Put MoaZSException on Diet & Handle Edge Cases

Reason: MoaZSException (and: its builder) were used to collect
intermediary results while stepping through the delivery request
backend. These results were needed to generate meaningful responses
towards the sender application in case of error. However, the builder
sprawled over too many interfaces (e.g. DeliveryRequestBackend and
TNVZHelper) and it became difficult to understand from where
intermediary results originated.

Solution: Put MoaZSException on diet:
- Remove all DeliveryAnswer fields from MoaZSException and refactor
  code base to ensure that the removed fields get sourced by other
  means.
- Remove Builder since amount of parameters is manageable.

Refactor DeliveryRequestBackend:
- Instead of passing down the builder and using MoaZSException as the
  only source for intermediary results, we collect available results
  at the outermost stack frame (DeliveryRequestBackend.accept) and
  only retrieve results via exception if those results appear
  somewhere down the stack frame (E.g. PredviceNoteSent). We collect
  available results with the "fallbackAnswerBuilder" and switch to the
  msg client response, once received.

Refactor MsgResponseBackend:
- Handle cases (response missing, binary response missing) properly.
- Integrate changes from MsgResponse.generateError()

Refactor TVNZHelper:
- Remove MoaZSExceptionBuilder from all interfaces.

Refactor MsgResponse.generateError:
- Change interface such that it's more intuitive.
- Implement NotificationResponse.generateError.
- Implement RequestStatusResponse.generateError.

Others:
- Replace all invocations against MoaZSException.Builder.

1 files changed, 15 insertions, 13 deletions

diff --git a/src/main/java/at/gv/egiz/moazs/backend/MsgResponseBackend.java b/src/main/java/at/gv/egiz/moazs/backend/MsgResponseBackend.java
index 9e3cd36..8649a32 100644
--- a/src/main/java/at/gv/egiz/moazs/backend/MsgResponseBackend.java
+++ b/src/main/java/at/gv/egiz/moazs/backend/MsgResponseBackend.java
@@ -12,7 +12,7 @@ import org.springframework.stereotype.Component;
 
 import java.util.function.Consumer;
 
-import static at.gv.egiz.moazs.MoaZSException.moaZSExceptionBuilder;
+import static at.gv.egiz.moazs.MoaZSException.*;
 import static java.lang.String.format;
 import static java.util.concurrent.CompletableFuture.supplyAsync;
 
@@ -23,6 +23,8 @@ public class MsgResponseBackend implements Consumer<String> {
 
     public static final String MOASP_SIGNATURE_INVALID_ERROR_MSG = "Signature of Msg Response " +
             "with AppDeliveryID=%s is not valid.";
+    public static final String BINARY_RESPONSE_MISSING_ERROR_MSG = "Binary Response is not in repository.";
+    public static final String RESPONSE_MISSING_ERROR_MSG = "Response with ResponseID=%s is not in repository.";
 
     private final DeliveryRepository repository;
     private final Consumer<byte[]> signatureVerifier;
@@ -58,28 +60,28 @@ public class MsgResponseBackend implements Consumer<String> {
     public void accept(String responseID) {
 
         supplyAsync(() -> verify(responseID))
-                .thenAcceptAsync(msgResponse -> applySinks(msgResponse));
+                .thenAcceptAsync(msgResponse -> applySinks(msgResponse))
+                .exceptionally(ex -> {
+                    log.error(ex.getMessage(), ex);
+                    return null;
+                });
     }
 
     private MsgResponse verify(String responseID) {
 
-        var response = repository.retrieveResponse(responseID).get();
-        var builder = moaZSExceptionBuilder().withAllParametersInAnswer(response.getAnswer());
-
-        var binaryResponse = repository.retrieveBinaryResponse(responseID).get();
+        var response = repository.retrieveResponse(responseID).orElseThrow(
+                ()-> moaZSException(format(RESPONSE_MISSING_ERROR_MSG, responseID)));
 
         try {
+            var binaryResponse = repository.retrieveBinaryResponse(responseID).orElseThrow(
+                    () -> moaZSException(BINARY_RESPONSE_MISSING_ERROR_MSG, MoaZSException.ERROR_MZS_BINARY_RESPONSE_MISSING));
             signatureVerifier.accept(binaryResponse);
             return response;
         } catch (MoaZSException ex) {
             log.error(ex.getMessage(), ex);
-            var wrappingEx = builder
-                    .withMessage(format(MOASP_SIGNATURE_INVALID_ERROR_MSG, response.getAppDeliveryID()))
-                    .withErrorCode(MoaZSException.ERROR_MOASP_SIGNATURE_INVALID)
-                    .withCause(ex)
-                    .build();
-
-            return response.generateError(wrappingEx);
+            var text = format(MOASP_SIGNATURE_INVALID_ERROR_MSG, response.getAppDeliveryID());
+            var code = ERROR_MOASP_SIGNATURE_INVALID;
+            return response.generateError(text, code);
         }
 
     }