dr.botzo/Module.py

"""
Module - dr.botzo modular functionality base class
Copyright (C) 2010  Brian S. Stephan

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""

from ConfigParser import NoSectionError, NoOptionError
import inspect
import re
import sys

from extlib import irclib

class Module(object):
    """Declare a base class used for creating classes that have real functionality."""

    def __init__(self, config, server, modlist):
        """
        Construct a feature module. Inheritors should not do anything special
        here, instead they should implement register_handlers and do, or else this will
        be a very uneventful affair.

        Classes that are interested in allowing an indirect call to their do routine
        should add themselves to modlist inside their __init__. This will allow other
        modules to call do and see if anything can handle text they may have seen (such
        as in recursive commands).
        """

        self.config = config
        self.server = server
        self.modlist = modlist
        self.register_handlers(server)

        # add self to the object list
        modlist.append(self)

        # print what was loaded, for debugging
        print("loaded " + self.__class__.__name__)

    def register_handlers(self, server):
        """
        Hook handler functions into the IRC library. This is called by __init__ and sets
        up server.add_global_handlers. Classes inheriting from Module could implement this
        and set up the appropriate handlers, e.g.:

        server.add_global_handler('privmsg', self.on_privmsg)

        Module.on_pubmsg and Module.on_privmsg are defined so far, the rest, you're on your
        own.
        """

        server.add_global_handler('pubmsg', self.on_pubmsg)
        server.add_global_handler('privmsg', self.on_privmsg)

    def unregister_handlers(self):
        """
        Unhook handler functions from the IRC library. Inverse of the above.
        This is called by reload, to remove the soon-to-be old object from the server
        global handlers (or whatever has been added via register_handlers). Classes
        inheriting from Module could implement this, e.g.:

        server.remove_global_handler('privmsg', self.on_privmsg)
        """

        self.server.remove_global_handler('pubmsg', self.on_pubmsg)
        self.server.remove_global_handler('privmsg', self.on_privmsg)

    def on_pubmsg(self, connection, event):
        """
        Handle pubmsg events. Does some variable setup and initial sanity checking before
        calling Module.do, which should be implemented by subclasses and what can be
        ultimately responsible for the work.

        Of course, you are free to reimplement on_pubmsg on your own too.
        """

        nick = irclib.nm_to_n(event.source())
        userhost = irclib.nm_to_uh(event.source())
        replypath = event.target()
        what = event.arguments()[0]

        admin_unlocked = False

        try:
            if userhost == self.config.get('dr.botzo', 'admin_userhost'):
                admin_unlocked = True
        except NoOptionError: pass

        # only do commands if the bot has been addressed directly
        addressed_pattern = '^' + connection.get_nickname() + '[:,]?\s+'
        addressed_re = re.compile(addressed_pattern)

        need_prefix = True
        try:
            need_prefix = self.config.getboolean(self.__class__.__name__, 'meta.pubmsg_needs_bot_prefix')
        except NoOptionError: pass
        except NoSectionError: pass

        ignore_prefix = False
        try:
            ignore_prefix = self.config.getboolean(self.__class__.__name__, 'meta.pubmsg_ignore_bot_prefix')
        except NoOptionError: pass
        except NoSectionError: pass

        strip_bot_name_from_input = True
        try:
            strip_bot_name_from_input = self.config.getboolean(self.__class__.__name__, 'meta.strip_bot_name_from_input')
        except NoOptionError: pass
        except NoSectionError: pass

        if not addressed_re.match(what) and need_prefix:
            return
        elif addressed_re.match(what) and ignore_prefix:
            return
        elif strip_bot_name_from_input:
            what = addressed_re.sub('', what)

        skip_recursion_scan = False
        try:
            skip_recursion_scan = self.config.getboolean(self.__class__.__name__, 'meta.skip_recursion_scan')
        except NoOptionError: pass
        except NoSectionError: pass

        if replypath is not None and skip_recursion_scan is False:
            what = self.try_recursion(connection, event, nick, userhost, replypath, what, admin_unlocked)

        # try reloading
        self.reload(connection, event, nick, userhost, replypath, what, admin_unlocked)

        self.do(connection, event, nick, userhost, replypath, what, admin_unlocked)

    def on_privmsg(self, connection, event):
        """
        Handle privmsg events. Does some variable setup and initial sanity checking before
        calling Module.do, which should be implemented by subclasses and what can be
        ultimately responsible for the work.

        Of course, you are free to reimplement on_privmsg on your own too.
        """

        nick = irclib.nm_to_n(event.source())
        userhost = irclib.nm_to_uh(event.source())
        replypath = nick
        what = event.arguments()[0]

        admin_unlocked = False

        try:
            if userhost == self.config.get('dr.botzo', 'admin_userhost'):
                admin_unlocked = True
        except NoOptionError: pass

        if replypath is not None:
            what = self.try_recursion(connection, event, nick, userhost, replypath, what, admin_unlocked)

        self.do(connection, event, nick, userhost, replypath, what, admin_unlocked)

    def reload(self, connection, event, nick, userhost, replypath, what, admin_unlocked):
        """Reload this module's code and then create a new object of it, removing the old."""

        whats = what.split(' ')
        if whats[0] == 'reload' and admin_unlocked:
            # re-read and re-compile module from source on disk
            reload(sys.modules[self.__module__])

            # find the class declaration for the current module
            for name, obj in inspect.getmembers(sys.modules[self.__module__]):
                if inspect.isclass(obj) and str(obj).find(self.__module__) > 0:
                    # remove existing object from in-memory stuff
                    self.modlist.remove(self)
                    self.unregister_handlers()

                    # create new object, like how we did initially
                    obj(self.config, self.server, self.modlist)

    def reply(self, connection, replypath, replystr):
        """
        Reply over IRC to replypath or return a string with the reply.
        Utility method to do the proper type of reply (either to IRC, or as a return
        to caller) depending on the target. Pretty simple, and included in the base
        class for convenience. It should be the last step for callers:

        return self.reply(connection, replypath, 'hello')
        """

        if replypath is None:
            return replystr
        else:
            connection.privmsg(replypath, replystr)

    def try_recursion(self, connection, event, nick, userhost, replypath, what, admin_unlocked):
        """
        Scan message for subcommands to execute and use as part of this command.
        Upon seeing a line intended for this module, see if there are subcommands
        that we should do what is basically a text replacement on. The intent is to
        allow things like the following:

        command arg1 [anothercommand arg1 arg2]

        where the output of anothercommand is command's arg2..n. It's mostly for
        amusement purposes, but maybe there are legitimate uses. This is intended to
        be attempted after you've determined the line should be handled by your module.
        """

        start_idx = what.find('[')
        subcmd = what[start_idx+1:]
        end_idx = subcmd.rfind(']')
        subcmd = subcmd[:end_idx]

        attempt = what

        if start_idx == -1 or end_idx == -1:
            # no nested commands at all if replypath is a real value, so don't do a damn thing
            if replypath is not None:
                return attempt
            # no more replacements found, see if what we had is workable
            else:
                for module in self.modlist:
                    ret = module.do(connection, event, nick, userhost, None, attempt, admin_unlocked)
                    if ret is not None:
                        return ret

                # if we got here, it's not workable. just return what we got
                return attempt
        else:
            # we have a subcmd, see if there's another one nested
            ret = self.try_recursion(connection, event, nick, userhost, None, subcmd, admin_unlocked)
            if ret is not None:
                blarg = attempt.replace('['+subcmd+']', ret)
                if replypath is not None:
                    return blarg
                else:
                    return self.try_recursion(connection, event, nick, userhost, None, blarg, admin_unlocked)
            else:
                return attempt

    def remove_metaoptions(self, list):
        """Remove metaoptions from provided list, which was probably from a config file."""

        list.remove('debug')
        # if this option has been provided, don't print it
        try:
            self.config.get(self.__class__.__name__, 'meta.pubmsg_needs_bot_prefix')
            list.remove('meta.pubmsg_needs_bot_prefix')
        except NoOptionError: pass

    def retransmit_event(self, event):
        """
        Pretend that some event the bot has generated is rather an incoming IRC
        event. Why one would do this is unclear, but I wrote it and then realized
        I didn't need it.
        """

        self.server._handle_event(event)

    def do(self, connection, event, nick, userhost, replypath, what, admin_unlocked):
        """
        Do the primary thing this module was intended to do.
        Implement this method in your subclass to have a fairly-automatic hook into
        IRC functionality. This is called by the default on_pubmsg and on_privmsg
        """

        print "looks like someone forgot to implement do!"

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