refactor: Simplified `StorageStrategy`
[demos/kafka/chat] / src / main / java / de / juplo / kafka / chat / backend / implementation / StorageStrategy.java
1 package de.juplo.kafka.chat.backend.implementation;
2
3 import de.juplo.kafka.chat.backend.domain.ChatHomeService;
4 import de.juplo.kafka.chat.backend.domain.ChatRoomInfo;
5 import de.juplo.kafka.chat.backend.domain.Message;
6 import org.slf4j.Logger;
7 import org.slf4j.LoggerFactory;
8 import reactor.core.publisher.Flux;
9
10 import java.util.UUID;
11
12
13 public interface StorageStrategy
14 {
15   Logger log = LoggerFactory.getLogger(StorageStrategy.class.getCanonicalName());
16
17   default Flux<ChatRoomInfo> write(ChatHomeService chatHomeService)
18   {
19     return writeChatRoomInfo(
20         chatHomeService
21             .getChatRoomInfo()
22             .doOnComplete(() -> log.info("Stored {}", chatHomeService))
23             .doOnError(throwable -> log.error("Could not store {}: {}", chatHomeService, throwable))
24             .doOnNext(chatRoomInfo ->
25                 writeChatRoomData(
26                     chatRoomInfo.getId(),
27                     chatHomeService
28                         .getChatRoomData(chatRoomInfo.getId())
29                         .flatMapMany(chatRoomData -> chatRoomData.getMessages())
30                         .doOnComplete(() -> log.info("Stored {}", chatRoomInfo))
31                         .doOnError(throwable -> log.error("Could not store {}: {}", chatRoomInfo, throwable)))
32                     .subscribe()));
33   }
34
35   Flux<ChatRoomInfo> writeChatRoomInfo(Flux<ChatRoomInfo> chatRoomInfoFlux);
36   Flux<ChatRoomInfo> readChatRoomInfo();
37   Flux<Message> writeChatRoomData(UUID chatRoomId, Flux<Message> messageFlux);
38   Flux<Message> readChatRoomData(UUID chatRoomId);
39 }