feat: Writes to characteristic

Sources/scoobytag/BluetoothManager.swift

@@ -1,8 +1,14 @@
 import SwiftUI
 import CoreBluetooth
 
+struct Constants {
+    static let scbtSvcUuid = "00010F2C-DEAD-BEEF-A455-DEAD69BEEF69";
+    static let scbtPetUuid: String = "00010F2D-DEAD-BEEF-A455-DEAD69BEEF69";
+}
+
 final class BluetoothManager: NSObject, ObservableObject {
-    private var periphManager: CBPeripheralManager!
+    private var centralManager: CBCentralManager!
+    private var myPeripheral: CBPeripheral?
 	@Published var status = "Starting..."
 
     override init() {
@@ -11,22 +17,135 @@ final class BluetoothManager: NSObject, ObservableObject {
     }
 }
 
-extension BluetoothManager: CBPeripheralManagerDelegate {
-    func peripheralManagerDidUpdateState(_ central: CBPeripheralManager) {
-        switch central.state {
-        case .poweredOn:
-            status = "Broadcasting"
-            let uuid = CBUUID(string: "12345678-1234-1234-1234-123456789ABC")
-            periphManager.startAdvertising(
-                [
-                    CBAdvertisementDataServiceUUIDsKey: [uuid],
-                    CBAdvertisementDataLocalNameKey: "scbt-Test"
-                ])
-        case .poweredOff:
-            status = "Bluetooth off"
+extension BluetoothManager: CBCentralManagerDelegate, CBPeripheralDelegate {
+    func centralManagerDidUpdateState(_ central: CBCentralManager) {
+        guard central.state == .poweredOn else {
+            status = "Bluetooth OFF"
+            return
+        }
 
-        default:
-            status = "Bluetooth unavailable"
+        let uuid = CBUUID(string: Constants.scbtSvcUuid)
+        centralManager.scanForPeripherals(
+            withServices: [uuid],
+            options: [
+                CBCentralManagerScanOptionAllowDuplicatesKey: false
+            ]
+        )
+    }
+
+    // Discovery callback
+    func centralManager(
+        _ central: CBCentralManager,
+        didDiscover peripheral: CBPeripheral,
+        advertisementData: [String: Any],
+        rssi RSSI: NSNumber
+    ) {
+        if (peripheral.name != nil) {
+            status = "Found: \(peripheral.name!)"
+        } else {
+            status = "Found: \(peripheral.identifier)"
+        }
+
+        myPeripheral = peripheral
+        central.stopScan()
+        central.connect(peripheral)
+    }
+
+    // Connection callback
+    func centralManager(
+        _ central: CBCentralManager,
+        didConnect peripheral: CBPeripheral
+    ) {
+        status = "Connected"
+        let uuid = CBUUID(string: Constants.scbtSvcUuid)
+        peripheral.discoverServices([uuid])
+        peripheral.delegate = self
+    }
+
+    // Connection failure callback
+    func centralManager(
+        _ central: CBCentralManager,
+        didFailToConnect peripheral: CBPeripheral,
+        error: Error?
+    ) {
+        let error2: String
+        if (error == nil) { error2 = "unknown" }
+        else { error2 = "\(error!)" }
+        status = "Failed: \(error2)"
+    }
+
+    // Disconnection callback
+    func centralManager(
+        _ central: CBCentralManager,
+        didDisconnectPeripheral peripheral: CBPeripheral,
+        error: Error?
+    ) {
+        let error2: String
+        if (error == nil) { error2 = "unknown" }
+        else { error2 = "\(error!)" }
+        status = "Disconnected: \(error2)"
+    }
+
+    // Service callback
+    func peripheral(
+        _ peripheral: CBPeripheral,
+        didDiscoverServices error: Error?
+    ) {
+        guard let services = peripheral.services else { return }
+
+        status = "Service found"
+
+        let scbtSvc = CBUUID(string: Constants.scbtSvcUuid)
+        let scbtPet = CBUUID(string: Constants.scbtPetUuid)
+
+        for service in services {
+            // Ignore non scbtSvc
+            if (service.uuid != scbtSvc) { continue }
+
+            peripheral.discoverCharacteristics([scbtPet], for: service)
+        }
+    }
+
+    // Characteristic callback
+    func peripheral(
+        _ perihperal: CBPeripheral,
+        didDiscoverCharacteristicsFor service: CBService,
+        error: Error?
+    ) {
+        if (error != nil) {
+            status = "\(error!)"
+            return
+        }
+
+        guard let characteristics = service.characteristics else { return }
+
+        status = "Characteristics found (\(characteristics.count))"
+
+        let scbtPet = CBUUID(string: Constants.scbtPetUuid)
+
+        for characteristic in characteristics {
+            // Ignore non pet
+            if (characteristic.uuid != scbtPet) { continue }
+
+            var value: UInt32 = 0
+            let data = Data(bytes: &value, count: MemoryLayout<UInt32>.size)
+
+            perihperal.writeValue(data, for: characteristic, type: .withResponse)
+            status = "Written \(data)"
+        }
+    }
+
+    // Characteristic write callback
+    func peripheral(
+        _ perihperal: CBPeripheral,
+        didWriteValueFor characteristic: CBCharacteristic,
+        error: (any Error)?
+    ) {
+        if (error == nil) {
+            status = "Write success"
+        }
+        else {
+            status = "Write failed: \(error!)"
         }
     }
 }