#ifndef POSTEFFECTMODULE_H
#define POSTEFFECTMODULE_H

#include "opengl.h"
#include <glm/mat4x4.hpp>
#include <glm/vec3.hpp>
#include "module.h"
#include <string>

class Shader;
class FrameBuffer;
class Texture;
class TextureBlur;
class ShaderSource;
class TextureRedux;

class PostEffectModule : public Module
{
    // framebuffers
    enum
    {
        INPUT_FBO,
        LUMINANCE_FBO,
        BLOOM_FBO,
        NB_FBO
    };
    FrameBuffer* frameBuffers;
    const FrameBuffer* outputFBO;

    // shaders
    enum
    {
        LUMINANCE_SHADER,
        BLOOM_SHADER,
        HDR_SHADER,
        REDUX_SHADER,
        NB_SHADERS
    };

    static const std::string vertSource;
    Shader* shaders[NB_SHADERS];

    // dimensions
    int width;
    int height;

    // geometry (one triangle)
    GLuint vao;
    GLuint vbo;
    static const GLfloat vertices[];

    // post processing pipeline
    void luminanceStep();
    void bloomStep();
    void hdrStep();
    TextureBlur* blur;
    ShaderSource* blurSource;
    TextureRedux* redux;

    // arguments
    float bloom_threshold;

public:
    PostEffectModule(int width, int height);
    ~PostEffectModule();

    virtual void renderGL(Camera* myCamera, Scene* scene);
    virtual void resize(int w, int h);

    /**
     * @brief setShaders must be called to set the 5 required fragment shaders
     */
    void setShaders(const std::string &luminanceSource,
                    const std::string &bloomSource,
                    const std::string &hdrSource,
                    const std::string &blurSource,
                    const std::string &reduxSource);

    FrameBuffer* getInputFBO() {return frameBuffers;}

    void setRenderTarget(FrameBuffer* renderTarget) {outputFBO = renderTarget;}

    void setBloomThreshold(float threshold) {bloom_threshold = threshold;}

    glm::vec3 getObjectInfo(int x, int y);
};

#endif // POSTEFFECTMODULE_H