# Copyright: Copyright 2009 Topic Maps Lab, University of Leipzig.
# License:   Apache License, Version 2.0

module RTM
  module Navigation
    module Topic
      
      # Returns all Topic players that exist in binary supertype-subtype Associations
      # where this Topic playes the subtype-Role.
      #
      # The result may be an empty Array.
      #
      # :call-seq:
      #   direct-supertypes -> Array of Topics
      #
      def direct_supertypes
        roles_played(topic_map.get(RTM::PSI[:subtype]),topic_map.get(RTM::PSI[:supertype_subtype])).
          reject{|r| r.getParent.getRoles.size!=2}.
          map{|r| r.parent[RTM::PSI[:supertype]].first.player}.flatten.uniq
      end
      
      # Creates a binary supertype-subtype-Association where identifier defines
      # the player of the supertype-Role. The current Topic will play the
      # subtype-Role. Returns the created Association.
      #
      # Identifier may be a topic reference.
      #
      # :call-seq:
      #   add_supertype(identifier) -> Association
      #
      def add_supertype(new_supertype)
        asso = topic_map.create_association(RTM::PSI[:supertype_subtype])
        asso.create_role(RTM::PSI[:subtype],self)
        asso.create_role(RTM::PSI[:supertype],new_supertype)
        asso
      end

      # Creates one or several binary supertype-subtype-Associations where
      # each identifier defines
      # the player of a supertype-Role. The current topic will play the
      # subtype-Role in each association. Returns the associations.
      #
      # The identifiers may be topic references.
      #
      # :call-seq:
      #   add_supertypes(identifier1, identifier2, ...) -> Array of Associtions
      #
      def add_supertypes(*args)
        args.flatten!
        args.map{|identifier| add_supertype(identifier)}
      end

      # Returns all supertypes of this Topic. The result includes 
      # all direct supertypes
      # and the supertypes of these direct supertypes.
      #
      # The result may be an empty Array.
      #
      # :call-seq:
      #   transitive_supertypes -> Array of Topics
      #
      def transitive_supertypes
#       topic_map.cached self, :transitive_supertypes do
          result_types = new_s_t = direct_supertypes
          until new_s_t.empty?
            new_s_t = new_s_t.map{|s| s.direct_supertypes}.flatten.uniq
            new_s_t = new_s_t.reject{|s| result_types.include?(s)}
            result_types = result_types + new_s_t
          end
          result_types
#       end
      end
      
      # Returns all supertypes of this Topic. The result includes the direct_supertypes
      # and the supertypes of these direct_supertypes of this Topic as well as the Topic itself.
      #
      # :call-seq:
      #   transitive_supertypes_with_self -> Array of Topics
      #
      def transitive_supertypes_with_self
        transitive_supertypes + [self]
      end
      
      # Returns all Topics that exist in binary supertype-subtype Associations
      # where this Topic playes the supertype-Role.
      #
      # The result may be an empty Array.
      #
      # :call-seq:
      #   direct-subtypes -> Array of Topics
      #
      def direct_subtypes
        roles(topic_map.get(RTM::PSI[:supertype]),topic_map.get(RTM::PSI[:supertype_subtype])).
          reject{|r| r.getParent.getRoles.size!=2}.
          map {|r| r.getParent[RTM::PSI[:subtype]].first.player}.flatten.uniq
      end
      
      # Creates a binary supertype-subtype-Association where identifier defines
      # the player of the subtype-Role. The current Topic will play the
      # supertype-Role. Returns the created Association.
      #
      # Identifier may be topic reference.
      #
      # :call-seq:
      #   add_subtype(identifier) -> Association
      #
      def add_subtype(new_subtype)
        asso = topic_map.create_association(RTM::PSI[:supertype_subtype])
        asso.create_role(RTM::PSI[:supertype],self)
        asso.create_role(RTM::PSI[:subtype],new_subtype)
        asso
      end

      # Creates one or several binary supertype-subtype-Associations where
      # each identifier defines
      # the player of a subtype-Role. The current topic will play the
      # supertype-Role in each association. Returns the associations.
      #
      # The identifiers may be topic references.
      #
      # :call-seq:
      #   add_subtypes(identifier1, identifier2, ...) -> Array of Associtions
      #
      def add_subtypes(*args)
        args.flatten!
        args.map{|identifier| add_subtype(identifier)}
      end

      # Returns all subtypes of this Topic. The result includes the direct subtypes
      # and the subtypes of these direct subtypes.
      #
      # The result may be an empty Array.
      #
      # :call-seq:
      #   transitive_subtypes -> Array of Topics
      #
      def transitive_subtypes
        topic_map.cached self, :transitive_subtypes do
          result_types = new_s_t = direct_subtypes
          until new_s_t.empty?
            new_s_t = new_s_t.map{|s| s.direct_subtypes}.flatten.uniq
            new_s_t = new_s_t.reject{|s| result_types.include?(s)}
            result_types = result_types + new_s_t
          end
          result_types
        end
      end
      
      # Returns all subtypes of this Topic. The result includes the direct_subtypes
      # and the subtypes of these direct_subtypes of this Topic as well as the Topic itself.
      #
      # :call-seq:
      #   transitive_subtypes_with_self -> Array of Topics
      #
      def transitive_subtypes_with_self
        transitive_subtypes + [self]
      end
      
      alias :supertypes :transitive_supertypes
      alias :subtypes :transitive_subtypes
      alias :reverse_subtypes :supertypes
      alias :reverse_supertypes :subtypes
      
    end
  end
end