1 package de.juplo.kafka.chat.backend.domain;
3 import de.juplo.kafka.chat.backend.domain.exceptions.InvalidUsernameException;
4 import de.juplo.kafka.chat.backend.domain.exceptions.MessageMutationException;
5 import lombok.extern.slf4j.Slf4j;
6 import reactor.core.publisher.Flux;
7 import reactor.core.publisher.Mono;
8 import reactor.core.publisher.Sinks;
9 import reactor.core.publisher.SynchronousSink;
11 import java.time.Clock;
12 import java.time.LocalDateTime;
13 import java.util.regex.Matcher;
14 import java.util.regex.Pattern;
18 public class ChatRoomData
20 public final static Pattern VALID_USER = Pattern.compile("^[a-z0-9-]{2,}$");
22 private final ChatMessageService service;
23 private final Clock clock;
24 private final int historyLimit;
25 private Sinks.Many<Message> sink;
30 ChatMessageService service,
33 log.info("Created ChatRoom with history-limit {}", historyLimit);
35 this.service = service;
36 this.historyLimit = historyLimit;
37 // @RequiredArgsConstructor unfortunately not possible, because
38 // the `historyLimit` is not set, if `createSink()` is called
39 // from the variable declaration!
40 this.sink = createSink();
44 synchronized public Mono<Message> addMessage(
49 Matcher matcher = VALID_USER.matcher(user);
50 if (!matcher.matches())
51 throw new InvalidUsernameException(user);
53 Message.MessageKey key = Message.MessageKey.of(user, id);
56 .handle((Message existing, SynchronousSink<Message> sink) ->
58 if (existing.getMessageText().equals(text))
64 sink.error(new MessageMutationException(existing, text));
69 .defer(() -> service.persistMessage(key, LocalDateTime.now(clock), text))
72 Sinks.EmitResult result = sink.tryEmitNext(m);
73 if (result.isFailure())
75 log.warn("Emitting of message failed with {} for {}", result.name(), m);
81 public ChatMessageService getChatRoomService()
86 public Mono<Message> getMessage(String username, Long messageId)
88 Message.MessageKey key = Message.MessageKey.of(username, messageId);
89 return service.getMessage(key);
92 synchronized public Flux<Message> listen()
96 .doOnCancel(() -> sink = createSink()); // Sink hast to be recreated on auto-cancel!
99 public Flux<Message> getMessages()
101 return getMessages(0, Long.MAX_VALUE);
104 public Flux<Message> getMessages(long first, long last)
106 return service.getMessages(first, last);
111 log.info("{} is being closed", service.getChatRoomId());
112 sink.emitComplete(Sinks.EmitFailureHandler.FAIL_FAST);
115 private Sinks.Many<Message> createSink()
120 .limit(historyLimit);