NEU

[demos/kafka/chat] / src / main / java / de / juplo / kafka / chat / backend / domain / ChatRoom.java

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 63b5b36..b946309 100644 (file)
--- a/src/main/java/de/juplo/kafka/chat/backend/domain/ChatRoom.java
+++ b/src/main/java/de/juplo/kafka/chat/backend/domain/ChatRoom.java
@@ -1,40 +1,44 @@
 package de.juplo.kafka.chat.backend.domain;
 
-import lombok.Getter;
 import lombok.extern.slf4j.Slf4j;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.core.publisher.Sinks;
+import reactor.core.publisher.SynchronousSink;
 
 import java.time.Clock;
 import java.time.LocalDateTime;
 import java.util.*;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 
 @Slf4j
-public class ChatRoom
+public class ChatRoom extends ChatRoomInfo
 {
-  @Getter
-  private final UUID id;
-  @Getter
-  private final String name;
+  public final static Pattern VALID_USER = Pattern.compile("^[a-z0-9-]{2,}$");
   private final Clock clock;
   private final ChatRoomService service;
   private final int bufferSize;
   private Sinks.Many<Message> sink;
 
+
   public ChatRoom(
       UUID id,
       String name,
+      int shard,
       Clock clock,
       ChatRoomService service,
       int bufferSize)
   {
-    this.id = id;
-    this.name = name;
+    super(id, name, shard);
+    log.info("Created ChatRoom {} with buffer-size {}", id, bufferSize);
     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();
   }
 
@@ -44,19 +48,43 @@ 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 ->
+        .getMessage(key)
+        .handle((Message existing, SynchronousSink<Message> sink) ->
         {
-          Sinks.EmitResult result = sink.tryEmitNext(message);
-          if (result.isFailure())
+          if (existing.getMessageText().equals(text))
+          {
+            sink.next(existing);
+          }
+          else
           {
-            log.warn("Emitting of message failed with {} for {}", result.name(), message);
+            sink.error(new MessageMutationException(existing, text));
           }
-        });
+        })
+        .switchIfEmpty(
+            Mono
+                .defer(() -> 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);
+                  }
+                }));
   }
 
 
+  public ChatRoomService getChatRoomService()
+  {
+    return service;
+  }
+
   public Mono<Message> getMessage(String username, Long messageId)
   {
     Message.MessageKey key = Message.MessageKey.of(username, messageId);