From deb6b2bdcc9c8232fc39491e223191a5ab02a25a Mon Sep 17 00:00:00 2001
From: Timothy Allen <tim@treehouse.org.za>
Date: Sat, 2 May 2026 18:13:33 +0200
Subject: [PATCH] Add a new DeviceState class to capture metadata from a
 reading

---
 bmspy/server.py | 33 +++++++++++++++++++--------------
 1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/bmspy/server.py b/bmspy/server.py
index ca6acb1..127e39c 100755
--- a/bmspy/server.py
+++ b/bmspy/server.py
@@ -11,12 +11,21 @@ import atexit
 import signal
 import json
 import struct
-from dataclasses import asdict as dataclass_asdict
+import serial
+from dataclasses import asdict as dataclass_asdict, dataclass
 from typing import Any, NoReturn
 
 from bmspy.utilities import debugger
+from bmspy.classes import UPS
 from bmspy.jbd_bms import collect_data, initialise_serial
 
+
+@dataclass
+class DeviceState:
+    ser: serial.Serial
+    data: UPS | None = None
+    timestamp: float = 0.0
+
 # Expected kernel log output when the USB-serial adapter is plugged in:
 # usb 1-1.4: new full-speed USB device number 4 using xhci_hcd
 # usb 1-1.4: New USB device found, idVendor=0403, idProduct=6001, bcdDevice= 6.00
@@ -161,17 +170,13 @@ def main():
     debug = args.verbose
 
     device_list = args.devices or ["/dev/ttyUSB0"]
-    ups_devices = {}
+    ups_devices: dict[str, DeviceState] = {}
     for device_str in device_list:
         name, path = parse_device(device_str)
         if name in ups_devices:
             debugger("server: duplicate UPS name '{}', skipping {}".format(name, path))
             continue
-        ups_devices[name] = {
-            "ser": initialise_serial(path, debug),
-            "data": None,
-            "timestamp": 0,
-        }
+        ups_devices[name] = DeviceState(ser=initialise_serial(path, debug))
         if debug > 0:
             print("server: registered UPS '{}' on {}".format(name, path))
 
@@ -297,17 +302,17 @@ def main():
                         if debug > 0:
                             debugger(
                                 "reading data for '{}', timestamp={}, time={}".format(
-                                    name, device["timestamp"], time.time()
+                                    name, device.timestamp, time.time()
                                 )
                             )
                         # only get new data five seconds after the last read
-                        if device["timestamp"] <= time.time() - 5:
-                            device["data"] = None
-                            while not device["data"]:
-                                device["data"] = collect_data(device["ser"], debug)
+                        if device.timestamp <= time.time() - 5:
+                            device.data = None
+                            while not device.data:
+                                device.data = collect_data(device.ser, debug)
                                 time.sleep(1)
-                            device["timestamp"] = time.time()
-                        result[name] = device["data"]
+                            device.timestamp = time.time()
+                        result[name] = device.data
 
                     send_response(connection, result, client, debug)