Limnoria/src/callbacks.py

#!/usr/bin/env python

###
# Copyright (c) 2002, 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 module contains the basic callbacks for handling PRIVMSGs.  Both Privmsg
and PrivmsgRegexp classes are provided; for offering callbacks based on
commands and their arguments (much like *nix command line programs) use the
Privmsg class; for offering callbacks based on regular expressions, use the
PrivmsgRegexp class.  Read their respective docstrings for more information on
how to use them.
"""

from fix import *

import re
import new
import sets
import time
import shlex
import getopt
import inspect
import textwrap
import threading
from cStringIO import StringIO

import conf
import utils
import world
import ircdb
import irclib
import ircmsgs
import ircutils

import debug

###
# Privmsg: handles privmsg commands in a standard fashion.
###
def addressed(nick, msg):
    """If msg is addressed to 'name', returns the portion after the address.
    Otherwise returns the empty string.
    """
    if msg.args[0] == nick:
        if msg.args[1][0] in conf.prefixChars:
            return msg.args[1][1:].strip()
        else:
            return msg.args[1].strip()
    elif ircutils.toLower(msg.args[1]).startswith(nick):
        try:
            return msg.args[1].split(None, 1)[1].strip()
        except IndexError:
            return ''
    elif msg.args[1] and msg.args[1][0] in conf.prefixChars:
        return msg.args[1][1:].strip()
    else:
        return ''

def canonicalName(command):
    """Turn a command into its canonical form.

    Currently, this makes everything lowercase and removes all dashes and
    underscores.
    """
    return command.translate(string.ascii, '\t -_').lower()

def reply(msg, s, prefixName=True):
    """Makes a reply to msg with the payload s"""
    s = ircutils.safeArgument(s)
    if ircutils.isChannel(msg.args[0]):
        if prefixName:
            m = ircmsgs.privmsg(msg.args[0], '%s: %s' % (msg.nick, s))
        else:
            m = ircmsgs.privmsg(msg.args[0], s)
    else:
        m = ircmsgs.privmsg(msg.nick, s)
    return m

def error(msg, s):
    """Makes an error reply to msg with the appropriate error payload."""
    return reply(msg, 'Error: ' + s)

class RateLimiter:
    """This class is used to rate limit replies to certain people, in order to
    prevent abuse of the bot.  Basically, you put messages in with the .put
    method, and then take a message out with the .get method.  .get may return
    None if there is no message waiting that isn't being rate limited.
    """
    # lastRequest must be class-global, so each instance of it uses the same
    # information.  Otherwise, if it was an instance variable, then rate
    # limiting would only work within a single plugin.
    lastRequest = {}
    def __init__(self):
        self.limited = []
        self.unlimited = []

    def get(self):
        if self.unlimited:
            return self.unlimited.pop(0)
        elif self.limited:
            for i in range(len(self.limited)):
                msg = self.limited[i]
                if not self.limit(msg, penalize=False):
                    return self.limited.pop(i)
            return None
        else:
            return None

    def put(self, msg):
        t = self.limit(msg)
        if t and not world.testing:
            s = 'Limiting message from %s for %s seconds' % (msg.prefix, t)
            debug.msg(s, 'normal')
            self.limited.append(msg)
        else:
            self.unlimited.append(msg)

    def limit(self, msg, penalize=True):
        if msg.prefix and ircutils.isUserHostmask(msg.prefix):
            (nick, user, host) = ircutils.splitHostmask(msg.prefix)
            key = '@'.join((user, host))
            now = time.time()
            if ircdb.checkCapabilities(msg.prefix, ('owner', 'admin')):
                return 0
            if key in self.lastRequest:
                # Here's how we throttle requests.  We keep a dictionary of
                # (lastRequest, wait period) tuples.  When a request arrives,
                # we check to see if we have a lastRequest tuple, and if so,
                # we check to make sure that lastRequest was more than wait
                # seconds ago.  If not, we're getting flooded, and we set
                # the lastRequest time to the current time and increment wait,
                # thus making it even harder for the flooder to get us to
                # send them messages.
                (t, wait) = self.lastRequest[key]
                if now - t <= wait:
                    if penalize:
                        newWait = wait + conf.throttleTime
                    else:
                        newWait = wait - (now - t)
                    self.lastRequest[key] = (now, newWait)
                    return newWait
                else:
                    self.lastRequest[key] = (now, conf.throttleTime)
                    return 0
            else:
                self.lastRequest[key] = (now, conf.throttleTime)
                return 0
        else:
            return 0


class Error(Exception):
    """Generic class for errors in Privmsg callbacks."""
    pass

class ArgumentError(Error):
    """The bot replies with a help message when this is raised."""
    pass

class CannotNest(Error):
    """Exception to be raised by commands that cannot be nested."""
    pass

class Tokenizer:
    # This will be used as a global environment to evaluate strings in.
    # Evaluation is, of course, necessary in order to allowed escaped
    # characters to be properly handled.
    #
    # These are the characters valid in a token.  Everything printable except
    # double-quote, left-bracket, and right-bracket.
    validChars = string.ascii[33:].translate(string.ascii, '"[]|')
    def __init__(self, tokens=''):
        self.validChars = self.validChars.translate(string.ascii, tokens)

    def handleToken(self, token):
        while token and token[0] == '"' and token[-1] == token[0]:
            if len(token) > 1:
                token = token[1:-1].decode('string_escape') # 2.3+
            else:
                break
        return token

    def insideBrackets(self, lexer):
        ret = []
        while True:
            token = lexer.get_token()
            if not token:
                raise SyntaxError, 'Missing "]"'
            elif token == ']':
                return ret
            elif token == '[':
                ret.append(self.insideBrackets(lexer))
            else:
                ret.append(self.handleToken(token))
        return ret

    def tokenize(self, s):
        lexer = shlex.shlex(StringIO(s))
        lexer.commenters = ''
        lexer.quotes = '"'
        lexer.wordchars = self.validChars
        args = []
        ends = []
        while True:
            token = lexer.get_token()
            #debug.printf(repr(token))
            if not token:
                break
            elif token == '|':
                if not args:
                    raise SyntaxError, '"|" with nothing preceding'
                ends.append(args)
                args = []
            elif token == '[':
                args.append(self.insideBrackets(lexer))
            elif token == ']':
                raise SyntaxError, 'Spurious "["'
            else:
                args.append(self.handleToken(token))
        if ends:
            if not args:
                raise SyntaxError, '"|" with nothing following'
            args.append(ends.pop())
            while ends:
                args[-1].append(ends.pop())
        return args

def tokenize(s):
    """A utility function to create a Tokenizer and tokenize a string."""
    start = time.time()
    try:
        args = Tokenizer().tokenize(s)
    except ValueError, e:
        raise SyntaxError, str(e)
    debug.msg('tokenize took %s seconds.' % (time.time() - start), 'verbose')
    return args

def findCallbackForCommand(irc, commandName):
    """Given a command name and an Irc object, returns the callback that
    command is in.  Returns None if there is no callback with that command."""
    for callback in irc.callbacks:
        if not isinstance(callback, PrivmsgRegexp):
            if hasattr(callback, 'isCommand'):
                if callback.isCommand(commandName):
                    return callback
    return None

class IrcObjectProxy:
    "A proxy object to allow proper nested of commands (even threaded ones)."
    def __init__(self, irc, msg, args):
        #debug.printf('__init__: %s' % args)
        if not args:
            irc.reply(msg, '[]')
        else:
            self.irc = irc
            self.msg = msg
            self.args = args
            self.counter = 0
            self.finalEvaled = False
            self.prefixName = True
            self.noLengthCheck = False
            world.commandsProcessed += 1
            self.evalArgs()

    def findCallback(self, commandName):
        # Mostly for backwards compatibility now.
        return findCallbackForCommand(self.irc, commandName)

    def evalArgs(self):
        while self.counter < len(self.args):
            if type(self.args[self.counter]) == str:
                self.counter += 1
            else:
                IrcObjectProxy(self, self.msg, self.args[self.counter])
                return
        self.finalEval()

    def finalEval(self):
        if self.finalEvaled:
            raise ValueError, 'finalEval called twice.  Odd.'
        self.finalEvaled = True
        originalName = self.args.pop(0)
        name = canonicalName(originalName)
        callback = self.findCallback(name)
        try:
            if callback is not None:
                anticap = ircdb.makeAntiCapability(name)
                #debug.printf('Checking for %s' % anticap)
                if ircdb.checkCapability(self.msg.prefix, anticap):
                    #debug.printf('Being prevented with anticap')
                    debug.msg('Preventing %s from calling %s' % \
                              (self.msg.nick, name), 'normal')
                    return
                recipient = self.msg.args[0]
                if ircutils.isChannel(recipient):
                    chancap = ircdb.makeChannelCapability(recipient, anticap)
                    #debug.printf('Checking for %s' % chancap)
                    if ircdb.checkCapability(self.msg.prefix, chancap):
                        #debug.printf('Being prevented with chancap')
                        debug.msg('Preventing %s from calling %s' % \
                                  (self.msg.nick, name), 'normal')
                        return
                command = getattr(callback, name)
                callback.callCommand(command, self, self.msg, self.args)
            else:
                self.args.insert(0, originalName)
                if not isinstance(self.irc, irclib.Irc):
                    # If self.irc is an actual irclib.Irc, then this is the
                    # first command given, and should be ignored as usual.
                    self.reply(self.msg, '[%s]' % ' '.join(self.args))
        except (getopt.GetoptError, ArgumentError):
            if hasattr(command, '__doc__'):
                s = '%s %s' % (name, command.__doc__.splitlines()[0])
            else:
                s = 'Invalid arguments for %s.' % name
            self.reply(self.msg, s)
        except CannotNest, e:
            if not isinstance(self.irc, irclib.Irc):
                self.error(self.msg, 'Command %r cannot be nested.' % name)
        except (SyntaxError, Error), e:
            self.reply(self.msg, debug.exnToString(e))
        except Exception, e:
            debug.recoverableException()
            self.error(self.msg, debug.exnToString(e))

    def reply(self, msg, s, noLengthCheck=False, prefixName=True):
        self.noLengthCheck |= noLengthCheck
        self.prefixName &= prefixName
        if self.finalEvaled:
            if isinstance(self.irc, self.__class__):
                self.irc.reply(msg, s, self.noLengthCheck, self.prefixName)
            elif self.noLengthCheck:
                self.irc.queueMsg(reply(msg, s, self.prefixName))
            else:
                # The size of a PRIVMSG is:
                # 1 for the colon
                # len(prefix)
                # 1 for the space
                # 7 for the PRIVMSG
                # 1 for the space
                # len(target)
                # 1 for the space
                # 1 for the colon
                # len(payload)
                # 2 for the \r\n
                # So non-variable stuff it's 1+1+7+1+1+1+2, or 14
                # We'll estimate the channel length at 30, and we'll know the
                # prefix length exactly.  We also might append the string
                # " (more)" to the end, so that's 7 more characters.
                # 512 - 51 == 461.
                s = ircutils.safeArgument(s)
                allowedLength = 463 - len(self.irc.prefix)
                msgs = textwrap.wrap(s, allowedLength-30) # -30 is for "nick:"
                msgs.reverse()
                response = msgs.pop()
                if msgs:
                    response += ' \x02(%s)\x0F' % \
                                utils.nItems(len(msgs), 'message', 'more')
                mask = msg.prefix.split('!', 1)[1]
                Privmsg._mores[mask] = msgs
                self.irc.queueMsg(reply(msg, response, self.prefixName))
        else:
            self.args[self.counter] = s
            self.evalArgs()

    def error(self, msg, s):
        if isinstance(self.irc, self.__class__):
            self.irc.error(msg, s)
        else:
            self.irc.queueMsg(reply(msg, 'Error: ' + s))

    def killProxy(self):
        if not isinstance(self.irc, irclib.Irc):
            self.irc.killProxy()
        self.__dict__ = {}

    def getRealIrc(self):
        if isinstance(self.irc, irclib.Irc):
            return self.irc
        else:
            return self.irc.getRealIrc()

    def __getattr__(self, attr):
        #return getattr(self.getRealIrc(), attr)
        return getattr(self.irc, attr)


class CommandThread(threading.Thread):
    """Just does some extra logging and error-recovery for commands that need
    to run in threads.
    """
    def __init__(self, command, irc, msg, args):
        self.command = command
        world.threadsSpawned += 1
        try:
            self.commandName = command.im_func.func_name
        except AttributeError:
            self.commandName = command.__name__
        try:
            self.className = command.im_class.__name__
        except AttributeError:
            self.className = '<unknown>'
        name = '%s.%s with args %r' % (self.className, self.commandName, args)
        threading.Thread.__init__(self, target=command, name=name,
                                  args=(irc, msg, args))
        debug.msg('Spawning thread %s' % name, 'verbose')
        self.irc = irc
        self.msg = msg
        self.setDaemon(True)

    def run(self):
        try:
            start = time.time()
            threading.Thread.run(self)
            elapsed = time.time() - start
            debug.msg('%s.%s took %s seconds.' % \
                      (self.className, self.commandName, elapsed), 'verbose')
        except (getopt.GetoptError, ArgumentError):
            if hasattr(self.command, '__doc__'):
                help = self.command.__doc__.splitlines()[0]
                s = '%s %s' % (self.commandName, help)
            else:
                s = 'Invalid arguments for %s.' % self.commandName
            self.irc.reply(self.msg, s)
        except CannotNest:
            if not isinstance(self.irc.irc, irclib.Irc):
                s = 'Command %r cannot be nested.' % self.commandName
                self.irc.error(self.msg, s)
        except (SyntaxError, Error), e:
            self.irc.reply(self.msg, debug.exnToString(e))
        except Exception, e:
            debug.recoverableException()
            self.irc.error(self.msg, debug.exnToString(e))


class ConfigIrcProxy(object):
    """Used as a proxy Irc object during configuration. """
    def __init__(self, irc):
        self.__dict__['irc'] = irc
        
    def reply(self, msg, s):
        return None

    def error(self, msg, s):
        debug.msg('ConfigIrcProxy saw an error: %s' % s, 'normal')

    findCallback = IrcObjectProxy.findCallback.im_func

    def getRealIrc(self):
        irc = self.__dict__['irc']
        while(hasattr(irc, 'getRealIrc')):
            irc = irc.getRealIrc()
        return irc

    def __getattr__(self, attr):
        return getattr(self.getRealIrc(), attr)

    def __setattr__(self, attr, value):
        setattr(self.getRealIrc(), attr, value)

    
class Privmsg(irclib.IrcCallback):
    """Base class for all Privmsg handlers."""
    threaded = False
    public = True
    commandArgs = ['self', 'irc', 'msg', 'args']
    _mores = {} # This must be class-scope, so all subclasses use the same one.
    def __init__(self):
        self.rateLimiter = RateLimiter()
        self.Proxy = IrcObjectProxy

    def configure(self, irc):
        fakeIrc = ConfigIrcProxy(irc)
        for args in conf.commandsOnStart:
            args = args[:]
            command = args.pop(0)
            if self.isCommand(command):
                #debug.printf('%s: %r' % (command, args))
                method = getattr(self, command)
                line = '%s %s' % (command, ' '.join(map(utils.dqrepr, args)))
                msg = ircmsgs.privmsg(fakeIrc.nick, line, fakeIrc.prefix)
                try:
                    world.startup = True
                    method(fakeIrc, msg, args)
                finally:
                    world.startup = False

    def __call__(self, irc, msg):
        irclib.IrcCallback.__call__(self, irc, msg)
        # Now, if there's anything in the rateLimiter...
        msg = self.rateLimiter.get()
        while msg:
            s = addressed(irc.nick, msg)
            try:
                args = tokenize(s)
                self.Proxy(irc, msg, args)
            except SyntaxError, e:
                irc.queueMsg(reply(msg, str(e)))
            msg = self.rateLimiter.get()

    def isCommand(self, methodName):
        # This function is ugly, but I don't want users to call methods like
        # doPrivmsg or __init__ or whatever, and this is good to stop them.
        if hasattr(self, methodName):
            method = getattr(self, methodName)
            if inspect.ismethod(method):
                code = method.im_func.func_code
                return inspect.getargs(code) == (self.commandArgs, None, None)
            else:
                return False
        else:
            return False

    def callCommand(self, f, irc, msg, args):
        if self.threaded:
            thread = CommandThread(f, irc, msg, args)
            thread.start()
            #debug.printf('Spawned new thread: %s' % thread)
        else:
            # Exceptions aren't caught here because IrcObjectProxy.finalEval
            # catches them and does The Right Thing.
            start = time.time()
            f(irc, msg, args)
            elapsed = time.time() - start
            funcname = f.im_func.func_name
            debug.msg('%s.%s took %s seconds' % \
                      (f.im_class.__name__, funcname, elapsed), 'verbose')

    _r = re.compile(r'^([^\s[]+)(?:\[|\s+|$)')
    def doPrivmsg(self, irc, msg):
        s = addressed(irc.nick, msg)
        #debug.printf('Privmsg.doPrivmsg: s == %r' % s)
        if s:
            recipient = msg.args[0]
            if ircdb.checkIgnored(msg.prefix, recipient):
                debug.msg('Privmsg.doPrivmsg: ignoring %s.' % msg.prefix)
                return
            m = self._r.match(s)
            if m and self.isCommand(canonicalName(m.group(1))):
                self.rateLimiter.put(msg)
                msg = self.rateLimiter.get()
                if msg:
                    try:
                        args = tokenize(s)
                        self.Proxy(irc, msg, args)
                    except SyntaxError, e:
                        irc.queueMsg(reply(msg, debug.exnToString(e)))


class IrcObjectProxyRegexp:
    def __init__(self, irc, *args):
        self.irc = irc

    def error(self, msg, s):
        self.reply(msg, 'Error: ' + s)

    def reply(self, msg, s):
        self.irc.queueMsg(reply(msg, s))

    def __getattr__(self, attr):
        return getattr(self.irc, attr)


class PrivmsgRegexp(Privmsg):
    """A class to allow a person to create regular expression callbacks.

    Much more primitive, but more flexible than the 'normal' method of using
    the Privmsg class and its lexer, PrivmsgRegexp allows you to write
    callbacks that aren't addressed to the bot, for instance.  There are, of
    course, several other possibilities.  Callbacks are registered with a
    string (the regular expression) and a function to be called (with the Irc
    object, the IrcMsg object, and the match object) when the regular
    expression matches.  Callbacks must have the signature (self, irc, msg,
    match) to be counted as such.

    A class-level flags attribute is used to determine what regexp flags to
    compile the regular expressions with.  By default, it's re.I, which means
    regular expressions are by default case-insensitive.

    If you have a standard command-type callback, though, Privmsg is a much
    better class to use, at the very least for consistency's sake, but also
    because it's much more easily coded and maintained.
    """
    threaded = False # Again, like Privmsg...
    flags = re.I
    onlyFirstMatch = False
    commandArgs = ['self', 'irc', 'msg', 'match']
    def __init__(self):
        Privmsg.__init__(self)
        self.Proxy = IrcObjectProxyRegexp
        self.res = []
        #for name, value in self.__class__.__dict__.iteritems():
        for name, value in self.__class__.__dict__.items():
            value = getattr(self, name)
            if self.isCommand(name):
                try:
                    r = re.compile(value.__doc__, self.flags)
                    self.res.append((r, value))
                except re.error, e:
                    s = '%s.%s has an invalid regexp %s: %s' % \
                        (self.__class__.__name__, name,
                         value.__doc__, debug.exnToString(e))
                    debug.msg(s)
        self.res.sort(lambda (r1, m1), (r2, m2): cmp(m1.__name__, m2.__name__))

    def doPrivmsg(self, irc, msg):
        if ircdb.checkIgnored(msg.prefix, msg.args[0]):
            debug.msg('PrivmsgRegexp.doPrivmsg: ignoring %s' % msg.args[0])
            return
        for (r, method) in self.res:
            m = r.search(msg.args[1])
            if m:
                self.rateLimiter.put(msg)
                msg = self.rateLimiter.get()
                if msg:
                    irc = IrcObjectProxyRegexp(irc)
                    self.callCommand(method, irc, msg, m)
                if self.onlyFirstMatch:
                    return


class PrivmsgCommandAndRegexp(Privmsg):
    """Same as Privmsg, except allows the user to also include regexp-based
    callbacks.  All regexp-based callbacks must be specified in a sets.Set
    (or list) attribute "regexps".
    """
    flags = re.I
    regexps = sets.Set()
    def __init__(self):
        Privmsg.__init__(self)
        self.res = []
        for name in self.regexps:
            method = getattr(self, name)
            r = re.compile(method.__doc__, self.flags)
            self.res.append((r, method))

    def doPrivmsg(self, irc, msg):
        if ircdb.checkIgnored(msg.prefix, msg.args[0]):
            return
        for (r, method) in self.res:
            m = r.search(msg.args[1])
            if m:
                self.rateLimiter.put(msg)
                msg = self.rateLimiter.get()
                if msg:
                    self.callCommand(method, IrcObjectProxyRegexp(irc), msg, m)
        s = addressed(irc.nick, msg)
        if s:
            m = self._r.match(s)
            if m and self.isCommand(canonicalName(m.group(1))):
                self.rateLimiter.put(msg)
                msg = self.rateLimiter.get()
                if msg:
                    args = tokenize(s)
                    self.Proxy(irc, msg, args)






# vim:set shiftwidth=4 tabstop=8 expandtab textwidth=78: