// Copyright (C) 2017 Klaralvdalens Datakonsult AB (KDAB).
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0


#include <QtTest/QTest>

#include <QtCore/qmetaobject.h>
#include <Qt3DRender/private/qshadergenerator_p.h>
#include <Qt3DRender/private/qshaderlanguage_p.h>

using namespace Qt3DRender;
namespace
{
    QShaderFormat createFormat(QShaderFormat::Api api, int majorVersion, int minorVersion,
                               QShaderFormat::ShaderType shaderType= QShaderFormat::Fragment)
    {
        auto format = QShaderFormat();
        format.setApi(api);
        format.setVersion(QVersionNumber(majorVersion, minorVersion));
        format.setShaderType(shaderType);
        return format;
    }

    QShaderNodePort createPort(QShaderNodePort::Direction portDirection, const QString &portName)
    {
        auto port = QShaderNodePort();
        port.direction = portDirection;
        port.name = portName;
        return port;
    }

    QShaderNode createNode(const QList<QShaderNodePort> &ports, const QStringList &layers = QStringList())
    {
        auto node = QShaderNode();
        node.setUuid(QUuid::createUuid());
        node.setLayers(layers);
        for (const auto &port : ports)
            node.addPort(port);
        return node;
    }

    QShaderGraph::Edge createEdge(const QUuid &sourceUuid, const QString &sourceName,
                                  const QUuid &targetUuid, const QString &targetName,
                                  const QStringList &layers = QStringList())
    {
        auto edge = QShaderGraph::Edge();
        edge.sourceNodeUuid = sourceUuid;
        edge.sourcePortName = sourceName;
        edge.targetNodeUuid = targetUuid;
        edge.targetPortName = targetName;
        edge.layers = layers;
        return edge;
    }

    QShaderGraph createFragmentShaderGraph()
    {
        const auto openGLES2 = createFormat(QShaderFormat::OpenGLES, 2, 0);
        const auto openGL3 = createFormat(QShaderFormat::OpenGLCoreProfile, 3, 0);

        auto graph = QShaderGraph();

        auto worldPosition = createNode({
            createPort(QShaderNodePort::Output, "value")
        });
        worldPosition.setParameter("name", "worldPosition");
        worldPosition.addRule(openGLES2, QShaderNode::Rule("highp vec3 $value = $name;",
                                                           QByteArrayList() << "varying highp vec3 $name;"));
        worldPosition.addRule(openGL3, QShaderNode::Rule("vec3 $value = $name;",
                                                         QByteArrayList() << "in vec3 $name;"));

        auto texture = createNode({
            createPort(QShaderNodePort::Output, "texture")
        });
        texture.addRule(openGLES2, QShaderNode::Rule("sampler2D $texture = texture;",
                                                     QByteArrayList() << "uniform sampler2D texture;"));
        texture.addRule(openGL3, QShaderNode::Rule("sampler2D $texture = texture;",
                                                   QByteArrayList() << "uniform sampler2D texture;"));

        auto texCoord = createNode({
            createPort(QShaderNodePort::Output, "texCoord")
        });
        texCoord.addRule(openGLES2, QShaderNode::Rule("highp vec2 $texCoord = texCoord;",
                                                      QByteArrayList() << "varying highp vec2 texCoord;"));
        texCoord.addRule(openGL3, QShaderNode::Rule("vec2 $texCoord = texCoord;",
                                                    QByteArrayList() << "in vec2 texCoord;"));

        auto lightIntensity = createNode({
            createPort(QShaderNodePort::Output, "lightIntensity")
        });
        lightIntensity.addRule(openGLES2, QShaderNode::Rule("highp float $lightIntensity = lightIntensity;",
                                                            QByteArrayList() << "uniform highp float lightIntensity;"));
        lightIntensity.addRule(openGL3, QShaderNode::Rule("float $lightIntensity = lightIntensity;",
                                                          QByteArrayList() << "uniform float lightIntensity;"));

        auto exposure = createNode({
            createPort(QShaderNodePort::Output, "exposure")
        });
        exposure.addRule(openGLES2, QShaderNode::Rule("highp float $exposure = exposure;",
                                                      QByteArrayList() << "uniform highp float exposure;"));
        exposure.addRule(openGL3, QShaderNode::Rule("float $exposure = exposure;",
                                                    QByteArrayList() << "uniform float exposure;"));

        auto fragColor = createNode({
            createPort(QShaderNodePort::Input, "fragColor")
        });
        fragColor.addRule(openGLES2, QShaderNode::Rule("gl_fragColor = $fragColor;"));
        fragColor.addRule(openGL3, QShaderNode::Rule("fragColor = $fragColor;",
                                                     QByteArrayList() << "out vec4 fragColor;"));

        auto sampleTexture = createNode({
            createPort(QShaderNodePort::Input, "sampler"),
            createPort(QShaderNodePort::Input, "coord"),
            createPort(QShaderNodePort::Output, "color")
        });
        sampleTexture.addRule(openGLES2, QShaderNode::Rule("highp vec4 $color = texture2D($sampler, $coord);"));
        sampleTexture.addRule(openGL3, QShaderNode::Rule("vec4 $color = texture($sampler, $coord);"));

        auto lightFunction = createNode({
            createPort(QShaderNodePort::Input, "baseColor"),
            createPort(QShaderNodePort::Input, "position"),
            createPort(QShaderNodePort::Input, "lightIntensity"),
            createPort(QShaderNodePort::Output, "outputColor")
        });
        lightFunction.addRule(openGLES2, QShaderNode::Rule("highp vec4 $outputColor = lightModel($baseColor, $position, $lightIntensity);",
                                                           QByteArrayList() << "#pragma include es2/lightmodel.frag.inc"));
        lightFunction.addRule(openGL3, QShaderNode::Rule("vec4 $outputColor = lightModel($baseColor, $position, $lightIntensity);",
                                                         QByteArrayList() << "#pragma include gl3/lightmodel.frag.inc"));

        auto exposureFunction = createNode({
            createPort(QShaderNodePort::Input, "inputColor"),
            createPort(QShaderNodePort::Input, "exposure"),
            createPort(QShaderNodePort::Output, "outputColor")
        });
        exposureFunction.addRule(openGLES2, QShaderNode::Rule("highp vec4 $outputColor = $inputColor * pow(2.0, $exposure);"));
        exposureFunction.addRule(openGL3, QShaderNode::Rule("vec4 $outputColor = $inputColor * pow(2.0, $exposure);"));

        graph.addNode(worldPosition);
        graph.addNode(texture);
        graph.addNode(texCoord);
        graph.addNode(lightIntensity);
        graph.addNode(exposure);
        graph.addNode(fragColor);
        graph.addNode(sampleTexture);
        graph.addNode(lightFunction);
        graph.addNode(exposureFunction);

        graph.addEdge(createEdge(texture.uuid(), "texture", sampleTexture.uuid(), "sampler"));
        graph.addEdge(createEdge(texCoord.uuid(), "texCoord", sampleTexture.uuid(), "coord"));

        graph.addEdge(createEdge(worldPosition.uuid(), "value", lightFunction.uuid(), "position"));
        graph.addEdge(createEdge(sampleTexture.uuid(), "color", lightFunction.uuid(), "baseColor"));
        graph.addEdge(createEdge(lightIntensity.uuid(), "lightIntensity", lightFunction.uuid(), "lightIntensity"));

        graph.addEdge(createEdge(lightFunction.uuid(), "outputColor", exposureFunction.uuid(), "inputColor"));
        graph.addEdge(createEdge(exposure.uuid(), "exposure", exposureFunction.uuid(), "exposure"));

        graph.addEdge(createEdge(exposureFunction.uuid(), "outputColor", fragColor.uuid(), "fragColor"));

        return graph;
    }
}

class tst_QShaderGenerator : public QObject
{
    Q_OBJECT
private slots:
    void shouldHaveDefaultState();
    void shouldGenerateShaderCode_data();
    void shouldGenerateShaderCode();
    void shouldGenerateVersionCommands_data();
    void shouldGenerateVersionCommands();
    void shouldProcessLanguageQualifierAndTypeEnums_data();
    void shouldProcessLanguageQualifierAndTypeEnums();
    void shouldGenerateDifferentCodeDependingOnActiveLayers();
    void shouldUseGlobalVariableRatherThanTemporaries();
    void shouldGenerateTemporariesWisely();
    void shouldHandlePortNamesPrefixingOneAnother();
    void shouldHandleNodesWithMultipleOutputPorts();
    void shouldHandleExpressionsInInputNodes();
    void shouldGenerateLayerDefines();
};

void tst_QShaderGenerator::shouldHaveDefaultState()
{
    // GIVEN
    auto generator = QShaderGenerator();

    // THEN
    QVERIFY(generator.graph.nodes().isEmpty());
    QVERIFY(generator.graph.edges().isEmpty());
    QVERIFY(!generator.format.isValid());
}

void tst_QShaderGenerator::shouldGenerateShaderCode_data()
{
    QTest::addColumn<QShaderGraph>("graph");
    QTest::addColumn<QShaderFormat>("format");
    QTest::addColumn<QByteArray>("expectedCode");

    const auto graph = createFragmentShaderGraph();

    const auto openGLES2 = createFormat(QShaderFormat::OpenGLES, 2, 0);
    const auto openGL3 = createFormat(QShaderFormat::OpenGLCoreProfile, 3, 0);
    const auto openGL32 = createFormat(QShaderFormat::OpenGLCoreProfile, 3, 2);
    const auto openGL4 = createFormat(QShaderFormat::OpenGLCoreProfile, 4, 0);

    const auto versionGLES2 = QByteArrayList() << "#version 100" << "";
    const auto versionGL3 = QByteArrayList() << "#version 130" << "";
    const auto versionGL32 = QByteArrayList() << "#version 150 core" << "";
    const auto versionGL4 = QByteArrayList() << "#version 400 core" << "";

    const auto es2Code = QByteArrayList()
            << "varying highp vec2 texCoord;"
            << "uniform sampler2D texture;"
            << "uniform highp float lightIntensity;"
            << "varying highp vec3 worldPosition;"
            << "uniform highp float exposure;"
            << "#pragma include es2/lightmodel.frag.inc"
            << ""
            << "void main()"
            << "{"
            << "    gl_fragColor = (((((lightModel(((texture2D(texture, texCoord))), "
               "worldPosition, lightIntensity)))) * pow(2.0, exposure)));"
            << "}"
            << "";

    const auto gl3Code = QByteArrayList()
            << "in vec2 texCoord;"
            << "uniform sampler2D texture;"
            << "uniform float lightIntensity;"
            << "in vec3 worldPosition;"
            << "uniform float exposure;"
            << "#pragma include gl3/lightmodel.frag.inc"
            << "out vec4 fragColor;"
            << ""
            << "void main()"
            << "{"
            << "    fragColor = (((((lightModel(((texture(texture, texCoord))), worldPosition, "
               "lightIntensity)))) * pow(2.0, exposure)));"
            << "}"
            << "";

    QTest::newRow("EmptyGraphAndFormat") << QShaderGraph() << QShaderFormat() << QByteArrayLiteral("\n\n\nvoid main()\n{\n}\n");
    QTest::newRow("LightExposureGraphAndES2") << graph << openGLES2 << (versionGLES2 + es2Code).join('\n');
    QTest::newRow("LightExposureGraphAndGL3") << graph << openGL3 << (versionGL3 + gl3Code).join('\n');
    QTest::newRow("LightExposureGraphAndGL32") << graph << openGL32 << (versionGL32 + gl3Code).join('\n');
    QTest::newRow("LightExposureGraphAndGL4") << graph << openGL4 << (versionGL4 + gl3Code).join('\n');
}

void tst_QShaderGenerator::shouldGenerateShaderCode()
{
    // GIVEN
    QFETCH(QShaderGraph, graph);
    QFETCH(QShaderFormat, format);

    auto generator = QShaderGenerator();
    generator.graph = graph;
    generator.format = format;

    // WHEN
    const auto code = generator.createShaderCode();

    // THEN
    QFETCH(QByteArray, expectedCode);
    QCOMPARE(code, expectedCode);
}

void tst_QShaderGenerator::shouldGenerateVersionCommands_data()
{
    QTest::addColumn<QShaderFormat>("format");
    QTest::addColumn<QByteArray>("version");

    QTest::newRow("GLES2") << createFormat(QShaderFormat::OpenGLES, 2, 0) << QByteArrayLiteral("#version 100");
    QTest::newRow("GLES3") << createFormat(QShaderFormat::OpenGLES, 3, 0) << QByteArrayLiteral("#version 300 es");

    QTest::newRow("GL20") << createFormat(QShaderFormat::OpenGLNoProfile, 2, 0) << QByteArrayLiteral("#version 110");
    QTest::newRow("GL21") << createFormat(QShaderFormat::OpenGLNoProfile, 2, 1) << QByteArrayLiteral("#version 120");
    QTest::newRow("GL30") << createFormat(QShaderFormat::OpenGLNoProfile, 3, 0) << QByteArrayLiteral("#version 130");
    QTest::newRow("GL31") << createFormat(QShaderFormat::OpenGLNoProfile, 3, 1) << QByteArrayLiteral("#version 140");
    QTest::newRow("GL32") << createFormat(QShaderFormat::OpenGLNoProfile, 3, 2) << QByteArrayLiteral("#version 150");
    QTest::newRow("GL33") << createFormat(QShaderFormat::OpenGLNoProfile, 3, 3) << QByteArrayLiteral("#version 330");
    QTest::newRow("GL40") << createFormat(QShaderFormat::OpenGLNoProfile, 4, 0) << QByteArrayLiteral("#version 400");
    QTest::newRow("GL41") << createFormat(QShaderFormat::OpenGLNoProfile, 4, 1) << QByteArrayLiteral("#version 410");
    QTest::newRow("GL42") << createFormat(QShaderFormat::OpenGLNoProfile, 4, 2) << QByteArrayLiteral("#version 420");
    QTest::newRow("GL43") << createFormat(QShaderFormat::OpenGLNoProfile, 4, 3) << QByteArrayLiteral("#version 430");

    QTest::newRow("GL20core") << createFormat(QShaderFormat::OpenGLCoreProfile, 2, 0) << QByteArrayLiteral("#version 110");
    QTest::newRow("GL21core") << createFormat(QShaderFormat::OpenGLCoreProfile, 2, 1) << QByteArrayLiteral("#version 120");
    QTest::newRow("GL30core") << createFormat(QShaderFormat::OpenGLCoreProfile, 3, 0) << QByteArrayLiteral("#version 130");
    QTest::newRow("GL31core") << createFormat(QShaderFormat::OpenGLCoreProfile, 3, 1) << QByteArrayLiteral("#version 140");
    QTest::newRow("GL32core") << createFormat(QShaderFormat::OpenGLCoreProfile, 3, 2) << QByteArrayLiteral("#version 150 core");
    QTest::newRow("GL33core") << createFormat(QShaderFormat::OpenGLCoreProfile, 3, 3) << QByteArrayLiteral("#version 330 core");
    QTest::newRow("GL40core") << createFormat(QShaderFormat::OpenGLCoreProfile, 4, 0) << QByteArrayLiteral("#version 400 core");
    QTest::newRow("GL41core") << createFormat(QShaderFormat::OpenGLCoreProfile, 4, 1) << QByteArrayLiteral("#version 410 core");
    QTest::newRow("GL42core") << createFormat(QShaderFormat::OpenGLCoreProfile, 4, 2) << QByteArrayLiteral("#version 420 core");
    QTest::newRow("GL43core") << createFormat(QShaderFormat::OpenGLCoreProfile, 4, 3) << QByteArrayLiteral("#version 430 core");

    QTest::newRow("GL20compatibility") << createFormat(QShaderFormat::OpenGLCompatibilityProfile, 2, 0) << QByteArrayLiteral("#version 110");
    QTest::newRow("GL21compatibility") << createFormat(QShaderFormat::OpenGLCompatibilityProfile, 2, 1) << QByteArrayLiteral("#version 120");
    QTest::newRow("GL30compatibility") << createFormat(QShaderFormat::OpenGLCompatibilityProfile, 3, 0) << QByteArrayLiteral("#version 130");
    QTest::newRow("GL31compatibility") << createFormat(QShaderFormat::OpenGLCompatibilityProfile, 3, 1) << QByteArrayLiteral("#version 140");
    QTest::newRow("GL32compatibility") << createFormat(QShaderFormat::OpenGLCompatibilityProfile, 3, 2) << QByteArrayLiteral("#version 150 compatibility");
    QTest::newRow("GL33compatibility") << createFormat(QShaderFormat::OpenGLCompatibilityProfile, 3, 3) << QByteArrayLiteral("#version 330 compatibility");
    QTest::newRow("GL40compatibility") << createFormat(QShaderFormat::OpenGLCompatibilityProfile, 4, 0) << QByteArrayLiteral("#version 400 compatibility");
    QTest::newRow("GL41compatibility") << createFormat(QShaderFormat::OpenGLCompatibilityProfile, 4, 1) << QByteArrayLiteral("#version 410 compatibility");
    QTest::newRow("GL42compatibility") << createFormat(QShaderFormat::OpenGLCompatibilityProfile, 4, 2) << QByteArrayLiteral("#version 420 compatibility");
    QTest::newRow("GL43compatibility") << createFormat(QShaderFormat::OpenGLCompatibilityProfile, 4, 3) << QByteArrayLiteral("#version 430 compatibility");
}

void tst_QShaderGenerator::shouldGenerateVersionCommands()
{
    // GIVEN
    QFETCH(QShaderFormat, format);

    auto generator = QShaderGenerator();
    generator.format = format;

    // WHEN
    const auto code = generator.createShaderCode();

    // THEN
    QFETCH(QByteArray, version);
    const auto expectedCode = (QByteArrayList() << version
                                                << ""
                                                << ""
                                                << "void main()"
                                                << "{"
                                                << "}"
                                                << "").join('\n');
    QCOMPARE(code, expectedCode);
}


namespace {
    QString toGlsl(QShaderLanguage::StorageQualifier qualifier, const QShaderFormat &format)
    {
        if (format.version().majorVersion() <= 2) {
            // Note we're assuming fragment shader only here, it'd be different
            // values for vertex shader, will need to be fixed properly at some
            // point but isn't necessary yet (this problem already exists in past
            // commits anyway)
            switch (qualifier) {
            case QShaderLanguage::Const:
                return "const";
            case QShaderLanguage::Input:
                return "varying";
            case QShaderLanguage::BuiltIn:
                return "//";
            case QShaderLanguage::Output:
                return ""; // Although fragment shaders for <=2 only have fixed outputs
            case QShaderLanguage::Uniform:
                return "uniform";
            }
        } else {
            switch (qualifier) {
            case QShaderLanguage::Const:
                return "const";
            case QShaderLanguage::Input:
                return "in";
            case QShaderLanguage::BuiltIn:
                return "//";
            case QShaderLanguage::Output:
                return "out";
            case QShaderLanguage::Uniform:
                return "uniform";
            }
        }

        Q_UNREACHABLE();
    }

    QString toGlsl(QShaderLanguage::VariableType type)
    {
        switch (type) {
        case QShaderLanguage::Bool:
            return "bool";
        case QShaderLanguage::Int:
            return "int";
        case QShaderLanguage::Uint:
            return "uint";
        case QShaderLanguage::Float:
            return "float";
        case QShaderLanguage::Double:
            return "double";
        case QShaderLanguage::Vec2:
            return "vec2";
        case QShaderLanguage::Vec3:
            return "vec3";
        case QShaderLanguage::Vec4:
            return "vec4";
        case QShaderLanguage::DVec2:
            return "dvec2";
        case QShaderLanguage::DVec3:
            return "dvec3";
        case QShaderLanguage::DVec4:
            return "dvec4";
        case QShaderLanguage::BVec2:
            return "bvec2";
        case QShaderLanguage::BVec3:
            return "bvec3";
        case QShaderLanguage::BVec4:
            return "bvec4";
        case QShaderLanguage::IVec2:
            return "ivec2";
        case QShaderLanguage::IVec3:
            return "ivec3";
        case QShaderLanguage::IVec4:
            return "ivec4";
        case QShaderLanguage::UVec2:
            return "uvec2";
        case QShaderLanguage::UVec3:
            return "uvec3";
        case QShaderLanguage::UVec4:
            return "uvec4";
        case QShaderLanguage::Mat2:
            return "mat2";
        case QShaderLanguage::Mat3:
            return "mat3";
        case QShaderLanguage::Mat4:
            return "mat4";
        case QShaderLanguage::Mat2x2:
            return "mat2x2";
        case QShaderLanguage::Mat2x3:
            return "mat2x3";
        case QShaderLanguage::Mat2x4:
            return "mat2x4";
        case QShaderLanguage::Mat3x2:
            return "mat3x2";
        case QShaderLanguage::Mat3x3:
            return "mat3x3";
        case QShaderLanguage::Mat3x4:
            return "mat3x4";
        case QShaderLanguage::Mat4x2:
            return "mat4x2";
        case QShaderLanguage::Mat4x3:
            return "mat4x3";
        case QShaderLanguage::Mat4x4:
            return "mat4x4";
        case QShaderLanguage::DMat2:
            return "dmat2";
        case QShaderLanguage::DMat3:
            return "dmat3";
        case QShaderLanguage::DMat4:
            return "dmat4";
        case QShaderLanguage::DMat2x2:
            return "dmat2x2";
        case QShaderLanguage::DMat2x3:
            return "dmat2x3";
        case QShaderLanguage::DMat2x4:
            return "dmat2x4";
        case QShaderLanguage::DMat3x2:
            return "dmat3x2";
        case QShaderLanguage::DMat3x3:
            return "dmat3x3";
        case QShaderLanguage::DMat3x4:
            return "dmat3x4";
        case QShaderLanguage::DMat4x2:
            return "dmat4x2";
        case QShaderLanguage::DMat4x3:
            return "dmat4x3";
        case QShaderLanguage::DMat4x4:
            return "dmat4x4";
        case QShaderLanguage::Sampler1D:
            return "sampler1D";
        case QShaderLanguage::Sampler2D:
            return "sampler2D";
        case QShaderLanguage::Sampler3D:
            return "sampler3D";
        case QShaderLanguage::SamplerCube:
            return "samplerCube";
        case QShaderLanguage::Sampler2DRect:
            return "sampler2DRect";
        case QShaderLanguage::Sampler2DMs:
            return "sampler2DMS";
        case QShaderLanguage::SamplerBuffer:
            return "samplerBuffer";
        case QShaderLanguage::Sampler1DArray:
            return "sampler1DArray";
        case QShaderLanguage::Sampler2DArray:
            return "sampler2DArray";
        case QShaderLanguage::Sampler2DMsArray:
            return "sampler2DMSArray";
        case QShaderLanguage::SamplerCubeArray:
            return "samplerCubeArray";
        case QShaderLanguage::Sampler1DShadow:
            return "sampler1DShadow";
        case QShaderLanguage::Sampler2DShadow:
            return "sampler2DShadow";
        case QShaderLanguage::Sampler2DRectShadow:
            return "sampler2DRectShadow";
        case QShaderLanguage::Sampler1DArrayShadow:
            return "sampler1DArrayShadow";
        case QShaderLanguage::Sampler2DArrayShadow:
            return "sampler2DArrayShadow";
        case QShaderLanguage::SamplerCubeShadow:
            return "samplerCubeShadow";
        case QShaderLanguage::SamplerCubeArrayShadow:
            return "samplerCubeArrayShadow";
        case QShaderLanguage::ISampler1D:
            return "isampler1D";
        case QShaderLanguage::ISampler2D:
            return "isampler2D";
        case QShaderLanguage::ISampler3D:
            return "isampler3D";
        case QShaderLanguage::ISamplerCube:
            return "isamplerCube";
        case QShaderLanguage::ISampler2DRect:
            return "isampler2DRect";
        case QShaderLanguage::ISampler2DMs:
            return "isampler2DMS";
        case QShaderLanguage::ISamplerBuffer:
            return "isamplerBuffer";
        case QShaderLanguage::ISampler1DArray:
            return "isampler1DArray";
        case QShaderLanguage::ISampler2DArray:
            return "isampler2DArray";
        case QShaderLanguage::ISampler2DMsArray:
            return "isampler2DMSArray";
        case QShaderLanguage::ISamplerCubeArray:
            return "isamplerCubeArray";
        case QShaderLanguage::USampler1D:
            return "usampler1D";
        case QShaderLanguage::USampler2D:
            return "usampler2D";
        case QShaderLanguage::USampler3D:
            return "usampler3D";
        case QShaderLanguage::USamplerCube:
            return "usamplerCube";
        case QShaderLanguage::USampler2DRect:
            return "usampler2DRect";
        case QShaderLanguage::USampler2DMs:
            return "usampler2DMS";
        case QShaderLanguage::USamplerBuffer:
            return "usamplerBuffer";
        case QShaderLanguage::USampler1DArray:
            return "usampler1DArray";
        case QShaderLanguage::USampler2DArray:
            return "usampler2DArray";
        case QShaderLanguage::USampler2DMsArray:
            return "usampler2DMSArray";
        case QShaderLanguage::USamplerCubeArray:
            return "usamplerCubeArray";
        }

        Q_UNREACHABLE();
    }
}

void tst_QShaderGenerator::shouldProcessLanguageQualifierAndTypeEnums_data()
{
    QTest::addColumn<QShaderGraph>("graph");
    QTest::addColumn<QShaderFormat>("format");
    QTest::addColumn<QByteArray>("expectedCode");

    {
        const auto es2 = createFormat(QShaderFormat::OpenGLES, 2, 0);
        const auto es3 = createFormat(QShaderFormat::OpenGLES, 3, 0);
        const auto gl2 = createFormat(QShaderFormat::OpenGLNoProfile, 2, 0);
        const auto gl3 = createFormat(QShaderFormat::OpenGLCoreProfile, 3, 0);
        const auto gl4 = createFormat(QShaderFormat::OpenGLCoreProfile, 4, 0);

        const auto qualifierEnum = QMetaEnum::fromType<QShaderLanguage::StorageQualifier>();
        const auto typeEnum = QMetaEnum::fromType<QShaderLanguage::VariableType>();

        for (int qualifierIndex = 0; qualifierIndex < qualifierEnum.keyCount(); qualifierIndex++) {
            const auto qualifierName = qualifierEnum.key(qualifierIndex);
            const auto qualifierValue = static_cast<QShaderLanguage::StorageQualifier>(qualifierEnum.value(qualifierIndex));

            for (int typeIndex = 0; typeIndex < typeEnum.keyCount(); typeIndex++) {
                const auto typeName = typeEnum.key(typeIndex);
                const auto typeValue = static_cast<QShaderLanguage::VariableType>(typeEnum.value(typeIndex));

                auto graph = QShaderGraph();

                auto worldPosition = createNode({
                    createPort(QShaderNodePort::Output, "value")
                });
                worldPosition.setParameter("name", "worldPosition");
                worldPosition.setParameter("qualifier", QVariant::fromValue<QShaderLanguage::StorageQualifier>(qualifierValue));
                worldPosition.setParameter("type", QVariant::fromValue<QShaderLanguage::VariableType>(typeValue));
                worldPosition.addRule(es2, QShaderNode::Rule("highp $type $value = $name;",
                                                             QByteArrayList() << "$qualifier highp $type $name;"));
                worldPosition.addRule(gl2, QShaderNode::Rule("$type $value = $name;",
                                                             QByteArrayList() << "$qualifier $type $name;"));
                worldPosition.addRule(gl3, QShaderNode::Rule("$type $value = $name;",
                                                             QByteArrayList() << "$qualifier $type $name;"));

                auto fragColor = createNode({
                    createPort(QShaderNodePort::Input, "fragColor")
                });
                fragColor.addRule(es2, QShaderNode::Rule("gl_fragColor = $fragColor;"));
                fragColor.addRule(gl2, QShaderNode::Rule("gl_fragColor = $fragColor;"));
                fragColor.addRule(gl3, QShaderNode::Rule("fragColor = $fragColor;",
                                                         QByteArrayList() << "out vec4 fragColor;"));

                graph.addNode(worldPosition);
                graph.addNode(fragColor);

                graph.addEdge(createEdge(worldPosition.uuid(), "value", fragColor.uuid(), "fragColor"));

                const auto gl2Code = (QByteArrayList() << "#version 110"
                                                       << ""
                                                       << QStringLiteral("%1 %2 worldPosition;").arg(toGlsl(qualifierValue, gl2))
                                                                                                .arg(toGlsl(typeValue))
                                                                                                .toUtf8()
                                                       << ""
                                                       << "void main()"
                                                       << "{"
                                                       << "    gl_fragColor = worldPosition;"
                                                       << "}"
                                                       << "").join("\n");
                const auto gl3Code = (QByteArrayList() << "#version 130"
                                                       << ""
                                                       << QStringLiteral("%1 %2 worldPosition;").arg(toGlsl(qualifierValue, gl3))
                                                                                                .arg(toGlsl(typeValue))
                                                                                                .toUtf8()
                                                       << "out vec4 fragColor;"
                                                       << ""
                                                       << "void main()"
                                                       << "{"
                                                       << "    fragColor = worldPosition;"
                                                       << "}"
                                                       << "").join("\n");
                const auto gl4Code = (QByteArrayList() << "#version 400 core"
                                                       << ""
                                                       << QStringLiteral("%1 %2 worldPosition;").arg(toGlsl(qualifierValue, gl4))
                                                                                                .arg(toGlsl(typeValue))
                                                                                                .toUtf8()
                                                       << "out vec4 fragColor;"
                                                       << ""
                                                       << "void main()"
                                                       << "{"
                                                       << "    fragColor = worldPosition;"
                                                       << "}"
                                                       << "").join("\n");
                const auto es2Code = (QByteArrayList() << "#version 100"
                                                       << ""
                                                       << QStringLiteral("%1 highp %2 worldPosition;").arg(toGlsl(qualifierValue, es2))
                                                                                                      .arg(toGlsl(typeValue))
                                                                                                      .toUtf8()
                                                       << ""
                                                       << "void main()"
                                                       << "{"
                                                       << "    gl_fragColor = worldPosition;"
                                                       << "}"
                                                       << "").join("\n");
                const auto es3Code = (QByteArrayList() << "#version 300 es"
                                                       << ""
                                                       << QStringLiteral("%1 highp %2 worldPosition;").arg(toGlsl(qualifierValue, es3))
                                                                                                      .arg(toGlsl(typeValue))
                                                                                                      .toUtf8()
                                                       << ""
                                                       << "void main()"
                                                       << "{"
                                                       << "    gl_fragColor = worldPosition;"
                                                       << "}"
                                                       << "").join("\n");

                QTest::addRow("%s %s ES2", qualifierName, typeName) << graph << es2 << es2Code;
                QTest::addRow("%s %s ES3", qualifierName, typeName) << graph << es3 << es3Code;
                QTest::addRow("%s %s GL2", qualifierName, typeName) << graph << gl2 << gl2Code;
                QTest::addRow("%s %s GL3", qualifierName, typeName) << graph << gl3 << gl3Code;
                QTest::addRow("%s %s GL4", qualifierName, typeName) << graph << gl4 << gl4Code;
            }
        }
    }

    {
            const auto es2 = createFormat(QShaderFormat::OpenGLES, 2, 0, QShaderFormat::Vertex);
            const auto es3 = createFormat(QShaderFormat::OpenGLES, 3, 0, QShaderFormat::Vertex);
            const auto gl2 = createFormat(QShaderFormat::OpenGLNoProfile, 2, 0, QShaderFormat::Vertex);
            const auto gl3 = createFormat(QShaderFormat::OpenGLCoreProfile, 3, 0, QShaderFormat::Vertex);
            const auto gl4 = createFormat(QShaderFormat::OpenGLCoreProfile, 4, 0, QShaderFormat::Vertex);

            auto graph = QShaderGraph();

            auto vertexPosition = createNode({
                createPort(QShaderNodePort::Output, "value")
            });
            vertexPosition.setParameter("name", "vertexPosition");
            vertexPosition.setParameter("qualifier", QVariant::fromValue<QShaderLanguage::StorageQualifier>(QShaderLanguage::Input));
            vertexPosition.setParameter("type", QVariant::fromValue<QShaderLanguage::VariableType>(QShaderLanguage::Vec4));

            vertexPosition.addRule(es2, QShaderNode::Rule("",
                                                         QByteArrayList() << "$qualifier highp $type $name;"));
            vertexPosition.addRule(gl2, QShaderNode::Rule("",
                                                         QByteArrayList() << "$qualifier $type $name;"));
            vertexPosition.addRule(gl3, QShaderNode::Rule("",
                                                         QByteArrayList() << "$qualifier $type $name;"));

            graph.addNode(vertexPosition);

            const auto gl2Code = (QByteArrayList() << "#version 110"
                                                   << ""
                                                   << ""
                                                   << "void main()"
                                                   << "{"
                                                   << "}"
                                                   << "").join("\n");
            const auto gl3Code = (QByteArrayList() << "#version 130"
                                                   << ""
                                                   << ""
                                                   << "void main()"
                                                   << "{"
                                                   << "}"
                                                   << "").join("\n");
            const auto gl4Code = (QByteArrayList() << "#version 400 core"
                                                   << ""
                                                   << ""
                                                   << "void main()"
                                                   << "{"
                                                   << "}"
                                                   << "").join("\n");
            const auto es2Code = (QByteArrayList() << "#version 100"
                                                   << ""
                                                   << ""
                                                   << "void main()"
                                                   << "{"
                                                   << "}"
                                                   << "").join("\n");
            const auto es3Code = (QByteArrayList() << "#version 300 es"
                                                   << ""
                                                   << ""
                                                   << "void main()"
                                                   << "{"
                                                   << "}"
                                                   << "").join("\n");

            QTest::addRow("Attribute header substitution ES2") << graph << es2 << es2Code;
            QTest::addRow("Attribute header substitution ES3") << graph << es3 << es3Code;
            QTest::addRow("Attribute header substitution GL2") << graph << gl2 << gl2Code;
            QTest::addRow("Attribute header substitution GL3") << graph << gl3 << gl3Code;
            QTest::addRow("Attribute header substitution GL4") << graph << gl4 << gl4Code;
    }
}

void tst_QShaderGenerator::shouldProcessLanguageQualifierAndTypeEnums()
{
    // GIVEN
    QFETCH(QShaderGraph, graph);
    QFETCH(QShaderFormat, format);

    auto generator = QShaderGenerator();
    generator.graph = graph;
    generator.format = format;

    // WHEN
    const auto code = generator.createShaderCode();

    // THEN
    QFETCH(QByteArray, expectedCode);
    QCOMPARE(code, expectedCode);
}

void tst_QShaderGenerator::shouldGenerateDifferentCodeDependingOnActiveLayers()
{
    // GIVEN
    const auto gl4 = createFormat(QShaderFormat::OpenGLCoreProfile, 4, 0);

    auto texCoord = createNode({
        createPort(QShaderNodePort::Output, "texCoord")
    }, {
        "diffuseTexture",
        "normalTexture"
    });
    texCoord.addRule(gl4, QShaderNode::Rule("vec2 $texCoord = texCoord;",
                                            QByteArrayList() << "in vec2 texCoord;"));
    auto diffuseUniform = createNode({
        createPort(QShaderNodePort::Output, "color")
    }, {"diffuseUniform"});
    diffuseUniform.addRule(gl4, QShaderNode::Rule("vec4 $color = diffuseUniform;",
                                                  QByteArrayList() << "uniform vec4 diffuseUniform;"));
    auto diffuseTexture = createNode({
        createPort(QShaderNodePort::Input, "coord"),
        createPort(QShaderNodePort::Output, "color")
    }, {"diffuseTexture"});
    diffuseTexture.addRule(gl4, QShaderNode::Rule("vec4 $color = texture2D(diffuseTexture, $coord);",
                                                 QByteArrayList() << "uniform sampler2D diffuseTexture;"));
    auto normalUniform = createNode({
        createPort(QShaderNodePort::Output, "normal")
    }, {"normalUniform"});
    normalUniform.addRule(gl4, QShaderNode::Rule("vec3 $normal = normalUniform;",
                                                 QByteArrayList() << "uniform vec3 normalUniform;"));
    auto normalTexture = createNode({
        createPort(QShaderNodePort::Input, "coord"),
        createPort(QShaderNodePort::Output, "normal")
    }, {"normalTexture"});
    normalTexture.addRule(gl4, QShaderNode::Rule("vec3 $normal = texture2D(normalTexture, $coord).rgb;",
                                                 QByteArrayList() << "uniform sampler2D normalTexture;"));
    auto lightFunction = createNode({
        createPort(QShaderNodePort::Input, "color"),
        createPort(QShaderNodePort::Input, "normal"),
        createPort(QShaderNodePort::Output, "output")
    });
    lightFunction.addRule(gl4, QShaderNode::Rule("vec4 $output = lightModel($color, $normal);",
                                                 QByteArrayList() << "#pragma include gl4/lightmodel.frag.inc"));
    auto fragColor = createNode({
        createPort(QShaderNodePort::Input, "fragColor")
    });
    fragColor.addRule(gl4, QShaderNode::Rule("fragColor = $fragColor;",
                                             QByteArrayList() << "out vec4 fragColor;"));

    const auto graph = [=] {
        auto res = QShaderGraph();

        res.addNode(texCoord);
        res.addNode(diffuseUniform);
        res.addNode(diffuseTexture);
        res.addNode(normalUniform);
        res.addNode(normalTexture);
        res.addNode(lightFunction);
        res.addNode(fragColor);

        res.addEdge(createEdge(diffuseUniform.uuid(), "color", lightFunction.uuid(), "color", {"diffuseUniform"}));
        res.addEdge(createEdge(texCoord.uuid(), "texCoord", diffuseTexture.uuid(), "coord", {"diffuseTexture"}));
        res.addEdge(createEdge(diffuseTexture.uuid(), "color", lightFunction.uuid(), "color", {"diffuseTexture"}));

        res.addEdge(createEdge(normalUniform.uuid(), "normal", lightFunction.uuid(), "normal", {"normalUniform"}));
        res.addEdge(createEdge(texCoord.uuid(), "texCoord", normalTexture.uuid(), "coord", {"normalTexture"}));
        res.addEdge(createEdge(normalTexture.uuid(), "normal", lightFunction.uuid(), "normal", {"normalTexture"}));

        res.addEdge(createEdge(lightFunction.uuid(), "output", fragColor.uuid(), "fragColor"));

        return res;
    }();

    auto generator = QShaderGenerator();
    generator.graph = graph;
    generator.format = gl4;

    {
        // WHEN
        const auto code = generator.createShaderCode({"diffuseUniform", "normalUniform"});

        // THEN
        const auto expected = QByteArrayList()
                << "#version 400 core"
                << ""
                << "#define LAYER_diffuseUniform"
                << "#define LAYER_normalUniform"
                << "uniform vec3 normalUniform;"
                << "uniform vec4 diffuseUniform;"
                << "#pragma include gl4/lightmodel.frag.inc"
                << "out vec4 fragColor;"
                << ""
                << "void main()"
                << "{"
                << "    fragColor = ((lightModel(diffuseUniform, normalUniform)));"
                << "}"
                << "";
        QCOMPARE(code, expected.join("\n"));
    }

    {
        // WHEN
        const auto code = generator.createShaderCode({"diffuseUniform", "normalTexture"});

        // THEN
        const auto expected = QByteArrayList() << "#version 400 core"
                                               << ""
                                               << "#define LAYER_diffuseUniform"
                                               << "#define LAYER_normalTexture"
                                               << "in vec2 texCoord;"
                                               << "uniform sampler2D normalTexture;"
                                               << "uniform vec4 diffuseUniform;"
                                               << "#pragma include gl4/lightmodel.frag.inc"
                                               << "out vec4 fragColor;"
                                               << ""
                                               << "void main()"
                                               << "{"
                                               << "    fragColor = ((lightModel(diffuseUniform, "
                                                  "texture2D(normalTexture, texCoord).rgb)));"
                                               << "}"
                                               << "";
        QCOMPARE(code, expected.join("\n"));
    }

    {
        // WHEN
        const auto code = generator.createShaderCode({"diffuseTexture", "normalUniform"});

        // THEN
        const auto expected = QByteArrayList()
                << "#version 400 core"
                << ""
                << "#define LAYER_diffuseTexture"
                << "#define LAYER_normalUniform"
                << "in vec2 texCoord;"
                << "uniform vec3 normalUniform;"
                << "uniform sampler2D diffuseTexture;"
                << "#pragma include gl4/lightmodel.frag.inc"
                << "out vec4 fragColor;"
                << ""
                << "void main()"
                << "{"
                << "    fragColor = ((lightModel(texture2D(diffuseTexture, texCoord), "
                   "normalUniform)));"
                << "}"
                << "";
        QCOMPARE(code, expected.join("\n"));
    }

    {
        // WHEN
        const auto code = generator.createShaderCode({"diffuseTexture", "normalTexture"});

        // THEN
        const auto expected = QByteArrayList()
                << "#version 400 core"
                << ""
                << "#define LAYER_diffuseTexture"
                << "#define LAYER_normalTexture"
                << "in vec2 texCoord;"
                << "uniform sampler2D normalTexture;"
                << "uniform sampler2D diffuseTexture;"
                << "#pragma include gl4/lightmodel.frag.inc"
                << "out vec4 fragColor;"
                << ""
                << "void main()"
                << "{"
                << "    fragColor = ((lightModel(texture2D(diffuseTexture, texCoord), "
                   "texture2D(normalTexture, texCoord).rgb)));"
                << "}"
                << "";
        QCOMPARE(code, expected.join("\n"));
    }
}

void tst_QShaderGenerator::shouldUseGlobalVariableRatherThanTemporaries()
{
    // GIVEN
    const auto gl4 = createFormat(QShaderFormat::OpenGLCoreProfile, 4, 0);

    {
        // WHEN
        auto vertexPosition = createNode({
                                             createPort(QShaderNodePort::Output, "vertexPosition")
                                         });
        vertexPosition.addRule(gl4, QShaderNode::Rule("vec4 $vertexPosition = vertexPosition;",
                                                      QByteArrayList() << "in vec4 vertexPosition;"));

        auto fakeMultiPlyNoSpace = createNode({
                                                  createPort(QShaderNodePort::Input, "varName"),
                                                  createPort(QShaderNodePort::Output, "out")
                                              });
        fakeMultiPlyNoSpace.addRule(gl4, QShaderNode::Rule("vec4 $out = $varName*speed;"));

        auto fakeMultiPlySpace = createNode({
                                                  createPort(QShaderNodePort::Input, "varName"),
                                                  createPort(QShaderNodePort::Output, "out")
                                              });
        fakeMultiPlySpace.addRule(gl4, QShaderNode::Rule("vec4 $out = $varName * speed;"));

        auto fakeJoinNoSpace = createNode({
                                                  createPort(QShaderNodePort::Input, "varName"),
                                                  createPort(QShaderNodePort::Output, "out")
                                          });
        fakeJoinNoSpace.addRule(gl4, QShaderNode::Rule("vec4 $out = vec4($varName.xyz,$varName.w);"));

        auto fakeJoinSpace = createNode({
                                              createPort(QShaderNodePort::Input, "varName"),
                                              createPort(QShaderNodePort::Output, "out")
                                          });
        fakeJoinSpace.addRule(gl4, QShaderNode::Rule("vec4 $out = vec4($varName.xyz, $varName.w);"));

        auto fakeAdd = createNode({
                                            createPort(QShaderNodePort::Input, "varName"),
                                            createPort(QShaderNodePort::Output, "out")
                                        });
        fakeAdd.addRule(gl4, QShaderNode::Rule("vec4 $out = $varName.xyzw + $varName;"));

        auto fakeSub = createNode({
                                            createPort(QShaderNodePort::Input, "varName"),
                                            createPort(QShaderNodePort::Output, "out")
                                        });
        fakeSub.addRule(gl4, QShaderNode::Rule("vec4 $out = $varName.xyzw - $varName;"));

        auto fakeDiv = createNode({
                                            createPort(QShaderNodePort::Input, "varName"),
                                            createPort(QShaderNodePort::Output, "out")
                                        });
        fakeDiv.addRule(gl4, QShaderNode::Rule("vec4 $out = $varName / v0;"));

        auto fragColor = createNode({
            createPort(QShaderNodePort::Input, "input1"),
            createPort(QShaderNodePort::Input, "input2"),
            createPort(QShaderNodePort::Input, "input3"),
            createPort(QShaderNodePort::Input, "input4"),
            createPort(QShaderNodePort::Input, "input5"),
            createPort(QShaderNodePort::Input, "input6"),
            createPort(QShaderNodePort::Input, "input7")
        });
        fragColor.addRule(gl4, QShaderNode::Rule("fragColor = $input1 + $input2 + $input3 + $input4 + $input5 + $input6 + $input7;",
                                                 QByteArrayList() << "out vec4 fragColor;"));

        const auto graph = [=] {
            auto res = QShaderGraph();

            res.addNode(vertexPosition);
            res.addNode(fakeMultiPlyNoSpace);
            res.addNode(fakeMultiPlySpace);
            res.addNode(fakeJoinNoSpace);
            res.addNode(fakeJoinSpace);
            res.addNode(fakeAdd);
            res.addNode(fakeSub);
            res.addNode(fakeDiv);
            res.addNode(fragColor);

            res.addEdge(createEdge(vertexPosition.uuid(), "vertexPosition", fakeMultiPlyNoSpace.uuid(), "varName"));
            res.addEdge(createEdge(vertexPosition.uuid(), "vertexPosition", fakeMultiPlySpace.uuid(), "varName"));
            res.addEdge(createEdge(vertexPosition.uuid(), "vertexPosition", fakeJoinNoSpace.uuid(), "varName"));
            res.addEdge(createEdge(vertexPosition.uuid(), "vertexPosition", fakeJoinSpace.uuid(), "varName"));
            res.addEdge(createEdge(vertexPosition.uuid(), "vertexPosition", fakeAdd.uuid(), "varName"));
            res.addEdge(createEdge(vertexPosition.uuid(), "vertexPosition", fakeSub.uuid(), "varName"));
            res.addEdge(createEdge(vertexPosition.uuid(), "vertexPosition", fakeDiv.uuid(), "varName"));
            res.addEdge(createEdge(fakeMultiPlyNoSpace.uuid(), "out", fragColor.uuid(), "input1"));
            res.addEdge(createEdge(fakeMultiPlySpace.uuid(), "out", fragColor.uuid(), "input2"));
            res.addEdge(createEdge(fakeJoinNoSpace.uuid(), "out", fragColor.uuid(), "input3"));
            res.addEdge(createEdge(fakeJoinSpace.uuid(), "out", fragColor.uuid(), "input4"));
            res.addEdge(createEdge(fakeAdd.uuid(), "out", fragColor.uuid(), "input5"));
            res.addEdge(createEdge(fakeSub.uuid(), "out", fragColor.uuid(), "input6"));
            res.addEdge(createEdge(fakeDiv.uuid(), "out", fragColor.uuid(), "input7"));

            return res;
        }();

        auto generator = QShaderGenerator();
        generator.graph = graph;
        generator.format = gl4;

        const auto code = generator.createShaderCode({"diffuseUniform", "normalUniform"});

        // THEN
        const auto expected = QByteArrayList()
                << "#version 400 core"
                << ""
                << "#define LAYER_diffuseUniform"
                << "#define LAYER_normalUniform"
                << "in vec4 vertexPosition;"
                << "out vec4 fragColor;"
                << ""
                << "void main()"
                << "{"
                << "    fragColor = (((((((vertexPosition*speed + vertexPosition * speed + ((vec4(vertexPosition.xyz,vertexPosition.w))) + ((vec4(vertexPosition.xyz, vertexPosition.w))) + ((vertexPosition.xyzw + vertexPosition)) + ((vertexPosition.xyzw - vertexPosition)) + ((vertexPosition / vertexPosition)))))))));"
                << "}"
                << "";
        QCOMPARE(code, expected.join("\n"));
    }
}

void tst_QShaderGenerator::shouldGenerateTemporariesWisely()
{
    // GIVEN
    const auto gl4 = createFormat(QShaderFormat::OpenGLCoreProfile, 4, 0);

    {
        auto attribute = createNode({
                                        createPort(QShaderNodePort::Output, "vertexPosition")
                                    });
        attribute.addRule(gl4, QShaderNode::Rule("vec4 $vertexPosition = vertexPosition;",
                                                 QByteArrayList() << "in vec4 vertexPosition;"));

        auto complexFunction = createNode({
                                              createPort(QShaderNodePort::Input, "inputVarName"),
                                              createPort(QShaderNodePort::Output, "out")
                                          });
        complexFunction.addRule(gl4, QShaderNode::Rule("vec4 $out = $inputVarName * 2.0;"));

        auto complexFunction2 = createNode({
                                              createPort(QShaderNodePort::Input, "inputVarName"),
                                              createPort(QShaderNodePort::Output, "out")
                                          });
        complexFunction2.addRule(gl4, QShaderNode::Rule("vec4 $out = $inputVarName * 4.0;"));

        auto complexFunction3 = createNode({
                                               createPort(QShaderNodePort::Input, "a"),
                                               createPort(QShaderNodePort::Input, "b"),
                                               createPort(QShaderNodePort::Output, "out")
                                           });
        complexFunction3.addRule(gl4, QShaderNode::Rule("vec4 $out = $a + $b;"));

        auto shaderOutput1 = createNode({
                                            createPort(QShaderNodePort::Input, "input")
                                        });

        shaderOutput1.addRule(gl4, QShaderNode::Rule("shaderOutput1 = $input;",
                                                     QByteArrayList() << "out vec4 shaderOutput1;"));

        auto shaderOutput2 = createNode({
                                            createPort(QShaderNodePort::Input, "input")
                                        });

        shaderOutput2.addRule(gl4, QShaderNode::Rule("shaderOutput2 = $input;",
                                                     QByteArrayList() << "out vec4 shaderOutput2;"));

        {
            // WHEN
            const auto graph = [=] {
                auto res = QShaderGraph();

                res.addNode(attribute);
                res.addNode(complexFunction);
                res.addNode(shaderOutput1);

                res.addEdge(createEdge(attribute.uuid(), "vertexPosition", complexFunction.uuid(), "inputVarName"));
                res.addEdge(createEdge(complexFunction.uuid(), "out", shaderOutput1.uuid(), "input"));

                return res;
            }();

            auto generator = QShaderGenerator();
            generator.graph = graph;
            generator.format = gl4;

            const auto code = generator.createShaderCode();

            // THEN
            const auto expected = QByteArrayList()
                    << "#version 400 core"
                    << ""
                    << "in vec4 vertexPosition;"
                    << "out vec4 shaderOutput1;"
                    << ""
                    << "void main()"
                    << "{"
                    << "    shaderOutput1 = vertexPosition * 2.0;"
                    << "}"
                    << "";
            QCOMPARE(code, expected.join("\n"));
        }

        {
            // WHEN
            const auto graph = [=] {
                auto res = QShaderGraph();

                res.addNode(attribute);
                res.addNode(complexFunction);
                res.addNode(shaderOutput1);
                res.addNode(shaderOutput2);

                res.addEdge(createEdge(attribute.uuid(), "vertexPosition", complexFunction.uuid(), "inputVarName"));
                res.addEdge(createEdge(complexFunction.uuid(), "out", shaderOutput1.uuid(), "input"));
                res.addEdge(createEdge(complexFunction.uuid(), "out", shaderOutput2.uuid(), "input"));

                return res;
            }();

            auto generator = QShaderGenerator();
            generator.graph = graph;
            generator.format = gl4;

            const auto code = generator.createShaderCode();

            // THEN
            const auto expected = QByteArrayList() << "#version 400 core"
                                                   << ""
                                                   << "in vec4 vertexPosition;"
                                                   << "out vec4 shaderOutput2;"
                                                   << "out vec4 shaderOutput1;"
                                                   << ""
                                                   << "void main()"
                                                   << "{"
                                                   << "    vec4 v1 = vertexPosition * 2.0;"
                                                   << "    shaderOutput2 = v1;"
                                                   << "    shaderOutput1 = v1;"
                                                   << "}"
                                                   << "";
            QCOMPARE(code, expected.join("\n"));
        }

        {
            // WHEN
            const auto graph = [=] {
                auto res = QShaderGraph();

                res.addNode(attribute);
                res.addNode(complexFunction);
                res.addNode(complexFunction2);
                res.addNode(complexFunction3);
                res.addNode(shaderOutput1);
                res.addNode(shaderOutput2);

                res.addEdge(createEdge(attribute.uuid(), "vertexPosition", complexFunction.uuid(), "inputVarName"));
                res.addEdge(createEdge(attribute.uuid(), "vertexPosition", complexFunction2.uuid(), "inputVarName"));

                res.addEdge(createEdge(complexFunction.uuid(), "out", complexFunction3.uuid(), "a"));
                res.addEdge(createEdge(complexFunction2.uuid(), "out", complexFunction3.uuid(), "b"));

                res.addEdge(createEdge(complexFunction3.uuid(), "out", shaderOutput1.uuid(), "input"));
                res.addEdge(createEdge(complexFunction2.uuid(), "out", shaderOutput2.uuid(), "input"));

                return res;
            }();

            auto generator = QShaderGenerator();
            generator.graph = graph;
            generator.format = gl4;

            const auto code = generator.createShaderCode();

            // THEN
            const auto expected = QByteArrayList()
                    << "#version 400 core"
                    << ""
                    << "in vec4 vertexPosition;"
                    << "out vec4 shaderOutput2;"
                    << "out vec4 shaderOutput1;"
                    << ""
                    << "void main()"
                    << "{"
                    << "    vec4 v2 = vertexPosition * 4.0;"
                    << "    shaderOutput2 = v2;"
                    << "    shaderOutput1 = (vertexPosition * 2.0 + v2);"
                    << "}"
                    << "";
            QCOMPARE(code, expected.join("\n"));
        }
    }
}

void tst_QShaderGenerator::shouldHandlePortNamesPrefixingOneAnother()
{
    // GIVEN
    const auto gl4 = createFormat(QShaderFormat::OpenGLCoreProfile, 4, 0);

    auto color1 = createNode({
                                 createPort(QShaderNodePort::Output, "output")
                             });
    color1.addRule(gl4, QShaderNode::Rule("vec4 $output = color1;",
                                          QByteArrayList() << "in vec4 color1;"));

    auto color2 = createNode({
                                 createPort(QShaderNodePort::Output, "output")
                             });
    color2.addRule(gl4, QShaderNode::Rule("vec4 $output = color2;",
                                          QByteArrayList() << "in vec4 color2;"));

    auto addColor = createNode({
                                   createPort(QShaderNodePort::Output, "color"),
                                   createPort(QShaderNodePort::Input, "color1"),
                                   createPort(QShaderNodePort::Input, "color2"),
                               });
    addColor.addRule(gl4, QShaderNode::Rule("vec4 $color = $color1 + $color2;"));

    auto shaderOutput = createNode({
                                       createPort(QShaderNodePort::Input, "input")
                                   });

    shaderOutput.addRule(gl4, QShaderNode::Rule("shaderOutput = $input;",
                                                QByteArrayList() << "out vec4 shaderOutput;"));

    // WHEN
    const auto graph = [=] {
        auto res = QShaderGraph();

        res.addNode(color1);
        res.addNode(color2);
        res.addNode(addColor);
        res.addNode(shaderOutput);

        res.addEdge(createEdge(color1.uuid(), "output", addColor.uuid(), "color1"));
        res.addEdge(createEdge(color2.uuid(), "output", addColor.uuid(), "color2"));
        res.addEdge(createEdge(addColor.uuid(), "color", shaderOutput.uuid(), "input"));

        return res;
    }();

    auto generator = QShaderGenerator();
    generator.graph = graph;
    generator.format = gl4;

    const auto code = generator.createShaderCode();

    // THEN
    const auto expected = QByteArrayList() << "#version 400 core"
                                           << ""
                                           << "in vec4 color2;"
                                           << "in vec4 color1;"
                                           << "out vec4 shaderOutput;"
                                           << ""
                                           << "void main()"
                                           << "{"
                                           << "    shaderOutput = ((color1 + color2));"
                                           << "}"
                                           << "";
    QCOMPARE(code, expected.join("\n"));
}

void tst_QShaderGenerator::shouldHandleNodesWithMultipleOutputPorts()
{
    // GIVEN
    const auto gl4 = createFormat(QShaderFormat::OpenGLCoreProfile, 4, 0);

    auto input = createNode({
                                createPort(QShaderNodePort::Output, "output0"),
                                createPort(QShaderNodePort::Output, "output1")
                            });
    input.addRule(gl4, QShaderNode::Rule("vec4 $output0 = globalIn0;"
                                         "float $output1 = globalIn1;",
                                         QByteArrayList() << "in vec4 globalIn0;" << "in float globalIn1;"));

    auto function = createNode({
                                   createPort(QShaderNodePort::Input, "input0"),
                                   createPort(QShaderNodePort::Input, "input1"),
                                   createPort(QShaderNodePort::Output, "output0"),
                                   createPort(QShaderNodePort::Output, "output1")
                               });
    function.addRule(gl4, QShaderNode::Rule("vec4 $output0 = $input0;"
                                            "float $output1 = $input1;"));

    auto output = createNode({
                                 createPort(QShaderNodePort::Input, "input0"),
                                 createPort(QShaderNodePort::Input, "input1")
                             });

    output.addRule(gl4, QShaderNode::Rule("globalOut0 = $input0;"
                                          "globalOut1 = $input1;",
                                          QByteArrayList() << "out vec4 globalOut0;" << "out float globalOut1;"));

    // WHEN
    const auto graph = [=] {
        auto res = QShaderGraph();

        res.addNode(input);
        res.addNode(function);
        res.addNode(output);

        res.addEdge(createEdge(input.uuid(), "output0", function.uuid(), "input0"));
        res.addEdge(createEdge(input.uuid(), "output1", function.uuid(), "input1"));

        res.addEdge(createEdge(function.uuid(), "output0", output.uuid(), "input0"));
        res.addEdge(createEdge(function.uuid(), "output1", output.uuid(), "input1"));

        return res;
    }();

    auto generator = QShaderGenerator();
    generator.graph = graph;
    generator.format = gl4;

    const auto code = generator.createShaderCode();

    // THEN
    const auto expected = QByteArrayList()
            << "#version 400 core"
            << ""
            << "in vec4 globalIn0;"
            << "in float globalIn1;"
            << "out vec4 globalOut0;"
            << "out float globalOut1;"
            << ""
            << "void main()"
            << "{"
            << "    globalOut0 = globalIn0;"
            << "    globalOut1 = globalIn1;"
            << "}"
            << "";
    QCOMPARE(code, expected.join("\n"));
}

void tst_QShaderGenerator::shouldHandleExpressionsInInputNodes()
{
    // GIVEN
    const auto gl4 = createFormat(QShaderFormat::OpenGLCoreProfile, 4, 0);

    auto input = createNode({
                                createPort(QShaderNodePort::Output, "output")
                            });
    input.addRule(gl4, QShaderNode::Rule("float $output = 3 + 4;"));

    auto output = createNode({
                                 createPort(QShaderNodePort::Input, "input")
                             });

    output.addRule(gl4, QShaderNode::Rule("globalOut = $input;",
                                          QByteArrayList() << "out float globalOut;"));

    // WHEN
    const auto graph = [=] {
        auto res = QShaderGraph();

        res.addNode(input);
        res.addNode(output);

        res.addEdge(createEdge(input.uuid(), "output", output.uuid(), "input"));

        return res;
    }();

    auto generator = QShaderGenerator();
    generator.graph = graph;
    generator.format = gl4;

    const auto code = generator.createShaderCode();

    // THEN
    const auto expected = QByteArrayList()
            << "#version 400 core"
            << ""
            << "out float globalOut;"
            << ""
            << "void main()"
            << "{"
            << "    globalOut = 3 + 4;"
            << "}"
            << "";
    QCOMPARE(code, expected.join("\n"));
}

void tst_QShaderGenerator::shouldGenerateLayerDefines()
{
    // GIVEN
    const auto gl4 = createFormat(QShaderFormat::OpenGLCoreProfile, 4, 0);

    auto generator = QShaderGenerator();
    generator.format = gl4;

    // WHEN
    const auto code = generator.createShaderCode({"layer1", "layer2"});

    // THEN
    const auto expected = QByteArrayList()
            << "#version 400 core"
            << ""
            << "#define LAYER_layer1"
            << "#define LAYER_layer2"
            << ""
            << "void main()"
            << "{"
            << "}"
            << "";
    QCOMPARE(code, expected.join("\n"));
}

QTEST_MAIN(tst_QShaderGenerator)

#include "tst_qshadergenerator.moc"
