require File.join( File.dirname( File.expand_path(__FILE__)), 'smell_detector')
require File.join(File.dirname(File.dirname(File.expand_path(__FILE__))), 'smell_warning')
require File.join(File.dirname(File.dirname(File.expand_path(__FILE__))), 'source')

module Reek
  module Smells

    #
    # Feature Envy occurs when a code fragment references another object
    # more often than it references itself, or when several clients do
    # the same series of manipulations on a particular type of object.
    # 
    # A simple example would be the following method, which "belongs"
    # on the Item class and not on the Cart class:
    # 
    #  class Cart
    #    def price
    #      @item.price + @item.tax
    #    end
    #  end
    #
    # Feature Envy reduces the code's ability to communicate intent:
    # code that "belongs" on one class but which is located in another
    # can be hard to find, and may upset the "System of Names"
    # in the host class.
    # 
    # Feature Envy also affects the design's flexibility: A code fragment
    # that is in the wrong class creates couplings that may not be natural
    # within the application's domain, and creates a loss of cohesion
    # in the unwilling host class.
    # 
    # Currently +FeatureEnvy+ reports any method that refers to self less
    # often than it refers to (ie. send messages to) some other object.
    #
    class FeatureEnvy < SmellDetector
      include ExcludeInitialize

      #
      # Checks whether the given +context+ includes any code fragment that
      # might "belong" on another class.
      # Remembers any smells found.
      #
      def examine_context(method_ctx)
        method_ctx.envious_receivers.each do |ref, occurs|
          target = Source::SexpFormatter.format(ref)
          smell = SmellWarning.new('LowCohesion', method_ctx.full_name, [method_ctx.exp.line],
            "refers to #{target} more than self", @masked,
            @source, 'FeatureEnvy', {'receiver' => target, 'references' => occurs})
          @smells_found << smell
          #SMELL: serious duplication
        end
      end
    end
  end
end