Attempt to fix the relays projection in a generic way.

opensensor/collection_apis.py

@@ -8,6 +8,7 @@
 from fastapi_pagination.default import Params as BaseParams
 from fief_client import FiefUserInfo
 from pydantic import BaseModel
+from pydantic.fields import ModelField
 
 from opensensor.collections import (
     CO2,
@@ -197,9 +198,19 @@ def get_nested_fields(model: Type[BaseModel]) -> Dict[str, Type[BaseModel]]:
     return nested_fields
 
 
+def is_list_of_models(field: ModelField) -> bool:
+    if field.shape != 2:  # 2 represents a list shape in Pydantic
+        return False
+    args = field.sub_fields[0].type_.__args__
+    return args and is_pydantic_model(args[0])
+
+
+def get_list_item_type(field: ModelField) -> Type[BaseModel]:
+    return field.sub_fields[0].type_.__args__[0]
+
+
 def create_nested_pipeline(model: Type[BaseModel], prefix=""):
     logger.debug(f"Creating nested pipeline for model: {model.__name__}, prefix: {prefix}")
-    nested_fields = get_nested_fields(model)
     match_conditions = {}
     pipeline = {
         "timestamp": "$timestamp",
@@ -218,24 +229,13 @@ def create_nested_pipeline(model: Type[BaseModel], prefix=""):
             unit_field_name = f"{prefix}{mongo_field}_unit"
             pipeline["unit"] = f"${unit_field_name}"
             match_conditions[unit_field_name] = {"$exists": True}
-        elif field_name in nested_fields:
-            nested_type = nested_fields[field_name]
-            if get_origin(field.type_) is List:
-                # Handle array of nested objects
-                nested_pipeline, nested_match = create_nested_pipeline(nested_type, "")
-                pipeline[field_name] = {
-                    "$map": {
-                        "input": f"${full_mongo_field_name}",
-                        "as": "item",
-                        "in": nested_pipeline,
-                    }
-                }
-                match_conditions[full_mongo_field_name] = {"$exists": True, "$ne": []}
-            else:
-                # Handle nested object
-                nested_pipeline, nested_match = create_nested_pipeline(nested_type, "")
-                pipeline[field_name] = nested_pipeline
-                match_conditions.update({f"{field_name}.{k}": v for k, v in nested_match.items()})
+        elif is_list_of_models(field):
+            item_model = get_list_item_type(field)
+            nested_pipeline, nested_match = create_nested_pipeline(item_model, "")
+            pipeline[field_name] = {
+                "$map": {"input": f"${full_mongo_field_name}", "as": "item", "in": nested_pipeline}
+            }
+            match_conditions[full_mongo_field_name] = {"$exists": True, "$ne": []}
         else:
             # Handle simple field
             pipeline[field_name] = f"${full_mongo_field_name}"