From e417faa43142a2caf57aa4b137567a4740754cfe Mon Sep 17 00:00:00 2001
From: Kenny Levinsen <kl@kl.wtf>
Date: Sat, 14 Dec 2024 22:32:18 +0100
Subject: [PATCH] danfoss: Update time regularly to account for loss and drift

Danfoss eTRVs will regularly lose their time, such as on battery change,
after updates, after hardware resets, etc., which leads to wildly
inaccurate date and time of day. Even without these events, clock drift
may lead to slowly growing clock errors.

This not only breaks scheduling, but also causes the automatic adaption
runs which cut off heating to run at inappropriate times such as in the
middle of the day when heat is required.

Follow the Danfoss recommendations and set time when the device
connects, and at a one week interval.
---
 src/devices/danfoss.ts | 36 +++++++++++++++++++++++++++++++-----
 1 file changed, 31 insertions(+), 5 deletions(-)

diff --git a/src/devices/danfoss.ts b/src/devices/danfoss.ts
index 81274b0d67b0e..c69bd19961d6d 100644
--- a/src/devices/danfoss.ts
+++ b/src/devices/danfoss.ts
@@ -5,11 +5,20 @@ import tz from '../converters/toZigbee';
 import * as constants from '../lib/constants';
 import * as exposes from '../lib/exposes';
 import * as reporting from '../lib/reporting';
-import {DefinitionWithExtend} from '../lib/types';
+import * as globalStore from '../lib/store';
+import {DefinitionWithExtend, Zh} from '../lib/types';
 
 const e = exposes.presets;
 const ea = exposes.access;
 
+const setTime = async (device: Zh.Device) => {
+    const endpoint = device.getEndpoint(1);
+    const time = Math.round((new Date().getTime() - constants.OneJanuary2000) / 1000);
+    // Time-master + synchronised
+    const values = {timeStatus: 1, time: time, timeZone: new Date().getTimezoneOffset() * -1 * 60};
+    await endpoint.write('genTime', values);
+};
+
 const definitions: DefinitionWithExtend[] = [
     {
         // eTRV0100 is the same as Hive TRV001 and Popp eT093WRO. If implementing anything, please consider
@@ -334,10 +343,27 @@ const definitions: DefinitionWithExtend[] = [
 
             // Seems that it is bug in Danfoss, device does not asks for the time with binding
             // So, we need to write time during configure (same as for HEIMAN devices)
-            const time = Math.round((new Date().getTime() - constants.OneJanuary2000) / 1000);
-            // Time-master + synchronised
-            const values = {timeStatus: 1, time: time, timeZone: new Date().getTimezoneOffset() * -1 * 60};
-            await endpoint.write('genTime', values);
+            await setTime(device);
+        },
+        onEvent: async (type, data, device) => {
+            if (type === 'stop') {
+                clearInterval(globalStore.getValue(device, 'interval'));
+                globalStore.clearValue(device, 'interval');
+            } else if (['deviceAnnounce', 'start'].includes(type)) {
+                // The device might have lost its time, so reset it. It would be more proper to check if
+                // the danfossSystemStatusCode has bit 10 of the SW error code attribute (0x4000) in the
+                // diagnostics cluster (0x0b05) is set to indicate time lost, but setting it once too many
+                // times shouldn't hurt.
+                await setTime(device);
+
+                if (!globalStore.hasValue(device, 'interval')) {
+                    // Set up a timer to refresh the time once a week to mitigate timer drift, as described
+                    // in the Danfoss documentation. Be careful to not bump this timer past the signed 32-bit
+                    // integer limit of setInterval, which is roughly 24.8 days.
+                    const interval = setInterval(async () => await setTime(device), 10080000);
+                    globalStore.putValue(device, 'interval', interval);
+                }
+            }
         },
     },
     {