/** ===========================================================
 * @file
 *
 * This file is a part of digiKam project
 * <a href="http://www.digikam.org">http://www.digikam.org</a>
 *
 * @date   2009-12-01
 * @brief  Widget for displaying HTML in the backends
 *
 * @author Copyright (C) 2009-2011 by Michael G. Hansen
 *         <a href="mailto:mike at mghansen dot de">mike at mghansen dot de</a>
 * @author Copyright (C) 2010-2015 by Gilles Caulier
 *         <a href="mailto:caulier dot gilles at gmail dot com">caulier dot gilles at gmail dot com</a>
 * @author Copyright (C) 2015      by Mohamed Anwer
 *         <a href="mailto:mohammed.ahmed.anwer@gmail.com">mohammed dot ahmed dot anwer at gmail dot com</a>
 *
 * 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, 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.
 *
 * ============================================================ */

#include "htmlwidget.h"

// Qt includes

#include <QTimer>
#include <QResizeEvent>
#include <QWebView>
#include <QWebFrame>

// Local includes

#include "geoiface_common.h"
#include "geoiface_types.h"
#include "digikam_debug.h"

namespace GeoIface
{

class HTMLWidget::Private
{
public:

    Private()
      : parent(0),
        isReady(false),
        selectionStatus(false),
        firstSelectionPoint(),
        intermediateSelectionPoint(),
        firstSelectionScreenPoint(),
        intermediateSelectionScreenPoint()
    {
    }

    QWidget*       parent;
    bool           isReady;

    bool           selectionStatus;
    GeoCoordinates firstSelectionPoint;
    GeoCoordinates intermediateSelectionPoint;
    QPoint         firstSelectionScreenPoint;
    QPoint         intermediateSelectionScreenPoint;
};

HTMLWidget::HTMLWidget(QWidget* const parent)
    : QWebView(parent),
      d(new Private()),
      s(0)
{
    d->parent = parent;
    setAcceptDrops(false);
    setFocusPolicy(Qt::WheelFocus);
    setRenderHint(QPainter::TextAntialiasing);
    page()->setLinkDelegationPolicy(QWebPage::DelegateAllLinks);

    d->parent->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);

    connect(this, SIGNAL(loadProgress(int)),
            this, SLOT(progress(int)));

    connect(this, SIGNAL(loadFinished(bool)),
            this, SLOT(slotHTMLCompleted(bool)));

    connect(this, SIGNAL(statusBarMessage(QString)),
            this, SLOT(slotScanForJSMessages(QString)));

    if (d->parent)
    {
        d->parent->installEventFilter(this);
    }
}

HTMLWidget::~HTMLWidget()
{
    delete d;
}

void HTMLWidget::progress(int progress)
{
    qCDebug(DIGIKAM_GEOIFACE_LOG) << "Maps Loading Progress: " << progress << "%";
}

void HTMLWidget::slotHTMLCompleted(bool ok)
{
    qCDebug(DIGIKAM_GEOIFACE_LOG) << "Map Loading Completed: " << ok;
    d->isReady = ok;

    emit(signalJavaScriptReady());
}

void HTMLWidget::mousePressEvent(QMouseEvent* e)
{
    slotScanForJSMessages(QString::fromLatin1("(event)"));
    QWebView::mousePressEvent(e);
}

void HTMLWidget::mouseReleaseEvent(QMouseEvent* e)
{
    if (s->currentMouseMode == MouseModeRegionSelection)
    {
        if (!d->firstSelectionPoint.hasCoordinates())
        {
            runScript2Coordinates(QString::fromLatin1("kgeomapPixelToLatLng(%1, %2);")
                                  .arg(e->x())
                                  .arg(e->y()),
                                  &d->firstSelectionPoint);

            d->firstSelectionScreenPoint = QPoint(e->x(), e->y());
        }
        else
        {
            runScript2Coordinates(QString::fromLatin1("kgeomapPixelToLatLng(%1, %2);")
                                  .arg(e->x())
                                  .arg(e->y()),
                                  &d->intermediateSelectionPoint);

            d->intermediateSelectionScreenPoint = QPoint(e->x(), e->y());

            qreal lonWest, latNorth, lonEast, latSouth;

            if (d->firstSelectionScreenPoint.x() < d->intermediateSelectionScreenPoint.x())
            {
                lonWest  = d->firstSelectionPoint.lon();
                lonEast  = d->intermediateSelectionPoint.lon();
            }
            else
            {
                lonEast  = d->firstSelectionPoint.lon();
                lonWest  = d->intermediateSelectionPoint.lon();
            }

            if (d->firstSelectionScreenPoint.y() < d->intermediateSelectionScreenPoint.y())
            {
                latNorth = d->firstSelectionPoint.lat();
                latSouth = d->intermediateSelectionPoint.lat();
            }
            else
            {
                latNorth = d->intermediateSelectionPoint.lat();
                latSouth = d->firstSelectionPoint.lat();
            }

            runScript(QLatin1String("kgeomapRemoveTemporarySelectionRectangle();"));
            runScript(QString::fromLatin1("kgeomapSetSelectionRectangle(%1, %2, %3, %4);")
                     .arg(lonWest)
                     .arg(latNorth)
                     .arg(lonEast)
                     .arg(latSouth));

            const GeoCoordinates::Pair selectionCoordinates(
                    GeoCoordinates(latNorth, lonWest),
                    GeoCoordinates(latSouth, lonEast)
                );

            d->firstSelectionPoint.clear();
            d->intermediateSelectionPoint.clear();

            emit(selectionHasBeenMade(selectionCoordinates));
        }
    }

    slotScanForJSMessages(QString::fromLatin1("(event)"));
    QWebView::mouseReleaseEvent(e);
}

void HTMLWidget::mouseMoveEvent(QMouseEvent *e)
{
    if (s->currentMouseMode == MouseModeRegionSelection &&
        d->firstSelectionPoint.hasCoordinates())
    {
        runScript2Coordinates(QString::fromLatin1("kgeomapPixelToLatLng(%1, %2);")
                              .arg(e->x())
                              .arg(e->y()),
                              &d->intermediateSelectionPoint);

        d->intermediateSelectionScreenPoint = QPoint(e->x(), e->y());

        qCDebug(DIGIKAM_GEOIFACE_LOG) << d->firstSelectionScreenPoint << QLatin1String(" ") << d->intermediateSelectionScreenPoint;

        qreal lonWest, latNorth, lonEast, latSouth;

        if (d->firstSelectionScreenPoint.x() < d->intermediateSelectionScreenPoint.x())
        {
            lonWest  = d->firstSelectionPoint.lon();
            lonEast  = d->intermediateSelectionPoint.lon();
        }
        else
        {
            lonEast  = d->firstSelectionPoint.lon();
            lonWest  = d->intermediateSelectionPoint.lon();
        }

        if (d->firstSelectionScreenPoint.y() < d->intermediateSelectionScreenPoint.y())
        {
            latNorth = d->firstSelectionPoint.lat();
            latSouth = d->intermediateSelectionPoint.lat();
        }
        else
        {
            latNorth = d->intermediateSelectionPoint.lat();
            latSouth = d->firstSelectionPoint.lat();
        }

        runScript(QString::fromLatin1("kgeomapSetTemporarySelectionRectangle(%1, %2, %3, %4);")
                  .arg(lonWest)
                  .arg(latNorth)
                  .arg(lonEast)
                  .arg(latSouth));
    }

    QWebView::mouseMoveEvent(e);
}

void HTMLWidget::slotScanForJSMessages(const QString& message)
{
    if (message != QLatin1String("(event)"))
        return;

//    qCDebug(DIGIKAM_GEOIFACE_LOG) << message;

    const QString eventBufferString = runScript(QLatin1String("kgeomapReadEventStrings();")).toString();

    if (eventBufferString.isEmpty())
        return;

    const QStringList events = eventBufferString.split(QLatin1Char('|'));

    emit(signalHTMLEvents(events));
}

/**
 * @brief Wrapper around executeScript to catch more errors
 */
QVariant HTMLWidget::runScript(const QString& scriptCode)
{
    GEOIFACE_ASSERT(d->isReady);

    if (!d->isReady)
        return QVariant();

//     qCDebug(DIGIKAM_GEOIFACE_LOG) << scriptCode;
    return page()->mainFrame()->evaluateJavaScript(scriptCode);
}

/**
 * @brief Execute a script which returns coordinates and parse these
 */
bool HTMLWidget::runScript2Coordinates(const QString& scriptCode, GeoCoordinates* const coordinates)
{
    const QVariant scriptResult = runScript(scriptCode);

    return GeoIfaceHelperParseLatLonString(scriptResult.toString(), coordinates);
}

bool HTMLWidget::eventFilter(QObject* object, QEvent* event)
{
    if (d->parent && object == d->parent)
    {

        if (event->type() == QEvent::Resize)
        {
            QResizeEvent* const resizeEvent = dynamic_cast<QResizeEvent*>(event);

            if (resizeEvent)
            {
                resize(resizeEvent->size());
            }
        }
    }

    return false;
}

void HTMLWidget::setSelectionRectangle(const GeoCoordinates::Pair& searchCoordinates)
{
    if (!searchCoordinates.first.hasCoordinates())
    {
        runScript(QString::fromLatin1("kgeomapRemoveSelectionRectangle();"));
        return;
    }

    qreal West  = searchCoordinates.first.lon();
    qreal North = searchCoordinates.first.lat();
    qreal East  = searchCoordinates.second.lon();
    qreal South = searchCoordinates.second.lat();

    runScript(QString::fromLatin1("kgeomapSetSelectionRectangle(%1, %2, %3, %4);").arg(West).arg(North).arg(East).arg(South));
}

void HTMLWidget::removeSelectionRectangle()
{
    runScript(QLatin1String("kgeomapRemoveSelectionRectangle();"));
}

void HTMLWidget::mouseModeChanged(const MouseModes mouseMode)
{
    const bool inSelectionMode = (mouseMode == MouseModeRegionSelection);

    if (inSelectionMode)
    {
        d->firstSelectionPoint.clear();
        d->intermediateSelectionPoint.clear();
        runScript(QString::fromLatin1("kgeomapSelectionModeStatus(%1);").arg(inSelectionMode));
    }
    else
    {
        runScript(QString::fromLatin1("kgeomapSelectionModeStatus(%1);").arg(inSelectionMode));
    }
}

void HTMLWidget::centerOn(const qreal west, const qreal north, const qreal east, const qreal south, const bool useSaneZoomLevel)
{
//    qCDebug(DIGIKAM_GEOIFACE_LOG) << "West:" << west << " North:" << north << " East:" << east << " South:" << south;
    runScript(QString::fromLatin1("kgeomapSetMapBoundaries(%1, %2, %3, %4, %5);")
              .arg(west)
              .arg(north)
              .arg(east)
              .arg(south)
              .arg(useSaneZoomLevel ? 1 : 0));
}

void HTMLWidget::setSharedGeoIfaceObject(GeoIfaceSharedData* const sharedData)
{
    s = sharedData;
}

} /* namespace GeoIface */
