#define _POSIX_C_SOURCE 200112L
#include <wayland-client.h>
#include "xdg-shell-client-protocol.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

struct wl_display *display = NULL;
struct wl_registry *registry = NULL;
struct wl_compositor *compositor = NULL;
struct xdg_wm_base *wm_base = NULL;
struct wl_surface *surface = NULL;
struct xdg_surface *xdg_surface = NULL;
struct xdg_toplevel *xdg_toplevel = NULL;

static void xdg_wm_base_ping(void *data, struct xdg_wm_base *xdg_wm_base, uint32_t serial)
{
	xdg_wm_base_pong(xdg_wm_base, serial);
}

static const struct xdg_wm_base_listener wm_base_listener = {
	.ping = xdg_wm_base_ping,
};

static void xdg_surface_configure(void *data, struct xdg_surface *xdg_surface, uint32_t serial)
{
	xdg_surface_ack_configure(xdg_surface, serial);
}

static const struct xdg_surface_listener xdg_surface_listener = {
	.configure = xdg_surface_configure,
};

static void xdg_toplevel_configure(void *data, struct xdg_toplevel *xdg_toplevel,
	int32_t width, int32_t height, struct wl_array *states)
{
	/* just exist */
}

static void xdg_toplevel_close(void *data, struct xdg_toplevel *xdg_toplevel)
{
	printf("close requested\n");
	exit(0);
}

static const struct xdg_toplevel_listener xdg_toplevel_listener = {
	.configure = xdg_toplevel_configure,
	.close = xdg_toplevel_close,
};

static void registry_handle_global(void *data, struct wl_registry *reg, uint32_t id,
	const char *interface, uint32_t version)
{
	if (strcmp(interface, wl_compositor_interface.name) == 0) {
		compositor = wl_registry_bind(reg, id, &wl_compositor_interface, 4);
	} else if (strcmp(interface, xdg_wm_base_interface.name) == 0) {
		wm_base = wl_registry_bind(reg, id, &xdg_wm_base_interface, 1);
		xdg_wm_base_add_listener(wm_base, &wm_base_listener, NULL);
	}
}

static void registry_handle_global_remove(void *data, struct wl_registry *reg, uint32_t id)
{
	/* ignore */
}

static const struct wl_registry_listener registry_listener = {
	.global = registry_handle_global,
	.global_remove = registry_handle_global_remove,
};

int main(void)
{
	display = wl_display_connect(NULL);
	if (!display) {
		fprintf(stderr, "can't connect\n");
		return 1;
	}

	registry = wl_display_get_registry(display);
	wl_registry_add_listener(registry, &registry_listener, NULL);
	wl_display_roundtrip(display);

	if (!compositor || !wm_base) {
		fprintf(stderr, "missing compositor or xdg_wm_base\n");
		return 1;
	}

	surface = wl_compositor_create_surface(compositor);
	xdg_surface = xdg_wm_base_get_xdg_surface(wm_base, surface);
	xdg_surface_add_listener(xdg_surface, &xdg_surface_listener, NULL);

	xdg_toplevel = xdg_surface_get_toplevel(xdg_surface);
	xdg_toplevel_add_listener(xdg_toplevel, &xdg_toplevel_listener, NULL);
	xdg_toplevel_set_title(xdg_toplevel, "wayland window");

	wl_surface_commit(surface);
	wl_display_roundtrip(display);

	printf("window open, running...\n");

	while (wl_display_dispatch(display) != -1) {
		/* events handled by callbacks */
	}

	wl_display_disconnect(display);
	return 0;
}