text: # coding=utf8
  """
  bot.py - Willie IRC Bot
  Copyright 2008, Sean B. Palmer, inamidst.com
  Copyright 2012, Edward Powell, http://embolalia.net
  Copyright © 2012, Elad Alfassa <elad@fedoraproject.org>
  
  Licensed under the Eiffel Forum License 2.
  
  http://willie.dftba.net/
  """
  from __future__ import unicode_literals
  from __future__ import print_function
  from __future__ import absolute_import
  
  import time
  import imp
  import os
  import re
  import sys
  import socket
  import threading
  
  from datetime import datetime
  from willie import tools
  import willie.irc as irc
  from willie.db import WillieDB
  from willie.tools import (stderr, Nick, PriorityQueue, released,
                            get_command_regexp, iteritems, itervalues)
  import willie.module as module
  if sys.version_info.major >= 3:
      unicode = str
      basestring = str
      py3 = True
  else:
      py3 = False
  
  
  class Willie(irc.Bot):
      NOLIMIT = module.NOLIMIT
  
      def __init__(self, config):
          irc.Bot.__init__(self, config.core)
          self.config = config
          """The ``Config`` for the current Willie instance."""
          self.doc = {}
          """
          A dictionary of command names to their docstring and example, if
          declared. The first item in a callable's commands list is used as the
          key in version *3.2* onward. Prior to *3.2*, the name of the function
          as declared in the source code was used.
          """
          self.stats = {}
          """
          A dictionary which maps a tuple of a function name and where it was
          used to the nuber of times it was used there.
          """
          self.times = {}
          """
          A dictionary mapping lower-case'd nicks to dictionaries which map
          funtion names to the time which they were last used by that nick.
          """
          self.acivity = {}
  
          self.server_capabilities = set()
          """A set containing the IRCv3 capabilities that the server supports.
  
          For servers that do not support IRCv3, this will be an empty set."""
          self.enabled_capabilities = set()
          """A set containing the IRCv3 capabilities that the bot has enabled."""
          self._cap_reqs = dict()
          """A dictionary of capability requests
  
          Maps the capability name to a list of tuples of the prefix ('-', '=',
          or ''), the name of the requesting module, and the function to call if
          the request is rejected."""
  
          self.privileges = dict()
          """A dictionary of channels to their users and privilege levels
  
          The value associated with each channel is a dictionary of Nicks to a
          bitwise integer value, determined by combining the appropriate constants
          from `module`."""
  
          self.db = WillieDB(config)
          if self.db.check_table('locales', ['name'], 'name'):
              self.settings = self.db.locales
              self.db.preferences = self.db.locales
          elif self.db.check_table('preferences', ['name'], 'name'):
              self.settings = self.db.preferences
          elif self.db.type is not None:
              self.db.add_table('preferences', ['name'], 'name')
              self.settings = self.db.preferences
  
          self.memory = tools.WillieMemory()
          """
          A thread-safe dict for storage of runtime data to be shared between
          modules. See `WillieMemory <#tools.Willie.WillieMemory>`_
          """
  
          self.scheduler = Willie.JobScheduler(self)
          self.scheduler.start()
  
          #Set up block lists
          #Default to empty
          if not self.config.core.nick_blocks:
              self.config.core.nick_blocks = []
          if not self.config.core.nick_blocks:
              self.config.core.host_blocks = []
          #Add nicks blocked under old scheme, if present
          if self.config.core.other_bots:
              nicks = self.config.core.get_list('nick_blocks')
              bots = self.config.core.get_list('other_bots')
              nicks.extend(bots)
              self.config.core.nick_blocks = nicks
              self.config.core.other_bots = False
              self.config.save()
  
          self.setup()
  
      class JobScheduler(threading.Thread):
  
          """Calls jobs assigned to it in steady intervals.
  
          JobScheduler is a thread that keeps track of Jobs and calls them every
          X seconds, where X is a property of the Job. It maintains jobs in a
          priority queue, where the next job to be called is always the first
          item.
          Thread safety is maintained with a mutex that is released during long
          operations, so methods add_job and clear_jobs can be safely called from
          the main thread.
  
          """
  
          min_reaction_time = 30.0  # seconds
          """How often should scheduler checks for changes in the job list."""
  
          def __init__(self, bot):
              """Requires bot as argument for logging."""
              threading.Thread.__init__(self)
              self.bot = bot
              self._jobs = PriorityQueue()
              # While PriorityQueue it self is thread safe, this mutex is needed
              # to stop old jobs being put into new queue after clearing the
              # queue.
              self._mutex = threading.Lock()
              # self.cleared is used for more fine grained locking.
              self._cleared = False
  
          def add_job(self, job):
              """Add a Job to the current job queue."""
              self._jobs.put(job)
  
          def clear_jobs(self):
              """Clear current Job queue and start fresh."""
              if self._jobs.empty():
                  # Guards against getting stuck waiting for self._mutex when
                  # thread is waiting for self._jobs to not be empty.
                  return
              with self._mutex:
                  self._cleared = True
                  self._jobs = PriorityQueue()
  
          def run(self):
              """Run forever."""
              while True:
                  try:
                      self._do_next_job()
                  except Exception:
                      # Modules exceptions are caught earlier, so this is a bit
                      # more serious. Options are to either stop the main thread
                      # or continue this thread and hope that it won't happen
                      # again.
                      self.bot.error()
                      # Sleep a bit to guard against busy-looping and filling
                      # the log with useless error messages.
                      time.sleep(10.0)  # seconds
  
          def _do_next_job(self):
              """Wait until there is a job and do it."""
              with self._mutex:
                  # Wait until the next job should be executed.
                  # This has to be a loop, because signals stop time.sleep().
                  while True:
                      job = self._jobs.peek()
                      difference = job.next_time - time.time()
                      duration = min(difference, self.min_reaction_time)
                      if duration <= 0:
                          break
                      with released(self._mutex):
                          time.sleep(duration)
  
                  self._cleared = False
                  job = self._jobs.get()
                  with released(self._mutex):
                      if job.func.thread:
                          t = threading.Thread(
                              target=self._call, args=(job.func,)
                          )
                          t.start()
                      else:
                          self._call(job.func)
                      job.next()
                  # If jobs were cleared during the call, don't put an old job
                  # into the new job queue.
                  if not self._cleared:
                      self._jobs.put(job)
  
          def _call(self, func):
              """Wrapper for collecting errors from modules."""
              # Willie.bot.call is way too specialized to be used instead.
              try:
                  func(self.bot)
              except Exception:
                  self.bot.error()
  
      class Job(object):
  
          """Hold information about when a function should be called next.
  
          Job is a simple structure that hold information about when a function
          should be called next.
          They can be put in a priority queue, in which case the Job that should
          be executed next is returned.
  
          Calling the method next modifies the Job object for the next time it
          should be executed. Current time is used to decide when the job should
          be executed next so it should only be called right after the function
          was called.
  
          """
  
          max_catchup = 5
          """
          This governs how much the scheduling of jobs is allowed
          to get behind before they are simply thrown out to avoid
          calling the same function too many times at once.
          """
  
          def __init__(self, interval, func):
              """Initialize Job.
  
              Args:
                  interval: number of seconds between calls to func
                  func: function to be called
  
              """
              self.next_time = time.time() + interval
              self.interval = interval
              self.func = func
  
          def next(self):
              """Update self.next_time with the assumption func was just called.
  
              Returns: A modified job object.
  
              """
              last_time = self.next_time
              current_time = time.time()
              delta = last_time + self.interval - current_time
  
              if last_time > current_time + self.interval:
                  # Clock appears to have moved backwards. Reset
                  # the timer to avoid waiting for the clock to
                  # catch up to whatever time it was previously.
                  self.next_time = current_time + self.interval
              elif delta < 0 and abs(delta) > self.interval * self.max_catchup:
                  # Execution of jobs is too far behind. Give up on
                  # trying to catch up and reset the time, so that
                  # will only be repeated a maximum of
                  # self.max_catchup times.
                  self.next_time = current_time - \
                      self.interval * self.max_catchup
              else:
                  self.next_time = last_time + self.interval
  
              return self
  
          def __cmp__(self, other):
              """Compare Job objects according to attribute next_time."""
              return self.next_time - other.next_time
  
          if py3:
              def __lt__(self, other):
                  return self.next_time < other.next_time
  
              def __gt__(self, other):
                  return self.next_time > other.next_time
  
          def __str__(self):
              """Return a string representation of the Job object.
  
              Example result:
                  <Job(2013-06-14 11:01:36.884000, 20s, <function upper at 0x02386BF0>)>
  
              """
              iso_time = str(datetime.fromtimestamp(self.next_time))
              return "<Job(%s, %ss, %s)>" % \
                  (iso_time, self.interval, self.func)
  
          def __iter__(self):
              """This is an iterator. Never stops though."""
              return self
  
      def setup(self):
          stderr("\nWelcome to Willie. Loading modules...\n\n")
          self.callables = set()
          self.shutdown_methods = set()
  
          filenames = self.config.enumerate_modules()
          # Coretasks is special. No custom user coretasks.
          this_dir = os.path.dirname(os.path.abspath(__file__))
          filenames['coretasks'] = os.path.join(this_dir, 'coretasks.py')
  
          modules = []
          error_count = 0
          for name, filename in iteritems(filenames):
              try:
                  module = imp.load_source(name, filename)
              except Exception as e:
                  error_count = error_count + 1
                  filename, lineno = tools.get_raising_file_and_line()
                  rel_path = os.path.relpath(filename, os.path.dirname(__file__))
                  raising_stmt = "%s:%d" % (rel_path, lineno)
                  stderr("Error loading %s: %s (%s)" % (name, e, raising_stmt))
              else:
                  try:
                      if hasattr(module, 'setup'):
                          module.setup(self)
                      self.register(vars(module))
                      modules.append(name)
                  except Exception as e:
                      error_count = error_count + 1
                      filename, lineno = tools.get_raising_file_and_line()
                      rel_path = os.path.relpath(
                          filename, os.path.dirname(__file__)
                      )
                      raising_stmt = "%s:%d" % (rel_path, lineno)
                      stderr("Error in %s setup procedure: %s (%s)"
                             % (name, e, raising_stmt))
  
          if modules:
              stderr('\n\nRegistered %d modules,' % (len(modules) - 1))
              stderr('%d modules failed to load\n\n' % error_count)
          else:
              stderr("Warning: Couldn't find any modules")
  
          self.bind_commands()
  
      @staticmethod
      def is_callable(obj):
          """Return true if object is a willie callable.
  
          Object must be both be callable and have hashable. Furthermore, it must
          have either "commands", "rule" or "interval" as attributes to mark it
          as a willie callable.
  
          """
          if not callable(obj):
              # Check is to help distinguish between willie callables and objects
              # which just happen to have parameter commands or rule.
              return False
          if (hasattr(obj, 'commands') or
                  hasattr(obj, 'rule') or
                  hasattr(obj, 'interval')):
              return True
          return False
  
      @staticmethod
      def is_shutdown(obj):
          """Return true if object is a willie shutdown method.
  
          Object must be both be callable and named shutdown.
  
          """
          if (callable(obj) and
                  hasattr(obj, "__name__")
                  and obj.__name__ == 'shutdown'):
              return True
          return False
  
      def register(self, variables):
          """Register all willie callables.
  
          With the ``__dict__`` attribute from a Willie module, update or add the
          trigger commands and rules, to allow the function to be triggered, and
          shutdown methods, to allow the modules to be notified when willie is
          quitting.
  
          """
          for obj in itervalues(variables):
              if self.is_callable(obj):
                  self.callables.add(obj)
              if self.is_shutdown(obj):
                  self.shutdown_methods.add(obj)
  
      def unregister(self, variables):
          """Unregister all willie callables in variables, and their bindings.
  
          When unloading a module, this ensures that the unloaded modules will
          not get called and that the objects can be garbage collected. Objects
          that have not been registered are ignored.
  
          Args:
          variables -- A list of callable objects from a willie module.
  
          """
  
          def remove_func(func, commands):
              """Remove all traces of func from commands."""
              for func_list in itervalues(commands):
                  if func in func_list:
                      func_list.remove(func)
  
          hostmask = "%s!%s@%s" % (self.nick, self.user, socket.gethostname())
          willie = self.WillieWrapper(self, irc.Origin(self, hostmask, [], {}))
          for obj in itervalues(variables):
              if obj in self.callables:
                  self.callables.remove(obj)
                  for commands in itervalues(self.commands):
                      remove_func(obj, commands)
              if obj in self.shutdown_methods:
                  try:
                      obj(willie)
                  except Exception as e:
                      stderr(
                          "Error calling shutdown method for module %s:%s" %
                          (obj.__module__, e)
                      )
                  self.shutdown_methods.remove(obj)
  
      def sub(self, pattern):
          """Replace any of the following special directives in a function's rule expression:
          $nickname -> the bot's nick
          $nick     -> the bot's nick followed by : or ,
          """
          nick = re.escape(self.nick)
  
          # These replacements have significant order
          subs = [('$nickname', r'{0}'.format(nick)),
                  ('$nick', r'{0}[,:]\s+'.format(nick)),
                  ]
          for directive, subpattern in subs:
              pattern = pattern.replace(directive, subpattern)
  
          return pattern
  
      def bind_commands(self):
          self.commands = {'high': {}, 'medium': {}, 'low': {}}
          self.scheduler.clear_jobs()
  
          def bind(priority, regexp, func):
              # Function name is no longer used for anything, as far as I know,
              # but we're going to keep it around anyway.
              if not hasattr(func, 'name'):
                  func.name = func.__name__
  
              def trim_docstring(doc):
                  """Clean up a docstring"""
                  if not doc:
                      return []
                  lines = doc.expandtabs().splitlines()
                  indent = sys.maxsize
                  for line in lines[1:]:
                      stripped = line.lstrip()
                      if stripped:
                          indent = min(indent, len(line) - len(stripped))
                  trimmed = [lines[0].strip()]
                  if indent < sys.maxsize:
                      for line in lines[1:]:
                          trimmed.append(line[indent:].rstrip())
                  while trimmed and not trimmed[-1]:
                      trimmed.pop()
                  while trimmed and not trimmed[0]:
                      trimmed.pop(0)
                  return trimmed
              doc = trim_docstring(func.__doc__)
  
              if hasattr(func, 'commands') and func.commands[0]:
                  example = None
                  if hasattr(func, 'example'):
                      if isinstance(func.example, basestring):
                          # Support old modules that add the attribute directly.
                          example = func.example
                      else:
                          # The new format is a list of dicts.
                          example = func.example[0]["example"]
                      example = example.replace('$nickname', str(self.nick))
                  if doc or example:
                      for command in func.commands:
                          self.doc[command] = (doc, example)
              self.commands[priority].setdefault(regexp, []).append(func)
  
          for func in self.callables:
              if not hasattr(func, 'unblockable'):
                  func.unblockable = False
  
              if not hasattr(func, 'priority'):
                  func.priority = 'medium'
  
              if not hasattr(func, 'thread'):
                  func.thread = True
  
              if not hasattr(func, 'event'):
                  func.event = ['PRIVMSG']
              else:
                  if type(func.event) is not list:
                      func.event = [func.event.upper()]
                  else:
                      func.event = [event.upper() for event in func.event]
  
              if not hasattr(func, 'rate'):
                  func.rate = 0
  
              if hasattr(func, 'rule'):
                  rules = func.rule
                  if isinstance(rules, basestring):
                      rules = [func.rule]
  
                  if isinstance(rules, list):
                      for rule in rules:
                          pattern = self.sub(rule)
                          flags = re.IGNORECASE
                          if rule.find("\n") != -1:
                              flags |= re.VERBOSE
                          regexp = re.compile(pattern, flags)
                          bind(func.priority, regexp, func)
  
                  elif isinstance(func.rule, tuple):
                      # 1) e.g. ('$nick', '(.*)')
                      if len(func.rule) == 2 and isinstance(func.rule[0], str):
                          prefix, pattern = func.rule
                          prefix = self.sub(prefix)
                          regexp = re.compile(prefix + pattern, re.I)
                          bind(func.priority, regexp, func)
  
                      # 2) e.g. (['p', 'q'], '(.*)')
                      elif len(func.rule) == 2 and \
                              isinstance(func.rule[0], list):
                          prefix = self.config.core.prefix
                          commands, pattern = func.rule
                          for command in commands:
                              command = r'(%s)\b(?: +(?:%s))?' % (
                                  command, pattern
                              )
                              regexp = re.compile(prefix + command, re.I)
                              bind(func.priority, regexp, func)
  
                      # 3) e.g. ('$nick', ['p', 'q'], '(.*)')
                      elif len(func.rule) == 3:
                          prefix, commands, pattern = func.rule
                          prefix = self.sub(prefix)
                          for command in commands:
                              command = r'(%s) +' % command
                              regexp = re.compile(
                                  prefix + command + pattern, re.I
                              )
                              bind(func.priority, regexp, func)
  
              if hasattr(func, 'commands'):
                  for command in func.commands:
                      prefix = self.config.core.prefix
                      regexp = get_command_regexp(prefix, command)
                      bind(func.priority, regexp, func)
  
              if hasattr(func, 'interval'):
                  for interval in func.interval:
                      job = Willie.Job(interval, func)
                      self.scheduler.add_job(job)
  
      class WillieWrapper(object):
          def __init__(self, willie, origin):
              object.__setattr__(self, 'bot', willie)
              object.__setattr__(self, 'origin', origin)
  
          def __dir__(self):
              classattrs = [attr for attr in self.__class__.__dict__
                            if not attr.startswith('__')]
              return list(self.__dict__) + classattrs + dir(self.bot)
  
          def say(self, string, max_messages=1):
              self.bot.msg(self.origin.sender, string, max_messages)
  
          def reply(self, string, notice=False):
              if isinstance(string, str) and not py3:
                  string = string.decode('utf8')
              if notice:
                  self.notice(
                      '%s: %s' % (self.origin.nick, string),
                      self.origin.sender
                  )
              else:
                  self.bot.msg(
                      self.origin.sender,
                      '%s: %s' % (self.origin.nick, string)
                  )
  
          def action(self, string, recipient=None):
              if recipient is None:
                  recipient = self.origin.sender
              self.bot.msg(recipient, '\001ACTION %s\001' % string)
  
          def notice(self, string, recipient=None):
              if recipient is None:
                  recipient = self.origin.sender
              self.write(('NOTICE', recipient), string)
  
          def __getattr__(self, attr):
              return getattr(self.bot, attr)
  
          def __setattr__(self, attr, value):
              return setattr(self.bot, attr, value)
  
      class Trigger(unicode):
          def __new__(cls, text, origin, bytes, match, event, args, self):
              s = unicode.__new__(cls, text)
  
              """Is trigger from a channel or in PM"""
              s.is_privmsg = origin.sender.is_nick()
  
              s.sender = origin.sender
              """
              The channel (or nick, in a private message) from which the
              message was sent.
              """
              s.hostmask = origin.hostmask
              """
              Hostmask of the person who sent the message in the form
              <nick>!<user>@<host>
              """
              s.user = origin.user
              """Local username of the person who sent the message"""
              s.nick = origin.nick
              """The ``Nick`` of the person who sent the message."""
              s.event = event
              """
              The IRC event (e.g. ``PRIVMSG`` or ``MODE``) which triggered the
              message."""
              s.bytes = bytes
              """
              The text which triggered the message. Equivalent to
              ``Trigger.group(0)``.
              """
              s.match = match
              """
              The regular expression ``MatchObject_`` for the triggering line.
              .. _MatchObject: http://docs.python.org/library/re.html#match-objects
              """
              s.group = match.group
              """The ``group`` function of the ``match`` attribute.
  
              See Python ``re_`` documentation for details."""
              s.groups = match.groups
              """The ``groups`` function of the ``match`` attribute.
  
              See Python ``re_`` documentation for details."""
              s.args = args
              """
              A tuple containing each of the arguments to an event. These are the
              strings passed between the event name and the colon. For example,
              setting ``mode -m`` on the channel ``#example``, args would be
              ``('#example', '-m')``
              """
              s.tags = origin.tags
              """A map of the IRCv3 message tags on the message.
  
              If the message had no tags, or the server does not support IRCv3
              message tags, this will be an empty dict."""
  
              def match_host_or_nick(pattern):
                  pattern = tools.get_hostmask_regex(pattern)
                  return bool(
                      pattern.match(origin.nick) or
                      pattern.match('@'.join((origin.nick, origin.host)))
                  )
  
              s.admin = any(match_host_or_nick(item)
                            for item in self.config.core.get_list('admins'))
              """
              True if the nick which triggered the command is in Willie's admin
              list as defined in the config file.
              """
              s.owner = match_host_or_nick(self.config.core.owner)
              s.admin = s.admin or s.owner
              s.host = origin.host
  
              if s.sender is not s.nick:  # no ops in PM
                  s.ops = self.ops.get(s.sender, [])
                  """
                  List of channel operators in the channel the message was
                  recived in
                  """
                  s.halfplus = self.halfplus.get(s.sender, [])
                  """
                  List of channel half-operators in the channel the message was
                  recived in
                  """
                  s.isop = (s.nick in s.ops or
                            s.nick in s.halfplus)
                  """True if the user is half-op or an op"""
                  s.voices = self.voices.get(s.sender, [])
                  """
                  List of channel operators in the channel the message was
                  recived in
                  """
                  s.isvoice = (s.nick in s.ops or
                               s.nick in s.halfplus or
                               s.nick in s.voices)
                  """True if the user is voiced, has op, or has half-op"""
              else:
                  s.isop = False
                  s.isvoice = False
                  s.ops = []
                  s.halfplus = []
                  s.voices = []
              return s
  
      def call(self, func, origin, willie, trigger):
          nick = trigger.nick
          if nick not in self.times:
              self.times[nick] = dict()
  
          if not trigger.admin and \
                  not func.unblockable and \
                  func.rate > 0 and \
                  func in self.times[nick]:
              timediff = time.time() - self.times[nick][func]
              if timediff < func.rate:
                  self.times[nick][func] = time.time()
                  self.debug(
                      __file__,
                      "%s prevented from using %s in %s: %d < %d" % (
                          trigger.nick, func.__name__, trigger.sender,
                          timediff, func.rate
                      ),
                      "verbose"
                  )
                  return
  
          try:
              exit_code = func(willie, trigger)
          except Exception:
              exit_code = None
              self.error(origin, trigger)
  
          if exit_code != module.NOLIMIT:
              self.times[nick][func] = time.time()
  
      def limit(self, origin, func):
          if origin.sender and not origin.sender.is_nick():
              if self.config.has_section('limit'):
                  limits = self.config.limit.get(origin.sender)
                  if limits and (func.__module__ not in limits):
                      return True
          return False
  
      def dispatch(self, origin, text, args):
          event, args = args[0], args[1:]
  
          wrapper = self.WillieWrapper(self, origin)
  
          if self.config.core.nick_blocks or self.config.core.host_blocks:
              nick_blocked = self._nick_blocked(origin.nick)
              host_blocked = self._host_blocked(origin.host)
          else:
              nick_blocked = host_blocked = None
  
          list_of_blocked_functions = []
          for priority in ('high', 'medium', 'low'):
              items = self.commands[priority].items()
  
              for regexp, funcs in items:
                  match = regexp.match(text)
                  if not match:
                      continue
                  trigger = self.Trigger(
                      text, origin, text, match, event, args, self
                  )
  
                  for func in funcs:
                      if (not trigger.admin and
                              not func.unblockable and
                              (nick_blocked or host_blocked)):
                          function_name = "%s.%s" % (
                              func.__module__, func.__name__
                          )
                          list_of_blocked_functions.append(function_name)
                          continue
  
                      if event not in func.event:
                          continue
                      if self.limit(origin, func):
                          continue
                      if func.thread:
                          targs = (func, origin, wrapper, trigger)
                          t = threading.Thread(target=self.call, args=targs)
                          t.start()
                      else:
                          self.call(func, origin, wrapper, trigger)
  
          if list_of_blocked_functions:
              if nick_blocked and host_blocked:
                  block_type = 'both'
              elif nick_blocked:
                  block_type = 'nick'
              else:
                  block_type = 'host'
              self.debug(
                  __file__,
                  "[%s]%s prevented from using %s." % (
                      block_type,
                      origin.nick,
                      ', '.join(list_of_blocked_functions)
                  ),
                  "verbose"
              )
  
      def _host_blocked(self, host):
          bad_masks = self.config.core.get_list('host_blocks')
          for bad_mask in bad_masks:
              bad_mask = bad_mask.strip()
              if not bad_mask:
                  continue
              if (re.match(bad_mask + '$', host, re.IGNORECASE) or
                      bad_mask == host):
                  return True
          return False
  
      def _nick_blocked(self, nick):
          bad_nicks = self.config.core.get_list('nick_blocks')
          for bad_nick in bad_nicks:
              bad_nick = bad_nick.strip()
              if not bad_nick:
                  continue
              if (re.match(bad_nick + '$', nick, re.IGNORECASE) or
                      Nick(bad_nick) == nick):
                  return True
          return False
  
      def debug(self, tag, text, level):
          """Sends an error to Willie's configured ``debug_target``.
  
          Args:
              tag - What the msg will be tagged as. It is recommended to pass
                  __file__ as the tag. If the file exists, a relative path is
                  used as the file. Otherwise the tag is used as it is.
  
              text - Body of the message.
  
              level - Either verbose, warning or always. Configuration option
                  config.verbose which levels are ignored.
  
          Returns: True if message was sent.
  
          """
          if not self.config.core.verbose:
              self.config.core.verbose = 'warning'
          if not self.config.core.debug_target:
              self.config.core.debug_target = 'stdio'
          debug_target = self.config.core.debug_target
          verbosity = self.config.core.verbose
  
          if os.path.exists(tag):
              tag = os.path.relpath(tag, os.path.dirname(__file__))
          debug_msg = "[%s] %s" % (tag, text)
  
          output_on = {
              'verbose': ['verbose'],
              'warning': ['verbose', 'warning'],
              'always': ['verbose', 'warning', 'always'],
          }
          if level in output_on and verbosity in output_on[level]:
              if debug_target == 'stdio':
                  print(debug_msg)
              else:
                  self.msg(debug_target, debug_msg)
              return True
          else:
              return False
  
      def _shutdown(self):
          stderr(
              'Calling shutdown for %d modules.' % (len(self.shutdown_methods),)
          )
  
          hostmask = "%s!%s@%s" % (self.nick, self.user, socket.gethostname())
          willie = self.WillieWrapper(self, irc.Origin(self, hostmask, [], {}))
          for shutdown_method in self.shutdown_methods:
              try:
                  stderr(
                      "calling %s.%s" % (
                          shutdown_method.__module__, shutdown_method.__name__,
                      )
                  )
                  shutdown_method(willie)
              except Exception as e:
                  stderr(
                      "Error calling shutdown method for module %s:%s" % (
                          shutdown_method.__module__, e
                      )
                  )
  
      def cap_req(self, module_name, capability, failure_callback):
          """Tell Willie to request a capability when it starts.
  
          By prefixing the capability with `-`, it will be ensured that the
          capability is not enabled. Simmilarly, by prefixing the capability with
          `=`, it will be ensured that the capability is enabled. Requiring and
          disabling is "first come, first served"; if one module requires a
          capability, and another prohibits it, this function will raise an
          exception in whichever module loads second. An exception will also be
          raised if the module is being loaded after the bot has already started,
          and the request would change the set of enabled capabilities.
  
          If the capability is not prefixed, and no other module prohibits it, it
          will be requested.  Otherwise, it will not be requested. Since
          capability requests that are not mandatory may be rejected by the
          server, as well as by other modules, a module which makes such a
          request should account for that possibility.
  
          The actual capability request to the server is handled after the
          completion of this function. In the event that the server denies a
          request, the `failure_callback` function will be called, if provided.
          The arguments will be a `Willie` object, and the capability which was
          rejected. This can be used to disable callables which rely on the
          capability.
  
          """
          #TODO raise better exceptions
          cap = capability[1:]
          prefix = capability[0]
  
          if prefix == '-':
              if self.connection_registered and cap in self.enabled_capabilities:
                  raise Exception('Can not change capabilities after server '
                                  'connection has been completed.')
              entry = self._cap_reqs.get(cap, [])
              if any((ent[0] != '-' for ent in entry)):
                  raise Exception('Capability conflict')
              entry.append((prefix, module_name, failure_callback))
              self._cap_reqs[cap] = entry
          else:
              if prefix != '=':
                  cap = capability
                  prefix = ''
              if self.connection_registered and (cap not in
                                                 self.enabled_capabilities):
                  raise Exception('Can not change capabilities after server '
                                  'connection has been completed.')
              entry = self._cap_reqs.get(cap, [])
              # Non-mandatory will callback at the same time as if the server
              # rejected it.
              if any((ent[0] == '-' for ent in entry)) and prefix == '=':
                  raise Exception('Capability conflict')
              entry.append((prefix, module_name, failure_callback))
              self._cap_reqs[cap] = entry
  