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#include <QtCore>

#include <QtGui>

#include <QtNetwork>

#if defined (Q_OS_SYMBIAN)

#include "sym_iap_util.h"

#endif

#include <math.h>

#ifndef M_PI

#define M_PI 3.14159265358979323846

#endif

// how long (milliseconds) the user need to hold (after a tap on the screen)

// before triggering the magnifying glass feature

// 701, a prime number, is the sum of 229, 233, 239

// (all three are also prime numbers, consecutive!)

#define HOLD_TIME 701

// maximum size of the magnifier

// Hint: see above to find why I picked this one :)

#define MAX_MAGNIFIER 229

uint qHash(const QPoint& p)

{

    return p.x() * 17 ^ p.y();

}

// tile size in pixels

const int tdim = 256;

QPointF tileForCoordinate(qreal lat, qreal lng, int zoom)

{

    qreal zn = static_cast<qreal>(1 << zoom);

    qreal tx = (lng + 180.0) / 360.0;

    qreal ty = (1.0 - log(tan(lat * M_PI / 180.0) +

                          1.0 / cos(lat * M_PI / 180.0)) / M_PI) / 2.0;

    return QPointF(tx * zn, ty * zn);

}

qreal longitudeFromTile(qreal tx, int zoom)

{

    qreal zn = static_cast<qreal>(1 << zoom);

    qreal lat = tx / zn * 360.0 - 180.0;

    return lat;

}

qreal latitudeFromTile(qreal ty, int zoom)

{

    qreal zn = static_cast<qreal>(1 << zoom);

    qreal n = M_PI - 2 * M_PI * ty / zn;

    qreal lng = 180.0 / M_PI * atan(0.5 * (exp(n) - exp(-n)));

    return lng;

}

class SlippyMap: public QObject

{

    Q_OBJECT

public:

    int width;

    int height;

    int zoom;

    qreal latitude;

    qreal longitude;

    SlippyMap(QObject *parent = 0)

            : QObject(parent)

            , width(400)

            , height(300)

            , zoom(15)

            , latitude(59.9138204)

            , longitude(10.7387413) {

        m_emptyTile = QPixmap(tdim, tdim);

        m_emptyTile.fill(Qt::lightGray);

        QNetworkDiskCache *cache = new QNetworkDiskCache;

        cache->setCacheDirectory(QDesktopServices::storageLocation

                                 (QDesktopServices::CacheLocation));

        m_manager.setCache(cache);

        connect(&m_manager, SIGNAL(finished(QNetworkReply*)),

                this, SLOT(handleNetworkData(QNetworkReply*)));

    }

    void invalidate() {

        if (width <= 0 || height <= 0)

            return;

        QPointF ct = tileForCoordinate(latitude, longitude, zoom);

        qreal tx = ct.x();

        qreal ty = ct.y();

        // top-left corner of the center tile

        int xp = width / 2 - (tx - floor(tx)) * tdim;

        int yp = height / 2 - (ty - floor(ty)) * tdim;

        // first tile vertical and horizontal

        int xa = (xp + tdim - 1) / tdim;

        int ya = (yp + tdim - 1) / tdim;

        int xs = static_cast<int>(tx) - xa;

        int ys = static_cast<int>(ty) - ya;

        // offset for top-left tile

        m_offset = QPoint(xp - xa * tdim, yp - ya * tdim);

        // last tile vertical and horizontal

        int xe = static_cast<int>(tx) + (width - xp - 1) / tdim;

        int ye = static_cast<int>(ty) + (height - yp - 1) / tdim;

        // build a rect

        m_tilesRect = QRect(xs, ys, xe - xs + 1, ye - ys + 1);

        if (m_url.isEmpty())

            download();

        emit updated(QRect(0, 0, width, height));

    }

    void render(QPainter *p, const QRect &rect) {

        for (int x = 0; x <= m_tilesRect.width(); ++x)

            for (int y = 0; y <= m_tilesRect.height(); ++y) {

                QPoint tp(x + m_tilesRect.left(), y + m_tilesRect.top());

                QRect box = tileRect(tp);

                if (rect.intersects(box)) {

                    if (m_tilePixmaps.contains(tp))

                        p->drawPixmap(box, m_tilePixmaps.value(tp));

                    else

                        p->drawPixmap(box, m_emptyTile);

                }

            }

    }

    void pan(const QPoint &delta) {

        QPointF dx = QPointF(delta) / qreal(tdim);

        QPointF center = tileForCoordinate(latitude, longitude, zoom) - dx;

        latitude = latitudeFromTile(center.y(), zoom);

        longitude = longitudeFromTile(center.x(), zoom);

        invalidate();

    }

private slots:

    void handleNetworkData(QNetworkReply *reply) {

        QImage img;

        QPoint tp = reply->request().attribute(QNetworkRequest::User).toPoint();

        QUrl url = reply->url();

        if (!reply->error())

            if (!img.load(reply, 0))

                img = QImage();

        reply->deleteLater();

        m_tilePixmaps[tp] = QPixmap::fromImage(img);

        if (img.isNull())

            m_tilePixmaps[tp] = m_emptyTile;

        emit updated(tileRect(tp));

        // purge unused spaces

        QRect bound = m_tilesRect.adjusted(-2, -2, 2, 2);

        foreach(QPoint tp, m_tilePixmaps.keys())

        if (!bound.contains(tp))

            m_tilePixmaps.remove(tp);

        download();

    }

    void download() {

        QPoint grab(0, 0);

        for (int x = 0; x <= m_tilesRect.width(); ++x)

            for (int y = 0; y <= m_tilesRect.height(); ++y) {

                QPoint tp = m_tilesRect.topLeft() + QPoint(x, y);

                if (!m_tilePixmaps.contains(tp)) {

                    grab = tp;

                    break;

                }

            }

        if (grab == QPoint(0, 0)) {

            m_url = QUrl();

            return;

        }

        QString path = "http://tile.openstreetmap.org/%1/%2/%3.png";

        m_url = QUrl(path.arg(zoom).arg(grab.x()).arg(grab.y()));

        QNetworkRequest request;

        request.setUrl(m_url);

        request.setRawHeader("User-Agent", "Nokia (Qt) Graphics Dojo 1.0");

        request.setAttribute(QNetworkRequest::User, QVariant(grab));

        m_manager.get(request);

    }

signals:

    void updated(const QRect &rect);

protected:

    QRect tileRect(const QPoint &tp) {

        QPoint t = tp - m_tilesRect.topLeft();

        int x = t.x() * tdim + m_offset.x();

        int y = t.y() * tdim + m_offset.y();

        return QRect(x, y, tdim, tdim);

    }

private:

    QPoint m_offset;

    QRect m_tilesRect;

    QPixmap m_emptyTile;

    QHash<QPoint, QPixmap> m_tilePixmaps;

    QNetworkAccessManager m_manager;

    QUrl m_url;

};

class LightMaps: public QWidget

{

    Q_OBJECT

public:

    LightMaps(QWidget *parent = 0)

            : QWidget(parent)

            , pressed(false)

            , snapped(false)

            , zoomed(false)

            , invert(false) {

        m_normalMap = new SlippyMap(this);

        m_largeMap = new SlippyMap(this);

        connect(m_normalMap, SIGNAL(updated(QRect)), SLOT(updateMap(QRect)));

        connect(m_largeMap, SIGNAL(updated(QRect)), SLOT(update()));

    }

    void setCenter(qreal lat, qreal lng) {

        m_normalMap->latitude = lat;

        m_normalMap->longitude = lng;

        m_normalMap->invalidate();

        m_largeMap->invalidate();

    }

public slots:

    void toggleNightMode() {

        invert = !invert;

        update();

    }

private slots:

    void updateMap(const QRect &r) {

        update(r);

    }

protected:

    void activateZoom() {

        zoomed = true;

        tapTimer.stop();

        m_largeMap->zoom = m_normalMap->zoom + 1;

        m_largeMap->width = m_normalMap->width * 2;

        m_largeMap->height = m_normalMap->height * 2;

        m_largeMap->latitude = m_normalMap->latitude;

        m_largeMap->longitude = m_normalMap->longitude;

        m_largeMap->invalidate();

        update();

    }

    void resizeEvent(QResizeEvent *) {

        m_normalMap->width = width();

        m_normalMap->height = height();

        m_normalMap->invalidate();

        m_largeMap->width = m_normalMap->width * 2;

        m_largeMap->height = m_normalMap->height * 2;

        m_largeMap->invalidate();

    }

    void paintEvent(QPaintEvent *event) {

        QPainter p;

        p.begin(this);

        m_normalMap->render(&p, event->rect());

        p.setPen(Qt::black);

#if defined(Q_OS_SYMBIAN)

        QFont font = p.font();

        font.setPixelSize(13);

        p.setFont(font);

#endif

        p.drawText(rect(),  Qt::AlignBottom | Qt::TextWordWrap,

                   "Map data CCBYSA 2009 OpenStreetMap.org contributors");

        p.end();

        if (zoomed) {

            int dim = qMin(width(), height());

            int magnifierSize = qMin(MAX_MAGNIFIER, dim * 2 / 3);

            int radius = magnifierSize / 2;

            int ring = radius - 15;

            QSize box = QSize(magnifierSize, magnifierSize);

            // reupdate our mask

            if (maskPixmap.size() != box) {

                maskPixmap = QPixmap(box);

                maskPixmap.fill(Qt::transparent);

                QRadialGradient g;

                g.setCenter(radius, radius);

                g.setFocalPoint(radius, radius);

                g.setRadius(radius);

                g.setColorAt(1.0, QColor(255, 255, 255, 0));

                g.setColorAt(0.5, QColor(128, 128, 128, 255));

                QPainter mask(&maskPixmap);

                mask.setRenderHint(QPainter::Antialiasing);

                mask.setCompositionMode(QPainter::CompositionMode_Source);

                mask.setBrush(g);

                mask.setPen(Qt::NoPen);

                mask.drawRect(maskPixmap.rect());

                mask.setBrush(QColor(Qt::transparent));

                mask.drawEllipse(g.center(), ring, ring);

                mask.end();

            }

            QPoint center = dragPos - QPoint(0, radius);

            center = center + QPoint(0, radius / 2);

            QPoint corner = center - QPoint(radius, radius);

            QPoint xy = center * 2 - QPoint(radius, radius);

            // only set the dimension to the magnified portion

            if (zoomPixmap.size() != box) {

                zoomPixmap = QPixmap(box);

                zoomPixmap.fill(Qt::lightGray);

            }

            if (true) {

                QPainter p(&zoomPixmap);

                p.translate(-xy);

                m_largeMap->render(&p, QRect(xy, box));

                p.end();

            }

            QPainterPath clipPath;

            clipPath.addEllipse(center, ring, ring);

            QPainter p(this);

            p.setRenderHint(QPainter::Antialiasing);

            p.setClipPath(clipPath);

            p.drawPixmap(corner, zoomPixmap);

            p.setClipping(false);

            p.drawPixmap(corner, maskPixmap);

            p.setPen(Qt::gray);

            p.drawPath(clipPath);

        }

        if (invert) {

            QPainter p(this);

            p.setCompositionMode(QPainter::CompositionMode_Difference);

            p.fillRect(event->rect(), Qt::white);

            p.end();

        }

    }

    void timerEvent(QTimerEvent *) {

        if (!zoomed)

            activateZoom();

        update();

    }

    void mousePressEvent(QMouseEvent *event) {

        if (event->buttons() != Qt::LeftButton)

            return;

        pressed = snapped = true;

        pressPos = dragPos = event->pos();

        tapTimer.stop();

        tapTimer.start(HOLD_TIME, this);

    }

    void mouseMoveEvent(QMouseEvent *event) {

        if (!event->buttons())

            return;

        if (!zoomed) {

            if (!pressed || !snapped) {

                QPoint delta = event->pos() - pressPos;

                pressPos = event->pos();

                m_normalMap->pan(delta);

                return;

            } else {

                const int threshold = 10;

                QPoint delta = event->pos() - pressPos;

                if (snapped) {

                    snapped &= delta.x() < threshold;

                    snapped &= delta.y() < threshold;

                    snapped &= delta.x() > -threshold;

                    snapped &= delta.y() > -threshold;

                }

                if (!snapped)

                    tapTimer.stop();

            }

        } else {

            dragPos = event->pos();

            update();

        }

    }

    void mouseReleaseEvent(QMouseEvent *) {

        zoomed = false;

        update();

    }

    void keyPressEvent(QKeyEvent *event) {

        if (!zoomed) {

            if (event->key() == Qt::Key_Left)

                m_normalMap->pan(QPoint(20, 0));

            if (event->key() == Qt::Key_Right)

                m_normalMap->pan(QPoint(-20, 0));

            if (event->key() == Qt::Key_Up)

                m_normalMap->pan(QPoint(0, 20));

            if (event->key() == Qt::Key_Down)

                m_normalMap->pan(QPoint(0, -20));

            if (event->key() == Qt::Key_Z || event->key() == Qt::Key_Select) {

                dragPos = QPoint(width() / 2, height() / 2);

                activateZoom();

            }

        } else {

            if (event->key() == Qt::Key_Z || event->key() == Qt::Key_Select) {

                zoomed = false;

                update();

            }

            QPoint delta(0, 0);

            if (event->key() == Qt::Key_Left)

                delta = QPoint(-15, 0);

            if (event->key() == Qt::Key_Right)

                delta = QPoint(15, 0);

            if (event->key() == Qt::Key_Up)

                delta = QPoint(0, -15);

            if (event->key() == Qt::Key_Down)

                delta = QPoint(0, 15);

            if (delta != QPoint(0, 0)) {

                dragPos += delta;

                update();

            }

        }

    }

private:

    SlippyMap *m_normalMap;

    SlippyMap *m_largeMap;

    bool pressed;

    bool snapped;

    QPoint pressPos;

    QPoint dragPos;

    QBasicTimer tapTimer;

    bool zoomed;

    QPixmap zoomPixmap;

    QPixmap maskPixmap;

    bool invert;

};

class MapZoom : public QMainWindow

{

    Q_OBJECT

private:

    LightMaps *map;

public:

    MapZoom(): QMainWindow(0) {

        map = new LightMaps(this);

        setCentralWidget(map);

        map->setFocus();

        QAction *osloAction = new QAction("&Oslo", this);

        QAction *berlinAction = new QAction("&Berlin", this);

        QAction *jakartaAction = new QAction("&Jakarta", this);

        QAction *nightModeAction = new QAction("Night Mode", this);

        nightModeAction->setCheckable(true);

        nightModeAction->setChecked(false);

        QAction *osmAction = new QAction("About OpenStreetMap", this);

        connect(osloAction, SIGNAL(triggered()), SLOT(chooseOslo()));

        connect(berlinAction, SIGNAL(triggered()), SLOT(chooseBerlin()));

        connect(jakartaAction, SIGNAL(triggered()), SLOT(chooseJakarta()));

        connect(nightModeAction, SIGNAL(triggered()), map, SLOT(toggleNightMode()));

        connect(osmAction, SIGNAL(triggered()), SLOT(aboutOsm()));

#if defined(Q_OS_SYMBIAN) || defined(Q_OS_WINCE_WM)

        menuBar()->addAction(osloAction);

        menuBar()->addAction(berlinAction);

        menuBar()->addAction(jakartaAction);

        menuBar()->addAction(nightModeAction);

        menuBar()->addAction(osmAction);

#else

        QMenu *menu = menuBar()->addMenu("&Options");

        menu->addAction(osloAction);

        menu->addAction(berlinAction);

        menu->addAction(jakartaAction);

        menu->addSeparator();

        menu->addAction(nightModeAction);

        menu->addAction(osmAction);

#endif