Update utils.py

utils.py

@@ -2,6 +2,49 @@ import os
 from datetime import datetime, timedelta
 import jwt
 
+# ===================== Rate Limiting =====================
+
+class RateLimiter:
+    """Simple in-memory rate limiter"""
+    def __init__(self):
+        self.requests = {}  # {key: [(timestamp, count)]}
+        self.lock = threading.Lock()
+    
+    def is_allowed(self, key: str, max_requests: int, window_seconds: int) -> bool:
+        """Check if request is allowed"""
+        with self.lock:
+            now = datetime.now(timezone.utc)
+            
+            if key not in self.requests:
+                self.requests[key] = []
+            
+            # Remove old entries
+            cutoff = now.timestamp() - window_seconds
+            self.requests[key] = [
+                (ts, count) for ts, count in self.requests[key]
+                if ts > cutoff
+            ]
+            
+            # Count requests in window
+            total = sum(count for _, count in self.requests[key])
+            
+            if total >= max_requests:
+                return False
+            
+            # Add this request
+            self.requests[key].append((now.timestamp(), 1))
+            return True
+    
+    def reset(self, key: str):
+        """Reset rate limit for key"""
+        with self.lock:
+            if key in self.requests:
+                del self.requests[key]
+
+# Create global rate limiter instance
+import threading
+rate_limiter = RateLimiter()
+
 # ===================== JWT Config =====================
 def get_jwt_config():
     """Get JWT configuration based on environment"""
@@ -49,4 +92,30 @@ def verify_token(credentials: HTTPAuthorizationCredentials = Depends(security))
     except jwt.ExpiredSignatureError:
         raise HTTPException(status_code=401, detail="Token expired")
     except jwt.InvalidTokenError:
-        raise HTTPException(status_code=401, detail="Invalid token")
+        raise HTTPException(status_code=401, detail="Invalid token")
+
+# ===================== Utility Functions =====================
+
+def truncate_string(text: str, max_length: int = 100, suffix: str = "...") -> str:
+    """Truncate string to max length"""
+    if len(text) <= max_length:
+        return text
+    return text[:max_length - len(suffix)] + suffix
+
+def format_file_size(size_bytes: int) -> str:
+    """Format file size in human readable format"""
+    for unit in ['B', 'KB', 'MB', 'GB', 'TB']:
+        if size_bytes < 1024.0:
+            return f"{size_bytes:.2f} {unit}"
+        size_bytes /= 1024.0
+    return f"{size_bytes:.2f} PB"
+
+def is_safe_path(path: str, base_path: str) -> bool:
+    """Check if path is safe (no directory traversal)"""
+    import os
+    # Resolve to absolute paths
+    base = os.path.abspath(base_path)
+    target = os.path.abspath(os.path.join(base, path))
+    
+    # Check if target is under base
+    return target.startswith(base)