add rate limiting middleware

api.go

@@ -39,7 +39,8 @@ func (s *APIServer) Run() error {
 	middlewareChain := MiddlewareChain(
 		RequestLoggerMiddleware,
 		RequireAuthMiddleware,
-		ThrottlingMiddleware(5*time.Second),
+		ThrottlingMiddleware(5*time.Second),      // One request per second
+		RateLimitingMiddleware(3, 1*time.Minute), // Five request per minute
 	)
 
 	server := http.Server{
@@ -108,7 +109,7 @@ func ThrottlingMiddleware(limit time.Duration) Middleware {
 
 			lastTime, exists := lastRequestTime[userID]
 			if exists && time.Since(lastTime) < limit {
-				http.Error(w, "Too Many Requests", http.StatusTooManyRequests)
+				http.Error(w, "Too Many Requests [Throttling Middleware Block Request]", http.StatusTooManyRequests)
 				return
 			}
 
@@ -118,3 +119,54 @@ func ThrottlingMiddleware(limit time.Duration) Middleware {
 		}
 	}
 }
+
+func RateLimitingMiddleware(maxRequests int, duration time.Duration) Middleware {
+	var requestCounts sync.Map
+
+	return func(next http.Handler) http.HandlerFunc {
+		return func(w http.ResponseWriter, r *http.Request) {
+
+			path := r.URL.Path
+			if !strings.Contains(path, "/users/") {
+				http.Error(w, "Invalid URL format", http.StatusBadRequest)
+				return
+			}
+
+			userID := path[len("/users/"):]
+			if userID == "" {
+				http.Error(w, "User ID is required", http.StatusBadRequest)
+				return
+			}
+
+			value, _ := requestCounts.LoadOrStore(userID, &rateLimiter{
+				requestCount: 0,
+				resetTime:    time.Now().Add(duration),
+				mu:           sync.Mutex{},
+			})
+
+			limiter := value.(*rateLimiter)
+
+			limiter.mu.Lock()
+			defer limiter.mu.Unlock()
+
+			if time.Now().After(limiter.resetTime) {
+				limiter.requestCount = 0
+				limiter.resetTime = time.Now().Add(duration)
+			}
+
+			if limiter.requestCount >= maxRequests {
+				http.Error(w, "Too Many Requests [Rate Limiting Middleware Block Request]", http.StatusTooManyRequests)
+				return
+			}
+
+			limiter.requestCount++
+			next.ServeHTTP(w, r)
+		}
+	}
+}
+
+type rateLimiter struct {
+	requestCount int
+	resetTime    time.Time
+	mu           sync.Mutex
+}