gistfile1.rb

module Intercept
  class << self
    attr_reader :interceptors
    
    def intercept(command, method=nil, &block)
      interceptor = { :command => command, :action => method || block }
      (@interceptors ||= []) << interceptor
    end
  end
  
  protected
    def intercept(command)
      self.class.interceptors.select do |interceptor|
        interceptor[:command] == command
      end.tap do |interceptors|
        if block_given?
          interceptors.each { |interceptor| yield interceptor }
        else
          interceptors
        end
      end
    end
end

class BncsHandler
  include Intercept
  attr_reader :client, :packet, :unpacked
  
  intercept 0x25, :ping
  intercept 0x50, :check_revision
  intercept(0x69) { log "HEY BABY" }
  
  def initialize(client, packet, unpacked)
    @client, @packet, @unpacked = client, packet, unpacked
  end
  
  def command
    @command ||= unpacked[1]
  end
  
  def handle
    log("S->C packet 0x%02X" % command)
    log(packet.hexdump)
    
    intercept(command) do |interceptor|
      action = interceptor[:action]
      case action
      when Symbol then send(action)
      when Proc then action.call(command)
      end
    end
  end
  
  protected
    def log(text)
      puts "[BNCS] #{text}"
    end
    
    def ping
      log "ping!"
    end
    
    def check_revision
      log "check_revision"
    end
end