#include <SFML/System.hpp>
#include <SFML/Window.hpp>
#include <SFML/Graphics.hpp>
#include <iostream>

void processEvents(sf::Window *app);
void processInput(sf::Window *app, const sf::Input &input);

void renderCube(sf::Window *app, sf::Clock *clock);
void renderGlScene(sf::Window *app);

int loadResources();

void init();

void update();

GLuint texture_handle;

float xRot = 0.0f;
float yRot = 0.0f;
float zRot = 0.0f;

int main()  {
    sf::Window app(sf::VideoMode(800, 600, 32), "Lesson 6");

    app.UseVerticalSync(false);

    init();

    if (loadResources() == -1)  {
        return EXIT_FAILURE;
    }

    while (app.IsOpened())  {
        update();

        processEvents(&app);

        //renderCube(&app, &clock);
        renderGlScene(&app);

        app.Display() ;
    }

    return EXIT_SUCCESS;
}

int loadResources()  {
    sf::Image img_data;

    // Load Texture
    if (!img_data.LoadFromFile("data/images/crate.jpg"))  {
        std::cout << "Could not load data/images/crate.jpg";

        return -1;
    }

    // Give the texture an id
    glGenTextures(1, &texture_handle);

    // Bind the id to a texture (i.e: associate the id with a texture)
    glBindTexture(GL_TEXTURE_2D, texture_handle);

    //
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, img_data.GetWidth(), img_data.GetHeight(), 0, GL_RGBA, GL_UNSIGNED_BYTE, img_data.GetPixelsPtr());

    //
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    return 0;
}

void update()  {
    xRot += 0.003f;
    yRot += 0.002f;
    zRot += 0.004f;
}

void init()  {
    glClearDepth(1.f);
    glClearColor(0.f, 0.f, 0.f, 0.f);

    // Enable z-buffer and read and write
    glEnable(GL_DEPTH_TEST);
    glDepthMask(GL_TRUE);

    // Setup a perpective projection
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45.f, 1.f, 1.f, 500.f);
}

void processEvents(sf::Window *app)  {
    sf::Event event;

    while (app->GetEvent(event))  {
        if (event.Type == sf::Event::Closed)  {
            app->Close();
        }

        if (event.Type == sf::Event::KeyPressed &&
            event.Key.Code == sf::Key::Escape)  {
            app->Close();
        }
    }
}

void renderGlScene(sf::Window *app)  {
    app->SetActive();

       // Clear color depth buffer
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    // Apply some transformations
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    glTranslatef(0.0f,0.0f,-5.0f);

    glRotatef(xRot,1.0f,0.0f,0.0f);                     // Rotate On The X Axis
    glRotatef(yRot,0.0f,1.0f,0.0f);                     // Rotate On The Y Axis
    glRotatef(zRot,0.0f,0.0f,1.0f);                     // Rotate On The Z Axis

    glBindTexture(GL_TEXTURE_2D, texture_handle);

    glBegin(GL_QUADS);
        // Front Face
        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);  // Bottom Left Of The Texture and Quad
        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);  // Bottom Right Of The Texture and Quad
        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);  // Top Right Of The Texture and Quad
        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);  // Top Left Of The Texture and Quad
        // Back Face
        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);  // Bottom Right Of The Texture and Quad
        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);  // Top Right Of The Texture and Quad
        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);  // Top Left Of The Texture and Quad
        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);  // Bottom Left Of The Texture and Quad
        // Top Face
        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);  // Top Left Of The Texture and Quad
        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f,  1.0f,  1.0f);  // Bottom Left Of The Texture and Quad
        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f,  1.0f,  1.0f);  // Bottom Right Of The Texture and Quad
        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);  // Top Right Of The Texture and Quad
        // Bottom Face
        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);  // Top Right Of The Texture and Quad
        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f);  // Top Left Of The Texture and Quad
        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);  // Bottom Left Of The Texture and Quad
        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);  // Bottom Right Of The Texture and Quad
        // Right face
        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);  // Bottom Right Of The Texture and Quad
        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);  // Top Right Of The Texture and Quad
        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);  // Top Left Of The Texture and Quad
        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);  // Bottom Left Of The Texture and Quad
        // Left Face
        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);  // Bottom Left Of The Texture and Quad
        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);  // Bottom Right Of The Texture and Quad
        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);  // Top Right Of The Texture and Quad
        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);  // Top Left Of The Texture and Quad
    glEnd();
}