#define _XOPEN_SOURCE 700
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <poll.h>
#include <signal.h>
#include <time.h>
#include <dbus/dbus.h>
#include "swaybar/tray/dbus.h"
#include "swaybar/event_loop.h"
#include "log.h"

DBusConnection *conn = NULL;

static void dispatch_watch(int fd, short mask, void *data) {
	sway_log(L_DEBUG, "Dispatching watch");
	DBusWatch *watch = data;

	if (!dbus_watch_get_enabled(watch)) {
		return;
	}

	uint32_t flags = 0;

	if (mask & POLLIN) {
		flags |= DBUS_WATCH_READABLE;
	} if (mask & POLLOUT) {
		flags |= DBUS_WATCH_WRITABLE;
	} if (mask & POLLHUP) {
		flags |= DBUS_WATCH_HANGUP;
	} if (mask & POLLERR) {
		flags |= DBUS_WATCH_ERROR;
	}

	dbus_watch_handle(watch, flags);
}

static dbus_bool_t add_watch(DBusWatch *watch, void *_data) {
	if (!dbus_watch_get_enabled(watch)) {
		// Watch should not be polled
		return TRUE;
	}

	short mask = 0;
	uint32_t flags = dbus_watch_get_flags(watch);

	if (flags & DBUS_WATCH_READABLE) {
		mask |= POLLIN;
	} if (flags & DBUS_WATCH_WRITABLE) {
		mask |= POLLOUT;
	}

	int fd = dbus_watch_get_unix_fd(watch);

	sway_log(L_DEBUG, "Adding DBus watch fd: %d", fd);
	add_event(fd, mask, dispatch_watch, watch);

	return TRUE;
}

static void remove_watch(DBusWatch *watch, void *_data) {
	int fd = dbus_watch_get_unix_fd(watch);

	remove_event(fd);
}

static void dispatch_timeout(timer_t timer, void *data) {
	sway_log(L_DEBUG, "Dispatching DBus timeout");
	DBusTimeout *timeout = data;

	if (dbus_timeout_get_enabled(timeout)) {
		dbus_timeout_handle(timeout);
	}
}

static dbus_bool_t add_timeout(DBusTimeout *timeout, void *_data) {
	if (!dbus_timeout_get_enabled(timeout)) {
		return TRUE;
	}

	timer_t *timer = malloc(sizeof(timer_t));
	if (!timer) {
		sway_log(L_ERROR, "Cannot allocate memory");
		return FALSE;
	}
	struct sigevent ev = {
		.sigev_notify = SIGEV_NONE,
	};

	if (timer_create(CLOCK_MONOTONIC, &ev, timer)) {
		sway_log(L_ERROR, "Could not create DBus timer");
		return FALSE;
	}

	int interval = dbus_timeout_get_interval(timeout);
	int interval_sec = interval / 1000;
	int interval_msec = (interval_sec * 1000) - interval;

	struct timespec period = {
		(time_t) interval_sec,
		((long) interval_msec) * 1000 * 1000,
	};
	struct itimerspec time = {
		period,
		period,
	};

	timer_settime(*timer, 0, &time, NULL);

	dbus_timeout_set_data(timeout, timer, free);

	sway_log(L_DEBUG, "Adding DBus timeout. Interval: %ds %dms", interval_sec, interval_msec);
	add_timer(*timer, dispatch_timeout, timeout);

	return TRUE;
}
static void remove_timeout(DBusTimeout *timeout, void *_data) {
	timer_t *timer = (timer_t *) dbus_timeout_get_data(timeout);
	sway_log(L_DEBUG, "Removing DBus timeout.");

	if (timer) {
		remove_timer(*timer);
	}
}

static bool should_dispatch = true;

static void dispatch_status(DBusConnection *connection, DBusDispatchStatus new_status,
		void *_data) {
	if (new_status == DBUS_DISPATCH_DATA_REMAINS) {
		should_dispatch = true;
	}
}

/* Public functions below */

void dispatch_dbus() {
	if (!should_dispatch) {
		return;
	}

	DBusDispatchStatus status;

	do {
		status = dbus_connection_dispatch(conn);
	} while (status == DBUS_DISPATCH_DATA_REMAINS);

	if (status != DBUS_DISPATCH_COMPLETE) {
		sway_log(L_ERROR, "Cannot dispatch dbus events: %d", status);
	}

	should_dispatch = false;
}

int dbus_init() {
	DBusError error;
	dbus_error_init(&error);

	conn = dbus_bus_get(DBUS_BUS_SESSION, &error);
	if (conn == NULL) {
		sway_log(L_INFO, "Compiled with dbus support, but unable to connect to dbus");
		sway_log(L_INFO, "swaybar will be unable to display tray icons.");
		return -1;
	}

	dbus_connection_set_exit_on_disconnect(conn, FALSE);
	if (dbus_error_is_set(&error)) {
		sway_log(L_ERROR, "Cannot get bus connection: %s\n", error.message);
		conn = NULL;
		return -1;
	}

	sway_log(L_INFO, "Unique name: %s\n", dbus_bus_get_unique_name(conn));

	// Will be called if dispatch status changes
	dbus_connection_set_dispatch_status_function(conn, dispatch_status, NULL, NULL);

	if (!dbus_connection_set_watch_functions(conn, add_watch, remove_watch,
			NULL, NULL, NULL)) {
		dbus_connection_set_watch_functions(conn, NULL, NULL, NULL, NULL, NULL);
		sway_log(L_ERROR, "Failed to activate DBUS watch functions");
		return -1;
	}

	if (!dbus_connection_set_timeout_functions(conn, add_timeout, remove_timeout,
			NULL, NULL, NULL)) {
		dbus_connection_set_watch_functions(conn, NULL, NULL, NULL, NULL, NULL);
		dbus_connection_set_timeout_functions(conn, NULL, NULL, NULL, NULL, NULL);
		sway_log(L_ERROR, "Failed to activate DBUS timeout functions");
		return -1;
	}

	return 0;
}