import os
import tarfile
from datetime import timedelta

import pendulum
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={
        "src_key": "File to untar",
        "src_bucket": "bucket containing the zip file",
        "dst_key_prefix": "",
        "dst_bucket": "bucket that will contain unzipped files"
    },
    tags=["s3"],
)
def s3_untar():
    @task
    def untar(**context):
        hook = S3Hook(S3_CONN_ID, transfer_config_args={'use_threads': False})
        s3_obj = hook.get_key(context["params"]["src_key"], bucket_name=context["params"]["src_bucket"])
        with tarfile.open(fileobj=s3_obj.get()["Body"], mode='r|') as tar:
            for member in tar:
                dst_key = context["params"]["dst_key_prefix"] + "/" + member.name
                dst_key = os.path.normpath(dst_key)
                # Ignore directories, links, devices, fifos, etc.
                if not member.isfile():
                    print(f"Skipping {member.name} to {dst_key}")
                    continue
                print(f"Extracting {member.name} to {dst_key}")
                #hook.load_file_obj(tar.extractfile(member),
                #                   dst_key,
                #                   context["params"]["dst_bucket"],
                #                   replace=True)

    untar()


s3_untar()