/****************************************************************************
**
** Copyright (C) 2015 Klaralvdalens Datakonsult AB (KDAB).
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt3D module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL-EXCEPT$
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** GNU General Public License Usage
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** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
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****************************************************************************/

#include <QtTest/QTest>
#include <Qt3DRender/private/shader_p.h>
#include <Qt3DRender/qshaderprogram.h>
#include <Qt3DRender/private/nodemanagers_p.h>
#include <Qt3DRender/private/renderer_p.h>
#include <Qt3DRender/private/qrenderaspect_p.h>
#include <Qt3DRender/qrenderaspect.h>
#include <Qt3DRender/private/geometryrenderermanager_p.h>
#include <Qt3DRender/private/buffermanager_p.h>
#include <Qt3DRender/private/geometryrenderer_p.h>
#include <Qt3DRender/private/geometry_p.h>
#include <Qt3DRender/private/buffer_p.h>
#include <Qt3DRender/private/attribute_p.h>
#include <Qt3DRender/private/triangleboundingvolume_p.h>
#include <Qt3DRender/private/trianglesextractor_p.h>
#include <Qt3DRender/qattribute.h>
#include <Qt3DRender/qbuffer.h>
#include <Qt3DRender/qgeometry.h>
#include <Qt3DRender/qgeometryrenderer.h>
#include <Qt3DCore/private/qnodevisitor_p.h>

Qt3DRender::QGeometryRenderer *customIndexedGeometryRenderer()
{
    Qt3DRender::QGeometryRenderer *customMeshRenderer = new Qt3DRender::QGeometryRenderer;
    Qt3DRender::QGeometry *customGeometry = new Qt3DRender::QGeometry(customMeshRenderer);

    Qt3DRender::QBuffer *vertexDataBuffer = new Qt3DRender::QBuffer(Qt3DRender::QBuffer::VertexBuffer, customGeometry);
    Qt3DRender::QBuffer *indexDataBuffer = new Qt3DRender::QBuffer(Qt3DRender::QBuffer::IndexBuffer, customGeometry);

    // vec3 for position
    // vec3 for colors
    // vec3 for normals

    /*          2
               /|\
              / | \
             / /3\ \
             0/___\ 1
    */

    // 4 distinct vertices
    QByteArray vertexBufferData;
    vertexBufferData.resize(4 * (3 + 3 + 3) * sizeof(float));

    // Vertices
    QVector3D v0(-1.0f, 0.0f, -1.0f);
    QVector3D v1(1.0f, 0.0f, -1.0f);
    QVector3D v2(0.0f, 1.0f, 0.0f);
    QVector3D v3(0.0f, 0.0f, 1.0f);

    // Faces Normals
    QVector3D n023 = QVector3D::normal(v0, v2, v3);
    QVector3D n012 = QVector3D::normal(v0, v1, v2);
    QVector3D n310 = QVector3D::normal(v3, v1, v0);
    QVector3D n132 = QVector3D::normal(v1, v3, v2);

    // Vector Normals
    QVector3D n0 = QVector3D(n023 + n012 + n310).normalized();
    QVector3D n1 = QVector3D(n132 + n012 + n310).normalized();
    QVector3D n2 = QVector3D(n132 + n012 + n023).normalized();
    QVector3D n3 = QVector3D(n132 + n310 + n023).normalized();

    // Colors
    QVector3D red(1.0f, 0.0f, 0.0f);
    QVector3D green(0.0f, 1.0f, 0.0f);
    QVector3D blue(0.0f, 0.0f, 1.0f);
    QVector3D white(1.0f, 1.0f, 1.0f);

    QVector<QVector3D> vertices = QVector<QVector3D>()
            << v0 << n0 << red
            << v1 << n1 << blue
            << v2 << n2 << green
            << v3 << n3 << white;

    float *rawVertexArray = reinterpret_cast<float *>(vertexBufferData.data());
    int idx = 0;

    Q_FOREACH (const QVector3D &v, vertices) {
        rawVertexArray[idx++] = v.x();
        rawVertexArray[idx++] = v.y();
        rawVertexArray[idx++] = v.z();
    }

    // Indices (12)
    QByteArray indexBufferData;
    indexBufferData.resize(4 * 3 * sizeof(ushort));
    ushort *rawIndexArray = reinterpret_cast<ushort *>(indexBufferData.data());

    // Front
    rawIndexArray[0] = 0;
    rawIndexArray[1] = 1;
    rawIndexArray[2] = 2;
    // Bottom
    rawIndexArray[3] = 3;
    rawIndexArray[4] = 1;
    rawIndexArray[5] = 0;
    // Left
    rawIndexArray[6] = 0;
    rawIndexArray[7] = 2;
    rawIndexArray[8] = 3;
    // Right
    rawIndexArray[9] = 1;
    rawIndexArray[10] = 3;
    rawIndexArray[11] = 2;

    vertexDataBuffer->setData(vertexBufferData);
    indexDataBuffer->setData(indexBufferData);

    // Attributes
    Qt3DRender::QAttribute *positionAttribute = new Qt3DRender::QAttribute();
    positionAttribute->setAttributeType(Qt3DRender::QAttribute::VertexAttribute);
    positionAttribute->setBuffer(vertexDataBuffer);
    positionAttribute->setDataType(Qt3DRender::QAttribute::Float);
    positionAttribute->setDataSize(3);
    positionAttribute->setByteOffset(0);
    positionAttribute->setByteStride(9 * sizeof(float));
    positionAttribute->setCount(4);
    positionAttribute->setName(Qt3DRender::QAttribute::defaultPositionAttributeName());

    Qt3DRender::QAttribute *normalAttribute = new Qt3DRender::QAttribute();
    normalAttribute->setAttributeType(Qt3DRender::QAttribute::VertexAttribute);
    normalAttribute->setBuffer(vertexDataBuffer);
    normalAttribute->setDataType(Qt3DRender::QAttribute::Float);
    normalAttribute->setDataSize(3);
    normalAttribute->setByteOffset(3 * sizeof(float));
    normalAttribute->setByteStride(9 * sizeof(float));
    normalAttribute->setCount(4);
    normalAttribute->setName(Qt3DRender::QAttribute::defaultNormalAttributeName());

    Qt3DRender::QAttribute *colorAttribute = new Qt3DRender::QAttribute();
    colorAttribute->setAttributeType(Qt3DRender::QAttribute::VertexAttribute);
    colorAttribute->setBuffer(vertexDataBuffer);
    colorAttribute->setDataType(Qt3DRender::QAttribute::Float);
    colorAttribute->setDataSize(3);
    colorAttribute->setByteOffset(6 * sizeof(float));
    colorAttribute->setByteStride(9 * sizeof(float));
    colorAttribute->setCount(4);
    colorAttribute->setName(Qt3DRender::QAttribute::defaultColorAttributeName());

    Qt3DRender::QAttribute *indexAttribute = new Qt3DRender::QAttribute();
    indexAttribute->setAttributeType(Qt3DRender::QAttribute::IndexAttribute);
    indexAttribute->setBuffer(indexDataBuffer);
    indexAttribute->setDataType(Qt3DRender::QAttribute::UnsignedShort);
    indexAttribute->setDataSize(1);
    indexAttribute->setByteOffset(0);
    indexAttribute->setByteStride(0);
    indexAttribute->setCount(12);

    customGeometry->addAttribute(positionAttribute);
    customGeometry->addAttribute(normalAttribute);
    customGeometry->addAttribute(colorAttribute);
    customGeometry->addAttribute(indexAttribute);

    customMeshRenderer->setInstanceCount(1);
    customMeshRenderer->setBaseVertex(0);
    customMeshRenderer->setBaseInstance(0);
    customMeshRenderer->setPrimitiveType(Qt3DRender::QGeometryRenderer::Triangles);
    customMeshRenderer->setGeometry(customGeometry);
    // 4 faces of 3 points
    customMeshRenderer->setPrimitiveCount(12);

    return customMeshRenderer;
}

Qt3DRender::QGeometryRenderer *customNonIndexedGeometryRenderer()
{
    Qt3DRender::QGeometryRenderer *customMeshRenderer = new Qt3DRender::QGeometryRenderer;
    Qt3DRender::QGeometry *customGeometry = new Qt3DRender::QGeometry(customMeshRenderer);

    Qt3DRender::QBuffer *vertexDataBuffer = new Qt3DRender::QBuffer(Qt3DRender::QBuffer::VertexBuffer, customGeometry);

    // vec3 for position
    // vec3 for colors
    // vec3 for normals

    /*          2
               /|\
              / | \
             / /3\ \
             0/___\ 1
    */

    // 12 distinct vertices formaing 4 triangles
    QByteArray vertexBufferData;
    vertexBufferData.resize(4 * 3 * (3 + 3 + 3) * sizeof(float));

    // Vertices
    QVector3D v0(-1.0f, 0.0f, -1.0f);
    QVector3D v1(1.0f, 0.0f, -1.0f);
    QVector3D v2(0.0f, 1.0f, 0.0f);
    QVector3D v3(0.0f, 0.0f, 1.0f);

    // Faces Normals
    QVector3D n023 = QVector3D::normal(v0, v2, v3);
    QVector3D n012 = QVector3D::normal(v0, v1, v2);
    QVector3D n310 = QVector3D::normal(v3, v1, v0);
    QVector3D n132 = QVector3D::normal(v1, v3, v2);

    // Vector Normals
    QVector3D n0 = QVector3D(n023 + n012 + n310).normalized();
    QVector3D n1 = QVector3D(n132 + n012 + n310).normalized();
    QVector3D n2 = QVector3D(n132 + n012 + n023).normalized();
    QVector3D n3 = QVector3D(n132 + n310 + n023).normalized();

    // Colors
    QVector3D red(1.0f, 0.0f, 0.0f);
    QVector3D green(0.0f, 1.0f, 0.0f);
    QVector3D blue(0.0f, 0.0f, 1.0f);
    QVector3D white(1.0f, 1.0f, 1.0f);

    QVector<QVector3D> vertices = QVector<QVector3D>()
            << v0 << n0 << red
            << v1 << n1 << blue
            << v2 << n2 << green

            << v3 << n3 << white
            << v1 << n1 << blue
            << v0 << n0 << red

            << v0 << n0 << red
            << v2 << n2 << green
            << v3 << n3 << white

            << v1 << n1 << blue
            << v3 << n3 << white
            << v2 << n2 << green;


    float *rawVertexArray = reinterpret_cast<float *>(vertexBufferData.data());
    int idx = 0;

    Q_FOREACH (const QVector3D &v, vertices) {
        rawVertexArray[idx++] = v.x();
        rawVertexArray[idx++] = v.y();
        rawVertexArray[idx++] = v.z();
    }

    vertexDataBuffer->setData(vertexBufferData);

    // Attributes
    Qt3DRender::QAttribute *positionAttribute = new Qt3DRender::QAttribute();
    positionAttribute->setAttributeType(Qt3DRender::QAttribute::VertexAttribute);
    positionAttribute->setBuffer(vertexDataBuffer);
    positionAttribute->setDataType(Qt3DRender::QAttribute::Float);
    positionAttribute->setDataSize(3);
    positionAttribute->setByteOffset(0);
    positionAttribute->setByteStride(9 * sizeof(float));
    positionAttribute->setCount(12);
    positionAttribute->setName(Qt3DRender::QAttribute::defaultPositionAttributeName());

    Qt3DRender::QAttribute *normalAttribute = new Qt3DRender::QAttribute();
    normalAttribute->setAttributeType(Qt3DRender::QAttribute::VertexAttribute);
    normalAttribute->setBuffer(vertexDataBuffer);
    normalAttribute->setDataType(Qt3DRender::QAttribute::Float);
    normalAttribute->setDataSize(3);
    normalAttribute->setByteOffset(3 * sizeof(float));
    normalAttribute->setByteStride(9 * sizeof(float));
    normalAttribute->setCount(12);
    normalAttribute->setName(Qt3DRender::QAttribute::defaultNormalAttributeName());

    Qt3DRender::QAttribute *colorAttribute = new Qt3DRender::QAttribute();
    colorAttribute->setAttributeType(Qt3DRender::QAttribute::VertexAttribute);
    colorAttribute->setBuffer(vertexDataBuffer);
    colorAttribute->setDataType(Qt3DRender::QAttribute::Float);
    colorAttribute->setDataSize(3);
    colorAttribute->setByteOffset(6 * sizeof(float));
    colorAttribute->setByteStride(9 * sizeof(float));
    colorAttribute->setCount(12);
    colorAttribute->setName(Qt3DRender::QAttribute::defaultColorAttributeName());

    customGeometry->addAttribute(positionAttribute);
    customGeometry->addAttribute(normalAttribute);
    customGeometry->addAttribute(colorAttribute);

    customMeshRenderer->setInstanceCount(1);
    customMeshRenderer->setBaseVertex(0);
    customMeshRenderer->setBaseInstance(0);
    customMeshRenderer->setPrimitiveType(Qt3DRender::QGeometryRenderer::Triangles);
    customMeshRenderer->setGeometry(customGeometry);
    // 4 faces of 3 points
    customMeshRenderer->setPrimitiveCount(12);

    return customMeshRenderer;
}

class TestAspect : public Qt3DRender::QRenderAspect
{
public:
    TestAspect(Qt3DCore::QNode *root)
        : Qt3DRender::QRenderAspect()
    {
        Qt3DCore::QNodeVisitor visitor;
        visitor.traverse(root, this, &TestAspect::visitNode);
    }

    Qt3DRender::Render::NodeManagers *nodeManagers() const
    {
        return d_func()->m_renderer->nodeManagers();
    }

    void visitNode(Qt3DCore::QNode *node)
    {
        d_func()->createBackendNode(node);
    }
};

class tst_TrianglesExtractor : public QObject
{
    Q_OBJECT
private Q_SLOTS:

    void triangles_data()
    {
        QTest::addColumn<Qt3DRender::QGeometryRenderer *>("geomRenderer");
        QTest::addColumn<QVector<Qt3DRender::Render::TriangleBoundingVolume *> >("expectedVolumes");

        QVector<Qt3DRender::Render::TriangleBoundingVolume *> v =
                QVector<Qt3DRender::Render::TriangleBoundingVolume *>()
                << new Qt3DRender::Render::TriangleBoundingVolume(Qt3DCore::QNodeId(), QVector3D(0, 1, 0), QVector3D(1, 0, -1), QVector3D(-1, 0, -1))
                << new Qt3DRender::Render::TriangleBoundingVolume(Qt3DCore::QNodeId(), QVector3D(-1, 0, -1), QVector3D(1, 0, -1), QVector3D(0, 0, 1))
                << new Qt3DRender::Render::TriangleBoundingVolume(Qt3DCore::QNodeId(), QVector3D(0, 0, 1), QVector3D(0, 1, 0), QVector3D(-1, 0, -1))
                << new Qt3DRender::Render::TriangleBoundingVolume(Qt3DCore::QNodeId(), QVector3D(0, 1, 0), QVector3D(0, 0, 1), QVector3D(1, 0, -1));

        QTest::newRow("indexedMesh") << customIndexedGeometryRenderer() << v;
        QTest::newRow("nonIndexedMesh") << customNonIndexedGeometryRenderer() << v;
    }

    void triangles()
    {
        // GIVEN
        QFETCH(Qt3DRender::QGeometryRenderer *, geomRenderer);
        QFETCH(QVector<Qt3DRender::Render::TriangleBoundingVolume *>, expectedVolumes);
        TestAspect aspect(geomRenderer);
        Qt3DRender::Render::NodeManagers *manager = aspect.nodeManagers();

        // WHEN
        Qt3DRender::Render::GeometryRenderer *bGeomRenderer =
                manager->lookupResource
                <Qt3DRender::Render::GeometryRenderer,
                Qt3DRender::Render::GeometryRendererManager>
                (geomRenderer->id());
        // THEN
        QVERIFY(bGeomRenderer);

        // WHEN
        Qt3DRender::Render::TrianglesExtractor extractor(bGeomRenderer, manager);
        QVector<Qt3DRender::QBoundingVolume *> volumes = extractor.extract(Qt3DCore::QNodeId());

        // THEN
        QVERIFY(!volumes.empty());
        QCOMPARE(volumes.size(), expectedVolumes.size());
        for (int i = 0, m = volumes.size(); i < m; ++i) {
            const Qt3DRender::Render::TriangleBoundingVolume *expectedVolume = expectedVolumes.at(i);
            const Qt3DRender::Render::TriangleBoundingVolume *actualVolume = static_cast<Qt3DRender::Render::TriangleBoundingVolume *>(volumes.at(i));

            QCOMPARE(expectedVolume->id(), actualVolume->id());
            QCOMPARE(expectedVolume->a(), actualVolume->a());
            QCOMPARE(expectedVolume->b(), actualVolume->b());
            QCOMPARE(expectedVolume->c(), actualVolume->c());
        }
    }
};


QTEST_MAIN(tst_TrianglesExtractor)

#include "tst_trianglesextractor.moc"