/****************************************************************************
 Copyright (C) 2013 Henry van Merode. All rights reserved.
 Copyright (c) 2015-2016 Chukong Technologies Inc.
 Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.

 https://axmolengine.github.io/

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ****************************************************************************/

#include "extensions/Particle3D/ParticleSystem3D.h"
#include "extensions/Particle3D/PU/PUBeamRender.h"
#include "extensions/Particle3D/PU/PUParticleSystem3D.h"
#include "extensions/Particle3D/PU/PUUtil.h"
#include "extensions/Particle3D/PU/PUSimpleSpline.h"
#include "renderer/MeshCommand.h"
#include "renderer/Renderer.h"
#include "renderer/TextureCache.h"
#include "renderer/backend/ProgramState.h"
#include "base/Director.h"
#include "3d/MeshRenderer.h"
#include "3d/Mesh.h"
#include "2d/Camera.h"
#include <sstream>

NS_AX_BEGIN

// Constants
const bool PUBeamRender::DEFAULT_USE_VERTEX_COLOURS                               = false;
const size_t PUBeamRender::DEFAULT_MAX_ELEMENTS                                   = 10;
const float PUBeamRender::DEFAULT_UPDATE_INTERVAL                                 = 0.1f;
const float PUBeamRender::DEFAULT_DEVIATION                                       = 300;
const size_t PUBeamRender::DEFAULT_NUMBER_OF_SEGMENTS                             = 2;
const PUBillboardChain::TexCoordDirection PUBeamRender::DEFAULT_TEXTURE_DIRECTION = PUBillboardChain::TCD_V;

PUBeamRender* PUBeamRender::create(std::string_view texFile)
{
    auto br = new PUBeamRender();
    br->autorelease();
    br->_texFile = texFile;
    return br;
}

void PUBeamRender::render(Renderer* renderer, const Mat4& transform, ParticleSystem3D* particleSystem)
{
    const ParticlePool& particlePool = particleSystem->getParticlePool();
    if (!_isVisible || particlePool.empty() || !_billboardChain)
        return;

    Vec3 basePosition = static_cast<PUParticleSystem3D*>(_particleSystem)->getDerivedPosition();
    for (auto&& iter : particlePool.getActiveDataList())
    {
        auto particle   = static_cast<PUParticle3D*>(iter);
        auto visualData = static_cast<PUParticle3DBeamVisualData*>(particle->visualData);
        if (visualData)
        {
            Vec3 end = particle->position - basePosition;
            PUSimpleSpline spline;

            // Add points
            spline.addPoint(Vec3::ZERO);
            for (size_t numDev = 0; numDev < _numberOfSegments; ++numDev)
            {
                spline.addPoint(visualData->half[numDev]);
            }
            spline.addPoint(end);

            // Loop through all chain elements
            for (size_t j = 0; j < _maxChainElements; ++j)
            {
                PUBillboardChain::Element element = _billboardChain->getChainElement(visualData->chainIndex, j);

                // 1. Set the width of the chain if required
                if (particle->ownDimensions)
                {
                    element.width = _rendererScale.x * particle->width;
                }

                // 2. Set positions of the elements
                element.position = spline.interpolate((float)j / (float)_maxChainElements);

                // 3. Set the colour
                element.color = particle->color;

                // 4. Update
                _billboardChain->updateChainElement(visualData->chainIndex, j, element);
            }
            visualData->setVisible(true);
        }
    }

    _billboardChain->render(renderer, transform, particleSystem);
}

PUBeamRender::PUBeamRender()
    : _billboardChain(0)
    , _quota(0)
    , _useVertexColours(DEFAULT_USE_VERTEX_COLOURS)
    , _maxChainElements(DEFAULT_MAX_ELEMENTS)
    , _updateInterval(DEFAULT_UPDATE_INTERVAL)
    , _deviation(DEFAULT_DEVIATION)
    , _numberOfSegments(DEFAULT_NUMBER_OF_SEGMENTS)
    , _jump(false)
    , _texCoordDirection(DEFAULT_TEXTURE_DIRECTION)
{
    autoRotate = true;
}

PUBeamRender::~PUBeamRender()
{
    if (!_particleSystem)
        return;

    destroyAll();
}

void PUBeamRender::particleEmitted(PUParticleSystem3D* particleSystem, PUParticle3D* particle)
{
    if (!particle->visualData && !_visualData.empty() && particle->particleType == PUParticle3D::PT_VISUAL)
    {
        particle->visualData = _visualData.back();
        PUParticle3DBeamVisualData* beamRendererVisualData =
            static_cast<PUParticle3DBeamVisualData*>(particle->visualData);
        beamRendererVisualData->setVisible(true, _rendererScale.x * particleSystem->getDefaultWidth());  // PU 1.4
        _visualData.pop_back();
    }
}

void PUBeamRender::particleExpired(PUParticleSystem3D* /*particleSystem*/, PUParticle3D* particle)
{
    if (particle->visualData)
    {
        PUParticle3DBeamVisualData* beamRendererVisualData =
            static_cast<PUParticle3DBeamVisualData*>(particle->visualData);
        beamRendererVisualData->setVisible(false, 0);  // PU 1.4
        _visualData.emplace_back(beamRendererVisualData);
        particle->visualData = nullptr;
    }
}

//-----------------------------------------------------------------------
bool PUBeamRender::isUseVertexColours() const
{
    return _useVertexColours;
}
//-----------------------------------------------------------------------
void PUBeamRender::setUseVertexColours(bool useVertexColours)
{
    _useVertexColours = useVertexColours;
    if (!_billboardChain)
        return;

    _billboardChain->setUseVertexColours(_useVertexColours);
    _billboardChain->setUseTextureCoords(!_useVertexColours);
}
//-----------------------------------------------------------------------
size_t PUBeamRender::getMaxChainElements() const
{
    return _maxChainElements;
}
//-----------------------------------------------------------------------
void PUBeamRender::setMaxChainElements(size_t maxChainElements)
{
    _maxChainElements = maxChainElements;
}
//-----------------------------------------------------------------------
float PUBeamRender::getUpdateInterval() const
{
    return _updateInterval;
}
//-----------------------------------------------------------------------
void PUBeamRender::setUpdateInterval(float updateInterval)
{
    _updateInterval = updateInterval;
}
//-----------------------------------------------------------------------
float PUBeamRender::getDeviation() const
{
    return _deviation;
}
//-----------------------------------------------------------------------
void PUBeamRender::setDeviation(float deviation)
{
    _deviation = deviation;
}
//-----------------------------------------------------------------------
size_t PUBeamRender::getNumberOfSegments() const
{
    return _numberOfSegments;
}
//-----------------------------------------------------------------------
void PUBeamRender::setNumberOfSegments(size_t numberOfSegments)
{
    _numberOfSegments = numberOfSegments;
}
//-----------------------------------------------------------------------
bool PUBeamRender::isJump() const
{
    return _jump;
}
//-----------------------------------------------------------------------
void PUBeamRender::setJump(bool jump)
{
    _jump = jump;
}
//-----------------------------------------------------------------------
PUBillboardChain::TexCoordDirection PUBeamRender::getTexCoordDirection() const
{
    return _texCoordDirection;
}
//-----------------------------------------------------------------------
void PUBeamRender::setTexCoordDirection(PUBillboardChain::TexCoordDirection texCoordDirection)
{
    _texCoordDirection = texCoordDirection;
}
//-----------------------------------------------------------------------

void PUBeamRender::prepare()
{
    if (!_particleSystem)
        return;

    // Register itself to the technique
    if (_particleSystem)
    {
        // Although it is safe to assume that technique == mParentTechnique, use the mParentTechnique, because the
        // mParentTechnique is also used for unregistering.
        static_cast<PUParticleSystem3D*>(_particleSystem)->addListener(this);
    }

    _quota = _particleSystem->getParticleQuota();

    // Create BillboardChain
    std::stringstream ss;
    ss << this;
    _billboardChainName = "Beam" + ss.str();
    _billboardChain     = new PUBillboardChain(_billboardChainName, _texFile);
    _billboardChain->setDynamic(true);
    _billboardChain->setNumberOfChains(_quota);
    _billboardChain->setMaxChainElements(_maxChainElements);
    _billboardChain->setTextureCoordDirection(_texCoordDirection);
    setUseVertexColours(_useVertexColours);
    _billboardChain->setOtherTextureCoordRange(0.0f, 1.0f);
    _billboardChain->setDepthTest(_depthTest);
    _billboardChain->setDepthWrite(_depthWrite);

    // Create number of VisualData objects
    for (size_t i = 0; i < _quota; i++)
    {
        for (size_t j = 0; j < _maxChainElements; j++)
        {
            PUBillboardChain::Element element;
            element = PUBillboardChain::Element(
                Vec3::ZERO, _rendererScale.x * static_cast<PUParticleSystem3D*>(_particleSystem)->getDefaultWidth(),
                0.0f, Vec4::ONE, Quaternion::identity());  // V1.51
            _billboardChain->addChainElement(i, element);
        }

        PUParticle3DBeamVisualData* visualData = new PUParticle3DBeamVisualData(i, _billboardChain);
        for (size_t numDev = 0; numDev < _numberOfSegments; ++numDev)
        {
            // Initialise the positions
            visualData->half[numDev].setZero();
            visualData->destinationHalf[numDev].setZero();
        }
        _allVisualData.emplace_back(visualData);  // Managed by this renderer
        _visualData.emplace_back(visualData);     // Used to assign to a particle
    }
}

void PUBeamRender::unPrepare()
{
    destroyAll();
}

void PUBeamRender::updateRender(PUParticle3D* particle, float deltaTime, bool /*firstParticle*/)
{
    if (!particle->visualData)
        return;

    PUParticle3DBeamVisualData* beamRendererVisualData = static_cast<PUParticle3DBeamVisualData*>(particle->visualData);
    beamRendererVisualData->timeSinceLastUpdate -= deltaTime;

    if (beamRendererVisualData->timeSinceLastUpdate < 0)
    {

        Vec3 end = particle->position - static_cast<PUParticleSystem3D*>(_particleSystem)->getDerivedPosition();
        Vec3 perpendicular;
        float divide = (float)_numberOfSegments + 1.0f;
        for (size_t numDev = 0; numDev < _numberOfSegments; ++numDev)
        {
            Vec3::cross(end, Vec3(AXRANDOM_MINUS1_1(), AXRANDOM_MINUS1_1(), AXRANDOM_MINUS1_1()), &perpendicular);
            perpendicular.normalize();
            beamRendererVisualData->destinationHalf[numDev] =
                (((float)numDev + 1.0f) / divide) * end + Vec3(_rendererScale.x * _deviation * perpendicular.x,
                                                               _rendererScale.y * _deviation * perpendicular.y,
                                                               _rendererScale.z * _deviation * perpendicular.z);
        }
        beamRendererVisualData->timeSinceLastUpdate += _updateInterval;
    }

    Vec3 diff;
    for (size_t numDev = 0; numDev < _numberOfSegments; ++numDev)
    {
        if (_jump)
        {
            beamRendererVisualData->half[numDev] = beamRendererVisualData->destinationHalf[numDev];
        }
        else
        {
            diff = beamRendererVisualData->destinationHalf[numDev] - beamRendererVisualData->half[numDev];
            beamRendererVisualData->half[numDev] = beamRendererVisualData->half[numDev] + deltaTime * diff;
        }
    }
}

//-----------------------------------------------------------------------
void PUBeamRender::destroyAll()
{
    if (!_particleSystem || !_billboardChain)
        return;

    // Remove the listener
    static_cast<PUParticleSystem3D*>(_particleSystem)->removeListener(this);

    // Delete the BillboardChain
    AX_SAFE_DELETE(_billboardChain);

    // Delete the visual data
    std::vector<PUParticle3DBeamVisualData*>::const_iterator it;
    std::vector<PUParticle3DBeamVisualData*>::const_iterator itEnd = _allVisualData.end();
    for (it = _allVisualData.begin(); it != itEnd; ++it)
    {
        delete *it;
    }

    _allVisualData.clear();
    _visualData.clear();
}

PUBeamRender* PUBeamRender::clone()
{
    auto br = PUBeamRender::create(_texFile);
    copyAttributesTo(br);
    return br;
}

void PUBeamRender::copyAttributesTo(PUBeamRender* beamRender)
{
    PURender::copyAttributesTo(beamRender);
    beamRender->setUseVertexColours(_useVertexColours);
    beamRender->setMaxChainElements(_maxChainElements);
    beamRender->setUpdateInterval(_updateInterval);
    beamRender->setDeviation(_deviation);
    beamRender->setNumberOfSegments(_numberOfSegments);
    beamRender->setJump(_jump);
    beamRender->setTexCoordDirection(_texCoordDirection);
}

NS_AX_END