refactor: Refined return-type of `StorageStrategy#write`

[demos/kafka/chat] / src / main / java / de / juplo / kafka / chat / backend / implementation / StorageStrategy.java

diff --git a/src/main/java/de/juplo/kafka/chat/backend/implementation/StorageStrategy.java b/src/main/java/de/juplo/kafka/chat/backend/implementation/StorageStrategy.java
index 2913efe..94b2bb4 100644 (file)
--- a/src/main/java/de/juplo/kafka/chat/backend/implementation/StorageStrategy.java
+++ b/src/main/java/de/juplo/kafka/chat/backend/implementation/StorageStrategy.java
@@ -1,29 +1,42 @@
-package de.juplo.kafka.chat.backend.persistence;
+package de.juplo.kafka.chat.backend.implementation;
 
 import de.juplo.kafka.chat.backend.domain.ChatHomeService;
 import de.juplo.kafka.chat.backend.domain.ChatRoomInfo;
 import de.juplo.kafka.chat.backend.domain.Message;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
 
 import java.util.UUID;
 
 
 public interface StorageStrategy
 {
-  default void write(ChatHomeService chatHomeService)
+  Logger log = LoggerFactory.getLogger(StorageStrategy.class.getCanonicalName());
+
+  default Mono<Void> write(ChatHomeService chatHomeService)
   {
-    writeChatRoomInfo(
+    return writeChatRoomInfo(
         chatHomeService
             .getChatRoomInfo()
-            .doOnNext(chatRoomInfo -> writeChatRoomData(
+            .flatMap(chatRoomInfo -> writeChatRoomData(
                 chatRoomInfo.getId(),
                 chatHomeService
                     .getChatRoomData(chatRoomInfo.getId())
-                    .flatMapMany(chatRoomData -> chatRoomData.getMessages()))));
+                    .flatMapMany(chatRoomData -> chatRoomData.getMessages())
+                )
+                .then(Mono.just(chatRoomInfo))
+                .doOnSuccess(emittedChatRoomInfo -> log.info("Stored {}", chatRoomInfo))
+                .doOnError(throwable -> log.error("Could not store {}: {}", chatRoomInfo, throwable)))
+        )
+        .then()
+        .doOnSuccess(empty -> log.info("Stored {}", chatHomeService))
+        .doOnError(throwable -> log.error("Could not store {}: {}", chatHomeService, throwable));
   }
 
-  void writeChatRoomInfo(Flux<ChatRoomInfo> chatRoomInfoFlux);
+  Flux<ChatRoomInfo> writeChatRoomInfo(Flux<ChatRoomInfo> chatRoomInfoFlux);
   Flux<ChatRoomInfo> readChatRoomInfo();
-  void writeChatRoomData(UUID chatRoomId, Flux<Message> messageFlux);
+  Flux<Message> writeChatRoomData(UUID chatRoomId, Flux<Message> messageFlux);
   Flux<Message> readChatRoomData(UUID chatRoomId);
 }