Enable reset saving

patlite_mqtt/daemon.py

@@ -1,10 +1,12 @@
 from __future__ import annotations
 
 import argparse
+import json
 import logging
 import os
 import signal
 import sys
+from pathlib import Path
 
 import paho.mqtt.client as mqtt
 from usb.core import USBError
@@ -13,6 +15,34 @@ from patlite_mqtt.channels import Mode, PatliteController
 from patlite_mqtt.device import PatliteDevice
 
 LOG = logging.getLogger("patlite_mqtt")
+STATE_FILE = Path.home() / ".local" / "state" / "patlite-mqtt" / "channels.json"
+
+
+def _load_state(controller: PatliteController) -> None:
+    if not STATE_FILE.is_file():
+        return
+    try:
+        data = json.loads(STATE_FILE.read_text(encoding="utf-8"))
+    except (OSError, json.JSONDecodeError):
+        LOG.warning("Could not read %s", STATE_FILE)
+        return
+    for name, value in data.items():
+        channel = controller.channels.get(name)
+        if channel is None:
+            continue
+        try:
+            channel.set_mode(Mode.parse(value))
+        except ValueError:
+            LOG.warning("Ignoring saved mode for %s: %r", name, value)
+
+
+def _save_state(controller: PatliteController) -> None:
+    data = {name: ch.mode.value for name, ch in controller.channels.items()}
+    try:
+        STATE_FILE.parent.mkdir(parents=True, exist_ok=True)
+        STATE_FILE.write_text(json.dumps(data) + "\n", encoding="utf-8")
+    except OSError as exc:
+        LOG.warning("Could not write %s: %s", STATE_FILE, exc)
 
 
 def parse_args(argv: list[str] | None = None) -> argparse.Namespace:
@@ -111,6 +141,7 @@ class PatliteMqttDaemon:
 
         LOG.info("%s -> %s", message.topic, mode.value)
         channel.set_mode(mode)
+        _save_state(self._controller)
 
     def run(self):
         self._client.connect(
@@ -150,6 +181,7 @@ def main(argv: list[str] | None = None) -> int:
         fast_delay=args.fast_delay,
         slow_delay=args.slow_delay,
     )
+    _load_state(controller)
     daemon = PatliteMqttDaemon(args, controller)
 
     def handle_signal(signum, frame):