"""S3 common functions."""

import boto3
import botocore

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


def upload_key(bucket, key, data):
    """Upload S3 key.

    Args:
        bucket (str): target S3 bucket.
        key (str): target S3 key.
        data (bytes): key content.
    """
    client.put_object(Bucket=bucket, Key=key, Body=data)


def copy_key(source_bucket, source_key, new_bucket, new_key):
    """Copy S3 key.

    Args:
        source_bucket (str): source S3 bucket.
        source_key (str): source S3 key.
        source_bucket (str): new S3 bucket.
        source_key (str): new S3 key.
    """
    bucket = resource.Bucket(new_bucket)
    bucket.copy({'Bucket': source_bucket, 'Key': source_key}, new_key)


def delete_key(bucket, key):
    """Delete S3 key.

    Args:
        bucket (str): target S3 bucket.
        key (str): target S3 key.
    """
    client.delete_object(Bucket=bucket, Key=key)


def key_exists(bucket, key):
    """Check if S3 key exists.

    Args:
        bucket (str): target S3 bucket.
        key (str): target S3 key.
    """
    try:
        client.head_object(Bucket=bucket, Key=key)
    except botocore.exceptions.ClientError as e:
        if e.response['Error']['Code'] == '404':
            return False
        else:
            raise
    else:
        return True