import xmltodict

from openml._api_calls import _perform_api_call


def _check_flow_exists(name, version):
    """Retrieves the flow id of the flow uniquely identified by name+version.

    Parameter
    ---------
    name : string
        Name of the flow
    version : string
        Version information associated with flow.

    Returns
    -------
    flow_exist : int
        Flow id or -1 if the flow doesn't exist.

    Notes
    -----
    see https://www.openml.org/api_docs/#!/flow/get_flow_exists_name_version
    """
    if not (type(name) is str and len(name) > 0):
        raise ValueError('Argument \'name\' should be a non-empty string')
    if not (type(version) is str and len(version) > 0):
        raise ValueError('Argument \'version\' should be a non-empty string')

    return_code, xml_response = _perform_api_call(
        "flow/exists/%s/%s" % (name, version))
    # TODO check with latest version of code if this raises an exception
    if return_code != 200:
        # fixme raise appropriate error
        raise ValueError("api call failed: %s" % xml_response)
    xml_dict = xmltodict.parse(xml_response)
    flow_id = xml_dict['oml:flow_exists']['oml:id']
    return return_code, xml_response, flow_id