From ed92d590a8703ef087531b2776d9446735c4c462 Mon Sep 17 00:00:00 2001
From: Stanislaw Malinowski <stanislaw.malinowski@diamond.ac.uk>
Date: Tue, 25 Jun 2024 19:01:45 +0100
Subject: [PATCH] a new factory

---
 src/dodal/beamlines/example_beamline.py      | 98 ++++++++++++++++++++
 src/dodal/beamlines/i22.py                   | 10 +-
 src/dodal/common/beamlines/beamline_utils.py |  4 +-
 3 files changed, 102 insertions(+), 10 deletions(-)
 create mode 100644 src/dodal/beamlines/example_beamline.py

diff --git a/src/dodal/beamlines/example_beamline.py b/src/dodal/beamlines/example_beamline.py
new file mode 100644
index 0000000000..3cbc192b29
--- /dev/null
+++ b/src/dodal/beamlines/example_beamline.py
@@ -0,0 +1,98 @@
+from dataclasses import dataclass
+from functools import _Wrapped, wraps
+from typing import Callable, Dict, Optional, TypeVar
+
+from bluesky.run_engine import call_in_bluesky_event_loop
+from ophyd_async.core import Device as OphydV2Device
+
+from dodal.common.beamlines.beamline_utils import (
+    ACTIVE_DEVICES,
+    DEFAULT_CONNECTION_TIMEOUT,
+)
+
+
+class XYZDetector:
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+    @property
+    def hints(self):
+        raise NotImplementedError
+
+
+T = TypeVar("T", bound=OphydV2Device)
+
+LAZY_DEVICES: Dict[str, OphydV2Device] = {}
+
+
+@dataclass
+class DeviceInitalizationConfig:
+    name: str
+    prefix: str
+    lazy: bool = False
+    fake: bool = False
+    timeout: float = DEFAULT_CONNECTION_TIMEOUT
+    bl_prefix: bool = True
+
+
+class DeviceInitalizationController:
+    device: Optional[OphydV2Device] = None
+    config: Optional[DeviceInitalizationConfig] = None
+
+    def __init__(self, config: DeviceInitalizationConfig) -> None:
+        self.config = config
+        super().__init__()
+
+    # TODO right now the cache is in a global variable ACTIVE_DEVICES, that should change
+    def see_if_device_is_in_cache(self, name: str) -> Optional[OphydV2Device]:
+        d = ACTIVE_DEVICES.get(name)
+        assert d is OphydV2Device
+        # todo temporarily throw an error if the device is from v1
+        return d
+
+    # todo splitting the logic for initalizing the device and the logic for caching the device
+    # potentially more features too
+    def initalize_device(
+        self,
+        factory: Callable[[], T],
+        post_create: Optional[Callable[[T], None]] = None,
+    ) -> T:
+        assert self.config is not None
+        # todo add fake and cache logic
+        device = factory()
+        if self.config.lazy:
+            print(f"Device {factory.__name__} is lazy, not initalizing now")
+            LAZY_DEVICES[self.config.name] = device
+        else:
+            call_in_bluesky_event_loop(device.connect(timeout=self.config.timeout))
+        if self.config.fake:
+            print("Running in fake mode")
+        if post_create:
+            post_create(device)
+        return device
+
+
+def instance_behavior(
+    config: DeviceInitalizationConfig,
+    post_create: Optional[Callable[[T], None]] = None,
+) -> Callable[[Callable[[], T]], _Wrapped]:
+    def decorator(device_specific_subclass):
+        controller = DeviceInitalizationController(config=config)
+
+        @wraps(device_specific_subclass)
+        def wrapper(*args, **kwargs) -> OphydV2Device:
+            return controller.initalize_device(device_specific_subclass, post_create)
+
+        return wrapper
+
+    return decorator
+
+
+@instance_behavior(
+    config=DeviceInitalizationConfig(
+        name="det1", prefix="xyz:", lazy=True, fake=True, timeout=10
+    ),
+    post_create=None,
+)
+def detector_xyz() -> XYZDetector:
+    return XYZDetector()
diff --git a/src/dodal/beamlines/i22.py b/src/dodal/beamlines/i22.py
index ba079d163c..a3e2c51a8e 100644
--- a/src/dodal/beamlines/i22.py
+++ b/src/dodal/beamlines/i22.py
@@ -4,8 +4,8 @@
 from ophyd_async.panda import HDFPanda
 
 from dodal.common.beamlines.beamline_utils import (
+    decorator_name,
     device_factory,
-    device_factory3,
     device_instantiation,
     get_directory_provider,
     set_directory_provider,
@@ -376,11 +376,3 @@ def linkam(
         fake_with_ophyd_sim,
     )
 
-
-@device_factory3(lazy=True, fake=True, post_create=None, timeout=10)
-def test_device():
-    return AravisDetector(
-        prefix="TEST:",
-        name="test_device",
-        directory_provider=get_directory_provider(),
-    )
diff --git a/src/dodal/common/beamlines/beamline_utils.py b/src/dodal/common/beamlines/beamline_utils.py
index a011c9ac68..ccefe4e3be 100644
--- a/src/dodal/common/beamlines/beamline_utils.py
+++ b/src/dodal/common/beamlines/beamline_utils.py
@@ -220,7 +220,7 @@ def get_directory_provider() -> UpdatingDirectoryProvider:
 
 
 @skip_device()
-def device_factory3(
+def decorator_name(
     name: str,
     prefix: str,
     not_lazy: bool,
@@ -275,3 +275,5 @@ def device_factory3(
     if post_create:
         post_create(device_instance)
     return device_instance
+
+