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"""
Example Airflow DAG that demonstrates interactions with Google Cloud Transfer.


This DAG relies on the following OS environment variables

* GCP_PROJECT_ID - Google Cloud Project to use for the Google Cloud Transfer Service.
* GCP_TRANSFER_FIRST_TARGET_BUCKET - Google Cloud Storage bucket to which files are copied from AWS.
  It is also a source bucket in next step
* GCP_TRANSFER_SECOND_TARGET_BUCKET - Google Cloud Storage bucket to which files are copied
"""

import os
from datetime import datetime, timedelta

from airflow import models
from airflow.providers.google.cloud.hooks.cloud_storage_transfer_service import (
    ALREADY_EXISTING_IN_SINK,
    BUCKET_NAME,
    DESCRIPTION,
    FILTER_JOB_NAMES,
    FILTER_PROJECT_ID,
    GCS_DATA_SINK,
    GCS_DATA_SOURCE,
    PROJECT_ID,
    SCHEDULE,
    SCHEDULE_END_DATE,
    SCHEDULE_START_DATE,
    START_TIME_OF_DAY,
    STATUS,
    TRANSFER_JOB,
    TRANSFER_JOB_FIELD_MASK,
    TRANSFER_OPTIONS,
    TRANSFER_SPEC,
    GcpTransferJobsStatus,
    GcpTransferOperationStatus,
)
from airflow.providers.google.cloud.operators.cloud_storage_transfer_service import (
    CloudDataTransferServiceCreateJobOperator,
    CloudDataTransferServiceDeleteJobOperator,
    CloudDataTransferServiceGetOperationOperator,
    CloudDataTransferServiceListOperationsOperator,
    CloudDataTransferServiceUpdateJobOperator,
)
from airflow.providers.google.cloud.sensors.cloud_storage_transfer_service import (
    CloudDataTransferServiceJobStatusSensor,
)
from airflow.utils.dates import days_ago

GCP_PROJECT_ID = os.environ.get("GCP_PROJECT_ID", "example-project")
GCP_TRANSFER_FIRST_TARGET_BUCKET = os.environ.get(
    "GCP_TRANSFER_FIRST_TARGET_BUCKET", "gcp-transfer-first-target"
)
GCP_TRANSFER_SECOND_TARGET_BUCKET = os.environ.get(
    "GCP_TRANSFER_SECOND_TARGET_BUCKET", "gcp-transfer-second-target"
)

# [START howto_operator_gcp_transfer_create_job_body_gcp]
gcs_to_gcs_transfer_body = {
    DESCRIPTION: "description",
    STATUS: GcpTransferJobsStatus.ENABLED,
    PROJECT_ID: GCP_PROJECT_ID,
    SCHEDULE: {
        SCHEDULE_START_DATE: datetime(2015, 1, 1).date(),
        SCHEDULE_END_DATE: datetime(2030, 1, 1).date(),
        START_TIME_OF_DAY: (datetime.utcnow() + timedelta(seconds=120)).time(),
    },
    TRANSFER_SPEC: {
        GCS_DATA_SOURCE: {BUCKET_NAME: GCP_TRANSFER_FIRST_TARGET_BUCKET},
        GCS_DATA_SINK: {BUCKET_NAME: GCP_TRANSFER_SECOND_TARGET_BUCKET},
        TRANSFER_OPTIONS: {ALREADY_EXISTING_IN_SINK: True},
    },
}
# [END howto_operator_gcp_transfer_create_job_body_gcp]

# [START howto_operator_gcp_transfer_update_job_body]
update_body = {
    PROJECT_ID: GCP_PROJECT_ID,
    TRANSFER_JOB: {DESCRIPTION: "description_updated"},
    TRANSFER_JOB_FIELD_MASK: "description",
}
# [END howto_operator_gcp_transfer_update_job_body]

with models.DAG(
    "example_gcp_transfer",
    schedule_interval='@once',  # Override to match your needs
    start_date=days_ago(1),
    tags=["example"],
) as dag:

    create_transfer = CloudDataTransferServiceCreateJobOperator(
        task_id="create_transfer", body=gcs_to_gcs_transfer_body
    )

    # [START howto_operator_gcp_transfer_update_job]
    update_transfer = CloudDataTransferServiceUpdateJobOperator(
        task_id="update_transfer",
        job_name="{{task_instance.xcom_pull('create_transfer')['name']}}",
        body=update_body,
    )
    # [END howto_operator_gcp_transfer_update_job]

    wait_for_transfer = CloudDataTransferServiceJobStatusSensor(
        task_id="wait_for_transfer",
        job_name="{{task_instance.xcom_pull('create_transfer')['name']}}",
        project_id=GCP_PROJECT_ID,
        expected_statuses={GcpTransferOperationStatus.SUCCESS},
    )

    list_operations = CloudDataTransferServiceListOperationsOperator(
        task_id="list_operations",
        request_filter={
            FILTER_PROJECT_ID: GCP_PROJECT_ID,
            FILTER_JOB_NAMES: ["{{task_instance.xcom_pull('create_transfer')['name']}}"],
        },
    )

    get_operation = CloudDataTransferServiceGetOperationOperator(
        task_id="get_operation",
        operation_name="{{task_instance.xcom_pull('list_operations')[0]['name']}}",
    )

    delete_transfer = CloudDataTransferServiceDeleteJobOperator(
        task_id="delete_transfer_from_gcp_job",
        job_name="{{task_instance.xcom_pull('create_transfer')['name']}}",
        project_id=GCP_PROJECT_ID,
    )

    create_transfer >> wait_for_transfer >> update_transfer >> list_operations >> get_operation
    get_operation >> delete_transfer
