Update main.py

main.py

@@ -10,6 +10,7 @@ from flask_apscheduler import APScheduler
 import firebase_admin
 from firebase_admin import credentials, db, auth as firebase_auth
 from resend import Emails
+from resend.exceptions import ResendError # <-- ADDED IMPORT
 import logging
 from logging.handlers import RotatingFileHandler
 import time
@@ -61,27 +62,43 @@ Emails.api_key = RESEND_API_KEY
 logger.info("Flask, APScheduler, and Resend initialized.")
 
 
+# === REFACTORED FUNCTION (send_email) ===
 def send_email(to, subject, html):
-    """Sends an email and provides detailed error logging."""
+    """Sends an email with sanitized input and detailed error logging."""
     try:
+        # --- FIX: Sanitize the email address to remove leading/trailing whitespace ---
+        clean_to = to.strip()
+        if not clean_to:
+            logger.error("Attempted to send email to an empty address.")
+            return None
+
         response = Emails.send({
             "from": "Admin <admin@resend.dev>",
-            "to": to,
+            "to": clean_to, # Use the cleaned email address
             "subject": subject,
             "html": html
         })
         if response is None:
-            logger.warning(f"Email API returned None for recipient {to}. Check Resend dashboard for suppression list.")
+            logger.warning(f"Email API returned None for recipient {clean_to}. Check Resend dashboard for suppression list.")
             return None
-        logger.info(f"Email sent successfully to {to}. Response ID: {response.get('id')}")
+        logger.info(f"Email sent successfully to {clean_to}. Response ID: {response.get('id')}")
         return response
+    # --- FIX: More specific error catching for Resend ---
+    except ResendError as e:
+        logger.error(
+            f"A Resend API error occurred for recipient '{to}': "
+            f"Code: {e.code}, Type: {e.error_type}, Message: {e.message}",
+            exc_info=True
+        )
+        return None
     except Exception:
-        # IMPROVED LOGGING: This will now log the full traceback to your log file
-        logger.error(f"Caught exception while sending email to {to}", exc_info=True)
+        # Fallback for any other unexpected errors
+        logger.error(f"An unexpected exception occurred while sending email to '{to}'", exc_info=True)
         return None
 
+
 def send_rotation_notification(job_id, shift_record):
-    """Sends email notification for rotation to all admins with rate-limiting prevention."""
+    """Sends email notification for rotation to all admins."""
     try:
         job_ref = db.reference(f"jobs/{job_id}")
         job_data = job_ref.get()
@@ -121,7 +138,7 @@ def send_rotation_notification(job_id, shift_record):
         for admin_email in ADMIN_EMAILS:
             logger.info(f"Sending rotation notification to {admin_email}...")
             send_email(admin_email, subject, html_content)
-            time.sleep(1)
+            time.sleep(1) # Rate-limit prevention
     except Exception as e:
         logger.error(f"Error building rotation notification for job {job_id}", exc_info=True)