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"""
Example Airflow DAG for testing Google Dataflow Beam Pipeline Operator with Asynchronous Python.
"""
from __future__ import annotations

import os
from datetime import datetime
from pathlib import Path
from typing import Callable

from airflow import models
from airflow.exceptions import AirflowException
from airflow.providers.apache.beam.hooks.beam import BeamRunnerType
from airflow.providers.apache.beam.operators.beam import BeamRunPythonPipelineOperator
from airflow.providers.google.cloud.hooks.dataflow import DataflowJobStatus
from airflow.providers.google.cloud.operators.gcs import GCSCreateBucketOperator, GCSDeleteBucketOperator
from airflow.providers.google.cloud.sensors.dataflow import (
    DataflowJobAutoScalingEventsSensor,
    DataflowJobMessagesSensor,
    DataflowJobMetricsSensor,
    DataflowJobStatusSensor,
)
from airflow.providers.google.cloud.transfers.local_to_gcs import LocalFilesystemToGCSOperator
from airflow.utils.trigger_rule import TriggerRule

ENV_ID = os.environ.get("SYSTEM_TESTS_ENV_ID")
DAG_ID = "dataflow_native_python_async"

BUCKET_NAME = f"bucket_{DAG_ID}_{ENV_ID}"

PYTHON_FILE_NAME = "wordcount_debugging.txt"
GCS_TMP = f"gs://{BUCKET_NAME}/temp/"
GCS_STAGING = f"gs://{BUCKET_NAME}/staging/"
GCS_OUTPUT = f"gs://{BUCKET_NAME}/output"
GCS_PYTHON_SCRIPT = f"gs://{BUCKET_NAME}/{PYTHON_FILE_NAME}"
PYTHON_FILE_LOCAL_PATH = str(Path(__file__).parent / "resources" / PYTHON_FILE_NAME)
LOCATION = "europe-west3"

default_args = {
    "dataflow_default_options": {
        "tempLocation": GCS_TMP,
        "stagingLocation": GCS_STAGING,
    }
}

with models.DAG(
    DAG_ID,
    default_args=default_args,
    schedule="@once",
    start_date=datetime(2021, 1, 1),
    catchup=False,
    tags=["example", "dataflow"],
) as dag:
    create_bucket = GCSCreateBucketOperator(task_id="create_bucket", bucket_name=BUCKET_NAME)

    upload_file = LocalFilesystemToGCSOperator(
        task_id="upload_file_to_bucket",
        src=PYTHON_FILE_LOCAL_PATH,
        dst=PYTHON_FILE_NAME,
        bucket=BUCKET_NAME,
    )

    # [START howto_operator_start_python_job_async]
    start_python_job_async = BeamRunPythonPipelineOperator(
        task_id="start_python_job_async",
        runner=BeamRunnerType.DataflowRunner,
        py_file=GCS_PYTHON_SCRIPT,
        py_options=[],
        pipeline_options={
            "output": GCS_OUTPUT,
        },
        py_requirements=["apache-beam[gcp]==2.46.0"],
        py_interpreter="python3",
        py_system_site_packages=False,
        dataflow_config={
            "job_name": "start_python_job_async",
            "location": LOCATION,
            "wait_until_finished": False,
        },
    )
    # [END howto_operator_start_python_job_async]

    # [START howto_sensor_wait_for_job_status]
    wait_for_python_job_async_done = DataflowJobStatusSensor(
        task_id="wait_for_python_job_async_done",
        job_id="{{task_instance.xcom_pull('start_python_job_async')['dataflow_job_id']}}",
        expected_statuses={DataflowJobStatus.JOB_STATE_DONE},
        location=LOCATION,
    )
    # [END howto_sensor_wait_for_job_status]

    # [START howto_sensor_wait_for_job_metric]
    def check_metric_scalar_gte(metric_name: str, value: int) -> Callable:
        """Check is metric greater than equals to given value."""

        def callback(metrics: list[dict]) -> bool:
            dag.log.info("Looking for '%s' >= %d", metric_name, value)
            for metric in metrics:
                context = metric.get("name", {}).get("context", {})
                original_name = context.get("original_name", "")
                tentative = context.get("tentative", "")
                if original_name == "Service-cpu_num_seconds" and not tentative:
                    return metric["scalar"] >= value
            raise AirflowException(f"Metric '{metric_name}' not found in metrics")

        return callback

    wait_for_python_job_async_metric = DataflowJobMetricsSensor(
        task_id="wait_for_python_job_async_metric",
        job_id="{{task_instance.xcom_pull('start_python_job_async')['dataflow_job_id']}}",
        location=LOCATION,
        callback=check_metric_scalar_gte(metric_name="Service-cpu_num_seconds", value=100),
        fail_on_terminal_state=False,
    )
    # [END howto_sensor_wait_for_job_metric]

    # [START howto_sensor_wait_for_job_message]
    def check_message(messages: list[dict]) -> bool:
        """Check message"""
        for message in messages:
            if "Adding workflow start and stop steps." in message.get("messageText", ""):
                return True
        return False

    wait_for_python_job_async_message = DataflowJobMessagesSensor(
        task_id="wait_for_python_job_async_message",
        job_id="{{task_instance.xcom_pull('start_python_job_async')['dataflow_job_id']}}",
        location=LOCATION,
        callback=check_message,
        fail_on_terminal_state=False,
    )
    # [END howto_sensor_wait_for_job_message]

    # [START howto_sensor_wait_for_job_autoscaling_event]
    def check_autoscaling_event(autoscaling_events: list[dict]) -> bool:
        """Check autoscaling event"""
        for autoscaling_event in autoscaling_events:
            if "Worker pool started." in autoscaling_event.get("description", {}).get("messageText", ""):
                return True
        return False

    wait_for_python_job_async_autoscaling_event = DataflowJobAutoScalingEventsSensor(
        task_id="wait_for_python_job_async_autoscaling_event",
        job_id="{{task_instance.xcom_pull('start_python_job_async')['dataflow_job_id']}}",
        location=LOCATION,
        callback=check_autoscaling_event,
        fail_on_terminal_state=False,
    )
    # [END howto_sensor_wait_for_job_autoscaling_event]

    delete_bucket = GCSDeleteBucketOperator(
        task_id="delete_bucket", bucket_name=BUCKET_NAME, trigger_rule=TriggerRule.ALL_DONE
    )

    (
        # TEST SETUP
        create_bucket
        >> upload_file
        # TEST BODY
        >> start_python_job_async
        >> [
            wait_for_python_job_async_done,
            wait_for_python_job_async_metric,
            wait_for_python_job_async_message,
            wait_for_python_job_async_autoscaling_event,
        ]
        # TEST TEARDOWN
        >> delete_bucket
    )

    from tests.system.utils.watcher import watcher

    # This test needs watcher in order to properly mark success/failure
    # when "teardown" task with trigger rule is part of the DAG
    list(dag.tasks) >> watcher()


from tests.system.utils import get_test_run  # noqa: E402

# Needed to run the example DAG with pytest (see: tests/system/README.md#run_via_pytest)
test_run = get_test_run(dag)
