From 9eeab32c8a2eba966d1ad8c1b9e54a86a3321222 Mon Sep 17 00:00:00 2001
From: Darell Tan <darell.tan@gmail.com>
Date: Sun, 24 Nov 2024 16:03:24 +0800
Subject: [PATCH] Added delayed-off for motion sensors

This ensures that the "motion detected" event doesn't flip flop, even if
the motion sensor itself was set to a low timeout like 10-30s. It stays
in the Detected state until no further detections occur within the
timeout period (hardcoded to 1 minute).
---
 s_motion_sensor.go | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/s_motion_sensor.go b/s_motion_sensor.go
index e028537..ea252e8 100644
--- a/s_motion_sensor.go
+++ b/s_motion_sensor.go
@@ -1,6 +1,9 @@
 package hapz2m
 
 import (
+	"sync"
+	"time"
+
 	"github.com/brutella/hap/accessory"
 	"github.com/brutella/hap/service"
 )
@@ -8,6 +11,35 @@ import (
 // there isn't a distinction between motion and occupancy sensors in z2m,
 // but most sensors are PIR, so they are technically motion sensors
 
+func setupDelayedOff(m *ExposeMapping, delay time.Duration) {
+	// lock makes sure Timer and setFunc aren't stepping over each other
+	lock := &sync.Mutex{}
+
+	tm := time.AfterFunc(1*time.Minute, func() {
+		lock.Lock()
+		defer lock.Unlock()
+
+		m.Characteristic.SetValueRequest( /*motion*/ false, nil)
+	})
+	tm.Stop()
+
+	m.SetCharacteristicValueFunc = func(m *ExposeMapping, newVal any, changed bool) (bool, error) {
+		lock.Lock()
+		defer lock.Unlock()
+
+		if newVal == true { // motion detected
+			tm.Stop()
+		} else { // hold off transitions to no motion
+			if changed {
+				tm.Reset(delay)
+			}
+			return false, nil
+		}
+
+		return true, nil
+	}
+}
+
 func createMotionServices(dev *Device) (byte, []*service.S, []*ExposeMapping, error) {
 	var svcs []*service.S
 	var exposes []*ExposeMapping
@@ -23,8 +55,11 @@ func createMotionServices(dev *Device) (byte, []*service.S, []*ExposeMapping, er
 
 			s := service.NewMotionSensor()
 
+			m := NewExposeMapping(&exp, s.MotionDetected.C)
+			setupDelayedOff(m, 1*time.Minute)
+
 			svcs = append(svcs, s.S)
-			exposes = append(exposes, NewExposeMapping(&exp, s.MotionDetected.C))
+			exposes = append(exposes, m)
 		}
 	}