Allow App To Choose Between MsgResponse Sinks

- MZS Schema Change: Add "MsgResponseSinks" element to
  mzs:DeliveryRequest/Config that allows sender to configure how
  MsgResponses should be archived.
- ConfigUtil: Interpret MsgResponseSink parameters from Spring
  Environment and merge with ConfigType.
- MsgResponseBackend: Send responses to sinks according to
  MsgResponseSinks in Config
- application.yaml: Add MsgResponseSinks parameter to configuration.
- Uncouple Sink implementations from java.util.function.Function,
  because the sink interfaces are going to differ and there is no need
  to unite them under one interface.
- Add and test LogResponseSink, which logs responses to it's logger.
- MsgResponse: Add JAXB getter for response. Reason: Can be passed to
  marshaller.

3 files changed, 88 insertions, 11 deletions

diff --git a/src/main/java/at/gv/egiz/moazs/backend/LogResponseSink.java b/src/main/java/at/gv/egiz/moazs/backend/LogResponseSink.java
new file mode 100644
index 0000000..d419944
--- /dev/null
+++ b/src/main/java/at/gv/egiz/moazs/backend/LogResponseSink.java
@@ -0,0 +1,44 @@
+package at.gv.egiz.moazs.backend;
+
+import at.gv.egiz.moazs.scheme.Marshaller;
+import at.gv.egiz.moazs.scheme.MsgResponse;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import java.util.concurrent.CompletableFuture;
+
+import static java.util.concurrent.CompletableFuture.completedFuture;
+
+@Component
+public class LogResponseSink {
+
+    private static final Logger log = LoggerFactory.getLogger(LogResponseSink.class);
+    private static final String LOG_LEVEL_WARN_MESSAGE = "Will not log response because INFO level is disabled.";
+
+    private final Marshaller msgMarshaller;
+
+    public LogResponseSink(Marshaller msgMarshaller) {
+        this.msgMarshaller = msgMarshaller;
+    }
+
+    /**
+     * Log response to class logger at level=INFO.
+     *
+     * @param msgResponse
+     * @return
+     */
+    public CompletableFuture<Void> log(MsgResponse msgResponse) {
+
+        if(log.isInfoEnabled()) {
+            var builder = new StringBuilder("Received the following Message: \n");
+            builder.append(msgMarshaller.marshallXml(msgResponse.getResponseAsJAXBElement()));
+            log.info(builder.toString());
+        } else {
+            log.warn(LOG_LEVEL_WARN_MESSAGE);
+        }
+
+        return completedFuture(null);
+
+    }
+}
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 414c2dc..1b17f34 100644
--- a/src/main/java/at/gv/egiz/moazs/backend/MsgResponseBackend.java
+++ b/src/main/java/at/gv/egiz/moazs/backend/MsgResponseBackend.java
@@ -4,14 +4,13 @@ import at.gv.egiz.moazs.MoaZSException;
 import at.gv.egiz.moazs.repository.DeliveryRepository;
 import at.gv.egiz.moazs.scheme.MsgResponse;
 import at.gv.egiz.moazs.service.MsgService;
+import at.gv.zustellung.app2mzs.xsd.MsgResponseSinksType;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 
-import java.util.concurrent.CompletableFuture;
 import java.util.function.Consumer;
-import java.util.function.Function;
 
 import static at.gv.egiz.moazs.MoaZSException.moaZSExceptionBuilder;
 import static java.lang.String.format;
@@ -27,29 +26,38 @@ public class MsgResponseBackend implements Consumer<String> {
 
     private final DeliveryRepository repository;
     private final Consumer<byte[]> signatureVerifier;
-    private final Function<MsgResponse, CompletableFuture<Void>> sink;
+    private final SaveResponseToFileSink saveResponseToFileSink;
+    private final LogResponseSink logResponseSink;
 
     @Autowired
     public MsgResponseBackend(DeliveryRepository repository,
                               Consumer<byte[]> signatureVerifier,
-                              Function<MsgResponse, CompletableFuture<Void>> sink) {
+                              SaveResponseToFileSink saveResponseToFileSink,
+                              LogResponseSink logResponseSink) {
         this.repository = repository;
         this.signatureVerifier = signatureVerifier;
-        this.sink = sink;
+        this.saveResponseToFileSink = saveResponseToFileSink;
+        this.logResponseSink = logResponseSink;
     }
 
     /**
      * Performs all {@code MsgResponse}'s Back-End Tasks, such as verifying
      * its signature and archiving the response.
      *
+     * Note: When the signature verification fails, this method will not archive
+     * the original response (the one that was received from msg) to the sink,
+     * but an error message.
+     *
      * @param responseID refers to MsgResponse Object.
      */
     @Override
     public void accept(String responseID) {
-        supplyAsync(() -> verify(responseID)).thenAcceptAsync(sink::apply);
+
+        supplyAsync(() -> verify(responseID))
+                .thenAcceptAsync(msgResponse -> applySinks(msgResponse));
     }
 
-    public MsgResponse verify(String responseID) {
+    private MsgResponse verify(String responseID) {
 
         var response = repository.retrieveResponse(responseID).get();
         var builder = moaZSExceptionBuilder().withAllParametersInAnswer(response.getAnswer());
@@ -72,4 +80,23 @@ public class MsgResponseBackend implements Consumer<String> {
 
     }
 
+    private void applySinks(MsgResponse msgResponse) {
+
+        var sinkParams = getSinkParams(msgResponse);
+
+        if (sinkParams.isSafeResponseToFile()) {
+            supplyAsync(() -> saveResponseToFileSink.save(msgResponse));
+        }
+
+        if (sinkParams.isLogResponse()) {
+            supplyAsync(() -> logResponseSink.log(msgResponse));
+        }
+    }
+
+    private MsgResponseSinksType getSinkParams(MsgResponse msgResponse) {
+        var appDeliveryID = msgResponse.getAppDeliveryID();
+        var request = repository.retrieveDeliveryRequest(appDeliveryID).get();
+        return request.getConfig().getMsgResponseSinks();
+    }
+
 }
diff --git a/src/main/java/at/gv/egiz/moazs/backend/SaveResponseToFileSink.java b/src/main/java/at/gv/egiz/moazs/backend/SaveResponseToFileSink.java
index 02771a9..7da76ef 100644
--- a/src/main/java/at/gv/egiz/moazs/backend/SaveResponseToFileSink.java
+++ b/src/main/java/at/gv/egiz/moazs/backend/SaveResponseToFileSink.java
@@ -15,7 +15,6 @@ import java.nio.charset.StandardCharsets;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.concurrent.CompletableFuture;
-import java.util.function.Function;
 
 import static at.gv.egiz.moazs.MoaZSException.moaZSException;
 import static java.lang.String.format;
@@ -23,10 +22,11 @@ import static java.util.concurrent.CompletableFuture.allOf;
 import static java.util.concurrent.CompletableFuture.supplyAsync;
 
 @Component
-public class SaveResponseToFileSink implements Function<MsgResponse, CompletableFuture<Void>> {
+public class SaveResponseToFileSink {
 
     private static final Logger log = LoggerFactory.getLogger(SaveResponseToFileSink.class);
     private static final String SAVING_FAILED_MSG = "Could not save response with AppDeliveryId=%s.";
+    private static final String SAVE_RESPONSE_MSG = "Saving response to {}..." ;
 
     private final SimpleDateFormat isoFormatter;
     private final Marshaller msgMarshaller;
@@ -41,8 +41,13 @@ public class SaveResponseToFileSink implements Function<MsgResponse, Completable
         this.isoFormatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
     }
 
-    @Override
-    public CompletableFuture<Void> apply(MsgResponse response) {
+    /**
+     * Save response and it's binary version to the file system.
+     *
+     * @param response
+     * @return Future that completes when both responses have been written to the file system.
+     */
+    public CompletableFuture<Void> save(MsgResponse response) {
 
         var responseID = response.getResponseID();
 
@@ -79,6 +84,7 @@ public class SaveResponseToFileSink implements Function<MsgResponse, Completable
     }
 
     private void storeToFile(String path, byte[] content) {
+        log.trace(SAVE_RESPONSE_MSG, path);
         try {
             FileUtils.writeByteArrayToFile(new File(path), content);
         } catch (IOException e) {