#ifndef WRAPPER_H
#define WRAPPER_H

#include <GL/glew.h>
#include <GLFW/glfw3.h>

#include <iostream>

using namespace std;

class IClient
{
public:
    virtual void tick() = 0;
    virtual void renderTick(float lag) = 0;
    virtual void onKeyEvent(int key, int scancode, int action, int mods) = 0;
    virtual void onMouseClick(int button, int action, int mods) = 0;
};

class DummyClient : public IClient
{
public:
    static DummyClient dummy;
    
    void tick() override { cout << "Dummy tick" << endl; };
    void renderTick(float lag) override { cout << "Dummy renderTick" << endl; };
    void onKeyEvent(int key, int scancode, int action, int mods) override { cout << "Dummy onKeyEvent" << endl; };
    void onMouseClick(int button, int action, int mods) override { cout << "Dummy onMouseClick" << endl; };
private:
    DummyClient() {};
};

class Engine
{
public:
    static bool init(int width, int height, const char* name);
    static void start(IClient& client);
    static void stop();
    
    void printError();
    
    static int getScale();
    static int getWidth();
    static int getHeight();
    
    static GLint getUniformLocation(const GLchar* name);
    static void setMatrix(GLint location, const GLfloat* m);
    static void setInt(GLint location, GLint i);
    static void setFloat(GLint location, GLfloat f1, GLfloat f2, GLfloat f3, GLfloat f4);
private:
    static const uint64_t NANOS_PER_TICK = 50000000;
    static const int MAX_TICKS_PER_FRAME = 5;
    
    static GLchar* readFile(const char* name);
    static bool checkShaderErrors(const char* name, GLuint shader);
    static GLuint compileProgram(GLuint& vShader, GLuint& fShader, const GLchar* vertex, const GLchar* fragment);
    static GLuint createProgram(GLuint& vShader, GLuint& fShader);
    
    static void onKeyEvent(GLFWwindow* w, int key, int scancode, int action, int mods);
    static void onMouseClick(GLFWwindow* w, int button, int action, int mods);
    static void onWindowResize(GLFWwindow* w, int width, int height);
    
    static void updateScale();
    
    static IClient* client;    
    static GLFWwindow* window;   
    static GLuint vShader;
    static GLuint fShader;
    static GLuint program;
    static int scale;
    static int width;
    static int height;
};

#endif