/*

  Copyright © 2018 Hasan Yavuz Özderya

  This file is part of serialplot.

  serialplot 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 3 of the License, or

  (at your option) any later version.

  serialplot 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 serialplot.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "zoomer.h"

#include <qwt_plot.h>

#include <QPen>

#include <QMouseEvent>

#include <QtMath>

static const int VALUE_POINT_DIAM = 4;

Zoomer::Zoomer(QWidget* widget, const Stream* stream, bool doReplot) :

    ScrollZoomer(widget)

{

    is_panning = false;

    _stream = stream;

    setTrackerMode(AlwaysOn);

    // set corner widget between the scrollbars with default background color

    auto cornerWidget = new QWidget();

    auto bgColor = cornerWidget->palette().color(QPalette::Window).name();

    auto styleSheet = QString("background-color:%1;").arg(bgColor);

    cornerWidget->setStyleSheet(styleSheet);

    ScrollZoomer::setCornerWidget(cornerWidget);

}

void Zoomer::zoom(int up)

{

    ScrollZoomer::zoom(up);

    if(zoomRectIndex() == 0)

    {

        emit unzoomed();

    }

}

void Zoomer::zoom( const QRectF & rect)

{

    // set the zoom base when user zooms in to first level

    if (zoomRectIndex() == 0)

    {

        this->setZoomBase(false);

    }

    ScrollZoomer::zoom(rect);

}

QwtText Zoomer::trackerTextF(const QPointF& pos) const

{

    QwtText b = ScrollZoomer::trackerTextF(pos);

    const QPolygon pa = selection();

    if (!isActive() || pa.count() < 2)

    {

        return b;

    }

    if (pa.count() < 2)

    {

        return QRegion();

    }

    const QRect r = QRect(pa.first(), pa.last()).normalized().adjusted(0, 0, 1, 1);

    return QRegion(r);

}

void Zoomer::drawTracker(QPainter* painter) const

{

    if (isActive())

    {

        QwtPlotZoomer::drawTracker(painter);

    }

    else if (_stream != nullptr && _stream->numChannels())

    {

        drawValues(painter);

    }

}

void Zoomer::drawValues(QPainter* painter) const

{

    painter->save();

    double x = invTransform(trackerPosition()).x();

    auto values = findValues(x);

    // draw vertical line

    auto linePen = QPen(Qt::DotLine);

    linePen.setColor(Qt::white);

    painter->setPen(linePen);

    const QRect pRect = pickArea().boundingRect().toRect();

    int px = trackerPosition().x();

    painter->drawLine(px, pRect.top(), px, pRect.bottom());

    // draw sample values

    for (int ci = 0; ci < values.size(); ci++)

    {

        double val = values[ci];

        if (!std::isnan(val))

        {

            auto p = transform(QPointF(x, val));

            painter->setBrush(_stream->channel(ci)->color());

            painter->setPen(Qt::NoPen);

            painter->drawEllipse(p, VALUE_POINT_DIAM, VALUE_POINT_DIAM);

            painter->setPen(Qt::white);

        }

    }

    painter->restore();

}

QVector<double> Zoomer::findValues(double x) const

{

    // TODO: process only channel(s) of this plot

    unsigned nc = _stream->numChannels();

    QVector<double> r(nc);

    for (unsigned ci = 0; ci < nc; ci++)

    {

        auto chan = _stream->channel(ci);

        double val = chan->findValue(x);

        r[ci] = val;

    }

    return r;

}

QRect Zoomer::trackerRect(const QFont& font) const

{

    if (isActive())

    {

        return QwtPlotZoomer::trackerRect(font);

    }

    else

    {

        return valueTrackerRect(font);

    }

}

QRect Zoomer::valueTrackerRect(const QFont& font) const

{

    // TODO: consider using actual tracker values for width calculation

    const int textWidth = qCeil(QwtText("-8.8888888").textSize(font).width());

    const int x = trackerPosition().x() - VALUE_POINT_DIAM;

    const auto pickRect = pickArea().boundingRect();

    return QRect(x, pickRect.y(), width, pickRect.height());

}

void Zoomer::widgetMousePressEvent(QMouseEvent* mouseEvent)

{

    if (mouseEvent->modifiers() & Qt::ControlModifier)

    {

        is_panning = true;

        parentWidget()->setCursor(Qt::ClosedHandCursor);

        pan_point = invTransform(mouseEvent->pos());

    }

    else

    {

        ScrollZoomer::widgetMousePressEvent(mouseEvent);

    }

}

void Zoomer::widgetMouseMoveEvent(QMouseEvent* mouseEvent)

{

    if (is_panning)

    {

        auto cur_point = invTransform(mouseEvent->pos());

        auto delta = cur_point - pan_point;

        moveBy(-delta.x(), -delta.y());

        pan_point = invTransform(mouseEvent->pos());

    }

    else

    {

        ScrollZoomer::widgetMouseMoveEvent(mouseEvent);

    }

}

void Zoomer::widgetMouseReleaseEvent(QMouseEvent* mouseEvent)

{

    if (is_panning)

    {

        is_panning = false;

        parentWidget()->setCursor(Qt::CrossCursor);

    }

    else

    {

        ScrollZoomer::widgetMouseReleaseEvent(mouseEvent);

    }

}