new.py

import os
import re
from pathlib import Path
from shutil import copyfile


BOILERPLATE_DIRECTORY = Path("./bp/")
DAY_PATTERN = re.compile(r"(\d{4}).(\d{2}).?(\d)?")


class BoilerplateException(Exception):
    pass


def create_day_directory(year, day):
    directory = Path() / year / day
    if not directory.exists():
        os.makedirs(directory)
    return directory


def create_source_file(folder, lang, part="1", force=False):
    if part != "1":
        boilerplate = folder / f"p{int(part) - 1}.{lang}"
    else:
        boilerplate = BOILERPLATE_DIRECTORY / f"bp.{lang}"

    destination = folder / f"p{part}.{lang}"

    if destination.exists() and not force:
        raise BoilerplateException(
            "Can not copy to a file that already exists: {}".format(destination)
        )
    elif not boilerplate.exists():
        raise BoilerplateException("No .{} boilerplate file exists".format(lang))

    copyfile(boilerplate, destination)


def create_empty_files(folder, input=False):
    if input:
        (folder / "input.txt").touch()
    (folder / "challenge.txt").touch()


def main(args):
    year, day, part = DAY_PATTERN.match(args.day).groups()
    dest_folder = create_day_directory(year, day)
    create_source_file(dest_folder, args.lang, part or "1", args.force)
    create_empty_files(dest_folder, args.input)


if __name__ == "__main__":
    import argparse

    parser = argparse.ArgumentParser(description="Create a new empty day.")
    parser.add_argument("day", help='Day to make a new directory for; e.g. "2020.06"')
    parser.add_argument("lang", help="Corresponds to a file extension in ./bp/")
    parser.add_argument(
        "-i", "--input", action="store_true", help="Add empty input file too"
    )
    parser.add_argument(
        "-f", "--force", action="store_true", help="Force copying of boilerplate file"
    )
    args = parser.parse_args()

    try:
        main(args)
    except BoilerplateException as e:
        print("Error:", e)