juplo.de Git - demos/kafka/demos-kafka-payment-system-transfer/blob - src/main/java/de/juplo/kafka/payment/transfer/ports/TransferService.java

   1 package de.juplo.kafka.payment.transfer.ports;
   2
   3
   4 import de.juplo.kafka.payment.transfer.adapter.TransferStateChangedEvent;
   5 import de.juplo.kafka.payment.transfer.domain.Transfer;
   6 import lombok.RequiredArgsConstructor;
   7 import lombok.extern.slf4j.Slf4j;
   8
   9 import java.util.Optional;
  10
  11 import static de.juplo.kafka.payment.transfer.domain.Transfer.State.CHECKED;
  12 import static de.juplo.kafka.payment.transfer.domain.Transfer.State.CREATED;
  13
  14
  15 @Slf4j
  16 @RequiredArgsConstructor
  17 public class TransferService implements CreateTransferUseCase, HandleStateChangeUseCase, GetTransferUseCase
  18 {
  19   private final TransferRepository repository;
  20   private final MessagingService messagingService;
  21
  22   @Override
  23   public Optional<TransferStateChangedEvent> create(Long id, Long payer, Long payee, Integer amount)
  24   {
  25     return
  26     repository
  27         .get(id)
  28         .flatMap(
  29             stored ->
  30             {log.info(
  31                 "transfer already exisits: {}, ignoring: id={}, payer={}, payee={}, amount={}",
  32                 stored,
  33                 payer,
  34                 payee,
  35                 amount);
  36             return Optional.empty();
  37             })
  38         .or(() ->
  39             {
  40               log.info("creating transfer: {}", transfer);
  41               return
  42                   TransferStateChangedEvent
  43                       .builder()
  44                       .id(transfer.getId())
  45                       .state(CREATED)
  46                       .build();
  47             });
  48   }
  49
  50   @Override
  51   public TransferStateChangedEvent handleStateChange(Long id, Transfer.State state)
  52   {
  53     get(id)
  54         .ifPresentOrElse(
  55             transfer ->
  56             {
  57               switch (state)
  58               {
  59                 case CREATED:
  60
  61                   transfer.setState(CREATED);
  62                   repository.store(transfer);
  63                   check(transfer);
  64                   break;
  65
  66                 case CHECKED:
  67
  68                   transfer.setState(CHECKED);
  69                   repository.store(transfer);
  70                   // TODO: What's next...?
  71                   break;
  72
  73                 default:
  74
  75                   log.warn("TODO: handle {} state {}", state.foreign ? "foreign" : "domain", state);
  76               }
  77             },
  78             () -> log.error("unknown transfer: {}", id));
  79   }
  80
  81   private void check(Transfer transfer)
  82   {
  83     // TODO: Do some time consuming checks...
  84     messagingService.send(transfer.getId(), CHECKED);
  85   }
  86
  87   public Optional<Transfer> get(Long id)
  88   {
  89     return repository.get(id);
  90   }
  91 }