"""Utility functions."""

from argparse import ArgumentParser
from typing import List

from piggybank import __version__, __copyright__, __license__
from piggybank.currencies import CURRENCIES, DEFAULT_CURRENCY


__all__ = ["add_common_arguments_to_parser", "complement_array_of_coins"]


def add_common_arguments_to_parser(parser: ArgumentParser,
                                   include_reverse_flag: bool = True) -> None:
    """Extends ArgumentParser with a common set of arguments that are shared
    amongst all parsers in CLI module."""
    parser.add_argument("-v", "--version", action="store_true",
                        help="show program's version and license and exit")
    parser.add_argument("--list-currencies", action="store_true",
                        help="list all supported currencies and exit")

    if include_reverse_flag:
        parser.add_argument("-r", "--reverse", action="store_true",
                            help="reverse a set of coins so incomplete set"
                            "fills with zeros from right. E.g. '8 9' will be"
                            "interpreted as '8 9 0 0 0 0' instead of"
                            "'0 0 0 0 8 9'")


def complement_array_of_coins(coins: List[int], currency: str,
                              _reversed: bool = False) -> List[int]:
    """Complements array of coins up to the count of currency's coins."""
    offset_array = [0] * (CURRENCIES[currency]["count"] - len(coins))
    return offset_array + coins if not _reversed else coins + offset_array