Changed internal representation of messages and added LLM required ordering of messages.

src/main/java/com/meta/cp4m/message/FBMessage.java

@@ -9,6 +9,8 @@
 package com.meta.cp4m.message;
 
 import com.meta.cp4m.Identifier;
+import org.checkerframework.checker.lock.qual.NewObject;
+
 import java.time.Instant;
 
 public record FBMessage(
@@ -17,5 +19,11 @@ public record FBMessage(
     Identifier senderId,
     Identifier recipientId,
     String message,
-    Role role)
-    implements Message {}
+    Role role,
+    Message parentMessage)
+    implements Message {
+    @Override
+    public @NewObject Message withParentMessage(Message parentMessage) {
+        return new FBMessage(timestamp(),instanceId(),senderId(),recipientId(),message(), role(), parentMessage);
+    }
+}

src/main/java/com/meta/cp4m/message/FBMessageHandler.java

@@ -40,6 +40,8 @@ public class FBMessageHandler implements MessageHandler<FBMessage> {
   private static final Logger LOGGER = LoggerFactory.getLogger(FBMessageHandler.class);
   private static final TextChunker CHUNKER = TextChunker.standard(2000);
 
+  private static final MessageFactory<FBMessage> MESSAGE_FACTORY = MessageFactory.instance(FBMessage.class);
+
   private final String verifyToken;
   private final String appSecret;
 
@@ -125,14 +127,7 @@ private List<FBMessage> postHandler(Context ctx, JsonNode body) {
 
           @Nullable JsonNode textObject = messageObject.get("text");
           if (textObject != null && textObject.isTextual()) {
-            FBMessage m =
-                new FBMessage(
-                    timestamp,
-                    messageId,
-                    senderId,
-                    recipientId,
-                    textObject.textValue(),
-                    Message.Role.USER);
+            FBMessage m = MESSAGE_FACTORY.newMessage(timestamp, textObject.textValue(), senderId, recipientId,messageId, Message.Role.USER);
             output.add(m);
           } else {
             LOGGER

src/main/java/com/meta/cp4m/message/Message.java

@@ -9,17 +9,21 @@
 package com.meta.cp4m.message;
 
 import com.meta.cp4m.Identifier;
+import org.checkerframework.checker.lock.qual.NewObject;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
 import java.time.Instant;
 
 public interface Message {
-
-  static Identifier threadId(Identifier id1, Identifier id2) {
+  private static Identifier threadId(Identifier id1, Identifier id2) {
     if (id1.compareTo(id2) <= 0) {
       return Identifier.from(id1.toString() + '|' + id2);
     }
     return Identifier.from(id2.toString() + '|' + id1);
   }
 
+  public <T extends Message> @NewObject T withParentMessage(Message parentMessage);
+
   Instant timestamp();
 
   Identifier instanceId();
@@ -32,13 +36,26 @@ static Identifier threadId(Identifier id1, Identifier id2) {
 
   Role role();
 
+  @Nullable Message parentMessage();
+
   default Identifier threadId() {
     return threadId(senderId(), recipientId());
   }
 
   enum Role {
-    ASSISTANT,
-    USER,
-    SYSTEM
+    ASSISTANT(0),
+    USER(1),
+    SYSTEM(2);
+
+    private final int priority;
+
+    private Role(Integer priority){
+      this.priority = priority;
+    }
+
+    public int getPriority(){
+      return this.priority;
+    }
+
   }
 }

src/main/java/com/meta/cp4m/message/MessageFactory.java

@@ -21,9 +21,9 @@ public interface MessageFactory<T extends Message> {
   Map<Class<? extends Message>, MessageFactory<? extends Message>> FACTORY_MAP =
       Stream.<FactoryContainer<?>>of(
               new FactoryContainer<>(
-                  FBMessage.class, (t, m, si, ri, ii, r) -> new FBMessage(t, ii, si, ri, m, r)),
+                  FBMessage.class, (t, m, si, ri, ii, r) -> new FBMessage(t, ii, si, ri, m, r,null)),
               new FactoryContainer<>(
-                  WAMessage.class, (t, m, si, ri, ii, r) -> new WAMessage(t, ii, si, ri, m, r)))
+                  WAMessage.class, (t, m, si, ri, ii, r) -> new WAMessage(t, ii, si, ri, m, r,null)))
           .collect(
               Collectors.toUnmodifiableMap(FactoryContainer::clazz, FactoryContainer::factory));
 

src/main/java/com/meta/cp4m/message/ThreadState.java

@@ -33,26 +33,30 @@ private ThreadState(T message) {
   private ThreadState(ThreadState<T> old, T newMessage) {
     Objects.requireNonNull(newMessage);
     Preconditions.checkArgument(
-        newMessage.role() != Role.SYSTEM, "ThreadState should never hold a system message");
+            newMessage.role() != Role.SYSTEM, "ThreadState should never hold a system message");
     messageFactory = old.messageFactory;
     Preconditions.checkArgument(
         old.tail().threadId().equals(newMessage.threadId()),
         "all messages in a thread must have the same thread id");
     List<T> messages = old.messages;
-    if (newMessage.timestamp().isBefore(old.tail().timestamp())) {
-      this.messages =
-          Stream.concat(messages.stream(), Stream.of(newMessage))
-              .sorted(Comparator.comparing(Message::timestamp))
+    T mWithParentMessage = newMessage.role() == Role.USER ? newMessage.withParentMessage(old.tail()): newMessage;
+    this.messages =
+          Stream.concat(messages.stream(), Stream.of(mWithParentMessage))
+              .sorted((m1,m2) -> m1.parentMessage() == m2.parentMessage() ? compare(m1.role().getPriority(),m2.role().getPriority()) : (m1.timestamp().compareTo(m2.timestamp())))
               .collect(Collectors.toUnmodifiableList());
-    } else {
-      this.messages = ImmutableList.<T>builder().addAll(messages).add(newMessage).build();
-    }
-
+    Identifier oldUserId = old.userId();
+    Identifier userId = userId();
+    Identifier oldBotId = old.botId();
+    Identifier botId = botId();
     Preconditions.checkArgument(
         old.userId().equals(userId()) && old.botId().equals(botId()),
         "userId and botId not consistent with this thread state");
   }
 
+  private int compare(int priority1, int priority2){
+    return priority1 > priority2 ? +1 : priority1 < priority2 ? -1 : 0;
+  }
+
   public static <T extends Message> ThreadState<T> of(T message) {
     return new ThreadState<>(message);
   }
@@ -78,8 +82,9 @@ public Identifier botId() {
   }
 
   public T newMessageFromBot(Instant timestamp, String message) {
-    return messageFactory.newMessage(
+    T newMessage = messageFactory.newMessage(
         timestamp, message, botId(), userId(), Identifier.random(), Role.ASSISTANT);
+    return newMessage.withParentMessage(tail());
   }
 
   public T newMessageFromUser(Instant timestamp, String message, Identifier instanceId) {
@@ -97,4 +102,5 @@ public List<T> messages() {
   public T tail() {
     return messages.get(messages.size() - 1);
   }
+
 }

src/main/java/com/meta/cp4m/message/WAMessage.java

@@ -9,6 +9,8 @@
 package com.meta.cp4m.message;
 
 import com.meta.cp4m.Identifier;
+import org.checkerframework.checker.lock.qual.NewObject;
+
 import java.time.Instant;
 
 public record WAMessage(
@@ -17,5 +19,11 @@ public record WAMessage(
     Identifier senderId,
     Identifier recipientId,
     String message,
-    Role role)
-    implements Message {}
+    Role role,
+    Message parentMessage)
+    implements Message {
+    @Override
+    public @NewObject Message withParentMessage(Message parentMessage) {
+        return new WAMessage(timestamp(),instanceId(),senderId(),recipientId(),message(), role(), parentMessage);
+    }
+}

src/main/java/com/meta/cp4m/message/WAMessageHandler.java

@@ -38,6 +38,7 @@ public class WAMessageHandler implements MessageHandler<WAMessage> {
   private static final String API_VERSION = "v17.0";
   private static final JsonMapper MAPPER = Utils.JSON_MAPPER;
   private static final Logger LOGGER = LoggerFactory.getLogger(WAMessageHandler.class);
+  private static final MessageFactory<WAMessage> MESSAGE_FACTORY = MessageFactory.instance(WAMessage.class);
 
   /**
    * <a
@@ -95,15 +96,9 @@ private List<WAMessage> post(Context ctx, WebhookPayload payload) {
                   continue;
                 }
                 TextWebhookMessage textMessage = (TextWebhookMessage) message;
-                waMessages.add(
-                    new WAMessage(
-                        message.timestamp(),
-                        message.id(),
-                        message.from(),
-                        phoneNumberId,
-                        textMessage.text().body(),
-                        Message.Role.USER));
+                WAMessage waMessage = MESSAGE_FACTORY.newMessage(message.timestamp(), textMessage.text().body(), message.from(), phoneNumberId,message.id(), Message.Role.USER);
                 readExecutor.execute(() -> markRead(phoneNumberId, textMessage.id().toString()));
+                waMessages.add(waMessage);
               }
             });
     return waMessages;

src/main/java/com/meta/cp4m/store/ChatStore.java

@@ -8,6 +8,7 @@
 
 package com.meta.cp4m.store;
 
+import com.meta.cp4m.Identifier;
 import com.meta.cp4m.message.Message;
 import com.meta.cp4m.message.ThreadState;
 import java.util.List;
@@ -28,4 +29,6 @@ public interface ChatStore<T extends Message> {
   long size();
 
   List<ThreadState<T>> list();
+
+  ThreadState<T> get(Identifier threadId);
 }

src/main/java/com/meta/cp4m/store/MemoryStore.java

@@ -31,7 +31,7 @@ public class MemoryStore<T extends Message> implements ChatStore<T> {
   }
 
   @Override
-  public ThreadState<T> add(T message) {
+  public ThreadState<T>  add(T message) {
     return this.store
         .asMap()
         .compute(
@@ -53,4 +53,9 @@ public long size() {
   public List<ThreadState<T>> list() {
     return store.asMap().values().stream().toList();
   }
+
+  @Override
+  public ThreadState<T> get(Identifier threadId){
+    return this.store.asMap().get(threadId);
+  }
 }

src/test/java/com/meta/cp4m/message/FBMessageHandlerTest.java

@@ -399,7 +399,7 @@ void chunkingHappens() throws IOException {
         Stream.generate(() -> "0123456789.").limit(300).collect(Collectors.joining(" "));
     FBMessage bigMessage =
         new FBMessage(
-            Instant.now(), Identifier.random(), pageId, Identifier.random(), bigText, Role.USER);
+            Instant.now(), Identifier.random(), pageId, Identifier.random(), bigText, Role.USER,null);
     messageHandler.respond(bigMessage);
     assertThat(requests.size()).isEqualTo(300);
     assertThat(requests).allSatisfy(m -> assertThat(m.body()).contains("0123456789"));

src/test/java/com/meta/cp4m/message/MessageTest.java

@@ -22,8 +22,8 @@ void threadId() {
     Identifier id0 = Identifier.from("0");
     Identifier id1 = Identifier.from("1");
     Identifier id2 = Identifier.from("2");
-    Message message = new FBMessage(timestamp, id0, id1, id2, "", Message.Role.ASSISTANT);
-    Message response = new FBMessage(timestamp, id0, id2, id1, "", Message.Role.ASSISTANT);
+    Message message = new FBMessage(timestamp, id0, id1, id2, "", Message.Role.ASSISTANT, null);
+    Message response = new FBMessage(timestamp, id0, id2, id1, "", Message.Role.ASSISTANT, null);
     assertThat(message.threadId()).isEqualTo(response.threadId());
 
     message =
@@ -33,15 +33,15 @@ void threadId() {
             Identifier.from("12"),
             Identifier.from("34"),
             "",
-            Message.Role.ASSISTANT);
+            Message.Role.ASSISTANT, null);
     response =
         new FBMessage(
             timestamp,
             id0,
             Identifier.from("1"),
             Identifier.from("234"),
             "",
-            Message.Role.ASSISTANT);
+            Message.Role.ASSISTANT, null);
     assertThat(message.threadId()).isNotEqualTo(response.threadId());
   }
 }

src/test/java/com/meta/cp4m/message/ServiceTestHarness.java

@@ -88,12 +88,12 @@ public URI webserverURI() {
 
   public URI serviceURI() {
     try {
-      return URIBuilder.localhost()
+      return URIBuilder.loopbackAddress()
           .appendPath(SERVICE_PATH)
           .setScheme("http")
           .setPort(servicePort())
           .build();
-    } catch (URISyntaxException | UnknownHostException e) {
+    } catch (URISyntaxException e) {
       // this should be impossible
       throw new RuntimeException(e);
     }

src/test/java/com/meta/cp4m/store/MemoryStoreTest.java

@@ -37,7 +37,9 @@ void test() {
             Instant.now(), "", recipientId, senderId, Identifier.random(), Message.Role.USER);
     thread = memoryStore.add(message2);
     assertThat(memoryStore.size()).isEqualTo(1);
-    assertThat(thread.messages()).hasSize(2).contains(message, message2);
+    assertThat(thread.messages()).hasSize(2);
+    assertThat(thread.messages().get(0).instanceId()).isSameAs(message.instanceId());
+    assertThat(thread.messages().get(1).instanceId()).isSameAs(message2.instanceId());
 
     FBMessage message3 =
         messageFactory.newMessage(