VED-755: Refactor existing id_sync codebase

Author: Akol125

lambdas/id_sync/src/id_sync.py

@@ -26,8 +26,6 @@ def handler(event_data: Dict[str, Any], _context) -> Dict[str, Any]:
 
         logger.info("id_sync processing event with %d records", len(records))
 
-        # Process records in order. Let any unexpected exception bubble to the outer handler
-        # so tests that expect a wrapped IdSyncException keep working.
         results = [process_record(record) for record in records]
         nhs_numbers = [result["nhs_number"] for result in results]
         error_count = sum(1 for result in results if result.get("status") == "error")
@@ -36,9 +34,11 @@ def handler(event_data: Dict[str, Any], _context) -> Dict[str, Any]:
             raise IdSyncException(message=f"Processed {len(records)} records with {error_count} errors",
                                   nhs_numbers=nhs_numbers)
 
-        response = {"status": "success",
-                    "message": f"Successfully processed {len(records)} records",
-                    "nhs_numbers": nhs_numbers}
+        response = {
+            "status": "success",
+            "message": f"Successfully processed {len(records)} records",
+            "nhs_numbers": nhs_numbers
+            }
 
         logger.info("id_sync handler completed: %s", response)
         return response

lambdas/id_sync/src/pds_details.py

@@ -13,6 +13,7 @@
 safe_tmp_dir = tempfile.mkdtemp(dir="/tmp")  # NOSONAR
 
 
+# Get Patient details from external service PDS using NHS number from MNS notification
 def pds_get_patient_details(nhs_number: str) -> dict:
     try:
         logger.info(f"get patient details. nhs_number: {nhs_number}")
@@ -34,6 +35,7 @@ def pds_get_patient_details(nhs_number: str) -> dict:
         raise IdSyncException(message=msg, exception=e)
 
 
+# Extract Patient identifier value from PDS patient details
 def pds_get_patient_id(nhs_number: str) -> str:
     """
     Get PDS patient ID from NHS number.

lambdas/id_sync/src/record_processor.py

@@ -1,26 +1,20 @@
-'''
-    record Processor
-'''
 from common.clients import logger
-from typing import Optional
+from typing import Dict, Any
 from pds_details import pds_get_patient_id
 from ieds_db_operations import ieds_check_exist, ieds_update_patient_id
 import json
 import ast
 
 
-def process_record(event_record):
+def process_record(event_record) -> Dict[str, Any]:
 
     logger.info("process_record. Processing record: %s", event_record)
     body_text = event_record.get('body', '')
-    # convert body to json
     if isinstance(body_text, str):
         try:
-            # Try JSON first
             body = json.loads(body_text)
         except json.JSONDecodeError:
             try:
-                # Fall back to Python dict syntax
                 body = ast.literal_eval(body_text)
             except (ValueError, SyntaxError):
                 logger.error("Failed to parse body: %s", body_text)
@@ -30,26 +24,25 @@ def process_record(event_record):
     nhs_number = body.get("subject")
     logger.info("process record NHS number: %s", nhs_number)
     if nhs_number:
+        if not _is_valid_nhs(nhs_number):
+            logger.error("Invalid NHS number format: %s", nhs_number)
+            return {"status": "error", "message": "Invalid NHS number format", "nhs_number": nhs_number}
         return process_nhs_number(nhs_number)
     else:
         logger.info("No NHS number found in event record")
         return {"status": "error", "message": "No NHS number found in event record"}
 
 
-def process_nhs_number(nhs_number: str) -> Optional[str]:
+def process_nhs_number(nhs_number: str) -> Dict[str, Any]:
     # get patient details from PDS
-    logger.info(f"process_nhs_number. Processing NHS number: {nhs_number}")
-    patient_details_id = pds_get_patient_id(nhs_number)
+    new_nhs_number = pds_get_patient_id(nhs_number)
 
     base_log_data = {"nhs_number": nhs_number}
-    if patient_details_id:
-        logger.info(f"process_nhs_number. Patient details ID: {patient_details_id}")
-        # if patient NHS != id, update patient index of vax events to new number
-        if patient_details_id != nhs_number and patient_details_id:
-            logger.info(f"process_nhs_number. Update patient ID from {nhs_number} to {patient_details_id}")
+    if new_nhs_number:
+        if new_nhs_number != nhs_number:
+            logger.info("process_nhs_number. Update patient ID from %s to %s", nhs_number, new_nhs_number)
             if ieds_check_exist(nhs_number):
-                logger.info("process_nhs_number. IEDS record found, updating patient ID")
-                response = ieds_update_patient_id(nhs_number, patient_details_id)
+                response = ieds_update_patient_id(nhs_number, new_nhs_number)
             else:
                 logger.info("process_nhs_number. No ieds record found for: %s", nhs_number)
                 response = {"status": "success", "message": f"No records returned for ID: {nhs_number}"}
@@ -59,3 +52,8 @@ def process_nhs_number(nhs_number: str) -> Optional[str]:
         response = {"status": "success", "message": f"No patient ID found for NHS number: {nhs_number}"}
     response.update(base_log_data)
     return response
+
+
+def _is_valid_nhs(nhs: str) -> bool:
+    """Basic validation: NHS number must be 10 digits. (Optional: add MOD11 check later)"""
+    return isinstance(nhs, str) and nhs.isdigit() and len(nhs) == 10