###
# Copyright (c) 2004, Jeremiah Fincher
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
#   * Redistributions of source code must retain the above copyright notice,
#     this list of conditions, and the following disclaimer.
#   * Redistributions in binary form must reproduce the above copyright notice,
#     this list of conditions, and the following disclaimer in the
#     documentation and/or other materials provided with the distribution.
#   * Neither the name of the author of this software nor the name of
#     contributors to this software may be used to endorse or promote products
#     derived from this software without specific prior written consent.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
###

"""
This plugin handles channel limits (MODE +l).
"""

import supybot

__revision__ = "$Id$"
__author__ = supybot.authors.jemfinch
__contributors__ = {}


import supybot.conf as conf
import supybot.utils as utils
import supybot.plugins as plugins
import supybot.privmsgs as privmsgs
import supybot.registry as registry
import supybot.callbacks as callbacks


def configure(advanced):
    # This will be called by setup.py to configure this module.  Advanced is
    # a bool that specifies whether the user identified himself as an advanced
    # user or not.  You should effect your configuration by manipulating the
    # registry as appropriate.
    from supybot.questions import expect, anything, something, yn
    conf.registerPlugin('Limiter', True)

conf.registerPlugin('Limiter')
conf.registerChannelValue(conf.supybot.plugins.Limiter, 'enable',
    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.Limiter, '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.Limiter.limit.maximumExcess."""))
conf.registerChannelValue(conf.supybot.plugins.Limiter, '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.Limiter.limit.minimumExcess."""))

class Limiter(callbacks.Privmsg):
    def _enforceLimit(self, irc, channel):
        if self.registryValue('enable', channel):
            maximum = self.registryValue('maximumExcess', channel)
            minimum = self.registryValue('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:
                self._enforce(irc, ircmsgs.limit(channel,currentUsers+maximum))
            elif currentLimit - currentUsers > maximum:
                self._enforce(irc, ircmsgs.limit(channel,currentUsers+minimum))

    def doJoin(self, irc, msg):
        if not ircutils.strEqual(msg.nick, irc.nick):
            self._enforceLimit(irc, msg.args[0])
    doPart = doJoin
    doKick = doJoin

    def doQuit(self, irc, msg):
        for channel in irc.state.channels:
            self._enforceLimit(irc, channel)


Class = Limiter

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