"""Amazon S3 connector."""
import boto3
from botocore.exceptions import ClientError
from oto import response

from masters_registry import config
from masters_registry.connectors import sentry
from masters_registry.constant import error


client = boto3.client('s3')


def get_file_url(file_key, expires_in=86400):
    """Generate download url for provided file in s3 bucket.

    Args:
        file_key (str): path to file for which url should be generated.
        expires_in (int): lifetime of url. Default is 1 day.

    Returns:
        Response: Response with url in message or with errors.
    """
    bucket_name = config.REPORTS_BUCKET_NAME
    if not check_if_file_exists(file_key):
        if sentry.sentry_client:
            sentry.sentry_client.captureException()
        message = error.S3_FILE_NOT_FOUND .format(
            key=file_key, bucket=bucket_name)
        return response.create_not_found_response(message)

    url = client.generate_presigned_url(
        'get_object',
        Params={'Bucket': bucket_name, 'Key': file_key},
        ExpiresIn=expires_in
    )
    return response.Response(url)


def upload_file_object(file_key, file_data):
    """Upload file obejct to S3 .

    Args:
        file_key (str): key of a file that should be uploaded to s3 bucket.
        file_data (StringIO): file content
    """
    client.upload_fileobj(
        file_data, config.REPORTS_BUCKET_NAME, file_key)


def check_if_file_exists(file_key):
    """Checks if file exists in s3 bucket.

    Args:
        file_key (str): path to a file

    Returns:
        bool: Whether file exists
    """
    try:
        client.head_object(
            Bucket=config.REPORTS_BUCKET_NAME, Key=file_key)
    except ClientError as error:
        return int(error.response['Error']['Code']) != 404
    return True