From f7355270c8b2ce6ef18d493d4b74e65ace47b5dd Mon Sep 17 00:00:00 2001
From: Jens Ahrensfeld <jens@jayfield.org>
Date: Thu, 25 Jun 2026 20:44:43 +0200
Subject: [PATCH] Extract shared factory dispatch into ComponentFactory base
 class

All four name-dispatch factories repeated the same if/elif lazy-import
pattern. Replace with a ComponentFactory base class holding a callable
registry and a _lazy() helper for the common import-and-construct case.
PlantFactory is an orchestrator, not a dispatcher, and is left as-is.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Tqxrk8uj4M3w3d3eXm3xK8
---
 components/actor/heaterFactory.py       | 15 ++++++---------
 components/actor/stirrerFactory.py      | 20 +++++++++++---------
 components/factory.py                   | 19 +++++++++++++++++++
 components/pid/pid_factory.py           | 15 ++++++---------
 components/sensor/tempsensor_factory.py | 15 ++++++---------
 5 files changed, 48 insertions(+), 36 deletions(-)
 create mode 100644 components/factory.py

diff --git a/components/actor/heaterFactory.py b/components/actor/heaterFactory.py
index cbaa4b8..59d0521 100644
--- a/components/actor/heaterFactory.py
+++ b/components/actor/heaterFactory.py
@@ -1,11 +1,8 @@
+from components.factory import ComponentFactory, _lazy
 
 
-class HeaterFactory:
-	@staticmethod
-	def create(name, *args, **kwargs):
-		if "sim" in name:
-			from components.actor.heater_sim import HeaterSim
-			return HeaterSim(*args, **kwargs)
-		elif "Hendi" in name:
-			from components.actor.heater_hendi import HeaterHendi
-			return HeaterHendi(*args, **kwargs)
+class HeaterFactory(ComponentFactory):
+    _registry = {
+        "sim":   _lazy("components.actor.heater_sim", "HeaterSim"),
+        "Hendi": _lazy("components.actor.heater_hendi", "HeaterHendi"),
+    }
diff --git a/components/actor/stirrerFactory.py b/components/actor/stirrerFactory.py
index ecc9818..1aaad7a 100644
--- a/components/actor/stirrerFactory.py
+++ b/components/actor/stirrerFactory.py
@@ -1,11 +1,13 @@
+from components.factory import ComponentFactory, _lazy
 
 
-class StirrerFactory:
-	@staticmethod
-	def create(name, dt, params):
-		if "sim" in name:
-			from components.actor.stirrersim import StirrerSim
-			return StirrerSim(dt)
-		elif "1376" in name:
-			from components.actor.stirrerpololu1376 import StirrerPololu1376
-			return StirrerPololu1376(dt, params)
+def _sim(dt, params):
+    from components.actor.stirrersim import StirrerSim
+    return StirrerSim(dt)
+
+
+class StirrerFactory(ComponentFactory):
+    _registry = {
+        "sim":  _sim,
+        "1376": _lazy("components.actor.stirrerpololu1376", "StirrerPololu1376"),
+    }
diff --git a/components/factory.py b/components/factory.py
new file mode 100644
index 0000000..e80d6be
--- /dev/null
+++ b/components/factory.py
@@ -0,0 +1,19 @@
+import importlib
+
+
+def _lazy(module, classname):
+    """Return a builder that lazily imports module.classname on first call."""
+    def build(*args, **kwargs):
+        return getattr(importlib.import_module(module), classname)(*args, **kwargs)
+    return build
+
+
+class ComponentFactory:
+    _registry = {}
+
+    @classmethod
+    def create(cls, name, *args, **kwargs):
+        for key, builder in cls._registry.items():
+            if key in name:
+                return builder(*args, **kwargs)
+        raise ValueError(f"{cls.__name__}: unknown name {name!r}")
diff --git a/components/pid/pid_factory.py b/components/pid/pid_factory.py
index d49ef6f..43963db 100644
--- a/components/pid/pid_factory.py
+++ b/components/pid/pid_factory.py
@@ -1,11 +1,8 @@
+from components.factory import ComponentFactory, _lazy
 
 
-class PidFactory:
-	@staticmethod
-	def create(name, *args, **kwargs):
-		if "Normal" in name:
-			from components.pid.temp_controller import TempController
-			return TempController(*args, **kwargs)
-		elif "Smith" in name:
-			from components.pid.temp_controller_smith import TempController
-			return TempController(*args, **kwargs)
+class PidFactory(ComponentFactory):
+    _registry = {
+        "Normal": _lazy("components.pid.temp_controller", "TempController"),
+        "Smith":  _lazy("components.pid.temp_controller_smith", "TempController"),
+    }
diff --git a/components/sensor/tempsensor_factory.py b/components/sensor/tempsensor_factory.py
index dc7aa71..af065fb 100644
--- a/components/sensor/tempsensor_factory.py
+++ b/components/sensor/tempsensor_factory.py
@@ -1,11 +1,8 @@
+from components.factory import ComponentFactory, _lazy
 
 
-class TempSensorFactory:
-	@staticmethod
-	def create(name, *args, **kwargs):
-		if "sim" in name:
-			from components.sensor.tempSensorSim import TempSensorSim
-			return TempSensorSim(*args, **kwargs)
-		elif "31865" in name:
-			from components.sensor.tempSensor_max31865 import TempSensor_max31865
-			return TempSensor_max31865(*args, **kwargs)
+class TempSensorFactory(ComponentFactory):
+    _registry = {
+        "sim":   _lazy("components.sensor.tempSensorSim", "TempSensorSim"),
+        "31865": _lazy("components.sensor.tempSensor_max31865", "TempSensor_max31865"),
+    }