#!/usr/bin/env python3

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

import getopt
import sys
import os
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)

def usage():
    # TODO Improve this
    print("Usage: {} [-edh] file1[ file2[ ...]]".format(os.path.basename(sys.argv[0])))


if __name__ == '__main__':
    COMMANDS = {
        "-e": encode,
        "-d": decode
    }

    try:
        optlist, args = getopt.getopt(sys.argv[1:], 'edh')
        sys.argv = [sys.argv[0]] + args
    except getopt.GetoptError as err:
        print(err)
        sys.exit(1)

    action = encode
    for o, a in optlist:
        if o in COMMANDS:
            action = COMMANDS[o]
        elif o == '-h':
            usage()
            sys.exit()
        else:
            assert False, "unhandled option"

    input = "\n".join([line for line in fileinput.input()]).strip()
    print(action(input))