/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/*

 * This file is part of the LibreOffice project.

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/.

 *

 * This file incorporates work covered by the following license notice:

 *

 *   Licensed to the Apache Software Foundation (ASF) under one or more

 *   contributor license agreements. See the NOTICE file distributed

 *   with this work for additional information regarding copyright

 *   ownership. The ASF licenses this file to you under the Apache

 *   License, Version 2.0 (the "License"); you may not use this file

 *   except in compliance with the License. You may obtain a copy of

 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .

 */

#include <drawinglayer/geometry/viewinformation2d.hxx>

#include <drawinglayer/primitive2d/borderlineprimitive2d.hxx>

#include <drawinglayer/primitive2d/drawinglayer_primitivetypes2d.hxx>

#include <basegfx/polygon/b2dpolygon.hxx>

#include <drawinglayer/primitive2d/PolyPolygonColorPrimitive2D.hxx>

#include <drawinglayer/primitive2d/PolygonStrokePrimitive2D.hxx>

#include <drawinglayer/primitive2d/groupprimitive2d.hxx>

#include <rtl/math.hxx>

#include <algorithm>

#include <utility>

namespace drawinglayer::primitive2d

{

        BorderLine::BorderLine(

            const drawinglayer::attribute::LineAttribute& rLineAttribute,

            double fStartLeft,

            double fStartRight,

            double fEndLeft,

            double fEndRight)

        :   maLineAttribute(rLineAttribute),

            mfStartLeft(fStartLeft),

            mfStartRight(fStartRight),

            mfEndLeft(fEndLeft),

            mfEndRight(fEndRight),

            mbIsGap(false)

        {

        }

        BorderLine::BorderLine(

            double fWidth)

        :   maLineAttribute(basegfx::BColor(), fWidth),

            mfStartLeft(0.0),

            mfStartRight(0.0),

            mfEndLeft(0.0),

            mfEndRight(0.0),

            mbIsGap(true)

        {

        }

        BorderLine::~BorderLine()

        {

        }

        bool BorderLine::operator==(const BorderLine& rBorderLine) const

        {

            return getLineAttribute() == rBorderLine.getLineAttribute()

                && getStartLeft() == rBorderLine.getStartLeft()

                && getStartRight() == rBorderLine.getStartRight()

                && getEndLeft() == rBorderLine.getEndLeft()

                && getEndRight() == rBorderLine.getEndRight()

                && isGap() == rBorderLine.isGap();

        }

        // helper to add a centered, maybe stroked line primitive to rContainer

        static void addPolygonStrokePrimitive2D(

            Primitive2DContainer& rContainer,

            const basegfx::B2DPoint& rStart,

            const basegfx::B2DPoint& rEnd,

            const attribute::LineAttribute& rLineAttribute,

            const attribute::StrokeAttribute& rStrokeAttribute)

        {

            basegfx::B2DPolygon aPolygon;

            aPolygon.append(rStart);

            aPolygon.append(rEnd);

            if (rStrokeAttribute.isDefault())

            {

                rContainer.push_back(

                    new PolygonStrokePrimitive2D(

                        std::move(aPolygon),

                        rLineAttribute));

            }

            else

            {

                rContainer.push_back(

                    new PolygonStrokePrimitive2D(

                        std::move(aPolygon),

                        rLineAttribute,

                        rStrokeAttribute));

            }

        }

        double BorderLinePrimitive2D::getFullWidth() const

        {

            double fRetval(0.0);

            for(const auto& candidate : maBorderLines)

            {

                fRetval += candidate.getLineAttribute().getWidth();

            }

            return fRetval;

        }

        Primitive2DReference BorderLinePrimitive2D::create2DDecomposition(const geometry::ViewInformation2D& /*rViewInformation*/) const

        {

            if (getStart().equal(getEnd()) || getBorderLines().empty())

                return nullptr;

            // get data and vectors

            basegfx::B2DVector aVector(getEnd() - getStart());

            aVector.normalize();

            const basegfx::B2DVector aPerpendicular(basegfx::getPerpendicular(aVector));

            const double fFullWidth(getFullWidth());

            double fOffset(fFullWidth * -0.5);

            Primitive2DContainer aContainer;

            for(const auto& candidate : maBorderLines)

            {

                const double fWidth(candidate.getLineAttribute().getWidth());

                if(!candidate.isGap())

                {

                    const basegfx::B2DVector aDeltaY(aPerpendicular * (fOffset + (fWidth * 0.5)));

                    const basegfx::B2DPoint aStart(getStart() + aDeltaY);

                    const basegfx::B2DPoint aEnd(getEnd() + aDeltaY);

                    const bool bStartPerpendicular(rtl::math::approxEqual(candidate.getStartLeft(), candidate.getStartRight()));

                    const bool bEndPerpendicular(rtl::math::approxEqual(candidate.getEndLeft(), candidate.getEndRight()));

                    if(bStartPerpendicular && bEndPerpendicular)

                    {

                        // start and end extends lead to an edge perpendicular to the line, so we can just use

                        // a PolygonStrokePrimitive2D for representation

                        addPolygonStrokePrimitive2D(

                            aContainer,

                            aStart - (aVector * candidate.getStartLeft()),

                            aEnd + (aVector * candidate.getEndLeft()),

                            candidate.getLineAttribute(),

                            getStrokeAttribute());

                    }

                    else

                    {

                        // start and/or end extensions lead to a lineStart/End that is *not*

                        // perpendicular to the line itself

                        if(getStrokeAttribute().isDefault() || 0.0 == getStrokeAttribute().getFullDotDashLen())

                        {

                            // without stroke, we can simply represent that using a filled polygon

                            const basegfx::B2DVector aHalfLineOffset(aPerpendicular * (candidate.getLineAttribute().getWidth() * 0.5));

                            basegfx::B2DPolygon aPolygon;

                            aPolygon.append(aStart - aHalfLineOffset - (aVector * candidate.getStartLeft()));

                            aPolygon.append(aEnd - aHalfLineOffset + (aVector * candidate.getEndLeft()));

                            aPolygon.append(aEnd + aHalfLineOffset + (aVector * candidate.getEndRight()));

                            aPolygon.append(aStart + aHalfLineOffset - (aVector * candidate.getStartRight()));

                            aContainer.push_back(

                                new PolyPolygonColorPrimitive2D(

                                    basegfx::B2DPolyPolygon(aPolygon),

                                    candidate.getLineAttribute().getColor()));

                        }

                        else

                        {

                            // with stroke, we have a problem - a filled polygon would lose the

                            // stroke. Let's represent the start and/or end as triangles, the main

                            // line still as PolygonStrokePrimitive2D.

                            // Fill default line Start/End for stroke, so we need no adaptations in else paths

                            basegfx::B2DPoint aStrokeStart(aStart - (aVector * candidate.getStartLeft()));

                            basegfx::B2DPoint aStrokeEnd(aEnd + (aVector * candidate.getEndLeft()));

                            const basegfx::B2DVector aHalfLineOffset(aPerpendicular * (candidate.getLineAttribute().getWidth() * 0.5));

                            if(!bStartPerpendicular)

                            {

                                const double fMin(std::min(candidate.getStartLeft(), candidate.getStartRight()));

                                const double fMax(std::max(candidate.getStartLeft(), candidate.getStartRight()));

                                basegfx::B2DPolygon aPolygon;

                                // create a triangle with min/max values for LineStart and add

                                if(rtl::math::approxEqual(candidate.getStartLeft(), fMax))

                                {

                                    aPolygon.append(aStart - aHalfLineOffset - (aVector * candidate.getStartLeft()));

                                }

                                aPolygon.append(aStart - aHalfLineOffset - (aVector * fMin));

                                aPolygon.append(aStart + aHalfLineOffset - (aVector * fMin));

                                if(rtl::math::approxEqual(candidate.getStartRight(), fMax))

                                {

                                    aPolygon.append(aStart + aHalfLineOffset - (aVector * candidate.getStartRight()));

                                }

                                aContainer.push_back(

                                    new PolyPolygonColorPrimitive2D(

                                        basegfx::B2DPolyPolygon(aPolygon),

                                        candidate.getLineAttribute().getColor()));

                                // Adapt StrokeStart accordingly

                                aStrokeStart = aStart - (aVector * fMin);

                            }

                            if(!bEndPerpendicular)

                            {

                                const double fMin(std::min(candidate.getEndLeft(), candidate.getEndRight()));

                                const double fMax(std::max(candidate.getEndLeft(), candidate.getEndRight()));

                                basegfx::B2DPolygon aPolygon;

                                // create a triangle with min/max values for LineEnd and add

                                if(rtl::math::approxEqual(candidate.getEndLeft(), fMax))

                                {

                                    aPolygon.append(aEnd - aHalfLineOffset + (aVector * candidate.getEndLeft()));

                                }

                                if(rtl::math::approxEqual(candidate.getEndRight(), fMax))

                                {

                                    aPolygon.append(aEnd + aHalfLineOffset + (aVector * candidate.getEndRight()));

                                }

                                aPolygon.append(aEnd + aHalfLineOffset + (aVector * fMin));

                                aPolygon.append(aEnd - aHalfLineOffset + (aVector * fMin));

                                aContainer.push_back(

                                    new PolyPolygonColorPrimitive2D(

                                        basegfx::B2DPolyPolygon(aPolygon),

                                        candidate.getLineAttribute().getColor()));

                                // Adapt StrokeEnd accordingly

                                aStrokeEnd = aEnd + (aVector * fMin);

                            }

                            addPolygonStrokePrimitive2D(

                                aContainer,

                                aStrokeStart,

                                aStrokeEnd,

                                candidate.getLineAttribute(),

                                getStrokeAttribute());

                        }

                    }

                }

                fOffset += fWidth;

            }

            return new GroupPrimitive2D(std::move(aContainer));

        }

        bool BorderLinePrimitive2D::isHorizontalOrVertical(const geometry::ViewInformation2D& rViewInformation) const

        {

            if (!getStart().equal(getEnd()))

            {

                const basegfx::B2DHomMatrix& rOTVT = rViewInformation.getObjectToViewTransformation();

                const basegfx::B2DVector aVector(rOTVT * getEnd() - rOTVT * getStart());

                return basegfx::fTools::equalZero(aVector.getX()) || basegfx::fTools::equalZero(aVector.getY());

            }

            return false;

        }

        BorderLinePrimitive2D::BorderLinePrimitive2D(

            const basegfx::B2DPoint& rStart,

            const basegfx::B2DPoint& rEnd,

            std::vector< BorderLine >&& rBorderLines,

            drawinglayer::attribute::StrokeAttribute aStrokeAttribute)

        :   maStart(rStart),

            maEnd(rEnd),

            maBorderLines(std::move(rBorderLines)),

            maStrokeAttribute(std::move(aStrokeAttribute))

        {

        }

        bool BorderLinePrimitive2D::operator==(const BasePrimitive2D& rPrimitive) const

        {

            if(!BufferedDecompositionPrimitive2D::operator==(rPrimitive))

                return false;

            const BorderLinePrimitive2D& rCompare = static_cast<const BorderLinePrimitive2D&>(rPrimitive);

            return (getStart() == rCompare.getStart()

                    && getEnd() == rCompare.getEnd()

                    && getStrokeAttribute() == rCompare.getStrokeAttribute()

                    && getBorderLines() == rCompare.getBorderLines());

        }

        // provide unique ID

        sal_uInt32 BorderLinePrimitive2D::getPrimitive2DID() const

        {

            return PRIMITIVE2D_ID_BORDERLINEPRIMITIVE2D;

        }

        Primitive2DReference tryMergeBorderLinePrimitive2D(

            const BorderLinePrimitive2D* pCandidateA,

            const BorderLinePrimitive2D* pCandidateB)

        {

            assert(pCandidateA);

            assert(pCandidateB);

            // start of candidate has to match end of this

            if(!pCandidateA->getEnd().equal(pCandidateB->getStart()))

            {

                return Primitive2DReference();

            }

            // candidate A needs a length

            if(pCandidateA->getStart().equal(pCandidateA->getEnd()))

            {

                return Primitive2DReference();

            }

            // candidate B needs a length

            if(pCandidateB->getStart().equal(pCandidateB->getEnd()))

            {

                return Primitive2DReference();

            }

            // StrokeAttribute has to be equal

            if(!(pCandidateA->getStrokeAttribute() == pCandidateB->getStrokeAttribute()))

            {

                return Primitive2DReference();

            }

            // direction has to be equal -> cross product == 0.0

            const basegfx::B2DVector aVT(pCandidateA->getEnd() - pCandidateA->getStart());

            const basegfx::B2DVector aVC(pCandidateB->getEnd() - pCandidateB->getStart());

            if(aVC.cross(aVT) != 0)

            {

                return Primitive2DReference();

            }

            // number BorderLines has to be equal

            const size_t count(pCandidateA->getBorderLines().size());

            if(count != pCandidateB->getBorderLines().size())

            {

                return Primitive2DReference();

            }

            for(size_t a(0); a < count; a++)

            {

                const BorderLine& rBT(pCandidateA->getBorderLines()[a]);

                const BorderLine& rBC(pCandidateB->getBorderLines()[a]);

                // LineAttribute has to be the same

                if(!(rBC.getLineAttribute() == rBT.getLineAttribute()))

                {

                    return Primitive2DReference();

                }

                // isGap has to be the same

                if(rBC.isGap() != rBT.isGap())

                {

                    return Primitive2DReference();

                }

                if(rBT.isGap())

                {

                    // when gap, width has to be equal

                    if(!rtl::math::approxEqual(rBT.getLineAttribute().getWidth(), rBC.getLineAttribute().getWidth()))

                    {

                        return Primitive2DReference();

                    }

                }

                else

                {

                    // when not gap, the line extends have at least reach to the center ( > 0.0),

                    // else there is an extend usage. When > 0.0 they just overlap, no problem

                    if(rBT.getEndLeft() >= 0.0

                        && rBT.getEndRight() >= 0.0

                        && rBC.getStartLeft() >= 0.0

                        && rBC.getStartRight() >= 0.0)

                    {

                        // okay

                    }

                    else

                    {

                        return Primitive2DReference();

                    }

                }

            }

            // all conditions met, create merged primitive

            std::vector< BorderLine > aMergedBorderLines;

            for(size_t a(0); a < count; a++)

            {

                const BorderLine& rBT(pCandidateA->getBorderLines()[a]);

                const BorderLine& rBC(pCandidateB->getBorderLines()[a]);

                if(rBT.isGap())

                {

                    aMergedBorderLines.push_back(rBT);

                }

                else

                {

                    aMergedBorderLines.push_back(

                        BorderLine(

                            rBT.getLineAttribute(),

                            rBT.getStartLeft(), rBT.getStartRight(),

                            rBC.getEndLeft(), rBC.getEndRight()));

                }

            }

            return

                new BorderLinePrimitive2D(

                    pCandidateA->getStart(),

                    pCandidateB->getEnd(),

                    std::move(aMergedBorderLines),

                    pCandidateA->getStrokeAttribute());

        }

} // end of namespace

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */