#include <GLFW/glfw3.h>
#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>
#include <stdio.h>
#include <iostream>

GLuint loadBMP_custom(const char * imagepath);

void EnableTransparency()
{
        glEnable(GL_BLEND);
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}

GLuint LoadTexture(char *filename,int *textw,int *texth) {
        SDL_Surface *surface;
        GLuint textureid;
        int mode;
        surface = IMG_Load(filename);
        // Or if you don't use SDL_image you can use SDL_LoadBMP here instead:
        // surface = SDL_LoadBMP(filename);

        // could not load filename
        if (!surface) {
                return 0;
        }

        // work out what format to tell glTexImage2D to use...
        if (surface->format->BytesPerPixel == 3) { // RGB 24bit
                mode = GL_RGB;

        } else if (surface->format->BytesPerPixel == 4) { // RGBA 32bit
                mode = GL_RGBA;
        } else {
                SDL_FreeSurface(surface);
                return 0;
        }

        *textw=surface->w;
        *texth=surface->h;
        // create one texture name
        glGenTextures(1, &textureid);
        // tell opengl to use the generated texture name
        glBindTexture(GL_TEXTURE_2D, textureid);
        // this reads from the sdl surface and puts it into an opengl texture
        glTexImage2D(GL_TEXTURE_2D, 0, mode, surface->w, surface->h, 0, mode, GL_UNSIGNED_BYTE, surface->pixels);
        // these affect how this texture is drawn later on...glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        // clean up
        SDL_FreeSurface(surface);
        return textureid;

}

void DrawTexture(int x, int y, GLuint textureid,int textw,int texth) {
        //printf("x: %d\ty: %d\tw: %d\th: %d\n", x, y, textw, texth);
        //int textw,texth;
        // tell opengl to use the generated texture name
        glBindTexture(GL_TEXTURE_2D, textureid);
        glEnable(GL_TEXTURE_2D);
        // make a rectangle
        glBegin(GL_QUADS);
            glTexCoord2d(0.0,0.0); glVertex2f(-1, -1);
            glTexCoord2d(1.0,0.0); glVertex2f(1, -1);
            glTexCoord2d(1.0,1.0); glVertex2f(1, 1);
            glTexCoord2d(0.0,1.0); glVertex2f(-1, 1);
        glEnd();
        glDisable(GL_TEXTURE_2D );
}

int main(int argc, char* args[]) {
    GLFWwindow* window;
    GLuint myglu;
    int textw, texth;


    /* Initialize the library */
    /* GLFW */
    if (!glfwInit())
        return -1;
    /* SDL */
    if (SDL_Init(SDL_INIT_VIDEO) < 0)
        printf("SDL Error");
    /* Create a windowed mode window and its OpenGL context */
    window = glfwCreateWindow(640, 480, "Hello World", NULL, NULL);
    if (!window) {
        glfwTerminate();
        return -1;
    }
    /* Make the window's context current */
    glfwMakeContextCurrent(window);
    // INIT

    myglu=LoadTexture("../img/tests/stones.bmp",&textw,&texth);

    // INIT END
    /* Loop until the user closes the window */
    while (!glfwWindowShouldClose(window)) {
        /* Render here */
        glClear(GL_COLOR_BUFFER_BIT);
        // RENDER
        DrawTexture(50,50,myglu,textw,texth);


        // RENDER END
        /* Swap front and back buffers */
        glfwSwapBuffers(window);
        /* Poll for and process events */
        glfwPollEvents();
    }
    glfwTerminate();
    return 0;
}