/************************************************************************
 **
 **  @file   vobjengine.cpp
 **  @author Roman Telezhynskyi <dismine(at)gmail.com>
 **  @date   12 12, 2014
 **
 **  @brief
 **  @copyright
 **  This source code is part of the Valentina project, a pattern making
 **  program, whose allow create and modeling patterns of clothing.
 **  Copyright (C) 2013-2015 Valentina project
 **  <https://gitlab.com/smart-pattern/valentina> All Rights Reserved.
 **
 **  Valentina 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.
 **
 **  Valentina 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 Valentina.  If not, see <http://www.gnu.org/licenses/>.
 **
 *************************************************************************/

#include "vobjengine.h"

#include <QByteArray>
#include <QFlag>
#include <QFlags>
#include <QIODevice>
#include <QLatin1Char>
#include <QMessageLogger>
#include <QPaintEngineState>
#include <QPainterPath>
#include <QPointF>
#include <QString>
#include <QTextStream>
#include <QVector>
#include <QtDebug>
#include <QtMath>

#include "../vmisc/defglobal.h"

#if QT_VERSION < QT_VERSION_CHECK(5, 14, 0)
#include "../vmisc/backport/text.h"
#endif

// Header <ciso646> is removed in C++20.
#if __cplusplus <= 201703L
#include <ciso646> // and, not, or
#endif

class QPaintDevice;
class QPixmap;
class QPoint;
class QPointF;
class QPolygonF;
class QRectF;

//---------------------------------------------------------------------------------------------------------------------
static inline auto svgEngineFeatures() -> QPaintEngine::PaintEngineFeatures
{
    QT_WARNING_PUSH
    QT_WARNING_DISABLE_CLANG("-Wsign-conversion")
    // cppcheck-suppress unknownMacro
    QT_WARNING_DISABLE_INTEL(68)
    QT_WARNING_DISABLE_INTEL(2022)

    return {QPaintEngine::AllFeatures & ~QPaintEngine::PatternBrush & ~QPaintEngine::PerspectiveTransform &
            ~QPaintEngine::ConicalGradientFill & ~QPaintEngine::PorterDuff};

    QT_WARNING_POP
}

//---------------------------------------------------------------------------------------------------------------------
VObjEngine::VObjEngine()
  : QPaintEngine(svgEngineFeatures()),
    stream(),
    globalPointsCount(0),
    outputDevice(),
    planeCount(0),
    size(),
    resolution(96),
    matrix()
{
    for (int i = 0; i < MAX_POINTS; i++)
    {
        points[i].x = 0;
        points[i].y = 0;
    }
}

#if defined(Q_CC_INTEL)
#pragma warning(pop)
#endif

//---------------------------------------------------------------------------------------------------------------------
auto VObjEngine::begin(QPaintDevice *pdev) -> bool
{
    Q_UNUSED(pdev)
    if (outputDevice.isNull())
    {
        qWarning("VObjEngine::begin(), no output device");
        return false;
    }
    if (outputDevice->isOpen() == false)
    {
        if (outputDevice->open(QIODevice::WriteOnly | QIODevice::Text | QIODevice::Truncate) == false)
        {
            qWarning("VObjEngine::begin(), could not open output device: '%s'",
                     qPrintable(outputDevice->errorString()));
            return false;
        }
    }
    else if (outputDevice->isWritable() == false)
    {
        qWarning("VObjEngine::begin(), could not write to read-only output device: '%s'",
                 qPrintable(outputDevice->errorString()));
        return false;
    }

    if (size.isValid() == false)
    {
        qWarning() << "VObjEngine::begin(), size is not valid";
        return false;
    }

    stream = QSharedPointer<QTextStream>(new QTextStream(outputDevice.data()));
    *stream << "# Valentina OBJ File" << Qt::endl;
    *stream << "# smart-pattern.com.ua/" << Qt::endl;
    return true;
}

//---------------------------------------------------------------------------------------------------------------------
auto VObjEngine::end() -> bool
{
    stream.reset();
    return true;
}

//---------------------------------------------------------------------------------------------------------------------
// cppcheck-suppress unusedFunction
void VObjEngine::updateState(const QPaintEngineState &state)
{
    QPaintEngine::DirtyFlags flags = state.state();

    // always stream full gstate, which is not required, but...
    flags |= QPaintEngine::AllDirty;

    if (flags & QPaintEngine::DirtyTransform)
    {
        matrix = state.transform(); // Save new matrix for moving paths
    }
}

//---------------------------------------------------------------------------------------------------------------------
void VObjEngine::drawPath(const QPainterPath &path)
{
    QPolygonF polygon = path.toFillPolygon(matrix);
    polygon = MakePointsUnique(polygon); // Points must be unique
    if (polygon.size() < 3)
    {
        return;
    }

    qint64 sq = Square(polygon);

    ++planeCount;
    *stream << "o Plane." << QString("%1").arg(planeCount, 3, 10, QLatin1Char('0')) << Qt::endl;

    quint32 num_points = 0;

    for (auto &p : polygon)
    {
        if (num_points < MAX_POINTS)
        {
            points[num_points].x = p.x();
            points[num_points].y = p.y();
            num_points++;
        }
    }

    int offset = 0;
    delaunay2d_t *res = delaunay2d_from(points, num_points); // Calculate faces

    QPointF pf[MAX_POINTS];
    // cppcheck-suppress unreadVariable
    bool skipFace = false; // Need skip first face

    for (quint32 i = 0; i < res->num_faces; i++)
    {
        if (offset == 0)
        {
            skipFace = true;
        }
        else
        {
            skipFace = false;
        }
        int num_verts = static_cast<int>(res->faces[offset]);
        offset++;
        for (int j = 0; j < num_verts; j++)
        {
            int p0 = static_cast<int>(res->faces[offset + j]);
            pf[j] = QPointF(points[p0].x, points[p0].y);
        }
        if (skipFace == false)
        {
            QPolygonF face;
            for (int ind = 0; ind < num_verts; ind++)
            {
                face << QPointF(pf[ind]);
            }
            QPolygonF united = polygon.united(face);
            qint64 sqUnited = Square(united);
            if (sqUnited <= sq)
            { // This face incide our base polygon.
                drawPolygon(pf, num_verts, QPaintEngine::OddEvenMode);
            }
        }
        offset += num_verts;
    }

    delaunay2d_release(res); // Don't forget release data
    *stream << "s off" << Qt::endl;
}

//---------------------------------------------------------------------------------------------------------------------
void VObjEngine::drawPolygon(const QPointF *points, int pointCount, PolygonDrawMode mode)
{
    Q_UNUSED(mode)

    drawPoints(points, pointCount);
    *stream << "f";

    for (int i = 0; i < pointCount; ++i)
    {
        *stream << QString(" %1").arg(static_cast<int>(globalPointsCount) - pointCount + i + 1);
    }
    *stream << Qt::endl;
}

//---------------------------------------------------------------------------------------------------------------------
void VObjEngine::drawPolygon(const QPoint *points, int pointCount, QPaintEngine::PolygonDrawMode mode)
{
    QPaintEngine::drawPolygon(points, pointCount, mode);
}

//---------------------------------------------------------------------------------------------------------------------
auto VObjEngine::type() const -> QPaintEngine::Type
{
    return QPaintEngine::User;
}

//---------------------------------------------------------------------------------------------------------------------
void VObjEngine::drawPoints(const QPointF *points, int pointCount)
{
    for (int i = 0; i < pointCount; ++i)
    {
        qreal x = ((points[i].x() - 0) / qFloor(size.width() / 2.0)) - 1.0;
        qreal y = (((points[i].y() - 0) / qFloor(size.width() / 2.0)) - 1.0) * -1;

        *stream << "v"
                << " " << QString::number(x, 'f', 6) << " " << QString::number(y, 'f', 6) << " "
                << "0.000000" << Qt::endl;
        ++globalPointsCount;
    }
}

//---------------------------------------------------------------------------------------------------------------------
void VObjEngine::drawPoints(const QPoint *points, int pointCount)
{
    QPaintEngine::drawPoints(points, pointCount);
}

//---------------------------------------------------------------------------------------------------------------------
// cppcheck-suppress unusedFunction
void VObjEngine::drawPixmap(const QRectF &r, const QPixmap &pm, const QRectF &sr)
{
    Q_UNUSED(r)
    Q_UNUSED(pm)
    Q_UNUSED(sr)
}

//---------------------------------------------------------------------------------------------------------------------
auto VObjEngine::getSize() const -> QSize
{
    return size;
}

//---------------------------------------------------------------------------------------------------------------------
void VObjEngine::setSize(const QSize &value)
{
    Q_ASSERT(not isActive());
    size = value;
}

//---------------------------------------------------------------------------------------------------------------------
auto VObjEngine::getOutputDevice() const -> QIODevice *
{
    return outputDevice.data();
}

//---------------------------------------------------------------------------------------------------------------------
void VObjEngine::setOutputDevice(QIODevice *value)
{
    Q_ASSERT(not isActive());
    outputDevice.reset(value);
}

//---------------------------------------------------------------------------------------------------------------------
auto VObjEngine::getResolution() const -> int
{
    return resolution;
}

//---------------------------------------------------------------------------------------------------------------------
void VObjEngine::setResolution(int value)
{
    Q_ASSERT(not isActive());
    resolution = value;
}

//---------------------------------------------------------------------------------------------------------------------
auto VObjEngine::MakePointsUnique(const QPolygonF &polygon) const -> QPolygonF
{
    QVector<QPointF> set;
    QPolygonF uniquePolygon;
    for (auto p : polygon)
    {
        if (set.contains(p) == false)
        {
            set.append(p);
            uniquePolygon.append(p);
        }
    }
    return uniquePolygon;
}

//---------------------------------------------------------------------------------------------------------------------
auto VObjEngine::Square(const QPolygonF &poly) const -> qint64
{
    QVector<qreal> x;
    QVector<qreal> y;

    vsizetype n = poly.count();
    qreal s, res = 0;
    qint64 sq = 0;

    for (int i = 0; i < n; i++)
    {
        x.append(poly.at(i).x());
        y.append(poly.at(i).y());
    }

    // Calculation a polygon area through the sum of the areas of trapezoids
    for (int i = 0; i < n; i++)
    {
        if (i == 0)
        {
            s = x.at(i) * (y.at(n - 1) - y.at(i + 1)); // if i == 0, then y[i-1] replace on y[n-1]
            res += s;
        }
        else
        {
            if (i == n - 1)
            {
                s = x.at(i) * (y.at(i - 1) - y.at(0)); // if i == n-1, then y[i+1] replace on y[0]
                res += s;
            }
            else
            {
                s = x.at(i) * (y.at(i - 1) - y.at(i + 1));
                res += s;
            }
        }
    }
    sq = qFloor(qAbs(res / 2.0));
    return sq;
}