// GLEW
#define GLEW_STATIC
#include <GL/glew.h>

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

// GL includes
#include "Shader.h"

// Properties
GLuint screenWidth = 800, screenHeight = 600;

// The MAIN function, from here we start our application and run our Game loop
int main()
{
    // Init GLFW
    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);

    GLFWwindow* window = glfwCreateWindow(screenWidth, screenHeight, "LearnOpenGL", nullptr, nullptr); // Windowed
    glfwMakeContextCurrent(window);

    // Options
    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);	

    // Initialize GLEW to setup the OpenGL Function pointers
    glewExperimental = GL_TRUE;
    glewInit();

    // Define the viewport dimensions
    glViewport(0, 0, screenWidth, screenHeight);

    // Setup and compile our shaders
    Shader shader("shaders/geometry.vs", "shaders/geometry.frag", "shaders/geometry.gs");

    // Vertex data
    GLfloat points[] = {
        -0.5f,  0.5f, 1.0f, 0.0f, 0.0f, // Top-left
         0.5f,  0.5f, 0.0f, 1.0f, 0.0f, // Top-right
         0.5f, -0.5f, 0.0f, 0.0f, 1.0f, // Bottom-right
        -0.5f, -0.5f, 1.0f, 1.0f, 0.0f  // Bottom-left
    };
    GLuint VBO, VAO;
    glGenBuffers(1, &VBO);
    glGenVertexArrays(1, &VAO);
    glBindVertexArray(VAO);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(points), &points, GL_STATIC_DRAW);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), 0);
    glEnableVertexAttribArray(1);
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)(2 * sizeof(GLfloat)));
    glBindVertexArray(0);

    //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

    // Game loop
    while(!glfwWindowShouldClose(window))
    {
        // Check and call events
        glfwPollEvents();

        // Clear buffers
        glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        // Draw points
        shader.Use();
        glBindVertexArray(VAO);
        glDrawArrays(GL_POINTS, 0, 4);
        glBindVertexArray(0);
        
        // Swap the buffers
        glfwSwapBuffers(window);
    }

    glfwTerminate();
    return 0;
}