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****************************************************************************/
#include "mapsphere_p.h"

#include "tilecache.h"
#include "tilespec.h"
#include "tile.h"
#include "map.h"
#include "map_p.h"

#include <Qt3D/qglscenenode.h>

#include <QVector>

MapSphere::MapSphere(Map* map, MapPrivate *mapPrivate, TileCache *tileCache)
    : QObject(0),
      tileCache_(tileCache),
      mapPrivate_(mapPrivate)
{

    sphereNode_ = new QGLSceneNode(this);

    connect(tileCache_,
            SIGNAL(prefetchingFinished()),
            this,
            SLOT(prefetchingFinished()));
    connect(tileCache_,
            SIGNAL(tileFetched(TileSpec)),
            this,
            SLOT(tileFetched(TileSpec)));

    connect(this,
            SIGNAL(tileUpdated()),
            map,
            SIGNAL(updateRequired()));

    connect(this,
            SIGNAL(sphereUpdated()),
            map,
            SIGNAL(updatesFinished()));
}

MapSphere::~MapSphere()
{
    QList<QGLSceneNode*> nodes = built_.values();
    for (int i = 0; i < nodes.size(); ++i) {
        QGLSceneNode *node = nodes.at(i);
        //node->material()->texture()->release();
        node->geometry().clear();
        sphereNode_->removeNode(node);
        delete node;
    }
}

void MapSphere::setMappingManager(QGeoMappingManager *manager)
{
    tileCache_->setMappingManager(manager);
}

QGLSceneNode* MapSphere::sphereSceneNode() const
{
    return sphereNode_;
}

void MapSphere::clearCache()
{
    // clear cache
}

// Function to perform housekeeping that require access to GL context
// (access to GL context varies depending on if we are running as
// c++ app or QML app).
void MapSphere::GLContextAvailable()
{
    // need something like this in the cache for
    // releasing textures and freeing nodes that
    // have been evicted from the GPU
    tileCache_->GLContextAvailable(sphereNode_);
//    qDeleteAll(obsoleteNodes_);
//    obsoleteNodes_.clear();
}

void MapSphere::update(const QList<TileSpec> &tiles)
{
    QHash<TileSpec, QGLSceneNode*> stillBuilt;

    QVector<TileSpec> req(tiles.size());
    QVector<TileSpec> draw(tiles.size());

    int reqSize = 0;
    int drawSize = 0;
    QList<TileSpec>::const_iterator i = tiles.constBegin();
    QList<TileSpec>::const_iterator tilesEnd = tiles.constEnd();
    while (i != tilesEnd) {
        bool use = true;

        /*
          If the tile is already built or has been requested then we
          shouldn't use it (where "use" means drawing a cached tile or
          requested an uncached tile).
        */

        if (built_.contains(*i)) {
            stillBuilt.insert(*i, built_.value(*i));
            use = false;
        } else if (requested_.contains(*i)){
            use = false;
        }

        /*
          Otherwise we add it to the correct list
        */

        if (use) {
            if (tileCache_->contains(*i)) {
                draw[drawSize] = *i;
                ++drawSize;
            } else {
                req[reqSize] = *i;
                ++reqSize;
                requested_.insert(*i);
            }
        }

        ++i;
    }

    req.resize(reqSize);
//    draw.resize(drawSize);

    updateMutex.lock();

    QHash<TileSpec, QGLSceneNode*>::const_iterator j = built_.constBegin();
    QHash<TileSpec, QGLSceneNode*>::const_iterator end = built_.constEnd();
    while (j != end) {
        TileSpec spec = j.key();
        if (!stillBuilt.contains(spec)) {
            sphereNode_->removeNode(j.value());
        }
        ++j;
    }
    built_.swap(stillBuilt);

    updateMutex.unlock();

    for (int i = 0; i < drawSize; ++i)
            displayTile(draw.at(i));

    if (req.isEmpty()) {
        emit sphereUpdated();
    } else {
        tileCache_->prefetch(req.toList());
    }
}

void MapSphere::prefetchingFinished()
{
    emit sphereUpdated();
}

void MapSphere::tileFetched(const TileSpec &spec)
{
    if (!requested_.contains(spec))
        return;

    displayTile(spec);

    requested_.remove(spec);

    emit tileUpdated();
}

void MapSphere::displayTile(const TileSpec &spec)
{
    if (built_.contains(spec))
        return;

    updateMutex.lock();
    Tile tile = tileCache_->get(spec);
    QGLSceneNode *node = tile.sceneNode();
    if (!node) {
        node = mapPrivate_->createTileNode(tile);
        tile.setSceneNode(node);
        tile.bind();
        tileCache_->update(spec, tile);
    }
    if (node) {
        sphereNode_->addNode(node);
        built_.insert(spec, node);
    }
    updateMutex.unlock();

//    qWarning() << tileCache_->diskUsage() << tileCache_->maxDiskUsage()
//               << tileCache_->memoryUsage() << tileCache_->maxMemoryUsage()
//               << tileCache_->textureUsage() << tileCache_->maxTextureUsage();
}