//

//  File.swift

//  USB Meter

//

//  Created by Bogdan Timofte on 03/03/2020.

//  Copyright © 2020 Bogdan Timofte. All rights reserved.

//

//MARK: Store and documentation: https://www.aliexpress.com/item/32968303350.html

//MARK: Protocol: https://sigrok.org/wiki/RDTech_UM_series

//MARK: Pithon Code: https://github.com/rfinnie/rdserialtool

//MARK: HM-10 Code: https://github.com/hoiberg/HM10-BluetoothSerial-iOS

//MARK: Package dependency https://github.com/krzyzanowskim/CryptoSwift

import CoreBluetooth

import SwiftUI

/**

 Supprted USB Meters

 # UM25C

 # TC66

 * Reverse Engineering

 [UM Series](https://sigrok.org/wiki/RDTech_UM_series)

 [TC66C](https://sigrok.org/wiki/RDTech_TC66C)

 */

    case UM34C

    case TC66C

}

    case celsius

    case fahrenheit

    var id: String { rawValue }

    var title: String {

        switch self {

        case .celsius:

            return "Celsius"

        case .fahrenheit:

            return "Fahrenheit"

        }

    }

    var symbol: String {

        switch self {

        case .celsius:

            return "℃"

        case .fahrenheit:

            return "℉"

        }

    }

}

enum ChargeRecordState {

    case waitingForStart

    case active

    case completed

}

    enum OperationalState: Int, Comparable {

        case notPresent

        case peripheralNotConnected

        case peripheralConnectionPending

        case peripheralConnected

        case peripheralReady

        case comunicating

        case dataIsAvailable

        static func < (lhs: OperationalState, rhs: OperationalState) -> Bool {

            return lhs.rawValue < rhs.rawValue

        }

    }

    @Published var operationalState = OperationalState.peripheralNotConnected {

        didSet {

            switch operationalState {

            case .notPresent:

                break

            case .peripheralNotConnected:

                if enableAutoConnect {

                    track("\(name) - Reconnecting...")

                    btSerial.connect()

                }

            case .peripheralConnectionPending:

                break

            case .peripheralConnected:

                break

            case .peripheralReady:

                DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) { // Change `2.0` to the desired number of seconds.

                    self.dataDumpRequest()

                }

            case .comunicating:

                break

            case .dataIsAvailable:

                break

            }

        }

    }

    static func operationalColor(for state: OperationalState) -> Color {

        switch state {

        case .notPresent:

            return .red

        case .peripheralNotConnected:

            return .blue

        case .peripheralConnectionPending:

            return .yellow

        case .peripheralConnected:

            return .yellow

        case .peripheralReady:

            return .orange

        case .comunicating:

            return .orange

        case .dataIsAvailable:

            return .green

        }

    }

    private var wdTimer: Timer?

    @Published var lastSeen = Date() {

        didSet {

            wdTimer?.invalidate()

            if operationalState == .peripheralNotConnected {

                wdTimer = Timer.scheduledTimer(withTimeInterval: 20, repeats: false, block: {_ in

                    track("\(self.name) - Lost advertisments...")

                    self.operationalState = .notPresent

                })

            } else if operationalState == .notPresent {

               operationalState = .peripheralNotConnected

            }

        }

    }

    var uuid: UUID

    var model: Model

    var modelString: String

    var name: String {

        didSet {

            appData.meterNames[btSerial.macAddress.description] = name

        }

    }

    var color : Color {

        get {

    }

        model.capabilities

    }

    var supportsDataGroupCommands: Bool {

        capabilities.supportsRecordingView

    }

    var supportsRecordingThreshold: Bool {

        capabilities.reportsCurrentScreenIndex

    }

    var showsDataGroupEnergy: Bool {

        capabilities.showsDataGroupEnergy

    }

    var highlightsActiveDataGroup: Bool {

        if model == .TC66C {

            return hasObservedActiveDataGroup

        }

        return capabilities.highlightsActiveDataGroup

    }

        model == .TC66C

    }

    }

        capabilities.dataGroupsTitle

    }

        capabilities.documentedWorkingVoltage

    }

        capabilities.chargerTypeDescription(for: chargerTypeIndex)

        if supportsManualTemperatureUnitSelection {

            return tc66TemperatureUnitPreference.title

        }

        return supportsFahrenheit ? "Celsius / Fahrenheit" : "Celsius"

    }

    var primaryTemperatureDescription: String {

        let value = temperatureCelsius.format(decimalDigits: 0)

        if supportsManualTemperatureUnitSelection {

            return "\(value)\(tc66TemperatureUnitPreference.symbol)"

        }

        if let symbol = capabilities.primaryTemperatureUnitSymbol {

            return "\(value)\(symbol)"

        }

        return value

    }

    var secondaryTemperatureDescription: String? {

        guard supportsFahrenheit else { return nil }

        return "\(temperatureFahrenheit.format(decimalDigits: 0))℉"

    }

            return "Page Controls"

        }

            return "Screen \(currentScreen): \(label)"

        }

        return "Screen \(currentScreen)"

    }

        let baseName = reportedModelName.isEmpty ? modelString : reportedModelName

        if modelNumber != 0 {

            return "\(baseName) (\(modelNumber))"

        }

        return baseName

    }

        let totalSeconds = Int(recordingDuration)

        let hours = totalSeconds / 3600

        let minutes = (totalSeconds % 3600) / 60

        let seconds = totalSeconds % 60

        if hours > 0 {

            return String(format: "%d:%02d:%02d", hours, minutes, seconds)

        }

        return String(format: "%02d:%02d", minutes, seconds)

    }

        let totalSeconds = Int(chargeRecordDuration)

        let hours = totalSeconds / 3600

        let minutes = (totalSeconds % 3600) / 60

        let seconds = totalSeconds % 60

        if hours > 0 {

            return String(format: "%d:%02d:%02d", hours, minutes, seconds)

        }

        return String(format: "%02d:%02d", minutes, seconds)

    }

    var chargeRecordTimeRange: ClosedRange<Date>? {

        guard let start = chargeRecordStartTimestamp else { return nil }

        let end = chargeRecordEndTimestamp ?? chargeRecordLastTimestamp

        guard let end else { return nil }

        return start...end

    }

    var chargeRecordStatusText: String {

        switch chargeRecordState {

        case .waitingForStart:

            return "Waiting"

        case .active:

            return "Active"

        case .completed:

            return "Completed"

        }

    }

    var chargeRecordStatusColor: Color {

        switch chargeRecordState {

        case .waitingForStart:

            return .secondary

        case .active:

            return .red

        case .completed:

            return .green

        }

    }

            if hasObservedActiveDataGroup {

                return "The active memory is inferred from the totals that are currently increasing."

            }

            return "The device exposes two read-only memories. The active memory is inferred once one total starts increasing."

        }

        return capabilities.dataGroupsHint

    }

    func dataGroupLabel(for id: UInt8) -> String {

        supportsDataGroupCommands ? "\(id)" : "M\(Int(id) + 1)"

    var recordingThresholdHint: String? {

        capabilities.recordingThresholdHint

    }

    @Published var measurements = Measurements()

    private var commandQueue: [Data] = []

    private var dataDumpRequestTimestamp = Date()

    class DataGroupRecord {

        @Published var ah: Double

        @Published var wh: Double

        init(ah: Double, wh: Double) {

            self.ah = ah

            self.wh = wh

        }

    }

    @Published var selectedDataGroup: UInt8 = 0

    @Published var dataGroupRecords: [Int : DataGroupRecord] = [:]

    @Published var chargeRecordWH: Double = 0

    @Published var chargeRecordDuration: TimeInterval = 0

    @Published var chargeRecordStopThreshold: Double = 0.05

    @Published var tc66TemperatureUnitPreference: TemperatureUnitPreference = .celsius {

        didSet {

            guard supportsManualTemperatureUnitSelection else { return }

            guard oldValue != tc66TemperatureUnitPreference else { return }

            var settings = appData.tc66TemperatureUnits

            settings[btSerial.macAddress.description] = tc66TemperatureUnitPreference.rawValue

            appData.tc66TemperatureUnits = settings

        }

    }

    @Published var screenBrightness: Int = -1 {

        didSet {

            if oldValue != screenBrightness {

                screenBrightnessTimestamp = Date()

                if oldValue != -1 {

                    setSceeenBrightness(to: UInt8(screenBrightness))

                }

            }

        }

    }

    private var screenBrightnessTimestamp = Date()

    @Published var screenTimeout: Int = -1 {

        didSet {

            if oldValue != screenTimeout {

                screenTimeoutTimestamp = Date()

                if oldValue != -1 {

                    setScreenSaverTimeout(to: UInt8(screenTimeout))

                }

            }

        }

    }

    private var screenTimeoutTimestamp = Date()

    @Published var voltage: Double = 0

    @Published var current: Double = 0

    @Published var power: Double = 0

    @Published var temperatureCelsius: Double = 0

    @Published var temperatureFahrenheit: Double = 0

    @Published var usbPlusVoltage: Double = 0

    @Published var usbMinusVoltage: Double = 0

    @Published var recordedAH: Double = 0

    @Published var recordedWH: Double = 0

    @Published var recording: Bool = false

            if isApplyingRecordingThresholdFromDevice {

                return

            guard recordingThresholdLoadedFromDevice else { return }

            setrecordingTreshold(to: (recordingTreshold * 100).uInt8Value)

    @Published var recordingDuration: UInt32 = 0

    @Published var loadResistance: Double = 0

    @Published var modelNumber: UInt16 = 0

    @Published var chargerTypeIndex: UInt16 = 0

    @Published var firmwareVersion: String = ""

    @Published var serialNumber: UInt32 = 0

    @Published var bootCount: UInt32 = 0

    private var recordingThresholdLoadedFromDevice = false

    private var isApplyingRecordingThresholdFromDevice = false

    private var chargeRecordStartTimestamp: Date?

    private var chargeRecordEndTimestamp: Date?

    private var chargeRecordLastTimestamp: Date?

    private var chargeRecordLastCurrent: Double = 0

    private var chargeRecordLastPower: Double = 0

    private var hasObservedActiveDataGroup = false

    private var hasSeenTC66Snapshot = false

    init ( model: Model, with serialPort: BluetoothSerial ) {

        uuid = serialPort.peripheral.identifier

        //dataStore.meterUUIDS.append(serialPort.peripheral.identifier)

        modelString = serialPort.peripheral.name!

        self.model = model

        btSerial = serialPort

        name = appData.meterNames[serialPort.macAddress.description] ?? serialPort.macAddress.description

        super.init()

        btSerial.delegate = self

        for index in stride(from: 0, through: 9, by: 1) {

            dataGroupRecords[index] = DataGroupRecord(ah:0, wh: 0)

        }

    }

    func reloadTemperatureUnitPreference() {

        guard supportsManualTemperatureUnitSelection else { return }

        let rawValue = appData.tc66TemperatureUnits[btSerial.macAddress.description] ?? TemperatureUnitPreference.celsius.rawValue

        let persistedPreference = TemperatureUnitPreference(rawValue: rawValue) ?? .celsius

        if tc66TemperatureUnitPreference != persistedPreference {

            tc66TemperatureUnitPreference = persistedPreference

        }

    }

    func dataDumpRequest() {

        if commandQueue.isEmpty {

            switch model {

            case .UM25C:

            dataDumpRequestTimestamp = Date()

            // track("\(name) - Request sent!")

        } else {

            track("Request delayed for: \(commandQueue.first!.hexEncodedStringValue)")

            btSerial.write( commandQueue.first! )

            commandQueue.removeFirst()

            DispatchQueue.main.asyncAfter( deadline: .now() + 1 )  {

                self.dataDumpRequest()

            }

        }

    }

    /**

     received data parser

     - parameter buffer cotains response for data dump request

     - Decription metod for TC66C AES ECB response  found [here](https:github.com/krzyzanowskim/CryptoSwift/issues/693)

     */

    func parseData ( from buffer: Data) {

        //track("\(name)")

        switch model {

        case .UM25C:

                apply(umSnapshot: try UMProtocol.parseSnapshot(from: buffer, model: model))

            } catch {

                track("\(name) - Error: \(error)")

            }

                apply(umSnapshot: try UMProtocol.parseSnapshot(from: buffer, model: model))

            } catch {

                track("\(name) - Error: \(error)")

            }

                apply(tc66Snapshot: try TC66Protocol.parseSnapshot(from: buffer))

            } catch {

                track("\(name) - Error: \(error)")

            }

//        DispatchQueue.global(qos: .userInitiated).asyncAfter( deadline: .now() + 0.33 ) {

//            //track("\(name) - Scheduled new request.")

//        }

        operationalState = .dataIsAvailable

        dataDumpRequest()

    }

        modelNumber = snapshot.modelNumber

        voltage = snapshot.voltage

        current = snapshot.current

        power = snapshot.power

        temperatureCelsius = snapshot.temperatureCelsius

        temperatureFahrenheit = snapshot.temperatureFahrenheit

        selectedDataGroup = snapshot.selectedDataGroup

        for (index, record) in snapshot.dataGroupRecords {

            dataGroupRecords[index] = DataGroupRecord(ah: record.ah, wh: record.wh)

        usbMinusVoltage = snapshot.usbMinusVoltage

        chargerTypeIndex = snapshot.chargerTypeIndex

        recordedAH = snapshot.recordedAH

        recordedWH = snapshot.recordedWH

        if recordingThresholdTimestamp < dataDumpRequestTimestamp || !recordingThresholdLoadedFromDevice {

            recordingThresholdLoadedFromDevice = true

            if recordingTreshold != snapshot.recordingThreshold {

                isApplyingRecordingThresholdFromDevice = true

                recordingTreshold = snapshot.recordingThreshold

                isApplyingRecordingThresholdFromDevice = false

            }

        } else {

            track("\(name) - Skip updating recordingThreshold (changed after request).")

        }

        recording = snapshot.recording

                screenTimeout = snapshot.screenTimeout

        } else {

            track("\(name) - Skip updating screenTimeout (changed after request).")

        }

        if screenBrightnessTimestamp < dataDumpRequestTimestamp {

                screenBrightness = snapshot.screenBrightness

        } else {

            track("\(name) - Skip updating screenBrightness (changed after request).")

        }

        loadResistance = snapshot.loadResistance

            inferTC66ActiveDataGroup(from: snapshot)

        } else {

            hasSeenTC66Snapshot = true

        }

        firmwareVersion = snapshot.firmwareVersion

        serialNumber = snapshot.serialNumber

        bootCount = snapshot.bootCount

        current = snapshot.current

        power = snapshot.power

        loadResistance = snapshot.loadResistance

        for (index, record) in snapshot.dataGroupRecords {

            dataGroupRecords[index] = DataGroupRecord(ah: record.ah, wh: record.wh)

        usbPlusVoltage = snapshot.usbPlusVoltage

        usbMinusVoltage = snapshot.usbMinusVoltage

    private func inferTC66ActiveDataGroup(from snapshot: TC66Snapshot) {

        let candidate = snapshot.dataGroupRecords.compactMap { entry -> (UInt8, Double)? in

            let index = entry.key

            let record = entry.value

            guard let previous = dataGroupRecords[index] else { return nil }

            let deltaAH = max(record.ah - previous.ah, 0)

            let deltaWH = max(record.wh - previous.wh, 0)

            let score = deltaAH + deltaWH

            guard score > 0 else { return nil }

            return (UInt8(index), score)

        }

        .max { lhs, rhs in lhs.1 < rhs.1 }

        if let candidate {

            selectedDataGroup = candidate.0

            hasObservedActiveDataGroup = true

        }

    }

    private func updateChargeRecord(at timestamp: Date) {

        switch chargeRecordState {

        case .waitingForStart:

            guard current > chargeRecordStopThreshold else { return }

            chargeRecordState = .active

            chargeRecordStartTimestamp = timestamp

            chargeRecordEndTimestamp = timestamp

            chargeRecordLastTimestamp = timestamp

            chargeRecordLastCurrent = current

            chargeRecordLastPower = power

        case .active:

            if let lastTimestamp = chargeRecordLastTimestamp {

                let deltaSeconds = max(timestamp.timeIntervalSince(lastTimestamp), 0)

                chargeRecordAH += chargeRecordLastCurrent * deltaSeconds / 3600

                chargeRecordWH += chargeRecordLastPower * deltaSeconds / 3600

                chargeRecordDuration += deltaSeconds

            }

            chargeRecordEndTimestamp = timestamp

            chargeRecordLastTimestamp = timestamp

            chargeRecordLastCurrent = current

            chargeRecordLastPower = power

            if current <= chargeRecordStopThreshold {

                chargeRecordState = .completed

            }

        case .completed:

            break

        }

    }

    func resetChargeRecord() {

        chargeRecordAH = 0

        chargeRecordWH = 0

        chargeRecordDuration = 0

        chargeRecordState = .waitingForStart

        chargeRecordStartTimestamp = nil

        chargeRecordEndTimestamp = nil

        chargeRecordLastTimestamp = nil

        chargeRecordLastCurrent = 0

        chargeRecordLastPower = 0

    }

    func resetChargeRecordGraph() {

        let cutoff = Date()

        resetChargeRecord()

        measurements.trim(before: cutoff)

    }

    func nextScreen() {

        switch model {

        case .UM25C:

    }

    func rotateScreen() {

        switch model {

        case .UM25C:

    }

    func previousScreen() {

        switch model {

        case .UM25C:

    }

    func clear() {

    func clear(group id: UInt8) {

    func selectDataGroup ( id: UInt8) {

        selectedDataGroup = id

    private func setSceeenBrightness ( to value: UInt8) {

        track("\(name) - \(value)")

    private func setScreenSaverTimeout ( to value: UInt8) {

        track("\(name) - \(value)")

    func setrecordingTreshold ( to value: UInt8) {

    /**

     Connect to meter.

     1. It calls BluetoothSerial.connect

     */

    func connect() {

        enableAutoConnect = true

        btSerial.connect()

    }

    /**

     Disconnect from meter.

        It calls BluetoothSerial.disconnect

     */

    func disconnect() {

        enableAutoConnect = false

        btSerial.disconnect()

    }

}

extension Meter : SerialPortDelegate {

    func opertionalStateChanged(to serialPortOperationalState: BluetoothSerial.OperationalState) {

        lastSeen = Date()

        //track("\(name) - \(serialPortOperationalState)")

        switch serialPortOperationalState {

        case .peripheralNotConnected:

            operationalState = .peripheralNotConnected

        case .peripheralConnectionPending:

            operationalState = .peripheralConnectionPending

        case .peripheralConnected:

            operationalState = .peripheralConnected

        case .peripheralReady:

            operationalState = .peripheralReady

        }

    }

    func didReceiveData(_ data: Data) {

        lastSeen = Date()

        operationalState = .comunicating

        parseData(from: data)

    }

}