import os
from datetime import timedelta

import pendulum
import requests
from airflow.decorators import dag
from airflow.decorators import task
from airflow.providers.amazon.aws.hooks.s3 import S3Hook

S3_CONN_ID = os.getenv("S3_CONN_ID", "s3_conn")
EXECUTION_TIMEOUT = int(os.getenv("EXECUTION_TIMEOUT", 6))

default_args = {
    "execution_timeout": timedelta(hours=EXECUTION_TIMEOUT),
    "retries": int(os.getenv("DEFAULT_TASK_RETRIES", 1)),
    "retry_delay": timedelta(seconds=int(os.getenv("DEFAULT_RETRY_DELAY_SECONDS", 60))),
}


@dag(
    start_date=pendulum.datetime(2021, 1, 1, tz="UTC"),
    schedule=None,
    catchup=False,
    default_args=default_args,
    params={
        "url": "File to download",
        "dst_key": "key containing the file",
        "dst_bucket": "bucket that will contain file"
    },
    tags=["s3"],
)
def download_to_s3():
    @task
    def download(**context):
        hook = S3Hook(S3_CONN_ID, transfer_config_args={'use_threads': False})
        with requests.get(context["params"]["url"], stream=True) as r:
            r.raise_for_status()
            hook.load_file_obj(r.raw, context["params"]["dst_key"], bucket_name=context["params"]["dst_bucket"], replace=True, encrypt=False)

    download()


download_to_s3()