# 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 __future__ import annotations

from airflow.utils.state import TaskInstanceState

EXECUTION_STATES = {
    TaskInstanceState.RUNNING,
    TaskInstanceState.QUEUED,
}

# States counted for task-level concurrency limits (max_active_tis_per_dag /
# max_active_tis_per_dagrun). DEFERRED is included because a deferred task
# instance is still logically in-flight and must block additional instances
# from being scheduled. This is intentionally separate from EXECUTION_STATES
# so that DAG-level max_active_tasks and pool slot calculations are unaffected.
ACTIVE_STATES = {
    *EXECUTION_STATES,
    TaskInstanceState.DEFERRED,
    # AWAITING_INPUT (HITL) is logically in-flight like DEFERRED: it counts towards task-level
    # concurrency (max_active_tis_per_dag / max_active_tis_per_dagrun) and, like DEFERRED, is
    # excluded from DAG-run active-task accounting. It is also excluded from pool slot accounting,
    # but -- unlike DEFERRED, which a pool can opt to count via ``include_deferred`` -- an
    # awaiting_input task is *never* counted against pool slots: an open-ended human wait should
    # not reserve one.
    TaskInstanceState.AWAITING_INPUT,
}

# In order to be able to get queued a task must have one of these states
SCHEDULEABLE_STATES = {
    None,
    TaskInstanceState.UP_FOR_RETRY,
    TaskInstanceState.UP_FOR_RESCHEDULE,
}

RUNNABLE_STATES = {
    # For cases like unit tests and run manually
    None,
    TaskInstanceState.UP_FOR_RETRY,
    TaskInstanceState.UP_FOR_RESCHEDULE,
    # For normal scheduler/backfill cases
    TaskInstanceState.QUEUED,
}

QUEUEABLE_STATES = {
    TaskInstanceState.SCHEDULED,
}
