###
# Copyright (c) 2004, Jeremiah Fincher
# All rights reserved.
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# 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,
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#     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
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###

"""
A module to observe things in the channel and call commands based on what is
seen.
"""

__revision__ = "$Id$"
__author__ = ''

import supybot.plugins as plugins

import random

import supybot.conf as conf
import supybot.utils as utils
from supybot.commands import *
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('Observer', True)

class Observers(registry.SpaceSeparatedListOfStrings):
    List = callbacks.CanonicalNameSet

class ActiveObservers(registry.SpaceSeparatedListOfStrings):
    String = callbacks.canonicalName

conf.registerPlugin('Observer')
conf.registerGlobalValue(conf.supybot.plugins.Observer, 'observers',
    Observers([], """Determines what observers are available.""",
    orderAlphabetically=True))
conf.registerChannelValue(conf.supybot.plugins.Observer.observers, 'active',
    ActiveObservers([], """Determines what observers are
    active on a channel."""))


def registerObserver(name, regexpString='',
                     commandString='', probability=None):
    g = conf.registerGlobalValue(conf.supybot.plugins.Observer.observers,
            name, registry.Regexp(regexpString, """Determines what regexp must
            match for this observer to be executed."""))
    if regexpString:
        g.set(regexpString) # This is in case it's been registered.
    conf.registerGlobalValue(g, 'command', registry.String('', """Determines
        what command will be run when this observer is executed."""))
    if commandString:
        g.command.setValue(commandString)
    conf.registerGlobalValue(g, 'probability',
        registry.Probability(1.0, """ Determines what the probability
        of executing this observer is if it matches."""))
    if probability is not None:
        g.probability.setValue(probability)
    conf.supybot.plugins.Observer.observers().add(name)
    return g

def unregisterObserver(name):
    g = conf.supybot.plugins.Observer.observers
    g.unregister(name)
    g().remove(name)
    if name in g.active():
        g.active().remove(name)

def getObserver(irc, msg, args, state):
    if args[0] != 'active' and registry.isValidRegistryName(args[0]):
        state.args.append(args.pop(0))
    else:
        irc.errorInvalid('Observer name',
                         s='Please be sure there are no spaces in the name.')

addConverter('observer', getObserver)

class Observer(callbacks.Privmsg):
    commandCalled = False
    def __init__(self):
        self.__parent = super(Observer, self)
        self.__parent.__init__()
        for name in self.registryValue('observers'):
            registerObserver(name)

    def callCommand(self, *args, **kwargs):
        self.commandCalled = True
        self.__parent.callCommand(*args, **kwargs)

    def doPrivmsg(self, irc, msg):
        if self.commandCalled:
            self.commandCalled = False
            return
        channel = msg.args[0]
        observers = self.registryValue('observers')
        active = self.registryValue('observers.active', channel)
        for name in active:
            if name not in observers:
                self.log.error('Active observers for %s include an '
                               'invalid observer: %s.', channel, name)
                continue
            observer = self.registryValue('observers.%s' % name, value=False)
            probability = observer.probability()
            if random.random() > probability:
                continue
            r = observer() # The regexp.
            m = r.search(msg.args[1])
            if m is not None:
                command = observer.command()
                groups = filter(None, list(m.groups()))
                groups.insert(0, m.group(0))
                for (i, group) in enumerate(groups):
                    command = command.replace('$%s' % i, group)
                tokens = callbacks.tokenize(command, channel=channel)
                self.Proxy(irc, msg, tokens)

    def list(self, irc, msg, args, channel):
        """[<channel>]

        Lists the currently available observers.  If <channel> is given,
        returns the currently active observers on <channel>.
        """
        if channel:
            # We don't use getChannel here because we don't want it to
            # automatically pick the channel if the message is sent in
            # the channel itself.
            if not irc.isChannel(channel):
                raise callbacks.ArgumentError
            observers = self.registryValue('observers.active', channel)
            # We don't sort because order matters.
        else:
            observers = self.registryValue('observers')
            observers = sorted(observers, key=str.lower)
        if observers:
            irc.reply(utils.commaAndify(observers))
        else:
            irc.reply('There were no relevant observers.')
    list = wrap(list, [additional('something')])

    def enable(self, irc, msg, args, channel, name):
        """[<channel>] <name>

        Enables the observer <name> in <channel>.  <channel> is only
        necessary if the message isn't sent in the channel itself.
        """
        if name not in self.registryValue('observers'):
            irc.error('There is no observer %s.' % name, Raise=True)
        self.registryValue('observers.active', channel).append(name)
        irc.replySuccess()
    enable = wrap(enable, [('checkChannelCapability', 'op'), 'observer'])

    def disable(self, irc, msg, args, channel, name):
        """[<channel>] <name>

        Disables the observer <name> in <channel>.  <channel> is only
        necessary if the message isn't sent in the channel itself.
        """
        try:
            self.registryValue('observers.active', channel).remove(name)
            irc.replySuccess()
        except (KeyError, ValueError):
            irc.error('The observer %s was not active on %s.' % (name,channel))
    disable = wrap(disable, [('checkChannelCapability', 'op'), 'observer'])

    def info(self, irc, msg, args, channel, name):
        """[<channel>] <name>

        Returns the relevant information on the observer specified by <name>.
        <channel> is only necessary if the message isn't sent in the channel
        itself.
        """
        if name not in self.registryValue('observers'):
            irc.error('That\'s not a valid observer.', Raise=True)
        g = self.registryValue('observers.%s' % name, value=False)
        command = g.command()
        probability = g.probability()
        if name in self.registryValue('observers.active', channel):
            active = 'active'
        else:
            active = 'inactive'
        irc.reply('%s matches the regular expression %s and '
                  'runs the command <<%s>> with a probability of %s.  '
                  'Currently %s.' %
                  (name, g, command, probability, active))
    info = wrap(info, ['channel', 'observer'])

    def add(self, irc, msg, args, name, probability, regexp, command):
        """<name> [<probability>] <regexp> <command>

        Calls <command> when <regexp> matches a given message.  Before
        being called, <command> has the standard substitute applied to it,
        as well as having $1, $2, etc. replaced by the appropriate groups
        of the regexp.  If <probability> is not given, it defaults to 1;
        otherwise it should be a floating point probability that the observer
        will execute if it matches.
        """
        registerObserver(name, regexp, command, probability)
        irc.replySuccess()
    add = wrap(add, ['observer',
                     optional('float', 1.0),
                     ('regexpMatcher', False),
                     'text'])

    def remove(self, irc, msg, args, name):
        """<name>

        Removes the observer <name>.
        """
        try:
            unregisterObserver(name)
            irc.replySuccess()
        except KeyError:
            irc.error('That observer does not exist.')
    remove = wrap(remove, ['observer'])


Class = Observer

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