#!/usr/bin/env python3

"""
Encode/decode HTML entities in stdin or given file(s).
"""

import argparse
import fileinput
import html
from html.entities import entitydefs

ENTITIES = {value: key for key, value in entitydefs.items()}


def encode(text):
    t = ""
    for c in text:
        if c in ENTITIES:
            t += "&" + ENTITIES[c] + ";"
        else:
            t += c
    return t

def decode(text):
    return html.unescape(text)


if __name__ == '__main__':
    opts = argparse.ArgumentParser(description="Encodes (or decodes) HTML entities in text.")
    opts.add_argument('file', type=str, nargs="*", help="File to encode/decode")
    opts.add_argument('-d', '--decode', action='store_true', help="Decode the given files/input")
    args = opts.parse_args()

    text = [line for line in fileinput.input(args.file)]
    action = decode if args.decode else encode
    print(action("\n".join(text).strip()))