import argparse

default_server = 'www-net-devel.scc.kit.edu'
default_api_version = '3.0'


class ArgumentParser(argparse.ArgumentParser):
    """Argument parser with default common arguments for NetDB-api cli
    tools. Includes default values."""
    def __init__(self, formatter_class=argparse.ArgumentDefaultsHelpFormatter,
                 **kwargs):
        super(ArgumentParser, self).__init__(formatter_class=formatter_class,
                                             **kwargs)
        self.add_argument('--token', '-t',
                          help='user API token', required=True)
        self.add_argument('--server', '-s', default=default_server,
                          help='webapi server')
        self.add_argument('--api-version', default=default_api_version,
                          help='webapi version')

    def parse_args(self, args=None, namespace=None):
        args = super(ArgumentParser, self).parse_args(args, namespace)
        return args


def dict_by_value_of_list(array, value):
    """Mapping function to convert list of dicts to an dict with value as key for each dict. (1 to 1 Mapping)
    Returns an generator object."""
    return ((item[value], item) for item in array)


def dict_of_lists_by_value_of_list(array, value):
    """Mapping function to convert list of dicts to an dict with values as key for each lists. (1 to n Mapping)
    Returns an generator object."""
    res = {}
    for item in array:
        if not item[value] in res:
            res[item[value]] = []
        res[item[value]].append(item)
    for key, value in res.items():
        yield key, value