Update main.py

main.py

@@ -21,6 +21,9 @@ from sozo_gen import (
     deepgram_tts
 )
 import logging
+import time
+import threading
+
 # -----------------------------------------------------------------------------
 # 1. CONFIGURATION & INITIALIZATION
 # -----------------------------------------------------------------------------
@@ -69,11 +72,37 @@ def is_valid_email(email):
     regex = r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$'
     return re.match(regex, email) is not None
 
+
+
+# Global rate limiter for Resend API
+class ResendRateLimiter:
+    def __init__(self, requests_per_second=1):
+        self.requests_per_second = requests_per_second
+        self.min_interval = 1.0 / requests_per_second
+        self.last_request_time = 0
+        self.lock = threading.Lock()
+    
+    def wait_if_needed(self):
+        with self.lock:
+            current_time = time.time()
+            time_since_last_request = current_time - self.last_request_time
+            
+            if time_since_last_request < self.min_interval:
+                sleep_time = self.min_interval - time_since_last_request
+                logger.info(f"Rate limiting: waiting {sleep_time:.2f} seconds before sending email")
+                time.sleep(sleep_time)
+            
+            self.last_request_time = time.time()
+
+# Global instance - initialize once
+resend_rate_limiter = ResendRateLimiter(requests_per_second=1)
+
 def _send_notification(user_id, user_email, message_content, send_email=False, email_subject=None, email_body=None):
     """
     Internal helper to send notifications.
     Creates an in-app notification in Firebase and optionally sends an email via Resend.
     If user_id is None, it will only attempt to send an email.
+    Rate limited to 1 email per second to respect Resend API limits.
     """
     timestamp = datetime.now(timezone.utc).isoformat()
     
@@ -100,6 +129,9 @@ def _send_notification(user_id, user_email, message_content, send_email=False, e
             logger.error("RESEND_API_KEY is not configured. Cannot send email.")
             return False
         
+        # Apply rate limiting before making the request
+        resend_rate_limiter.wait_if_needed()
+        
         # Clean the API key (remove any whitespace)
         api_key = RESEND_API_KEY.strip()
         
@@ -133,7 +165,20 @@ def _send_notification(user_id, user_email, message_content, send_email=False, e
             logger.debug(f"Response headers: {dict(response.headers)}")
             logger.debug(f"Response content: {response.text}")
             
-            if response.status_code == 401:
+            # Handle rate limiting response
+            if response.status_code == 429:
+                logger.warning(f"Rate limit hit despite internal limiting. Response: {response.text}")
+                # Extract retry-after if available
+                retry_after = response.headers.get('retry-after')
+                if retry_after:
+                    logger.info(f"Server requested retry after {retry_after} seconds")
+                    time.sleep(float(retry_after))
+                    # Retry once
+                    response = requests.post("https://api.resend.com/emails", headers=headers, json=payload)
+                    response.raise_for_status()
+                else:
+                    return False
+            elif response.status_code == 401:
                 logger.error("=== RESEND 401 UNAUTHORIZED DEBUG ===")
                 logger.error(f"API Key starts correctly: {api_key.startswith('re_')}")
                 logger.error(f"API Key length: {len(api_key)} (should be ~40 chars)")
@@ -161,6 +206,62 @@ def _send_notification(user_id, user_email, message_content, send_email=False, e
             return False
             
     return True
+
+
+# Alternative: Batch email sending function for multiple emails
+def send_batch_notifications(notifications_list):
+    """
+    Send multiple notifications with proper rate limiting.
+    
+    Args:
+        notifications_list: List of dicts with keys:
+            - user_id (optional)
+            - user_email
+            - message_content
+            - send_email (bool)
+            - email_subject (optional)
+            - email_body (optional)
+    
+    Returns:
+        dict: Results with success/failure counts
+    """
+    results = {
+        'total': len(notifications_list),
+        'successful': 0,
+        'failed': 0,
+        'errors': []
+    }
+    
+    logger.info(f"Starting batch notification send for {results['total']} notifications")
+    start_time = time.time()
+    
+    for i, notification in enumerate(notifications_list):
+        try:
+            success = _send_notification(
+                user_id=notification.get('user_id'),
+                user_email=notification.get('user_email'),
+                message_content=notification.get('message_content'),
+                send_email=notification.get('send_email', False),
+                email_subject=notification.get('email_subject'),
+                email_body=notification.get('email_body')
+            )
+            
+            if success:
+                results['successful'] += 1
+            else:
+                results['failed'] += 1
+                results['errors'].append(f"Notification {i+1} failed")
+                
+        except Exception as e:
+            results['failed'] += 1
+            results['errors'].append(f"Notification {i+1} error: {str(e)}")
+            logger.error(f"Unexpected error processing notification {i+1}: {e}")
+    
+    elapsed_time = time.time() - start_time
+    logger.info(f"Batch notification completed in {elapsed_time:.2f} seconds. "
+                f"Success: {results['successful']}, Failed: {results['failed']}")
+    
+    return results
 # -----------------------------------------------------------------------------
 # 3. AUTHENTICATION & USER MANAGEMENT
 # -----------------------------------------------------------------------------