/*

 * Hedgewars, a free turn based strategy game

 * Copyright (c) 2006-2007 Igor Ulyanov <iulyanov@gmail.com>

 * Copyright (c) 2004-2015 Andrey Korotaev <unC0Rr@gmail.com>

 *

 * This program 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; version 2 of the License

 *

 * 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */

#include <QList>

#include <QImage>

#include <QThread>

#include <QApplication>

#include <QProcessEnvironment>

#include "tcpBase.h"

#include "hwconsts.h"

#include "MessageDialog.h"

#include "gameuiconfig.h"

#ifdef HWLIBRARY

extern "C" {

    void RunEngine(int argc, char ** argv);

    int operatingsystem_parameter_argc;

    char ** operatingsystem_parameter_argv;

}

EngineInstance::EngineInstance(QObject *parent)

    : QObject(parent)

{

}

EngineInstance::~EngineInstance()

{

    qDebug() << "EngineInstance delete" << QThread::currentThreadId();

}

void EngineInstance::setArguments(const QStringList & arguments)

{

    m_arguments.clear();

    m_arguments << qApp->arguments().at(0).toUtf8();

    m_argv.resize(arguments.size() + 1);

    m_argv[0] = m_arguments.last().data();

    int i = 1;

    foreach(const QString & s, arguments)

    {

        m_arguments << s.toUtf8();

        m_argv[i] = m_arguments.last().data();

        ++i;

    }

}

void EngineInstance::start()

{

    qDebug() << "EngineInstance start" << QThread::currentThreadId();

    RunEngine(m_argv.size(), m_argv.data());

    emit finished();

}

#endif

QList<TCPBase*> srvsList;

QPointer<QTcpServer> TCPBase::IPCServer(0);

TCPBase::~TCPBase()

{

    if(m_hasStarted)

    {

        if(IPCSocket)

            IPCSocket->close();

        if(m_connected)

        {

#ifdef HWLIBRARY

            if(!thread)

                qDebug("WTF");

            thread->quit();

            thread->wait();

#else

            process->waitForFinished(1000);

#endif

        }

    }

    // make sure this object is not in the server list anymore

    srvsList.removeOne(this);

    if (IPCSocket)

        IPCSocket->deleteLater();

}

TCPBase::TCPBase(bool demoMode, bool usesCustomLanguage, QObject *parent) :

    QObject(parent),

    m_hasStarted(false),

    m_isDemoMode(demoMode),

    m_connected(false),

    m_usesCustomLanguage(usesCustomLanguage),

    IPCSocket(0)

{

    process = 0;

    if(!IPCServer)

    {

        IPCServer = new QTcpServer(0);

        IPCServer->setMaxPendingConnections(1);

        if (!IPCServer->listen(QHostAddress::LocalHost))

        {

            MessageDialog::ShowFatalMessage(tr("Unable to start server at %1.").arg(IPCServer->errorString()));

            exit(0); // FIXME - should be graceful exit here (lower Critical -> Warning above when implemented)

        }

    }

    ipc_port=IPCServer->serverPort();

}

void TCPBase::NewConnection()

{

    if(IPCSocket)

    {

        // connection should be already finished

        return;

    }

    disconnect(IPCServer, SIGNAL(newConnection()), this, SLOT(NewConnection()));

    IPCSocket = IPCServer->nextPendingConnection();

    if(!IPCSocket) return;

    m_connected = true;

    connect(IPCSocket, SIGNAL(disconnected()), this, SLOT(ClientDisconnect()));

    connect(IPCSocket, SIGNAL(readyRead()), this, SLOT(ClientRead()));

    SendToClientFirst();

    if(simultaneousRun())

    {

        srvsList.removeOne(this);

        emit isReadyNow();

    }

}

void TCPBase::RealStart()

{

    connect(IPCServer, SIGNAL(newConnection()), this, SLOT(NewConnection()));

    IPCSocket = 0;

#ifdef HWLIBRARY

    thread = new QThread(this);

    EngineInstance *instance = new EngineInstance();

    instance->setArguments(getArguments());

    instance->moveToThread(thread);

    connect(thread, SIGNAL(started()), instance, SLOT(start(void)));

    connect(instance, SIGNAL(finished()), thread, SLOT(quit()));

    connect(instance, SIGNAL(finished()), instance, SLOT(deleteLater()));

    connect(instance, SIGNAL(finished()), thread, SLOT(deleteLater()));

    thread->start();

#else

    process = new QProcess(this);

    connect(process, SIGNAL(error(QProcess::ProcessError)),

        this, SLOT(StartProcessError(QProcess::ProcessError)));

    connect(process, SIGNAL(finished(int, QProcess::ExitStatus)),

        this, SLOT(onEngineDeath(int, QProcess::ExitStatus)));

    QStringList arguments = getArguments();

#ifdef QT_DEBUG

    // redirect everything written on stdout/stderr

    process->setProcessChannelMode(QProcess::ForwardedChannels);

#endif

    // If game config uses non-system locale, we set the environment

    // of the engine first

    if(m_usesCustomLanguage)

    {

        QProcessEnvironment env = QProcessEnvironment::systemEnvironment();

        QString hwengineLang = QLocale().name() + ".UTF8";

        qDebug("Setting hwengine environment: LANG=%s", qPrintable(hwengineLang));

        // TODO: Check if this is correct and works on all systems

        env.insert("LANG", QLocale().name() + ".UTF8");

        process->setProcessEnvironment(env);

    }

    qDebug("Starting hwengine ...");

    process->start(bindir->absolutePath() + "/hwengine", arguments);

#endif

    m_hasStarted = true;

}

void TCPBase::ClientDisconnect()

{

    onClientDisconnect();

    if(!simultaneousRun())

    {

#ifdef HWLIBRARY

        thread->quit();

        thread->wait();

#endif

        emit isReadyNow();

    }

    if(IPCSocket) {

      disconnect(IPCSocket, SIGNAL(readyRead()), this, SLOT(ClientRead()));

      IPCSocket->deleteLater();

      IPCSocket = NULL;

    }

    deleteLater();

}

void TCPBase::ClientRead()

{

    QByteArray read = IPCSocket->readAll();

    if(read.isEmpty()) return;

    readbuffer.append(read);

    onClientRead();

}

void TCPBase::StartProcessError(QProcess::ProcessError error)

{

    MessageDialog::ShowFatalMessage(tr("Unable to run engine at %1\nError code: %2").arg(bindir->absolutePath() + "/hwengine").arg(error));

    ClientDisconnect();

}

void TCPBase::onEngineDeath(int exitCode, QProcess::ExitStatus exitStatus)

{

    Q_UNUSED(exitStatus);

    if(!m_connected) { // yes, it is intended to be like this

      ClientDisconnect(); // need to do cleanup in case no connection occured,

      //if m_connected is true, it is done automatically in socket disconnect handler

    }

    // show error message if there was an error that was not an engine's

    // fatal error - because that one already sent a info via IPC

    if ((exitCode != HWENGINE_EXITCODE_OK) && (exitCode != HWENGINE_EXITCODE_FATAL))

    {

        // inform user that something bad happened

        MessageDialog::ShowFatalMessage(

            tr("The game engine died unexpectedly!\n"

            "(exit code %1)\n\n"

            "We are very sorry for the inconvenience :(\n\n"

            "If this keeps happening, please click the '%2' button in the main menu!")

            .arg(exitCode)

            .arg(QCoreApplication::translate("PageMain", "Feedback")));

    }

}

void TCPBase::tcpServerReady()

{

    if (!srvsList.isEmpty())

    {

        disconnect(srvsList.first(), SIGNAL(isReadyNow()), this, SLOT(tcpServerReady()));

        RealStart();

    }

    else

    {

        qDebug("tcpServerReady() called while srvsList was empty. Not starting TCP server");

    }

}

void TCPBase::Start(bool couldCancelPreviousRequest)

{

    if(srvsList.isEmpty())

    {

        srvsList.push_back(this);

        RealStart();

    }

    else

    {

        TCPBase * last = srvsList.last();

        if(couldCancelPreviousRequest

            && last->couldBeRemoved()

            && (last->isConnected() || !last->hasStarted())

            && (last->parent() == parent()))

        {

            srvsList.removeLast();

            delete last;

            Start(couldCancelPreviousRequest);

        } else

        {

            connect(last, SIGNAL(isReadyNow()), this, SLOT(tcpServerReady()));

            srvsList.push_back(this);

        }

    }

}

void TCPBase::onClientRead()

{

}

void TCPBase::onClientDisconnect()

{

}

void TCPBase::SendToClientFirst()

{

}

void TCPBase::SendIPC(const QByteArray & buf)

{

    if (buf.size() > MAXMSGCHARS) return;

    quint8 len = buf.size();

    RawSendIPC(QByteArray::fromRawData((char *)&len, 1) + buf);

}

void TCPBase::RawSendIPC(const QByteArray & buf)

{

    if (!IPCSocket)

    {

        toSendBuf += buf;

    }

    else

    {

        if (toSendBuf.size() > 0)

        {

            IPCSocket->write(toSendBuf);

            if(m_isDemoMode) demo.append(toSendBuf);

            toSendBuf.clear();

        }

        if(!buf.isEmpty())

        {

            IPCSocket->write(buf);

            if(m_isDemoMode) demo.append(buf);

        }

    }

}

bool TCPBase::couldBeRemoved()

{

    return false;

}

bool TCPBase::isConnected()

{

    return m_connected;

}

bool TCPBase::simultaneousRun()

{

    return false;

}

bool TCPBase::hasStarted()

{

    return m_hasStarted;

}