module Ddr::Batch

  class UpdateBatchObject < BatchObject

    def local_validations
      errs = []
      errs << "#{@error_prefix} PID required for UPDATE operation" unless pid
      if pid
        if ActiveFedora::Base.exists?(pid)
          errs << "#{@error_prefix} #{batch.user.user_key} not permitted to edit #{pid}" unless batch.user.can?(:edit, ActiveFedora::Base.find(pid, :cast => true))
        else
          errs << "#{@error_prefix} PID #{pid} not found in repository" unless ActiveFedora::Base.exists?(pid)
        end
      end
      errs
    end

    def model_datastream_keys
      if pid
        begin
          obj = ActiveFedora::Base.find(pid, :cast => true)
          obj.datastreams.keys
        rescue
          nil
        end
      end
    end

    def process(user, opts = {})
      unless verified
        repo_object = update_repository_object(user, opts)
        verifications = verify_repository_object
        verification_outcome_detail = []
        verified = true
        verifications.each do |key, value|
          verification_outcome_detail << "#{key}...#{value}"
          verified = false if value.eql?(VERIFICATION_FAIL)
        end
        update_attributes(:verified => verified)
        Ddr::Events::ValidationEvent.new.tap do |event|
          event.object = repo_object
          event.failure! unless verified
          event.summary = EVENT_SUMMARY % {
              label: "Object update validation",
              batch_id: id,
              identifier: identifier,
              model: model
          }
          event.detail = verification_outcome_detail.join("\n")
          event.save!
        end
        repo_object
      end
    end

    def results_message
      if pid
        message_level = verified ? Logger::INFO : Logger::WARN
        verification_result = verified ? "Verified" : "VERIFICATION FAILURE"
        ProcessingResultsMessage.new(message_level, "Updated #{pid}...#{verification_result}")
      else
        ProcessingResultsMessage.new(Logger::ERROR, "Attempt to update #{model} #{identifier} FAILED")
      end
    end

    def event_log_comment
      "Updated by batch process (Batch #{batch.id}, BatchObject #{id})"
    end

    private

    def update_repository_object(user, opts = {})
      repo_object = nil
      begin
        repo_object = ActiveFedora::Base.find(pid)
        update!(model: repo_object.class.name) unless model.present?
        batch_object_attributes.each do |a|
          repo_object = case
          when a.operation.eql?(BatchObjectAttribute::OPERATION_ADD)
            add_attribute(repo_object, a)
          when a.operation.eql?(BatchObjectAttribute::OPERATION_CLEAR)
            clear_attribute(repo_object, a)
          when a.operation.eql?(BatchObjectAttribute::OPERATION_CLEAR_ALL)
            clear_attributes(repo_object, a)
          end
        end
        batch_object_datastreams.each do |d|
          repo_object = case
          when d.operation.eql?(BatchObjectDatastream::OPERATION_ADDUPDATE)
            populate_datastream(repo_object, d)
          end
        end
        repo_object.save!(user: user, comment: event_log_comment)
      rescue Exception => e
        logger.error("Error in updating repository object #{pid} for #{identifier} : : #{e}")
        raise e
      end
      repo_object
    end

  end
end