Add comprehensive error handling and state management to cadence_agent.py

cadence_agent.py

@@ -253,4 +253,72 @@ class CadenceAgent:
         
         # TODO: Load from actual data sources
         logger.info("Suppression lists loaded")
-        return suppression_lists
+        return suppression_lists
+    
+    def _load_cadence_states(self) -> None:
+        """
+        Load persisted cadence states from disk.
+        
+        Error handling:
+        - FileNotFoundError: Log and continue (first run)
+        - JSONDecodeError: Log error, backup corrupt file, continue
+        - Exception: Log error and continue with empty state
+        """
+        try:
+            if self.state_file.exists():
+                with open(self.state_file, 'r') as f:
+                    states_data = json.load(f)
+                    # Reconstruct CadenceState objects
+                    for lead_id, state_dict in states_data.items():
+                        # Convert string dates back to datetime objects
+                        state_dict['start_date'] = datetime.fromisoformat(
+                            state_dict['start_date']
+                        )
+                        if state_dict.get('last_touchpoint_date'):
+                            state_dict['last_touchpoint_date'] = datetime.fromisoformat(
+                                state_dict['last_touchpoint_date']
+                            )
+                        if state_dict.get('next_touchpoint_date'):
+                            state_dict['next_touchpoint_date'] = datetime.fromisoformat(
+                                state_dict['next_touchpoint_date']
+                            )
+                        # Reconstruct EngagementLevel enum
+                        state_dict['engagement_level'] = EngagementLevel(
+                            state_dict['engagement_level']
+                        )
+                        self.cadence_states[lead_id] = CadenceState(**state_dict)
+                logger.info(f"Loaded {len(self.cadence_states)} cadence states")
+        except FileNotFoundError:
+            logger.info("No existing cadence states found (first run)")
+        except json.JSONDecodeError as e:
+            logger.error(f"Corrupt state file detected: {str(e)}")
+            # Backup corrupt file
+            backup_file = self.state_file.with_suffix('.json.corrupt')
+            self.state_file.rename(backup_file)
+            logger.info(f"Backed up corrupt state file to {backup_file}")
+        except Exception as e:
+            logger.error(f"Unexpected error loading states: {str(e)}")
+    
+    def _initialize_activity_log(self) -> None:
+        """
+        Initialize activity log CSV file.
+        
+        Error handling:
+        - PermissionError: Log error and raise (critical)
+        - OSError: Log error and raise (critical)
+        """
+        try:
+            if not self.activity_log.exists():
+                with open(self.activity_log, 'w', newline='') as f:
+                    writer = csv.writer(f)
+                    writer.writerow([
+                        'timestamp', 'lead_id', 'step', 'channel', 'template',
+                        'status', 'engagement_level', 'error_message'
+                    ])
+                logger.info(f"Activity log initialized at {self.activity_log}")
+        except (PermissionError, OSError) as e:
+            logger.error(f"Failed to initialize activity log: {str(e)}")
+            raise
+        except Exception as e:
+            logger.error(f"Unexpected error initializing activity log: {str(e)}")
+            raise