/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
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** This file is part of the QtGui module of the Qt Toolkit.
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** 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
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** following information to ensure the GNU Lesser General Public License
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****************************************************************************/

#include "qcfsocketnotifier_p.h"
#include <QtGui/qguiapplication.h>
#include <QtCore/qsocketnotifier.h>
#include <QtCore/qthread.h>


/**************************************************************************
    Socket Notifiers
 *************************************************************************/
void qt_mac_socket_callback(CFSocketRef s, CFSocketCallBackType callbackType, CFDataRef,
                            const void *, void *info)
{

    QCFSocketNotifier *cfSocketNotifier = static_cast<QCFSocketNotifier *>(info);
    int nativeSocket = CFSocketGetNative(s);
    MacSocketInfo *socketInfo = cfSocketNotifier->macSockets.value(nativeSocket);
    QEvent notifierEvent(QEvent::SockAct);

    // There is a race condition that happen where we disable the notifier and
    // the kernel still has a notification to pass on. We then get this
    // notification after we've successfully disabled the CFSocket, but our Qt
    // notifier is now gone. The upshot is we have to check the notifier
    // every time.
    if (callbackType == kCFSocketReadCallBack) {
        if (socketInfo->readNotifier)
            QGuiApplication::sendEvent(socketInfo->readNotifier, &notifierEvent);
    } else if (callbackType == kCFSocketWriteCallBack) {
        if (socketInfo->writeNotifier)
            QGuiApplication::sendEvent(socketInfo->writeNotifier, &notifierEvent);
    }

    if (cfSocketNotifier->maybeCancelWaitForMoreEvents)
        cfSocketNotifier->maybeCancelWaitForMoreEvents(cfSocketNotifier->eventDispatcher);
}

/*
    Adds a loop source for the given socket to the current run loop.
*/
CFRunLoopSourceRef qt_mac_add_socket_to_runloop(const CFSocketRef socket)
{
    CFRunLoopSourceRef loopSource = CFSocketCreateRunLoopSource(kCFAllocatorDefault, socket, 0);
    if (!loopSource)
        return 0;

    CFRunLoopAddSource(CFRunLoopGetMain(), loopSource, kCFRunLoopCommonModes);
    return loopSource;
}

/*
    Removes the loop source for the given socket from the current run loop.
*/
void qt_mac_remove_socket_from_runloop(const CFSocketRef socket, CFRunLoopSourceRef runloop)
{
    Q_ASSERT(runloop);
    CFRunLoopRemoveSource(CFRunLoopGetMain(), runloop, kCFRunLoopCommonModes);
    CFSocketDisableCallBacks(socket, kCFSocketReadCallBack);
    CFSocketDisableCallBacks(socket, kCFSocketWriteCallBack);
    CFRunLoopSourceInvalidate(runloop);
}

QCFSocketNotifier::QCFSocketNotifier()
:eventDispatcher(0)
, maybeCancelWaitForMoreEvents(0)
{

}

QCFSocketNotifier::~QCFSocketNotifier()
{

}

void QCFSocketNotifier::setHostEventDispatcher(QAbstractEventDispatcher *hostEventDispacher)
{
    eventDispatcher = hostEventDispacher;
}

void QCFSocketNotifier::setMaybeCancelWaitForMoreEventsCallback(MaybeCancelWaitForMoreEventsFn callBack)
{
    maybeCancelWaitForMoreEvents = callBack;
}

void QCFSocketNotifier::registerSocketNotifier(QSocketNotifier *notifier)
{
    Q_ASSERT(notifier);
    int nativeSocket = notifier->socket();
    int type = notifier->type();
#ifndef QT_NO_DEBUG
    if (nativeSocket < 0 || nativeSocket > FD_SETSIZE) {
        qWarning("QSocketNotifier: Internal error");
        return;
    } else if (notifier->thread() != eventDispatcher->thread()
               || eventDispatcher->thread() != QThread::currentThread()) {
        qWarning("QSocketNotifier: socket notifiers cannot be enabled from another thread");
        return;
    }
#endif

    if (type == QSocketNotifier::Exception) {
        qWarning("QSocketNotifier::Exception is not supported on iOS");
        return;
    }

    // Check if we have a CFSocket for the native socket, create one if not.
    MacSocketInfo *socketInfo = macSockets.value(nativeSocket);
    if (!socketInfo) {
        socketInfo = new MacSocketInfo();

        // Create CFSocket, specify that we want both read and write callbacks (the callbacks
        // are enabled/disabled later on).
        const int callbackTypes = kCFSocketReadCallBack | kCFSocketWriteCallBack;
        CFSocketContext context = {0, this, 0, 0, 0};
        socketInfo->socket = CFSocketCreateWithNative(kCFAllocatorDefault, nativeSocket, callbackTypes, qt_mac_socket_callback, &context);
        if (CFSocketIsValid(socketInfo->socket) == false) {
            qWarning("QEventDispatcherMac::registerSocketNotifier: Failed to create CFSocket");
            return;
        }

        CFOptionFlags flags = CFSocketGetSocketFlags(socketInfo->socket);
        flags |= kCFSocketAutomaticallyReenableWriteCallBack; //QSocketNotifier stays enabled after a write
        flags &= ~kCFSocketCloseOnInvalidate; //QSocketNotifier doesn't close the socket upon destruction/invalidation
        CFSocketSetSocketFlags(socketInfo->socket, flags);

        // Add CFSocket to runloop.
        if (!(socketInfo->runloop = qt_mac_add_socket_to_runloop(socketInfo->socket))) {
            qWarning("QEventDispatcherMac::registerSocketNotifier: Failed to add CFSocket to runloop");
            CFSocketInvalidate(socketInfo->socket);
            CFRelease(socketInfo->socket);
            return;
        }

        // Disable both callback types by default. This must be done after
        // we add the CFSocket to the runloop, or else these calls will have
        // no effect.
        CFSocketDisableCallBacks(socketInfo->socket, kCFSocketReadCallBack);
        CFSocketDisableCallBacks(socketInfo->socket, kCFSocketWriteCallBack);

        macSockets.insert(nativeSocket, socketInfo);
    }

    // Increment read/write counters and select enable callbacks if necessary.
    if (type == QSocketNotifier::Read) {
        Q_ASSERT(socketInfo->readNotifier == 0);
        socketInfo->readNotifier = notifier;
        CFSocketEnableCallBacks(socketInfo->socket, kCFSocketReadCallBack);
    } else if (type == QSocketNotifier::Write) {
        Q_ASSERT(socketInfo->writeNotifier == 0);
        socketInfo->writeNotifier = notifier;
        CFSocketEnableCallBacks(socketInfo->socket, kCFSocketWriteCallBack);
    }
}

void QCFSocketNotifier::unregisterSocketNotifier(QSocketNotifier *notifier)
{
    Q_ASSERT(notifier);
    int nativeSocket = notifier->socket();
    int type = notifier->type();
#ifndef QT_NO_DEBUG
    if (nativeSocket < 0 || nativeSocket > FD_SETSIZE) {
        qWarning("QSocketNotifier: Internal error");
        return;
    } else if (notifier->thread() != eventDispatcher->thread() || eventDispatcher->thread() != QThread::currentThread()) {
        qWarning("QSocketNotifier: socket notifiers cannot be disabled from another thread");
        return;
    }
#endif

    if (type == QSocketNotifier::Exception) {
        qWarning("QSocketNotifier::Exception is not supported on iOS");
        return;
    }
    MacSocketInfo *socketInfo = macSockets.value(nativeSocket);
    if (!socketInfo) {
        qWarning("QEventDispatcherMac::unregisterSocketNotifier: Tried to unregister a not registered notifier");
        return;
    }

    // Decrement read/write counters and disable callbacks if necessary.
    if (type == QSocketNotifier::Read) {
        Q_ASSERT(notifier == socketInfo->readNotifier);
        socketInfo->readNotifier = 0;
        CFSocketDisableCallBacks(socketInfo->socket, kCFSocketReadCallBack);
    } else if (type == QSocketNotifier::Write) {
        Q_ASSERT(notifier == socketInfo->writeNotifier);
        socketInfo->writeNotifier = 0;
        CFSocketDisableCallBacks(socketInfo->socket, kCFSocketWriteCallBack);
    }

    // Remove CFSocket from runloop if this was the last QSocketNotifier.
    if (socketInfo->readNotifier == 0 && socketInfo->writeNotifier == 0) {
        if (CFSocketIsValid(socketInfo->socket))
            qt_mac_remove_socket_from_runloop(socketInfo->socket, socketInfo->runloop);
        CFRunLoopSourceInvalidate(socketInfo->runloop);
        CFRelease(socketInfo->runloop);
        CFSocketInvalidate(socketInfo->socket);
        CFRelease(socketInfo->socket);
        delete socketInfo;
        macSockets.remove(nativeSocket);
    }
}

void QCFSocketNotifier::removeSocketNotifiers()
{
    // Remove CFSockets from the runloop.
    for (MacSocketHash::ConstIterator it = macSockets.constBegin(); it != macSockets.constEnd(); ++it) {
        MacSocketInfo *socketInfo = (*it);
        if (CFSocketIsValid(socketInfo->socket)) {
            qt_mac_remove_socket_from_runloop(socketInfo->socket, socketInfo->runloop);
            CFRunLoopSourceInvalidate(socketInfo->runloop);
            CFRelease(socketInfo->runloop);
            CFSocketInvalidate(socketInfo->socket);
            CFRelease(socketInfo->socket);
        }
    }
}