#include <stdio.h>
#include <stdlib.h>

#include "window.hpp"

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

#define MIN_WIDTH 854
#define MIN_HEIGHT 480

void framebuffer_size_callback(GLFWwindow *window, int width, int height) {
    glViewport(0, 0, width, height);
}

GLFWwindow* createWindow(int samples) {
    GLFWwindow *window;

    // Initialise GLFW
    if (!glfwInit()) {
        fprintf(stderr, "Failed to initialize GLFW\n");
        getchar();
        return NULL;
    }

    glfwWindowHint(GLFW_SAMPLES, samples);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // To make MacOS happy; should not be needed
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    glfwWindowHint(GLFW_RESIZABLE, false); //FIXME: Dev-only: Force floating on i3

    window = glfwCreateWindow(DEFAULT_WIDTH, DEFAULT_HEIGHT, "Univerxel", NULL, NULL);
    if (window == NULL) {
        fprintf(stderr, "Failed to open GLFW window.\n");
        getchar();
        glfwTerminate();
        return NULL;
    }
    glfwMakeContextCurrent(window);

    // Initialize GLEW
    glewExperimental = true; // Needed for core profile
    if (glewInit() != GLEW_OK) {
        fprintf(stderr, "Failed to initialize GLEW\n");
        getchar();
        glfwTerminate();
        return NULL;
    }

    // Ensure we can capture the escape key being pressed below
    glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);
    // Hide the mouse and enable unlimited mouvement
    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);

    // Set the mouse at the center of the screen
    glfwPollEvents();
    glfwSetCursorPos(window, DEFAULT_WIDTH / 2, DEFAULT_HEIGHT / 2);

    // Force aspect ratio
    glfwSetWindowSizeLimits(window, MIN_WIDTH, MIN_HEIGHT, GLFW_DONT_CARE, GLFW_DONT_CARE);
    glfwSetWindowAspectRatio(window, RATIO_WIDTH, RATIO_HEIGHT);

    // Handle resize
    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

    glfwSetWindowTitle(window, "Univerxel");
    glfwSetWindowAttrib(window, GLFW_RESIZABLE, true);

    // Enable depth test
    glEnable(GL_DEPTH_TEST);
    // Accept fragment if it closer to the camera than the former one
    glDepthFunc(GL_LEQUAL);

    // Cull triangles which normal is not towards the camera
    glEnable(GL_CULL_FACE);
    glCullFace(GL_BACK);

    GLint smp;
    glGetIntegerv(GL_SAMPLES, &smp);
    if(smp > 0) {
        glEnable(GL_MULTISAMPLE);
    }

    return window;
}