class LogicalModel
  module HasManyKeys

    def has_many_keys=(keys)
      @has_many_keys = keys
      attr_accessor *keys

      keys.each do |association|

        # return empty array or @association variable for each association
        define_method association do
          if instance_variable_get("@#{association}").blank?
            instance_variable_set("@#{association}", [])
          end

          instance_variable_get("@#{association}")
        end

        # this method loads the contact attributes recieved by logical model from the service
        define_method "#{association}=" do |params|
          collection = []
          params.each do |attr_params|
            if attr_params["_type"].present?
              attr_class = attr_params.delete("_type").to_s.constantize
            else
              attr_class = association.to_s.singularize.camelize.constantize
            end
            collection << attr_class.new(attr_params)
          end
          instance_variable_set("@#{association}", collection)
        end

        define_method "new_#{association.to_s.singularize}" do |attr_params|
          if attr_params["_type"].present?
            clazz = attr_params.delete(:_type).constantize
          else
            clazz = association.to_s.singularize.camelize.constantize
          end

          return unless clazz

          temp_object = clazz.new(attr_params.merge({"#{self.json_root}_id" => self.id}))
          eval(association.to_s) << temp_object
          temp_object
        end

        # this method loads the contact attributes from the html form (using nested resources conventions)
        define_method "#{association}_attributes=" do |key_attributes|
          array = []
          key_attributes.each do |attr_params|
            attr_params.to_hash.symbolize_keys!
            if attr_params["_type"].present?
              attr_class = attr_params.delete("_type").to_s.constantize
            else
              attr_class = association.to_s.singularize.camelize.constantize
            end
            array << attr_class.new(attr_params)
          end
          instance_variable_set("@#{association}", array)
        end
      end
    end

    def has_many_keys
      @has_many_keys
    end

  end
end