//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// This program 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 Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public License
// along with this program.  If not, see http://www.gnu.org/licenses/.
// 

#include "PHYenb.h"
#include "RRC.h"
#include "LTEChannelControl.h"

Define_Module(PHYenb);

PHYenb::PHYenb() : PHY() {
    dlBandwith = 6;
    ulBandwith = 6;

    hasBCHPdu = false;

    sfn = 0;
    sf = 0;
    symb = 0;
    slot = 0;

    nRBsc = 12;
    nDLsymb = 7;

    symbPeriod = 1e-3 / nDLsymb;
}

PHYenb::~PHYenb() {
    for (unsigned char i = 0; i < nDLsymb * 2; i++) {
        if (dlSubframe[i])
            delete dlSubframe[i];
    }

	for (unsigned char l = 0; l < nDLsymb * 2; l++)
		for (unsigned short k = 0; k < nRBsc * nDLrb; k++)
			if (dlBuffer[l][k])
				delete dlBuffer[l][k];
}

void PHYenb::initialize(int stage) {
    // TODO - Generated method body
	PHY::initialize(stage);

    if (stage == 2) {
        cc->setRadioChannel(myRadioRef, PRACH);
        cc->setRadioChannel(myRadioRef, PUSCH);
    }

    if (stage == 4) {
        fsm = cFSM("fsm-PHYenb");
        fsm.setState(IDLE);

        nb = NotificationBoardAccess().get();

        nb->subscribe(this, PARAMRequest);
        nb->subscribe(this, CONFIGRequest);
        nb->subscribe(this, STARTRequest);
        nb->subscribe(this, TXRequest);
        nb->subscribe(this, DLCONFIGRequest);
    }
}

void PHYenb::handleMessage(cMessage *msg) {
	if (msg->isSelfMessage()) {
		if (msg == symbolTimer) {
            if (symb == 0 && slot % 2 == 0) {
                cleanup();

                SubframeIndication *sfInd = new SubframeIndication();
                sfInd->setSf(sf);
                sfInd->setSfn(sfn);
                nb->fireChangeNotification(SUBFRAMEIndication, sfInd);
                delete sfInd;

                buildSubframe();
            }

            sendSymbol();

            this->cancelEvent(symbolTimer);
            this->scheduleAt(simTime() + symbPeriod, symbolTimer);

            symb = (symb + 1) % nDLsymb;
            if (symb == 0) {
                slot = (slot + 1) % 20;
                sf = slot / 2;

                if (sf == 0 && slot == 0)
                    sfn++;
            }
		}
	}
}

void PHYenb::handleUpperMessage(cMessage *msg) {
    EV << "LTE-PHYenb: Receiving message with id = " << msg->getKind() << " from upper layer. Buffering the received message.\n";
//    LTEControlInfo *ctrl = check_and_cast<LTEControlInfo*>(msg->removeControlInfo());
//    TransportBlock *tb = new TransportBlock();
//    tb->setName(msg->getName());
//    tb->encapsulate(PK(msg));
//    switch(ctrl->getChannel()) {
//        case BCH:
//        	// TODO repetition of MIB + get the tti rest at PHYue
//            tb->setChannelNumber(PBCH);
//            break;
//        case DLSCH0:
//            tb->setChannelNumber(PDSCH0);
//            break;
//        case DLSCH1:
//            tb->setChannelNumber(PDSCH1);
//            break;
//        default:
//            break;
//    }
//    buffer[msg->getKind()] = tb;
}

void PHYenb::handleRadioMessage(cMessage *msg) {
    PhysicalResourceBlock *prb = check_and_cast<PhysicalResourceBlock*>(msg);
    EV << "LTE-PHYenb: Receiving message from ";

//    if (prb->getChannelNumber() == PRACH) {
//    	EV << "PRACH.\n";
//    	RAPreamble *raPreamble = check_and_cast<RAPreamble*>(prb);
//    	RachIndication *rachInd = new RachIndication();
//    	rachInd->setTti(tti);
//    	rachInd->setPreamblesArraySize(1);
//    	RachPreamble rachPrbl = RachPreamble();
//    	rachPrbl.setPreamble(raPreamble->getRapid());
//    	rachPrbl.setRnti(raPreamble->getRnti());
//    	rachInd->setPreambles(0, rachPrbl);
//    	nb->fireChangeNotification(RACHIndication, rachInd);
//    }
}

void PHYenb::buildSubframe() {
    EV << "LTE-PHYenb: Building downlink subframe for sfn = " << sfn << " and sf = " << (unsigned)sf << ".\n";
	for (unsigned char i = 0; i < nDLsymb * 2; i++) {
		dlSubframe[i] = new PHYSymbol();
		dlSubframe[i]->setResArraySize(nDLrb * nRBsc);
		dlSubframe[i]->setChannelNumber(Downlink);
	}

    unsigned short ssOffset = (nDLrb * nRBsc) / 2 - 31;
    unsigned char vShift = nCellId % 6;

    // PSS
    if ((slot == 0 || slot == 10)) {
    	PHYSymbol *symbol = dlSubframe[nDLsymb - 1];
    	unsigned short k = ssOffset;
        for (; k < ssOffset + 62; k++) {
            symbol->setRes(k, PSS);
        }
        PSSSignal *pss = new PSSSignal();
        pss->setCellIdInGroup(n2id);
        dlBuffer[nDLsymb - 1][k - 1] = pss;
    }

    // SSS
    if ((slot == 0 || slot == 10)) {
    	PHYSymbol *symbol = dlSubframe[nDLsymb - 2];
    	unsigned short k = ssOffset;
        for (; k < ssOffset + 62; k++) {
            symbol->setRes(k, SSS);
        }
        SSSSignal *sss = new SSSSignal();
        sss->setCellGroupId(n1id);
        sss->setSf(sf);
        dlBuffer[nDLsymb - 2][k - 1] = sss;
    }

    // TODO repair RS
    PHYSymbol *symbol1 = dlSubframe[0];
    PHYSymbol *symbol2 = dlSubframe[nDLsymb - 3];
    unsigned char v1 = 0;
    unsigned char v2 = 3;
    unsigned char rsOffset1 = (v1 + vShift) % 6;
    unsigned char rsOffset2 = (v2 + vShift) % 6;
    unsigned char i = 0;
    for (; i < 2 * nDLrb; i++) {
    	symbol1->setRes(rsOffset1 + 6 * i, RS);
    	symbol2->setRes(rsOffset2 + 6 * i, RS);
    }
    ReferenceSignal *refSig = new ReferenceSignal();
    refSig->setCellId(nCellId);
    refSig->setNcp(ncp);
    dlBuffer[0][rsOffset1 + 6 * (i - 1)] = refSig->dup();
    dlBuffer[nDLsymb - 3][rsOffset2 + 6 * (i - 1)] = refSig;

    // PBCH
    if (hasBCHPdu && slot == 1) {
        unsigned char pbchOffset = nDLrb * nRBsc / 2 - 36;
        for (unsigned char l = 0; l < 4; l++) {
            PHYSymbol *symbol = dlSubframe[nDLsymb + l];
            for (unsigned short k = pbchOffset; k < pbchOffset + 72; k++) {
                symbol->setRes(k, PBCH);
            }
        }
    }

    // PCFICH
    if (dciBuffer.size() != 0 && cfi != 0) {
		PHYSymbol *symbol = dlSubframe[0];
		unsigned char pcfichOffset = (nRBsc / 2) * (nCellId % (2 * nDLrb));
		unsigned short kLast = 0;
		for (unsigned i = 0; i < 4; i++) {
			unsigned short k = (pcfichOffset + (unsigned)(i * nDLrb / 2) * nRBsc / 2) % (nDLrb * nRBsc);
			REG reg = findExactReg(0, k);
			if (reg) {
				unsigned char kRel = 0;
				for (; kRel < getReNrInReg(0); kRel++) {
					if (!symbol->getRes(reg[kRel].k))	// avoid resource elements assigned for RS
						symbol->setRes(reg[kRel].k, PCFICH);
				}
				kLast = reg[kRel - 1].k;
			} else {
				EV << "LTE-PHYenb: !!! Error in PCFICH, resource element (k,l) does not represent a resource element group !!!\n";
			}
		}
		PCFICHMessage *pcfichMsg = new PCFICHMessage();
		pcfichMsg->setCfi(cfi);
		dlBuffer[0][kLast] = pcfichMsg;
    }

    // PDCCH
    if (dciBuffer.size() != 0 && cfi != 0) {
//    	unsigned char m = 0;
    	unsigned short k = 0;
    	DlConfigRequestDciDlPdu *dciDlPdu = NULL;
    	unsigned char dciSize = 0;

    	while (k < nDLrb * nRBsc && dciBuffer.size() != 0) {
    		unsigned char l = 0;
    		while (l < cfi && dciBuffer.size() != 0) {
				PHYSymbol *symbol = dlSubframe[l];
				REG reg = findExactReg(l, k);

				if (reg && symbol->getRes(k) != PCFICH) {	// TODO PHICH
					// symbol preparation
					unsigned short kLast = 0;
					unsigned char kRel = 0;
					for (; kRel < getReNrInReg(l); kRel++) {
						if (!symbol->getRes(reg[kRel].k))	// avoid resource elements assigned for RS
							symbol->setRes(reg[kRel].k, PDCCH);
					}
					kLast = reg[kRel - 1].k;

					// data transmission
					dciDlPdu = dciBuffer.back();
					if (dciSize == 0) {
						if (dciDlPdu->getType() == DCI_FORMAT_1 || dciDlPdu->getType() == DCI_FORMAT_1A)
							dciSize = 18;
					}
					dciSize--;
					if (dciSize == 0) {
						DCIFormat *dci = new DCIFormat();
					    dci->setRnti(dciDlPdu->getRnti());   // scrambled in CRC
					    dci->setRntiType(dciDlPdu->getRntiType());
					    dci->setFormatFlag(dciDlPdu->getType());
					 	dci->setVrbFlag(dciDlPdu->getVrbFlag());
					 	dci->setRbCoding(dciDlPdu->getRbCoding());
					 	// TODO 2 transport blocks
					 	dci->setMcs(dciDlPdu->getMcs1());
					 	dci->setRv(dciDlPdu->getRv1());
					 	dci->setTpc(dciDlPdu->getTpc());
					 	dlBuffer[l][kLast] = dci;

						dciBuffer.pop_back();
						delete dciDlPdu;
					}
//					m++;
				}
				l++;
    		}
    		k++;
    	}
    }
}

void PHYenb::cleanup() {
	cfi = 0;

    if (sfn % 4 == 0 && sf == 0) {
    	hasBCHPdu = false;
    }
}

void PHYenb::sendSymbol() {
	PHYSymbol *symbol = dlSubframe[symb + (slot % 2) * nDLsymb];

	for (unsigned short k = 0; k < nRBsc * nDLrb; k++) {
		if (dlBuffer[symb + (slot % 2) * nDLsymb][k]) {
			setData(k, dlBuffer[symb + (slot % 2) * nDLsymb][k]);
			dlBuffer[symb + (slot % 2) * nDLsymb][k] = NULL;
		}
	}

	sendToChannel(symbol);
	dlSubframe[symb + (slot % 2) * nDLsymb] = NULL;
}

void PHYenb::setData(unsigned short k, PHYFrame *frame) {
    if (dynamic_cast<LTEChannelControl*>(cc) != NULL) {
        dynamic_cast<LTEChannelControl*>(cc)->setData(k, frame);
    }
}

void PHYenb::stateEntered(int category, const cPolymorphic *details) {
    switch(fsm.getState()) {
        case IDLE: {
            ParamResponse *paramResp = new ParamResponse();
            paramResp->setErrorCode(MsgOk);
            paramResp->setTlvsArraySize(1);
            paramResp->setTlvs(0, createPhyCommandTlv(PhyState, 1, IDLE));
            nb->fireChangeNotification(PARAMResponse, paramResp);
            break;
        }
        case CONFIGURED: {
            if (category == CONFIGRequest) {
            	ConfigRequest *cfgReq = check_and_cast<ConfigRequest*>(details);
            	for (unsigned i = 0; i < cfgReq->getTlvsArraySize(); i++) {
            		if (cfgReq->getTlvs(i).getTag() == SfnSf) {
            			sfn = cfgReq->getTlvs(i).getValue() / 10;
            			sf = cfgReq->getTlvs(i).getValue() % 10;
            		}
                    if (cfgReq->getTlvs(i).getTag() == DlCyclicPrefixType) {
                        ncp = cfgReq->getTlvs(i).getValue() == CTRL_CP_NORMAL ? PHY_CP_NORMAL : PHY_CP_EXTENDED;
                    }
                    if (cfgReq->getTlvs(i).getTag() == TxAntennaPorts) {
                        p = cfgReq->getTlvs(i).getValue();
                    }
                    if (cfgReq->getTlvs(i).getTag() == DlChannelBandwith) {
                        nDLrb = cfgReq->getTlvs(i).getValue();
                    }
                    if (cfgReq->getTlvs(i).getTag() == PhysicalCellId) {
                        nCellId = cfgReq->getTlvs(i).getValue();
                        n1id = nCellId / 3;
                        n2id = nCellId % 3;
                    }
            	}
                ConfigResponse *cfgResp = new ConfigResponse();
                cfgResp->setErrorCode(MsgOk);
                nb->fireChangeNotification(CONFIGResponse, cfgResp);
            }
            break;
        }
        case RUNNING: {
            if (category == STARTRequest) {
            	dlSubframe = new PHYSymbol*[nDLsymb * 2];
            	for (unsigned char i = 0; i < nDLsymb * 2; i++)
            		dlSubframe[i] = NULL;

            	dlBuffer = new PHYFramePtr*[nDLsymb * 2];
            	for (unsigned char l = 0; l < nDLsymb * 2; l++) {
            		dlBuffer[l] = new PHYFramePtr[nRBsc * nDLrb];
            		for (unsigned short k = 0; k < nRBsc * nDLrb; k++)
            			dlBuffer[l][k] = NULL;
            	}

            	configureRegs();

                this->cancelEvent(symbolTimer);
                this->scheduleAt(simTime(), symbolTimer);
            } else if (category == DLCONFIGRequest) {
    			DlConfigRequest *dlCfgReq = check_and_cast<DlConfigRequest*>(details);
    			cfi = dlCfgReq->getNrPdcchSymb();

    		    while (dlCfgReq->getPdusArraySize() != 0) {
    		    	DlConfigRequestPduPtr pdu = dlCfgReq->backPdu();
    		    	EV << "LTE-PHYenb: Received DLCONFIGRequest for PDU with type = " << (unsigned)pdu->getType() << ".\n";

    		    	// DCI request from upper layer
    		    	if (pdu->getType() == DciDlPdu) {
    		    		DlConfigRequestDciDlPdu *dciDlPdu = check_and_cast<DlConfigRequestDciDlPdu*>(pdu);
    		    		dciBuffer.push_back(dciDlPdu);
    		    	} else {
    		    		delete pdu;
    		    	}
    //		    	if (pdu->getType() == BchPdu) {
    //		            hasBCHPdu = true;
    //		            unsigned char pbchOffset = nDLrb * nRBsc / 2 - 36;
    //
    //		            PBCHMessage *frame = new PBCHMessage();
    //		            frame->setCellId(nCellId);
    //		            dlBuffer[nDLsymb + 3][pbchOffset + 71] = frame;
    //		            dlCfgReq[pdu->getPduIndex()] = frame;
    //		        } else if (pdu->getType() == DciDlPdu) {
    ////		    		sendDCIFormat(pdu);
    //		    	} else {
    ////		    		dlCfgReqs[pdu->getPduIndex()] = pdu;
    //		    	}
    		    	dlCfgReq->popPdu();
    		    }
            }
            break;
        }
        default:
            EV << "LTE-PHYenb: Unknown state.\n";
            break;
    }

	if (fsm.getState() == RUNNING) {
		if (category == DLCONFIGRequest) {

		} else if (category == TXRequest) {
//			TxRequest *txReq = check_and_cast<TxRequest*>(details);
//			for (unsigned i = 0; i < txReq->getPdusArraySize(); i++) {
//				TxRequestPdu pdu = txReq->getPdus(i);
//				DlConfigRequests::iterator dlCfgIt = dlCfgReqs.find(pdu.getPduIndex());
//				if (dlCfgIt != dlCfgReqs.end()) {
//					for (unsigned j = 0; j < pdu.getMsgKindsArraySize(); j++) {
//						short msgKind = pdu.getMsgKinds(j);
//						EV << "LTE-PHYenb: Received TXRequest for PDU with id = " << msgKind << ".\n";
//						txReqs[msgKind] = dlCfgIt->second;
//					}
//				}
//			}
		}
	}
//	delete details;

}

void PHYenb::receiveChangeNotification(int category, const cPolymorphic *details) {
    Enter_Method_Silent();

    int oldState = fsm.getState();

    switch(oldState) {
        case IDLE:
            switch(category) {
                case PARAMRequest: {
                    break;
                }
                case CONFIGRequest: {
                    FSM_Goto(fsm, CONFIGURED);
                    break;
                }
                default:
                    EV << "LTE-PHYenb: Received unexpected event.\n";
                    break;
            }
            break;
        case CONFIGURED:
            switch(category) {
                case STARTRequest: {
                    FSM_Goto(fsm, RUNNING);
                    break;
                }
                default:
                    EV << "LTE-PHYenb: Received unexpected event.\n";
                    break;
            }
            break;
        case RUNNING:
            switch(category) {
                case DLCONFIGRequest: {
                    break;
                }
                case TXRequest : {
                    break;
                }
                default:
                    EV << "LTE-PHYenb: Received unexpected event.\n";
                    break;
            }
            break;
        default:
            EV << "LTE-PHYenb: Unknown state.\n";
            break;
    }

//    if (oldState != fsm.getState())
//        EV << "LTE-PHY: PSM-Transition: " << stateName(oldState) << " --> " << stateName(fsm.getState()) << "  (event was: " << eventName(category) << ")\n";
//    else
//        EV << "LTE-PHY: Staying in state: " << stateName(fsm.getState()) << " (event was: " << eventName(category) << ")\n";

    stateEntered(category, details);
}

void PHYenb::sendBufferedData() {
	unsigned short rnti = 0;

//	DlConfigRequests::iterator dlCfgReqsIt = dlCfgReqs.find(tti);
//	if (dlCfgReqsIt != dlCfgReqs.end()) {	// first check downlink configuration requests
//		EV << "LTE-PHYenb: Found DLConfigRequest for tti = " << tti << ".\n";
//
//		while(!dlCfgReqsIt->second.empty()) {
//			DlConfigRequestPduPtr dlCfgReqPdu = dlCfgReqsIt->second.front();
//
//			// find rnti to add to transport block
//			if (dlCfgReqPdu->getType() == DlschPdu) {
//				DlConfigRequestDlschPdu *dlCfgReqDlschPdu = check_and_cast<DlConfigRequestDlschPdu*>(dlCfgReqPdu);
//				rnti = dlCfgReqDlschPdu->getRnti();
//			}
//
//			dlCfgReqsIt->second.pop_front();
//			TxRequests::iterator txReqsIt = txReqs.find(dlCfgReqPdu->getPduIndex());
//			if (txReqsIt != txReqs.end()) {	// second check transmission requests
//				EV << "LTE-PHYenb: Found TxRequest for pduIndex = " << dlCfgReqPdu->getPduIndex() << ".\n";
//
//				while(!txReqsIt->second.empty()) {
//					short msgKind = txReqsIt->second.front();
//					txReqsIt->second.pop_front();
//
//					TransmissionBuffer::iterator bufferIt = buffer.find(msgKind);
//					if (bufferIt != buffer.end()) {	// send transportblock from the buffer
//
//						EV << "LTE-PHYenb: Sending buffered transport block with id = " << msgKind << " to the air.\n";
//						TransportBlock *tb = bufferIt->second;
//						tb->setRnti(rnti);
//						sendToChannel(tb);
//						buffer.erase(bufferIt);
//					}
//				}
//			}
//			delete dlCfgReqPdu;
//		}
//		dlCfgReqs.erase(dlCfgReqsIt);
//	}
}

void PHYenb::sendDCIFormat(DlConfigRequestPduPtr pdu) {
//    DlConfigRequestDciDlPdu *dciPdu = check_and_cast<DlConfigRequestDciDlPdu*>(pdu);
//    DCIFormat *dci = new DCIFormat();
//    dci->setName("DCIFormat");
//    dci->setRnti(dciPdu->getRnti());
////    dci->setRntiType(dciPdu->getRntiType());
//    dci->setChannelNumber(PDCCH);
//    sendToChannel(dci);
}
//
//bool PHYenb::findAndRemoveDlConfigRequestPdu(unsigned short pduIndex) {
//    DlConfigRequestPdus::iterator i = dlCfgReqPdus.find(pduIndex);
//    if (i != dlCfgReqPdus.end()) {
//    	delete i->second;
//        dlCfgReqPdus.erase(i);
//        return true;
//    } else {
//        return false;
//    }
//}
//
//bool PHYenb::findAndRemoveTxRequestPdu(unsigned msgId) {
//    TxRequestPdus::iterator i = txReqPdus.find(msgId);
//    if (i != txReqPdus.end()) {
//    	txReqPdus.erase(i);
//        return true;
//    } else {
//        return false;
//    }
//}