text: # -*- coding: utf-8 -*-
  #
  # Licensed to the Apache Software Foundation (ASF) under one
  # or more contributor license agreements.  See the NOTICE file
  # distributed with this work for additional information
  # regarding copyright ownership.  The ASF licenses this file
  # to you under the Apache License, Version 2.0 (the
  # "License"); you may not use this file except in compliance
  # with the License.  You may obtain a copy of the License at
  #
  #   http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing,
  # software distributed under the License is distributed on an
  # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  # KIND, either express or implied.  See the License for the
  # specific language governing permissions and limitations
  # under the License.
  
  from airflow.contrib.utils.weekday import WeekDay
  from airflow.sensors.base_sensor_operator import BaseSensorOperator
  from airflow.utils import timezone
  from airflow.utils.decorators import apply_defaults
  
  
  class DayOfWeekSensor(BaseSensorOperator):
      """
      Waits until the first specified day of the week. For example, if the execution
      day of the task is '2018-12-22' (Saturday) and you pass 'FRIDAY', the task will wait
      until next Friday.
  
      **Example** (with single day): ::
  
          weekend_check = DayOfWeekSensor(
              task_id='weekend_check',
              week_day='Saturday',
              use_task_execution_day=True,
              dag=dag)
  
      **Example** (with multiple day using set): ::
  
          weekend_check = DayOfWeekSensor(
              task_id='weekend_check',
              week_day={'Saturday', 'Sunday'},
              use_task_execution_day=True,
              dag=dag)
  
      **Example** (with :class:`~airflow.contrib.utils.weekday.WeekDay` enum): ::
  
          # import WeekDay Enum
          from airflow.contrib.utils.weekday import WeekDay
  
          weekend_check = DayOfWeekSensor(
              task_id='weekend_check',
              week_day={WeekDay.SATURDAY, WeekDay.SUNDAY},
              use_task_execution_day=True,
              dag=dag)
  
      :param week_day: Day of the week to check (full name). Optionally, a set
          of days can also be provided using a set.
          Example values:
  
              * ``"MONDAY"``,
              * ``{"Saturday", "Sunday"}``
              * ``{WeekDay.TUESDAY}``
              * ``{WeekDay.SATURDAY, WeekDay.SUNDAY}``
  
      :type week_day: set or str or airflow.contrib.utils.weekday.WeekDay
      :param use_task_execution_day: If ``True``, uses task's execution day to compare
          with week_day. Execution Date is Useful for backfilling.
          If ``False``, uses system's day of the week. Useful when you
          don't want to run anything on weekdays on the system.
      :type use_task_execution_day: bool
      """
  
      @apply_defaults
      def __init__(self, week_day,
                   use_task_execution_day=False,
                   *args, **kwargs):
          super().__init__(*args, **kwargs)
          self.week_day = week_day
          self.use_task_execution_day = use_task_execution_day
          if isinstance(self.week_day, str):
              self._week_day_num = {WeekDay.get_weekday_number(week_day_str=self.week_day)}
          elif isinstance(self.week_day, WeekDay):
              self._week_day_num = {self.week_day}
          elif isinstance(self.week_day, set):
              if all(isinstance(day, str) for day in self.week_day):
                  self._week_day_num = {WeekDay.get_weekday_number(day) for day in week_day}
              elif all(isinstance(day, WeekDay) for day in self.week_day):
                  self._week_day_num = self.week_day
          else:
              raise TypeError(
                  'Unsupported Type for week_day parameter: {}. It should be one of str'
                  ', set or Weekday enum type'.format(type(week_day)))
  
      def poke(self, context):
          self.log.info('Poking until weekday is in %s, Today is %s',
                        self.week_day,
                        WeekDay(timezone.utcnow().isoweekday()).name)
          if self.use_task_execution_day:
              return context['execution_date'].isoweekday() in self._week_day_num
          else:
              return timezone.utcnow().isoweekday() in self._week_day_num
  