PiggyBank/piggybank/cli/put.py

"""CLI: Put a set of coins into a piggy bank."""

from argparse import ArgumentParser
from os.path import exists
from sys import exit, stderr

from piggybank import print_program_version
from piggybank.cli import EPILOGUE, complement_array_of_coins
from piggybank.currencies import CURRENCIES, DEFAULT_CURRENCY, \
    BaseCurrencyError, print_supported_currencies
from piggybank.piggybank import PiggyBank

__all__ = ["main"]


def main() -> None:
    """An entry point for a put command."""
    parser = ArgumentParser(prog="piggybank-put",
                            description="Add a set of coins to a piggy bank.",
                            epilog=EPILOGUE)
    parser.add_argument("file", type=str,
                        help="a piggy bank file name. Missing .pb extension"
                        "will be added")
    parser.add_argument("coins", type=int, nargs="+", metavar="COIN",
                        help="a set of coins to add. A new file will be"
                        "created if it doesn't exist")

    parser.add_argument("-c", "--currency", type=str, default=DEFAULT_CURRENCY,
                        help="set currency of a piggy bank. Not applicable to"
                        "an existing one")

    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")

    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'")

    args = parser.parse_args()

    if args.version:
        print_program_version()
        exit()

    if args.list_currencies:
        print_supported_currencies()
        exit()

    try:
        try:
            piggybank = PiggyBank.from_file(args.file)
        except FileNotFoundError:
            piggybank = PiggyBank(args.currency)
        coins = complement_array_of_coins(args.coins, piggybank.currency,
                                          args.reverse)
        piggybank.transact(coins)
        piggybank.save(args.file)
    except BaseCurrencyError:
        print(f"{type(err).__name__}:", err, file=stderr)
    except ValueError as err:
        print(f"{type(err).__name__}:", err, file=stderr)
    except Exception as err:
        print(f"Something went exceptionally wrong. Error:",
              f"{type(err).__name__}:", err, file=stderr)