(g_DmrSyncBSData));
    // slot type
    {
        // slot type
        uint8 slottype[3];
        ::memset(slottype, 0, sizeof(slottype));
        slottype[0]  = (DMRMMDVM_REFLECTOR_COLOUR << 4) & 0xF0;
        slottype[0] |= (DMR_DT_VOICE_LC_HEADER  << 0) & 0x0FU;
        CGolay2087::encode(slottype);
        payload[12U] = (payload[12U] & 0xC0U) | ((slottype[0U] >> 2) & 0x3FU);
        payload[13U] = (payload[13U] & 0x0FU) | ((slottype[0U] << 6) & 0xC0U) | ((slottype[1U] >> 2) & 0x30U);
        payload[19U] = (payload[19U] & 0xF0U) | ((slottype[1U] >> 2) & 0x0FU);
        payload[20U] = (payload[20U] & 0x03U) | ((slottype[1U] << 6) & 0xC0U) | ((slottype[2U] >> 2) & 0x3CU);
        
    }
    // and encode
    bptc.encode(lc, payload);
    
    // and append
    buffer->Append(payload, sizeof(payload));
}

void CDmrmmdvmProtocol::AppendTerminatorLCToBuffer(CBuffer *buffer, uint32 uiSrcId) const
{
    uint8 payload[33];
    
    // fill payload
    CBPTC19696 bptc;
    ::memset(payload, 0, sizeof(payload));
    // LC data
    uint8 lc[12];
    {
        ::memset(lc, 0, sizeof(lc));
        // uiDstId = TG9
        lc[5] = 9;
        // uiSrcId
        lc[6] = (uint8)LOBYTE(HIWORD(uiSrcId));
        lc[7] = (uint8)HIBYTE(LOWORD(uiSrcId));
        lc[8] = (uint8)LOBYTE(LOWORD(uiSrcId));
        // parity
        uint8 parity[4];
        CRS129::encode(lc, 9, parity);
        lc[9]  = parity[2] ^ DMR_TERMINATOR_WITH_LC_CRC_MASK;
        lc[10] = parity[1] ^ DMR_TERMINATOR_WITH_LC_CRC_MASK;
        lc[11] = parity[0] ^ DMR_TERMINATOR_WITH_LC_CRC_MASK;
    }
    // sync
    ::memcpy(payload+13, g_DmrSyncBSData, sizeof(g_DmrSyncBSData));
    // slot type
    {
        // slot type
        uint8 slottype[3];
        ::memset(slottype, 0, sizeof(slottype));
        slottype[0]  = (DMRMMDVM_REFLECTOR_COLOUR << 4) & 0xF0;
        slottype[0] |= (DMR_DT_TERMINATOR_WITH_LC  << 0) & 0x0FU;
        CGolay2087::encode(slottype);
        payload[12U] = (payload[12U] & 0xC0U) | ((slottype[0U] >> 2) & 0x3FU);
        payload[13U] = (payload[13U] & 0x0FU) | ((slottype[0U] << 6) & 0xC0U) | ((slottype[1U] >> 2) & 0x30U);
        payload[19U] = (payload[19U] & 0xF0U) | ((slottype[1U] >> 2) & 0x0FU);
        payload[20U] = (payload[20U] & 0x03U) | ((slottype[1U] << 6) & 0xC0U) | ((slottype[2U] >> 2) & 0x3CU);
    }
    // and encode
    bptc.encode(lc, payload);
    
    // and append
    buffer->Append(payload, sizeof(payload));
}

void CDmrmmdvmProtocol::ReplaceEMBInBuffer(CBuffer *buffer, uint8 uiDmrPacketId) const
{
    // voice packet A ?
    if ( uiDmrPacketId == 0 )
    {
        // sync
        buffer->ReplaceAt(33, (uint8)(buffer->at(33) | (g_DmrSyncBSVoice[0] & 0x0F)));
        buffer->ReplaceAt(34, g_DmrSyncBSVoice+1, 5);
        buffer->ReplaceAt(39, (uint8)(buffer->at(39) | (g_DmrSyncBSVoice[6] & 0xF0)));
    }
    // voice packet B,C,D,E ?
    else if ( (uiDmrPacketId >= 1) && (uiDmrPacketId <= 4 ) )
    {
        // EMB LC
        uint8 emb[2];
        emb[0]  = (DMRMMDVM_REFLECTOR_COLOUR << 4) & 0xF0;
        //emb[0] |= PI ? 0x08U : 0x00;
        //emb[0] |= (LCSS << 1) & 0x06;
        emb[1]  = 0x00;
        // encode
        CQR1676::encode(emb);
        // and append
        buffer->ReplaceAt(33, (uint8)((buffer->at(33) & 0xF0) | ((emb[0U] >> 4) & 0x0F)));
        buffer->ReplaceAt(34, (uint8)((buffer->at(34) & 0x0F) | ((emb[0U] << 4) & 0xF0)));
        buffer->ReplaceAt(34, (uint8)(buffer->at(34) & 0xF0));
        buffer->ReplaceAt(35, (uint8)0);
        buffer->ReplaceAt(36, (uint8)0);
        buffer->ReplaceAt(37, (uint8)0);
        buffer->ReplaceAt(38, (uint8)(buffer->at(38) & 0x0F));
        buffer->ReplaceAt(38, (uint8)((buffer->at(38) & 0xF0) | ((emb[1U] >> 4) & 0x0F)));
        buffer->ReplaceAt(39, (uint8)((buffer->at(39) & 0x0F) | ((emb[1U] << 4) & 0xF0)));
    }
    // voice packet F
    else
    {
        // NULL
        uint8 emb[2];
        emb[0]  = (DMRMMDVM_REFLECTOR_COLOUR << 4) & 0xF0;
        //emb[0] |= PI ? 0x08U : 0x00;
        //emb[0] |= (LCSS << 1) & 0x06;
        emb[1]  = 0x00;
        // encode
        CQR1676::encode(emb);
        // and append
        buffer->ReplaceAt(33, (uint8)((buffer->at(33) & 0xF0) | ((emb[0U] >> 4) & 0x0F)));
        buffer->ReplaceAt(34, (uint8)((buffer->at(34) & 0x0F) | ((emb[0U] << 4) & 0xF0)));
        buffer->ReplaceAt(34, (uint8)(buffer->at(34) & 0xF0));
        buffer->ReplaceAt(35, (uint8)0);
        buffer->ReplaceAt(36, (uint8)0);
        buffer->ReplaceAt(37, (uint8)0);
        buffer->ReplaceAt(38, (uint8)(buffer->at(38) & 0x0F));
        buffer->ReplaceAt(38, (uint8)((buffer->at(38) & 0xF0) | ((emb[1U] >> 4) & 0x0F)));
        buffer->ReplaceAt(39, (uint8)((buffer->at(39) & 0x0F) | ((emb[1U] << 4) & 0xF0)));
    }
}

void CDmrmmdvmProtocol::AppendDmrIdToBuffer(CBuffer *buffer, uint32 id) const
{
    buffer->Append((uint8)LOBYTE(HIWORD(id)));
    buffer->Append((uint8)HIBYTE(LOWORD(id)));
    buffer->Append((uint8)LOBYTE(LOWORD(id)));
}

void CDmrmmdvmProtocol::AppendDmrRptrIdToBuffer(CBuffer *buffer, uint32 id) const
{
    buffer->Append((uint8)HIBYTE(HIWORD(id)));
    buffer->Append((uint8)LOBYTE(HIWORD(id)));
    buffer->Append((uint8)HIBYTE(LOWORD(id)));
    buffer->Append((uint8)LOBYTE(LOWORD(id)));
}