iOS/Sources/Shared/API/Webhook/Sensors/ConnectivitySensor.swift

import Foundation
import PromiseKit
#if os(iOS)
import CoreTelephony
import Reachability
#endif

final class ConnectivitySensorUpdateSignaler: SensorProviderUpdateSignaler, SensorObserver {
    private var isObserving = false
    let signal: () -> Void

    #if DEBUG
    /// Used for unit test to identify when observation is ready
    var notifyObservation: (() -> Void)?
    #endif

    init(signal: @escaping () -> Void) {
        self.signal = signal
        Current.sensors.register(observer: self)
    }

    @objc private func connectivityDidChange(_ note: Notification) {
        signal()
    }

    private func observe() {
        guard !isObserving else { return }
        NotificationCenter.default.addObserver(
            self,
            selector: #selector(connectivityDidChange(_:)),
            name: Current.connectivity.connectivityDidChangeNotification(),
            object: nil
        )
        isObserving = true

        #if DEBUG
        notifyObservation?()
        #endif
    }

    private func stopObserving() {
        guard isObserving else { return }
        NotificationCenter.default.removeObserver(
            self,
            name: Current.connectivity.connectivityDidChangeNotification(),
            object: nil
        )
        isObserving = false
    }

    func sensorContainer(_ container: SensorContainer, didUpdate update: SensorObserverUpdate) {
        update.sensors.done { [weak self] sensors in
            let activeRelatedSensors = sensors.filter({ sensor in
                sensor.UniqueID == WebhookSensorId.connectivitySSID.rawValue ||
                    sensor.UniqueID == WebhookSensorId.connectivityBSID.rawValue ||
                    sensor.UniqueID == WebhookSensorId.connectivityConnectionType.rawValue
            })

            let activeSensors = activeRelatedSensors.filter({ sensor in
                Current.sensors.isEnabled(sensor: sensor)
            })

            if activeSensors.isEmpty {
                self?.stopObserving()
            } else {
                self?.observe()
            }
        }
    }

    func sensorContainer(
        _ container: SensorContainer,
        didSignalForUpdateBecause reason: SensorContainerUpdateReason,
        lastUpdate: SensorObserverUpdate?
    ) {
        /* no-op */
    }
}

public class ConnectivitySensor: SensorProvider {
    public enum ConnectivityError: Error {
        case unsupportedPlatform
        case noCarriers
    }

    public let request: SensorProviderRequest
    public required init(request: SensorProviderRequest) {
        self.request = request
    }

    public func sensors() -> Promise<[WebhookSensor]> {
        #if os(iOS)
        let sensors: Promise<[WebhookSensor]> = firstly { () -> Guarantee<[Result<[WebhookSensor]>]> in
            var sensors = [Promise<[WebhookSensor]>]()

            sensors.append(ssid())
            sensors.append(connectionType())
            #if !targetEnvironment(macCatalyst)
            sensors.append(cellularProviders())
            #endif

            return when(resolved: sensors)
        }.map { sensors -> [WebhookSensor] in
            sensors.compactMap { (result: Result<[WebhookSensor]>) -> [WebhookSensor]? in
                if case let .fulfilled(value) = result {
                    return value
                } else {
                    return nil
                }
            }.flatMap { $0 }
        }

        // Set up our observer
        let _: ConnectivitySensorUpdateSignaler = request.dependencies.updateSignaler(for: self)

        return sensors
        #else
        return .init(error: ConnectivityError.unsupportedPlatform)
        #endif
    }

    #if os(iOS)

    private func ssid() -> Promise<[WebhookSensor]> {
        guard Current.connectivity.hasWiFi() else {
            return .init(error: ConnectivityError.unsupportedPlatform)
        }

        return .value([
            with(WebhookSensor(name: "SSID", uniqueID: WebhookSensorId.connectivitySSID.rawValue)) { sensor in
                if let ssid = Current.connectivity.currentWiFiSSID() {
                    sensor.State = ssid
                    sensor.Icon = "mdi:wifi"
                } else {
                    sensor.State = "Not Connected"
                    sensor.Icon = "mdi:wifi-off"
                }
            },
            with(WebhookSensor(name: "BSSID", uniqueID: WebhookSensorId.connectivityBSID.rawValue)) { sensor in
                if let bssid = Current.connectivity.currentWiFiBSSID() {
                    sensor.State = bssid
                    sensor.Icon = "mdi:wifi-star"
                } else {
                    sensor.State = "Not Connected"
                    sensor.Icon = "mdi:wifi-off"
                }
            },
        ])
    }

    #endif

    #if os(iOS)

    private func connectionType() -> Promise<[WebhookSensor]> {
        let simple = Current.connectivity.simpleNetworkType()

        return .value([
            with(WebhookSensor(
                name: "Connection Type",
                uniqueID: WebhookSensorId.connectivityConnectionType.rawValue
            )) { sensor in
                sensor.State = simple.description
                sensor.Icon = simple.icon

                var attributes = Current.connectivity.networkAttributes()

                if case .cellular = simple {
                    let cellular = Current.connectivity.cellularNetworkType()
                    attributes["Cellular Technology"] = cellular.description
                }

                sensor.Attributes = attributes
            },
        ])
    }

    #if !targetEnvironment(macCatalyst)
    private func cellularProviders() -> Promise<[WebhookSensor]> {
        let networkInfo = Current.connectivity.telephonyCarriers()
        let radioTech = Current.connectivity.telephonyRadioAccessTechnology()

        if let networkInfo {
            return when(fulfilled: networkInfo.map {
                carrierSensor(
                    carrier: $0.value,
                    radioTech: radioTech?[$0.key],
                    key: $0.key
                )
            })
        } else {
            return .init(error: ConnectivityError.noCarriers)
        }
    }

    private func carrierSensor(
        carrier: CTCarrier,
        radioTech: String?,
        key: String
    ) -> Guarantee<WebhookSensor> {
        let sensor: WebhookSensor

        let id = key.last ?? "?"
        sensor = WebhookSensor(
            name: "SIM \(id)",
            uniqueID: "connectivity_sim_\(id)",
            icon: "mdi:sim",
            state: "Unknown"
        )

        sensor.State = carrier.carrierName ?? "N/A"
        sensor.Attributes = [
            "Carrier ID": key,
            "Carrier Name": carrier.carrierName ?? "N/A",
            "Mobile Country Code": carrier.mobileCountryCode ?? "N/A",
            "Mobile Network Code": carrier.mobileNetworkCode ?? "N/A",
            "ISO Country Code": carrier.isoCountryCode ?? "N/A",
            "Allows VoIP": carrier.allowsVOIP,
        ]

        if let radioTech {
            sensor.Attributes?["Current Radio Technology"] = Self.getRadioTechName(radioTech)
        }

        return .value(sensor)
    }

    private static func getRadioTechName(_ radioTech: String) -> String? {
        switch radioTech {
        case CTRadioAccessTechnologyGPRS:
            return "General Packet Radio Service (GPRS)"
        case CTRadioAccessTechnologyEdge:
            return "Enhanced Data rates for GSM Evolution (EDGE)"
        case CTRadioAccessTechnologyCDMA1x:
            return "Code Division Multiple Access (CDMA 1X)"
        case CTRadioAccessTechnologyWCDMA:
            return "Wideband Code Division Multiple Access (WCDMA)"
        case CTRadioAccessTechnologyHSDPA:
            return "High Speed Downlink Packet Access (HSDPA)"
        case CTRadioAccessTechnologyHSUPA:
            return "High Speed Uplink Packet Access (HSUPA)"
        case CTRadioAccessTechnologyCDMAEVDORev0:
            return "Code Division Multiple Access Evolution-Data Optimized Revision 0 (CDMA EV-DO Rev. 0)"
        case CTRadioAccessTechnologyCDMAEVDORevA:
            return "Code Division Multiple Access Evolution-Data Optimized Revision A (CDMA EV-DO Rev. A)"
        case CTRadioAccessTechnologyCDMAEVDORevB:
            return "Code Division Multiple Access Evolution-Data Optimized Revision B (CDMA EV-DO Rev. B)"
        case CTRadioAccessTechnologyeHRPD:
            return "High Rate Packet Data (HRPD)"
        case CTRadioAccessTechnologyLTE:
            return "Long-Term Evolution (LTE)"
        default:
            switch radioTech {
            case CTRadioAccessTechnologyNR:
                return "5G"
            case CTRadioAccessTechnologyNRNSA:
                return "5G Non-Standalone"
            default: return nil
            }
        }
    }
    #endif
    #endif
}