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"""
Example Airflow DAG to submit Apache Spark applications using
`SparkSubmitOperator`, `SparkJDBCOperator` and `SparkSqlOperator`.
"""

from __future__ import annotations

import os
from datetime import datetime

from airflow.models import DAG
from airflow.providers.apache.spark.operators.spark_jdbc import SparkJDBCOperator
from airflow.providers.apache.spark.operators.spark_pyspark import PySparkOperator
from airflow.providers.apache.spark.operators.spark_sql import SparkSqlOperator
from airflow.providers.apache.spark.operators.spark_submit import SparkSubmitOperator

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

with DAG(
    dag_id=DAG_ID,
    schedule=None,
    start_date=datetime(2021, 1, 1),
    catchup=False,
    tags=["example"],
) as dag:
    # [START howto_operator_spark_submit]
    submit_job = SparkSubmitOperator(
        application="${SPARK_HOME}/examples/src/main/python/pi.py", task_id="submit_job"
    )
    # [END howto_operator_spark_submit]

    # [START howto_operator_spark_jdbc]
    jdbc_to_spark_job = SparkJDBCOperator(
        cmd_type="jdbc_to_spark",
        jdbc_table="foo",
        spark_jars="${SPARK_HOME}/jars/postgresql-42.2.12.jar",
        jdbc_driver="org.postgresql.Driver",
        metastore_table="bar",
        save_mode="overwrite",
        save_format="JSON",
        task_id="jdbc_to_spark_job",
    )

    spark_to_jdbc_job = SparkJDBCOperator(
        cmd_type="spark_to_jdbc",
        jdbc_table="foo",
        spark_jars="${SPARK_HOME}/jars/postgresql-42.2.12.jar",
        jdbc_driver="org.postgresql.Driver",
        metastore_table="bar",
        save_mode="append",
        task_id="spark_to_jdbc_job",
    )
    # [END howto_operator_spark_jdbc]

    # [START howto_operator_spark_sql]
    spark_sql_job = SparkSqlOperator(
        sql="SELECT COUNT(1) as cnt FROM temp_table", master="local", task_id="spark_sql_job"
    )
    # [END howto_operator_spark_sql]

    # [START howto_operator_spark_pyspark]
    def my_pyspark_job(spark):
        df = spark.range(100).filter("id % 2 = 0")
        print(df.count())

    spark_pyspark_job = PySparkOperator(
        python_callable=my_pyspark_job, conn_id="spark_connect", task_id="spark_pyspark_job"
    )
    # [END howto_operator_spark_pyspark]

from tests_common.test_utils.system_tests import get_test_run  # noqa: E402

# Needed to run the example DAG with pytest (see: contributing-docs/testing/system_tests.rst)
test_run = get_test_run(dag)
