[user/henk/code/ruby/rbot.git] / lib / rbot / ircbot.rb

require 'thread'
require 'etc'
require 'fileutils'

$debug = false unless $debug
$daemonize = false unless $daemonize

def rawlog(code="", message=nil)
  if !code || code.empty?
    c = "  "
  else
    c = code.to_s[0,1].upcase + ":"
  end
  stamp = Time.now.strftime("%Y/%m/%d %H:%M:%S")
  message.to_s.each_line { |l|
    $stdout.puts "#{c} [#{stamp}] #{l}"
  }
  $stdout.flush
end

def log(message=nil)
  rawlog("", message)
end

def log_session_end
   log("\n=== #{botclass} session ended ===") if $daemonize
end

def debug(message=nil)
  rawlog("D", message) if $debug
end

def warning(message=nil)
  rawlog("W", message)
end

def error(message=nil)
  rawlog("E", message)
end

# The following global is used for the improved signal handling.
$interrupted = 0

# these first
require 'rbot/rbotconfig'
require 'rbot/config'
require 'rbot/utils'

require 'rbot/rfc2812'
require 'rbot/keywords'
require 'rbot/ircsocket'
require 'rbot/auth'
require 'rbot/timer'
require 'rbot/plugins'
require 'rbot/channel'
require 'rbot/message'
require 'rbot/language'
require 'rbot/dbhash'
require 'rbot/registry'
require 'rbot/httputil'

module Irc

# Main bot class, which manages the various components, receives messages,
# handles them or passes them to plugins, and contains core functionality.
class IrcBot
  # the bot's current nickname
  attr_reader :nick

  # the bot's IrcAuth data
  attr_reader :auth

  # the bot's BotConfig data
  attr_reader :config

  # the botclass for this bot (determines configdir among other things)
  attr_reader :botclass

  # used to perform actions periodically (saves configuration once per minute
  # by default)
  attr_reader :timer

  # bot's Language data
  attr_reader :lang

  # capabilities info for the server
  attr_reader :capabilities

  # channel info for channels the bot is in
  attr_reader :channels

  # bot's irc socket
  attr_reader :socket

  # bot's object registry, plugins get an interface to this for persistant
  # storage (hash interface tied to a bdb file, plugins use Accessors to store
  # and restore objects in their own namespaces.)
  attr_reader :registry

  # bot's plugins. This is an instance of class Plugins
  attr_reader :plugins

  # bot's httputil help object, for fetching resources via http. Sets up
  # proxies etc as defined by the bot configuration/environment
  attr_reader :httputil

  # create a new IrcBot with botclass +botclass+
  def initialize(botclass, params = {})
    # BotConfig for the core bot
    # TODO should we split socket stuff into ircsocket, etc?
    BotConfig.register BotConfigStringValue.new('server.name',
      :default => "localhost", :requires_restart => true,
      :desc => "What server should the bot connect to?",
      :wizard => true)
    BotConfig.register BotConfigIntegerValue.new('server.port',
      :default => 6667, :type => :integer, :requires_restart => true,
      :desc => "What port should the bot connect to?",
      :validate => Proc.new {|v| v > 0}, :wizard => true)
    BotConfig.register BotConfigStringValue.new('server.password',
      :default => false, :requires_restart => true,
      :desc => "Password for connecting to this server (if required)",
      :wizard => true)
    BotConfig.register BotConfigStringValue.new('server.bindhost',
      :default => false, :requires_restart => true,
      :desc => "Specific local host or IP for the bot to bind to (if required)",
      :wizard => true)
    BotConfig.register BotConfigIntegerValue.new('server.reconnect_wait',
      :default => 5, :validate => Proc.new{|v| v >= 0},
      :desc => "Seconds to wait before attempting to reconnect, on disconnect")
    BotConfig.register BotConfigFloatValue.new('server.sendq_delay',
      :default => 2.0, :validate => Proc.new{|v| v >= 0},
      :desc => "(flood prevention) the delay between sending messages to the server (in seconds)",
      :on_change => Proc.new {|bot, v| bot.socket.sendq_delay = v })
    BotConfig.register BotConfigIntegerValue.new('server.sendq_burst',
      :default => 4, :validate => Proc.new{|v| v >= 0},
      :desc => "(flood prevention) max lines to burst to the server before throttling. Most ircd's allow bursts of up 5 lines",
      :on_change => Proc.new {|bot, v| bot.socket.sendq_burst = v })
    BotConfig.register BotConfigStringValue.new('server.byterate',
      :default => "400/2", :validate => Proc.new{|v| v.match(/\d+\/\d/)},
      :desc => "(flood prevention) max bytes/seconds rate to send the server. Most ircd's have limits of 512 bytes/2 seconds",
      :on_change => Proc.new {|bot, v| bot.socket.byterate = v })
    BotConfig.register BotConfigIntegerValue.new('server.ping_timeout',
      :default => 30, :validate => Proc.new{|v| v >= 0},
      :on_change => Proc.new {|bot, v| bot.start_server_pings},
      :desc => "reconnect if server doesn't respond to PING within this many seconds (set to 0 to disable)")

    BotConfig.register BotConfigStringValue.new('irc.nick', :default => "rbot",
      :desc => "IRC nickname the bot should attempt to use", :wizard => true,
      :on_change => Proc.new{|bot, v| bot.sendq "NICK #{v}" })
    BotConfig.register BotConfigStringValue.new('irc.user', :default => "rbot",
      :requires_restart => true,
      :desc => "local user the bot should appear to be", :wizard => true)
    BotConfig.register BotConfigArrayValue.new('irc.join_channels',
      :default => [], :wizard => true,
      :desc => "What channels the bot should always join at startup. List multiple channels using commas to separate. If a channel requires a password, use a space after the channel name. e.g: '#chan1, #chan2, #secretchan secritpass, #chan3'")
    BotConfig.register BotConfigArrayValue.new('irc.ignore_users',
      :default => [], 
      :desc => "Which users to ignore input from. This is mainly to avoid bot-wars triggered by creative people")

    BotConfig.register BotConfigIntegerValue.new('core.save_every',
      :default => 60, :validate => Proc.new{|v| v >= 0},
      # TODO change timer via on_change proc
      :desc => "How often the bot should persist all configuration to disk (in case of a server crash, for example)")
      # BotConfig.register BotConfigBooleanValue.new('core.debug',
      #   :default => false, :requires_restart => true,
      #   :on_change => Proc.new { |v|
      #     debug ((v ? "Enabling" : "Disabling") + " debug output.")
      #     $debug = v
      #     debug (($debug ? "Enabled" : "Disabled") + " debug output.")
      #   },
      #   :desc => "Should the bot produce debug output?")
    BotConfig.register BotConfigBooleanValue.new('core.run_as_daemon',
      :default => false, :requires_restart => true,
      :desc => "Should the bot run as a daemon?")
    BotConfig.register BotConfigStringValue.new('core.logfile',
      :default => false, :requires_restart => true,
      :desc => "Name of the logfile to which console messages will be redirected when the bot is run as a daemon")

    @argv = params[:argv]

    unless FileTest.directory? Config::datadir
      error "data directory '#{Config::datadir}' not found, did you setup.rb?"
      exit 2
    end

    unless botclass and not botclass.empty?
      # We want to find a sensible default.
      #  * On POSIX systems we prefer ~/.rbot for the effective uid of the process
      #  * On Windows (at least the NT versions) we want to put our stuff in the
      #    Application Data folder.
      # We don't use any particular O/S detection magic, exploiting the fact that
      # Etc.getpwuid is nil on Windows
      if Etc.getpwuid(Process::Sys.geteuid)
        botclass = Etc.getpwuid(Process::Sys.geteuid)[:dir].dup
      else
        if ENV.has_key?('APPDATA')
          botclass = ENV['APPDATA'].dup
          botclass.gsub!("\\","/")
        end
      end
      botclass += "/.rbot"
    end
    botclass = File.expand_path(botclass)
    @botclass = botclass.gsub(/\/$/, "")

    unless FileTest.directory? botclass
      log "no #{botclass} directory found, creating from templates.."
      if FileTest.exist? botclass
        error "file #{botclass} exists but isn't a directory"
        exit 2
      end
      FileUtils.cp_r Config::datadir+'/templates', botclass
    end

    Dir.mkdir("#{botclass}/logs") unless File.exist?("#{botclass}/logs")
    Dir.mkdir("#{botclass}/registry") unless File.exist?("#{botclass}/registry")

    @ping_timer = nil
    @pong_timer = nil
    @last_ping = nil
    @startup_time = Time.new
    @config = BotConfig.new(self)
    # background self after botconfig has a chance to run wizard
    @logfile = @config['core.logfile']
    if @logfile.class!=String || @logfile.empty?
      @logfile = File.basename(botclass)+".log"
    end
    if @config['core.run_as_daemon']
      $daemonize = true
    end
    # See http://blog.humlab.umu.se/samuel/archives/000107.html
    # for the backgrounding code 
    if $daemonize
      begin
        exit if fork
        Process.setsid
        exit if fork
      rescue NotImplementedError
        warning "Could not background, fork not supported"
      rescue => e
        warning "Could not background. #{e.inspect}"
      end
      Dir.chdir botclass
      # File.umask 0000                # Ensure sensible umask. Adjust as needed.
      log "Redirecting standard input/output/error"
      begin
        STDIN.reopen "/dev/null"
      rescue Errno::ENOENT
        # On Windows, there's not such thing as /dev/null
        STDIN.reopen "NUL"
      end
      STDOUT.reopen @logfile, "a"
      STDERR.reopen STDOUT
      log "\n=== #{botclass} session started ==="
    end

    @timer = Timer::Timer.new(1.0) # only need per-second granularity
    @registry = BotRegistry.new self
    @timer.add(@config['core.save_every']) { save } if @config['core.save_every']
    @channels = Hash.new
    @logs = Hash.new
    @httputil = Utils::HttpUtil.new(self)
    @lang = Language::Language.new(@config['core.language'])
    @keywords = Keywords.new(self)
    @auth = IrcAuth.new(self)

    Dir.mkdir("#{botclass}/plugins") unless File.exist?("#{botclass}/plugins")
    @plugins = Plugins::Plugins.new(self, ["#{botclass}/plugins"])

    @socket = IrcSocket.new(@config['server.name'], @config['server.port'], @config['server.bindhost'], @config['server.sendq_delay'], @config['server.sendq_burst'])
    @nick = @config['irc.nick']

    @client = IrcClient.new
    @client[:isupport] = proc { |data|
      if data[:capab]
        sendq "CAPAB IDENTIFY-MSG"
      end
    }
    @client[:datastr] = proc { |data|
      debug data.inspect
      if data[:text] == "IDENTIFY-MSG"
        @capabilities["identify-msg".to_sym] = true
      else
        debug "Not handling RPL_DATASTR #{data[:servermessage]}"
      end
    }
    @client[:privmsg] = proc { |data|
      message = PrivMessage.new(self, data[:source], data[:target], data[:message])
      onprivmsg(message)
    }
    @client[:notice] = proc { |data|
      message = NoticeMessage.new(self, data[:source], data[:target], data[:message])
      # pass it off to plugins that want to hear everything
      @plugins.delegate "listen", message
    }
    @client[:motd] = proc { |data|
      data[:motd].each_line { |line|
        irclog "MOTD: #{line}", "server"
      }
    }
    @client[:nicktaken] = proc { |data|
      nickchg "#{data[:nick]}_"
      @plugins.delegate "nicktaken", data[:nick]
    }
    @client[:badnick] = proc {|data|
      warning "bad nick (#{data[:nick]})"
    }
    @client[:ping] = proc {|data|
      @socket.queue "PONG #{data[:pingid]}"
    }
    @client[:pong] = proc {|data|
      @last_ping = nil
    }
    @client[:nick] = proc {|data|
      sourcenick = data[:sourcenick]
      nick = data[:nick]
      m = NickMessage.new(self, data[:source], data[:sourcenick], data[:nick])
      if(sourcenick == @nick)
        debug "my nick is now #{nick}"
        @nick = nick
      end
      @channels.each {|k,v|
        if(v.users.has_key?(sourcenick))
          irclog "@ #{sourcenick} is now known as #{nick}", k
          v.users[nick] = v.users[sourcenick]
          v.users.delete(sourcenick)
        end
      }
      @plugins.delegate("listen", m)
      @plugins.delegate("nick", m)
    }
    @client[:quit] = proc {|data|
      source = data[:source]
      sourcenick = data[:sourcenick]
      sourceurl = data[:sourceaddress]
      message = data[:message]
      m = QuitMessage.new(self, data[:source], data[:sourcenick], data[:message])
      if(data[:sourcenick] =~ /#{Regexp.escape(@nick)}/i)
      else
        @channels.each {|k,v|
          if(v.users.has_key?(sourcenick))
            irclog "@ Quit: #{sourcenick}: #{message}", k
            v.users.delete(sourcenick)
          end
        }
      end
      @plugins.delegate("listen", m)
      @plugins.delegate("quit", m)
    }
    @client[:mode] = proc {|data|
      source = data[:source]
      sourcenick = data[:sourcenick]
      sourceurl = data[:sourceaddress]
      channel = data[:channel]
      targets = data[:targets]
      modestring = data[:modestring]
      irclog "@ Mode #{modestring} #{targets} by #{sourcenick}", channel
    }
    @client[:welcome] = proc {|data|
      irclog "joined server #{data[:source]} as #{data[:nick]}", "server"
      debug "I think my nick is #{@nick}, server thinks #{data[:nick]}"
      if data[:nick] && data[:nick].length > 0
        @nick = data[:nick]
      end

      @plugins.delegate("connect")

      @config['irc.join_channels'].each {|c|
        debug "autojoining channel #{c}"
        if(c =~ /^(\S+)\s+(\S+)$/i)
          join $1, $2
        else
          join c if(c)
        end
      }
    }
    @client[:join] = proc {|data|
      m = JoinMessage.new(self, data[:source], data[:channel], data[:message])
      onjoin(m)
    }
    @client[:part] = proc {|data|
      m = PartMessage.new(self, data[:source], data[:channel], data[:message])
      onpart(m)
    }
    @client[:kick] = proc {|data|
      m = KickMessage.new(self, data[:source], data[:target],data[:channel],data[:message])
      onkick(m)
    }
    @client[:invite] = proc {|data|
      if(data[:target] =~ /^#{Regexp.escape(@nick)}$/i)
        join data[:channel] if (@auth.allow?("join", data[:source], data[:sourcenick]))
      end
    }
    @client[:changetopic] = proc {|data|
      channel = data[:channel]
      sourcenick = data[:sourcenick]
      topic = data[:topic]
      timestamp = data[:unixtime] || Time.now.to_i
      if(sourcenick == @nick)
        irclog "@ I set topic \"#{topic}\"", channel
      else
        irclog "@ #{sourcenick} set topic \"#{topic}\"", channel
      end
      m = TopicMessage.new(self, data[:source], data[:channel], timestamp, data[:topic])

      ontopic(m)
      @plugins.delegate("listen", m)
      @plugins.delegate("topic", m)
    }
    @client[:topic] = @client[:topicinfo] = proc {|data|
      channel = data[:channel]
      m = TopicMessage.new(self, data[:source], data[:channel], data[:unixtime], data[:topic])
        ontopic(m)
    }
    @client[:names] = proc {|data|
      channel = data[:channel]
      users = data[:users]
      unless(@channels[channel])
        warning "got names for channel '#{channel}' I didn't think I was in\n"
        # exit 2
      end
      @channels[channel].users.clear
      users.each {|u|
        @channels[channel].users[u[0].sub(/^[@&~+]/, '')] = ["mode", u[1]]
      }
      @plugins.delegate "names", data[:channel], data[:users]
    }
    @client[:unknown] = proc {|data|
      #debug "UNKNOWN: #{data[:serverstring]}"
      irclog data[:serverstring], ".unknown"
    }
  end

  def got_sig(sig)
    debug "received #{sig}, queueing quit"
    $interrupted += 1
    debug "interrupted #{$interrupted} times"
    if $interrupted >= 5
      debug "drastic!"
      log_session_end
      exit 2
    elsif $interrupted >= 3
      debug "quitting"
      quit
    end
  end

  # connect the bot to IRC
  def connect
    begin
      trap("SIGINT") { got_sig("SIGINT") }
      trap("SIGTERM") { got_sig("SIGTERM") }
      trap("SIGHUP") { got_sig("SIGHUP") }
    rescue ArgumentError => e
      debug "failed to trap signals (#{e.inspect}): running on Windows?"
    rescue => e
      debug "failed to trap signals: #{e.inspect}"
    end
    begin
      quit if $interrupted > 0
      @socket.connect
    rescue => e
      raise e.class, "failed to connect to IRC server at #{@config['server.name']} #{@config['server.port']}: " + e
    end
    @socket.emergency_puts "PASS " + @config['server.password'] if @config['server.password']
    @socket.emergency_puts "NICK #{@nick}\nUSER #{@config['irc.user']} 4 #{@config['server.name']} :Ruby bot. (c) Tom Gilbert"
    @capabilities = Hash.new
    start_server_pings
  end

  # begin event handling loop
  def mainloop
    while true
      begin
        quit if $interrupted > 0
        connect
        @timer.start

        while @socket.connected?
          if @socket.select
            break unless reply = @socket.gets
            @client.process reply
          end
          quit if $interrupted > 0
        end

      # I despair of this. Some of my users get "connection reset by peer"
      # exceptions that ARENT SocketError's. How am I supposed to handle
      # that?
      rescue SystemExit
        log_session_end
        exit 0
      rescue Errno::ETIMEDOUT, TimeoutError, SocketError => e
        error "network exception: #{e.class}: #{e}"
        debug e.backtrace.join("\n")
      rescue BDB::Fatal => e
        error "fatal bdb error: #{e.class}: #{e}"
        error e.backtrace.join("\n")
        DBTree.stats
        restart("Oops, we seem to have registry problems ...")
      rescue Exception => e
        error "non-net exception: #{e.class}: #{e}"
        error e.backtrace.join("\n")
      rescue => e
        error "unexpected exception: #{e.class}: #{e}"
        error e.backtrace.join("\n")
        log_session_end
        exit 2
      end

      stop_server_pings
      @channels.clear
      if @socket.connected?
        @socket.clearq
        @socket.shutdown
      end

      log "disconnected"

      quit if $interrupted > 0

      log "waiting to reconnect"
      sleep @config['server.reconnect_wait']
    end
  end

  # type:: message type
  # where:: message target
  # message:: message text
  # send message +message+ of type +type+ to target +where+
  # Type can be PRIVMSG, NOTICE, etc, but those you should really use the
  # relevant say() or notice() methods. This one should be used for IRCd
  # extensions you want to use in modules.
  def sendmsg(type, where, message, chan=nil, ring=0)
    # limit it according to the byterate, splitting the message
    # taking into consideration the actual message length
    # and all the extra stuff
    # TODO allow something to do for commands that produce too many messages
    # TODO example: math 10**10000
    left = @socket.bytes_per - type.length - where.length - 4
    begin
      if(left >= message.length)
        sendq "#{type} #{where} :#{message}", chan, ring
        log_sent(type, where, message)
        return
      end
      line = message.slice!(0, left)
      lastspace = line.rindex(/\s+/)
      if(lastspace)
        message = line.slice!(lastspace, line.length) + message
        message.gsub!(/^\s+/, "")
      end
      sendq "#{type} #{where} :#{line}", chan, ring
      log_sent(type, where, line)
    end while(message.length > 0)
  end

  # queue an arbitraty message for the server
  def sendq(message="", chan=nil, ring=0)
    # temporary
    @socket.queue(message, chan, ring)
  end

  # send a notice message to channel/nick +where+
  def notice(where, message, mchan=nil, mring=-1)
    if mchan == ""
      chan = where
    else
      chan = mchan
    end
    if mring < 0
      if where =~ /^#/
        ring = 2
      else
        ring = 1
      end
    else
      ring = mring
    end
    message.each_line { |line|
      line.chomp!
      next unless(line.length > 0)
      sendmsg "NOTICE", where, line, chan, ring
    }
  end

  # say something (PRIVMSG) to channel/nick +where+
  def say(where, message, mchan="", mring=-1)
    if mchan == ""
      chan = where
    else
      chan = mchan
    end
    if mring < 0
      if where =~ /^#/
        ring = 2
      else
        ring = 1
      end
    else
      ring = mring
    end
    message.to_s.gsub(/[\r\n]+/, "\n").each_line { |line|
      line.chomp!
      next unless(line.length > 0)
      unless((where =~ /^#/) && (@channels.has_key?(where) && @channels[where].quiet))
        sendmsg "PRIVMSG", where, line, chan, ring 
      end
    }
  end

  # perform a CTCP action with message +message+ to channel/nick +where+
  def action(where, message, mchan="", mring=-1)
    if mchan == ""
      chan = where
    else
      chan = mchan
    end
    if mring < 0
      if where =~ /^#/
        ring = 2
      else
        ring = 1
      end
    else
      ring = mring
    end
    sendq "PRIVMSG #{where} :\001ACTION #{message}\001", chan, ring
    if(where =~ /^#/)
      irclog "* #{@nick} #{message}", where
    elsif (where =~ /^(\S*)!.*$/)
      irclog "* #{@nick}[#{where}] #{message}", $1
    else
      irclog "* #{@nick}[#{where}] #{message}", where
    end
  end

  # quick way to say "okay" (or equivalent) to +where+
  def okay(where)
    say where, @lang.get("okay")
  end

  # log IRC-related message +message+ to a file determined by +where+.
  # +where+ can be a channel name, or a nick for private message logging
  def irclog(message, where="server")
    message = message.chomp
    stamp = Time.now.strftime("%Y/%m/%d %H:%M:%S")
    where = where.gsub(/[:!?$*()\/\\<>|"']/, "_")
    unless(@logs.has_key?(where))
      @logs[where] = File.new("#{@botclass}/logs/#{where}", "a")
      @logs[where].sync = true
    end
    @logs[where].puts "[#{stamp}] #{message}"
    #debug "[#{stamp}] <#{where}> #{message}"
  end

  # set topic of channel +where+ to +topic+
  def topic(where, topic)
    sendq "TOPIC #{where} :#{topic}", where, 2
  end

  # disconnect from the server and cleanup all plugins and modules
  def shutdown(message = nil)
    debug "Shutting down ..."
    ## No we don't restore them ... let everything run through
    # begin
    #   trap("SIGINT", "DEFAULT")
    #   trap("SIGTERM", "DEFAULT")
    #   trap("SIGHUP", "DEFAULT")
    # rescue => e
    #   debug "failed to restore signals: #{e.inspect}\nProbably running on windows?"
    # end
    message = @lang.get("quit") if (message.nil? || message.empty?)
    if @socket.connected?
      debug "Clearing socket"
      @socket.clearq
      debug "Sending quit message"
      @socket.emergency_puts "QUIT :#{message}"
      debug "Flushing socket"
      @socket.flush
      debug "Shutting down socket"
      @socket.shutdown
    end
    debug "Logging quits"
    @channels.each_value {|v|
      irclog "@ quit (#{message})", v.name
    }
    debug "Saving"
    save
    debug "Cleaning up"
    @plugins.cleanup
    # debug "Closing registries"
    # @registry.close
    debug "Cleaning up the db environment"
    DBTree.cleanup_env
    log "rbot quit (#{message})"
  end

  # message:: optional IRC quit message
  # quit IRC, shutdown the bot
  def quit(message=nil)
    begin
      shutdown(message)
    ensure
      log_session_end
      exit 0
    end
  end

  # totally shutdown and respawn the bot
  def restart(message = false)
    msg = message ? message : "restarting, back in #{@config['server.reconnect_wait']}..."
    shutdown(msg)
    sleep @config['server.reconnect_wait']
    # now we re-exec
    # Note, this fails on Windows
    exec($0, *@argv)
  end

  # call the save method for bot's config, keywords, auth and all plugins
  def save
    @config.save
    @keywords.save
    @auth.save
    @plugins.save
    DBTree.cleanup_logs
  end

  # call the rescan method for the bot's lang, keywords and all plugins
  def rescan
    @lang.rescan
    @plugins.rescan
    @keywords.rescan
  end

  # channel:: channel to join
  # key::     optional channel key if channel is +s
  # join a channel
  def join(channel, key=nil)
    if(key)
      sendq "JOIN #{channel} :#{key}", channel, 2
    else
      sendq "JOIN #{channel}", channel, 2
    end
  end

  # part a channel
  def part(channel, message="")
    sendq "PART #{channel} :#{message}", channel, 2
  end

  # attempt to change bot's nick to +name+
  def nickchg(name)
      sendq "NICK #{name}"
  end

  # changing mode
  def mode(channel, mode, target)
      sendq "MODE #{channel} #{mode} #{target}", channel, 2
  end

  # m::     message asking for help
  # topic:: optional topic help is requested for
  # respond to online help requests
  def help(topic=nil)
    topic = nil if topic == ""
    case topic
    when nil
      helpstr = "help topics: core, auth, keywords"
      helpstr += @plugins.helptopics
      helpstr += " (help <topic> for more info)"
    when /^core$/i
      helpstr = corehelp
    when /^core\s+(.+)$/i
      helpstr = corehelp $1
    when /^auth$/i
      helpstr = @auth.help
    when /^auth\s+(.+)$/i
      helpstr = @auth.help $1
    when /^keywords$/i
      helpstr = @keywords.help
    when /^keywords\s+(.+)$/i
      helpstr = @keywords.help $1
    else
      unless(helpstr = @plugins.help(topic))
        helpstr = "no help for topic #{topic}"
      end
    end
    return helpstr
  end

  # returns a string describing the current status of the bot (uptime etc)
  def status
    secs_up = Time.new - @startup_time
    uptime = Utils.secs_to_string secs_up
    # return "Uptime #{uptime}, #{@plugins.length} plugins active, #{@registry.length} items stored in registry, #{@socket.lines_sent} lines sent, #{@socket.lines_received} received."
    return "Uptime #{uptime}, #{@plugins.length} plugins active, #{@socket.lines_sent} lines sent, #{@socket.lines_received} received."
  end

  # we'll ping the server every 30 seconds or so, and expect a response
  # before the next one come around..
  def start_server_pings
    stop_server_pings
    return unless @config['server.ping_timeout'] > 0
    # we want to respond to a hung server within 30 secs or so
    @ping_timer = @timer.add(30) {
      @last_ping = Time.now
      @socket.queue "PING :rbot"
    }
    @pong_timer = @timer.add(10) {
      unless @last_ping.nil?
        diff = Time.now - @last_ping
        unless diff < @config['server.ping_timeout']
          debug "no PONG from server for #{diff} seconds, reconnecting"
          begin
            @socket.shutdown
          rescue
            debug "couldn't shutdown connection (already shutdown?)"
          end
          @last_ping = nil
          raise TimeoutError, "no PONG from server in #{diff} seconds"
        end
      end
    }
  end

  def stop_server_pings
    @last_ping = nil
    # stop existing timers if running
    unless @ping_timer.nil?
      @timer.remove @ping_timer
      @ping_timer = nil
    end
    unless @pong_timer.nil?
      @timer.remove @pong_timer
      @pong_timer = nil
    end
  end

  private

  # handle help requests for "core" topics
  def corehelp(topic="")
    case topic
      when "quit"
        return "quit [<message>] => quit IRC with message <message>"
      when "restart"
        return "restart => completely stop and restart the bot (including reconnect)"
      when "join"
        return "join <channel> [<key>] => join channel <channel> with secret key <key> if specified. #{@nick} also responds to invites if you have the required access level"
      when "part"
        return "part <channel> => part channel <channel>"
      when "hide"
        return "hide => part all channels"
      when "save"
        return "save => save current dynamic data and configuration"
      when "rescan"
        return "rescan => reload modules and static facts"
      when "nick"
        return "nick <nick> => attempt to change nick to <nick>"
      when "say"
        return "say <channel>|<nick> <message> => say <message> to <channel> or in private message to <nick>"
      when "action"
        return "action <channel>|<nick> <message> => does a /me <message> to <channel> or in private message to <nick>"
        #       when "topic"
        #         return "topic <channel> <message> => set topic of <channel> to <message>"
      when "quiet"
        return "quiet [in here|<channel>] => with no arguments, stop speaking in all channels, if \"in here\", stop speaking in this channel, or stop speaking in <channel>"
      when "talk"
        return "talk [in here|<channel>] => with no arguments, resume speaking in all channels, if \"in here\", resume speaking in this channel, or resume speaking in <channel>"
      when "version"
        return "version => describes software version"
      when "botsnack"
        return "botsnack => reward #{@nick} for being good"
      when "hello"
        return "hello|hi|hey|yo [#{@nick}] => greet the bot"
      else
        return "Core help topics: quit, restart, config, join, part, hide, save, rescan, nick, say, action, topic, quiet, talk, version, botsnack, hello"
    end
  end

  # handle incoming IRC PRIVMSG +m+
  def onprivmsg(m)
    # log it first
    if(m.action?)
      if(m.private?)
        irclog "* [#{m.sourcenick}(#{m.sourceaddress})] #{m.message}", m.sourcenick
      else
        irclog "* #{m.sourcenick} #{m.message}", m.target
      end
    else
      if(m.public?)
        irclog "<#{m.sourcenick}> #{m.message}", m.target
      else
        irclog "[#{m.sourcenick}(#{m.sourceaddress})] #{m.message}", m.sourcenick
      end
    end

    @config['irc.ignore_users'].each { |mask| return if Irc.netmaskmatch(mask,m.source) }

    # pass it off to plugins that want to hear everything
    @plugins.delegate "listen", m

    if(m.private? && m.message =~ /^\001PING\s+(.+)\001/)
      notice m.sourcenick, "\001PING #$1\001"
      irclog "@ #{m.sourcenick} pinged me"
      return
    end

    if(m.address?)
      delegate_privmsg(m)
      case m.message
        when (/^join\s+(\S+)\s+(\S+)$/i)
          join $1, $2 if(@auth.allow?("join", m.source, m.replyto))
        when (/^join\s+(\S+)$/i)
          join $1 if(@auth.allow?("join", m.source, m.replyto))
        when (/^part$/i)
          part m.target if(m.public? && @auth.allow?("join", m.source, m.replyto))
        when (/^part\s+(\S+)$/i)
          part $1 if(@auth.allow?("join", m.source, m.replyto))
        when (/^quit(?:\s+(.*))?$/i)
          quit $1 if(@auth.allow?("quit", m.source, m.replyto))
        when (/^restart(?:\s+(.*))?$/i)
          restart $1 if(@auth.allow?("quit", m.source, m.replyto))
        when (/^hide$/i)
          join 0 if(@auth.allow?("join", m.source, m.replyto))
        when (/^save$/i)
          if(@auth.allow?("config", m.source, m.replyto))
            save
            m.okay
          end
        when (/^nick\s+(\S+)$/i)
          nickchg($1) if(@auth.allow?("nick", m.source, m.replyto))
        when (/^say\s+(\S+)\s+(.*)$/i)
          say $1, $2 if(@auth.allow?("say", m.source, m.replyto))
        when (/^action\s+(\S+)\s+(.*)$/i)
          action $1, $2 if(@auth.allow?("say", m.source, m.replyto))
          # when (/^topic\s+(\S+)\s+(.*)$/i)
          #   topic $1, $2 if(@auth.allow?("topic", m.source, m.replyto))
        when (/^mode\s+(\S+)\s+(\S+)\s+(.*)$/i)
          mode $1, $2, $3 if(@auth.allow?("mode", m.source, m.replyto))
        when (/^ping$/i)
          say m.replyto, "pong"
        when (/^rescan$/i)
          if(@auth.allow?("config", m.source, m.replyto))
            m.reply "Saving ..."
            save
            m.reply "Rescanning ..."
            rescan
            m.okay
          end
        when (/^quiet$/i)
          if(auth.allow?("talk", m.source, m.replyto))
            m.okay
            @channels.each_value {|c| c.quiet = true }
          end
        when (/^quiet in (\S+)$/i)
          where = $1
          if(auth.allow?("talk", m.source, m.replyto))
            m.okay
            where.gsub!(/^here$/, m.target) if m.public?
            @channels[where].quiet = true if(@channels.has_key?(where))
          end
        when (/^talk$/i)
          if(auth.allow?("talk", m.source, m.replyto))
            @channels.each_value {|c| c.quiet = false }
            m.okay
          end
        when (/^talk in (\S+)$/i)
          where = $1
          if(auth.allow?("talk", m.source, m.replyto))
            where.gsub!(/^here$/, m.target) if m.public?
            @channels[where].quiet = false if(@channels.has_key?(where))
            m.okay
          end
        when (/^status\??$/i)
          m.reply status if auth.allow?("status", m.source, m.replyto)
        when (/^registry stats$/i)
          if auth.allow?("config", m.source, m.replyto)
            m.reply @registry.stat.inspect
          end
        when (/^(help\s+)?config(\s+|$)/)
          @config.privmsg(m)
        when (/^(version)|(introduce yourself)$/i)
          say m.replyto, "I'm a v. #{$version} rubybot, (c) Tom Gilbert - http://linuxbrit.co.uk/rbot/"
        when (/^help(?:\s+(.*))?$/i)
          say m.replyto, help($1)
          #TODO move these to a "chatback" plugin
        when (/^(botsnack|ciggie)$/i)
          say m.replyto, @lang.get("thanks_X") % m.sourcenick if(m.public?)
          say m.replyto, @lang.get("thanks") if(m.private?)
        when (/^(hello|howdy|hola|salut|bonjour|sup|niihau|hey|hi(\W|$)|yo(\W|$)).*/i)
          say m.replyto, @lang.get("hello_X") % m.sourcenick if(m.public?)
          say m.replyto, @lang.get("hello") if(m.private?)
      end
    else
      # stuff to handle when not addressed
      case m.message
        when (/^\s*(hello|howdy|hola|salut|bonjour|sup|niihau|hey|hi|yo(\W|$))[\s,-.]+#{Regexp.escape(@nick)}$/i)
          say m.replyto, @lang.get("hello_X") % m.sourcenick
        when (/^#{Regexp.escape(@nick)}!*$/)
          say m.replyto, @lang.get("hello_X") % m.sourcenick
        else
          @keywords.privmsg(m)
      end
    end
  end

  # log a message. Internal use only.
  def log_sent(type, where, message)
    case type
      when "NOTICE"
        if(where =~ /^#/)
          irclog "-=#{@nick}=- #{message}", where
        elsif (where =~ /(\S*)!.*/)
             irclog "[-=#{where}=-] #{message}", $1
        else
             irclog "[-=#{where}=-] #{message}"
        end
      when "PRIVMSG"
        if(where =~ /^#/)
          irclog "<#{@nick}> #{message}", where
        elsif (where =~ /^(\S*)!.*$/)
          irclog "[msg(#{where})] #{message}", $1
        else
          irclog "[msg(#{where})] #{message}", where
        end
    end
  end

  def onjoin(m)
    @channels[m.channel] = IRCChannel.new(m.channel) unless(@channels.has_key?(m.channel))
    if(m.address?)
      debug "joined channel #{m.channel}"
      irclog "@ Joined channel #{m.channel}", m.channel
    else
      irclog "@ #{m.sourcenick} joined channel #{m.channel}", m.channel
      @channels[m.channel].users[m.sourcenick] = Hash.new
      @channels[m.channel].users[m.sourcenick]["mode"] = ""
    end

    @plugins.delegate("listen", m)
    @plugins.delegate("join", m)
  end

  def onpart(m)
    if(m.address?)
      debug "left channel #{m.channel}"
      irclog "@ Left channel #{m.channel} (#{m.message})", m.channel
      @channels.delete(m.channel)
    else
      irclog "@ #{m.sourcenick} left channel #{m.channel} (#{m.message})", m.channel
      if @channels.has_key?(m.channel)
        @channels[m.channel].users.delete(m.sourcenick)
      else
        warning "got part for channel '#{channel}' I didn't think I was in\n"
        # exit 2
      end
    end

    # delegate to plugins
    @plugins.delegate("listen", m)
    @plugins.delegate("part", m)
  end

  # respond to being kicked from a channel
  def onkick(m)
    if(m.address?)
      debug "kicked from channel #{m.channel}"
      @channels.delete(m.channel)
      irclog "@ You have been kicked from #{m.channel} by #{m.sourcenick} (#{m.message})", m.channel
    else
      @channels[m.channel].users.delete(m.sourcenick)
      irclog "@ #{m.target} has been kicked from #{m.channel} by #{m.sourcenick} (#{m.message})", m.channel
    end

    @plugins.delegate("listen", m)
    @plugins.delegate("kick", m)
  end

  def ontopic(m)
    @channels[m.channel] = IRCChannel.new(m.channel) unless(@channels.has_key?(m.channel))
    @channels[m.channel].topic = m.topic if !m.topic.nil?
    @channels[m.channel].topic.timestamp = m.timestamp if !m.timestamp.nil?
    @channels[m.channel].topic.by = m.source if !m.source.nil?

    debug "topic of channel #{m.channel} is now #{@channels[m.channel].topic}"
  end

  # delegate a privmsg to auth, keyword or plugin handlers
  def delegate_privmsg(message)
    [@auth, @plugins, @keywords].each {|m|
      break if m.privmsg(message)
    }
  end
end

end