add userstatus endpoint

Author: h908714124

src/main/java/com/bernd/ChatController.java

@@ -3,32 +3,39 @@
 import com.bernd.model.Chat;
 import com.bernd.model.ChatMessage;
 import com.bernd.model.ChatRequest;
+import com.bernd.model.Status;
+import com.bernd.model.StatusMap;
+import com.bernd.model.UserStatus;
 import com.bernd.model.UsersMessage;
 import com.bernd.util.Auth;
-import org.springframework.http.ResponseEntity;
+import com.bernd.util.Sender;
+import java.security.Principal;
+import java.util.List;
+import java.util.Map;
 import org.springframework.messaging.core.MessageSendingOperations;
 import org.springframework.messaging.handler.annotation.MessageMapping;
 import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.ResponseBody;
 
-import java.security.Principal;
-import java.util.ArrayList;
-import java.util.TreeSet;
-import java.util.concurrent.atomic.AtomicInteger;
-
 @Controller
 public class ChatController {
 
   private final Chats chats;
   private final MessageSendingOperations<String> operations;
+  private final Sender sender;
+  private final StatusMap statusMap = new StatusMap();
+  private long lastScan;
+  private static final long SCAN_TIMEOUT = 120 * 1000;
 
   ChatController(
       Chats chats,
-      MessageSendingOperations<String> operations) {
+      MessageSendingOperations<String> operations,
+      Sender sender) {
     this.chats = chats;
     this.operations = operations;
+    this.sender = sender;
   }
 
   @ResponseBody
@@ -37,8 +44,8 @@ public Chat getChat(@PathVariable String id) {
     return chats.get(id);
   }
 
-  @MessageMapping("/chat/send/")
-  public ResponseEntity<?> sendChat(ChatRequest chatRequest, Principal principal) {
+  @MessageMapping("/chat/send")
+  public void sendChat(ChatRequest chatRequest, Principal principal) {
     String user = Auth.getPrincipal(principal);
     Chat chat = chats.get(chatRequest.id());
     ChatMessage message = new ChatMessage(chat.counter().getAndIncrement(), chatRequest.message(), user);
@@ -47,6 +54,25 @@ public ResponseEntity<?> sendChat(ChatRequest chatRequest, Principal principal)
       operations.convertAndSend("/topic/users/" + chat.id(), new UsersMessage(chat.users()));
     }
     operations.convertAndSend("/topic/chat/" + chat.id(), message);
-    return ResponseEntity.ok().build();
+  }
+
+  @MessageMapping("/chat/status")
+  public void updateStatus(Status status, Principal principal) {
+    String user = Auth.getPrincipal(principal);
+    UserStatus old = statusMap.put(user, UserStatus.create(status.room()));
+    if (lastScan + SCAN_TIMEOUT < System.currentTimeMillis()) {
+      Map<String, List<String>> allRooms = statusMap.allRooms();
+      for (Map.Entry<String, List<String>> e : allRooms.entrySet()) {
+        String room = e.getKey();
+        List<String> users = e.getValue();
+        sender.sendUsers(room, users);
+      }
+      lastScan = System.currentTimeMillis();
+    } else if (old == null) {
+      sender.sendUsers(status.room(), statusMap.usersInRoom(status.room()));
+    } else if (!old.room().equals(status.room())) {
+      sender.sendUsers(status.room(), statusMap.usersInRoom(status.room()));
+      sender.sendUsers(status.room(), statusMap.usersInRoom(old.room()));
+    }
   }
 }

src/main/java/com/bernd/model/Status.java

@@ -1,4 +1,4 @@
 package com.bernd.model;
 
-public record Status(String name, String status) {
-}
+public record Status(String room) {
+}

src/main/java/com/bernd/model/StatusMap.java

@@ -0,0 +1,45 @@
+package com.bernd.model;
+
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+public final class StatusMap {
+  private static final long USER_TIMEOUT = 90 * 1000;
+  private final Map<String, UserStatus> map = new LinkedHashMap<>();
+
+  public UserStatus put(String user, UserStatus status) {
+    return map.put(user, status);
+  }
+
+  public List<String> usersInRoom(String room) {
+    List<String> result = new ArrayList<>();
+    for (Map.Entry<String, UserStatus> e : map.entrySet()) {
+      if (e.getValue().room().equals(room)) {
+        result.add(e.getKey());
+      }
+    }
+    return result;
+  }
+
+  public Map<String, List<String>> allRooms() {
+    long current = System.currentTimeMillis();
+    Map<String, List<String>> result = new LinkedHashMap<>();
+    List<String> remove = new ArrayList<>();
+    for (Map.Entry<String, UserStatus> e : map.entrySet()) {
+      UserStatus status = e.getValue();
+      String user = e.getKey();
+      if (status.lastSeen() + USER_TIMEOUT < current) {
+        remove.add(user);
+      } else {
+        result.computeIfAbsent(status.room(), key -> new ArrayList<>())
+            .add(user);
+      }
+    }
+    for (String user : remove) {
+      map.remove(user);
+    }
+    return result;
+  }
+}

src/main/java/com/bernd/model/UserStatus.java

@@ -0,0 +1,7 @@
+package com.bernd.model;
+
+public record UserStatus(String room, long lastSeen) {
+  public static UserStatus create(String room) {
+    return new UserStatus(room, System.currentTimeMillis());
+  }
+}

src/main/java/com/bernd/model/UsersMessage.java

@@ -1,7 +1,7 @@
 package com.bernd.model;
 
-import java.util.Set;
+import java.util.Collection;
 
 public record UsersMessage(
-    Set<String> users) {
+    Collection<String> users) {
 }

src/main/java/com/bernd/util/Sender.java

@@ -0,0 +1,19 @@
+package com.bernd.util;
+
+import com.bernd.model.UsersMessage;
+import java.util.Collection;
+import org.springframework.messaging.core.MessageSendingOperations;
+import org.springframework.stereotype.Component;
+
+@Component
+public final class Sender {
+  private final MessageSendingOperations<String> operations;
+
+  Sender(MessageSendingOperations<String> operations) {
+    this.operations = operations;
+  }
+
+  public void sendUsers(String room, Collection<String> users) {
+    operations.convertAndSend("/topic/users/" + room, new UsersMessage(users));
+  }
+}