#!/usr/bin/env python

###
# Copyright (c) 2002, Jeremiah Fincher
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###

"""
Enforces capabilities on a channel, watching MODEs, KICKs,
JOINs, etc. to make sure they match the channel's config.  Also handles
auto-opping, auto-halfopping, or auto-voicing, as well as cycling an otherwise
empty channel in order to get ops.
"""

__revision__ = "$Id$"
__author__ = 'Jeremy Fincher (jemfinch) <jemfinch@users.sf.net>'

import supybot.plugins as plugins

import supybot.conf as conf
import supybot.ircdb as ircdb
import supybot.ircmsgs as ircmsgs
import supybot.plugins as plugins
import supybot.ircutils as ircutils
import supybot.privmsgs as privmsgs
import supybot.registry as registry
import supybot.callbacks as callbacks

def configure(advanced):
    from supybot.questions import output, expect, anything, something, yn
    conf.registerPlugin('Enforcer', True)
    chanserv = anything("""What\'s the name of ChanServ on your network?  If
                           there is no ChanServ on your network, just press
                           enter without entering anything.""")
    revenge = yn('Do you want the bot to take revenge on rule breakers?')
    conf.supybot.plugins.Enforcer.ChanServ.set(chanserv)
    conf.supybot.plugins.Enforcer.takeRevenge.setValue(revenge)

class ValidNickOrEmptyString(registry.String):
    def setValue(self, v):
        if v and not ircutils.isNick(v):
            raise registry.InvalidRegistryValue, \
                  'Value must be a valid nick or the empty string.'
        self.value = v

conf.registerPlugin('Enforcer')
conf.registerChannelValue(conf.supybot.plugins.Enforcer, 'enforce',
    registry.Boolean(True, """Determines whether the bot will enforce
    capabilities on this channel.  Basically, if False, it 'turns off' the
    plugin for this channel."""))
conf.registerChannelValue(conf.supybot.plugins.Enforcer, 'autoOp',
    registry.Boolean(False, """Determines whether the bot will automatically op
    people with the <channel>,op capability when they join the channel."""))
conf.registerChannelValue(conf.supybot.plugins.Enforcer, 'autoHalfop',
    registry.Boolean(False, """Determines whether the bot will automatically
    halfop people with the <channel>,halfop capability when they join the
    channel."""))
conf.registerChannelValue(conf.supybot.plugins.Enforcer, 'autoVoice',
    registry.Boolean(False, """Determines whether the bot will automatically
    voice people with the <channel>,voice capability when they join the
    channel."""))
conf.registerChannelValue(conf.supybot.plugins.Enforcer, 'takeRevenge',
    registry.Boolean(False, """Determines whether the bot will take revenge on
    people who do things it doesn't like (somewhat like 'bitch mode' in other
    IRC bots)."""))
conf.registerChannelValue(conf.supybot.plugins.Enforcer, 'takeRevengeOnOps',
    registry.Boolean(False, """Determines whether the bot will even take
    revenge on ops (people with the #channel,op capability) who violate the
    channel configuration."""))
conf.registerChannelValue(conf.supybot.plugins.Enforcer, 'cycleToGetOps',
    registry.Boolean(True, """Determines whether the bot will cycle the channel
    if it doesn't have ops and there's no one else in the channel."""))
# This is a network value, not a channel value.
conf.registerChannelValue(conf.supybot.plugins.Enforcer, 'ChanServ',
    ValidNickOrEmptyString('', """Determines what nick the bot will consider to
    be the ChanServ on the network.  ChanServ (on networks that support it) is
    obviously beyond our abilities to enforce, and so we would ignore all
    messages from it."""))

# Limit stuff
conf.registerGroup(conf.supybot.plugins.Enforcer, 'limit')
conf.registerChannelValue(conf.supybot.plugins.Enforcer.limit, 'enforce',
    registry.Boolean(False, """Determines whether the bot will maintain the
    channel limit to be slightly above the current number of people in the
    channel, in order to make clone/drone attacks harder."""))
conf.registerChannelValue(conf.supybot.plugins.Enforcer.limit, 'minimumExcess',
    registry.PositiveInteger(5, """Determines the minimum number of free
    spots that will be saved when limits are being enforced.  This should
    always be smaller than supybot.plugins.Enforcer.limit.maximumExcess."""))
conf.registerChannelValue(conf.supybot.plugins.Enforcer.limit, 'maximumExcess',
    registry.PositiveInteger(10, """Determines the maximum number of free spots
    that will be saved when limits are being enforced.  This should always be
    larger than supybot.plugins.Enforcer.limit.minimumExcess."""))

_chanCap = ircdb.makeChannelCapability
class Enforcer(callbacks.Privmsg):
    """Manages various things concerning channel security.  Check out the
    supybot.plugins.Enforcer.autoOp, supybot.plugins.Enforcer.autoHalfop,
    supybot.plugins.Enforcer.autoVoice, supybot.plugins.Enforcer.takeRevenge,
    supybot.plugins.Enforcer.cycleToGetOps, and
    supybot.plugins.Enforcer.ChanServ to configure the behavior of this plugin.
    """
    def __init__(self):
        callbacks.Privmsg.__init__(self)
        self.topics = ircutils.IrcDict()

    def _enforceLimit(self, irc, channel):
        if self.registryValue('limit.enforce', channel):
            maximum = self.registryValue('limit.maximumExcess', channel)
            minimum = self.registryValue('limit.minimumExcess', channel)
            assert maximum > minimum
            currentUsers = len(irc.state.channels[channel].users)
            currentLimit = irc.state.channels[channel].modes.get('l', 0)
            if currentLimit - currentUsers < minimum:
                irc.queueMsg(ircmsgs.limit(channel, currentUsers + maximum))
            elif currentLimit - currentUsers > maximum:
                irc.queueMsg(ircmsgs.limit(channel, currentUsers + minimum))
                
    def doJoin(self, irc, msg):
        if msg.nick == irc.nick:
            return
        channel = msg.args[0]
        c = ircdb.channels.getChannel(channel)
        if c.checkBan(msg.prefix):
            irc.queueMsg(ircmsgs.ban(channel, ircutils.banmask(msg.prefix)))
            irc.queueMsg(ircmsgs.kick(channel, msg.nick))
        elif ircdb.checkCapability(msg.prefix, _chanCap(channel, 'op')):
            if self.registryValue('autoOp', channel):
                irc.queueMsg(ircmsgs.op(channel, msg.nick))
        elif ircdb.checkCapability(msg.prefix, _chanCap(channel, 'halfop')):
            if self.registryValue('autoHalfop', channel):
                irc.queueMsg(ircmsgs.halfop(channel, msg.nick))
        elif ircdb.checkCapability(msg.prefix, _chanCap(channel, 'voice')):
            if self.registryValue('autoVoice', channel):
                irc.queueMsg(ircmsgs.voice(channel, msg.nick))
        self._enforceLimit(irc, channel)

    def doTopic(self, irc, msg):
        channel = msg.args[0]
        topic = msg.args[1]
        if msg.nick != irc.nick and channel in self.topics and \
           not ircdb.checkCapabilities(msg.prefix,
                                       (_chanCap(channel, 'op'),
                                        _chanCap(channel, 'topic'))):
            irc.queueMsg(ircmsgs.topic(channel, self.topics[channel]))
            if self.registryValue('takeRevenge', channel):
                irc.queueMsg(ircmsgs.kick(channel, msg.nick,
                                          conf.supybot.replies.noCapability() %
                                          _chanCap(channel, 'topic')))
        else:
            self.topics[channel] = msg.args[1]

    def do332(self, irc, msg):
        # This command gets sent right after joining a channel.
        (channel, topic) = msg.args[1:]
        self.topics[channel] = topic

    def _isProtected(self, channel, hostmask):
        capabilities = [_chanCap(channel, 'op'),_chanCap(channel, 'protected')]
        return ircdb.checkCapabilities(hostmask, capabilities)

    def _isPowerful(self, irc, msg):
        if msg.nick == irc.nick:
            return True # It's me.
        if not ircutils.isUserHostmask(msg.prefix):
            return True # It's a server.
        chanserv = self.registryValue('ChanServ')
        if ircutils.nickEqual(msg.nick, chanserv):
            return True # It's ChanServ.
        capability = _chanCap(msg.args[0], 'op')
        if ircdb.checkCapability(msg.prefix, capability):
            return True # It's a chanop.
        return False    # Default.

    def _revenge(self, irc, channel, hostmask):
        nick = ircutils.nickFromHostmask(hostmask)
        if irc.nick != nick:
            irc.queueMsg(ircmsgs.ban(channel, ircutils.banmask(hostmask)))
            irc.queueMsg(ircmsgs.kick(channel, nick))
        else:
            # This can happen if takeRevengeOnOps is True.
            self.log.info('Tried to take revenge on myself.  '
                          'Are you sure you want takeRevengeOnOps to be True?')

    def doKick(self, irc, msg):
        channel = msg.args[0]
        kicked = msg.args[1].split(',')
        deop = False
        if not self._isPowerful(irc, msg) or \
           self.registryValue('takeRevengeOnOps', channel):
            for nick in kicked:
                hostmask = irc.state.nickToHostmask(nick)
                if nick == irc.nick:
                    # Must be a sendMsg so he joins the channel before MODEing.
                    irc.sendMsg(ircmsgs.join(channel))
                    deop = True
                if self._isProtected(channel, hostmask):
                    deop = True
                    irc.queueMsg(ircmsgs.invite(msg.args[1], channel))
            if deop:
                deop = False
                if self.registryValue('takeRevenge', channel):
                    self._revenge(irc, channel, msg.prefix)
                else:
                    irc.queueMsg(ircmsgs.deop(channel, msg.nick))

    def doMode(self, irc, msg):
        channel = msg.args[0]
        chanserv = self.registryValue('ChanServ', channel)
        if not ircutils.isChannel(channel) or \
           (self._isPowerful(irc, msg) and
            not self.registryValue('takeRevengeOnOps', channel)):
            return
        for (mode, value) in ircutils.separateModes(msg.args[1:]):
            if value == msg.nick:
                continue
            elif mode == '+o' and value != irc.nick:
                hostmask = irc.state.nickToHostmask(value)
                if ircdb.checkCapability(channel,
                                       ircdb.makeAntiCapability('op')):
                    irc.queueMsg(ircmsgs.deop(channel, value))
            elif mode == '+h' and value != irc.nick:
                hostmask = irc.state.nickToHostmask(value)
                if ircdb.checkCapability(channel,
                                       ircdb.makeAntiCapability('halfop')):
                    irc.queueMsg(ircmsgs.dehalfop(channel, value))
            elif mode == '+v' and value != irc.nick:
                hostmask = irc.state.nickToHostmask(value)
                if ircdb.checkCapability(channel,
                                       ircdb.makeAntiCapability('voice')):
                    irc.queueMsg(ircmsgs.devoice(channel, value))
            elif mode == '-o':
                hostmask = irc.state.nickToHostmask(value)
                if self._isProtected(channel, hostmask):
                    irc.queueMsg(ircmsgs.op(channel, value))
                    if self.registryValue('takeRevenge', channel):
                        self._revenge(irc, channel, msg.prefix)
                    else:
                        irc.queueMsg(ircmsgs.deop(channel, msg.nick))
            elif mode == '-h':
                hostmask = irc.state.nickToHostmask(value)
                if self._isProtected(channel, hostmask):
                    irc.queueMsg(ircmsgs.halfop(channel, value))
                    if self.registryValue('takeRevenge', channel):
                        self._revenge(irc, channel, msg.prefix)
                    else:
                        irc.queueMsg(ircmsgs.deop(channel, msg.nick))
            elif mode == '-v':
                hostmask = irc.state.nickToHostmask(value)
                if self._isProtected(channel, hostmask):
                    irc.queueMsg(ircmsgs.voice(channel, value))
                    if self.registryValue('takeRevenge', channel):
                        self._revenge(irc, channel, msg.prefix)
                    else:
                        irc.queueMsg(ircmsgs.deop(channel, msg.nick))
            elif mode == '+b':
                irc.queueMsg(ircmsgs.unban(channel, value))
                if self.registryValue('takeRevenge', channel):
                    self._revenge(irc, channel, msg.prefix)
                else:
                    irc.queueMsg(ircmsgs.deop(channel, msg.nick))

    def _cycle(self, irc, channel):
        if self.registryValue('cycleToGetOps', channel):
            if 'i' not in irc.state.channels[channel].modes:
                # XXX: What about keywords?
                self.log.info('Cycling %s: I\'m the only one left.', channel)
                irc.queueMsg(ircmsgs.part(channel))
                irc.queueMsg(ircmsgs.join(channel))
            else:
                self.log.info('Not cycling %s: it\'s +i', channel)

    def doPart(self, irc, msg):
        if msg.prefix != irc.prefix:
            channel = msg.args[0]
            c = irc.state.channels[channel]
            if len(c.users) == 1:
                if irc.nick not in c.ops:
                    self._cycle(irc, channel)
                    return
            self._enforceLimit(irc, channel)

    def doQuit(self, irc, msg):
        for (channel, c) in irc.state.channels.iteritems():
            if len(c.users) == 1:
                if irc.nick not in c.ops:
                    self._cycle(irc, channel)
                    continue
            self._enforceLimit(irc, channel)

    def __call__(self, irc, msg):
        channel = msg.args[0]
        if ircutils.isChannel(channel) and \
           self.registryValue('enforce', channel):
            chanserv = self.registryValue('ChanServ', irc.network)
            if chanserv:
                if ircutils.isUserHostmask(msg.prefix):
                    if msg.nick != chanserv:
                        callbacks.Privmsg.__call__(self, irc, msg)
            else:
                callbacks.Privmsg.__call__(self, irc, msg)


Class = Enforcer
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