[gym_jiminy/common] Support string representation of enums in pipelin…

…e config.

python/gym_jiminy/common/gym_jiminy/common/utils/pipeline.py

@@ -23,9 +23,12 @@
 import gymnasium as gym
 
 import jiminy_py.core as jiminy
+import pinocchio as pin
 from jiminy_py.dynamics import State, Trajectory
 
-from ..bases import (InterfaceJiminyEnv,
+from ..quantities import EnergyGenerationMode
+from ..bases import (QuantityEvalMode,
+                     InterfaceJiminyEnv,
                      InterfaceBlock,
                      InterfaceQuantity,
                      BaseControllerBlock,
@@ -41,6 +44,13 @@
 from ..envs import BaseJiminyEnv
 
 
+ENUM_TYPES = (EnergyGenerationMode,
+              QuantityEvalMode,
+              pin.KinematicLevel)
+ENUM_NAME_TO_MODULE_MAP = {enum_type.__name__: enum_type.__module__.split(".")
+                           for enum_type in ENUM_TYPES}
+
+
 class CompositionConfig(TypedDict, total=False):
     """Store information required for instantiating a given composition, which
     comprises reward components or a termination condition at the time being.
@@ -236,6 +246,34 @@ def build_pipeline(env_config: EnvConfig,
                       an exception if required but not provided.
                       Optional: `None` by default.
     """
+    # Define helper to replace enums string by its corresponding object value
+    def sanitize_enum_string(kwargs: Dict[str, Any]) -> None:
+        """Replace in-place enum string representation with their object
+        counterpart.
+
+        :param kwargs: Nested dictionary of options.
+        """
+        for key, value in kwargs.items():
+            if isinstance(value, dict):
+                sanitize_enum_string(value)
+                continue
+
+            if not isinstance(value, str):
+                continue
+
+            if value == "none":
+                kwargs[key] = None
+                continue
+
+            value_path = value.split(".")
+            enum_type = value_path[-2] if len(value_path) > 1 else None
+            if enum_type in ENUM_NAME_TO_MODULE_MAP.keys():
+                for path_ in ENUM_NAME_TO_MODULE_MAP[enum_type][::-1]:
+                    if path_ not in value_path:
+                        value_path.insert(0, path_)
+                kwargs[key] = locate(".".join(value_path))
+                continue
+
     # Define helper to sanitize composition configuration
     def sanitize_composition_config(composition_config: CompositionConfig,
                                     is_reward: bool) -> None:
@@ -259,6 +297,9 @@ def sanitize_composition_config(composition_config: CompositionConfig,
         # Get its constructor keyword-arguments
         kwargs = composition_config.get("kwargs", {})
 
+        # Special treatment for "none" and enum string
+        sanitize_enum_string(kwargs)
+
         # Special handling for `MixtureReward`
         if is_reward and issubclass(cls, MixtureReward):
             for component_config in kwargs["components"]:
@@ -300,10 +341,8 @@ def build_composition(
         # Get its constructor keyword-arguments
         kwargs = composition_config.get("kwargs", {}).copy()
 
-        # Special treatment for "none"
-        for key, value in kwargs.items():
-            if isinstance(value, str) and value == "none":
-                kwargs[key] = None
+        # Special treatment for "none" and enum string
+        sanitize_enum_string(kwargs)
 
         # Special handling for `MixtureReward`
         if is_reward and issubclass(cls, MixtureReward):
@@ -521,29 +560,9 @@ def build_controller_observer_layer(
         block_kwargs = block_config.get("kwargs", {})
         wrapper_kwargs = wrapper_config.get("kwargs", {})
 
-        # Special treatment for some values
+        # Special treatment for "none" and enum string
         for kwargs in (block_kwargs, wrapper_kwargs):
-            for key, value in kwargs.items():
-                if not isinstance(value, str):
-                    continue
-
-                if value == "none":
-                    kwargs[key] = None
-                    continue
-
-                value_path = value.split(".")
-                enum_type = value_path[-2] if len(value_path) > 1 else None
-                if enum_type in ("QuantityEvalMode", "KinematicLevel"):
-                    module_path: Sequence[str]
-                    if enum_type == "QuantityEvalMode":
-                        module_path = ("gym_jiminy", "common", "bases")
-                    else:
-                        module_path = ("pinocchio",)
-                    for path_ in module_path[::-1]:
-                        if path_ not in value_path:
-                            value_path.insert(0, path_)
-                    kwargs[key] = locate(".".join(value_path))
-                    continue
+            sanitize_enum_string(kwargs)
 
         # Special treatment for "quantity" arg of `QuantityObserver` blocks
         if block_cls_ is not None and issubclass(block_cls_, QuantityObserver):