//    Copyright (C) 2021-2024 Jakub Melka
//
//    This file is part of PDF4QT.
//
//    PDF4QT is free software: you can redistribute it and/or modify
//    it under the terms of the GNU Lesser General Public License as published by
//    the Free Software Foundation, either version 3 of the License, or
//    with the written consent of the copyright owner, any later version.
//
//    PDF4QT 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 Lesser General Public License for more details.
//
//    You should have received a copy of the GNU Lesser General Public License
//    along with PDF4QT. If not, see <https://www.gnu.org/licenses/>.

#include "pdfpainterutils.h"
#include "pdfpagecontentprocessor.h"

#include <QPainterPath>
#include <QFontMetrics>

#include "pdfdbgheap.h"

namespace pdf
{

QRect PDFPainterHelper::drawBubble(QPainter* painter, QPoint point, QColor color, QString text, Qt::Alignment alignment)
{
    QFontMetrics fontMetrics = painter->fontMetrics();

    const int lineSpacing = fontMetrics.lineSpacing();
    const int bubbleHeight = lineSpacing* 2;
    const int bubbleWidth = lineSpacing + fontMetrics.horizontalAdvance(text);

    QRect rectangle(point, QSize(bubbleWidth, bubbleHeight));

    if (alignment.testFlag(Qt::AlignVCenter))
    {
        rectangle.translate(0, -rectangle.height() / 2);
    }
    else if (alignment.testFlag(Qt::AlignTop))
    {
        rectangle.translate(0, -rectangle.height());
    }

    if (alignment.testFlag(Qt::AlignHCenter))
    {
        rectangle.translate(-rectangle.width() / 2, 0);
    }
    else if (alignment.testFlag(Qt::AlignLeft))
    {
        rectangle.translate(-rectangle.width(), 0);
    }

    PDFPainterStateGuard guard(painter);
    painter->setRenderHint(QPainter::Antialiasing);
    painter->setPen(Qt::NoPen);
    painter->setBrush(QBrush(color));
    painter->drawRoundedRect(rectangle, rectangle.height() / 2, rectangle.height() / 2, Qt::AbsoluteSize);
    painter->setPen(Qt::black);
    painter->drawText(rectangle, Qt::AlignCenter, text);

    return rectangle;
}

QPen PDFPainterHelper::createPenFromState(const PDFPageContentProcessorState* graphicState, double alpha)
{
    QColor color = graphicState->getStrokeColor();
    if (color.isValid())
    {
        color.setAlphaF(alpha);
        const PDFReal lineWidth = graphicState->getLineWidth();
        Qt::PenCapStyle penCapStyle = graphicState->getLineCapStyle();
        Qt::PenJoinStyle penJoinStyle = graphicState->getLineJoinStyle();
        const PDFLineDashPattern& lineDashPattern = graphicState->getLineDashPattern();
        const PDFReal mitterLimit = graphicState->getMitterLimit();

        QPen pen(color);

        pen.setWidthF(lineWidth);
        pen.setCapStyle(penCapStyle);
        pen.setJoinStyle(penJoinStyle);
        pen.setMiterLimit(mitterLimit);

        if (lineDashPattern.isSolid())
        {
            pen.setStyle(Qt::SolidLine);
        }
        else
        {
            pen.setStyle(Qt::CustomDashLine);
            pen.setDashPattern(lineDashPattern.createForQPen(pen.widthF()));
            pen.setDashOffset(lineDashPattern.getDashOffset());
        }

        return pen;
    }
    else
    {
        return QPen(Qt::NoPen);
    }
}

QBrush PDFPainterHelper::createBrushFromState(const PDFPageContentProcessorState* graphicState, double alpha)
{
    QColor color = graphicState->getFillColor();
    if (color.isValid())
    {
        color.setAlphaF(alpha);
        return QBrush(color, Qt::SolidPattern);
    }
    else
    {
        return QBrush(Qt::NoBrush);
    }
}

PDFTransformationDecomposition PDFPainterHelper::decomposeTransform(const QTransform& transform)
{
    PDFTransformationDecomposition result;

    const qreal m11 = transform.m11();
    const qreal m12 = transform.m12();
    const qreal m21 = transform.m21();
    const qreal m22 = transform.m22();

    const qreal dx = transform.dx();
    const qreal dy = transform.dy();

    const qreal sx = std::sqrt(m11 * m11 + m21 * m21);
    const qreal phi = std::atan2(m21, m11);
    const qreal msy = m12 * std::cos(phi) + m22 * std::sin(phi);
    const qreal sy = -m12 * std::sin(phi) + m22 * std::cos(phi);

    result.rotationAngle = phi;
    result.scaleX = sx;
    result.scaleY = sy;

    if (!qFuzzyIsNull(sy))
    {
        result.shearFactor = msy / sy;
    }
    else
    {
        result.shearFactor = 0.0;
    }

    result.translateX = dx;
    result.translateY = dy;

    return result;
}

QTransform PDFPainterHelper::composeTransform(const PDFTransformationDecomposition& decomposition)
{
    const qreal s = std::sin(decomposition.rotationAngle);
    const qreal c = std::cos(decomposition.rotationAngle);

    const qreal m = decomposition.shearFactor;
    const qreal sx = decomposition.scaleX;
    const qreal sy = decomposition.scaleY;
    const qreal dx = decomposition.translateX;
    const qreal dy = decomposition.translateY;

    const qreal m11 = sx * c;
    const qreal m12 = sy * m * c - sy * s;
    const qreal m21 = sx * s;
    const qreal m22 = sy * m * s + sy * c;

    return QTransform(m11, m12, m21, m22, dx, dy);
}

}   // namespace pdf