PiggyBank/piggybank/cli/put.py

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

from re import split, search
from sys import argv, stderr

from piggybank.configuration import Configuration
from piggybank.cli import complement_list_of_coins, handle_default_arguments
from piggybank.currencies import CURRENCIES, BaseCurrencyError
from piggybank.piggybank import PiggyBank

__all__ = ["main"]


USAGE_PUT = "Usage: piggybank-put [-r|--reversed] COINS in FILE of CURRENCY\n" \
    "Put a set of coins in a piggybank. Set a currency of a new one.\n\n" \
    "-r, --reversed -- use reversed order of COINS (from greater to least);\n" \
    "COINS          -- array of comma or whitespace separated coins;\n" \
    "in FILE        -- .pb file name of your piggybank;\n" \
    "of CURRENCY    -- set a currency for a new piggybank.\n"


def parse_put_arguments(args):
    r = r"(?P<reversed>-r|--reversed)? ?(?P<coins>[\d ,]+) in (?P<file>\S+)(?= of (?P<currency>\S+))?"
    argd = search(r, args)
    if not argd is None:
        argd = argd.groupdict()
        return {
            "coins": list(map(int, split(r"\D",argd["coins"]))),
            "file": argd["file"],
            "currency":  Configuration()["default-currency"] \
                if argd["currency"] is None else argd["currency"],
            "reversed": not argd["reversed"] is None }
    return None


def main() -> None:
    handle_default_arguments(' '.join(argv[1:]), lambda: print(USAGE_PUT))
    args = parse_put_arguments(' '.join(argv[1:]))

    if args is None:
        print(USAGE_PUT)
        exit()

    try:
        try:
            piggybank = PiggyBank.from_file(args["file"])
        except FileNotFoundError:
            currency = Configuration()["default-currency"] \
                if args["currency"] is None else args["currency"]
            piggybank = PiggyBank(currency)
        coins = complement_list_of_coins(args["coins"], piggybank.currency,
                                            args["reversed"])
        piggybank.transact(coins)
        piggybank.save(args["file"])
    except BaseCurrencyError as err:
        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)