module Kernel

  # which { some_object.some_method() } => <file>:<line>:
  def where_is_this_defined(settings={}, &block)
    settings[:debug] ||= false
    settings[:educated_guess] ||= false
    
    events = []
    
    set_trace_func lambda { |event, file, line, id, binding, classname|
      events << { :event => event, :file => file, :line => line, :id => id, :binding => binding, :classname => classname }
      
      if settings[:debug]
        puts "event => #{event}"
        puts "file => #{file}"
        puts "line => #{line}"
        puts "id => #{id}"
        puts "binding => #{binding}"
        puts "classname => #{classname}"
        puts ''
      end
    }
    yield
    set_trace_func(nil)

    events.each do |event|
      next unless event[:event] == 'call' or (event[:event] == 'return' and event[:classname].included_modules.include?(ActiveRecord::Associations))
      return "#{event[:classname]} received message '#{event[:id]}', Line \##{event[:line]} of #{event[:file]}"
    end
    
    # def self.crazy_custom_finder
    #  return find(:all......)
    # end
    # return unless event == 'call' or (event == 'return' and classname.included_modules.include?(ActiveRecord::Associations))
    # which_file = "Line \##{line} of #{file}"
    if settings[:educated_guess] and events.size > 3
      event = events[-3]
      return "#{event[:classname]} received message '#{event[:id]}', Line \##{event[:line]} of #{event[:file]}"
    end
    
    return 'Unable to determine where method was defined.'
  end

end

>> where_is_this_defined {Streamlined.ui_for(:foo)}
=> "Streamlined received message 'ui_for', Line #6 of /Users/abedra/src/someapp/trunk/lib/extensions/streamlined/streamlined.rb"