# frozen_string_literal: true

module ConvenientService
  module Service
    module Plugins
      module RaisesOnDoubleResult
        class Middleware < Core::MethodChainMiddleware
          def next(...)
            refute_has_result! || mark_as_has_result!

            chain.next(...)
          end

          private

          ##
          # NOTE: `refute` is `!assert`.
          # https://docs.seattlerb.org/minitest
          #
          def refute_has_result!
            return unless entity.internals.cache.exist?(:has_result)

            raise Errors::DoubleResult.new(service: entity)
          end

          def mark_as_has_result!
            entity.internals.cache.write(:has_result, true)
          end
        end
      end
    end
  end
end