"""Boto3 S3 connector."""

from functools import cache

import boto3
from botocore.exceptions import ClientError

from deliveryhistory import config


@cache
def get_s3_client():
    """Connect to S3.

    Returns:
        botocore.client.S3: client object providing access to S3.

    """
    return boto3.session.Session().client('s3', region_name=config.AWS_REGION)


def get_object_body(bucket, key):
    """Download the body of an S3 object.

    Args:
        bucket (str): the S3 bucket name
        key (str): the S3 object key

    Returns:
        bytes: the object body, or None if the object does not exist

    """
    try:
        result = get_s3_client().get_object(Bucket=bucket, Key=key)
    except ClientError:
        return None
    return result['Body'].read()