#include <QtNetwork/QtNetwork>
#include <QApplication>
#include <QMessageBox>

#include "ProjectionModel.h"
#include "Screen.h"
#include "Scene.h"
#include "Channel.h"
#include "Exporter.h"
#include "GUIControler.h"

#include "RSync.h"

using namespace projection;

/**
 * Constructor.
 *
 * @param pModel Projection model.
 */
RSync::RSync(ProjectionModel* pModel) : QObject()
{
    m_pModel = pModel;

    m_hostName = QHostInfo::localHostName();
    m_pTcpServer = NULL;
    m_pTcpClient = NULL;
    m_portNo = DEFAULT_PORT_NO;
    m_serverAddress = QHostInfo::localHostName();

    m_bBlockSync = false;
}

/**
 * Destructor.
 */
RSync::~RSync()
{
    if (!m_bServer)
        sendChanges(RSYNC_COMMAND_DISCONNECT, "Disconnect");

    if (m_pTcpServer)
        delete m_pTcpServer;
    if (m_pTcpClient)
        delete m_pTcpClient;
}

/**
 * Initialize as a server.
 *
 * @param portNo Port number.
 */
void RSync::initServer(int portNo)
{
    m_bServer = true;

    if (portNo != 0)
        m_portNo = portNo;

    m_bServer = true;

//return;

    m_pTcpServer = new QTcpServer(m_pModel);
    if (!m_pTcpServer->listen(QHostAddress::Any, m_portNo)) {
        QMessageBox::critical(NULL, APPLICATION_NAME,
                              QString("Unable to start the server: %1.").arg(m_pTcpServer->errorString()));
        return;
    }
    connect(m_pTcpServer, SIGNAL(newConnection()), this, SLOT(acceptNewClient()));
}

/**
 * Initialize as a client.
 *
 * @param address Client address.
 * @param portNo Port number.
 */
void RSync::initClient(const QString& address, int portNo)
{
    m_bServer = false;

    if (!address.isEmpty()) m_serverAddress = address;
    if (portNo != 0) m_portNo = portNo;

    m_pTcpClient = new QTcpSocket(this);
    m_pTcpClient->setReadBufferSize(0);
    connect(m_pTcpClient, SIGNAL(readyRead()), this, SLOT(recvSettings()));
    connect(m_pTcpClient, SIGNAL(error(QAbstractSocket::SocketError)), this, SLOT(displayNetworkError(QAbstractSocket::SocketError)));

    connectToServer();
}

/**
 * Send a sync command to clients.
 *
 * @param command Synchronize command.
 * @param command Synchronize data.
 */
void RSync::sendChanges(RSYNC_COMMAND command, const QString& data)
{
    if (m_bBlockSync)
        return;

    QByteArray block;
    QDataStream out(&block, QIODevice::WriteOnly);
    out.setVersion(QDataStream::Qt_4_5);
    out << (quint32)0;
    out << (int)command;
    out << data;
    out.device()->seek(0);
    out << (quint32)(block.size() - sizeof(quint32));

    for (int i=0; i<m_pClientConnections.size(); ++i)
    {
        if (m_pClientConnections[i]->isValid()) {
            m_pClientConnections[i]->write(block);
            m_pClientConnections[i]->flush();
        }
    }
}

/**
 * Send a reload command to clients.
 */
void RSync::sendReloadSettings()
{
    if (m_bBlockSync)
        return;

    if (m_bServer)
    {
        QDomDocument doc;
        m_pModel->storeSettings(doc);
        sendChanges(RSYNC_COMMAND_RELOAD, doc.toString(0));
    }
}

/**
 * Connect to a server.
 */
void RSync::connectToServer()
{
    m_pTcpClient->abort();
    m_pTcpClient->connectToHost(m_serverAddress, m_portNo);
}

/**
 * Called when a new client connects to the server. Send all states to synchronize.
 */
void RSync::acceptNewClient()
{
    QDomDocument doc;
    m_pModel->storeSettings(doc);

    QByteArray block;
    QDataStream out(&block, QIODevice::WriteOnly);
    out.setVersion(QDataStream::Qt_4_5);
    out << (quint32)0;
    out << (int)RSYNC_COMMAND_INIT;
    out << doc.toString(0);
    out.device()->seek(0);
    out << (quint32)(block.size() - sizeof(quint32));

    QTcpSocket* pClientConnection = m_pTcpServer->nextPendingConnection();
//  connect(pClientConnection, SIGNAL(disconnected()),
//            pClientConnection, SLOT(deleteLater()));
    m_pClientConnections.push_back(pClientConnection);

    m_pModel->getGUI()->showStatusBarMessage(QString("%1 connected").arg(pClientConnection->peerAddress().toString()), 2000);

    pClientConnection->write(block);
    pClientConnection->flush();
//  pClientConnection->disconnectFromHost();

	// Inform Clients about acutal loaded Scene/Model/Screen
	m_pModel->getScreen()->notifyRedraw();
}

/**
 * Called when a new synchronize message is received.
 */
void RSync::recvSettings()
{
    QDataStream in(m_pTcpClient);
    in.setVersion(QDataStream::Qt_4_5);


    while (m_pTcpClient->bytesAvailable() > 0)
    {
        static quint32 blockSize = 0;
        if (blockSize == 0) {
            if (m_pTcpClient->bytesAvailable() < (int)sizeof(quint32))
                return;
            in >> blockSize;
        }

        if (m_pTcpClient->bytesAvailable() < blockSize)
            return;

        int command;
        in >> command;

        QString data;
        in >> data;

        blockSize = 0;

        switch (command)
        {
            case RSYNC_COMMAND_INIT:
            {
                m_lastErrorString = "";
                m_pModel->getGUI()->appendClientLog(tr("Connected to server : %1:%2.").arg(m_serverAddress).arg(m_portNo));

                QDomDocument doc;
                doc.setContent(data);
                m_pModel->restoreSettings(doc);
                break;
            }
            case RSYNC_COMMAND_VIEWPOINT:
            {
                m_pModel->getScene()->setCameraViewpoint(data);
                break;
            }
            case RSYNC_COMMAND_EXPORT:
            {
                QDomDocument doc;
                doc.setContent(data);
                m_pModel->getExporter()->initFromDOMElement(doc.firstChildElement("Exporter"));
                break;
            }
            case RSYNC_COMMAND_MODEL:
            {
                QDomDocument doc;
                doc.setContent(data);
                m_pModel->initFromDOMElement(doc.firstChildElement("Model"));
                break;
            }
            case RSYNC_COMMAND_SCENE:
            {
                QDomDocument doc;
                doc.setContent(data);
                m_pModel->getScene()->initFromDOMElement(doc.firstChildElement("Scene"));
                break;
            }
            case RSYNC_COMMAND_SCREEN:
            {
                QDomDocument doc;
                doc.setContent(data);
                m_pModel->getScreen()->initFromDOMElement(doc.firstChildElement("Screen"));
                break;
            }
            case RSYNC_COMMAND_CHANNEL:
            {
                QDomDocument doc;
                doc.setContent(data);
                QDomElement channel = doc.firstChildElement("Channel");
                QString channelName = channel.attribute("name");
                for (unsigned int i=0; i<m_pModel->getNumChannels(); ++i) {
                    if (channelName == m_pModel->getChannel(i)->getName())
                        m_pModel->getChannel(i)->initFromDOMElement(channel, APPLICATION_VERSION);
                }
                break;
            }
            case RSYNC_COMMAND_GUI:
            {
                QDomDocument doc;
                doc.setContent(data);
                m_pModel->getGUI()->initFromDOMElement(doc.firstChildElement("GUI"));
                break;
            }
            case RSYNC_COMMAND_RELOAD:
            {
                QDomDocument doc;
                doc.setContent(data);
                m_pModel->restoreSettings(doc);
                break;
            }
            case RSYNC_COMMAND_EXPORTFILE:
            {
                m_pModel->getExporter()->exportDataset(data);
                break;
            }
            case RSYNC_COMMAND_DISCONNECT:
            {
                m_pModel->removeAllChannels();
                m_lastErrorString = "";
                m_pModel->getGUI()->appendClientLog(tr("Connection shutdowned."));

                connectToServer();
                break;
            }
            case RSYNC_COMMAND_END:
            {
                qApp->closeAllWindows();
            }
        }
    }
}

/**
 * Called when a network error is occured.
 */
void RSync::displayNetworkError(QAbstractSocket::SocketError socketError)
{
/*
    switch (socketError) {
    case QAbstractSocket::RemoteHostClosedError:
        break;
    case QAbstractSocket::HostNotFoundError:
        QMessageBox::information(NULL, APPLICATION_NAME,
                                 tr("The host was not found. Please check the "
                                    "host name and port settings."));
        break;
    case QAbstractSocket::ConnectionRefusedError:
        QMessageBox::information(NULL, APPLICATION_NAME,
                                 tr("The connection was refused by the peer. "
                                    "Make sure the Multichannnel Projection Designer server is running, "
                                    "and check that the host name and port settings are correct."));
        break;
    default:
        QMessageBox::information(NULL, APPLICATION_NAME,
                                 tr("The following error occurred: %1.")
                                 .arg(m_pTcpClient->errorString()));
    }
*/

    if (socketError != QAbstractSocket::UnknownSocketError &&
        m_lastErrorString != m_pTcpClient->errorString())
    {
        m_pModel->removeAllChannels();
        m_lastErrorString = m_pTcpClient->errorString();
        m_pModel->getGUI()->appendClientLog(m_lastErrorString);
        m_pModel->getGUI()->appendClientLog(tr("Try connecting again..."));
    }

    QTimer* pTimer = new QTimer(this);
    connect(pTimer, SIGNAL(timeout()), this, SLOT(connectToServer()));
    pTimer->setSingleShot(true);
    pTimer->start(1000);
}

/**
 * Set sync message blocking.
 *
 * @param bBlock True to block sending sync data to clients.
 */
void RSync::setBlockSync(bool bBlock)
{
    m_bBlockSync = bBlock;
}

/**
 * Check whether sync message is blocked or not.
 *
 * @param bBlock True to block sending sync data to clients.
 */
bool RSync::getBlockSync() const
{
    return m_bBlockSync;
}