X-Git-Url: http://juplo.de/gitweb/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2Fchat%2Fbackend%2Fdomain%2FChatRoom.java;h=1c21fb979a1f2f4c5a061b2c1243d39f24d4cb5c;hb=6eb03cbe4609eea0b7061b574a7e273ecd0c9813;hp=22eebffde1070643b26b12ac6539a1cf3217bee2;hpb=084a922c47f5ecacc7e86c03abd5155fa3255440;p=demos%2Fkafka%2Fchat

diff --git a/src/main/java/de/juplo/kafka/chat/backend/domain/ChatRoom.java b/src/main/java/de/juplo/kafka/chat/backend/domain/ChatRoom.java
index 22eebffd..1c21fb97 100644
--- a/src/main/java/de/juplo/kafka/chat/backend/domain/ChatRoom.java
+++ b/src/main/java/de/juplo/kafka/chat/backend/domain/ChatRoom.java
@@ -11,6 +11,8 @@ import reactor.core.publisher.Sinks;
 import java.time.Clock;
 import java.time.LocalDateTime;
 import java.util.*;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 
 @Slf4j
@@ -18,6 +20,7 @@ import java.util.*;
 @ToString(of = { "id", "name" })
 public class ChatRoom
 {
+  public final static Pattern VALID_USER = Pattern.compile("^[a-z0-9-]{2,}$");
   @Getter
   private final UUID id;
   @Getter
@@ -27,6 +30,7 @@ public class ChatRoom
   private final int bufferSize;
   private Sinks.Many<Message> sink;
 
+
   public ChatRoom(
       UUID id,
       String name,
@@ -39,6 +43,9 @@ public class ChatRoom
     this.clock = clock;
     this.service = service;
     this.bufferSize = bufferSize;
+    // @RequiredArgsConstructor unfortunately not possible, because
+    // the `bufferSize` is not set, if `createSink()` is called
+    // from the variable declaration!
     this.sink = createSink();
   }
 
@@ -48,16 +55,27 @@ public class ChatRoom
       String user,
       String text)
   {
+    Matcher matcher = VALID_USER.matcher(user);
+    if (!matcher.matches())
+      throw new InvalidUsernameException(user);
+
+    Message.MessageKey key = Message.MessageKey.of(user, id);
     return service
-        .persistMessage(Message.MessageKey.of(user, id), LocalDateTime.now(clock), text)
-        .doOnNext(message ->
-        {
-          Sinks.EmitResult result = sink.tryEmitNext(message);
-          if (result.isFailure())
-          {
-            log.warn("Emitting of message failed with {} for {}", result.name(), message);
-          }
-        });
+        .getMessage(key)
+        .flatMap(existing -> text.equals(existing.getMessageText())
+            ? Mono.just(existing)
+            : Mono.error(() -> new MessageMutationException(existing, text)))
+        .switchIfEmpty(
+            Mono
+                .fromSupplier(() ->service.persistMessage(key, LocalDateTime.now(clock), text))
+                .doOnNext(m ->
+                {
+                  Sinks.EmitResult result = sink.tryEmitNext(m);
+                  if (result.isFailure())
+                  {
+                    log.warn("Emitting of message failed with {} for {}", result.name(), m);
+                  }
+                }));
   }