module Fiona7
  class ReleaseController < ActionController::Base
    def release
      @releasable = Set.new
      @errors = []

      @obj = WriteObj.find(params[:id])

      recursively_find_objects(@releasable, @obj, Set.new)

      @releasable.each do |obj|
        if obj.really_edited?
          carefully_release(@errors, obj)
        end
      end

      # TODO: display errors
      render json: {}
    end

    protected

    def carefully_release(errors, obj)
      obj.take
      obj.release!
    rescue => e
      Rails.logger.error("Error occured when releasing #{@obj.id}: unable to release Object with ID #{obj.id} (#{obj.path} because: #{e.inspect}")

      # TODO: translate
      error = "Unable to release Object with ID #{obj.id} because: #{e.message}"
      errors << error
    end

    def recursively_find_objects(set, obj, already_encountered)
      # already_encountered prevents loops
      widgets_of_this_object = widgets(obj) - already_encountered
      referenced_objects_of_this_object = referenced_objects(obj) - already_encountered

      already_encountered.merge(widgets_of_this_object)
      already_encountered.merge(referenced_objects_from_widgets)

      widgets_of_this_object.each do |widget|
        recursively_find_objects(set, widget, already_encountered)
      end

      referenced_objects_of_this_object.each do |referenced|
        recursively_find_objects(set, referenced, already_encountered)
      end

      set.merge(widgets_of_this_object)
      set.merge(referenced_objects_of_this_object)
      set << obj

      set
    end

    def widgets(obj)
      links = @obj[:X_widget_pool] || []
      WriteObj.where(obj_id: links.map {|l| l.destination_object_id }).to_a.to_set
    end

    def referenced_objects(obj)
      referenced = Set.new

      type_definition = Fiona7::TypeRegister.instance.read_mangled(obj.obj_class)
      type_definition.attributes.each do |attribute|
        if attribute.type == :reference || attribute.type == :referencelist
          (obj[attribute.real_name] || []).each do |link|
            if link.internal?
              referenced << link.destination_object
            end
          end
        end
      end

      referenced
    end
  end
end