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"""
Example DAG demonstrating the usage of BranchDayOfWeekOperator.
"""
from __future__ import annotations

import pendulum

from airflow import DAG
from airflow.operators.empty import EmptyOperator
from airflow.operators.weekday import BranchDayOfWeekOperator
from airflow.utils.weekday import WeekDay

with DAG(
    dag_id="example_weekday_branch_operator",
    start_date=pendulum.datetime(2021, 1, 1, tz="UTC"),
    catchup=False,
    tags=["example"],
    schedule="@daily",
) as dag:
    # [START howto_operator_day_of_week_branch]
    empty_task_1 = EmptyOperator(task_id='branch_true')
    empty_task_2 = EmptyOperator(task_id='branch_false')
    empty_task_3 = EmptyOperator(task_id='branch_weekend')
    empty_task_4 = EmptyOperator(task_id='branch_mid_week')

    branch = BranchDayOfWeekOperator(
        task_id="make_choice",
        follow_task_ids_if_true="branch_true",
        follow_task_ids_if_false="branch_false",
        week_day="Monday",
    )
    branch_weekend = BranchDayOfWeekOperator(
        task_id="make_weekend_choice",
        follow_task_ids_if_true="branch_weekend",
        follow_task_ids_if_false="branch_mid_week",
        week_day={WeekDay.SATURDAY, WeekDay.SUNDAY},
    )

    # Run empty_task_1 if branch executes on Monday, empty_task_2 otherwise
    branch >> [empty_task_1, empty_task_2]
    # Run empty_task_3 if it's a weekend, empty_task_4 otherwise
    empty_task_2 >> branch_weekend >> [empty_task_3, empty_task_4]
    # [END howto_operator_day_of_week_branch]
