/* Copyright (c) 2025 Quinn
 * Licensed under the MIT Licence. See LICENSE for details */
#include "window.h"

#include <GLFW/glfw3.h>
#include <assert.h>
#include <glad/gl.h>

#include "../types.h"
#include "../util/error.h"
#include "input.h"
#include "render.h"

static struct GLFWwindow *win = NULL;

/* Initialises the GLFW window with some defaults,
 * then proceed to activate OpenGL on it. */
int window_init(void)
{
	// initialise the window
#ifndef NDEBUG
	glfwWindowHint(GLFW_OPENGL_DEBUG_CONTEXT, GLFW_TRUE);
#endif
	glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
	glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, 1);
	glfwWindowHint(GLFW_RED_BITS, 8);
	glfwWindowHint(GLFW_GREEN_BITS, 8);
	glfwWindowHint(GLFW_BLUE_BITS, 8);
	glfwWindowHint(GLFW_ALPHA_BITS, 0);
	/* NOTE: on my system; x86_64, GTX 1650 580.82.09-2, X11, i3, this causes one direct,
	 * 2 indirect memory leaks. This is not my fault, and can safely be ignored. */
	win = glfwCreateWindow(640, 480, "MCA-Selector lite", NULL, NULL);
	if (!win)
		return 1;

	glfwMakeContextCurrent(win);
	if (!gladLoadGL(glfwGetProcAddress))
		return 1;
	/* wait 1 screen update for a redraw a.k.a. "vsync".
	(not really applicable in this case, but eh) */
	glfwSwapInterval(1);

	glfwSetKeyCallback(win, input_callback);

	debug("version info:\n"
	      "\tvendor:       %s\n"
	      "\trenderer:     %s\n"
	      "\tversion:      %s\n"
	      "\tshading lang: %s\n",
		glGetString(GL_VENDOR), glGetString(GL_RENDERER), glGetString(GL_VERSION),
		glGetString(GL_SHADING_LANGUAGE_VERSION));
	return 0;
}

void window_loop(void)
{
	assert(win);
	render_init();
	while (!glfwWindowShouldClose(win)) {
		glfwWaitEvents();

		render_update(win);
		glfwSwapBuffers(win);
		glfwPollEvents();
	}
}

void window_close(void)
{
	assert(win);
	glfwSetWindowShouldClose(win, 1);
}

void window_free(void)
{
	if (!win) {
		debug("window has already been freed.");
		return;
	}

	glfwDestroyWindow(win);
	render_free();
	win = NULL;
}