/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the test suite of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL-EXCEPT$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#ifdef QT_GUI_LIB
#  include <QtGui/QGuiApplication>
#  define tst_QEventDispatcher tst_QGuiEventDispatcher
#else
#  include <QtCore/QCoreApplication>
#endif
#include <QtTest/QtTest>

enum {
    PreciseTimerInterval    =   10,
    CoarseTimerInterval     =  200,
    VeryCoarseTimerInterval = 1000
};

class tst_QEventDispatcher : public QObject
{
    Q_OBJECT

    QAbstractEventDispatcher *eventDispatcher;
    int receivedEventType;
    int timerIdFromEvent;

protected:
    bool event(QEvent *e);

public:
    inline tst_QEventDispatcher()
        : QObject(),
          eventDispatcher(QAbstractEventDispatcher::instance(thread())),
          receivedEventType(-1),
          timerIdFromEvent(-1)
    { }

private slots:
    void initTestCase();
    void registerTimer();
    /* void registerSocketNotifier(); */ // Not implemented here, see tst_QSocketNotifier instead
    /* void registerEventNotifiier(); */ // Not implemented here, see tst_QWinEventNotifier instead
    void sendPostedEvents_data();
    void sendPostedEvents();
    void processEventsOnlySendsQueuedEvents();
};

bool tst_QEventDispatcher::event(QEvent *e)
{
    switch (receivedEventType = e->type()) {
    case QEvent::Timer:
    {
        timerIdFromEvent = static_cast<QTimerEvent *>(e)->timerId();
        return true;
    }
    default:
        break;
    }
    return QObject::event(e);
}

// drain the system event queue after the test starts to avoid destabilizing the test functions
void tst_QEventDispatcher::initTestCase()
{
    QElapsedTimer elapsedTimer;
    elapsedTimer.start();
    while (!elapsedTimer.hasExpired(CoarseTimerInterval) && eventDispatcher->processEvents(QEventLoop::AllEvents)) {
            ;
    }
}

class TimerManager {
    Q_DISABLE_COPY(TimerManager)

public:
    TimerManager(QAbstractEventDispatcher *eventDispatcher, QObject *parent)
        : m_eventDispatcher(eventDispatcher), m_parent(parent)
    {
    }

    ~TimerManager()
    {
        if (!registeredTimers().isEmpty())
            m_eventDispatcher->unregisterTimers(m_parent);
    }

    TimerManager(TimerManager &&) = delete;
    TimerManager &operator=(TimerManager &&) = delete;

    int preciseTimerId() const { return m_preciseTimerId; }
    int coarseTimerId() const { return m_coarseTimerId; }
    int veryCoarseTimerId() const { return m_veryCoarseTimerId; }

    bool foundPrecise() const { return m_preciseTimerId > 0; }
    bool foundCoarse() const { return m_coarseTimerId > 0; }
    bool foundVeryCoarse() const { return m_veryCoarseTimerId > 0; }

    QList<QAbstractEventDispatcher::TimerInfo> registeredTimers() const
    {
        return m_eventDispatcher->registeredTimers(m_parent);
    }

    void registerAll()
    {
        // start 3 timers, each with the different timer types and different intervals
        m_preciseTimerId = m_eventDispatcher->registerTimer(
                    PreciseTimerInterval, Qt::PreciseTimer, m_parent);
        m_coarseTimerId = m_eventDispatcher->registerTimer(
                    CoarseTimerInterval, Qt::CoarseTimer, m_parent);
        m_veryCoarseTimerId = m_eventDispatcher->registerTimer(
                    VeryCoarseTimerInterval, Qt::VeryCoarseTimer, m_parent);
        QVERIFY(m_preciseTimerId > 0);
        QVERIFY(m_coarseTimerId > 0);
        QVERIFY(m_veryCoarseTimerId > 0);
        findTimers();
    }

    void unregister(int timerId)
    {
        m_eventDispatcher->unregisterTimer(timerId);
        findTimers();
    }

    void unregisterAll()
    {
        m_eventDispatcher->unregisterTimers(m_parent);
        findTimers();
    }

private:
    void findTimers()
    {
        bool foundPrecise = false;
        bool foundCoarse = false;
        bool foundVeryCoarse = false;
        const QList<QAbstractEventDispatcher::TimerInfo> timers = registeredTimers();
        for (int i = 0; i < timers.count(); ++i) {
            const QAbstractEventDispatcher::TimerInfo &timerInfo = timers.at(i);
            if (timerInfo.timerId == m_preciseTimerId) {
                QCOMPARE(timerInfo.interval, int(PreciseTimerInterval));
                QCOMPARE(timerInfo.timerType, Qt::PreciseTimer);
                foundPrecise = true;
            } else if (timerInfo.timerId == m_coarseTimerId) {
                QCOMPARE(timerInfo.interval, int(CoarseTimerInterval));
                QCOMPARE(timerInfo.timerType, Qt::CoarseTimer);
                foundCoarse = true;
            } else if (timerInfo.timerId == m_veryCoarseTimerId) {
                QCOMPARE(timerInfo.interval, int(VeryCoarseTimerInterval));
                QCOMPARE(timerInfo.timerType, Qt::VeryCoarseTimer);
                foundVeryCoarse = true;
            }
        }
        if (!foundPrecise)
            m_preciseTimerId = -1;
        if (!foundCoarse)
            m_coarseTimerId = -1;
        if (!foundVeryCoarse)
            m_veryCoarseTimerId = -1;
    }

    QAbstractEventDispatcher *m_eventDispatcher = nullptr;

    int m_preciseTimerId = -1;
    int m_coarseTimerId = -1;
    int m_veryCoarseTimerId = -1;

    QObject *m_parent = nullptr;
};

// test that the eventDispatcher's timer implementation is complete and working
void tst_QEventDispatcher::registerTimer()
{
    TimerManager timers(eventDispatcher, this);
    timers.registerAll();
    if (QTest::currentTestFailed())
        return;

    // check that all 3 are present in the eventDispatcher's registeredTimer() list
    QCOMPARE(timers.registeredTimers().count(), 3);
    QVERIFY(timers.foundPrecise());
    QVERIFY(timers.foundCoarse());
    QVERIFY(timers.foundVeryCoarse());

    // process events, waiting for the next event... this should only fire the precise timer
    receivedEventType = -1;
    timerIdFromEvent = -1;
    QTRY_COMPARE_WITH_TIMEOUT(receivedEventType, int(QEvent::Timer), PreciseTimerInterval * 2);
    QCOMPARE(timerIdFromEvent, timers.preciseTimerId());
    // now unregister it and make sure it's gone
    timers.unregister(timers.preciseTimerId());
    if (QTest::currentTestFailed())
        return;
    QCOMPARE(timers.registeredTimers().count(), 2);
    QVERIFY(!timers.foundPrecise());
    QVERIFY(timers.foundCoarse());
    QVERIFY(timers.foundVeryCoarse());

    // do the same again for the coarse timer
    receivedEventType = -1;
    timerIdFromEvent = -1;
    QTRY_COMPARE_WITH_TIMEOUT(receivedEventType, int(QEvent::Timer), CoarseTimerInterval * 2);
    QCOMPARE(timerIdFromEvent, timers.coarseTimerId());
    // now unregister it and make sure it's gone
    timers.unregister(timers.coarseTimerId());
    if (QTest::currentTestFailed())
        return;
    QCOMPARE(timers.registeredTimers().count(), 1);
    QVERIFY(!timers.foundPrecise());
    QVERIFY(!timers.foundCoarse());
    QVERIFY(timers.foundVeryCoarse());

    // not going to wait for the VeryCoarseTimer, would take too long, just unregister it
    timers.unregisterAll();
    if (QTest::currentTestFailed())
        return;
    QVERIFY(timers.registeredTimers().isEmpty());
}

void tst_QEventDispatcher::sendPostedEvents_data()
{
    QTest::addColumn<int>("processEventsFlagsInt");

    QTest::newRow("WaitForMoreEvents") << int(QEventLoop::WaitForMoreEvents);
    QTest::newRow("AllEvents") << int(QEventLoop::AllEvents);
}

// test that the eventDispatcher sends posted events correctly
void tst_QEventDispatcher::sendPostedEvents()
{
    QFETCH(int, processEventsFlagsInt);
    QEventLoop::ProcessEventsFlags processEventsFlags = QEventLoop::ProcessEventsFlags(processEventsFlagsInt);

    QElapsedTimer elapsedTimer;
    elapsedTimer.start();
    while (!elapsedTimer.hasExpired(200)) {
        receivedEventType = -1;
        QCoreApplication::postEvent(this, new QEvent(QEvent::User));

        // event shouldn't be delivered as a result of posting
        QCOMPARE(receivedEventType, -1);

        // since there is a pending posted event, this should not actually block, it should send the posted event and return
        QVERIFY(eventDispatcher->processEvents(processEventsFlags));
        // event shouldn't be delivered as a result of posting
        QCOMPARE(receivedEventType, int(QEvent::User));
    }
}

class ProcessEventsOnlySendsQueuedEvents : public QObject
{
    Q_OBJECT
public:
    int eventsReceived;

    inline ProcessEventsOnlySendsQueuedEvents() : eventsReceived(0) {}

    bool event(QEvent *event)
    {
        ++eventsReceived;

        if (event->type() == QEvent::User)
             QCoreApplication::postEvent(this, new QEvent(QEvent::Type(QEvent::User + 1)));

        return QObject::event(event);
    }
public slots:
    void timerFired()
    {
        QCoreApplication::postEvent(this, new QEvent(QEvent::Type(QEvent::User + 1)));
    }
};

void tst_QEventDispatcher::processEventsOnlySendsQueuedEvents()
{
    ProcessEventsOnlySendsQueuedEvents object;

    // Posted events during event processing should be handled on
    // the next processEvents iteration.
    QCoreApplication::postEvent(&object, new QEvent(QEvent::User));
    QCoreApplication::processEvents();
    QCOMPARE(object.eventsReceived, 1);
    QCoreApplication::processEvents();
    QCOMPARE(object.eventsReceived, 2);

    // The same goes for posted events during timer processing
    QTimer::singleShot(0, &object, SLOT(timerFired()));
    QCoreApplication::processEvents();
    QCOMPARE(object.eventsReceived, 3);
    QCoreApplication::processEvents();
    QCOMPARE(object.eventsReceived, 4);
}

QTEST_MAIN(tst_QEventDispatcher)
#include "tst_qeventdispatcher.moc"