convert RequestPolicy's `*.properties` I18n files of the legacy xpcom-based firefox extension to WebExtension-type `message.json` files

convert.py

#!/usr/bin/python3

# source: https://github.com/RequestPolicyContinued/requestpolicy/issues/876

import os
import re

default_locale = 'en-US'
locales = [
    'de', 'en-US', 'eo', 'es-ES', 'es-MX', 'eu', 'fr', 'it', 'ja', 'ko-KR',
    'lv-LV', 'nl', 'pl', 'pt-BR', 'ru-RU', 'sk-SK', 'sv-SE', 'tr', 'uk-UA',
    'zh-CN', 'zh-TW',
]

TAB = '  '


def src_path(locale):
    return "src/locale/{}/requestpolicy.properties".format(locale)


def dest_path(locale):
    locale = locale.replace('-', '_')
    return "src/conditional/webextension/_locales/{}/messages.json".format(locale)


def addon_description(locale, list_):
    with open('src/conditional/legacy/install.rdf', 'r') as s:
        match = re.search(r'''
            \s*  <em:localized>
            \s*    <Description>
            \s*      <em:locale>{}</em:locale>
            \s*      <em:name>([^<]*)</em:name>
            \s*      <em:description>([^<]*)</em:description>
            \s*    </Description>
            \s*  </em:localized>
            \s*
        '''.format(locale), s.read().replace('\n', ' '), re.VERBOSE)
        if match is not None:
            list_.insert(0, 'extensionName=' + match.group(1))
            list_.insert(1, 'extensionDescription=' + match.group(2))


def map_str(str_):
    return (
        str_
        .replace('%S', '$1')
        .replace('%1$S', '$1')
        .replace('%2$S', '$2')
        .replace(r'\"', r'"')
        .replace('"', r'\"')
    )


def get_list(locale):
    l = []
    with open(src_path(locale), "r") as s:
        l = s.read().split("\n")
    addon_description(locale, l)
    l = [map_str(s).split('=') for s in l if s != '']
    return l


def get_dict(locale):
    l = get_list(locale)
    d = {}
    for [key, value] in l:
        d[key] = value
    return d


def reduce_dict(d, d_default):
    for key in list(d.keys()):
        assert key in d_default
        if d[key] == d_default[key]:
            del d[key]


def key_order():
    l = get_list(default_locale)
    for [key, _] in l:
        yield key


def get_entries(d, d_default):
    for key in key_order():
        if key not in d:
            continue
        tvalue = d[key]
        dvalue = d_default[key]
        entry = ""
        entry += (TAB*1) + "\"" + key + "\": {\n"
        entry += (TAB*2) + "\"message\": \"" + tvalue + "\",\n"
        entry += (TAB*2) + "\"description\": \"" + dvalue + "\"\n"
        entry += TAB + "}"
        yield entry


def main():
    print("Converting from .properties to messages.json...")

    d_default = get_dict(default_locale)

    for locale in locales:
        print(locale)

        d = get_dict(locale)
        if locale != default_locale:
            reduce_dict(d, d_default)

        destfile_path = dest_path(locale)
        destdir_path = os.path.dirname(destfile_path)

        if not os.path.exists(destdir_path):
            os.makedirs(destdir_path)

        # Write messages.json file
        with open(destfile_path, "w") as f:
            f.write("{\n")
            entries = list(get_entries(d, d_default))
            f.write(",\n\n".join(entries))
            f.write("\n}\n")

    print("Done.")

main()