Build [v1.9.19]

backend/db_manager.py

@@ -136,3 +136,36 @@ class DbManager:
         except Exception as e:
             logger.error(f"[DB] Restore failed: {str(e)}")
             raise Exception(f"Restore failed: {str(e)}")
+
+    @staticmethod
+    def export_db() -> str:
+        """Returns the path to the active database file for download."""
+        active_db_path = os.path.join(DATA_DIR, "inventory.db")
+        if not os.path.exists(active_db_path):
+            raise Exception("Database file not found")
+        return active_db_path
+
+    @staticmethod
+    def import_db(file_bytes: bytes, db: Session, user_id: int) -> bool:
+        """
+        Overwrites the active database with the provided file bytes.
+        Creates a safety rollback backup first.
+        """
+        active_db_path = os.path.join(DATA_DIR, "inventory.db")
+        
+        try:
+            # 1. Safety backup
+            DbManager.create_backup(db, label="import_rollback", user_id=user_id)
+            
+            # 2. Close pool connections
+            engine.dispose()
+            
+            # 3. Write new file
+            with open(active_db_path, "wb") as f:
+                f.write(file_bytes)
+                
+            logger.warning(f"[DB] IMPORT COMPLETED by user_id={user_id}")
+            return True
+        except Exception as e:
+            logger.error(f"[DB] Import failed: {str(e)}")
+            raise Exception(f"Import failed: {str(e)}")