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

#include "thumbnailnode.h"
#include "qglpainter.h"
#include "thumbnaileffect.h"
#include "imagemanager.h"
#include "qatlas.h"
#include "qglrendersequencer.h"
#include "qglpicknode.h"
#include "qlogicalvertex.h"

#include <QMatrix4x4>
#include <QTimer>

ThumbnailNode::ThumbnailNode(QObject *parent)
    : QGLSceneNode(parent)
    , m_thresholdSquared(20.0f * 20.0f)
    , m_defaultMaterial(-1)
    , m_loading(false)
    , m_full(0)
    , m_manager(0)
    , m_lastDistance(ThumbnailNode::Unknown)
{
    setPalette(new QGLMaterialCollection(this));
}

ThumbnailNode::~ThumbnailNode()
{
    delete m_full;
}

void ThumbnailNode::setUrl(const QUrl &url)
{
    m_url = url;
    m_image = ThumbnailableImage();
    m_image.setUrl(m_url);
    QGL::IndexArray inxs = geometry().indices();
    m_image.setIndices(inxs.mid(start(), count()));
}

void ThumbnailNode::setupLoading()
{
    if (!m_loading && !m_url.isEmpty() && m_image.data().isNull())
    {
        m_loading = true;
#ifdef QT_NO_THREADED_FILE_LOAD
        ThumbnailableImage image;
        image.setUrl(m_url);
        QImage im(m_url.toLocalFile());
        if (im.isNull())
            qDebug() << "ThumbnailNode::setupLoading: could not load image:"
                     << m_url.toLocalFile();
        if (im.size().width() > 1024 || im.size().height() > 768)
            im = im.scaled(QSize(1024, 768), Qt::KeepAspectRatio,
                           Qt::SmoothTransformation);
        image.setData(im);
        setImage(image);
#else
        if (m_manager)
            // reconnect the signal we disconnnected in setImage() below
            connect(m_manager, SIGNAL(imageReady(ThumbnailableImage)),
                    this, SLOT(setImage(ThumbnailableImage)));
        emit imageRequired(m_image);
        setMaterialIndex(m_defaultMaterial);
#endif
    }
}

void ThumbnailNode::createFullNode()
{
    m_full = new QGLSceneNode;
    m_full->setPosition(position());
    m_full->setGeometry(geometry());
    m_full->setStart(start());
    m_full->setCount(count());
    m_full->setPalette(palette());
    m_full->setMaterialIndex(m_defaultMaterial);
}

void ThumbnailNode::destroyFullNode()
{
    if (!m_full)
        return;
    QGLMaterial *mat = m_full->material();
    if (m_full->materialIndex() != m_defaultMaterial)
        m_full->palette()->removeMaterial(mat);
    delete m_full;
    m_full = 0;
}

void ThumbnailNode::loadFullImage()
{
    if (!m_full)
        createFullNode();
    Q_CHECK_PTR(m_full);
    // if we have a valid image, and the full node still has the
    // default material, switch to a new material which displays
    // the full size image
    if (!m_image.data().isNull() &&
            m_full->materialIndex() == m_defaultMaterial)
    {
        QGLMaterial *mat = new QGLMaterial;
        QGLTexture2D *tex = new QGLTexture2D;
        tex->setImage(m_image.data());
        mat->setTexture(tex);
        mat->setObjectName(m_image.url().path());
        int ix = palette()->addMaterial(mat);
        m_full->setMaterialIndex(ix);
        mat->setParent(m_full);
    }
}

void ThumbnailNode::drawGeometry(QGLPainter *painter)
{
    QGLSceneNode::drawGeometry(painter);
}

void ThumbnailNode::draw(QGLPainter *painter)
{
    QGLSceneNode *p = qobject_cast<QGLSceneNode*>(parent());
    Q_ASSERT_X(p && p->userEffect() && (!hasEffect()),
               "ThumbnailNode::draw", "Should only inherit parents ThumbnailEffect");

    ThumbnailEffect *effect = static_cast<ThumbnailEffect*>(p->userEffect());
    Q_ASSERT_X(effect && effect->name() == QLatin1String("ThumbnailEffect"),
               "ThumbnailNode::draw", "Can only be drawn with custom ThumbnailEffect");

    if (m_defaultMaterial == -1)
        m_defaultMaterial = materialIndex();

    QMatrix4x4 m = painter->modelViewMatrix().top();
    QVector3D pos = m.map(position());
    qreal magSquared = pos.lengthSquared();

    Distance distance = Unknown;

    if (magSquared > (4.0f * m_thresholdSquared))
        distance = VeryFar;
    else if (magSquared > (2.0f * m_thresholdSquared))
        distance = Far;
    else if (magSquared > m_thresholdSquared)
        distance = Middle;
    else
        distance = Near;

    if (true) // distance != m_lastDistance)
    {
        m_lastDistance = distance;
        m_image.setThumbnailed(m_lastDistance > Near);
        switch (distance)
        {
        case Unknown:
        case Near:
            setupLoading();
            loadFullImage();
            break;
        case Middle:
            setupLoading();
            loadFullImage();
            break;
        case Far:
            setupLoading();
            break;
        case VeryFar:
            destroyFullNode();
            break;
        }
    }

    effect->setThumbnail(m_image.isThumbnailed());
    if (m_image.isThumbnailed() || !m_full)
    {
        QGLSceneNode::draw(painter);
    }
    else
    {
        if (m_image.data().isNull())
            m_full->setMaterialIndex(m_defaultMaterial);
        if (pickNode() && painter->isPicking())
            painter->setObjectPickId(pickNode()->id());
        m_full->draw(painter);
    }

}

void ThumbnailNode::setImage(const ThumbnailableImage &image)
{
    Q_ASSERT(QThread::currentThread() == thread());
    Q_ASSERT(!image.isNull());

    // the manager will be (potentially) loading a number of images, but
    // we only want our one, so just check this is our order
    if (m_url != image.url())
        return;

    // ok we got the right one, stop listening to the manager
    if (sender())
    {
        m_manager = sender();
        m_manager->disconnect(this, SLOT(setImage(ThumbnailableImage)));
    }

    // ok maybe we got what we asked for but in the meantime we decided
    // we did not want it anymore
    if (!m_loading)
        return;

    // the indices we are about to set will index this thumbnail image
    // into the image that its atlas is based on via the texture coords
    // that the atlas is using - those texture coords must be in the
    // same geometry that this node is referencing, so that they will
    // arrive at the vertex shader at the same time - ie they are all
    // matched in the data arrays in the geometry object
    //Q_ASSERT(QAtlas::instance()->geometry() == geometry());

    m_image = image;
    Q_ASSERT(!m_image.data().isNull());

    // configure the placeholder for the actual image size
    // this makes a photo of 1024 x 768 display on approx 3.0 x 2.8 pane
    // add salt to taste
    //QSizeF f = QSizeF(m_image.data().size()) / 600.0f;
    QSizeF f = QSizeF(m_image.data().size());
    f.scale(1.6, 1.2, Qt::KeepAspectRatio);
    QVector3D a(-f.width(), -f.height(), 0.0f);
    QVector3D b(f.width(), -f.height(), 0.0f);
    QVector3D c(f.width(), f.height(), 0.0f);
    QVector3D d(-f.width(), f.height(), 0.0f);
    int k = start();
    Q_ASSERT(count() == 6);
    QGeometryData g = geometry();
    QGL::IndexArray inxs = g.indices();
    g.vertex(inxs.at(k)) = a;
    g.vertex(inxs.at(k+1)) = b;
    g.vertex(inxs.at(k+2)) = c;
    g.vertex(inxs.at(k+5)) = d;

    setMaterialIndex(-1);
    m_loading = false;

    emit nodeChanged();
}