/* ***** BEGIN LICENSE BLOCK *****
 * This file is part of Natron <https://natrongithub.github.io/>,
 * (C) 2018-2021 The Natron developers
 * (C) 2013-2018 INRIA and Alexandre Gauthier-Foichat
 *
 * Natron 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Natron 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 Natron.  If not, see <http://www.gnu.org/licenses/gpl-2.0.html>
 * ***** END LICENSE BLOCK ***** */

// ***** BEGIN PYTHON BLOCK *****
// from <https://docs.python.org/3/c-api/intro.html#include-files>:
// "Since Python may define some pre-processor definitions which affect the standard headers on some systems, you must include Python.h before any standard headers are included."
#include <Python.h>
// ***** END PYTHON BLOCK *****

#include "ExistenceCheckThread.h"


#include <cassert>
#include <stdexcept>
#include <iostream>

#include <QtNetwork/QLocalSocket>
#include <QtCore/QMutex>
#include <QtCore/QWaitCondition>
#include <QtCore/QDebug>

#ifdef DEBUG
#include "Global/FloatingPointExceptions.h"
#endif
#include "Engine/AppManager.h"

//This will check every X ms whether the crash reporter process still exist when
//Natron was spawned from the crash reporter process
#define NATRON_BREAKPAD_CHECK_FOR_CRASH_REPORTER_EXISTENCE_MS 2000

//After this time, we consider that the crash reporter is dead
#define NATRON_BREAKPAD_WAIT_FOR_CRASH_REPORTER_ACK_MS 5000

NATRON_NAMESPACE_ENTER

struct ExistenceCheckerThreadPrivate
{
    boost::shared_ptr<QLocalSocket> socket;
    QString comServerPipePath;
    QString checkMessage;
    QString acknowledgementMessage;
    mutable QMutex mustQuitMutex;
    bool mustQuit;
    QWaitCondition mustQuitCond;

    ExistenceCheckerThreadPrivate(const QString& checkMessage,
                                  const QString& acknowledgementMessage,
                                  const QString &comServerPipePath)
        : socket()
        , comServerPipePath(comServerPipePath)
        , checkMessage(checkMessage)
        , acknowledgementMessage(acknowledgementMessage)
        , mustQuitMutex()
        , mustQuit(false)
        , mustQuitCond()
    {
    }
};

ExistenceCheckerThread::ExistenceCheckerThread(const QString& checkMessage,
                                               const QString& acknowledgementMessage,
                                               const QString &comServerPipePath)
    : QThread()
    , _imp( new ExistenceCheckerThreadPrivate(checkMessage, acknowledgementMessage, comServerPipePath) )
{
    setObjectName( QString::fromUtf8("CrashReporterAliveThread") );
}

ExistenceCheckerThread::~ExistenceCheckerThread()
{
}

void
ExistenceCheckerThread::quitThread()
{
    if ( !isRunning() ) {
        return;
    }
    {
        QMutexLocker k(&_imp->mustQuitMutex);
        assert(!_imp->mustQuit);
        _imp->mustQuit = true;
        while (_imp->mustQuit) {
            _imp->mustQuitCond.wait(k.mutex());
        }
    }
    wait();
}

void
ExistenceCheckerThread::run()
{
#ifdef DEBUG
    boost_adaptbx::floating_point::exception_trapping trap(boost_adaptbx::floating_point::exception_trapping::division_by_zero |
                                                           boost_adaptbx::floating_point::exception_trapping::invalid |
                                                           boost_adaptbx::floating_point::exception_trapping::overflow);
#endif
    _imp->socket.reset( new QLocalSocket() );
    _imp->socket->connectToServer(_imp->comServerPipePath, QLocalSocket::ReadWrite);

    if ( !_imp->socket->waitForConnected() ) {
        std::cerr << "Failed to connect local socket to " << _imp->comServerPipePath.toStdString() << std::endl;

        return;
    }

    for (;; ) {
        {
            QMutexLocker k(&_imp->mustQuitMutex);
            if (_imp->mustQuit) {
                _imp->mustQuit = false;
                _imp->mustQuitCond.wakeOne();

                return;
            }
        }


        //Sleep until we need to check again
        msleep(NATRON_BREAKPAD_CHECK_FOR_CRASH_REPORTER_EXISTENCE_MS);


        qint64 writeOK;
        {
            QString tosend(_imp->checkMessage);
            tosend.push_back( QChar::fromLatin1('\n') );
            writeOK = _imp->socket->write( tosend.toStdString().c_str() );
        }
        if (writeOK >= 0) {
            _imp->socket->flush();

            bool receivedAcknowledgement = false;
            while ( _imp->socket->waitForReadyRead(NATRON_BREAKPAD_WAIT_FOR_CRASH_REPORTER_ACK_MS) ) {
                //we received something, if it's not the ackknowledgement packet, recheck
                QString str = QString::fromUtf8( _imp->socket->readLine() );
                while ( str.endsWith( QChar::fromLatin1('\n') ) ) {
                    str.chop(1);
                }
                if (str == _imp->acknowledgementMessage) {
                    receivedAcknowledgement = true;
                    break;
                }
            }

            if (!receivedAcknowledgement) {
                std::cerr << tr("Crash reporter process does not seem to be responding anymore. This pipe %1 might be used somewhere else.").arg(_imp->comServerPipePath).toStdString() << std::endl;
                /*
                   We did not receive the acknowledgement, hence quit
                 */
                Q_EMIT otherProcessUnreachable();

                return;
            }
        }
    } // for(;;)
} // ExistenceCheckerThread::run

NATRON_NAMESPACE_EXIT

NATRON_NAMESPACE_USING
#include "moc_ExistenceCheckThread.cpp"

