#ifdef _WINDOWS
    #include <GL/glew.h>
#endif
#include <SDL.h>
#include <SDL_opengl.h>
#include <SDL_image.h>
#include "ShaderProgram.h"
#include "Matrix.h"

#ifdef _WINDOWS
    #define RESOURCE_FOLDER ""
#else
    #define RESOURCE_FOLDER "NYUCodebase.app/Contents/Resources/"
#endif



GLuint LoadTexture(const char *image_path) {
    SDL_Surface *surface = IMG_Load(image_path);
    GLuint textureID;
    glGenTextures(1, &textureID);
    glBindTexture(GL_TEXTURE_2D, textureID);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, surface->w, surface->h, 0, GL_RGBA,
        GL_UNSIGNED_BYTE, surface->pixels);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    SDL_FreeSurface(surface);
    return textureID;
}


SDL_Window* displayWindow;


int main(int argc, char *argv[])
{
    SDL_Init(SDL_INIT_VIDEO);
    displayWindow = SDL_CreateWindow("My Game", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 360, SDL_WINDOW_OPENGL);
    SDL_GLContext context = SDL_GL_CreateContext(displayWindow);
    SDL_GL_MakeCurrent(displayWindow, context);
    #ifdef _WINDOWS
        glewInit();
    #endif

    glViewport(0, 0, 640, 360);


    ShaderProgram program(RESOURCE_FOLDER"vertex_textured.glsl", RESOURCE_FOLDER"fragment_textured.glsl");

    GLuint emojiTexture = LoadTexture("emoji.png");
    Matrix projectionMatrix;
    Matrix modelMatrix;
    Matrix viewMatrix;


    projectionMatrix.setOrthoProjection(-3.55, 3.55, -2.0f, 2.0f, -1.0f, 1.0f);

    glUseProgram(program.programID);

    SDL_Event event;
    bool done = false;
    while (!done) {
        while (SDL_PollEvent(&event)) {
            if (event.type == SDL_QUIT || event.type == SDL_WINDOWEVENT_CLOSE) {
                done = true;
            }
        }

        program.setModelMatrix(modelMatrix);
        program.setProjectionMatrix(projectionMatrix);
        program.setViewMatrix(viewMatrix);


        glBindTexture(GL_TEXTURE_2D, emojiTexture);
        float vertices[] = { -0.5, -0.5, 0.5, -0.5, 0.5, 0.5, -0.5, -0.5, 0.5, 0.5, -0.5, 0.5 };
        glVertexAttribPointer(program.positionAttribute, 2, GL_FLOAT, false, 0, vertices);
        glEnableVertexAttribArray(program.positionAttribute);
        float texCoords[] = { 0.0, 1.0, 1.0, 1.0, 1.0, 0.0, 0.0, 1.0, 1.0, 0.0, 0.0, 0.0 };
        glVertexAttribPointer(program.texCoordAttribute, 2, GL_FLOAT, false, 0, texCoords);
        glEnableVertexAttribArray(program.texCoordAttribute);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        glDisableVertexAttribArray(program.positionAttribute);
        glDisableVertexAttribArray(program.texCoordAttribute);

        glClear(GL_COLOR_BUFFER_BIT);
        SDL_GL_SwapWindow(displayWindow);
    }

    SDL_Quit();
    return 0;
}