/*  This file is part of the KDE project.

Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

This library is free software: you can redistribute it and/or modify

it under the terms of the GNU Lesser General Public License as published by

the Free Software Foundation, either version 2.1 or 3 of the License.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License

along with this library.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "mediaobject.h"

#include "mmf_medianode.h"

QT_BEGIN_NAMESPACE

using namespace Phonon;

using namespace Phonon::MMF;

/*! \class MMF::MediaNode

  \internal

*/

MMF::MediaNode::MediaNode(QObject *parent)

    :   QObject(parent)

    ,   m_mediaObject(qobject_cast<MediaObject *>(this))

    ,   m_input(0)

{

}

MMF::MediaNode::~MediaNode()

{

    // Phonon framework ensures nodes are disconnected before being destroyed.

    Q_ASSERT_X(!m_mediaObject, Q_FUNC_INFO,

        "Media node not disconnected before destruction");

}

bool MMF::MediaNode::connectOutput(MediaNode *output)

{

    Q_ASSERT_X(output, Q_FUNC_INFO, "Null output pointer");

    bool connected = false;

    // Check that this connection will not result in a graph which

    // containing more than one MediaObject

    const bool mediaObjectMisMatch =

            m_mediaObject

        &&  output->m_mediaObject

        &&  m_mediaObject != output->m_mediaObject;

    const bool canConnect =

            !output->isMediaObject()

        &&  !output->m_input

        &&  !m_outputs.contains(output);

    if (canConnect && !mediaObjectMisMatch) {

        output->m_input = this;

        m_outputs += output;

        updateMediaObject();

        connected = true;

    }

    return connected;

}

bool MMF::MediaNode::disconnectOutput(MediaNode *output)

{

    Q_ASSERT_X(output, Q_FUNC_INFO, "Null output pointer");

    bool disconnected = false;

    if (m_outputs.contains(output) && this == output->m_input) {

        output->m_input = 0;

        const bool removed = m_outputs.removeOne(output);

        Q_ASSERT_X(removed, Q_FUNC_INFO, "Output removal failed");

        Q_ASSERT_X(!m_outputs.contains(output), Q_FUNC_INFO,

            "Output list contains duplicate entries");

        // Perform traversal across each of the two graphs separately

        updateMediaObject();

        output->updateMediaObject();

        disconnected = true;

    }

    return disconnected;

}

bool MMF::MediaNode::isMediaObject() const

{

    return (qobject_cast<const MediaObject *>(this) != 0);

}

void MMF::MediaNode::updateMediaObject()

{

    QList<MediaNode *> nodes;

    MediaObject *mediaObject = 0;

    // Traverse the graph, collecting a list of nodes, and locating

    // the MediaObject node, if present

    visit(nodes, mediaObject);

    MediaNode *node = 0;

    foreach(node, nodes)

        node->setMediaObject(mediaObject);

}

void MMF::MediaNode::setMediaObject(MediaObject *mediaObject)

{

    if(!isMediaObject() && m_mediaObject != mediaObject) {

        if (!mediaObject)

            disconnectMediaObject(m_mediaObject);

        else {

            Q_ASSERT_X(!m_mediaObject, Q_FUNC_INFO, "MediaObject already set");

            connectMediaObject(mediaObject);

        }

        m_mediaObject = mediaObject;

    }

}

void MMF::MediaNode::visit(QList<MediaNode *>& visited, MediaObject*& mediaObject)

{

    if (isMediaObject()) {

        // There can never be more than one MediaObject per graph, due to the

        // mediaObjectMisMatch test in connectOutput().

        Q_ASSERT_X(!mediaObject, Q_FUNC_INFO, "MediaObject already found");

        mediaObject = static_cast<MediaObject *>(this);

    }

    visited += this;

    if (m_input && !visited.contains(m_input))

        m_input->visit(visited, mediaObject);

    MediaNode *output = 0;

    foreach (output, m_outputs)

        if (!visited.contains(output))

            output->visit(visited, mediaObject);

}

QT_END_NAMESPACE