Moved all business logic into TransferService

[demos/kafka/demos-kafka-payment-system-transfer] / src / main / java / de / juplo / kafka / payment / transfer / domain / TransferService.java

diff --git a/src/main/java/de/juplo/kafka/payment/transfer/domain/TransferService.java b/src/main/java/de/juplo/kafka/payment/transfer/domain/TransferService.java
index 3e6265f..ed1a98e 100644 (file)
--- a/src/main/java/de/juplo/kafka/payment/transfer/domain/TransferService.java
+++ b/src/main/java/de/juplo/kafka/payment/transfer/domain/TransferService.java
@@ -1,70 +1,87 @@
 package de.juplo.kafka.payment.transfer.domain;
 
 
-import de.juplo.kafka.payment.transfer.ports.GetTransferUseCase;
-import de.juplo.kafka.payment.transfer.ports.InitiateTransferUseCase;
-import de.juplo.kafka.payment.transfer.ports.MessagingService;
-import de.juplo.kafka.payment.transfer.ports.TransferRepository;
+import de.juplo.kafka.payment.transfer.ports.*;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 
 import java.util.Optional;
 
-import static de.juplo.kafka.payment.transfer.domain.Transfer.State.*;
+import static de.juplo.kafka.payment.transfer.domain.Transfer.State.CHECKED;
+import static de.juplo.kafka.payment.transfer.domain.Transfer.State.CREATED;
 
 
 @Slf4j
 @RequiredArgsConstructor
-public class TransferService implements InitiateTransferUseCase, GetTransferUseCase
+public class TransferService implements CreateTransferUseCase, HandleStateChangeUseCase, GetTransferUseCase
 {
   private final TransferRepository repository;
   private final MessagingService messagingService;
 
-  public synchronized void initiate(Transfer transfer)
+  @Override
+  public void create(Long id, Long payer, Long payee, Integer amount)
   {
     repository
-        .get(transfer.getId())
+        .get(id)
         .ifPresentOrElse(
-            stored ->
-            {
-              if (!transfer.equals(stored))
-                throw new IllegalArgumentException(
-                    "Re-Initiation of transfer with different data: old=" +
-                        stored +
-                        ", new=" +
-                        transfer);
-
-              if (stored.getState() == FAILED)
-              {
-                repository.update(transfer.getId(), FAILED, SENT);
-                log.info("Resending faild transfer: " + stored);
-                send(transfer);
-              }
-            },
+            stored -> log.info(
+                "transfer already exisits: {}, ignoring: id={}, payer={}, payee={}, amount={}",
+                stored,
+                payer,
+                payee,
+                amount),
             () ->
             {
-              send(transfer);
-              transfer.setState(SENT);
+              Transfer transfer =
+                  Transfer
+                      .builder()
+                      .id(id)
+                      .payer(payer)
+                      .payee(payee)
+                      .amount(amount)
+                      .build();
+
+              log.info("creating transfer: {}", transfer);
               repository.store(transfer);
+              messagingService.send(transfer.getId(), CREATED);
             });
   }
 
-  private void send(Transfer transfer)
+  @Override
+  public void handleStateChange(Long id, Transfer.State state)
   {
-    messagingService
-        .send(transfer)
-        .thenApply(
-            $ ->
-            {
-              repository.update(transfer.getId(), SENT, PENDING);
-              return null;
-            })
-        .exceptionally(
-            e ->
+    get(id)
+        .ifPresentOrElse(
+            transfer ->
             {
-              repository.update(transfer.getId(), SENT, FAILED);
-              return null;
-            });
+              switch (state)
+              {
+                case CREATED:
+
+                  transfer.setState(CREATED);
+                  repository.store(transfer);
+                  check(transfer);
+                  break;
+
+                case CHECKED:
+
+                  transfer.setState(CHECKED);
+                  repository.store(transfer);
+                  // TODO: What's next...?
+                  break;
+
+                default:
+
+                  log.warn("TODO: handle {} state {}", state.foreign ? "foreign" : "domain", state);
+              }
+            },
+            () -> log.error("unknown transfer: {}", id));
+  }
+
+  private void check(Transfer transfer)
+  {
+    // TODO: Do some time consuming checks...
+    messagingService.send(transfer.getId(), CHECKED);
   }
 
   public Optional<Transfer> get(Long id)