"""Interface to the ows-accounting microservice."""


from owsrequest import request

from flows import config
from .exceptions import OWSError


ACCOUNTING_PERIOD_ENDPOINT = '/accounting_period'
ACCOUNTING_SERVICE = 'ows-accounting'


def get_accounting_period(correlation_id=None):
    """Get active accounting period ID (APID).

    Fetch APID with a GET call to ows-accounting
    (see: GET /accounting_period endpoint).

    Args:
        correlation_id (str): correlation id.

    Raises:
        OWSError: if an error occurs during the OWS call.

    Returns:
        str: ID of active accounting period.
    """
    domain = ACCOUNTING_SERVICE
    resource = ACCOUNTING_PERIOD_ENDPOINT
    ows_response = request.process(
        application=config.SERVICE_NAME, environment=config.ENVIRONMENT,
        method='GET', service_name=domain, path=resource,
        correlation_id=correlation_id)

    if ows_response.status_code is 200:
        return ows_response.json()['accounting_period']
    else:
        raise OWSError(
            """An error occurred while requesting accounting period
            from {ows_service}"""
            '@ {url}: {status_code} {reason}.'.format(
                ows_service=ACCOUNTING_SERVICE,
                url=ows_response.url,
                status_code=ows_response.status_code,
                reason=ows_response.reason))