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# to you under the Apache License, Version 2.0 (the
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"""
Example use of Snowflake related operators.
"""
from airflow import DAG
from airflow.providers.snowflake.operators.snowflake import SnowflakeOperator
from airflow.providers.snowflake.transfers.s3_to_snowflake import S3ToSnowflakeOperator
from airflow.providers.snowflake.transfers.snowflake_to_slack import (
    SnowflakeToSlackOperator,
)
from airflow.utils.dates import days_ago

SNOWFLAKE_CONN_ID = "my_snowflake_conn"
SLACK_CONN_ID = "my_slack_conn"
# TODO: should be able to rely on connection's schema, but currently param required by S3ToSnowflakeTransfer
SNOWFLAKE_SCHEMA = "schema_name"
SNOWFLAKE_STAGE = "stage_name"
SNOWFLAKE_WAREHOUSE = "warehouse_name"
SNOWFLAKE_DATABASE = "database_name"
SNOWFLAKE_ROLE = "role_name"
SNOWFLAKE_SAMPLE_TABLE = "sample_table"
S3_FILE_PATH = "</path/to/file/sample_file.csv"

# SQL commands
CREATE_TABLE_SQL_STRING = f"CREATE OR REPLACE TRANSIENT TABLE {SNOWFLAKE_SAMPLE_TABLE} (name VARCHAR(250), id INT);"
SQL_INSERT_STATEMENT = f"INSERT INTO {SNOWFLAKE_SAMPLE_TABLE} VALUES ('name', %(id)s)"
SQL_LIST = [SQL_INSERT_STATEMENT % {"id": n} for n in range(0, 10)]
SNOWFLAKE_SLACK_SQL = f"SELECT name, id FROM {SNOWFLAKE_SAMPLE_TABLE} LIMIT 10;"
SNOWFLAKE_SLACK_MESSAGE = "Results in an ASCII table:\n```{{ results_df | tabulate(tablefmt='pretty', headers='keys') }}```"

default_args = {
    "owner": "airflow",
}

dag = DAG(
    "example_snowflake",
    default_args=default_args,
    start_date=days_ago(2),
    tags=["example"],
)

# [START howto_operator_snowflake]

snowflake_op_sql_str = SnowflakeOperator(
    task_id="snowflake_op_sql_str",
    dag=dag,
    snowflake_conn_id=SNOWFLAKE_CONN_ID,
    sql=CREATE_TABLE_SQL_STRING,
    warehouse=SNOWFLAKE_WAREHOUSE,
    database=SNOWFLAKE_DATABASE,
    schema=SNOWFLAKE_SCHEMA,
    role=SNOWFLAKE_ROLE,
)

snowflake_op_with_params = SnowflakeOperator(
    task_id="snowflake_op_with_params",
    dag=dag,
    snowflake_conn_id=SNOWFLAKE_CONN_ID,
    sql=SQL_INSERT_STATEMENT,
    parameters={"id": 56},
    warehouse=SNOWFLAKE_WAREHOUSE,
    database=SNOWFLAKE_DATABASE,
    schema=SNOWFLAKE_SCHEMA,
    role=SNOWFLAKE_ROLE,
)

snowflake_op_sql_list = SnowflakeOperator(
    task_id="snowflake_op_sql_list",
    dag=dag,
    snowflake_conn_id=SNOWFLAKE_CONN_ID,
    sql=SQL_LIST,
)

snowflake_op_template_file = SnowflakeOperator(
    task_id="snowflake_op_template_file",
    dag=dag,
    snowflake_conn_id=SNOWFLAKE_CONN_ID,
    sql="/path/to/sql/<filename>.sql",
)

# [END howto_operator_snowflake]

# [START howto_operator_s3_to_snowflake]

copy_into_table = S3ToSnowflakeOperator(
    task_id="copy_into_table",
    snowflake_conn_id=SNOWFLAKE_CONN_ID,
    s3_keys=[S3_FILE_PATH],
    table=SNOWFLAKE_SAMPLE_TABLE,
    schema=SNOWFLAKE_SCHEMA,
    stage=SNOWFLAKE_STAGE,
    file_format="(type = 'CSV',field_delimiter = ';')",
    dag=dag,
)

# [END howto_operator_s3_to_snowflake]

# [START howto_operator_snowflake_to_slack]

slack_report = SnowflakeToSlackOperator(
    task_id="slack_report",
    sql=SNOWFLAKE_SLACK_SQL,
    slack_message=SNOWFLAKE_SLACK_MESSAGE,
    snowflake_conn_id=SNOWFLAKE_CONN_ID,
    slack_conn_id=SLACK_CONN_ID,
    dag=dag,
)

# [END howto_operator_snowflake_to_slack]

snowflake_op_sql_str >> [
    snowflake_op_with_params,
    snowflake_op_sql_list,
    snowflake_op_template_file,
    copy_into_table,
] >> slack_report