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**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
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** This file is part of Qt Creator.
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** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
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** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file.  Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
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****************************************************************************/

#include "connectionclient.h"

#include <QProcess>
#include <QThread>
#include <QCoreApplication>

#include "cmbregistertranslationunitsforcodecompletioncommand.h"
#include "cmbunregistertranslationunitsforcodecompletioncommand.h"
#include "cmbcompletecodecommand.h"

namespace CodeModelBackEnd {

namespace {
QString currentProcessId()
{
    return QString::number(QCoreApplication::applicationPid());
}

QString connectionName()
{
    return QStringLiteral("CodeModelBackEnd-") + currentProcessId();
}
}

ConnectionClient::ConnectionClient(IpcClientInterface *client)
    : serverProxy_(client, &localSocket)
{
    processAliveTimer.setInterval(10000);

    connect(&processAliveTimer, &QTimer::timeout, this, &ConnectionClient::restartProcess);
    connect(&localSocket,
            static_cast<void (QLocalSocket::*)(QLocalSocket::LocalSocketError)>(&QLocalSocket::error),
            this,
            &ConnectionClient::printLocalSocketError);
}

ConnectionClient::~ConnectionClient()
{
    finishProcess();
}

bool ConnectionClient::connectToServer()
{
    startProcess();
    resetProcessAliveTimer();
    const bool isConnected = connectToLocalSocket();

    return isConnected;
}

bool ConnectionClient::disconnectFromServer()
{
    localSocket.disconnectFromServer();
    if (localSocket.state() != QLocalSocket::UnconnectedState)
        return localSocket.waitForDisconnected();

    return true;
}

bool ConnectionClient::isConnected() const
{
    return localSocket.state() == QLocalSocket::ConnectedState;
}

void ConnectionClient::sendEndCommand()
{
    serverProxy_.end();
    localSocket.flush();
}

void ConnectionClient::resetProcessAliveTimer()
{
    processAliveTimer.start();
}

void ConnectionClient::setProcessAliveTimerInterval(int processTimerInterval)
{
    processAliveTimer.setInterval(processTimerInterval);
}

void ConnectionClient::startProcess()
{
    if (!isProcessIsRunning()) {
        connectProcessFinished();
        connectStandardOutputAndError();
        process()->start(processPath(), {connectionName()});
        process()->waitForStarted();
        processAliveTimer.start();
    }
}

void ConnectionClient::restartProcess()
{
    finishProcess();
    startProcess();

    connectToServer();

    emit processRestarted();
}

bool ConnectionClient::connectToLocalSocket()
{
    QThread::msleep(30);

    for (int counter = 0; counter < 1000; counter++) {
        localSocket.connectToServer(connectionName());
        bool isConnected = localSocket.waitForConnected(20);

        if (isConnected)
            return isConnected;
        else
            QThread::msleep(30);
    }

    qDebug() << "Cannot connect:" <<localSocket.errorString();

    return false;
}

void ConnectionClient::endProcess()
{
    if (isProcessIsRunning()) {
        sendEndCommand();
        process()->waitForFinished();
    }
}

void ConnectionClient::terminateProcess()
{
#ifndef Q_OS_WIN32
    if (isProcessIsRunning()) {
        process()->terminate();
        process()->waitForFinished();
    }
#endif
}

void ConnectionClient::killProcess()
{
    if (isProcessIsRunning()) {
        process()->kill();
        process()->waitForFinished();
    }
}

void ConnectionClient::printLocalSocketError(QLocalSocket::LocalSocketError /*socketError*/)
{
    qWarning() << "ClangCodeModel ConnectionClient LocalSocket Error:" << localSocket.errorString();
}

void ConnectionClient::printStandardOutput()
{
    qWarning() << "CodeModelBackEnd:" << process_->readAllStandardOutput();
}

void ConnectionClient::printStandardError()
{
    qWarning() << "CodeModelBackEnd Error:" << process_->readAllStandardError();
}

void ConnectionClient::finishProcess()
{
    processAliveTimer.stop();

    disconnectProcessFinished();
    endProcess();
    disconnectFromServer();
    terminateProcess();
    killProcess();

    process_.reset();

    serverProxy_.resetCounter();
}

bool ConnectionClient::waitForEcho()
{
    return localSocket.waitForReadyRead();
}

IpcServerProxy &ConnectionClient::serverProxy()
{
    return serverProxy_;
}

QProcess *ConnectionClient::processForTestOnly() const
{
    return process_.get();
}

bool ConnectionClient::isProcessIsRunning() const
{
    return process_ && process_->state() == QProcess::Running;
}

QProcess *ConnectionClient::process() const
{
    if (!process_)
        process_.reset(new QProcess);

    return process_.get();
}

void ConnectionClient::connectProcessFinished() const
{
    connect(process(),
            static_cast<void (QProcess::*)(int, QProcess::ExitStatus)>(&QProcess::finished),
            this,
            &ConnectionClient::restartProcess);

}

void ConnectionClient::disconnectProcessFinished() const
{
    if (process_) {
        disconnect(process_.get(),
                   static_cast<void (QProcess::*)(int, QProcess::ExitStatus)>(&QProcess::finished),
                   this,
                   &ConnectionClient::restartProcess);
    }
}

void ConnectionClient::connectStandardOutputAndError() const
{
    connect(process(), &QProcess::readyReadStandardOutput, this, &ConnectionClient::printStandardOutput);
    connect(process(), &QProcess::readyReadStandardError, this, &ConnectionClient::printStandardError);
}

const QString &ConnectionClient::processPath() const
{
    return processPath_;
}

void ConnectionClient::setProcessPath(const QString &processPath)
{
    processPath_ = processPath;
}

} // namespace CodeModelBackEnd