Unmark devices as nearby when they stop sending advertisements

OpenHaystack/OpenHaystack/HaystackApp/AccessoryNearbyMonitor.swift

@@ -14,32 +14,66 @@ class AccessoryNearbyMonitor: BluetoothAccessoryDelegate {
     var accessoryController: AccessoryController
     var scanner: BluetoothAccessoryScanner
 
+    var cleanup: Timer?
+
     init(accessoryController: AccessoryController) {
         self.accessoryController = accessoryController
         self.scanner = BluetoothAccessoryScanner()
         self.initScanner()
+        self.initTimer()
     }
 
     func initScanner() {
         self.scanner.delegate = self
     }
 
+    func initTimer() {
+        self.cleanup = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { _ in
+            self.removeNearbyAccessories()
+        }
+    }
+
     func received(_ advertisement: Advertisement) {
         guard let accessory = getAccessoryForAdvertisement(advertisement) else {
             return
         }
+        updateNearbyAccessory(accessory)
+    }
+
+    func updateNearbyAccessory(_ accessory: Accessory) {
         if !accessory.isNearby {
             // Only set on state change
             accessory.isNearby = true
         }
+        accessory.lastAdvertisement = Date()
+    }
+
+    func removeNearbyAccessories(now: Date = Date(), timeout: TimeInterval = 10.0) {
+        let nearbyAccessories = self.accessoryController.accessories.filter({ $0.isNearby })
+        for accessory in nearbyAccessories {
+            guard let lastAdvertisement = accessory.lastAdvertisement else {
+                continue
+            }
+            if lastAdvertisement + timeout < now {
+                accessory.isNearby = false
+            }
+        }
     }
 
     func getAccessoryForAdvertisement(_ advertisement: Advertisement) -> Accessory? {
         let accessory =
-            try? self.accessoryController.accessories.first {
-                let accessoryPublicKey = try $0.getAdvertisementKey().advanced(by: 6)
-                return accessoryPublicKey == advertisement.publicKeyPayload
+            self.accessoryController.accessories.first {
+                isAdvertisement(advertisement, from: $0)
             } ?? nil
         return accessory
     }
+
+    func isAdvertisement(_ advertisement: Advertisement, from: Accessory) -> Bool {
+        do {
+            let accessoryPublicKey = try from.getAdvertisementKey().advanced(by: 6)
+            return accessoryPublicKey == advertisement.publicKeyPayload
+        } catch {
+            return false
+        }
+    }
 }

OpenHaystack/OpenHaystack/HaystackApp/Bluetooth/Advertisement.swift

@@ -18,7 +18,7 @@ struct Advertisement {
         guard let manufacturerData = fromAdvertisementData[CBAdvertisementDataManufacturerDataKey] as? Data else {
             return nil
         }
-        try? self.init(fromManufacturerData: manufacturerData)
+        self.init(fromManufacturerData: manufacturerData)
     }
 
     init?(fromManufacturerData: Data) {

OpenHaystack/OpenHaystack/HaystackApp/Model/Accessory.swift

@@ -53,6 +53,7 @@ class Accessory: ObservableObject, Codable, Identifiable, Equatable, Hashable {
             }
         }
     }
+    var lastAdvertisement: Date?
 
     init(name: String = "New accessory", color: Color = randomColor(), iconName: String = randomIcon()) throws {
         self.name = name