Initial commit

netbox_services/engine/registry.py

@@ -0,0 +1,64 @@
+"""Registry for selectors and allocators — pluggable extension points."""
+
+_selectors = {}
+_allocators = {}
+
+
+class RegistryError(Exception):
+    pass
+
+
+class SelectorNotFoundError(RegistryError):
+    pass
+
+
+class AllocatorNotFoundError(RegistryError):
+    pass
+
+
+def register_selector(type_name):
+    def decorator(cls):
+        _selectors[type_name] = cls
+        cls.type = type_name
+        return cls
+    return decorator
+
+
+def get_selector(spec):
+    if not spec or not isinstance(spec, dict):
+        raise ValueError(f"Invalid selector spec: {spec!r}")
+    type_name = spec.get("type")
+    if type_name not in _selectors:
+        raise SelectorNotFoundError(
+            f"No selector registered for type {type_name!r}. "
+            f"Available: {list(_selectors.keys())}"
+        )
+    return _selectors[type_name](spec)
+
+
+def register_allocator(strategy_name):
+    def decorator(cls):
+        _allocators[strategy_name] = cls
+        cls.strategy = strategy_name
+        return cls
+    return decorator
+
+
+def get_allocator(spec):
+    if not spec or not isinstance(spec, dict):
+        raise ValueError(f"Invalid allocation spec: {spec!r}")
+    strategy = spec.get("strategy")
+    if strategy not in _allocators:
+        raise AllocatorNotFoundError(
+            f"No allocator registered for strategy {strategy!r}. "
+            f"Available: {list(_allocators.keys())}"
+        )
+    return _allocators[strategy](spec)
+
+
+def registered_selectors():
+    return dict(_selectors)
+
+
+def registered_allocators():
+    return dict(_allocators)