From b9f2eea89bb00bc7cd809369ec5cfe8434501511 Mon Sep 17 00:00:00 2001
From: Alessandro De Maria <ademaria@isomorphiclabs.com>
Date: Sat, 30 Nov 2024 22:10:08 +0000
Subject: [PATCH] allows dynamic import

---
 kapitan/inputs/__init__.py | 47 +++++++++++++++++++-------------------
 1 file changed, 24 insertions(+), 23 deletions(-)

diff --git a/kapitan/inputs/__init__.py b/kapitan/inputs/__init__.py
index 956e9d232..b7f49cab3 100644
--- a/kapitan/inputs/__init__.py
+++ b/kapitan/inputs/__init__.py
@@ -2,34 +2,35 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
+import functools  # Import functools for caching
+import importlib
 from typing import Type
 
 from kapitan.inventory.model.input_types import InputTypes
 
 from .base import InputType
-from .copy import Copy
-from .external import External
-from .helm import Helm
-from .jinja2 import Jinja2
-from .jsonnet import Jsonnet
-from .kadet import Kadet
-from .remove import Remove
-
-# Dict mapping values for command line flag `--inventory-backend` to the
-# associated `Inventory` subclass.
-AVAILABLE_INPUT_TYPES: dict[str, Type[InputType]] = {
-    InputTypes.JINJA2: Jinja2,
-    InputTypes.HELM: Helm,
-    InputTypes.JSONNET: Jsonnet,
-    InputTypes.KADET: Kadet,
-    InputTypes.COPY: Copy,
-    InputTypes.EXTERNAL: External,
-    InputTypes.REMOVE: Remove,
-}
 
 
+@functools.lru_cache(maxsize=None)  # Use lru_cache for caching
 def get_compiler(input_type: InputType) -> Type[InputType]:
-    """
-    Get the `Inventory` subclass associated with the given `backend_name`.
-    """
-    return AVAILABLE_INPUT_TYPES.get(input_type)
+    """Dynamically imports and returns the compiler class based on input_type."""
+
+    module_map = {
+        InputTypes.JINJA2: "jinja2",
+        InputTypes.HELM: "helm",
+        InputTypes.JSONNET: "jsonnet",
+        InputTypes.KADET: "kadet",
+        InputTypes.COPY: "copy",
+        InputTypes.EXTERNAL: "external",
+        InputTypes.REMOVE: "remove",
+    }
+
+    module_name = module_map.get(input_type)
+    if module_name:
+        try:
+            module = importlib.import_module(f".{module_name}", package=__name__)
+            return getattr(module, module_name.capitalize())  # Capitalize to get class name
+        except (ImportError, AttributeError) as e:
+            raise ImportError(f"Could not import module or class for {input_type}: {e}") from e
+    else:
+        return None  # Or raise an appropriate error for unknown input_type