class DateSet(EverythingSet):

	_operations = ["merge", "unmerge"]

	def __init__(self, vardb, date, mode="older"):

		super(DateSet, self).__init__(vardb)

		self._mode = mode

		self._date = date

	def _filter(self, atom):

		cpv = self._db.match(atom)[0]

		path = self._db.getpath(cpv, filename="COUNTER")

		date = os.stat(path).st_mtime

		# Make sure inequality is _strict_ to exclude tested package

		if ((self._mode == "older" and date < self._date) \

			or (self._mode == "newer" and date > self._date)):

			return True

		else:

			return False

	def singleBuilder(cls, options, settings, trees):

		vardbapi = trees["vartree"].dbapi

		mode = options.get("mode", "older")

		if str(mode).lower() not in ["newer", "older"]:

			raise SetConfigError(_("invalid 'mode' value %s (use either 'newer' or 'older')") % mode)

		package = options.get("package")

		if package is not None:

			format = "package"

		else:

			filestamp = options.get("filestamp")

			if filestamp is not None:

				format = "filestamp"

			else:

				seconds = options.get("seconds")

				if seconds is not None:

					format = "seconds"

				else:

					dateopt = options.get("date")

					if dateopt is not None:

						format = "date"

					else:

						raise SetConfigError(_("none of these options specified: 'package', 'filestamp', 'seconds', 'date'"))

		if (format == "package"):

			try:

				cpv = vardbapi.match(package)[0]

				path = vardbapi.getpath(cpv, filename="COUNTER")

				date = os.stat(path).st_mtime

			except ValueError as e:

				raise SetConfigError(_("cannot determine installation date of package %s") % package)

		elif (format == "filestamp"):

			try:

				date = os.stat(filestamp).st_mtime

			except ValueError as e:

				raise SetConfigError(_("cannot determine 'filestamp' of '%s'") % s)

		elif (format == "seconds"):

			# Do *not* test for integer:

			# Modern filesystems support fractional seconds

			date = seconds

		else:

			try:

				dateformat = options.get("dateformat", "%x %X")

				date = time.mktime(time.strptime(dateopt, dateformat))

			except ValueError as e:

				raise SetConfigError(_("'date=%s' does not match 'dateformat=%s'") % (dateopt, dateformat))

		return DateSet(vardb=vardbapi, date=date, mode=mode)

	singleBuilder = classmethod(singleBuilder)