#include "SystemControler.h"
#include <easylogging++.h>
#include "SystemConfig.h"
#include <optional>

using namespace std::chrono;

std::atomic<bool> dataReadingCancelled = false;
std::atomic<bool> updateServerCancelled = false;
std::atomic<bool> threadRunning = false;
std::thread* readDataThread = nullptr;


SystemControler::SystemControler() :
    dataModel(DataModel::Instance()), dataAcquire(std::make_shared<DataAcquisition>())
{
    this->alertReadInterval = SystemConfig::getIntConfigParameter("alert_read_interval");
    this->serverPort = SystemConfig::getIntConfigParameter("tcp_server_port");

    initializePermanentStorage();
}

SystemControler::~SystemControler()
{
    LOG(INFO) << "Wait until continous modbus reading thread finishes...";
    if(readDataThread != nullptr && threadRunning){
        dataReadingCancelled = true;
        if(readDataThread->joinable())
            readDataThread->join();
    }

    LOG(INFO) << "Wait until server update thread finishes...";
    if(serverUpdateThread != nullptr){
        updateServerCancelled = true;
        if(serverUpdateThread->joinable())
            serverUpdateThread->join();
    }
    server.reset();

    if(readDataThread != nullptr)
        delete readDataThread;
    if(serverUpdateThread != nullptr)
        delete serverUpdateThread;

    DataModel::Destroy();
}


void updateServer(std::shared_ptr<NetServer> server, std::chrono::milliseconds ms) {
	auto now = std::chrono::system_clock::now();
	//Run as long as server exists and is not stopped
	while (server != nullptr && !server->isStopped()) {
        if(updateServerCancelled)
            return;

        //Check for alerts
        auto& alerts = DataModel::Instance()->getAlerts();
        while(alerts.size() > 0){
            net::Message<net::MessageTypes> msg;
            auto a = alerts.pop_front();
            msg.header.id = net::MessageTypes::ServerAlert;
            short bitmask = 0;
            std::memcpy(&bitmask, a.readedBytes.data(), 2);
            std::stringstream tmp;
            tmp << "Modbus " << a.connection->getConnectionType() << " alert: " << ModbusDataPOC::getStatusMessage(bitmask);
            msg << tmp.str();
            server->MessageAllClients(msg);
        }

        //check for messages, specify no max message count
		//return if no message is available
        server->Update(-1, false);
		std::this_thread::sleep_until(now + ms);
	}
	return;
}


void SystemControler::startIpTcpServer() {
    try {
        //start server
        if(server == nullptr)
            server = std::make_shared<NetServer>(serverPort);

        if(server->isRunning()){
            LOG(WARNING) << "Invoked server start, but server is already running";
            return;
        }

        server->Start();

        //Continous running update thread, that checks for incomming messages
        serverUpdateThread = new std::thread(updateServer, server, serverTickRateMs);
    }
    catch (asio::system_error& e) {
        LOG(FATAL) << "[SERVER]: Error "
            << e.code() << " >> "
            << e.what();
    }
}



/*
thread whhich acquires data from all registered publishers
->pointer to dataAcquisition, which handles the readiong requests
->intervalSec: # of seconds 
*/
void enqueueRegisterThread(std::shared_ptr<DataAcquisition> dataAcquisition, SystemControler* controler, const u_int intervalSec)
{
	threadRunning = true;
    dataReadingCancelled = false;
    LOG(INFO) << "Started continous data reading";
    while (!dataReadingCancelled) {
		const auto currentTime = system_clock::now();

		//read in the data from the publishers
        dataAcquisition->enqueuePublisherRegister();

        controler->evaluate();
		for (u_int i = 1; i <= intervalSec; i++)
		{
            if (dataReadingCancelled) {
                LOG(INFO) << "Stopped continous data reading";
				threadRunning = false;
                dataReadingCancelled = false;
				return;
			}
			//Wait for 1 additional second and then check for cancelled thread
			std::this_thread::sleep_until(currentTime + std::chrono::seconds(1) * i);
		}
	}
    LOG(INFO) << "Stopped continous data reading";
    dataReadingCancelled = false;
	threadRunning = false;
}

//Invokes continous modbus alert reading
void SystemControler::startEnqueuingRegister()
{
    if (threadRunning && !dataReadingCancelled) {
        LOG(ERROR) << "ILLEGAL STATE: Invoked starting readDataThread while thread is already running (Thread ID: " << readDataThread->get_id() << ")";
        return;
    }
    //Continue thread if it is already cancelled but still running
    else if (threadRunning && dataReadingCancelled) {
        dataReadingCancelled = false;
    }
    else {
        if(readDataThread != nullptr)
            delete readDataThread;
        readDataThread = new std::thread(enqueueRegisterThread, dataAcquire, this, alertReadInterval);
    }
}

//Cancels continous modbus alert reading
void SystemControler::cancelReadingModbusAlerts()
{
    if (dataReadingCancelled){
        LOG(INFO) << "Thread is already cancelled, waiting for thread to stop";
    }
    else if (!threadRunning || readDataThread == nullptr){
        LOG(ERROR) << "ILLEGAL STATE: Invoke cancelling of readDataThread while thread is not running";
    }
    else{
        dataReadingCancelled = true;
        if(readDataThread->joinable())
            readDataThread->join();
    }
}

//Check wether to flush or not, else counts up
void SystemControler::flushAfterNData()
{
	dataModel->checkForFlushData();
}

//delegate register Publisher
void SystemControler::registerPublisher(std::unique_ptr<PublisherInterface> publisher)
{ 
    dataAcquire->registerPublisher(std::move(publisher));
}

void SystemControler::evaluate(){
    if(evaluator == nullptr)
        return;
    auto alerts = evaluator->evaluate();
    for(auto &a : alerts){
        net::Message<net::MessageTypes> msg;
        msg.header.id = net::MessageTypes::ServerAlert;
        msg << a.message;
        server->MessageAllClients(msg);
    }
}


void SystemControler::initializePermanentStorage(){
    //register Residual Current (dummy) to perform linear regression
    //set biased fo ML Algorithm
    dataModel->makePermanent(ModbusRegister::BENDER_Residual_current, true);

    evaluator = std::make_unique<Evaluator>();
}