Fix error with matchmaking service

Author: bensohh

apps/matching-service/handlers/websocket.go

@@ -24,7 +24,9 @@ var (
 	activeConnections = make(map[string]*websocket.Conn)
 	// A map to hold user's match ctx cancel function
 	matchContexts = make(map[string]context.CancelFunc)
-	mu            sync.Mutex // Mutex for thread-safe access to activeConnections
+	// A map to hold user's match channels
+	matchFoundChannels = make(map[string]chan models.MatchFound)
+	mu                 sync.Mutex // Mutex for thread-safe access to activeConnections
 )
 
 // handleConnections manages WebSocket connections and matching logic.
@@ -67,6 +69,9 @@ func HandleWebSocketConnections(w http.ResponseWriter, r *http.Request) {
 	activeConnections[matchRequest.Username] = ws
 	matchCtx, matchCancel := context.WithCancel(context.Background())
 	matchContexts[matchRequest.Username] = matchCancel
+
+	matchFoundChan := make(chan models.MatchFound)
+	matchFoundChannels[matchRequest.Username] = matchFoundChan
 	mu.Unlock()
 
 	// Create a context for cancellation
@@ -84,11 +89,9 @@ func HandleWebSocketConnections(w http.ResponseWriter, r *http.Request) {
 	}
 	defer timeoutCancel()
 
-	matchFoundChan := make(chan models.MatchFound)
-
 	// Start goroutines for handling messages and performing matching.
 	go processes.ReadMessages(ws, ctx, cancel)
-	go processes.PerformMatching(matchRequest, ctx, matchFoundChan) // Perform matching
+	go processes.PerformMatching(matchRequest, context.Background(), matchFoundChannels) // Perform matching
 
 	// Wait for a match, timeout, or cancellation.
 	waitForResult(ws, ctx, timeoutCtx, matchCtx, matchFoundChan, matchRequest.Username)
@@ -127,29 +130,47 @@ func waitForResult(ws *websocket.Conn, ctx, timeoutCtx, matchCtx context.Context
 		log.Println("Matching cancelled")
 		// Cleanup Redis
 		processes.CleanUpUser(processes.GetRedisClient(), username, context.Background())
+		// Remove the match context and active
+		if _, exists := matchContexts[username]; exists {
+			delete(matchContexts, username)
+		}
+		if _, exists := activeConnections[username]; exists {
+			delete(activeConnections, username)
+		}
+		if _, exists := matchFoundChannels[username]; exists {
+			delete(matchFoundChannels, username)
+		}
+
 		return
 	case <-timeoutCtx.Done():
 		log.Println("Connection timed out")
 		// Cleanup Redis
 		processes.CleanUpUser(processes.GetRedisClient(), username, context.Background())
+		// Remove the match context and active
+		if _, exists := matchContexts[username]; exists {
+			delete(matchContexts, username)
+		}
+		if _, exists := activeConnections[username]; exists {
+			delete(activeConnections, username)
+		}
+		if _, exists := matchFoundChannels[username]; exists {
+			delete(matchFoundChannels, username)
+		}
+
 		sendTimeoutResponse(ws)
 		return
 	case <-matchCtx.Done():
-		log.Println("Match found for user HEREEE: " + username)
+		log.Println("Match found for user: " + username)
 		return
 	case result, ok := <-matchFoundChan:
 		if !ok {
 			// Channel closed without a match, possibly due to context cancellation
 			log.Println("Match channel closed without finding a match")
 			return
 		}
-		log.Println("Match found for user: " + result.User)
+		log.Println("Match found for user: " + username)
 		// Notify the users about the match
 		notifyMatch(result.User, result.MatchedUser, result)
-
-		// if err := ws.WriteJSON(result); err != nil {
-		// 	log.Printf("write error: %v", err)
-		// }
 		return
 	}
 }
@@ -185,13 +206,22 @@ func notifyMatch(username, matchedUsername string, result models.MatchFound) {
 	}
 
 	// Remove the match context for both users and cancel for matched user
-	if _, exists := matchContexts[username]; exists {
+	if cancelFunc, exists := matchContexts[username]; exists {
+		cancelFunc()
 		delete(matchContexts, username)
 	}
 
-	if cancelFunc, exists := matchContexts[matchedUsername]; exists {
+	if cancelFunc2, exists := matchContexts[matchedUsername]; exists {
+		cancelFunc2()
 		delete(matchContexts, matchedUsername)
-		defer cancelFunc() // TODO: CancelFunction here is not causing the matchCtx to be done
+	}
+
+	// Remove the match channels
+	if _, exists := matchFoundChannels[username]; exists {
+		delete(matchFoundChannels, username)
+	}
+	if _, exists := matchFoundChannels[matchedUsername]; exists {
+		delete(matchFoundChannels, matchedUsername)
 	}
 
 	// Remove users from the activeConnections map

apps/matching-service/processes/match.go

@@ -45,7 +45,7 @@ func getPortNumber(addr string) (int64, error) {
 	return port, nil
 }
 
-func PerformMatching(matchRequest models.MatchRequest, ctx context.Context, matchFoundChan chan models.MatchFound) {
+func PerformMatching(matchRequest models.MatchRequest, ctx context.Context, matchFoundChannels map[string]chan models.MatchFound) {
 	// Acquire mutex
 	mu.Lock()
 	// Defer unlocking the mutex
@@ -73,15 +73,15 @@ func PerformMatching(matchRequest models.MatchRequest, ctx context.Context, matc
 		// Peek at the user queue
 		username, err := redisClient.LIndex(context.Background(), "matchmaking_queue", 0).Result()
 		if err != nil {
-			// log.Println("Error peeking user from queue:", err)
+			log.Println("Error peeking user from queue:", err)
 			time.Sleep(1 * time.Second)
 			continue
 		}
 
 		// log.Printf("Performing matching for user: %s", username)
 		matchedUsername, matchedTopic, matchedDifficulty, err := FindMatchingUser(redisClient, username, ctx)
 		if err != nil {
-			// log.Println("Error finding matching user:", err)
+			log.Println("Error finding matching user:", err)
 			time.Sleep(1 * time.Second)
 			continue
 		}
@@ -111,7 +111,7 @@ func PerformMatching(matchRequest models.MatchRequest, ctx context.Context, matc
 			}
 
 			// Signal that a match has been found
-			matchFoundChan <- models.MatchFound{
+			matchFoundChannels[username] <- models.MatchFound{
 				Type:        "match_found",
 				MatchID:     matchId,
 				User:        username,