/*****************************************************************************************
 *                                                                                       *
 * OpenSpace                                                                             *
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 * Copyright (c) 2014-2017                                                               *
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#include <modules/base/rendering/renderableplane.h>

#include <openspace/documentation/documentation.h>
#include <openspace/documentation/verifier.h>
#include <openspace/engine/configurationmanager.h>
#include <openspace/engine/openspaceengine.h>
#include <openspace/util/powerscaledcoordinate.h>

#include <openspace/scene/scenegraphnode.h>
#include <openspace/rendering/renderengine.h>
#include <modules/newhorizons/rendering/renderableplanetprojection.h>

#include <ghoul/filesystem/filesystem>
#include <ghoul/io/texture/texturereader.h>
#include <ghoul/opengl/programobject.h>
#include <ghoul/opengl/texture.h>
#include <ghoul/opengl/textureunit.h>

namespace {
    const char* KeySize = "Size";
    const char* KeyBillboard = "Billboard";
    const char* KeyBlendMode = "BlendMode";
    const char* KeyTexture = "Texture";


    const char* keyFieldlines = "Fieldlines";
    const char* keyFilename = "File";
    const char* keyHints = "Hints";
    const char* keyShaders = "Shaders";
    const char* keyVertexShader = "VertexShader";
    const char* keyFragmentShader = "FragmentShader";
} // namespace

namespace openspace {

documentation::Documentation RenderablePlane::Documentation() {
    using namespace documentation;
    return {
        "Renderable Plane",
        "base_renderable_plane",
        {
            {
                KeySize,
                new DoubleVerifier,
                "Specifies the size of the square plane in meters.",
                Optional::No
            },
            {
                KeyBillboard,
                new BoolVerifier,
                "Specifies whether the plane is a billboard, which means that it is "
                "always facing the camera. If this is false, it can be oriented using "
                "other transformations. The default is 'false'.",
                Optional::Yes
            },
            {
                KeyBlendMode,
                new StringInListVerifier({ "Normal", "Additive" }),
                "Specifies the blend mode that is applied to this plane. The default "
                "value is 'Normal'.",
                Optional::Yes
            },
            {
                KeyTexture,
                new StringVerifier,
                "Specifies the texture that is applied to this plane. This image has to "
                "be a square image.",
                Optional::No
            }
        }
    };
}


RenderablePlane::RenderablePlane(const ghoul::Dictionary& dictionary)
    : Renderable(dictionary)
    , _texturePath("texture", "Texture")
    , _billboard("billboard", "Billboard", false)
    , _size("size", "Size", 10, 0, std::pow(10, 25))
    , _shader(nullptr)
    , _textureIsDirty(false)
    , _texture(nullptr)
    , _blendMode(BlendMode::Normal)
    , _quad(0)
    , _vertexPositionBuffer(0)
{
    documentation::testSpecificationAndThrow(
        Documentation(),
        dictionary,
        "RenderablePlane"
    );

    _size = dictionary.value<double>(KeySize);

    if (dictionary.hasKey(KeyBillboard)) {
        _billboard = dictionary.value<bool>(KeyBillboard);
    }

    if (dictionary.hasKey(KeyBlendMode)) {
        const std::string v = dictionary.value<std::string>(KeyBlendMode);
        if (v == "Normal") {
            _blendMode = BlendMode::Normal;
        }
        else if (v == "Additive") {
            _blendMode = BlendMode::Additive;
            setRenderBin(Renderable::RenderBin::Transparent);
        }
    }
    _texturePath = absPath(dictionary.value<std::string>(KeyTexture));
    _textureFile = new ghoul::filesystem::File(_texturePath);

    addProperty(_billboard);
    addProperty(_texturePath);
    _texturePath.onChange([this]() {loadTexture(); });
    _textureFile->setCallback(
        [this](const ghoul::filesystem::File&) { _textureIsDirty = true; }
    );

    addProperty(_size);
    _size.onChange([this](){ _planeIsDirty = true; });

    setBoundingSphere(_size);
}

RenderablePlane::~RenderablePlane() {
    delete _textureFile;
    _textureFile = nullptr;
}

bool RenderablePlane::isReady() const {
    return _shader && _texture;
}

bool RenderablePlane::initialize() {
    glGenVertexArrays(1, &_quad); // generate array
    glGenBuffers(1, &_vertexPositionBuffer); // generate buffer
    createPlane();

    _shader = OsEng.renderEngine().buildRenderProgram("PlaneProgram",
        "${MODULE_BASE}/shaders/plane_vs.glsl",
        "${MODULE_BASE}/shaders/plane_fs.glsl"
        );

    loadTexture();

    return isReady();
}

bool RenderablePlane::deinitialize() {
    glDeleteVertexArrays(1, &_quad);
    _quad = 0;

    glDeleteBuffers(1, &_vertexPositionBuffer);
    _vertexPositionBuffer = 0;

    delete _textureFile;
    _textureFile = nullptr;

    RenderEngine& renderEngine = OsEng.renderEngine();
    if (_shader) {
        renderEngine.removeRenderProgram(_shader);
        _shader = nullptr;
    }

    return true;
}

void RenderablePlane::render(const RenderData& data) {
    glm::mat4 scaleTransform = glm::mat4(1.0);
    
    // Activate shader
    _shader->activate();
    //if (_projectionListener){
    //    //get parent node-texture and set with correct dimensions  
    //    SceneGraphNode* textureNode = OsEng.renderEngine().scene()->sceneGraphNode(_nodeName)->parent();
    //    if (textureNode != nullptr){
    //        RenderablePlanetProjection* t = static_cast<RenderablePlanetProjection*>(textureNode->renderable());
    //        _texture = std::unique_ptr<ghoul::opengl::Texture>(&(t->baseTexture()));
    //        unsigned int h = _texture->height();
    //        unsigned int w = _texture->width();
    //        float scale = static_cast<float>(h) / static_cast<float>(w);
    //        scaleTransform = glm::scale(glm::mat4(1.0), glm::vec3(1.f, scale, 1.f));
    //    }
    //}

    // Model transform and view transform needs to be in double precision
    glm::dmat4 rotationTransform;
    if (_billboard) {
        rotationTransform = glm::inverse(glm::dmat4(data.camera.viewRotationMatrix()));
    }
    else {
        rotationTransform = glm::dmat4(data.modelTransform.rotation);
    }

    glm::dmat4 modelTransform =
        glm::translate(glm::dmat4(1.0), data.modelTransform.translation) *
        rotationTransform *
        glm::dmat4(glm::scale(glm::dmat4(1.0), glm::dvec3(data.modelTransform.scale))) *
        glm::dmat4(scaleTransform);
    glm::dmat4 modelViewTransform = data.camera.combinedViewMatrix() * modelTransform;

    _shader->setUniform("modelViewProjectionTransform",
        data.camera.projectionMatrix() * glm::mat4(modelViewTransform));
    
    //_shader->setUniform("ViewProjection", data.camera.viewProjectionMatrix());
    //_shader->setUniform("ModelTransform", transform);
    //setPscUniforms(*_shader.get(), data.camera, data.position);

    ghoul::opengl::TextureUnit unit;
    unit.activate();
    _texture->bind();
    _shader->setUniform("texture1", unit);

    bool usingFramebufferRenderer =
        OsEng.renderEngine().rendererImplementation() == RenderEngine::RendererImplementation::Framebuffer;

    bool usingABufferRenderer =
        OsEng.renderEngine().rendererImplementation() == RenderEngine::RendererImplementation::ABuffer;

    if (usingABufferRenderer) {
        _shader->setUniform("additiveBlending", _blendMode == BlendMode::Additive);
    }

    bool additiveBlending = _blendMode == BlendMode::Additive && usingFramebufferRenderer;
    if (additiveBlending) {
        glDepthMask(false);
        glBlendFunc(GL_SRC_ALPHA, GL_ONE);
    }

    glBindVertexArray(_quad);
    glDrawArrays(GL_TRIANGLES, 0, 6);

    if (additiveBlending) {
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
        glDepthMask(true);
    }

    _shader->deactivate();
}

void RenderablePlane::update(const UpdateData&) {
    if (_shader->isDirty())
        _shader->rebuildFromFile();

    if (_planeIsDirty)
        createPlane();

    if (_textureIsDirty) {
        loadTexture();
        _textureIsDirty = false;
    }
}

void RenderablePlane::loadTexture() {
    if (_texturePath.value() != "") {
        std::unique_ptr<ghoul::opengl::Texture> texture =
            ghoul::io::TextureReader::ref().loadTexture(absPath(_texturePath));

        if (texture) {
            LDEBUGC(
                "RenderablePlane",
                "Loaded texture from '" << absPath(_texturePath) << "'"
            );
            texture->uploadTexture();

            // Textures of planets looks much smoother with AnisotropicMipMap rather than linear
            texture->setFilter(ghoul::opengl::Texture::FilterMode::Linear);

            _texture = std::move(texture);

            delete _textureFile;
            _textureFile = new ghoul::filesystem::File(_texturePath);
            _textureFile->setCallback([&](const ghoul::filesystem::File&) { _textureIsDirty = true; });
        }
    }
}

void RenderablePlane::createPlane() {
    // ============================
    //         GEOMETRY (quad)
    // ============================
    const GLfloat size = _size;
    const GLfloat vertex_data[] = {
        //      x      y     z     w     s     t
        -size, -size, 0.f, 0.f, 0.f, 0.f,
        size, size, 0.f, 0.f, 1.f, 1.f,
        -size, size, 0.f, 0.f, 0.f, 1.f,
        -size, -size, 0.f, 0.f, 0.f, 0.f,
        size, -size, 0.f, 0.f, 1.f, 0.f,
        size, size, 0.f, 0.f, 1.f, 1.f,
    };

    glBindVertexArray(_quad); // bind array
    glBindBuffer(GL_ARRAY_BUFFER, _vertexPositionBuffer); // bind buffer
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_data), vertex_data, GL_STATIC_DRAW);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 6, reinterpret_cast<void*>(0));
    glEnableVertexAttribArray(1);
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 6, reinterpret_cast<void*>(sizeof(GLfloat) * 4));
}

} // namespace openspace