#include "main.h"
#include <GLFW/glfw3.h>
#include <stdio.h>
#include <time.h>

void __window_callback_input(GLFWwindow *, int, int);
void __mouse_callback_input(GLFWwindow *, int, int, int);
void __scroll_callback_input(GLFWwindow *, double, double);
void __key_callback_input(GLFWwindow *, int, int, int, int);

window_t init_window(unsigned int w, unsigned int h, const char *name);

/*
	Limitamos los FPS, contando el tiempo en el que
	se ejecuta el main loop, y esperando el tiempo restante
	para lograr los fps deseados.
*/

static void __limit_fps_window(int max_fps)
{
	static double previous_time = 0.0;
	double current_time;
	double frame_time;
	double elapsed_time;

	current_time = glfwGetTime();
	frame_time = 1.0 / max_fps;
	elapsed_time = current_time - previous_time;

	if (elapsed_time < frame_time)
	{
		struct timespec sleep_time;
		sleep_time.tv_sec = 0;
		sleep_time.tv_nsec = (long)((frame_time - elapsed_time) * 1e9);
		nanosleep(&sleep_time, NULL);

		current_time = glfwGetTime();
	}

	previous_time = current_time;
}

window_t init_window(unsigned int width, unsigned int height, const char *title)
{
	window_t window;

	if (!glfwInit())
		return NULL;

	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

	window = (window_t)glfwCreateWindow(width, height, title, NULL, NULL);
	if (!(window))
	{
		glfwTerminate();
		return NULL;
	}

	glfwMakeContextCurrent((GLFWwindow *)(window));

	glfwSetWindowSizeCallback((GLFWwindow *)window, __window_callback_input);
	glfwSetMouseButtonCallback((GLFWwindow *)window, __mouse_callback_input);
	glfwSetScrollCallback((GLFWwindow *)window, __scroll_callback_input);
	glfwSetKeyCallback((GLFWwindow *)window, __key_callback_input);

	__window_callback_input((GLFWwindow *)window, width, height);

	return window;
}

void use_window(window_t window) { glfwMakeContextCurrent((void *)window); }

extern int window_width, window_height;

int is_open_window(window_t window)
{
	/* Restore window proportions if Nuklear breaks it */
	__window_callback_input((GLFWwindow *)window, window_width, window_height);

	glfwSwapBuffers((void *)window);
	glfwPollEvents();

	__limit_fps_window(60);
	return !glfwWindowShouldClose((void *)window);
}

void close_window(window_t window)
{
	glfwDestroyWindow((GLFWwindow *)window);
	glfwTerminate();
}