#pragma once
#include <GL/glew.h>
#include "shaders.hpp"
#include <glm/glm.hpp>
#include <chrono>
#include "glm/gtc/matrix_transform.hpp"

using namespace std::chrono;

/**
 * Bind this fonction with the following for debugging:
 * 	glEnable              ( GL_DEBUG_OUTPUT );
 *	glDebugMessageCallback( MessageCallback, 0 );
 * @param source
 * @param type
 * @param id
 * @param severity
 * @param length
 * @param message
 * @param userParam
 */
void GLAPIENTRY MessageCallback( GLenum source,
                 GLenum type,
                 GLuint id,
                 GLenum severity,
                 GLsizei length,
                 const GLchar* message,
                 const void* userParam);

/**
 * Main renderer class
 */
class Renderer {
private:
	GLuint VAO;
	GLuint RayMarchingShader;
	GLuint UProjection;
	GLuint UResolution;
	GLuint UModel;
	GLuint UTime;
	glm::mat4 MProjection;
	glm::mat4 MModel;
	short Width,Height;
	steady_clock::time_point ClockStart;
	steady_clock::time_point ClockCurrent;
	/// @brief Current loaded shader name
	std::string CurrentShader;

	/**
	 * Compile send CurrentShader to the graphics card
	 */
	void LoadShader();

public:
	Renderer(short width,short height,std::string shader_name);
	~Renderer();
	/**
	 * Draw current shader into the screen
	 */
	void Render();
	/**
	 * Change current OpenGL viewport.
	 * @param with
	 * @param height
	 */
	void AjustViewport(short with,short height);
	/**
	 * Compile and load another shader
	 * @param name The name of the new shader
	 */
	void ChangeShader(std::string name);
	/**
	 * Refresh CurrentShader code (recompile it etc..)
	 */
	void RefreshShader();
};