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

#include "voxel.h"
#include "window.h"

Window window;
double delta_time;

static void key_callback(GLFWwindow *, int key, int, int action, int)
{
	switch (action) {
	case GLFW_PRESS:
		window.key_down[key] = true;
		window.key_pressed[key] = true;
		break;
	case GLFW_RELEASE:
		window.key_down[key] = false;
		break;
	}
}

static void mouse_move_callback(GLFWwindow *, double xpos, double ypos)
{
	window.mouse_x_last = window.mouse_x;
	window.moues_y_last = window.mouse_y;
	window.mouse_x = xpos;
	window.mouse_y = ypos;
}

static void mouse_button_callback(GLFWwindow *, int button, int action, int)
{
	switch (action) {
	case GLFW_PRESS:
		window.btn_down[button] = true;
		window.btn_pressed[button] = true;
		break;
	case GLFW_RELEASE:
		window.btn_down[button] = false;
		break;
	}
}

static void framebuffer_callback(GLFWwindow *, int width, int height)
{
	window.width = width;
	window.height = height;
	glViewport(0, 0, width, height);
}

int window_init(void)
{
	if (glfwInit() == GLFW_FALSE) {
		ERROR("GLFW failed to initalize");
		return 1;
	}

	memset(&window, 0, sizeof(Window));
	delta_time = 0;

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

	window.monitor = glfwGetPrimaryMonitor();
	window.window = glfwCreateWindow(WINDOW_WIDTH, WINDOW_HEIGHT, WINDOW_TITLE,
					 window.monitor, NULL);
	if (window.window == NULL) {
		ERROR("failed to create window");
		return 1;
	}

	glfwMakeContextCurrent(window.window);
	glfwSwapInterval(0);

	glewExperimental = GL_TRUE;
	if (glewInit() != GLEW_OK) {
		ERROR("GLEW failed to initalize");
		return 1;
	}

	glfwSetKeyCallback(window.window, key_callback);
	glfwSetCursorPosCallback(window.window, mouse_move_callback);
	glfwSetMouseButtonCallback(window.window, mouse_button_callback);
	glfwSetFramebufferSizeCallback(window.window, framebuffer_callback);

	return 0;
}

bool window_closed(void)
{
	return glfwWindowShouldClose(window.window) == GLFW_TRUE;
}

void window_update(void)
{
	// reset "pressed"
	memset(&window.key_pressed, 0, sizeof(window.key_pressed));
	memset(&window.btn_pressed, 0, sizeof(window.btn_pressed));

	// update delta time
	double time = glfwGetTime();
	delta_time = time - window.last_time;
	window.last_time = time;

	// check for errors
	GLenum error;
	while ((error = glGetError()) != GL_NO_ERROR)
		ERROR("OpenGL error: %d", error);

	glfwPollEvents();
}

void window_swap(void)
{
	glfwSwapBuffers(window.window);
}

void window_close(void)
{
	glfwDestroyWindow(window.window);
	glfwTerminate();
}

int window_grab_cursor(void);
int window_release_cursor(void);

bool key_down(int key)
{
	return window.key_down[key];
}

bool key_pressed(int key)
{
	return window.key_pressed[key];
}

bool btn_down(int btn)
{
	return window.btn_down[btn];
}

bool btn_pressed(int btn)
{
	return window.btn_pressed[btn];
}