/****************************************************************************

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtDBus module of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at qt-info@nokia.com.

**

**

**

**

**

**

**

**

** $QT_END_LICENSE$

**

****************************************************************************/

#include "qdbuspendingcall.h"

#include "qdbuspendingcall_p.h"

#include "qdbusconnection_p.h"

#include "qdbusmetatype_p.h"

#include "qcoreapplication.h"

#include "qcoreevent.h"

#include <private/qobject_p.h>

#ifndef QT_NO_DBUS

QT_BEGIN_NAMESPACE

/*!

    \class QDBusPendingCall

    \inmodule QtDBus

    \since 4.5

    \brief The QDBusPendingCall class refers to one pending asynchronous call

    A QDBusPendingCall object is a reference to a method call that was

    sent over D-Bus without waiting for a reply. QDBusPendingCall is an

    opaque type, meant to be used as a handle for a pending reply.

    In most programs, the QDBusPendingCall class will not be used

    directly. It can be safely replaced with the template-based

    QDBusPendingReply, in order to access the contents of the reply or

    wait for it to be complete.

    The QDBusPendingCallWatcher class allows one to connect to a signal

    that will indicate when the reply has arrived or if the call has

    timed out. It also provides the

    QDBusPendingCallWatcher::waitForFinished() method which will suspend

    the execution of the program until the reply has arrived.

    \note If you create a copy of a QDBusPendingCall object, all

          information will be shared among the many copies. Therefore,

          QDBusPendingCall is an explicitly-shared object and does not

          provide a method of detaching the copies (since they refer

          to the same pending call)

    \sa QDBusPendingReply, QDBusPendingCallWatcher,

        QDBusAbstractInterface::asyncCall()

*/

/*!

    \class QDBusPendingCallWatcher

    \inmodule QtDBus

    \since 4.5

    \brief The QDBusPendingCallWatcher class provides a convenient way for

    waiting for asynchronous replies

    The QDBusPendingCallWatcher provides the finished() signal that will be

    emitted when a reply arrives.

    It is usually used like the following example:

    \snippet doc/src/snippets/code/src.qdbus.qdbuspendingcall.cpp 0

    Note that it is not necessary to keep the original QDBusPendingCall

    object around since QDBusPendingCallWatcher inherits from that class

    too.

    The slot connected to by the above code could be something similar

    to the following:

    \snippet doc/src/snippets/code/src.qdbus.qdbuspendingcall.cpp 1

    Note the use of QDBusPendingReply to validate the argument types in

    the reply. If the reply did not contain exactly two arguments

    (one string and one QByteArray), QDBusPendingReply::isError() will

    return true.

    \sa QDBusPendingReply, QDBusAbstractInterface::asyncCall()

*/

/*!

    \fn void QDBusPendingCallWatcher::finished(QDBusPendingCallWatcher *self)

    This signal is emitted when the pending call has finished and its

    reply is available. The \a self parameter is a pointer to the

    object itself, passed for convenience so that the slot can access

    the properties and determine the contents of the reply.

*/

void QDBusPendingCallWatcherHelper::add(QDBusPendingCallWatcher *watcher)

{

    connect(this, SIGNAL(finished()), watcher, SLOT(_q_finished()), Qt::QueuedConnection);

}

QDBusPendingCallPrivate::~QDBusPendingCallPrivate()

{

    if (pending) {

        q_dbus_pending_call_cancel(pending);

        q_dbus_pending_call_unref(pending);

    }

    delete watcherHelper;

}

bool QDBusPendingCallPrivate::setReplyCallback(QObject *target, const char *member)

{

    receiver = target;

    metaTypes.clear();

    methodIdx = -1;

    if (!target)

        return true;;           // unsetting

    if (!member || !*member) {

        // would not be able to deliver a reply

        qWarning("QDBusPendingCall::setReplyCallback: error: cannot deliver a reply to %s::%s (%s)",

                 target ? target->metaObject()->className() : "(null)",

                 member ? member + 1 : "(null)",

                 target ? qPrintable(target->objectName()) : "no name");

        return false;

    }

    methodIdx = QDBusConnectionPrivate::findSlot(target, member + 1, metaTypes);

    if (methodIdx == -1) {

        QByteArray normalizedName = QMetaObject::normalizedSignature(member + 1);

        methodIdx = QDBusConnectionPrivate::findSlot(target, normalizedName, metaTypes);

    }

    if (methodIdx == -1) {

        // would not be able to deliver a reply

        qWarning("QDBusPendingCall::setReplyCallback: error: cannot deliver a reply to %s::%s (%s)",

                 target->metaObject()->className(),

                 member + 1, qPrintable(target->objectName()));

        return false;

    }

    // success

    // construct the expected signature

    int count = metaTypes.count() - 1;

    if (count == 1 && metaTypes.at(1) == QDBusMetaTypeId::message) {

        // wildcard slot, can receive anything, so don't set the signature

        return true;

    }

    if (metaTypes.at(count) == QDBusMetaTypeId::message)

        --count;

    // QList<int> is actually a vector

    // kids, don't try this at home

    setMetaTypes(count, count ? &metaTypes.at(1) : 0);

    return true;

}

void QDBusPendingCallPrivate::setMetaTypes(int count, const int *types)

{

    expectedReplyCount = count;

    if (count == 0) {

        expectedReplySignature = QLatin1String(""); // not null

        return;

    }

    QByteArray sig;

    sig.reserve(count + count / 2);

    for (int i = 0; i < count; ++i) {

        const char *typeSig = QDBusMetaType::typeToSignature(types[i]);

        if (!typeSig) {

            qFatal("QDBusPendingReply: type %s is not registered with QtDBus",

                   QMetaType::typeName(types[i]));

        }

        sig += typeSig;

    }

    expectedReplySignature = QString::fromLatin1(sig);

}

void QDBusPendingCallPrivate::checkReceivedSignature()

{

    // MUST BE CALLED WITH A LOCKED MUTEX!

    if (replyMessage.type() == QDBusMessage::InvalidMessage)

        return;                 // not yet finished - no message to

                                // validate against

    if (replyMessage.type() == QDBusMessage::ErrorMessage)

        return;                 // we don't have to check the signature of an error reply

    if (expectedReplySignature.isNull())

        return;                 // no signature to validate against

    // can't use startsWith here because a null string doesn't start or end with an empty string

    if (!replyMessage.signature().indexOf(expectedReplySignature) == 0) {

        QString errorMsg = QLatin1String("Unexpected reply signature: got \"%1\", "

                                         "expected \"%2\"");

        replyMessage = QDBusMessage::createError(

            QDBusError::InvalidSignature,

            errorMsg.arg(replyMessage.signature(), expectedReplySignature));

    }

}

void QDBusPendingCallPrivate::waitForFinished()

{

    QMutexLocker locker(&mutex);

    if (replyMessage.type() != QDBusMessage::InvalidMessage)

        return;                 // already finished

    connection->waitForFinished(this);

}

/*!

    Creates a copy of the \a other pending asynchronous call. Note

    that both objects will refer to the same pending call.

*/

QDBusPendingCall::QDBusPendingCall(const QDBusPendingCall &other)

    : d(other.d)

{

}

/*!

    \internal

*/

QDBusPendingCall::QDBusPendingCall(QDBusPendingCallPrivate *dd)

    : d(dd)

{

}

/*!

    Destroys this copy of the QDBusPendingCall object. If this copy is

    also the last copy of a pending asynchronous call, the call will

    be canceled and no further notifications will be received. There

    will be no way of accessing the reply's contents when it arrives.

*/

QDBusPendingCall::~QDBusPendingCall()

{

    // d deleted by QExplicitlySharedDataPointer

}

/*!

    Creates a copy of the \a other pending asynchronous call and drops

    the reference to the previously-referenced call. Note that both

    objects will refer to the same pending call after this function.

    If this object contained the last reference of a pending

    asynchronous call, the call will be canceled and no further

    notifications will be received. There will be no way of accessing

    the reply's contents when it arrives.

*/

QDBusPendingCall &QDBusPendingCall::operator=(const QDBusPendingCall &other)

{

    d = other.d;

    return *this;

}

/*!

    \fn bool QDBusPendingCallWatcher::isFinished() const

    Returns true if the pending call has finished processing and the

    reply has been received.

    Note that this function only changes state if you call

    waitForFinished() or if an external D-Bus event happens, which in

    general only happens if you return to the event loop execution.

    \sa QDBusPendingReply::isFinished()

*/

/*!

    \fn bool QDBusPendingReply::isFinished() const

    Returns true if the pending call has finished processing and the

    reply has been received. If this function returns true, the

    isError(), error() and reply() methods should return valid

    information.

    Note that this function only changes state if you call

    waitForFinished() or if an external D-Bus event happens, which in

    general only happens if you return to the event loop execution.

    \sa QDBusPendingCallWatcher::isFinished()

*/

bool QDBusPendingCall::isFinished() const

{

    if (!d)

        return true; // considered finished

    QMutexLocker locker(&d->mutex);

    return d->replyMessage.type() != QDBusMessage::InvalidMessage;

}

void QDBusPendingCall::waitForFinished()

{

    if (d) d->waitForFinished();

}

/*!

    \fn bool QDBusPendingReply::isValid() const

    Returns true if the reply contains a normal reply message, false

    if it contains anything else.

    If the pending call has not finished processing, this function

    return false.

*/

bool QDBusPendingCall::isValid() const

{

    if (!d)

        return false;

    QMutexLocker locker(&d->mutex);

    return d->replyMessage.type() == QDBusMessage::ReplyMessage;

}

/*!

    \fn bool QDBusPendingReply::isError() const

    Returns true if the reply contains an error message, false if it

    contains a normal method reply.

    If the pending call has not finished processing, this function

    also returns true.

*/

bool QDBusPendingCall::isError() const

{

    if (!d)

        return true; // considered finished and an error

    QMutexLocker locker(&d->mutex);

    return d->replyMessage.type() == QDBusMessage::ErrorMessage;

}

/*!

    \fn QDBusError QDBusPendingReply::error() const

    Retrieves the error content of the reply message, if it has

    finished processing. If the reply message has not finished

    processing or if it contains a normal reply message (non-error),

    this function returns an invalid QDBusError.

*/

QDBusError QDBusPendingCall::error() const

{

    if (d) {

        QMutexLocker locker(&d->mutex);

        return d->replyMessage;

    }

    // not connected, return an error

    QDBusError err = QDBusError(QDBusError::Disconnected,

                                QLatin1String("Not connected to D-Bus server"));

    return err;

}

/*!

    \fn QDBusMessage QDBusPendingReply::reply() const

    Retrieves the reply message received for the asynchronous call

    that was sent, if it has finished processing. If the pending call

    is not finished, this function returns a QDBusMessage of type

    QDBusMessage::InvalidMessage.

    After it has finished processing, the message type will either be

    an error message or a normal method reply message.

*/

QDBusMessage QDBusPendingCall::reply() const

{

    if (!d)

        return QDBusMessage::createError(error());

    QMutexLocker locker(&d->mutex);

    return d->replyMessage;

}

#if 0

/*!

    Sets the slot \a member in object \a target to be called when the

    reply arrives. The slot's parameter list must match the reply

    message's arguments for it to be called.

    It may, optionally, contain a QDBusMessage final parameter. If it

    is present, the parameter will contain the reply message object.

    The callback will not be called if the reply is an error message.

    This function returns true if it could set the callback, false

    otherwise. It is not a guarantee that the callback will be

    called.

    \warning QDBusPendingCall only supports one callback per pending

             asynchronous call, even if multiple QDBusPendingCall

             objects are referencing the same pending call.

*/

bool QDBusPendingCall::setReplyCallback(QObject *target, const char *member)

{

    if (!d)

        return false;

    return d->setReplyCallback(target, member);

}

#endif

/*!

    \since 4.6

    Creates a QDBusPendingCall object based on the error condition

    \a error. The resulting pending call object will be in the

    "finished" state and QDBusPendingReply::isError() will return true.

    \sa fromCompletedCall()

*/

QDBusPendingCall QDBusPendingCall::fromError(const QDBusError &error)

{

    return fromCompletedCall(QDBusMessage::createError(error));

}

/*!

    \since 4.6

    Creates a QDBusPendingCall object based on the message \a msg.

    The message must be of type QDBusMessage::ErrorMessage or

    QDBusMessage::ReplyMessage (that is, a message that is typical

    of a completed call).

    This function is useful for code that requires simulating a pending

    call, but that has already finished.

    \sa fromError()

*/

QDBusPendingCall QDBusPendingCall::fromCompletedCall(const QDBusMessage &msg)

{

    QDBusPendingCallPrivate *d = 0;

    if (msg.type() == QDBusMessage::ErrorMessage ||

        msg.type() == QDBusMessage::ReplyMessage) {

        d = new QDBusPendingCallPrivate(QDBusMessage(), 0);

        d->replyMessage = msg;

    }

    return QDBusPendingCall(d);

}

class QDBusPendingCallWatcherPrivate: public QObjectPrivate

{

public:

    void _q_finished();

    Q_DECLARE_PUBLIC(QDBusPendingCallWatcher)

};

inline void QDBusPendingCallWatcherPrivate::_q_finished()

{

    Q_Q(QDBusPendingCallWatcher);

    emit q->finished(q);

}

/*!

    Creates a QDBusPendingCallWatcher object to watch for replies on the

    asynchronous pending call \a call and sets this object's parent

    to \a parent.

*/

QDBusPendingCallWatcher::QDBusPendingCallWatcher(const QDBusPendingCall &call, QObject *parent)

    : QObject(*new QDBusPendingCallWatcherPrivate, parent), QDBusPendingCall(call)

{

    if (d) {                    // QDBusPendingCall::d

        QMutexLocker locker(&d->mutex);

        if (!d->watcherHelper) {

            d->watcherHelper = new QDBusPendingCallWatcherHelper;

            if (d->replyMessage.type() != QDBusMessage::InvalidMessage) {

                // cause a signal emission anyways

                QMetaObject::invokeMethod(d->watcherHelper, "finished", Qt::QueuedConnection);

            }

        }

        d->watcherHelper->add(this);

    }

}

/*!

    Destroys this object. If this QDBusPendingCallWatcher object was the

    last reference to the unfinished pending call, the call will be

    canceled.

*/

QDBusPendingCallWatcher::~QDBusPendingCallWatcher()

{

}

/*!

    \fn void QDBusPendingCallWatcher::waitForFinished()

    Suspends the execution of the calling thread until the reply is

    received and processed. After this function returns, isFinished()

    should return true, indicating the reply's contents are ready to

    be processed.

    \sa QDBusPendingReply::waitForFinished()

*/

void QDBusPendingCallWatcher::waitForFinished()