xbotlib/xbotlib.py

"""XMPP bots for humans."""

from argparse import ArgumentParser, BooleanOptionalAction
from configparser import ConfigParser
from getpass import getpass
from os import environ
from os.path import exists
from pathlib import Path

from slixmpp import ClientXMPP


class SimpleMessage:
    """A simple message interface."""

    def __init__(self, message):
        self.message = message

    @property
    def body(self):
        return self.message["body"]

    @property
    def source(self):
        return self.message["from"]

    @property
    def room(self):
        return self.message["from"].bare

    @property
    def receiver(self):
        return self.message["to"]

    @property
    def nickname(self):
        return self.message["mucnick"]

    @property
    def type(self):
        return self.message["type"]


class Bot(ClientXMPP):
    CONFIG_FILE = "bot.conf"

    def __init__(self):
        self.parse_arguments()
        self.read_config()
        self.init_bot()
        self.register_xmpp_event_handlers()
        self.register_xmpp_plugins()
        self.run()

    def parse_arguments(self):
        """Parse command-line arguments."""
        self.parser = ArgumentParser()
        self.parser.add_argument(
            "--input",
            help="Read configuration from environment",
            action=BooleanOptionalAction,
            default=True,
        )
        self.args = self.parser.parse_args()

    def read_config(self):
        """Read configuration for running bot."""
        self.config = ConfigParser()

        config_file_path = Path(self.CONFIG_FILE).absolute()
        if not exists(config_file_path) and self.args.input:
            self.generate_config_interactively()

        if exists(config_file_path):
            self.config.read(config_file_path)

        if self.args.input is False:
            self.read_config_from_env()

        if "bot" not in self.config:
            raise RuntimeError("Failed to configure bot")

    def generate_config_interactively(self):
        """Generate bot configuration."""
        jid = input("XMPP address (e.g. foo@bar.com): ") or "foo@bar.com"
        password = (
            getpass("Password (e.g. my-cool-password): ") or "my-cool-password"
        )
        room = input("XMPP room (e.g. foo@muc.bar.com): ")
        nick = input("Nickname (e.g. lurkbot): ")

        config = ConfigParser()
        config["bot"] = {"jid": jid, "password": password}

        if room:
            config["bot"]["room"] = room
        if nick:
            config["bot"]["nick"] = nick

        with open("bot.conf", "w") as file_handle:
            config.write(file_handle)

    def read_config_from_env(self):
        """Read configuration from the environment."""
        self.config["bot"] = {}
        self.config["bot"]["jid"] = environ.get("XBOT_JID")
        self.config["bot"]["password"] = environ.get("XBOT_PASSWORD")
        self.config["bot"]["room"] = environ.get("XBOT_ROOM", "")
        self.config["bot"]["nick"] = environ.get("XBOT_NICK", "")

    def init_bot(self):
        """Initialise bot with connection details."""
        jid = self.config["bot"]["jid"]
        password = self.config["bot"]["password"]
        ClientXMPP.__init__(self, jid, password)

    def register_xmpp_event_handlers(self):
        """Register functions against specific XMPP event handlers."""
        self.add_event_handler("session_start", self.session_start)
        self.add_event_handler("message", self.message)
        self.add_event_handler("groupchat_message", self.groupchat_message)

    def message(self, message):
        """Handle message event."""
        if message["type"] in ("chat", "normal"):
            self.react(SimpleMessage(message))

    def session_start(self, event):
        """Handle session_start event."""
        self.send_presence()
        self.get_roster()

        room = self.config["bot"].get("room")
        nick = self.config["bot"].get("nick")

        if room and nick:
            self.plugin["xep_0045"].join_muc(room, nick)

    def groupchat_message(self, message):
        """Handle groupchat_message event."""
        if message["type"] in ("groupchat", "normal"):
            if message["mucnick"] != self.config["bot"]["nick"]:
                self.react(SimpleMessage(message))

    def register_xmpp_plugins(self):
        """Register XMPP plugins that the bot supports."""
        self.register_plugin("xep_0030")  # Service Discovery
        self.register_plugin("xep_0045")  # Multi-User Chat
        self.register_plugin("xep_0199")  # XMPP Ping

    def run(self):
        """Run the bot."""
        self.connect()

        try:
            self.process()
        except KeyboardInterrupt:
            pass

    def reply(self, body, to=None, room=None):
        """Send back a reply."""
        if to is None and room is None:
            message = "`to` or `room` arguments required for `reply`"
            raise RuntimeError(message)

        if to is not None and room is not None:
            message = "Cannot send to both `to` and `room` for `reply`"
            raise RuntimeError(message)

        kwargs = {"mbody": body}
        if to is not None:
            kwargs["mto"] = to
            kwargs["mtype"] = "chat"
        else:
            kwargs["mto"] = room
            kwargs["mtype"] = "groupchat"

        self.send_message(**kwargs)

    def react(self, message):
        message = "You need to write your own `react` implementation"
        raise NotImplementedError(message)


class EchoBot(Bot):
    """Gives back what you sent it.

    Just direct message the bot and see if you get back what you sent. It also
    works in group chats but in this case you need to summon the bot using its
    nickname Usually like so.

    echobot:foo

    """

    def react(self, message):
        """Send back what we get."""
        if message.type == "chat":
            self.reply(message.body, to=message.source)

        if message.type == "groupchat" and "echobot" in message.body:
            _, to_echo = message.body.split(":")
            self.reply(to_echo, room=message.room)


class WhisperBot(Bot):
    """Pseudo-anonymous whispering in group chats.

    In order to activate this bot you can invite it to your group chat. Once
    invited, you can directly message the bot outside of the group chat and
    tell it you want it to whisper your message into the group chat. The bot
    will then do this on your behalf and not reveal your identity. This is nice
    when you want to communicate with the group somewhat anonymously.

    The bot accepts messages in the following form.

    whisper:<room>:<message>

    So, I might write it like so.

    whisper:myroom@muc.foo.com:i love the music of avril lavigne

    """

    def react(self, message):
        """Receive direct messages and pass them to group chats."""
        if message.type == "chat" and "whisper" in message.body:
            _, room, whisper = message.body.split(":")
            self.reply(f"*whispers* {whisper}", room=room)