"""CLI: Show summarised information on a piggybank."""

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

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

__all__ = ["main"]

DEFAULT_COIN_CENTERING: int = 10


def print_summary(piggybank: PiggyBank,
                  centering: int = DEFAULT_COIN_CENTERING) -> None:
    """Print summarised information on a piggy bank.
    Prints a table with totals of how much coins of which face value are in a
    piggy bank; A total sum converted to its currency for each face value and
    overall total sum in a currency of a piggy bank."""
    def print_separator(left="┣", lmiddle="╋", rmiddle="╋", right="┫"):
        line = rmiddle.join('━' * centering
                            for _ in
                            range(CURRENCIES[piggybank.currency]['count']))
        print(f"{left}{'━'*27}{lmiddle}{line}{right}")

    cc, cs, ct = piggybank.count, piggybank.sum, piggybank.total

    cline = "┃".join([f'{l:^{centering}}'
                     for l in CURRENCIES[piggybank.currency]["names"]])
    cline_len = len(cline)

    print_separator(left="┏", lmiddle="┳", rmiddle="━", right="┓")
    print(f"┃{'currency':^27}┃"
          f"{CURRENCIES[piggybank.currency]['name']:^{cline_len}}┃")
    print_separator(rmiddle="┳")
    print(f"┃{'face values':^27}┃{cline}┃")
    print_separator()
    print(f"┃{'amount':^27}┃{'┃'.join([f'{c:^{centering}}' for c in cc])}┃")
    print_separator()
    print(f"┃{'sum':^27}┃"
          f"{'┃'.join(['{:^{}.2f}'.format(c / 100, centering) for c in cs])}┃")
    print_separator(rmiddle="┻")
    print(f"┃{'total':^27}┃{'{:^{}.2f}'.format(ct / 100, cline_len)}┃")
    print_separator(left="┗", lmiddle="┻", rmiddle="━", right="┛")


def print_transactions(piggybank, centering=DEFAULT_COIN_CENTERING):
    """Print a list of all transactions stored in a piggy bank."""
    def print_separator(left="┏", middle="┳", right="┓"):
        line = middle.join('━' * centering
                           for _ in
                           range(CURRENCIES[piggybank.currency]['count']))
        print(f"{left}━━━━━━━━━━━━━━━━━━━━━{middle}━━━━━{middle}{line}{right}")

    cline = "┃".join([f'{l:^{centering}}'
                     for l in CURRENCIES[piggybank.currency]["names"]])

    print_separator()
    print(f"┃{'Timestamp':^21}┃ I/O ┃{cline}┃")
    print_separator("┣", "╋", "┫")
    for tr in piggybank.transactions:
        coin_line = "┃".join([f'{c:^{centering}}' for c in tr.coins])
        ts = tr.timestamp.replace("T", " ")
        print(f"┃ {ts} ┃{tr.direction:^5}┃{coin_line}┃")
    print_separator("┗", "┻", "┛")


def main():
    """An entry point for a show command."""
    parser = ArgumentParser(prog="piggybank-show",
                            description="Show information on 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("-t", "--transactions", action="store_true",
                        help="print a list of transactions as well")

    parser.add_argument("-m", "--merge", action="append",
                        type=str, metavar="FILE",
                        help="merge multiple files to show how much do you"
                        "have across them. They all should be of same currency")

    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")

    args = parser.parse_args()

    if args.version:
        print_program_version()
        exit()

    if args.list_currencies:
        print_supported_currencies()
        exit()

    try:
        piggybank = PiggyBank.from_file(args.file)
        if args.merge:
            for _file in args.merge:
                merge_piggybank = PiggyBank.from_file(_file)
                piggybank += merge_piggybank
                print(_file)
        print_summary(piggybank)
        if args.transactions:
            print_transactions(piggybank)
    except BaseCurrencyError as err:
        print(f"{type(err).__name__}:", err, file=stderr)
    except FileNotFoundError as err:
        print(f"{type(err).__name__}:", f"{err} doesn't exist.", file=stderr)
    except Exception as err:
        print(f"Something went exceptionally wrong. Error:",
              f"{type(err).__name__}:", err, file=stderr)