/*
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "UBThumbnailAdaptor.h"

#include <QtCore>

#include "frameworks/UBFileSystemUtils.h"

#include "core/UBPersistenceManager.h"
#include "core/UBApplication.h"
#include "core/UBSettings.h"


#include "gui/UBDockTeacherGuideWidget.h"
#include "gui/UBTeacherGuideWidget.h"

#include "board/UBBoardController.h"
#include "board/UBBoardPaletteManager.h"

#include "document/UBDocumentProxy.h"

#include "domain/UBGraphicsScene.h"

#include "UBSvgSubsetAdaptor.h"

#include "core/memcheck.h"

void UBThumbnailAdaptor::generateMissingThumbnails(UBDocumentProxy* proxy)
{
    int existingPageCount = proxy->pageCount();

    for (int iPageNo = 0; iPageNo < existingPageCount; ++iPageNo)
    {
        QString thumbFileName = proxy->persistencePath() + UBFileSystemUtils::digitFileFormat("/page%1.thumbnail.jpg", iPageNo);

        QFile thumbFile(thumbFileName);

        if (!thumbFile.exists())
        {
            bool displayMessage = (existingPageCount > 5);

            int thumbCount = 0;

            UBGraphicsScene* scene = UBSvgSubsetAdaptor::loadScene(proxy, iPageNo);

            if (scene)
            {
                thumbCount++;

                if (displayMessage && thumbCount == 1)
                    UBApplication::showMessage(tr("Generating preview thumbnails ..."));

                persistScene(proxy, scene, iPageNo);
            }

            if (displayMessage && thumbCount > 0)
                UBApplication::showMessage(tr("%1 thumbnails generated ...").arg(thumbCount));

        }
    }
}

const QPixmap* UBThumbnailAdaptor::get(UBDocumentProxy* proxy, int pageIndex)
{
    QString fileName = proxy->persistencePath() + UBFileSystemUtils::digitFileFormat("/page%1.thumbnail.jpg", pageIndex);

    QFile file(fileName);
    if (!file.exists())
    {
        generateMissingThumbnails(proxy);
    }

    QPixmap* pix = new QPixmap();
    if (file.exists())
    {
        //Warning. Works only with modified Qt
#ifdef Q_WS_X11
        pix->load(fileName, 0, Qt::AutoColor);
#else
        pix->load(fileName, 0, Qt::AutoColor, false);
#endif
    }
    return pix;
}

void UBThumbnailAdaptor::updateDocumentToHandleZeroPage(UBDocumentProxy* proxy)
{
    if(UBSettings::settings()->teacherGuidePageZeroActivated->get().toBool()){
    	QString fileName = proxy->persistencePath() + UBFileSystemUtils::digitFileFormat("/page%1.svg", 0);
    	QFile file(fileName);
    	if(!file.exists()){
    		UBPersistenceManager::persistenceManager()->persistDocumentScene(proxy,new UBGraphicsScene(proxy),0);
    	}
    }
}

void UBThumbnailAdaptor::load(UBDocumentProxy* proxy, QList<const QPixmap*>& list)
{
    updateDocumentToHandleZeroPage(proxy);
	generateMissingThumbnails(proxy);

    foreach(const QPixmap* pm, list)
        delete pm;
    list.clear();
    for(int i=0; i<proxy->pageCount(); i++)
        list.append(get(proxy, i));
}

void UBThumbnailAdaptor::persistScene(UBDocumentProxy* proxy, UBGraphicsScene* pScene, int pageIndex, bool overrideModified)
{
    QString fileName = proxy->persistencePath() + UBFileSystemUtils::digitFileFormat("/page%1.thumbnail.jpg", pageIndex);

    QFile thumbFile(fileName);

    if (pScene->isModified() || overrideModified || !thumbFile.exists() || UBApplication::boardController->paletteManager()->teacherGuideDockWidget()->teacherGuideWidget()->isModified())
    {
        qreal nominalWidth = pScene->nominalSize().width();
        qreal nominalHeight = pScene->nominalSize().height();
        qreal ratio = nominalWidth / nominalHeight;
        QRectF sceneRect = pScene->normalizedSceneRect(ratio);

        qreal width = UBSettings::maxThumbnailWidth;
        qreal height = width / ratio;

        QImage thumb(width, height, QImage::Format_ARGB32);

        QRectF imageRect(0, 0, width, height);

        QPainter painter(&thumb);
        painter.setRenderHint(QPainter::Antialiasing, true);
        painter.setRenderHint(QPainter::SmoothPixmapTransform, true);

        if (pScene->isDarkBackground())
        {
            painter.fillRect(imageRect, Qt::black);
        }
        else
        {
            painter.fillRect(imageRect, Qt::white);
        }

        pScene->setRenderingContext(UBGraphicsScene::NonScreen);
        pScene->setRenderingQuality(UBItem::RenderingQualityHigh);

        pScene->render(&painter, imageRect, sceneRect, Qt::KeepAspectRatio);

        if(UBApplication::boardController->paletteManager()->teacherGuideDockWidget()->teacherGuideWidget()->isModified()){
            QPixmap toque(":images/toque.svg");
            painter.setOpacity(0.6);
            painter.drawPixmap(QPoint(width - toque.width(),0),toque);
        }

        pScene->setRenderingContext(UBGraphicsScene::Screen);
        pScene->setRenderingQuality(UBItem::RenderingQualityNormal);

        thumb.scaled(width, height, Qt::KeepAspectRatio, Qt::SmoothTransformation).save(fileName, "JPG");
    }
}


QUrl UBThumbnailAdaptor::thumbnailUrl(UBDocumentProxy* proxy, int pageIndex)
{
    QString fileName = proxy->persistencePath() + UBFileSystemUtils::digitFileFormat("/page%1.thumbnail.jpg", pageIndex);

    return QUrl::fromLocalFile(fileName);
}