/***************************************************************************
**
** This file is part of Qt Creator
**
** Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).
**
** Contact:  Qt Software Information (qt-info@nokia.com)
**
** 
** Non-Open Source Usage  
** 
** Licensees may use this file in accordance with the Qt Beta Version
** License Agreement, Agreement version 2.2 provided with the Software or,
** alternatively, in accordance with the terms contained in a written
** agreement between you and Nokia.  
** 
** GNU General Public License Usage 
** 
** Alternatively, this file may be used under the terms of the GNU General
** Public License versions 2.0 or 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the packaging
** of this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
**
** http://www.fsf.org/licensing/licenses/info/GPLv2.html and
** http://www.gnu.org/copyleft/gpl.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt GPL Exception version
** 1.2, included in the file GPL_EXCEPTION.txt in this package.  
** 
***************************************************************************/

#include "synchronousprocess.h"

#include <QtCore/QDebug>
#include <QtCore/QTimer>
#include <QtCore/QEventLoop>
#include <QtCore/QTextCodec>

#include <QtGui/QApplication>

enum { debug = 0 };

enum { defaultMaxHangTimerCount = 10 };

namespace Core {
namespace Utils {

// ----------- SynchronousProcessResponse
SynchronousProcessResponse::SynchronousProcessResponse() :
   result(StartFailed),
   exitCode(-1)
{
}

void SynchronousProcessResponse::clear()
{
    result = StartFailed;
    exitCode = -1;
    stdOut.clear();
    stdErr.clear();
}

QWORKBENCH_UTILS_EXPORT QDebug operator<<(QDebug str, const SynchronousProcessResponse& r)
{
    QDebug nsp = str.nospace();
    nsp << "SynchronousProcessResponse: result=" << r.result << " ex=" << r.exitCode << '\n'
        << r.stdOut.size() << " bytes stdout, stderr=" << r.stdErr << '\n';
    return str;
}

// Data for one channel buffer (stderr/stdout)
struct ChannelBuffer {
    ChannelBuffer();
    void clearForRun();
    QByteArray linesRead();

    QByteArray data;
    bool firstData;
    bool bufferedSignalsEnabled;
    bool firstBuffer;
    int bufferPos;
};

ChannelBuffer::ChannelBuffer() :
    firstData(true),
    bufferedSignalsEnabled(false),
    firstBuffer(true),
    bufferPos(0)
{
}

void ChannelBuffer::clearForRun()
{
    firstData = true;
    firstBuffer = true;
    bufferPos = 0;
}

/* Check for complete lines read from the device and return them, moving the
 * buffer position. This is based on the assumption that '\n' is the new line
 * marker in any sane codec. */
QByteArray ChannelBuffer::linesRead()
{
    // Any new lines?
    const int lastLineIndex = data.lastIndexOf('\n');
    if (lastLineIndex == -1 || lastLineIndex <= bufferPos)
        return QByteArray();
    const int nextBufferPos = lastLineIndex + 1;
    const QByteArray lines = data.mid(bufferPos, nextBufferPos - bufferPos);
    bufferPos = nextBufferPos;
    return lines;
}

// ----------- SynchronousProcessPrivate
struct SynchronousProcessPrivate {
    SynchronousProcessPrivate();
    void clearForRun();

    QTextCodec *m_stdOutCodec;
    QProcess m_process;
    QTimer m_timer;
    QEventLoop m_eventLoop;
    SynchronousProcessResponse m_result;
    int m_hangTimerCount;
    int m_maxHangTimerCount;

    ChannelBuffer m_stdOut;
    ChannelBuffer m_stdErr;
};

SynchronousProcessPrivate::SynchronousProcessPrivate() :
    m_stdOutCodec(0),
    m_hangTimerCount(0),
    m_maxHangTimerCount(defaultMaxHangTimerCount)
{
}

void SynchronousProcessPrivate::clearForRun()
{
    m_hangTimerCount = 0;
    m_stdOut.clearForRun();
    m_stdErr.clearForRun();
    m_result.clear();
}

// ----------- SynchronousProcess
SynchronousProcess::SynchronousProcess() :
    m_d(new SynchronousProcessPrivate)
{
    m_d->m_timer.setInterval(1000);
    connect(&m_d->m_timer, SIGNAL(timeout()), this, SLOT(slotTimeout()));
    connect(&m_d->m_process, SIGNAL(finished(int,QProcess::ExitStatus)), this, SLOT(finished(int,QProcess::ExitStatus)));
    connect(&m_d->m_process, SIGNAL(error(QProcess::ProcessError)), this, SLOT(error(QProcess::ProcessError)));
    connect(&m_d->m_process, SIGNAL(readyReadStandardOutput()),
            this, SLOT(stdOutReady()));
    connect(&m_d->m_process, SIGNAL(readyReadStandardError()),
            this, SLOT(stdErrReady()));
}

SynchronousProcess::~SynchronousProcess()
{
    delete m_d;
}

void SynchronousProcess::setTimeout(int timeoutMS)
{
    m_d->m_maxHangTimerCount = qMax(2, timeoutMS / 1000);
}

int SynchronousProcess::timeout() const
{
    return 1000 * m_d->m_maxHangTimerCount;
}

void SynchronousProcess::setStdOutCodec(QTextCodec *c)
{
    m_d->m_stdOutCodec = c;
}

QTextCodec *SynchronousProcess::stdOutCodec() const
{
    return m_d->m_stdOutCodec;
}

bool SynchronousProcess::stdOutBufferedSignalsEnabled() const
{
    return m_d->m_stdOut.bufferedSignalsEnabled;
}

void SynchronousProcess::setStdOutBufferedSignalsEnabled(bool v)
{
    m_d->m_stdOut.bufferedSignalsEnabled = v;
}

bool SynchronousProcess::stdErrBufferedSignalsEnabled() const
{
    return m_d->m_stdErr.bufferedSignalsEnabled;
}

void SynchronousProcess::setStdErrBufferedSignalsEnabled(bool v)
{
    m_d->m_stdErr.bufferedSignalsEnabled = v;
}

QStringList SynchronousProcess::environment() const
{
    return m_d->m_process.environment();
}

void SynchronousProcess::setEnvironment(const QStringList &e)
{
    m_d->m_process.setEnvironment(e);
}

SynchronousProcessResponse SynchronousProcess::run(const QString &binary,
                                                 const QStringList &args)
{
    if (debug)
        qDebug() << '>' << Q_FUNC_INFO << binary << args;

    m_d->clearForRun();
    m_d->m_timer.start();

    QApplication::setOverrideCursor(Qt::WaitCursor);

    m_d->m_process.start(binary, args, QIODevice::ReadOnly);
    m_d->m_eventLoop.exec(QEventLoop::ExcludeUserInputEvents);
    if (m_d->m_result.result == SynchronousProcessResponse::Finished || m_d->m_result.result == SynchronousProcessResponse::FinishedError) {
        processStdOut(false);
        processStdErr(false);
    }

    m_d->m_result.stdOut = convertStdOut(m_d->m_stdOut.data);
    m_d->m_result.stdErr = convertStdErr(m_d->m_stdErr.data);

    m_d->m_timer.stop();
    QApplication::restoreOverrideCursor();

    if (debug)
        qDebug() << '<' << Q_FUNC_INFO << binary << m_d->m_result;
    return  m_d->m_result;
}

void SynchronousProcess::slotTimeout()
{
    if (++m_d->m_hangTimerCount > m_d->m_maxHangTimerCount) {
        m_d->m_process.kill();
        m_d->m_result.result = SynchronousProcessResponse::Hang;
    }

    if (debug)
        qDebug() << Q_FUNC_INFO << m_d->m_hangTimerCount;
}

void SynchronousProcess::finished(int exitCode, QProcess::ExitStatus e)
{
    if (debug)
        qDebug() << Q_FUNC_INFO << exitCode << e;
    m_d->m_hangTimerCount = 0;
    switch (e) {
    case QProcess::NormalExit:
        m_d->m_result.result = exitCode ? SynchronousProcessResponse::FinishedError : SynchronousProcessResponse::Finished;
        m_d->m_result.exitCode = exitCode;
        break;
    case QProcess::CrashExit:
        m_d->m_result.result = SynchronousProcessResponse::TerminatedAbnormally;
        m_d->m_result.exitCode = -1;
        break;
    }
    m_d->m_eventLoop.quit();
}

void SynchronousProcess::error(QProcess::ProcessError e)
{
    m_d->m_hangTimerCount = 0;
    if (debug)
        qDebug() << Q_FUNC_INFO << e;
    m_d->m_result.result = SynchronousProcessResponse::StartFailed;
    m_d->m_eventLoop.quit();
}

void SynchronousProcess::stdOutReady()
{
    m_d->m_hangTimerCount = 0;
    processStdOut(true);
}

void SynchronousProcess::stdErrReady()
{
    m_d->m_hangTimerCount = 0;
    processStdErr(true);
}

QString SynchronousProcess::convertStdErr(const QByteArray &ba)
{
    return QString::fromLocal8Bit(ba).remove(QLatin1Char('\r'));
}

QString SynchronousProcess::convertStdOut(const QByteArray &ba) const
{
    QString stdOut = m_d->m_stdOutCodec ? m_d->m_stdOutCodec->toUnicode(ba) : QString::fromLocal8Bit(ba);
    return stdOut.remove(QLatin1Char('\r'));
}

void SynchronousProcess::processStdOut(bool emitSignals)
{
    // Handle binary data
    const QByteArray ba = m_d->m_process.readAllStandardOutput();
    if (debug > 1)
        qDebug() << Q_FUNC_INFO << emitSignals << ba;
    if (!ba.isEmpty()) {
        m_d->m_stdOut.data += ba;
        if (emitSignals) {
            // Emit binary signals
            emit stdOut(ba, m_d->m_stdOut.firstData);
            m_d->m_stdOut.firstData = false;
            // Buffered. Emit complete lines?
            if (m_d->m_stdOut.bufferedSignalsEnabled) {
                const QByteArray lines = m_d->m_stdOut.linesRead();
                if (!lines.isEmpty()) {
                    emit stdOutBuffered(convertStdOut(lines), m_d->m_stdOut.firstBuffer);
                    m_d->m_stdOut.firstBuffer = false;
                }
            }
        }
    }
}

void SynchronousProcess::processStdErr(bool emitSignals)
{
    // Handle binary data
    const QByteArray ba = m_d->m_process.readAllStandardError();
    if (debug > 1)
        qDebug() << Q_FUNC_INFO << emitSignals << ba;
    if (!ba.isEmpty()) {
        m_d->m_stdErr.data += ba;
        if (emitSignals) {
            // Emit binary signals
            emit stdErr(ba, m_d->m_stdErr.firstData);
            m_d->m_stdErr.firstData = false;
            if (m_d->m_stdErr.bufferedSignalsEnabled) {
                // Buffered. Emit complete lines?
                const QByteArray lines = m_d->m_stdErr.linesRead();
                if (!lines.isEmpty()) {
                    emit stdErrBuffered(convertStdErr(lines), m_d->m_stdErr.firstBuffer);
                    m_d->m_stdErr.firstBuffer = false;
                }
            }
        }
    }
}

} // namespace Utils
} // namespace Core