"""Observe Markov chains from Discord."""
import logging

from django.conf import settings

from bot import hitomi
from markov import lib

logger = logging.getLogger(__name__)
logger.info("loading markov plugin")


def on_message(message):
    """Keep the observed Markov chains."""
    # ignore self
    if message.author == hitomi.user:
        logger.debug("markov ignoring message authored by self")
        return

    # ignore commands
    if message.content[0] == settings.DISCORD_BOT_COMMAND_PREFIX:
        logger.debug("markov ignoring message that looks like a command")
        return

    if message.channel.is_private:
        # DMs have a context of the author
        context_name = message.author
    else:
        # channels have a context of the server, but we should ignore channels that override @everyone's read ability
        for changed_role in message.channel.changed_roles:
            if changed_role.is_everyone:
                if not changed_role.permissions.read_messages:
                    logger.debug("markov ignoring channel that @everyone can't read")
                    return
        context_name = message.server.id

    lib.learn_line(message.content, context_name)


hitomi.on_message_handlers.append(on_message)