#include <bits/time.h>
#include <sys/mman.h>
#include <sys/timerfd.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <wayland-client-protocol.h>
#include <xkbcommon/xkbcommon.h>
#include <time.h>
#include <poll.h>
#include <errno.h>

#include "wayland.h"
#include "drw.h"
#include "xdg-shell-client-protocol.h"

/* macro definitions */
#define match_then_bind(obj, inter, ver) \
	if (strcmp(interface, inter.name) == 0) { \
		obj = wl_registry_bind(registry, name, &inter, ver);

#define end_match }
#define or_match } else

/* struct definitions */
typedef struct {
	unsigned width;
	unsigned height;
	struct {
		struct wl_surface *wl;
		struct xdg_surface *xdg;
		struct xdg_toplevel *toplevel;
	} surface;
	Canvas *canvas;
	Font *font;
} Window;


static void setup();
static void buffer_release(void *data, struct wl_buffer *buffer);
static void draw_frame();
static void surface_configure(void *data, struct xdg_surface *surface, uint32_t serial);
static void toplevel_configure(void *data, struct xdg_toplevel *toplevel, int32_t width, int32_t height, struct wl_array *clients);
static void toplevel_close(void *data, struct xdg_toplevel *toplevel);
static void wm_base_ping(void *data, struct xdg_wm_base *wm_base, uint32_t serial);
static void registry_global(void *data, struct wl_registry *registry, uint32_t name, const char *interface, uint32_t version);
static void registry_global_remove(void *data, struct wl_registry *registry, uint32_t name);
static void seat_capabilities(void *dat, struct wl_seat *seat, uint32_t capabilities);
static void keyboard_keymap(void *data, struct wl_keyboard *keyboard, uint32_t format, int32_t fd, uint32_t size);
static void keyboard_key(void *data, struct wl_keyboard *keyboard, uint32_t serial, uint32_t time, uint32_t key, uint32_t client);
static void keyboard_modifiers(void *data, struct wl_keyboard *keyboard, uint32_t serial, uint32_t depressed, uint32_t latched, uint32_t locked, uint32_t group);
static void keyboard_repeat_info(void *data, struct wl_keyboard *keyboard, int32_t rate, int32_t delay);
static void handle_keyboard_event();
static void pointer_enter(void *data, struct wl_pointer *pointer, uint32_t serial, struct wl_surface *surface, wl_fixed_t x, wl_fixed_t y);
static void pointer_leave(void *data, struct wl_pointer *pointer, uint32_t serial, struct wl_surface *surface);
static void pointer_motion(void *data, struct wl_pointer *pointer, uint32_t time, wl_fixed_t x, wl_fixed_t y);
static void pointer_button(void *data, struct wl_pointer *pointer, uint32_t serial, uint32_t time, uint32_t button, uint32_t state);
static void pointer_axis(void *data, struct wl_pointer *pointer, uint32_t time, uint32_t axis, wl_fixed_t value);
static void dummy() {}


/* global variables */
static const struct wl_registry_listener registry_listener = {
	.global = registry_global,
	.global_remove = registry_global_remove,
};

static const struct wl_buffer_listener buffer_listener = {
	.release = buffer_release,
};

static const struct xdg_surface_listener surface_listener = {
	.configure = surface_configure,
};

static const struct xdg_toplevel_listener toplevel_listener = {
	.configure = toplevel_configure,
	.close = toplevel_close,
	.configure_bounds = dummy,
	.wm_capabilities = dummy
};

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

static const struct wl_seat_listener seat_listener = {
	.capabilities = seat_capabilities,
	.name = dummy
};

static const struct wl_keyboard_listener keyboard_listener = {
	.keymap = keyboard_keymap,
	.key = keyboard_key,
	.modifiers = keyboard_modifiers,
	.repeat_info = keyboard_repeat_info,
	.enter = dummy,
	.leave = dummy,
};

const struct wl_pointer_listener pointer_listener = {
	.enter = pointer_enter,
	.leave = pointer_leave,
	.motion = pointer_motion,
	.button = pointer_button,
	.axis = pointer_axis,
	.axis_discrete = dummy,
	.axis_source = dummy,
	.axis_stop = dummy,
	.axis_value120 = dummy,
	.frame = dummy,
};


Client client = { 0 };
Window win = { 0 };
int running = 1;

#include "config.h"

/* function implementation */
void
buffer_release(void *data, struct wl_buffer *buffer)
{
	wl_buffer_destroy(buffer);
}


void
draw_frame()
{
	draw_rect(win.canvas, 0, 0, win.width, win.height, 0xff00ff00);
}


void
surface_configure(void *data, struct xdg_surface *surface, uint32_t serial)
{
	xdg_surface_ack_configure(surface, serial);

	fprintf(stderr, "configure\n");

	if (win.canvas != 0) {
		free_drw(win.canvas);
	}
	win.canvas = create_drw(client.shm, win.width, win.height);

	draw_frame();
	wl_surface_attach(win.surface.wl, win.canvas->buffer, 0, 0);
	wl_surface_damage_buffer(win.surface.wl, 0, 0, win.width, win.height);
	wl_surface_commit(win.surface.wl);
}


void
toplevel_configure(void *data, struct xdg_toplevel *toplevel, int32_t width, int32_t height, struct wl_array *clients)
{
	if (width == 0 || height == 0) {
		win.width = 800;
		win.height = 600;
	} else {
		win.width = width;
		win.height = height;
	}
}


void
toplevel_close(void *data, struct xdg_toplevel *toplevel)
{
	running = 0;
}


void
wm_base_ping(void *data, struct xdg_wm_base *wm_base, uint32_t serial)
{
	xdg_wm_base_pong(wm_base, serial);
}


void
registry_global(void *data, struct wl_registry *registry, uint32_t name, const char *interface, uint32_t version)
{
	match_then_bind(client.shm, wl_shm_interface, 1)
	or_match match_then_bind(client.compositor, wl_compositor_interface, 4)
	or_match match_then_bind(client.wm_base, xdg_wm_base_interface, 1)
	or_match match_then_bind(client.seat, wl_seat_interface, 7)
		wl_seat_add_listener(client.seat, &seat_listener, &client);
	end_match
}


void
registry_global_remove(void *data, struct wl_registry *registry, uint32_t name)
{
	/* TODO: Check if this is necessary */
}


void
seat_capabilities(void *data, struct wl_seat *seat, uint32_t capabilities)
{
	int has_keyboard = capabilities & WL_SEAT_CAPABILITY_KEYBOARD;

	if (has_keyboard && client.kb.keyboard == 0) {
		client.kb.keyboard = wl_seat_get_keyboard(client.seat);
		wl_keyboard_add_listener(client.kb.keyboard, &keyboard_listener, &client);
	} else {
		wl_keyboard_release(client.kb.keyboard);
		client.kb.keyboard = 0;
	}
}


void
keyboard_keymap(void *data, struct wl_keyboard *keyboard, uint32_t format, int32_t fd, uint32_t size)
{
	char *key_shm;
	struct xkb_keymap *keymap;
	struct xkb_state *state;

	if (format != WL_KEYBOARD_KEYMAP_FORMAT_XKB_V1)
		return;

	key_shm = mmap(0, size, PROT_READ, MAP_SHARED, fd, 0);

	if (key_shm == MAP_FAILED)
		return;

	keymap = xkb_keymap_new_from_string(client.kb.context, key_shm,
	                                    XKB_KEYMAP_FORMAT_TEXT_V1,
	                                    XKB_KEYMAP_COMPILE_NO_FLAGS
	);

	munmap(key_shm, size);
	close(fd);
	
	state = xkb_state_new(keymap);
	xkb_keymap_unref(client.kb.keymap);
	xkb_state_unref(client.kb.state);

	client.kb.state = state;
	client.kb.keymap = keymap;
}


void
keyboard_key(void *data, struct wl_keyboard *keyboard, uint32_t serial, uint32_t time, uint32_t key, uint32_t state)
{
	struct itimerspec spec = { 0 };
	uint32_t keycode = key + 8;

	client.kb.event.sym = xkb_state_key_get_one_sym(client.kb.state, keycode);
	client.kb.event.state = state;

	handle_keyboard_event();

	if (client.kb.event.state == WL_KEYBOARD_KEY_STATE_PRESSED && client.kb.repeat.period >= 0) {
		spec.it_value.tv_sec = client.kb.repeat.delay / 1000;
		spec.it_value.tv_nsec = (client.kb.repeat.delay % 1000) * 1000000;
		timerfd_settime(client.kb.repeat.timer, 0, &spec, 0);
	} else if (client.kb.event.state == WL_KEYBOARD_KEY_STATE_RELEASED) {
		timerfd_settime(client.kb.repeat.timer, 0, &spec, 0);
	}
}


void
keyboard_modifiers(void *data, struct wl_keyboard *keybaord, uint32_t serial, uint32_t depressed, uint32_t latched, uint32_t locked, uint32_t group)
{
	xkb_state_update_mask(client.kb.state, depressed, latched, locked, 0, 0, group);
	
	client.kb.event.mods.alt = xkb_state_mod_name_is_active(
	    client.kb.state,
	    XKB_MOD_NAME_ALT,
	    XKB_STATE_MODS_DEPRESSED | XKB_STATE_MODS_LATCHED
	);
	client.kb.event.mods.ctrl = xkb_state_mod_name_is_active(
	    client.kb.state,
	    XKB_MOD_NAME_CTRL,
	    XKB_STATE_MODS_DEPRESSED | XKB_STATE_MODS_LATCHED
	);
	client.kb.event.mods.shift = xkb_state_mod_name_is_active(
	    client.kb.state,
	    XKB_MOD_NAME_SHIFT,
	    XKB_STATE_MODS_DEPRESSED | XKB_STATE_MODS_LATCHED
	);
}


void
keyboard_repeat_info(void *data, struct wl_keyboard *keyboard, int32_t rate, int32_t delay)
{
	client.kb.repeat.delay = delay;

	if (rate > 0)
		client.kb.repeat.period = 1000 / rate;
	else
		client.kb.repeat.period = -1;
}


void
handle_keyboard_event()
{
	char buf[8];

	if (client.kb.event.state == WL_KEYBOARD_KEY_STATE_PRESSED) {
		if (xkb_keysym_to_utf8(client.kb.event.sym, buf, sizeof(buf))) {
			fprintf(stderr, "keypress: %s\n", buf);
		}
	}
}


void
pointer_enter(void *data, struct wl_pointer *pointer, uint32_t serial, struct wl_surface *surface, wl_fixed_t x, wl_fixed_t y)
{
	fprintf(stderr, "pointer enter: (%i, %i)\n", x, y);
}


void
pointer_leave(void *data, struct wl_pointer *pointer, uint32_t serial, struct wl_surface *surface)
{
	fprintf(stderr, "pointer leave\n");
}


void
pointer_motion(void *data, struct wl_pointer *pointer, uint32_t time, wl_fixed_t x, wl_fixed_t y)
{
	fprintf(stderr, "pointer motion: (%i, %i)\n", x, y);
}


void
pointer_button(void *data, struct wl_pointer *pointer, uint32_t serial, uint32_t time, uint32_t button, uint32_t state)
{
	fprintf(stderr, "pointer button: (b: %i, s: %i)\n", button, state);
}


void
pointer_axis(void *data, struct wl_pointer *pointer, uint32_t time, uint32_t axis, wl_fixed_t value)
{
	fprintf(stderr, "pointer axis: (a: %i, v: %i)\n", axis, value);
}


void
setup()
{
	client.kb.repeat.timer = timerfd_create(CLOCK_MONOTONIC, 0);
	client.kb.context = xkb_context_new(XKB_CONTEXT_NO_FLAGS);
	client.display = wl_display_connect(0);
	client.registry = wl_display_get_registry(client.display);
	wl_registry_add_listener(client.registry, &registry_listener, &client);
	wl_display_roundtrip(client.display);

	xdg_wm_base_add_listener(client.wm_base, &wm_base_listener, &client);
	wl_display_roundtrip(client.display);

	client.pointer.pointer = wl_seat_get_pointer(client.seat);
	wl_pointer_add_listener(client.pointer.pointer, &pointer_listener, &client);

	win.surface.wl = wl_compositor_create_surface(client.compositor);
	win.surface.xdg = xdg_wm_base_get_xdg_surface(client.wm_base, win.surface.wl);
	xdg_surface_add_listener(win.surface.xdg, &surface_listener, &win);
	win.surface.toplevel = xdg_surface_get_toplevel(win.surface.xdg);
	xdg_toplevel_add_listener(win.surface.toplevel, &toplevel_listener, &win);
	xdg_toplevel_set_title(win.surface.toplevel, "swt");
	wl_surface_commit(win.surface.wl);
}


int main()
{
	struct itimerspec spec = { 0 };
	struct pollfd fds[2];

	setup();

	fds[0].fd = wl_display_get_fd(client.display);
	fds[0].events = POLLIN;
	fds[1].fd = client.kb.repeat.timer;
	fds[1].events = POLLIN;

	while (running) {
		if (wl_display_flush(client.display) < 0) {
			if (errno == EAGAIN)
				continue;
			break;
		}

		if (poll(fds, sizeof(fds) / sizeof(*fds), -1) < 0) {
			if (errno == EAGAIN)
				continue;
			break;
		}

		if (fds[0].revents & POLLIN) {
			if (wl_display_dispatch(client.display) < 0) {
				running = 0;
			}
		}

		if (fds[1].revents & POLLIN) {
			handle_keyboard_event();
			spec.it_value.tv_sec = client.kb.repeat.period / 1000;
			spec.it_value.tv_nsec = (client.kb.repeat.period % 1000) / 1000000;
			timerfd_settime(client.kb.repeat.timer, 0, &spec, 0);
		}
	}

	wl_display_disconnect(client.display);

	return 0;
}