PiggyBank/piggybank/__main__.py

"""CLI"""

from re import search, split
from sys import argv, stderr
from os.path import exists
from typing import List

from piggybank import VERSION, CURRENCIES
from piggybank.configuration import Configuration, DEFAULT_CONFIGURATION_FILE
from piggybank.currency import Currency, BaseCurrencyError
from piggybank.piggybank import PiggyBank
from piggybank.transaction import sum_transactions, TYPE_INCOME, TYPE_OUTCOME

__all__ = ["main"]


USAGE = \
"""Usage: piggybank [OPTIONS] (COINS in FILE [of CURRENCY] | COINS from FILE
 | show FILE [with t(ransactions)])

Options:
\t-h,--help                   -- print this help;
\t-v,--version                -- print program version;
\t-L,--list-currencies        -- list supported currencies and a default one;
\t-r,--reversed               -- change COINS' complementation from left to right.
\t                               (e.g. 4 5 -> 0 0 0 0 4 5 by default; 4 5 0 0 0 0
\t                               with this flag).

There are three actions available: put, take and show.

Put:  piggybank [-r|--reversed] COINS in FILE [of CURRENCY]
Take: piggybank [-r|--reversed] COINS from FILE
Show: piggybank show FILE [with t(ransactions)]

Arguments:
\tCOINS               -- a set of comma or whitespace separated coin counts;
\tFILE                -- a filename of a piggy bank;
\tof CURRENCY         -- set a partcular currency for a piggy bank;
\twith t(ransactions) -- print a table of transactions as well.
"""


def parse_common_arguments(args: str) -> dict:
    r = r"(?P<help>-h|--help)|(?P<version>-v|--version)" \
        r"|(?P<list_currencies>-L|--list-currencies)"
    argd = search(r, args)
    if not argd is None:
        argd = argd.groupdict()
        return {
            "help": not argd["help"] is None,
            "version": not argd["version"] is None,
            "list-currencies": not argd["list_currencies"] is None }
    return None

def parse_arguments(args: str) -> dict:
    r = r"((?P<reversed>-r|--reversed)? ?(?P<coins>[\d, ]+)?)" \
        r" ?(?P<action>in|from|show) (?P<file>\S+)" \
        r" ?(?=(?=of (?P<currency>\S+)" \
        r"|(?=with (?P<transactions>t|transactions))))?"
    argd = search(r, args)
    if not argd is None:
        argd = argd.groupdict()
        return {
            "reversed": not argd["reversed"] is None,
            "coins": list(map(int, split(r"\D", argd["coins"].strip()))) \
                if not argd["coins"] is None else None,
            "action": argd["action"],
            "file": argd["file"],
            "currency": argd["currency"],
            "show-transactions": argd["transactions"] }
    return None


def print_transactions(pb: PiggyBank) -> None:
    currency = CURRENCIES[pb.currency]
    names = (currency.currency_symbol.format(n//100) if n >= 100 \
             else currency.fraction_symbol.format(n) \
             for n in currency.face_values)
    def print_separator(l: str, m: str, r: str):
        print(f"{l}{'━'*21}{m}{'━'*5}{m}{m.join(['━'*12]*len(currency))}{r}")

    print_separator("┏", "┳", "┓")
    print(f"┃{'Timestamp':^21}┃ I/O ┃" \
          f"{'┃'.join(f'{n:^12}' for n in names)}┃")
    print_separator("┣", "╋", "┫")
    for t in pb.transactions:
        print(f"┃ {t.timestamp.replace('T', ' ')} "
              f"┃{t.direction:^5}"
              f"┃{'┃'.join(f'{c:^12}' for c in t.coins)}┃")
    print_separator("┗", "┻", "┛")

def print_summary(pb: PiggyBank) -> None:
    currency = CURRENCIES[pb.currency]
    names = (currency.currency_symbol.format(n//100) if n >= 100 \
             else currency.fraction_symbol.format(n) \
             for n in currency.face_values)
    def print_separator(l: str, lm: str, rm: str, r:str):
        print(f"{l}{'━'*27}{lm}{rm.join(['━'*12]*len(currency))}{r}")

    print_separator("┏", "┳", "┳", "┓")
    print(f"┃{currency.name:^27}┃{'┃'.join(f'{n:^12}' for n in names)}┃")
    print_separator("┣", "╋", "╋", "┫")
    s = sum_transactions(pb.transactions)
    print(f"┃{'Counts':^27}┃{'┃'.join(f'{c:^12}' for c in s)}┃")
    print_separator("┣", "╋", "╋", "┫")
    s = currency * s
    print(f"┃{'Sums':^27}┃{'┃'.join(f'{c/100:^12.2f}' for c in s)}┃")
    print_separator("┣", "╋", "┻", "┫")
    s = sum(s)
    print(f"┃{'Total':^27}┃{s/100:^{12*len(currency)+len(currency)-1}.2f}┃")
    print_separator("┗", "┻", "━", "┛")


def print_supported_currencies() -> None:
    """Print a list of supported currencies."""
    print("Supported currencies are:")
    for cur in CURRENCIES.keys():
        print(f"  {cur:^4} ┃ {CURRENCIES[cur].name:^31}")
    print("Default currency is", Configuration()["default-currency"])

def load_currencies() -> None:
    """Load currencies defined in a configuration file."""
    if not "currency" in Configuration().items:
        return
    for iso, cur in Configuration()["currency"].items():
        CURRENCIES[iso.upper()] = Currency.from_string(cur)

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


def main():
    cargs = parse_common_arguments(' '.join(argv))
    if not cargs is None:
        if cargs["help"]:
            print(USAGE)
            exit()
        elif cargs["version"]:
            print(VERSION)
            exit()
        elif cargs["list-currencies"]:
            load_currencies()
            print_supported_currencies()
            exit()

    args = parse_arguments(' '.join(argv))
    if not args:
        print(USAGE)
        exit()

    try:
        if not exists(DEFAULT_CONFIGURATION_FILE):
            Configuration.write_default_to_file(DEFAULT_CONFIGURATION_FILE)
        load_currencies()

        try:
            pb = PiggyBank.from_file(args["file"])
        except FileNotFoundError:
            if args["action"] == 'in':
                currency = Configuration()["default-currency"] \
                        if not args["currency"] else args["currency"]
                pb = PiggyBank(currency)
            else:
                raise FileNotFoundError(f"{args['file']} is missing.")

        if args["action"] in ["in", "from"]:
            coins = complement_list_of_coins(args["coins"], pb.currency,
                                                args["reversed"])
            pb.transact(coins, TYPE_INCOME if args["action"] == "in" \
                        else TYPE_OUTCOME)
            pb.save(args["file"])
        elif args["action"] == "show":
            print_summary(pb)
            if args["show-transactions"]:
                print_transactions(pb)
    except BaseCurrencyError as err:
        print(f"{type(err).__name__}:", err, file=stderr)
    except FileNotFoundError 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)

if __name__ == "__main__":
    main()