/*****************************************************************************************
 *                                                                                       *
 * OpenSpace                                                                             *
 *                                                                                       *
 * Copyright (c) 2014-2017                                                               *
 *                                                                                       *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
 * software and associated documentation files (the "Software"), to deal in the Software *
 * without restriction, including without limitation the rights to use, copy, modify,    *
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
 * permit persons to whom the Software is furnished to do so, subject to the following   *
 * conditions:                                                                           *
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 * The above copyright notice and this permission notice shall be included in all copies *
 * or substantial portions of the Software.                                              *
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
 ****************************************************************************************/

#include <modules/digitaluniverse/rendering/renderablebillboardscloud.h>

#include <openspace/documentation/documentation.h>
#include <openspace/documentation/verifier.h>
#include <openspace/util/updatestructures.h>
#include <openspace/engine/openspaceengine.h>
#include <openspace/rendering/renderengine.h>

#include <ghoul/filesystem/filesystem>
#include <ghoul/misc/templatefactory.h>
#include <ghoul/io/texture/texturereader.h>
#include <ghoul/opengl/programobject.h>
#include <ghoul/opengl/texture.h>
#include <ghoul/opengl/textureunit.h>
#include <ghoul/font/fontmanager.h>
#include <ghoul/font/fontrenderer.h>

#include <glm/gtx/string_cast.hpp>
#include <ghoul/glm.h>

#include <array>
#include <fstream>
#include <stdint.h>
#include <locale>
#include <string>

namespace {
    const char* _loggerCat        = "RenderableBillboardsCloud";
    const char* KeyFile           = "File";
    const char* keyColor          = "Color";
    const char* keyUnit           = "Unit";
    const char* MeterUnit         = "m";
    const char* KilometerUnit     = "Km";
    const char* ParsecUnit        = "pc";
    const char* KiloparsecUnit    = "Kpc";
    const char* MegaparsecUnit    = "Mpc";
    const char* GigaparsecUnit    = "Gpc";
    const char* GigalightyearUnit = "Gly";

    const int8_t CurrentCacheVersion = 1;
    const double PARSEC = 0.308567756E17;

    static const openspace::properties::Property::PropertyInfo SpriteTextureInfo = {
        "Texture",
        "Point Sprite Texture",
        "The path to the texture that should be used as the point sprite."        
    };

    static const openspace::properties::Property::PropertyInfo TransparencyInfo = {
        "Transparency",
        "Transparency",
        "This value is a multiplicative factor that is applied to the transparency of "
        "all points."
    };

    static const openspace::properties::Property::PropertyInfo ScaleFactorInfo = {
        "ScaleFactor",
        "Scale Factor",
        "This value is used as a multiplicative factor that is applied to the apparent "
        "size of each point."
    };

    static const openspace::properties::Property::PropertyInfo ColorInfo = {
        "Color",
        "Color",
        "This value is used to define the color of the astronomical object."
    };

    static const openspace::properties::Property::PropertyInfo ColorMapInfo = {
        "ColorMap",
        "Color Map File",
        "The path to the color map file of the astronomical object."
    };

    static const openspace::properties::Property::PropertyInfo PolygonSidesInfo = {
        "PolygonSides",
        "Polygon Sides",
        "The number of sides for the polygon used to represent the astronomical object."
    };

    static const openspace::properties::Property::PropertyInfo TextColorInfo = {
        "TextColor",
        "Text Color",
        "The text color for the astronomical object."
    };

    static const openspace::properties::Property::PropertyInfo TextSizeInfo = {
        "TextSize",
        "Text Size",
        "The text size for the astronomical object labels."
    };

    static const openspace::properties::Property::PropertyInfo LabelFileInfo = {
        "LabelFile",
        "Label File",
        "The path to the label file that contains information about the astronomical "
        "objects being rendered."
    };

    static const openspace::properties::Property::PropertyInfo LabelMinSizeInfo = {
        "TextMinSize",
        "Text Min Size",
        "The minimal size (in pixels) of the text for the labels for the astronomical "
        "objects being rendered."
    };

    static const openspace::properties::Property::PropertyInfo DrawElementsInfo = {
        "DrawElements",
        "Draw Elements",
        "Enables/Disables the drawing of the astronomical objects."
    };

    static const openspace::properties::Property::PropertyInfo DrawLabelInfo = {
        "DrawLabels",
        "Draw Labels",
        "Determines whether labels should be drawn or hidden."
    };

    static const openspace::properties::Property::PropertyInfo ColorOptionInfo = {
        "ColorOption",
        "Color Option",
        "This value determines which paramenter is used default color of the "
        "astronomical objects."
    };

    static const openspace::properties::Property::PropertyInfo ColorRangeInfo = {
        "ColorRange",
        "Color Range",
        "This value determines the color ranges for the color parameter of the "
        "astronomical objects."
    };

    static const openspace::properties::Property::PropertyInfo RenderOptionInfo = {
        "RenderOptionInfo",
        "Render Option",
        "Debug option for rendering of billboards and texts."
    };
}  // namespace

namespace openspace {

documentation::Documentation RenderableBillboardsCloud::Documentation() {
    using namespace documentation;
    return {
        "RenderableBillboardsCloud",
        "digitaluniverse_RenderableBillboardsCloud",
        {
            {
                "Type",
                new StringEqualVerifier("RenderableBillboardsCloud"),
                Optional::No
            },
            {
                KeyFile,
                new StringVerifier,
                Optional::Yes,
                "The path to the SPECK file that contains information about the astronomical "
                "object being rendered."
            },
            { 
                keyColor,
                new Vector3Verifier<float>,
                Optional::No,
                "Astronomical Object Color (r,g,b)."
            },
            {
                SpriteTextureInfo.identifier,
                new StringVerifier,
                Optional::Yes,
                SpriteTextureInfo.description
            },
            {
                TransparencyInfo.identifier,
                new DoubleVerifier,
                Optional::No,
                TransparencyInfo.description
            },
            {
                ScaleFactorInfo.identifier,
                new DoubleVerifier,
                Optional::Yes,
                ScaleFactorInfo.description
            },
            {
                ColorMapInfo.identifier,
                new StringVerifier,
                Optional::Yes,
                ColorMapInfo.description
            },
            {
                PolygonSidesInfo.identifier,
                new IntVerifier,
                Optional::Yes,
                PolygonSidesInfo.description
            },
            {
                DrawLabelInfo.identifier,
                new BoolVerifier,
                Optional::Yes,
                DrawLabelInfo.description
            },
            {
                TextColorInfo.identifier,
                new DoubleVector4Verifier,
                Optional::Yes,
                TextColorInfo.description
            },
            {
                TextSizeInfo.identifier,
                new DoubleVerifier,
                Optional::Yes,
                TextSizeInfo.description
            },
            {
                LabelFileInfo.identifier,
                new StringVerifier,
                Optional::Yes,
                LabelFileInfo.description
            },
            {
                LabelMinSizeInfo.identifier,
                new DoubleVerifier,
                Optional::Yes,
                LabelMinSizeInfo.description
            },
            {
                ColorOptionInfo.identifier,
                new StringListVerifier,
                Optional::Yes,
                ColorOptionInfo.description
            },
            {
                ColorRangeInfo.identifier,
                new Vector2ListVerifier<float>,
                Optional::Yes,
                ColorRangeInfo.description
            }
        }
    };
}


RenderableBillboardsCloud::RenderableBillboardsCloud(const ghoul::Dictionary& dictionary)
    : Renderable(dictionary)
    , _hasSpeckFile(false)
    , _dataIsDirty(true)
    , _textColorIsDirty(true)
    , _hasSpriteTexture(false)
    , _spriteTextureIsDirty(true)
    , _hasColorMapFile(false)
    , _hasPolygon(false)
    , _hasLabel(false)
    , _labelDataIsDirty(true)
    , _polygonSides(0)
    , _pTexture(0)
    , _alphaValue(TransparencyInfo, 1.f, 0.f, 1.f)
    , _scaleFactor(ScaleFactorInfo, 1.f, 0.f, 600.f)
    , _pointColor(ColorInfo, glm::vec3(1.f, 0.4f, 0.2f), glm::vec3(0.f, 0.f, 0.f), glm::vec3(1.0f, 1.0f, 1.0f))
    , _spriteTexturePath(SpriteTextureInfo)
    , _textColor(
        TextColorInfo,
        glm::vec4(1.0f, 1.0, 1.0f, 1.f),
        glm::vec4(0.f),
        glm::vec4(1.f)
    )
    , _textSize(TextSizeInfo, 8.0, 0.5, 24.0)
    , _textMinSize(LabelMinSizeInfo, 8.0, 0.5, 24.0)
    , _drawElements(DrawElementsInfo, true)
    , _drawLabels(DrawLabelInfo, false)
    , _colorOption(ColorOptionInfo, properties::OptionProperty::DisplayType::Dropdown)
    , _renderOption(RenderOptionInfo, properties::OptionProperty::DisplayType::Dropdown)
    , _polygonTexture(nullptr)
    , _spriteTexture(nullptr)
    , _program(nullptr)
    , _fontRenderer(nullptr)
    , _font(nullptr)
    , _speckFile("")
    , _colorMapFile("")
    , _labelFile("")
    , _colorOptionString("")
    , _unit(Parsec)
    , _nValuesPerAstronomicalObject(0)
    , _vao(0)
    , _vbo(0)
    , _polygonVao(0)
    , _polygonVbo(0)
{
    using File = ghoul::filesystem::File;

    documentation::testSpecificationAndThrow(
        Documentation(),
        dictionary,
        "RenderableBillboardsCloud"
    );

    if (dictionary.hasKey(KeyFile)) {
        _speckFile = absPath(dictionary.value<std::string>(KeyFile));
        _hasSpeckFile = true;
        _drawElements.onChange([&]() { 
            _hasSpeckFile = _hasSpeckFile == true? false : true; });
        addProperty(_drawElements);
    }

    // DEBUG:
    _renderOption.addOption(0, "Camera View Direction");
    _renderOption.addOption(1, "Camera Position Normal");
    _renderOption.addOption(2, "Screen center Position Normal");
    addProperty(_renderOption);

    if (dictionary.hasKey(keyUnit)) {
        std::string unit = dictionary.value<std::string>(keyUnit);
        if (unit == MeterUnit) {
            _unit = Meter;
        }
        else if (unit == KilometerUnit) {
            _unit = Kilometer;
        } 
        else if (unit == ParsecUnit) {
            _unit = Parsec;
        }
        else if (unit == KiloparsecUnit) {
            _unit = Kiloparsec;
        }
        else if (unit == MegaparsecUnit) {
            _unit = Megaparsec;
        }
        else if (unit == GigaparsecUnit) {
            _unit = Gigaparsec;
        }
        else if (unit == GigalightyearUnit) {
            _unit = GigalightYears;
        }
        else {
            LWARNING("No unit given for RenderableBillboardsCloud. Using meters as units.");
            _unit = Meter;
        }
    }        

    if (dictionary.hasKey(SpriteTextureInfo.identifier)) {
        _spriteTexturePath = absPath(dictionary.value<std::string>(
            SpriteTextureInfo.identifier
            ));
        _spriteTextureFile = std::make_unique<File>(_spriteTexturePath);

        _spriteTexturePath.onChange([&] { _spriteTextureIsDirty = true; });
        _spriteTextureFile->setCallback(
            [&](const File&) { _spriteTextureIsDirty = true; }
        );
        addProperty(_spriteTexturePath);


        _hasSpriteTexture = true;
    }

    if (dictionary.hasKey(ColorMapInfo.identifier)) {
        _colorMapFile = absPath(dictionary.value<std::string>(
            ColorMapInfo.identifier
            ));
        _hasColorMapFile = true;

        if (dictionary.hasKey(ColorOptionInfo.identifier)) {
            ghoul::Dictionary colorOptionDataDic = dictionary.value<ghoul::Dictionary>(
                ColorOptionInfo.identifier
                );
            for (int i = 0; i < static_cast<int>(colorOptionDataDic.size()); ++i) {
                std::string colorMapInUseName(
                    colorOptionDataDic.value<std::string>(std::to_string(i + 1)));
                _colorOption.addOption(i, colorMapInUseName);
                _optionConversionMap.insert({i, colorMapInUseName});
                _colorOptionString = colorMapInUseName;
            }                
        }
        _colorOption.onChange(
            [&] { 
            _dataIsDirty = true; 
            _colorOptionString = _optionConversionMap[_colorOption.value()];
        });
        addProperty(_colorOption);

        if (dictionary.hasKey(ColorRangeInfo.identifier)) {
            ghoul::Dictionary rangeDataDic = dictionary.value<ghoul::Dictionary>(
                ColorRangeInfo.identifier
                );
            for (int i = 0; i < static_cast<int>(rangeDataDic.size()); ++i) {
                _colorRangeData.push_back(
                    rangeDataDic.value<glm::vec2>(std::to_string(i+1)));
            }

        }

    } else if (dictionary.hasKey(keyColor)) {
        _pointColor = dictionary.value<glm::vec3>(keyColor);
        addProperty(_pointColor);
    }

    if (dictionary.hasKey(TransparencyInfo.identifier)) {
        _alphaValue = static_cast<float>(
            dictionary.value<double>(TransparencyInfo.identifier)
            );
    }
    addProperty(_alphaValue);

    if (dictionary.hasKey(ScaleFactorInfo.identifier)) {
        _scaleFactor = static_cast<float>(
            dictionary.value<double>(ScaleFactorInfo.identifier)
            );
    }
    addProperty(_scaleFactor);

    if (dictionary.hasKey(PolygonSidesInfo.identifier)) {
        _polygonSides = static_cast<float>(
            dictionary.value<double>(PolygonSidesInfo.identifier)
            );
        _hasPolygon = true;
    }

    if (dictionary.hasKey(LabelFileInfo.identifier)) {
        if (dictionary.hasKey(DrawLabelInfo.identifier)) {
            _drawLabels = dictionary.value<bool>(DrawLabelInfo.identifier);
        }
        addProperty(_drawLabels);

        _labelFile = absPath(dictionary.value<std::string>(
            LabelFileInfo.identifier
        ));
        _hasLabel = true;

        if (dictionary.hasKey(TextColorInfo.identifier)) {
            _textColor = dictionary.value<glm::vec4>(TextColorInfo.identifier);
            _hasLabel = true;
        }
        _textColor.setViewOption(properties::Property::ViewOptions::Color);
        addProperty(_textColor);
        _textColor.onChange([&]() { _textColorIsDirty = true; });


        if (dictionary.hasKey(TextSizeInfo.identifier)) {
            _textSize = dictionary.value<double>(TextSizeInfo.identifier);
        }
        addProperty(_textSize);

        if (dictionary.hasKey(LabelMinSizeInfo.identifier)) {
            _textMinSize = static_cast<int>(dictionary.value<float>(LabelMinSizeInfo.identifier));
        }
        addProperty(_textMinSize);
    }
}

bool RenderableBillboardsCloud::isReady() const {
    return ((_program != nullptr) && (!_fullData.empty())) || (!_labelData.empty());
}

void RenderableBillboardsCloud::initialize() {
    RenderEngine& renderEngine = OsEng.renderEngine();

    _program = renderEngine.buildRenderProgram("RenderableBillboardsCloud",
        "${MODULE_DIGITALUNIVERSE}/shaders/billboard2_vs.glsl",
        "${MODULE_DIGITALUNIVERSE}/shaders/billboard2_fs.glsl",
        "${MODULE_DIGITALUNIVERSE}/shaders/billboard2_gs.glsl");

    bool success = loadData();
    if (!success) {
        throw ghoul::RuntimeError("Error loading data");
    }

    if (!_colorOptionString.empty()) {
        // Following DU behavior here. The last colormap variable 
        // entry is the one selected by default.
        _colorOption = static_cast<int>(_colorRangeData.size() - 1);
    }

    if (_hasPolygon) {
        createPolygonTexture();
    }

    if (_hasLabel) {
        if (_fontRenderer == nullptr)
            _fontRenderer = std::unique_ptr<ghoul::fontrendering::FontRenderer>(
                ghoul::fontrendering::FontRenderer::createProjectionSubjectText());
        if (_font == nullptr) {
            size_t _fontSize = 30;
            _font = OsEng.fontManager().font("Mono", static_cast<float>(_fontSize),
                ghoul::fontrendering::FontManager::Outline::Yes,
                ghoul::fontrendering::FontManager::LoadGlyphs::No
            );
        }
    }
}

void RenderableBillboardsCloud::deinitialize() {
    glDeleteBuffers(1, &_vbo);
    _vbo = 0;
    glDeleteVertexArrays(1, &_vao);
    _vao = 0;

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

    if (_hasSpriteTexture) {
        _spriteTexture = nullptr;
    }

    if (_hasPolygon) {
        _polygonTexture = nullptr;
        glDeleteTextures(1, &_pTexture);
    }
}

void RenderableBillboardsCloud::renderBillboards(const RenderData& data, const glm::dmat4& modelViewMatrix,
    const glm::dmat4& projectionMatrix, const glm::vec3& orthoRight, const glm::vec3& orthoUp) {
    glDepthMask(false);

    // Saving current OpenGL state
    GLboolean blendEnabled = glIsEnabled(GL_BLEND);
    GLenum blendEquationRGB;
    GLenum blendEquationAlpha;
    GLenum blendDestAlpha;
    GLenum blendDestRGB;
    GLenum blendSrcAlpha;
    GLenum blendSrcRGB;

    glGetIntegerv(GL_BLEND_EQUATION_RGB, &blendEquationRGB);
    glGetIntegerv(GL_BLEND_EQUATION_ALPHA, &blendEquationAlpha);
    glGetIntegerv(GL_BLEND_DST_ALPHA, &blendDestAlpha);
    glGetIntegerv(GL_BLEND_DST_RGB, &blendDestRGB);
    glGetIntegerv(GL_BLEND_SRC_ALPHA, &blendSrcAlpha);
    glGetIntegerv(GL_BLEND_SRC_RGB, &blendSrcRGB);

    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE);
    //glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    _program->activate();

    using IgnoreError = ghoul::opengl::ProgramObject::IgnoreError;
    _program->setIgnoreUniformLocationError(IgnoreError::Yes);

    _program->setUniform("screenSize", glm::vec2(OsEng.renderEngine().renderingResolution()));
    _program->setUniform("projection", projectionMatrix);
    _program->setUniform("modelViewTransform", modelViewMatrix);
    _program->setUniform("modelViewProjectionTransform", glm::dmat4(projectionMatrix) * modelViewMatrix);

    _program->setUniform("cameraPosition", data.camera.positionVec3());
    _program->setUniform("cameraLookUp", data.camera.lookUpVectorWorldSpace());
    _program->setUniform("renderOption", _renderOption.value());
    glm::dvec4 centerScreenWorld = glm::inverse(data.camera.combinedViewMatrix()) * glm::dvec4(0.0, 0.0, 0.0, 1.0);
    _program->setUniform("centerScreenInWorldPosition", centerScreenWorld);

    _program->setUniform("minBillboardSize", 1.f); // in pixels
    _program->setUniform("color", _pointColor);
    _program->setUniform("sides", 4);
    _program->setUniform("alphaValue", _alphaValue);
    _program->setUniform("scaleFactor", _scaleFactor);

    _program->setUniform("up", orthoUp);
    _program->setUniform("right", orthoRight);

    ghoul::opengl::TextureUnit spriteTextureUnit;
    if (_hasSpriteTexture) {
        spriteTextureUnit.activate();
        _spriteTexture->bind();
        _program->setUniform("spriteTexture", spriteTextureUnit);
    }

    ghoul::opengl::TextureUnit polygonTextureUnit;
    if (_hasPolygon) {
        polygonTextureUnit.activate();
        glBindTexture(GL_TEXTURE_2D, _pTexture);
        _program->setUniform("polygonTexture", polygonTextureUnit);
        _program->setUniform("hasPolygon", _hasPolygon);
    }


    if (_hasColorMapFile) {
        _program->setUniform("hasColorMap", true);
    }
    else {
        _program->setUniform("hasColorMap", false);
    }

    glBindVertexArray(_vao);
    const GLsizei nAstronomicalObjects = static_cast<GLsizei>(_fullData.size() / _nValuesPerAstronomicalObject);
    glDrawArrays(GL_POINTS, 0, nAstronomicalObjects);

    glBindVertexArray(0);
    using IgnoreError = ghoul::opengl::ProgramObject::IgnoreError;
    _program->setIgnoreUniformLocationError(IgnoreError::No);
    _program->deactivate();

    // Restores blending state
    glBlendEquationSeparate(blendEquationRGB, blendEquationAlpha);
    glBlendFuncSeparate(blendSrcRGB, blendDestRGB, blendSrcAlpha, blendDestAlpha);

    if (!blendEnabled) {
        glDisable(GL_BLEND);
    }

    glDepthMask(true);

}

void RenderableBillboardsCloud::renderLabels(const RenderData& data, const glm::dmat4& modelViewProjectionMatrix,
    const glm::vec3& orthoRight, const glm::vec3& orthoUp) {
    RenderEngine& renderEngine = OsEng.renderEngine();

    _fontRenderer->setFramebufferSize(renderEngine.renderingResolution());

    float scale = 0.0;
    switch (_unit) {
    case Meter:
        scale = 1.0;
        break;
    case Kilometer:
        scale = 1e3;
        break;
    case Parsec:
        scale = PARSEC;
        break;
    case Kiloparsec:
        scale = 1e3 * PARSEC;
        break;
    case Megaparsec:
        scale = 1e6 * PARSEC;
        break;
    case Gigaparsec:
        scale = 1e9 * PARSEC;
        break;
    case GigalightYears:
        scale = 306391534.73091 * PARSEC;
        break;
    }

    for (const std::pair<glm::vec3, std::string>& pair : _labelData) {
        //glm::vec3 scaledPos(_transformationMatrix * glm::dvec4(pair.first, 1.0));
        glm::vec3 scaledPos(pair.first);
        scaledPos *= scale;
        _fontRenderer->render(
            *_font,
            scaledPos,
            _textColor,
            pow(10.0, _textSize.value()),
            _textMinSize,
            modelViewProjectionMatrix,
            orthoRight,
            orthoUp,
            data.camera.positionVec3(),
            data.camera.lookUpVectorWorldSpace(),
            _renderOption.value(),
            "%s",
            pair.second.c_str());
    }
}

void RenderableBillboardsCloud::render(const RenderData& data, RendererTasks&) {
    glm::dmat4 modelMatrix =
        glm::translate(glm::dmat4(1.0), data.modelTransform.translation) * // Translation
        glm::dmat4(data.modelTransform.rotation) *  // Spice rotation
        glm::scale(glm::dmat4(1.0), glm::dvec3(data.modelTransform.scale));

    glm::dmat4 modelViewMatrix = data.camera.combinedViewMatrix() * modelMatrix;
    // glm::mat4 viewMatrix = data.camera.viewMatrix();
    glm::mat4 projectionMatrix = data.camera.projectionMatrix();
    glm::dmat4 modelViewProjectionMatrix = glm::dmat4(projectionMatrix) * modelViewMatrix;

    glm::vec3 lookup = data.camera.lookUpVectorWorldSpace();
    glm::vec3 viewDirection = data.camera.viewDirectionWorldSpace();
    glm::vec3 right = glm::cross(viewDirection, lookup);
    glm::vec3 up = glm::cross(right, viewDirection);

    glm::dmat4 worldToModelTransform = glm::inverse(modelMatrix);
    glm::vec3 orthoRight = glm::normalize(glm::vec3(worldToModelTransform * glm::vec4(right, 0.0)));
    glm::vec3 orthoUp = glm::normalize(glm::vec3(worldToModelTransform * glm::vec4(up, 0.0)));


    if (_hasSpeckFile) {
        renderBillboards(data, modelViewMatrix, projectionMatrix, orthoRight, orthoUp);
    }

    if (_drawLabels && _hasLabel) {
        renderLabels(data, modelViewProjectionMatrix, orthoRight, orthoUp);
    }
}

void RenderableBillboardsCloud::update(const UpdateData&) {  
    if (_dataIsDirty && _hasSpeckFile) {
        LDEBUG("Regenerating data");

        createDataSlice();

        int size = static_cast<int>(_slicedData.size());

        if (_vao == 0) {
            glGenVertexArrays(1, &_vao);
            LDEBUG("Generating Vertex Array id '" << _vao << "'");
        }
        if (_vbo == 0) {
            glGenBuffers(1, &_vbo);
            LDEBUG("Generating Vertex Buffer Object id '" << _vbo << "'");
        }

        glBindVertexArray(_vao);
        glBindBuffer(GL_ARRAY_BUFFER, _vbo);
        glBufferData(
            GL_ARRAY_BUFFER,
            size * sizeof(float),
            &_slicedData[0],
            GL_STATIC_DRAW
        );
        GLint positionAttrib = _program->attributeLocation("in_position");

        if (_hasColorMapFile) {

            /*const size_t nAstronomicalObjects = _fullData.size() / _nValuesPerAstronomicalObject;
            const size_t nValues = _slicedData.size() / nAstronomicalObjects;
            GLsizei stride = static_cast<GLsizei>(sizeof(float) * nValues);*/

            glEnableVertexAttribArray(positionAttrib);
            glVertexAttribPointer(
                positionAttrib,
                4,
                GL_FLOAT,
                GL_FALSE,
                sizeof(float)*8,
                nullptr
            );

            GLint colorMapAttrib = _program->attributeLocation("in_colormap");
            glEnableVertexAttribArray(colorMapAttrib);
            glVertexAttribPointer(
                colorMapAttrib,
                4,
                GL_FLOAT,
                GL_FALSE,
                sizeof(float) * 8,
                reinterpret_cast<void*>(sizeof(float)*4)
            );
        }
        else {
            glEnableVertexAttribArray(positionAttrib);
            glVertexAttribPointer(
                positionAttrib,
                4,
                GL_FLOAT,
                GL_FALSE,
                0,
                nullptr
            );
        }

        glBindVertexArray(0);

        _dataIsDirty = false;
    }

    if (_hasSpriteTexture && _spriteTextureIsDirty) {
        LDEBUG("Reloading Sprite Texture");
        _spriteTexture = nullptr;
        if (_spriteTexturePath.value() != "") {
            _spriteTexture = ghoul::io::TextureReader::ref().loadTexture(absPath(_spriteTexturePath));
            if (_spriteTexture) {
                LDEBUG("Loaded texture from '" << absPath(_spriteTexturePath) << "'");
                _spriteTexture->uploadTexture();
            }
            _spriteTexture->setFilter(ghoul::opengl::Texture::FilterMode::AnisotropicMipMap);

            _spriteTextureFile = std::make_unique<ghoul::filesystem::File>(
                _spriteTexturePath);
            _spriteTextureFile->setCallback(
                [&](const ghoul::filesystem::File&) { _spriteTextureIsDirty = true; }
                );
        }
        _spriteTextureIsDirty = false;
    }

    if (_hasLabel && _labelDataIsDirty) {
        _labelDataIsDirty = false;
    }
}

bool RenderableBillboardsCloud::loadData() {
    bool success = false; 
    if (_hasSpeckFile) {
        std::string _file = _speckFile;
        // I disabled the cache as it didn't work on Mac --- abock

        // std::string cachedFile = FileSys.cacheManager()->cachedFilename(
        //     _file,
        //     ghoul::filesystem::CacheManager::Persistent::Yes
        // );

        // bool hasCachedFile = FileSys.fileExists(cachedFile);
        // if (hasCachedFile) {
        //     LINFO("Cached file '" << cachedFile << "' used for Speck file '" << _file << "'");

        //     success = loadCachedFile(cachedFile);
        //     if (!success) {
        //         FileSys.cacheManager()->removeCacheFile(_file);
        //         // Intentional fall-through to the 'else' computation to generate the cache
        //         // file for the next run
        //     }
        // }
        // else 
        // {
        //     LINFO("Cache for Speck file '" << _file << "' not found");
            LINFO("Loading Speck file '" << _file << "'");

            success = readSpeckFile();
            if (!success) {
                return false;
            }

            // LINFO("Saving cache");
            // success &= saveCachedFile(cachedFile);
        // }
    }

    if (_hasColorMapFile) {
        if (!_hasSpeckFile)
            success = true;
        success &= readColorMapFile();
    }

    std::string labelFile = _labelFile;
    if (!labelFile.empty()) {
        // I disabled the cache as it didn't work on Mac --- abock
        // std::string cachedFile = FileSys.cacheManager()->cachedFilename(
        //     labelFile,
        //     ghoul::filesystem::CacheManager::Persistent::Yes
        // );
        if (!_hasSpeckFile && !_hasColorMapFile)
            success = true;
        //bool hasCachedFile = FileSys.fileExists(cachedFile);
        //if (hasCachedFile) {
        //    LINFO("Cached file '" << cachedFile << "' used for Label file '" << labelFile << "'");
        //    
        //    success &= loadCachedFile(cachedFile);
        //    if (!success) {
        //        FileSys.cacheManager()->removeCacheFile(labelFile);
        //        // Intentional fall-through to the 'else' computation to generate the cache
        //        // file for the next run
        //    }
        //}
        //else 
        // {
            // LINFO("Cache for Label file '" << labelFile << "' not found");
            LINFO("Loading Label file '" << labelFile << "'");

            success &= readLabelFile();
            if (!success) {
                return false;
            }

        // }
    }

    return success;
}

bool RenderableBillboardsCloud::readSpeckFile() {
    std::string _file = _speckFile;
    std::ifstream file(_file);
    if (!file.good()) {
        LERROR("Failed to open Speck file '" << _file << "'");
        return false;
    }

    _nValuesPerAstronomicalObject = 0;

    // The beginning of the speck file has a header that either contains comments
    // (signaled by a preceding '#') or information about the structure of the file
    // (signaled by the keywords 'datavar', 'texturevar', and 'texture')
    std::string line = "";
    while (true) {
        std::streampos position = file.tellg();
        std::getline(file, line);

        // Guard against wrong line endings (copying files from Windows to Mac) causes
        // lines to have a final \r 
        if (!line.empty() && line.back() == '\r') {
            line = line.substr(0, line.length() -1);
        }

        if (line.empty() || line[0] == '#') {
            continue;
        }

        if (line.substr(0, 7) != "datavar" &&
            line.substr(0, 10) != "texturevar" &&
            line.substr(0, 7) != "texture" &&
            line.substr(0, 10) != "polyorivar" &&
            line.substr(0, 10) != "maxcomment")
        {
            // we read a line that doesn't belong to the header, so we have to jump back
            // before the beginning of the current line
            file.seekg(position);
            break;
        }

        if (line.substr(0, 7) == "datavar") {
            // datavar lines are structured as follows:
            // datavar # description
            // where # is the index of the data variable; so if we repeatedly overwrite
            // the 'nValues' variable with the latest index, we will end up with the total
            // number of values (+3 since X Y Z are not counted in the Speck file index)
            std::stringstream str(line);

            std::string dummy; 
            str >> dummy; // command
            str >> _nValuesPerAstronomicalObject; // variable index
            dummy.clear();
            str >> dummy; // variable name

            _variableDataPositionMap.insert({ dummy, _nValuesPerAstronomicalObject });                

            _nValuesPerAstronomicalObject += 1; // We want the number, but the index is 0 based
        }
    }

    _nValuesPerAstronomicalObject += 3; // X Y Z are not counted in the Speck file indices

    do {
        std::vector<float> values(_nValuesPerAstronomicalObject);

        std::getline(file, line);

        // Guard against wrong line endings (copying files from Windows to Mac) causes
        // lines to have a final \r 
        if (!line.empty() && line.back() == '\r') {
            line = line.substr(0, line.length() -1);
        }

        if (line.empty()) {
            continue;
        }

        std::stringstream str(line);

        for (int i = 0; i < _nValuesPerAstronomicalObject; ++i) {
            str >> values[i];
        }

        _fullData.insert(_fullData.end(), values.begin(), values.end());
    } while (!file.eof());

    return true;
}

bool RenderableBillboardsCloud::readColorMapFile() {
    std::string _file = _colorMapFile;
    std::ifstream file(_file);
    if (!file.good()) {
        LERROR("Failed to open Color Map file '" << _file << "'");
        return false;
    }

    int numberOfColors = 0;

    // The beginning of the speck file has a header that either contains comments
    // (signaled by a preceding '#') or information about the structure of the file
    // (signaled by the keywords 'datavar', 'texturevar', and 'texture')
    std::string line = "";
    while (true) {
        // std::streampos position = file.tellg();
        std::getline(file, line);

        if (line[0] == '#' || line.empty()) {
            continue;
        }

        // Initial number of colors
        std::locale loc;
        if (std::isdigit(line[0], loc)) {
            std::string::size_type sz;
            numberOfColors = static_cast<int>(std::stoi(line, &sz));
            break;
        }
        else if (file.eof()) {
            return false;
        }
    }

    for (int i = 0; i < numberOfColors; ++i) {
        std::getline(file, line);
        std::stringstream str(line);

        glm::vec4 color;
        for (auto j = 0; j < 4; ++j) {
            str >> color[j];
        }

        _colorMapData.push_back(color);
    }

    return true;
}

bool RenderableBillboardsCloud::readLabelFile() {
    std::string _file = _labelFile;
    std::ifstream file(_file);
    if (!file.good()) {
        LERROR("Failed to open Label file '" << _file << "'");
        return false;
    }

    // The beginning of the speck file has a header that either contains comments
    // (signaled by a preceding '#') or information about the structure of the file
    // (signaled by the keywords 'datavar', 'texturevar', and 'texture')
    std::string line = "";
    while (true) {
        std::streampos position = file.tellg();
        std::getline(file, line);

        // Guard against wrong line endings (copying files from Windows to Mac) causes
        // lines to have a final \r 
        if (!line.empty() && line.back() == '\r') {
            line = line.substr(0, line.length() -1);
        }

        if (line.empty() || line[0] == '#') {
            continue;
        }

        if (line.substr(0, 9) != "textcolor") {
            // we read a line that doesn't belong to the header, so we have to jump back
            // before the beginning of the current line
            file.seekg(position);
            continue;
        }

        if (line.substr(0, 9) == "textcolor") {
            // textcolor lines are structured as follows:
            // textcolor # description
            // where # is color text defined in configuration file
            std::stringstream str(line);

            // TODO: handle cases of labels with different colors
            break;
        }
    }


    do {
        std::vector<float> values(_nValuesPerAstronomicalObject);

        std::getline(file, line);

        // Guard against wrong line endings (copying files from Windows to Mac) causes
        // lines to have a final \r 
        if (!line.empty() && line.back() == '\r') {
            line = line.substr(0, line.length() -1);
        }

        if (line.empty()) {
            continue;
        }

        std::stringstream str(line);

        glm::vec3 position;
        for (auto j = 0; j < 3; ++j) {
            str >> position[j];
        }

        std::string dummy;
        str >> dummy; // text keyword

        std::string label;
        str >> label;
        dummy.clear();

        while (str >> dummy) {
            label += " " + dummy;
            dummy.clear();
        }

        _labelData.push_back(std::make_pair(position, label));

    } while (!file.eof());

    return true;
}

bool RenderableBillboardsCloud::loadCachedFile(const std::string& file) {
    std::ifstream fileStream(file, std::ifstream::binary);
    if (fileStream.good()) {
        int8_t version = 0;
        fileStream.read(reinterpret_cast<char*>(&version), sizeof(int8_t));
        if (version != CurrentCacheVersion) {
            LINFO("The format of the cached file has changed: deleting old cache");
            fileStream.close();
            FileSys.deleteFile(file);
            return false;
        }

        int32_t nValues = 0;
        fileStream.read(reinterpret_cast<char*>(&nValues), sizeof(int32_t));
        fileStream.read(reinterpret_cast<char*>(&_nValuesPerAstronomicalObject), sizeof(int32_t));

        _fullData.resize(nValues);
        fileStream.read(reinterpret_cast<char*>(&_fullData[0]),
            nValues * sizeof(_fullData[0]));

        if (_hasColorMapFile) {
            int32_t nItems = 0;
            fileStream.read(reinterpret_cast<char*>(&nItems), sizeof(int32_t));

            for (int i = 0; i < nItems; ++i) {
                int32_t keySize = 0;
                fileStream.read(reinterpret_cast<char*>(&keySize), sizeof(int32_t));
                std::string key;
                for (int c = 0; c < keySize; ++c) {
                    char t[2];
                    t[1] = '\0';
                    fileStream.read(reinterpret_cast<char*>(&t), sizeof(int32_t));
                    key.append(t);
                }
                int32_t value = 0;
                fileStream.read(reinterpret_cast<char*>(&value), sizeof(int32_t));

                _variableDataPositionMap.insert({ key, value });
            }
        }

        bool success = fileStream.good();
        return success;
    }
    else {
        LERROR("Error opening file '" << file << "' for loading cache file");
        return false;
    }
}

bool RenderableBillboardsCloud::saveCachedFile(const std::string& file) const {
    std::ofstream fileStream(file, std::ofstream::binary);
    if (fileStream.good()) {
        fileStream.write(reinterpret_cast<const char*>(&CurrentCacheVersion),
            sizeof(int8_t));

        int32_t nValues = static_cast<int32_t>(_fullData.size());
        if (nValues == 0) {
            LERROR("Error writing cache: No values were loaded");
            return false;
        }
        fileStream.write(reinterpret_cast<const char*>(&nValues), sizeof(int32_t));

        int32_t nValuesPerAstronomicalObject = static_cast<int32_t>(_nValuesPerAstronomicalObject);
        fileStream.write(reinterpret_cast<const char*>(&nValuesPerAstronomicalObject), sizeof(int32_t));            

        size_t nBytes = nValues * sizeof(_fullData[0]);
        fileStream.write(reinterpret_cast<const char*>(&_fullData[0]), nBytes);

        if (_hasColorMapFile) {
            int32_t nItems = static_cast<int32_t>(_variableDataPositionMap.size());
            fileStream.write(reinterpret_cast<const char*>(&nItems), sizeof(int32_t));

            for (auto pair : _variableDataPositionMap) {
                int32_t keySize = static_cast<int32_t>(pair.first.size());
                fileStream.write(reinterpret_cast<const char*>(&keySize), sizeof(int32_t));
                for (int c = 0; c < static_cast<int>(pair.first.size()); ++c) {
                    int32_t keyChar = static_cast<int32_t>(pair.first[c]);
                    fileStream.write(reinterpret_cast<const char*>(&keyChar), sizeof(int32_t));
                }
                int32_t value = static_cast<int32_t>(pair.second);
                fileStream.write(reinterpret_cast<const char*>(&value), sizeof(int32_t));
            }
        }

        bool success = fileStream.good();
        return success;
    }
    else {
        LERROR("Error opening file '" << file << "' for save cache file");
        return false;
    }
}

void RenderableBillboardsCloud::createDataSlice() {
    _slicedData.clear();
    if (_hasColorMapFile) {
        _slicedData.reserve(8 * (_fullData.size() / _nValuesPerAstronomicalObject));
    }
    else {
        _slicedData.reserve(4 * (_fullData.size()/_nValuesPerAstronomicalObject));
    }

    // Generate the color bins for the colomap
    int colorMapInUse = 0;
    std::vector<float> colorBins;
    if (_hasColorMapFile) {
        colorMapInUse = _variableDataPositionMap[_colorOptionString];
        glm::vec2 currentColorRange = _colorRangeData[_colorOption.value()];
        float colorMapBinSize = (currentColorRange.y - currentColorRange.x) / static_cast<float>(_colorMapData.size());            
        float bin = colorMapBinSize;
        for (int i = 0; i < static_cast<int>(_colorMapData.size()); ++i) {
            colorBins.push_back(bin);
            bin += colorMapBinSize;
        }
    }

    for (size_t i = 0; i < _fullData.size(); i += _nValuesPerAstronomicalObject) { 
        glm::dvec4 transformedPos = glm::dvec4(_fullData[i + 0], _fullData[i + 1], _fullData[i + 2], 1.0);
        glm::vec4 position(glm::vec3(transformedPos), static_cast<float>(_unit));

        if (_hasColorMapFile) {
            for (int j = 0; j < 4; ++j) {
                _slicedData.push_back(position[j]);
            }
            // Finds from which bin to get the color.
            // Note: the first color in the colormap file
            // is the outliers color.
            glm::vec4 itemColor;
            float variableColor = _fullData[i + 3 + colorMapInUse];
            int c = static_cast<int>(colorBins.size() - 1);
            // Float vs int comparison?
            while (variableColor < colorBins[c]) {
                --c;
                if (c == 0)
                    break;
            }

            int colorIndex = 0;
            if (c != static_cast<int>(colorBins.size() - 1)) {
                colorIndex = c + 1;
            }

            for (auto j = 0; j < 4; ++j) {
                _slicedData.push_back(_colorMapData[colorIndex][j]);
            }
        }
        else {
            for (auto j = 0; j < 4; ++j) {
                _slicedData.push_back(position[j]);
            }
        }
    }
}

void RenderableBillboardsCloud::createPolygonTexture() {
    LDEBUG("Creating Polygon Texture");

    glGenTextures(1, &_pTexture);
    glBindTexture(GL_TEXTURE_2D, _pTexture);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    // Stopped using a buffer object for GL_PIXEL_UNPACK_BUFFER
    glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 256,
        256, 0, GL_RGBA, GL_BYTE, nullptr);

    renderToTexture(std::bind(&openspace::RenderableBillboardsCloud::loadPolygonGeometryForRendering, 
        this),
        std::bind(&openspace::RenderableBillboardsCloud::renderPolygonGeometry, 
        this, std::placeholders::_1),
        _pTexture, 256, 256);
}

void RenderableBillboardsCloud::renderToTexture(
    std::function<void(void)> geometryLoadingFunction,
    std::function<void(GLuint)> renderFunction,
    GLuint textureToRenderTo, GLuint textureWidth, GLuint textureHeight) {
    LDEBUG("Rendering to Texture");

    // Saves initial Application's OpenGL State
    GLint defaultFBO;
    GLint viewport[4];
    glGetIntegerv(GL_FRAMEBUFFER_BINDING, &defaultFBO);
    glGetIntegerv(GL_VIEWPORT, viewport);

    GLuint textureFBO;
    glGenFramebuffers(1, &textureFBO);
    glBindFramebuffer(GL_FRAMEBUFFER, textureFBO);
    GLenum drawBuffers[1] = { GL_COLOR_ATTACHMENT0 };
    glDrawBuffers(1, drawBuffers);

    glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, textureToRenderTo, 0);

    glViewport(0, 0, textureWidth, textureHeight);

    geometryLoadingFunction();
    renderFunction(_polygonVao);

    // Restores Applications' OpenGL State
    glBindFramebuffer(GL_FRAMEBUFFER, defaultFBO);
    glViewport(viewport[0], viewport[1], viewport[2], viewport[3]);

    if (_polygonVbo) {
        glDeleteBuffers(1, &_polygonVbo);
    }

    if (_polygonVao) {
        glDeleteVertexArrays(1, &_polygonVao);
    }
    glDeleteFramebuffers(1, &textureFBO);
}

void RenderableBillboardsCloud::loadPolygonGeometryForRendering() {
    glGenVertexArrays(1, &_polygonVao);
    glGenBuffers(1, &_polygonVbo);
    glBindVertexArray(_polygonVao);
    glBindBuffer(GL_ARRAY_BUFFER, _polygonVbo);

    const GLfloat vertex_data[] = {
        //      x      y     z     w
        0.0f, 0.0f, 0.0f, 1.0f,
    };

    glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_data), vertex_data, GL_STATIC_DRAW);
    glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 4, reinterpret_cast<GLvoid*>(0));
    glEnableVertexAttribArray(0);
    glBindVertexArray(0);
}

void RenderableBillboardsCloud::renderPolygonGeometry(GLuint vao) {
    std::unique_ptr<ghoul::opengl::ProgramObject> program = 
        ghoul::opengl::ProgramObject::Build("RenderableBillboardsCloud_Polygon",
        "${MODULE_DIGITALUNIVERSE}/shaders/billboardpolygon_vs.glsl",
        "${MODULE_DIGITALUNIVERSE}/shaders/billboardpolygon_fs.glsl",
        "${MODULE_DIGITALUNIVERSE}/shaders/billboardpolygon_gs.glsl");

    program->activate();
    static const float black[] = { 0.0f, 0.0f, 0.0f, 0.0f };
    glClearBufferfv(GL_COLOR, 0, black);

    program->setUniform("sides", _polygonSides);
    program->setUniform("polygonColor", _pointColor);

    glBindVertexArray(vao);
    glDrawArrays(GL_POINTS, 0, 1);
    glBindVertexArray(0);

    program->deactivate();
}

} // namespace openspace