/*****************************************************************************************
 *                                                                                       *
 * OpenSpace                                                                             *
 *                                                                                       *
 * Copyright (c) 2014-2018                                                               *
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 * 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   *
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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    *
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 ****************************************************************************************/

// @TODO: Clean up this class and make it not copy much code from RenderablePlane ---abock

#include <modules/debugging/rendering/renderabledebugplane.h>

#include <modules/spacecraftinstruments/rendering/renderableplanetprojection.h>
#include <openspace/documentation/documentation.h>
#include <openspace/documentation/verifier.h>
#include <openspace/engine/globals.h>
#include <openspace/rendering/renderengine.h>
#include <openspace/util/updatestructures.h>
#include <ghoul/filesystem/filesystem.h>
#include <ghoul/io/texture/texturereader.h>
#include <ghoul/opengl/programobject.h>
#include <ghoul/opengl/texture.h>
#include <ghoul/opengl/textureunit.h>

namespace {
    enum Origin {
        LowerLeft = 0,
        LowerRight,
        UpperLeft,
        UpperRight,
        Center
    };

    constexpr openspace::properties::Property::PropertyInfo TextureInfo = {
        "Texture",
        "Texture",
        "The OpenGL name of the texture that is displayed on this plane."
    };

    constexpr openspace::properties::Property::PropertyInfo BillboardInfo = {
        "Billboard",
        "Billboard mode",
        "This value 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."
    };

    constexpr openspace::properties::Property::PropertyInfo SizeInfo = {
        "Size",
        "Size (in meters)",
        "This value specifies the size of the plane in meters."
    };

    constexpr openspace::properties::Property::PropertyInfo OriginInfo = {
        "Origin",
        "Texture Coordinate Origin",
        "The origin of the texture coorinate system."
    };
} // namespace

namespace openspace {

documentation::Documentation RenderableDebugPlane::Documentation() {
    using namespace documentation;
    return {
        "RenderableDebugPlane",
        "debugging_renderable_debugplane",
        {
            {
                TextureInfo.identifier,
                new IntVerifier,
                Optional::Yes,
                TextureInfo.description
            },
            {
                BillboardInfo.identifier,
                new BoolVerifier,
                Optional::Yes,
                BillboardInfo.description
            },
            {
                SizeInfo.identifier,
                new DoubleVerifier,
                Optional::Yes,
                SizeInfo.description
            },
            {
                OriginInfo.identifier,
                new StringInListVerifier(
                    { "LowerLeft", "LowerRight", "UpperLeft", "UpperRight", "Center" }
                ),
                Optional::Yes,
                OriginInfo.description
            }
        }
    };
}


RenderableDebugPlane::RenderableDebugPlane(const ghoul::Dictionary& dictionary)
    : Renderable(dictionary)
    , _texture(TextureInfo, -1, -1, 512)
    , _billboard(BillboardInfo, false)
    , _size(SizeInfo, 10.f, 0.f, 1e25f)
    , _origin(OriginInfo, properties::OptionProperty::DisplayType::Dropdown)
{
    if (dictionary.hasKey(TextureInfo.identifier)) {
        _texture = static_cast<int>(dictionary.value<double>(TextureInfo.identifier));
    }

    if (dictionary.hasKey(SizeInfo.identifier)) {
        _size = static_cast<float>(dictionary.value<double>(SizeInfo.identifier));
    }

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

    _origin.addOptions({
        { LowerLeft, "LowerLeft" },
        { LowerRight, "LowerRight" },
        { UpperLeft, "UpperLeft" },
        { UpperRight, "UpperRight" },
        { Center, "Center" }
    });
    _origin.setValue(Center);

    if (dictionary.hasKey(OriginInfo.identifier)) {
        const std::string origin = dictionary.value<std::string>(OriginInfo.identifier);
        if (origin == "LowerLeft") {
            _origin = LowerLeft;
        }
        else if (origin == "LowerRight") {
            _origin = LowerRight;
        }
        else if (origin == "UpperLeft") {
            _origin = UpperLeft;
        }
        else if (origin == "UpperRight") {
            _origin = UpperRight;
        }
        else if (origin == "Center") {
            _origin = Center;
        }
    }
    else {
        _origin = Center;
    }

    addProperty(_texture);

    addProperty(_billboard);

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

    setBoundingSphere(_size);
}

bool RenderableDebugPlane::isReady() const {
    bool ready = true;
    if (!_shader) {
        ready &= false;
    }
    return ready;
}

void RenderableDebugPlane::initializeGL() {
    glGenVertexArrays(1, &_quad); // generate array
    glGenBuffers(1, &_vertexPositionBuffer); // generate buffer
    createPlane();

    if (!_shader) {
        _shader = global::renderEngine.buildRenderProgram("PlaneProgram",
            absPath("${MODULE_BASE}/shaders/plane_vs.glsl"),
            absPath("${MODULE_BASE}/shaders/plane_fs.glsl")
        );
    }
}

void RenderableDebugPlane::deinitializeGL() {
    glDeleteVertexArrays(1, &_quad);
    _quad = 0;

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

    if (_shader) {
        global::renderEngine.removeRenderProgram(_shader.get());
        _shader = nullptr;
    }
}

void RenderableDebugPlane::render(const RenderData& data, RendererTasks&) {
    glm::mat4 transform = glm::mat4(1.0);
    if (_billboard) {
        transform = glm::inverse(glm::mat4(data.camera.viewRotationMatrix()));
    }

    // Activate shader
    _shader->activate();

    _shader->setUniform("ViewProjection", data.camera.viewProjectionMatrix());
    _shader->setUniform("ModelTransform", transform);
    setPscUniforms(*_shader, data.camera, data.position);

    ghoul::opengl::TextureUnit unit;
    unit.activate();
    glBindTexture(GL_TEXTURE_2D, _texture);
    _shader->setUniform("texture1", unit);

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

    _shader->deactivate();
}

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

    if (_planeIsDirty) {
        createPlane();
    }
}

void RenderableDebugPlane::createPlane() {
    // ============================
    //         GEOMETRY (quad)
    // ============================
    const GLfloat size = _size;

    const GLfloat vertexData[] = {
        //  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(vertexData), vertexData, GL_STATIC_DRAW);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 6, nullptr);
    glEnableVertexAttribArray(1);
    glVertexAttribPointer(
        1,
        2,
        GL_FLOAT,
        GL_FALSE,
        sizeof(GLfloat) * 6,
        reinterpret_cast<void*>(sizeof(GLfloat) * 4)
    );
}

} // namespace openspace