#include <hikari/cursor.h>

#include <assert.h>
#include <errno.h>

#include <wlr/types/wlr_seat.h>
#include <wlr/types/wlr_xcursor_manager.h>

#include <hikari/binding.h>
#include <hikari/binding_config.h>
#include <hikari/memory.h>
#include <hikari/output.h>
#include <hikari/server.h>

static void
motion_absolute_handler(struct wl_listener *listener, void *data);

static void
frame_handler(struct wl_listener *listener, void *data);

static void
motion_handler(struct wl_listener *listener, void *data);

static void
button_handler(struct wl_listener *listener, void *data);

static void
axis_handler(struct wl_listener *listener, void *data);

static void
request_set_cursor_handler(struct wl_listener *listener, void *data);

static void
surface_destroy_handler(struct wl_listener *listener, void *data);

static unsigned long
get_cursor_size(void)
{
	const char *cursor_size = getenv("XCURSOR_SIZE");

	if (cursor_size != NULL && strlen(cursor_size) > 0) {
		errno = 0;
		char *end;
		unsigned long size = strtoul(cursor_size, &end, 10);
		if (*end == '\0' && errno == 0) {
			return size;
		}
	}

	setenv("XCURSOR_SIZE", "16", 1);

	return 16;
}

static const char *
get_cursor_theme(void)
{
	char *cursor_theme = getenv("XCURSOR_THEME");

	if (cursor_theme != NULL && strlen(cursor_theme) > 0) {
		return cursor_theme;
	}

	setenv("XCURSOR_THEME", "Adwaita", 1);

	return "Adwaita";
}

static void
configure_bindings(struct hikari_cursor *cursor, struct wl_list *bindings)
{
	int nr[256] = { 0 };
	struct hikari_binding_config *binding_config;
	wl_list_for_each (binding_config, bindings, link) {
		nr[binding_config->key.modifiers]++;
	}

	for (int mask = 0; mask < 256; mask++) {
		cursor->bindings[mask].nbindings = nr[mask];
		if (nr[mask] != 0) {
			cursor->bindings[mask].bindings =
					hikari_calloc(nr[mask], sizeof(struct hikari_binding));
		} else {
			cursor->bindings[mask].bindings = NULL;
		}

		nr[mask] = 0;
	}

	wl_list_for_each (binding_config, bindings, link) {
		uint8_t mask = binding_config->key.modifiers;
		struct hikari_binding *binding = &cursor->bindings[mask].bindings[nr[mask]];

		binding->action = &binding_config->action;

		switch (binding_config->key.type) {
			case HIKARI_ACTION_BINDING_KEY_KEYCODE:
				binding->keycode = binding_config->key.value.keycode;
				break;

			case HIKARI_ACTION_BINDING_KEY_KEYSYM:
				assert(false);
				break;
		}

		nr[mask]++;
	}
}

void
hikari_cursor_init(
		struct hikari_cursor *cursor, struct wlr_output_layout *output_layout)
{
	struct wlr_cursor *wlr_cursor = wlr_cursor_create();

	wlr_cursor_attach_output_layout(wlr_cursor, output_layout);

	const char *cursor_theme = get_cursor_theme();
	unsigned long cursor_size = get_cursor_size();

	cursor->cursor_mgr = wlr_xcursor_manager_create(cursor_theme, cursor_size);
	wlr_xcursor_manager_load(cursor->cursor_mgr, 1);

	cursor->wlr_cursor = wlr_cursor;

	wl_list_init(&cursor->surface_destroy.link);
	hikari_binding_group_init(cursor->bindings);
}

void
hikari_cursor_configure_bindings(
		struct hikari_cursor *cursor, struct wl_list *bindings)
{
	hikari_binding_group_fini(cursor->bindings);
	hikari_binding_group_init(cursor->bindings);
	configure_bindings(cursor, bindings);
}

void
hikari_cursor_fini(struct hikari_cursor *cursor)
{
	hikari_binding_group_fini(cursor->bindings);
	hikari_cursor_deactivate(cursor);

	wlr_xcursor_manager_destroy(cursor->cursor_mgr);
}

void
hikari_cursor_activate(struct hikari_cursor *cursor)
{
	struct wlr_cursor *wlr_cursor = cursor->wlr_cursor;

	cursor->motion_absolute.notify = motion_absolute_handler;
	wl_signal_add(&wlr_cursor->events.motion_absolute, &cursor->motion_absolute);

	cursor->frame.notify = frame_handler;
	wl_signal_add(&wlr_cursor->events.frame, &cursor->frame);

	cursor->motion.notify = motion_handler;
	wl_signal_add(&wlr_cursor->events.motion, &cursor->motion);

	cursor->button.notify = button_handler;
	wl_signal_add(&wlr_cursor->events.button, &cursor->button);

	cursor->axis.notify = axis_handler;
	wl_signal_add(&wlr_cursor->events.axis, &cursor->axis);

	cursor->request_set_cursor.notify = request_set_cursor_handler;
	wl_signal_add(&hikari_server.seat->events.request_set_cursor,
			&cursor->request_set_cursor);

	hikari_cursor_reset_image(cursor);
}

void
hikari_cursor_deactivate(struct hikari_cursor *cursor)
{
	wl_list_remove(&cursor->motion_absolute.link);
	wl_list_remove(&cursor->frame.link);
	wl_list_remove(&cursor->motion.link);
	wl_list_remove(&cursor->button.link);
	wl_list_remove(&cursor->axis.link);
	wl_list_remove(&cursor->request_set_cursor.link);

	hikari_cursor_set_image(cursor, NULL);
}

void
hikari_cursor_set_image(struct hikari_cursor *cursor, const char *path)
{
	wl_list_remove(&cursor->surface_destroy.link);
	wl_list_init(&cursor->surface_destroy.link);

	if (path != NULL) {
		wlr_xcursor_manager_set_cursor_image(
				cursor->cursor_mgr, path, cursor->wlr_cursor);
	} else {
		wlr_cursor_set_image(cursor->wlr_cursor, NULL, 0, 0, 0, 0, 0, 0);
	}
}

void
hikari_cursor_center(struct hikari_cursor *cursor,
		struct hikari_output *output,
		struct wlr_box *geometry)
{
	int x = output->geometry.x + geometry->x + geometry->width / 2;
	int y = output->geometry.y + geometry->y + geometry->height / 2;

	hikari_cursor_warp(cursor, x, y);
}

static void
motion_absolute_handler(struct wl_listener *listener, void *data)
{
	struct hikari_cursor *cursor =
			wl_container_of(listener, cursor, motion_absolute);

	assert(!hikari_server_in_lock_mode());

	struct wlr_event_pointer_motion_absolute *event = data;

	wlr_cursor_warp_absolute(
			cursor->wlr_cursor, event->device, event->x, event->y);

	hikari_server.mode->cursor_move(event->time_msec);
}

static void
frame_handler(struct wl_listener *listener, void *data)
{
	assert(!hikari_server_in_lock_mode());

	wlr_seat_pointer_notify_frame(hikari_server.seat);
}

static void
motion_handler(struct wl_listener *listener, void *data)
{
	struct hikari_cursor *cursor = wl_container_of(listener, cursor, motion);

	assert(!hikari_server_in_lock_mode());

	struct wlr_event_pointer_motion *event = data;

	wlr_cursor_move(
			cursor->wlr_cursor, event->device, event->delta_x, event->delta_y);

	hikari_server.mode->cursor_move(event->time_msec);
}

static void
button_handler(struct wl_listener *listener, void *data)
{
	assert(!hikari_server_in_lock_mode());

	struct hikari_cursor *cursor = wl_container_of(listener, cursor, button);
	struct wlr_event_pointer_button *event = data;

	hikari_server.mode->button_handler(cursor, event);
}

static void
axis_handler(struct wl_listener *listener, void *data)
{
	assert(!hikari_server_in_lock_mode());

	struct wlr_event_pointer_axis *event = data;

	wlr_seat_pointer_notify_axis(hikari_server.seat,
			event->time_msec,
			event->orientation,
			event->delta,
			event->delta_discrete,
			event->source);
}

static void
request_set_cursor_handler(struct wl_listener *listener, void *data)
{
	if (!hikari_server_in_normal_mode()) {
		return;
	}

	struct hikari_cursor *cursor =
			wl_container_of(listener, cursor, request_set_cursor);

	struct hikari_server *server = &hikari_server;
	struct wlr_seat_pointer_request_set_cursor_event *event = data;
	struct wlr_seat *seat = server->seat;

	struct wl_client *focused_client = NULL;
	struct wlr_surface *focused_surface = seat->pointer_state.focused_surface;
	if (focused_surface != NULL) {
		focused_client = wl_resource_get_client(focused_surface->resource);
	}

	if (focused_client == NULL || event->seat_client->client != focused_client) {
		return;
	}

	struct wlr_surface *surface = event->surface;

	wl_list_remove(&cursor->surface_destroy.link);
	if (surface != NULL) {
		cursor->surface_destroy.notify = surface_destroy_handler;
		wl_signal_add(&surface->events.destroy, &cursor->surface_destroy);
	} else {
		wl_list_init(&cursor->surface_destroy.link);
	}

	wlr_cursor_set_surface(
			cursor->wlr_cursor, surface, event->hotspot_x, event->hotspot_y);
}

static void
surface_destroy_handler(struct wl_listener *listener, void *data)
{
	struct hikari_cursor *cursor =
			wl_container_of(listener, cursor, surface_destroy);

	hikari_cursor_reset_image(cursor);
}