import fbchat

# Change this to your group id
old_thread_id = "1234567890"

# Change these to match your liking
old_color = fbchat.ThreadColor.MESSENGER_BLUE
old_emoji = "👍"
old_title = "Old group chat name"
old_nicknames = {
    "12345678901": "User nr. 1's nickname",
    "12345678902": "User nr. 2's nickname",
    "12345678903": "User nr. 3's nickname",
    "12345678904": "User nr. 4's nickname",
}


class KeepBot(fbchat.Client):
    def on_color_change(self, author_id, new_color, thread_id, thread_type, **kwargs):
        if old_thread_id == thread_id and old_color != new_color:
            print(
                "{} changed the thread color. It will be changed back".format(author_id)
            )
            self.change_thread_color(old_color, thread_id=thread_id)

    def on_emoji_change(self, author_id, new_emoji, thread_id, thread_type, **kwargs):
        if old_thread_id == thread_id and new_emoji != old_emoji:
            print(
                "{} changed the thread emoji. It will be changed back".format(author_id)
            )
            self.change_thread_emoji(old_emoji, thread_id=thread_id)

    def on_people_added(self, added_ids, author_id, thread_id, **kwargs):
        if old_thread_id == thread_id and author_id != session.user_id:
            print("{} got added. They will be removed".format(added_ids))
            for added_id in added_ids:
                self.remove_user_from_group(added_id, thread_id=thread_id)

    def on_person_removed(self, removed_id, author_id, thread_id, **kwargs):
        # No point in trying to add ourself
        if (
            old_thread_id == thread_id
            and removed_id != session.user_id
            and author_id != session.user_id
        ):
            print("{} got removed. They will be re-added".format(removed_id))
            self.add_users_to_group(removed_id, thread_id=thread_id)

    def on_title_change(self, author_id, new_title, thread_id, thread_type, **kwargs):
        if old_thread_id == thread_id and old_title != new_title:
            print(
                "{} changed the thread title. It will be changed back".format(author_id)
            )
            self.change_thread_title(
                old_title, thread_id=thread_id, thread_type=thread_type
            )

    def on_nickname_change(
        self, author_id, changed_for, new_nickname, thread_id, thread_type, **kwargs
    ):
        if (
            old_thread_id == thread_id
            and changed_for in old_nicknames
            and old_nicknames[changed_for] != new_nickname
        ):
            print(
                "{} changed {}'s' nickname. It will be changed back".format(
                    author_id, changed_for
                )
            )
            self.change_nickname(
                old_nicknames[changed_for],
                changed_for,
                thread_id=thread_id,
                thread_type=thread_type,
            )


session = fbchat.Session.login("<email>", "<password>")

keep_bot = KeepBot(session)
keep_bot.listen()