Implement custom to_json function for DeviceMetadata

code/iottb/models/device_metadata_model.py

@@ -49,7 +49,7 @@ class DeviceMetadata:
 
         with device_meta_filename.open('r') as file:
             metadata_json = json.load(file)
-        metadata_model_obj = cls.model_validate_json(metadata_json)
+        metadata_model_obj = cls.from_json(metadata_json)
         return metadata_model_obj
 
     def save_to_json(self, file_path: Path):
@@ -57,18 +57,42 @@ class DeviceMetadata:
         if file_path.is_file():
             print(f"File {file_path} already exists, update instead.")
             return ReturnCodes.FILE_ALREADY_EXISTS
-        metadata = self.model_dump_json(indent=2)
+        metadata = self.to_json(indent=2)
         with file_path.open('w') as file:
             json.dump(metadata, file)
             return ReturnCodes.SUCCESS
 
 
     @classmethod
-    def model_validate_json(cls, metadata_json):
+    def from_json(cls, metadata_json):
         pass
 
-    def model_dump_json(self, indent):
-        pass
+    def to_json(self, indent=2):
+        # TODO: atm almost exact copy as in CaptureMetadata
+        data = {}
+
+        fields = {
+            "device_name": True,
+            "device_short_name": True,
+            "device_id": True,
+            "date_created": True,
+            "device_root_path": True,
+            "aliases": False,
+            "device_type": False,
+            "device_serial_number": False,
+            "device_firmware_version": False,
+            "date_updated": True,
+            "capture_files": False,
+        }
+
+        for field, is_mandatory in fields.items():
+            value = getattr(self, field, None)
+            if value not in [None, ""] or is_mandatory:
+                if value in [None, ""] and is_mandatory:
+                    raise ValueError(f"Field {field} is required and cannot be empty.")
+                data[field] = str(value) if not isinstance(value, Path) else value
+        logger.debug(f"Device metadata: {data}")
+        return json.dumps(data, indent=indent)
 
 
 def dir_contains_device_metadata(dir_path: Path):