import Algorithms
import Combine
import Foundation
import LoopKit
import LoopKitUI
import MinimedKit
import MockKit
import OmniBLE
import OmniKit
import ShareClient
import SwiftDate
import Swinject
import UserNotifications

protocol DeviceDataManager: GlucoseSource {
    var pumpManager: PumpManagerUI? { get set }
    var bluetoothManager: BluetoothStateManager { get }
    var loopInProgress: Bool { get set }
    var pumpDisplayState: CurrentValueSubject<PumpDisplayState?, Never> { get }
    var recommendsLoop: PassthroughSubject<Void, Never> { get }
    var bolusTrigger: PassthroughSubject<Bool, Never> { get }
    var manualTempBasal: PassthroughSubject<Bool, Never> { get }
    var errorSubject: PassthroughSubject<Error, Never> { get }
    var pumpName: CurrentValueSubject<String, Never> { get }
    var pumpExpiresAtDate: CurrentValueSubject<Date?, Never> { get }

    func heartbeat(date: Date)
    func createBolusProgressReporter() -> DoseProgressReporter?
    var alertHistoryStorage: AlertHistoryStorage! { get }
}

private let staticPumpManagers: [PumpManagerUI.Type] = [
    MinimedPumpManager.self,
    OmnipodPumpManager.self,
    OmniBLEPumpManager.self,
    MockPumpManager.self
]

private let staticPumpManagersByIdentifier: [String: PumpManagerUI.Type] = [
    MinimedPumpManager.managerIdentifier: MinimedPumpManager.self,
    OmnipodPumpManager.managerIdentifier: OmnipodPumpManager.self,
    OmniBLEPumpManager.managerIdentifier: OmniBLEPumpManager.self,
    MockPumpManager.managerIdentifier: MockPumpManager.self
]

// private let staticPumpManagersByIdentifier: [String: PumpManagerUI.Type] = staticPumpManagers.reduce(into: [:]) { map, Type in
//    map[Type.managerIdentifier] = Type
// }

private let accessLock = NSRecursiveLock(label: "BaseDeviceDataManager.accessLock")

final class BaseDeviceDataManager: DeviceDataManager, Injectable {
    private let processQueue = DispatchQueue.markedQueue(label: "BaseDeviceDataManager.processQueue")
    @Injected() private var pumpHistoryStorage: PumpHistoryStorage!
    @Injected() var alertHistoryStorage: AlertHistoryStorage!
    @Injected() private var storage: FileStorage!
    @Injected() private var broadcaster: Broadcaster!
    @Injected() private var glucoseStorage: GlucoseStorage!
    @Injected() private var settingsManager: SettingsManager!
    @Injected() private var bluetoothProvider: BluetoothStateManager!

    @Persisted(key: "BaseDeviceDataManager.lastEventDate") var lastEventDate: Date? = nil
    @SyncAccess(lock: accessLock) @Persisted(key: "BaseDeviceDataManager.lastHeartBeatTime") var lastHeartBeatTime: Date =
        .distantPast

    let recommendsLoop = PassthroughSubject<Void, Never>()
    let bolusTrigger = PassthroughSubject<Bool, Never>()
    let errorSubject = PassthroughSubject<Error, Never>()
    let pumpNewStatus = PassthroughSubject<Void, Never>()
    let manualTempBasal = PassthroughSubject<Bool, Never>()

    private let router = FreeAPSApp.resolver.resolve(Router.self)!
    @SyncAccess private var pumpUpdateCancellable: AnyCancellable?
    private var pumpUpdatePromise: Future<Bool, Never>.Promise?
    @SyncAccess var loopInProgress: Bool = false
    private let privateContext = CoreDataStack.shared.persistentContainer.newBackgroundContext()

    var pumpManager: PumpManagerUI? {
        didSet {
            pumpManager?.pumpManagerDelegate = self
            pumpManager?.delegateQueue = processQueue
            UserDefaults.standard.pumpManagerRawValue = pumpManager?.rawValue
            if let pumpManager = pumpManager {
                pumpDisplayState.value = PumpDisplayState(name: pumpManager.localizedTitle, image: pumpManager.smallImage)
                pumpName.send(pumpManager.localizedTitle)

                if let omnipod = pumpManager as? OmnipodPumpManager {
                    guard let endTime = omnipod.state.podState?.expiresAt else {
                        pumpExpiresAtDate.send(nil)
                        return
                    }
                    pumpExpiresAtDate.send(endTime)
                }
                if let omnipodBLE = pumpManager as? OmniBLEPumpManager {
                    guard let endTime = omnipodBLE.state.podState?.expiresAt else {
                        pumpExpiresAtDate.send(nil)
                        return
                    }
                    pumpExpiresAtDate.send(endTime)
                }
            } else {
                pumpDisplayState.value = nil
                pumpExpiresAtDate.send(nil)
                pumpName.send("")
            }
        }
    }

    var bluetoothManager: BluetoothStateManager { bluetoothProvider }

    var hasBLEHeartbeat: Bool {
        (pumpManager as? MockPumpManager) == nil
    }

    let pumpDisplayState = CurrentValueSubject<PumpDisplayState?, Never>(nil)
    let pumpExpiresAtDate = CurrentValueSubject<Date?, Never>(nil)
    let pumpName = CurrentValueSubject<String, Never>("Pump")

    init(resolver: Resolver) {
        injectServices(resolver)
        setupPumpManager()
        UIDevice.current.isBatteryMonitoringEnabled = true
        broadcaster.register(AlertObserver.self, observer: self)
    }

    func setupPumpManager() {
        pumpManager = UserDefaults.standard.pumpManagerRawValue.flatMap { pumpManagerFromRawValue($0) }
    }

    func createBolusProgressReporter() -> DoseProgressReporter? {
        pumpManager?.createBolusProgressReporter(reportingOn: processQueue)
    }

    func heartbeat(date: Date) {
        guard pumpUpdateCancellable == nil else {
            warning(.deviceManager, "Pump updating already in progress. Skip updating.")
            return
        }

        guard !loopInProgress else {
            warning(.deviceManager, "Loop in progress. Skip updating.")
            return
        }

        func update(_: Future<Bool, Never>.Promise?) {}

        processQueue.safeSync {
            lastHeartBeatTime = date
            updatePumpData()
        }
    }

    private func updatePumpData() {
        guard let pumpManager = pumpManager else {
            debug(.deviceManager, "Pump is not set, skip updating")
            updateUpdateFinished(false)
            return
        }

        debug(.deviceManager, "Start updating the pump data")
        processQueue.safeSync {
            pumpManager.ensureCurrentPumpData { _ in
                debug(.deviceManager, "Pump data updated.")
                self.updateUpdateFinished(true)
            }
        }

//        pumpUpdateCancellable = Future<Bool, Never> { [unowned self] promise in
//            pumpUpdatePromise = promise
//            debug(.deviceManager, "Waiting for pump update and loop recommendation")
//            processQueue.safeSync {
//                pumpManager.ensureCurrentPumpData { _ in
//                    debug(.deviceManager, "Pump data updated.")
//                }
//            }
//        }
//        .timeout(30, scheduler: processQueue)
//        .replaceError(with: false)
//        .replaceEmpty(with: false)
//        .sink(receiveValue: updateUpdateFinished)
    }

    private func updateUpdateFinished(_ recommendsLoop: Bool) {
        pumpUpdateCancellable = nil
        pumpUpdatePromise = nil
        if !recommendsLoop {
            warning(.deviceManager, "Loop recommendation time out or got error. Trying to loop right now.")
        }

        // directly in loop() function
//        guard !loopInProgress else {
//            warning(.deviceManager, "Loop already in progress. Skip recommendation.")
//            return
//        }
        self.recommendsLoop.send()
    }

    private func pumpManagerFromRawValue(_ rawValue: [String: Any]) -> PumpManagerUI? {
        guard let rawState = rawValue["state"] as? PumpManager.RawStateValue,
              let Manager = pumpManagerTypeFromRawValue(rawValue)
        else {
            return nil
        }

        return Manager.init(rawState: rawState) as? PumpManagerUI
    }

    private func pumpManagerTypeFromRawValue(_ rawValue: [String: Any]) -> PumpManager.Type? {
        guard let managerIdentifier = rawValue["managerIdentifier"] as? String else {
            return nil
        }

        return staticPumpManagersByIdentifier[managerIdentifier]
    }

    // MARK: - GlucoseSource

    @Persisted(key: "BaseDeviceDataManager.lastFetchGlucoseDate") private var lastFetchGlucoseDate: Date = .distantPast

    var glucoseManager: FetchGlucoseManager?
    var cgmManager: CGMManagerUI?
    var cgmType: CGMType = .enlite

    func fetchIfNeeded() -> AnyPublisher<[BloodGlucose], Never> {
        fetch(nil)
    }

    func fetch(_: DispatchTimer?) -> AnyPublisher<[BloodGlucose], Never> {
        guard let medtronic = pumpManager as? MinimedPumpManager else {
            warning(.deviceManager, "Fetch minilink glucose failed: Pump is not Medtronic")
            return Just([]).eraseToAnyPublisher()
        }

        guard lastFetchGlucoseDate.addingTimeInterval(5.minutes.timeInterval) < Date() else {
            return Just([]).eraseToAnyPublisher()
        }

        medtronic.cgmManagerDelegate = self

        return Future<[BloodGlucose], Error> { promise in
            self.processQueue.async {
                medtronic.fetchNewDataIfNeeded { result in
                    switch result {
                    case .noData:
                        debug(.deviceManager, "Minilink glucose is empty")
                        promise(.success([]))
                    case .unreliableData:
                        debug(.deviceManager, "Unreliable data received")
                        promise(.success([]))
                    case let .newData(glucose):
                        let directions: [BloodGlucose.Direction?] = [nil]
                            + glucose.windows(ofCount: 2).map { window -> BloodGlucose.Direction? in
                                let pair = Array(window)
                                guard pair.count == 2 else { return nil }
                                let firstValue = Int(pair[0].quantity.doubleValue(for: .milligramsPerDeciliter))
                                let secondValue = Int(pair[1].quantity.doubleValue(for: .milligramsPerDeciliter))
                                return .init(trend: secondValue - firstValue)
                            }

                        let results = glucose.enumerated().map { index, sample -> BloodGlucose in
                            let value = Int(sample.quantity.doubleValue(for: .milligramsPerDeciliter))
                            return BloodGlucose(
                                _id: sample.syncIdentifier,
                                sgv: value,
                                direction: directions[index],
                                date: Decimal(Int(sample.date.timeIntervalSince1970 * 1000)),
                                dateString: sample.date,
                                unfiltered: Decimal(value),
                                filtered: nil,
                                noise: nil,
                                glucose: value,
                                type: "sgv"
                            )
                        }
                        if let lastDate = results.last?.dateString {
                            self.lastFetchGlucoseDate = lastDate
                        }

                        promise(.success(results))
                    case let .error(error):
                        warning(.deviceManager, "Fetch minilink glucose failed", error: error)
                        promise(.failure(error))
                    }
                }
            }
        }
        .timeout(60 * 3, scheduler: processQueue, options: nil, customError: nil)
        .replaceError(with: [])
        .replaceEmpty(with: [])
        .eraseToAnyPublisher()
    }
}

// MARK: - PumpManagerDelegate

extension BaseDeviceDataManager: PumpManagerDelegate {
    func pumpManagerPumpWasReplaced(_: PumpManager) {
        debug(.deviceManager, "pumpManagerPumpWasReplaced")
    }

    var detectedSystemTimeOffset: TimeInterval {
        // trustedTimeChecker.detectedSystemTimeOffset
        0
    }

    func pumpManager(_: PumpManager, didAdjustPumpClockBy adjustment: TimeInterval) {
        debug(.deviceManager, "didAdjustPumpClockBy \(adjustment)")
    }

    func pumpManagerDidUpdateState(_ pumpManager: PumpManager) {
        UserDefaults.standard.pumpManagerRawValue = pumpManager.rawValue
        if self.pumpManager == nil, let newPumpManager = pumpManager as? PumpManagerUI {
            self.pumpManager = newPumpManager
        }
        pumpName.send(pumpManager.localizedTitle)
    }

    /// heartbeat with pump occurs some issues in the backgroundtask - so never used
    func pumpManagerBLEHeartbeatDidFire(_: PumpManager) {
        debug(.deviceManager, "Pump Heartbeat: do nothing. Pump connection is OK")
    }

    func pumpManagerMustProvideBLEHeartbeat(_: PumpManager) -> Bool {
        true
    }

    func pumpManager(_ pumpManager: PumpManager, didUpdate status: PumpManagerStatus, oldStatus: PumpManagerStatus) {
        dispatchPrecondition(condition: .onQueue(processQueue))
        debug(.deviceManager, "New pump status Bolus: \(status.bolusState)")
        debug(.deviceManager, "New pump status Basal: \(String(describing: status.basalDeliveryState))")

        if case .inProgress = status.bolusState {
            bolusTrigger.send(true)
        } else {
            bolusTrigger.send(false)
        }

        if status.insulinType != oldStatus.insulinType {
            settingsManager.updateInsulinCurve(status.insulinType)
        }

        let batteryPercent = Int((status.pumpBatteryChargeRemaining ?? 1) * 100)
        let battery = Battery(
            percent: batteryPercent,
            voltage: nil,
            string: batteryPercent >= 10 ? .normal : .low,
            display: pumpManager.status.pumpBatteryChargeRemaining != nil
        )

        privateContext.perform {
            let batteryToStore = OpenAPS_Battery(context: self.privateContext)
            batteryToStore.id = UUID()
            batteryToStore.date = Date()
            batteryToStore.percent = Int16(batteryPercent)
            batteryToStore.voltage = nil
            batteryToStore.status = batteryPercent > 10 ? "normal" : "low"
            batteryToStore.display = status.pumpBatteryChargeRemaining != nil

            do {
                try CoreDataStack.shared.saveContext()
            } catch {
                print(error.localizedDescription)
            }
        }
        broadcaster.notify(PumpTimeZoneObserver.self, on: processQueue) {
            $0.pumpTimeZoneDidChange(status.timeZone)
        }

        if let omnipod = pumpManager as? OmnipodPumpManager {
            let reservoirVal = omnipod.state.podState?.lastInsulinMeasurements?.reservoirLevel ?? 0xDEAD_BEEF
            // TODO: find the value Pod.maximumReservoirReading
            let reservoir = Decimal(reservoirVal) > 50.0 ? 0xDEAD_BEEF : reservoirVal

            storage.save(Decimal(reservoir), as: OpenAPS.Monitor.reservoir)
            broadcaster.notify(PumpReservoirObserver.self, on: processQueue) {
                $0.pumpReservoirDidChange(Decimal(reservoir))
            }

            if let tempBasal = omnipod.state.podState?.unfinalizedTempBasal, !tempBasal.isFinished(),
               !tempBasal.automatic
            {
                // the manual basal temp is launch - block every thing
                debug(.deviceManager, "manual temp basal")
                manualTempBasal.send(true)
            } else {
                // no more manual Temp Basal !
                manualTempBasal.send(false)
            }

            guard let endTime = omnipod.state.podState?.expiresAt else {
                pumpExpiresAtDate.send(nil)
                return
            }
            pumpExpiresAtDate.send(endTime)

            if let startTime = omnipod.state.podState?.activatedAt {
                storage.save(startTime, as: OpenAPS.Monitor.podAge)
            }
        }

        if let omnipodBLE = pumpManager as? OmniBLEPumpManager {
            let reservoirVal = omnipodBLE.state.podState?.lastInsulinMeasurements?.reservoirLevel ?? 0xDEAD_BEEF
            // TODO: find the value Pod.maximumReservoirReading
            let reservoir = Decimal(reservoirVal) > 50.0 ? 0xDEAD_BEEF : reservoirVal

            storage.save(Decimal(reservoir), as: OpenAPS.Monitor.reservoir)
            broadcaster.notify(PumpReservoirObserver.self, on: processQueue) {
                $0.pumpReservoirDidChange(Decimal(reservoir))
            }

            // manual temp basal on
            if let tempBasal = omnipodBLE.state.podState?.unfinalizedTempBasal, !tempBasal.isFinished(),
               !tempBasal.automatic
            {
                // the manual basal temp is launch - block every thing
                debug(.deviceManager, "manual temp basal")
                manualTempBasal.send(true)
            } else {
                // no more manual Temp Basal !
                manualTempBasal.send(false)
            }

            guard let endTime = omnipodBLE.state.podState?.expiresAt else {
                pumpExpiresAtDate.send(nil)
                return
            }
            pumpExpiresAtDate.send(endTime)

            if let startTime = omnipodBLE.state.podState?.activatedAt {
                storage.save(startTime, as: OpenAPS.Monitor.podAge)
            }
        }
    }

    func pumpManagerWillDeactivate(_: PumpManager) {
        dispatchPrecondition(condition: .onQueue(processQueue))
        pumpManager = nil
    }

    func pumpManager(_: PumpManager, didUpdatePumpRecordsBasalProfileStartEvents _: Bool) {}

    func pumpManager(_: PumpManager, didError error: PumpManagerError) {
        dispatchPrecondition(condition: .onQueue(processQueue))
        debug(.deviceManager, "error: \(error.localizedDescription), reason: \(String(describing: error.failureReason))")
        errorSubject.send(error)
    }

    func pumpManager(
        _: PumpManager,
        hasNewPumpEvents events: [NewPumpEvent],
        lastReconciliation _: Date?,
        completion: @escaping (_ error: Error?) -> Void
    ) {
        dispatchPrecondition(condition: .onQueue(processQueue))
        debug(.deviceManager, "New pump events:\n\(events.map(\.title).joined(separator: "\n"))")

        // filter buggy TBRs > maxBasal from MDT
        let events = events.filter {
            // type is optional...
            guard let type = $0.type, type == .tempBasal else { return true }
            return $0.dose?.unitsPerHour ?? 0 <= Double(settingsManager.pumpSettings.maxBasal)
        }
        pumpHistoryStorage.storePumpEvents(events)
        lastEventDate = events.last?.date
        completion(nil)
    }

    func pumpManager(
        _: PumpManager,
        didReadReservoirValue units: Double,
        at date: Date,
        completion: @escaping (Result<
            (newValue: ReservoirValue, lastValue: ReservoirValue?, areStoredValuesContinuous: Bool),
            Error
        >) -> Void
    ) {
        dispatchPrecondition(condition: .onQueue(processQueue))
        debug(.deviceManager, "Reservoir Value \(units), at: \(date)")
        storage.save(Decimal(units), as: OpenAPS.Monitor.reservoir)
        broadcaster.notify(PumpReservoirObserver.self, on: processQueue) {
            $0.pumpReservoirDidChange(Decimal(units))
        }

        completion(.success((
            newValue: Reservoir(startDate: Date(), unitVolume: units),
            lastValue: nil,
            areStoredValuesContinuous: true
        )))
    }

    func pumpManagerRecommendsLoop(_: PumpManager) {
        dispatchPrecondition(condition: .onQueue(processQueue))
        debug(.deviceManager, "Pump recommends loop")
        guard let promise = pumpUpdatePromise else {
            warning(.deviceManager, "We do not waiting for loop recommendation at this time.")
            return
        }
        promise(.success(true))
    }

    func startDateToFilterNewPumpEvents(for _: PumpManager) -> Date {
        lastEventDate?.addingTimeInterval(-15.minutes.timeInterval) ?? Date().addingTimeInterval(-2.hours.timeInterval)
    }
}

// MARK: - DeviceManagerDelegate

extension BaseDeviceDataManager: DeviceManagerDelegate {
    func issueAlert(_ alert: Alert) {
        alertHistoryStorage.storeAlert(
            AlertEntry(
                alertIdentifier: alert.identifier.alertIdentifier,
                primitiveInterruptionLevel: alert.interruptionLevel.storedValue as? Decimal,
                issuedDate: Date(),
                managerIdentifier: alert.identifier.managerIdentifier,
                triggerType: alert.trigger.storedType,
                triggerInterval: alert.trigger.storedInterval as? Decimal,
                contentTitle: alert.foregroundContent?.title,
                contentBody: alert.foregroundContent?.body
            )
        )
    }

    func retractAlert(identifier: Alert.Identifier) {
        alertHistoryStorage.deleteAlert(identifier: identifier.alertIdentifier)
    }

    func doesIssuedAlertExist(identifier _: Alert.Identifier, completion _: @escaping (Result<Bool, Error>) -> Void) {
        debug(.deviceManager, "doesIssueAlertExist")
    }

    func lookupAllUnretracted(managerIdentifier _: String, completion _: @escaping (Result<[PersistedAlert], Error>) -> Void) {
        debug(.deviceManager, "lookupAllUnretracted")
    }

    func lookupAllUnacknowledgedUnretracted(
        managerIdentifier _: String,
        completion _: @escaping (Result<[PersistedAlert], Error>) -> Void
    ) {}

    func recordRetractedAlert(_: Alert, at _: Date) {}

//    func scheduleNotification(
//        for _: DeviceManager,
//        identifier: String,
//        content: UNNotificationContent,
//        trigger: UNNotificationTrigger?
//    ) {
//        let request = UNNotificationRequest(
//            identifier: identifier,
//            content: content,
//            trigger: trigger
//        )
//
//        DispatchQueue.main.async {
//            UNUserNotificationCenter.current().add(request)
//        }
//    }
//
//    func clearNotification(for _: DeviceManager, identifier: String) {
//        DispatchQueue.main.async {
//            UNUserNotificationCenter.current().removeDeliveredNotifications(withIdentifiers: [identifier])
//        }
//    }

    func removeNotificationRequests(for _: DeviceManager, identifiers: [String]) {
        DispatchQueue.main.async {
            UNUserNotificationCenter.current().removePendingNotificationRequests(withIdentifiers: identifiers)
        }
    }

    func deviceManager(
        _: DeviceManager,
        logEventForDeviceIdentifier _: String?,
        type _: DeviceLogEntryType,
        message: String,
        completion _: ((Error?) -> Void)?
    ) {
        debug(.deviceManager, "Device message: \(message)")
    }
}

// MARK: - CGMManagerDelegate

extension BaseDeviceDataManager: CGMManagerDelegate {
    func startDateToFilterNewData(for _: CGMManager) -> Date? {
        glucoseStorage.syncDate().addingTimeInterval(-10.minutes.timeInterval) // additional time to calculate directions
    }

    func cgmManager(_: CGMManager, hasNew _: CGMReadingResult) {}

    func cgmManagerWantsDeletion(_: CGMManager) {}

    func cgmManagerDidUpdateState(_: CGMManager) {}

    func credentialStoragePrefix(for _: CGMManager) -> String { "BaseDeviceDataManager" }

    func cgmManager(_: CGMManager, didUpdate _: CGMManagerStatus) {}
}

// MARK: - AlertPresenter

extension BaseDeviceDataManager: AlertObserver {
    func AlertDidUpdate(_ alerts: [AlertEntry]) {
        alerts.forEach { alert in
            if alert.acknowledgedDate == nil {
                ackAlert(alert: alert)
            }
        }
    }

    private func ackAlert(alert: AlertEntry) {
        let typeMessage: MessageType
        let alertUp = alert.alertIdentifier.uppercased()
        if alertUp.contains("FAULT") || alertUp.contains("ERROR") {
            typeMessage = .errorPump
        } else {
            typeMessage = .warning
        }

        let messageCont = MessageContent(content: alert.contentBody ?? "Unknown", type: typeMessage)
        let alertIssueDate = alert.issuedDate

        processQueue.async {
            // if not alert in OmniPod/BLE, the acknowledgeAlert didn't do callbacks- Hack to manage this case
            if let omnipodBLE = self.pumpManager as? OmniBLEPumpManager {
                if omnipodBLE.state.activeAlerts.isEmpty {
                    // force to ack alert in the alertStorage
                    self.alertHistoryStorage.ackAlert(alertIssueDate, nil)
                }
            }

            if let omniPod = self.pumpManager as? OmnipodPumpManager {
                if omniPod.state.activeAlerts.isEmpty {
                    // force to ack alert in the alertStorage
                    self.alertHistoryStorage.ackAlert(alertIssueDate, nil)
                }
            }

            self.pumpManager?.acknowledgeAlert(alertIdentifier: alert.alertIdentifier) { error in
                self.router.alertMessage.send(messageCont)
                if let error = error {
                    self.alertHistoryStorage.ackAlert(alertIssueDate, error.localizedDescription)
                    debug(.deviceManager, "acknowledge not succeeded with error \(error.localizedDescription)")
                } else {
                    self.alertHistoryStorage.ackAlert(alertIssueDate, nil)
                }
            }

            self.broadcaster.notify(pumpNotificationObserver.self, on: self.processQueue) {
                $0.pumpNotification(alert: alert)
            }
        }
    }
}

// extension BaseDeviceDataManager: AlertPresenter {
//    func issueAlert(_: Alert) {}
//    func retractAlert(identifier _: Alert.Identifier) {}
// }

// MARK: Others

protocol PumpReservoirObserver {
    func pumpReservoirDidChange(_ reservoir: Decimal)
}

protocol PumpBatteryObserver {
    func pumpBatteryDidChange(_ battery: Battery)
}

protocol PumpTimeZoneObserver {
    func pumpTimeZoneDidChange(_ timezone: TimeZone)
}