module CurationConcerns
  module Actors
    # Actions are decoupled from controller logic so that they may be called from a controller or a background job.
    class FileSetActor
      include CurationConcerns::Lockable

      attr_reader :file_set, :user, :attributes

      def initialize(file_set, user)
        @file_set = file_set
        @user = user
      end

      # Adds the appropriate metadata, visibility and relationships to file_set
      #
      # *Note*: In past versions of Sufia this method did not perform a save because it is mainly used in conjunction with
      # create_content, which also performs a save.  However, due to the relationship between Hydra::PCDM objects,
      # we have to save both the parent work and the file_set in order to record the "metadata" relationship
      # between them.
      # @param [ActiveFedora::Base] work the parent work that will contain the file_set.
      # @param [Hash] file_set specifying the visibility, lease and/or embargo of the file set.  If you don't provide at least one of visibility, embargo_release_date or lease_expiration_date, visibility will be copied from the parent.

      def create_metadata(work, file_set_params = {})
        file_set.apply_depositor_metadata(user)
        now = CurationConcerns::TimeService.time_in_utc
        file_set.date_uploaded = now
        file_set.date_modified = now
        file_set.creator = [user.user_key]

        Actors::ActorStack.new(file_set, user, [InterpretVisibilityActor]).create(file_set_params) if assign_visibility?(file_set_params)
        attach_file_to_work(work, file_set, file_set_params) if work
        yield(file_set) if block_given?
      end

      # @param [File, ActionDigest::HTTP::UploadedFile, Tempfile] file the file uploaded by the user.
      # @param [String] relation ('original_file')
      def create_content(file, relation = 'original_file')
        # If the file set doesn't have a title or label assigned, set a default.
        file_set.label ||= file.respond_to?(:original_filename) ? file.original_filename : ::File.basename(file)
        file_set.title = [file_set.label] if file_set.title.blank?

        # Need to save the file_set in order to get an id
        return false unless file_set.save

        file_actor_class.new(file_set, relation, user).ingest_file(file)
        true
      end

      # @param [String] revision_id the revision to revert to
      # @param [String] relation ('original_file')
      def revert_content(revision_id, relation = 'original_file')
        file_actor = file_actor_class.new(file_set, relation, user)
        if file_actor.revert_to(revision_id)
          CurationConcerns.config.callback.run(:after_revert_content, file_set, user, revision_id)
          true
        else
          false
        end
      end

      # @param [File, ActionDigest::HTTP::UploadedFile, Tempfile] file the file uploaded by the user.
      # @param [String] relation ('original_file')
      def update_content(file, relation = 'original_file')
        file_actor_class.new(file_set, relation, user).ingest_file(file)
        CurationConcerns.config.callback.run(:after_update_content, file_set, user)
        true
      end

      def update_metadata(attributes)
        stack = Actors::ActorStack.new(file_set,
                                       user,
                                       [InterpretVisibilityActor, BaseActor])
        stack.update(attributes)
      end

      def destroy
        unlink_from_work
        file_set.destroy
        CurationConcerns.config.callback.run(:after_destroy, file_set.id, user)
      end

      def file_actor_class
        CurationConcerns::Actors::FileActor
      end

      private

        # Takes an optional block and executes the block if the save was successful.
        # returns false if the save was unsuccessful
        def save
          save_tries = 0
          begin
            return false unless file_set.save
          rescue RSolr::Error::Http => error
            ActiveFedora::Base.logger.warn "CurationConcerns::Actors::FileSetActor#save Caught RSOLR error #{error.inspect}"
            save_tries += 1
            # fail for good if the tries is greater than 3
            raise error if save_tries >= 3
            sleep 0.01
            retry
          end
          yield if block_given?
          true
        end

        # Adds a FileSet to the work using ore:Aggregations.
        # Locks to ensure that only one process is operating on
        # the list at a time.
        def attach_file_to_work(work, file_set, file_set_params)
          acquire_lock_for(work.id) do
            # Ensure we have an up-to-date copy of the members association, so
            # that we append to the end of the list.
            work.reload unless work.new_record?
            unless assign_visibility?(file_set_params)
              copy_visibility(work, file_set)
            end
            work.ordered_members << file_set
            set_representative(work, file_set)
            set_thumbnail(work, file_set)

            # Save the work so the association between the work and the file_set is persisted (head_id)
            work.save
          end
          CurationConcerns.config.callback.run(:after_create_fileset, file_set, user)
        end

        def assign_visibility?(file_set_params = {})
          !((file_set_params || {}).keys & %w(visibility embargo_release_date lease_expiration_date)).empty?
        end

        # copy visibility from source_concern to destination_concern
        def copy_visibility(source_concern, destination_concern)
          destination_concern.visibility =  source_concern.visibility
        end

        def set_representative(work, file_set)
          return unless work.representative_id.blank?
          work.representative = file_set
        end

        def set_thumbnail(work, file_set)
          return unless work.thumbnail_id.blank?
          work.thumbnail = file_set
        end

        def unlink_from_work
          work = file_set.parent
          return unless work && (work.thumbnail_id == file_set.id || work.representative_id == file_set.id)
          # This is required to clear the thumbnail_id and representative_id
          # fields on the work and force it to be re-solrized. Although
          # ActiveFedora clears the children nodes it leaves the work's
          # thumbnail_id and representative_id fields in Solr populated.
          work.thumbnail = nil if work.thumbnail_id == file_set.id
          work.representative = nil if work.representative_id == file_set.id
          work.save!
        end
    end
  end
end