import Foundation
import CoreBluetooth

struct Peripheral: Identifiable {
    let id: Int
    let name: String
    let rssi: Int
}

class BLEManager: NSObject, ObservableObject, CBCentralManagerDelegate {

    var myCentral: CBCentralManager!

    @Published var serviceUUID = CBUUID(string: "----redacted for privacy----")
    @Published var characteristicUUID = CBUUID(string: "----redacted for privacy----")

    @Published var isSwitchedOn = false
    @Published var peripherals = [CBPeripheral]()
    @Published var isScanning = false
    @Published var settingCharacteristic: CBCharacteristic?

    var recievedData = Data()

    @Published var settingData: NetworkSettings? {
        willSet{
            objectWillChange.send()
        }
    }


    override init() {
        super.init()

        myCentral = CBCentralManager(delegate: self, queue: nil)
        myCentral.delegate = self
        isScanning = myCentral.isScanning
    }

    // Ran if state of CBCM updates
    func centralManagerDidUpdateState(_ central: CBCentralManager) {
        if central.state == .poweredOn {
            isSwitchedOn = true
        }
        else {
            isSwitchedOn = false
        }
    }


    // Ran if devices discovered
    func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {

        //print(advertisementData)

        if(peripherals.contains(where: {peri in peri == peripheral})){
            let index = peripherals.firstIndex(where: {peri in peri == peripheral})
            peripherals[index!] = peripheral
        }else{
            peripherals.append(peripheral)
        }

    }

    func startScanning() {
        print("startScanning")
        myCentral.scanForPeripherals(withServices: [serviceUUID], options: [CBCentralManagerScanOptionAllowDuplicatesKey: true, CBCentralManagerScanOptionSolicitedServiceUUIDsKey: [serviceUUID]])
        isScanning = myCentral.isScanning
    }

    func stopScanning() {
        print("stopScanning")
        myCentral.stopScan()
        isScanning = myCentral.isScanning
    }

    // Connect to device after connected
    func connect(peripheral: CBPeripheral){
        myCentral.connect(peripheral, options: nil)
    }

    func centralManager(_ central: CBCentralManager, didFailToConnect peripheral: CBPeripheral, error: Error?) {
        print("Failed to connect to pi.")
    }
}

extension BLEManager: CBPeripheralDelegate{

    // .... here is some BLE stuff - not needed for error info

    // Got setting data
    func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {
        // Deal with errors (if any)
        if let error = error {
            print("Error discovering characteristics: " + error.localizedDescription)
            return
        }

        guard let characteristicData = characteristic.value else {return}

        print("Received bytes: \(characteristicData.count)")
        print(String(decoding: characteristicData, as: UTF8.self))

        // HERE has to happen the magic: The value is updated from nil to a NetworkSettings struct / instance - but nothing re-renders in SwiftUI!
        self.settingData = getNetworkSettingsFromString(data: String(decoding: characteristicData, as: UTF8.self))
        // Already treid using this - no change
        // objectWillChange.send()

    }
}