"""S3 common functions."""

import boto3
import botocore

from src import config


client = boto3.client('s3')
resource = boto3.resource('s3')


def head_object(bucket, key):
    """Get object info or None if object doesn't exist."""
    try:
        return client.head_object(
            Bucket=bucket,
            Key=key,
            ExpectedBucketOwner=config.EXPECTED_BUCKET_OWNER
        )
    except botocore.exceptions.ClientError as e:
        if e.response['Error']['Code'] == '404':
            return None
        raise