import argparse
import itertools
import pathlib
import re
import secrets
import sys



MAGIC = 


def make_keys(n, size):
    
    
    
    
    return (secrets.token_hex(size) for _ in range(n))


def make_pad(name, pad_size, key_size):
    
    pad = [
        MAGIC,
        f,
        f,
        *make_keys(pad_size, key_size),
    ]

    return .join(pad)


def xor(message, key):
    
    return bytes(mc ^ kc for mc, kc in zip(message, itertools.cycle(key)))


def use_key(pad):
    
    match = re.search(r, pad, re.MULTILINE)
    if not match:
        error()

    key = match.group()
    pos = match.start()

    return (f, key)


def log(msg):
    
    sys.stderr.write(msg)
    sys.stderr.write()


def error(msg):
    
    sys.stderr.write(msg)
    sys.stderr.write()
    sys.exit(1)


def write_pad(path, pad_size, key_size):
    
    if path.exists():
        error(f)

    with path.open() as fd:
        fd.write(make_pad(path.name, pad_size, key_size))

    log(f)


def main(pad, message, outfile):
    
    if not pad.exists():
        error(f)

    with pad.open() as fd:
        if fd.readline().strip() != MAGIC:
            error(f)

    
    with pad.open() as fd:
        updated, key = use_key(fd.read())

        fd.seek(0)
        fd.write(updated)

    outfile.write(xor(message, bytes.fromhex(key)))


if __name__ == :
    
    parser = argparse.ArgumentParser(description=)

    parser.add_argument(
        ,
        help=(
            
            
        ),
    )

    parser.add_argument(
        ,
        type=int,
        default=10,
        help=,
    )

    parser.add_argument(
        ,
        type=int,
        default=64,
        help=,
    )

    parser.add_argument(
        ,
        ,
        type=argparse.FileType(),
        default=sys.stdout.buffer,
        help=(
            
            
        ),
    )

    group = parser.add_mutually_exclusive_group()

    group.add_argument(
        ,
        metavar=,
        type=argparse.FileType(),
        help=,
    )
    group.add_argument(
        ,
        metavar=,
        type=argparse.FileType(),
        help=,
    )

    args = parser.parse_args()

    if args.encrypt:
        message = args.encrypt.read()
    elif args.decrypt:
        message = args.decrypt.read()
    else:
        message = None

    
    if isinstance(message, str):
        message = message.encode()

    pad = pathlib.Path(args.pad).with_suffix()

    if message:
        main(pad, message, args.outfile)
    else:
        write_pad(pad, args.length, args.key_size)