//BTP-------------------------------------------------------------------------------
//BTPRequest

type record ExtBtpPayload {
  //DecodedBtpPayload decodedPayload optional,
  BtpRawPayload rawPayload
} with { variant "" };

type record ExtBtpReq {
  OCT1           nextheader,
  BtpHeader      header,
  ExtBtpPayload  payload optional
} with { variant (header)  "CROSSTAG( btpAHeader, nextheader = '01'O; 
  btpBHeader, nextheader = '02'O; )"  };

external function f_enc_ExtBtpReq(in ExtBtpReq pdu) return octetstring

with { extension "prototype(convert)"
  extension "encode(RAW)"
};

function f_enc_BtpReq(in BtpReq pdu) return octetstring
{

  var ExtBtpReq v_ExtBtpReq

  v_ExtBtpReq.nextheader:='00'O;
  v_ExtBtpReq.header:=pdu.msgOut.header;
  v_ExtBtpReq.payload.rawPayload:=pdu.msgOut.payload.rawPayload;

  //Temporary hack 
  //v_ExtBtpReq.payload.decodedPayload:=omit;


  return f_enc_ExtBtpReq(v_ExtBtpReq);
}



//BtpIndication
type record ExtBtpInd {
  OCT1           nextheader,
  BtpHeader      header,
  octetstring    rawPayload optional
} with { variant (header)  "CROSSTAG( btpAHeader, nextheader = '01'O; 
  btpBHeader, nextheader = '02'O; )"  };

external function f_dec_ExtBtpInd(in octetstring stream) return ExtBtpInd
with { extension "prototype(convert)"
  extension "decode(RAW)"
  extension "errorbehavior(ALL:WARNING)"
};

function f_dec_BtpInd(in octetstring stream) return BtpInd {

  var ExtBtpInd v_ExtBtpInd:=f_dec_ExtBtpInd(stream)

  var BtpInd v_BtpInd

  v_BtpInd.msgIn.header:=v_ExtBtpInd.header;
  if (ispresent(v_ExtBtpInd.rawPayload)) {
    v_BtpInd.msgIn.payload.rawPayload:=v_ExtBtpInd.rawPayload;

    var DecodedBtpPayload v_decodedPayload;
    if (v_ExtBtpInd.nextheader == '01'O) { //BTP A Header
      v_decodedPayload := 
          decodeBTPPayload(v_ExtBtpInd.rawPayload, 
                           v_ExtBtpInd.header.btpAHeader.destinationPort);
    } else if (v_ExtBtpInd.nextheader == '02'O) { //BTP B Header
      v_decodedPayload := 
          decodeBTPPayload(v_ExtBtpInd.rawPayload, 
                           v_ExtBtpInd.header.btpBHeader.destinationPort);
    }

    if (isbound(v_decodedPayload)) {
      v_BtpInd.msgIn.payload.decodedPayload := v_decodedPayload;
    } else {
      v_BtpInd.msgIn.payload.decodedPayload := omit;
    }
  } else
  {
    v_BtpInd.msgIn.payload := omit;
  }

  return v_BtpInd

}

function decodeBTPPayload(octetstring rawPayload, integer destinationPort) 
  return DecodedBtpPayload {
    var DecodedBtpPayload v_decodedPayload;
    if (destinationPort == 2001) 
    {
      v_decodedPayload := { camPacket := dec_CAM_PDU(rawPayload)}
    } else if (destinationPort == 2002) {
      v_decodedPayload := { denmPacket := dec_DENM_PDU(rawPayload)}
    } else if (destinationPort == 2003) {
      v_decodedPayload := { mapPacket := dec_MAP_PDU(rawPayload)}
    } else if (destinationPort == 2004) {
      v_decodedPayload := { spatPacket := dec_SPAT_PDU(rawPayload)}
    } //TODO: Handle destinationPort == 2005
    return v_decodedPayload;
}

function isWellKnownBTPPort(integer prt) return boolean {
  return ((prt >= 2001) and (prt <= 2005));

}