package com.geeksville.mesh.ui

import android.annotation.SuppressLint
import android.app.Application
import android.app.PendingIntent
import android.bluetooth.BluetoothDevice
import android.bluetooth.BluetoothDevice.BOND_BONDED
import android.bluetooth.BluetoothDevice.BOND_BONDING
import android.bluetooth.le.*
import android.companion.AssociationRequest
import android.companion.BluetoothDeviceFilter
import android.companion.CompanionDeviceManager
import android.content.*
import android.content.pm.PackageManager
import android.hardware.usb.UsbDevice
import android.hardware.usb.UsbManager
import android.os.*
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.view.inputmethod.EditorInfo
import android.widget.*
import androidx.activity.result.IntentSenderRequest
import androidx.activity.result.contract.ActivityResultContracts
import androidx.fragment.app.activityViewModels
import androidx.lifecycle.AndroidViewModel
import androidx.lifecycle.MutableLiveData
import com.geeksville.analytics.DataPair
import com.geeksville.android.GeeksvilleApplication
import com.geeksville.android.Logging
import com.geeksville.android.hideKeyboard
import com.geeksville.android.isGooglePlayAvailable
import com.geeksville.mesh.MainActivity
import com.geeksville.mesh.R
import com.geeksville.mesh.RadioConfigProtos
import com.geeksville.mesh.android.*
import com.geeksville.mesh.databinding.SettingsFragmentBinding
import com.geeksville.mesh.model.BluetoothViewModel
import com.geeksville.mesh.model.UIViewModel
import com.geeksville.mesh.repository.radio.BluetoothInterface
import com.geeksville.mesh.repository.radio.MockInterface
import com.geeksville.mesh.repository.radio.RadioInterfaceService
import com.geeksville.mesh.repository.radio.SerialInterface
import com.geeksville.mesh.repository.usb.UsbRepository
import com.geeksville.mesh.service.*
import com.geeksville.mesh.service.SoftwareUpdateService.Companion.ACTION_UPDATE_PROGRESS
import com.geeksville.mesh.service.SoftwareUpdateService.Companion.ProgressNotStarted
import com.geeksville.mesh.service.SoftwareUpdateService.Companion.ProgressSuccess
import com.geeksville.util.anonymize
import com.geeksville.util.exceptionReporter
import com.geeksville.util.exceptionToSnackbar
import com.google.android.gms.location.LocationRequest
import com.google.android.gms.location.LocationServices
import com.google.android.gms.location.LocationSettingsRequest
import com.google.android.material.dialog.MaterialAlertDialogBuilder
import com.google.android.material.snackbar.Snackbar
import com.hoho.android.usbserial.driver.UsbSerialDriver
import dagger.hilt.android.AndroidEntryPoint
import dagger.hilt.android.lifecycle.HiltViewModel
import kotlinx.coroutines.Job
import java.util.regex.Pattern
import javax.inject.Inject

object SLogging : Logging

/// Change to a new macaddr selection, updating GUI and radio
fun changeDeviceSelection(context: MainActivity, newAddr: String?) {
    // FIXME, this is a kinda yucky way to find the service
    context.model.meshService?.let { service ->
        MeshService.changeDeviceAddress(context, service, newAddr)
    }
}

/// Show the UI asking the user to bond with a device, call changeSelection() if/when bonding completes
@SuppressLint("MissingPermission")
private fun requestBonding(
    activity: MainActivity,
    device: BluetoothDevice,
    onComplete: (Int) -> Unit
) {
    SLogging.info("Starting bonding for ${device.anonymize}")

    // We need this receiver to get informed when the bond attempt finished
    val bondChangedReceiver = object : BroadcastReceiver() {

        override fun onReceive(
            context: Context,
            intent: Intent
        ) = exceptionReporter {
            val state =
                intent.getIntExtra(
                    BluetoothDevice.EXTRA_BOND_STATE,
                    -1
                )
            SLogging.debug("Received bond state changed $state")

            if (state != BOND_BONDING) {
                context.unregisterReceiver(this) // we stay registered until bonding completes (either with BONDED or NONE)
                SLogging.debug("Bonding completed, state=$state")
                onComplete(state)
            }
        }
    }

    val filter = IntentFilter()
    filter.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED)
    activity.registerReceiver(bondChangedReceiver, filter)

    // We ignore missing BT adapters, because it lets us run on the emulator
    try {
        device.createBond()
    } catch (ex: Throwable) {
        SLogging.warn("Failed creating Bluetooth bond: ${ex.message}")
    }
}

@HiltViewModel
class BTScanModel @Inject constructor(
    private val usbRepository: UsbRepository,
    app: Application
) : AndroidViewModel(app), Logging {

    private val context: Context get() = getApplication<Application>().applicationContext

    init {
        debug("BTScanModel created")
    }

    open class DeviceListEntry(val name: String, val address: String, val bonded: Boolean) {
        val bluetoothAddress
            get() =
                if (isBluetooth)
                    address.substring(1)
                else
                    null

        override fun toString(): String {
            return "DeviceListEntry(name=${name.anonymize}, addr=${address.anonymize})"
        }

        val isBluetooth: Boolean get() = address[0] == 'x'
        val isSerial: Boolean get() = address[0] == 's'
    }

    class USBDeviceListEntry(usbManager: UsbManager, val usb: UsbSerialDriver) : DeviceListEntry(
        usb.device.deviceName,
        SerialInterface.toInterfaceName(usb.device.deviceName),
        SerialInterface.assumePermission || usbManager.hasPermission(usb.device)
    )

    override fun onCleared() {
        super.onCleared()
        debug("BTScanModel cleared")
    }

    val bluetoothAdapter = context.bluetoothManager?.adapter
    private val usbManager get() = context.usbManager

    var selectedAddress: String? = null
    val errorText = object : MutableLiveData<String?>(null) {}

    private var scanner: BluetoothLeScanner? = null

    /// If this address is for a bluetooth device, return the macaddr portion, else null
    val selectedBluetooth: String?
        get() = selectedAddress?.let { a ->
            if (a[0] == 'x')
                a.substring(1)
            else
                null
        }

    /// If this address is for a USB device, return the macaddr portion, else null
    val selectedUSB: String?
        get() = selectedAddress?.let { a ->
            if (a[0] == 's')
                a.substring(1)
            else
                null
        }

    /// Use the string for the NopInterface
    val selectedNotNull: String get() = selectedAddress ?: "n"

    private val scanCallback = object : ScanCallback() {
        override fun onScanFailed(errorCode: Int) {
            val msg = "Unexpected bluetooth scan failure: $errorCode"
            errormsg(msg)
            // error code2 seeems to be indicate hung bluetooth stack
            errorText.value = msg
        }

        // For each device that appears in our scan, ask for its GATT, when the gatt arrives,
        // check if it is an eligable device and store it in our list of candidates
        // if that device later disconnects remove it as a candidate
        @SuppressLint("MissingPermission")
        override fun onScanResult(callbackType: Int, result: ScanResult) {

            if ((result.device.name?.startsWith("Mesh") == true)) {
                val addr = result.device.address
                val fullAddr = "x$addr" // full address with the bluetooth prefix added
                // prevent logspam because weill get get lots of redundant scan results
                val isBonded = result.device.bondState == BOND_BONDED
                val oldDevs = devices.value!!
                val oldEntry = oldDevs[fullAddr]
                if (oldEntry == null || oldEntry.bonded != isBonded) { // Don't spam the GUI with endless updates for non changing nodes
                    val entry = DeviceListEntry(
                        result.device.name
                            ?: "unnamed-$addr", // autobug: some devices might not have a name, if someone is running really old device code?
                        fullAddr,
                        isBonded
                    )
                    // If nothing was selected, by default select the first valid thing we see
                    val activity: MainActivity? = try {
                        GeeksvilleApplication.currentActivity as MainActivity? // Can be null if app is shutting down
                    } catch (_: ClassCastException) {
                        // Buggy "Z812" phones apparently have the wrong class type for this
                        errormsg("Unexpected class for main activity")
                        null
                    }

                    if (selectedAddress == null && entry.bonded && activity != null)
                        changeScanSelection(
                            activity,
                            fullAddr
                        )
                    addDevice(entry) // Add/replace entry
                }
            }
        }
    }

    private fun addDevice(entry: DeviceListEntry) {
        val oldDevs = devices.value!!
        oldDevs[entry.address] = entry // Add/replace entry
        devices.value = oldDevs // trigger gui updates
    }

    @SuppressLint("MissingPermission")
    fun stopScan() {
        if (scanner != null) {
            debug("stopping scan")
            try {
                scanner?.stopScan(scanCallback)
            } catch (ex: Throwable) {
                warn("Ignoring error stopping scan, probably BT adapter was disabled suddenly: ${ex.message}")
            }
            scanner = null
        }
    }

    /**
     * returns true if we could start scanning, false otherwise
     */
    fun setupScan(): Boolean {
        selectedAddress = RadioInterfaceService.getDeviceAddress(context, usbRepository)

        return if (bluetoothAdapter == null || MockInterface.addressValid(context, usbRepository, "")) {
            warn("No bluetooth adapter.  Running under emulation?")

            val testnodes = listOf(
                DeviceListEntry("Included simulator", "m", true),
                DeviceListEntry("Complete simulator", "t10.0.2.2", true),
                DeviceListEntry(context.getString(R.string.none), "n", true)
                /* Don't populate fake bluetooth devices, because we don't want testlab inside of google
                to try and use them.

                DeviceListEntry("Meshtastic_ab12", "xaa", false),
                DeviceListEntry("Meshtastic_32ac", "xbb", true) */
            )

            devices.value = (testnodes.map { it.address to it }).toMap().toMutableMap()

            // If nothing was selected, by default select the first thing we see
            if (selectedAddress == null)
                changeScanSelection(
                    GeeksvilleApplication.currentActivity as MainActivity,
                    testnodes.first().address
                )

            true
        } else {
            /* model.bluetoothEnabled.value */
            val serialDevices by lazy {
                usbRepository.serialDevicesWithDrivers.value
            }
            if (bluetoothAdapter.bluetoothLeScanner == null && serialDevices.isEmpty()) {
                errorText.value =
                    context.getString(R.string.requires_bluetooth)

                false
            } else {
                if (scanner == null) {

                    // Clear the old device list
                    devices.value?.clear()

                    // Include a placeholder for "None"
                    addDevice(DeviceListEntry(context.getString(R.string.none), "n", true))

                    serialDevices.forEach { (_, d) ->
                        addDevice(USBDeviceListEntry(usbManager, d))
                    }
                } else {
                    debug("scan already running")
                }
                true
            }
        }
    }

    @SuppressLint("MissingPermission")
    fun startScan() {
        /// The following call might return null if the user doesn't have bluetooth access permissions
        val bluetoothLeScanner: BluetoothLeScanner? = bluetoothAdapter?.bluetoothLeScanner

        if (bluetoothLeScanner != null) { // could be null if bluetooth is disabled
            debug("starting scan")

            // filter and only accept devices that have our service
            val filter =
                ScanFilter.Builder()
                    // Samsung doesn't seem to filter properly by service so this can't work
                    // see https://stackoverflow.com/questions/57981986/altbeacon-android-beacon-library-not-working-after-device-has-screen-off-for-a-s/57995960#57995960
                    // and https://stackoverflow.com/a/45590493
                    // .setServiceUuid(ParcelUuid(BluetoothInterface.BTM_SERVICE_UUID))
                    .build()

            val settings =
                ScanSettings.Builder().setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
                    .build()
            bluetoothLeScanner.startScan(listOf(filter), settings, scanCallback)
            scanner = bluetoothLeScanner
        }
    }

    val devices = object : MutableLiveData<MutableMap<String, DeviceListEntry>>(mutableMapOf()) {

        /**
         * Called when the number of active observers change from 1 to 0.
         *
         *
         * This does not mean that there are no observers left, there may still be observers but their
         * lifecycle states aren't [Lifecycle.State.STARTED] or [Lifecycle.State.RESUMED]
         * (like an Activity in the back stack).
         *
         *
         * You can check if there are observers via [.hasObservers].
         */
        override fun onInactive() {
            super.onInactive()
            // stopScan()
        }
    }

    /// Called by the GUI when a new device has been selected by the user
    /// Returns true if we were able to change to that item
    fun onSelected(activity: MainActivity, it: DeviceListEntry): Boolean {
        // If the device is paired, let user select it, otherwise start the pairing flow
        if (it.bonded) {
            changeScanSelection(activity, it.address)
            return true
        } else {
            // Handle requestng USB or bluetooth permissions for the device
            debug("Requesting permissions for the device")

            exceptionReporter {
                val bleAddress = it.bluetoothAddress
                if (bleAddress != null) {
                    // Request bonding for bluetooth
                    // We ignore missing BT adapters, because it lets us run on the emulator
                    bluetoothAdapter
                        ?.getRemoteDevice(bleAddress)?.let { device ->
                            requestBonding(activity, device) { state ->
                                if (state == BOND_BONDED) {
                                    errorText.value = activity.getString(R.string.pairing_completed)
                                    changeScanSelection(
                                        activity,
                                        it.address
                                    )
                                } else {
                                    errorText.value =
                                        activity.getString(R.string.pairing_failed_try_again)
                                }

                                // Force the GUI to redraw
                                devices.value = devices.value
                            }
                        }
                }
            }

            if (it.isSerial) {
                it as USBDeviceListEntry

                val ACTION_USB_PERMISSION = "com.geeksville.mesh.USB_PERMISSION"

                val usbReceiver = object : BroadcastReceiver() {

                    override fun onReceive(context: Context, intent: Intent) {
                        if (ACTION_USB_PERMISSION == intent.action) {

                            val device: UsbDevice =
                                intent.getParcelableExtra(UsbManager.EXTRA_DEVICE)!!

                            if (intent.getBooleanExtra(
                                    UsbManager.EXTRA_PERMISSION_GRANTED,
                                    false
                                )
                            ) {
                                info("User approved USB access")
                                changeScanSelection(activity, it.address)

                                // Force the GUI to redraw
                                devices.value = devices.value
                            } else {
                                errormsg("USB permission denied for device $device")
                            }
                        }
                        // We don't need to stay registered
                        activity.unregisterReceiver(this)
                    }
                }

                val permissionIntent =
                    PendingIntent.getBroadcast(activity, 0, Intent(ACTION_USB_PERMISSION), 0)
                val filter = IntentFilter(ACTION_USB_PERMISSION)
                activity.registerReceiver(usbReceiver, filter)
                usbManager.requestPermission(it.usb.device, permissionIntent)
            }

            return false
        }
    }

    /// Change to a new macaddr selection, updating GUI and radio
    fun changeScanSelection(context: MainActivity, newAddr: String) {
        try {
            info("Changing device to ${newAddr.anonymize}")
            changeDeviceSelection(context, newAddr)
            selectedAddress =
                newAddr // do this after changeDeviceSelection, so if it throws the change will be discarded
            devices.value = devices.value // Force a GUI update
        } catch (ex: RemoteException) {
            errormsg("Failed talking to service, probably it is shutting down $ex.message")
            // ignore the failure and the GUI won't be updating anyways
        }
    }
}

@SuppressLint("NewApi")
@AndroidEntryPoint
class SettingsFragment : ScreenFragment("Settings"), Logging {
    private var _binding: SettingsFragmentBinding? = null

    // This property is only valid between onCreateView and onDestroyView.
    private val binding get() = _binding!!

    private val scanModel: BTScanModel by activityViewModels()
    private val bluetoothViewModel: BluetoothViewModel by activityViewModels()
    private val model: UIViewModel by activityViewModels()

    // FIXME - move this into a standard GUI helper class
    private val guiJob = Job()

    @Inject
    internal lateinit var usbRepository: UsbRepository

    private val hasCompanionDeviceApi: Boolean by lazy {
        BluetoothInterface.hasCompanionDeviceApi(requireContext())
    }

    private val deviceManager: CompanionDeviceManager by lazy {
        requireContext().getSystemService(Context.COMPANION_DEVICE_SERVICE) as CompanionDeviceManager
    }

    private val myActivity get() = requireActivity() as MainActivity

    override fun onDestroy() {
        guiJob.cancel()
        super.onDestroy()
    }

    private fun doFirmwareUpdate() {
        model.meshService?.let { service ->

            debug("User started firmware update")
            GeeksvilleApplication.analytics.track(
                "firmware_update",
                DataPair("content_type", "start")
            )
            binding.updateFirmwareButton.isEnabled = false // Disable until things complete
            binding.updateProgressBar.visibility = View.VISIBLE
            binding.updateProgressBar.progress = 0 // start from scratch

            exceptionToSnackbar(requireView()) {
                // We rely on our broadcast receiver to show progress as this progresses
                service.startFirmwareUpdate()
            }
        }
    }

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        _binding = SettingsFragmentBinding.inflate(inflater, container, false)
        return binding.root
    }

    /// Set the correct update button configuration based on current progress
    private fun refreshUpdateButton(enable: Boolean) {
        debug("Reiniting the update button")
        val info = model.myNodeInfo.value
        val service = model.meshService
        if (model.isConnected() && info != null && info.shouldUpdate && info.couldUpdate && service != null) {
            binding.updateFirmwareButton.visibility = View.VISIBLE
            binding.updateFirmwareButton.text =
                getString(R.string.update_to).format(getString(R.string.short_firmware_version))

            val progress = service.updateStatus

            binding.updateFirmwareButton.isEnabled = enable &&
                (progress < 0) // if currently doing an upgrade disable button

            if (progress >= 0) {
                binding.updateProgressBar.progress = progress // update partial progress
                binding.scanStatusText.setText(R.string.updating_firmware)
                binding.updateProgressBar.visibility = View.VISIBLE
            } else
                when (progress) {
                    ProgressSuccess -> {
                        GeeksvilleApplication.analytics.track(
                            "firmware_update",
                            DataPair("content_type", "success")
                        )
                        binding.scanStatusText.setText(R.string.update_successful)
                        binding.updateProgressBar.visibility = View.GONE
                    }
                    ProgressNotStarted -> {
                        // Do nothing - because we don't want to overwrite the status text in this case
                        binding.updateProgressBar.visibility = View.GONE
                    }
                    else -> {
                        GeeksvilleApplication.analytics.track(
                            "firmware_update",
                            DataPair("content_type", "failure")
                        )
                        binding.scanStatusText.setText(R.string.update_failed)
                        binding.updateProgressBar.visibility = View.VISIBLE
                    }
                }
            binding.updateProgressBar.isEnabled = false

        } else {
            binding.updateFirmwareButton.visibility = View.GONE
            binding.updateProgressBar.visibility = View.GONE
        }
    }

    /**
     * Pull the latest device info from the model and into the GUI
     */
    private fun updateNodeInfo() {
        val connected = model.connectionState.value

        val isConnected = connected == MeshService.ConnectionState.CONNECTED
        binding.nodeSettings.visibility = if (isConnected) View.VISIBLE else View.GONE
        binding.provideLocationCheckbox.visibility = if (isConnected) View.VISIBLE else View.GONE

        if (connected == MeshService.ConnectionState.DISCONNECTED)
            model.setOwner("")

        // update the region selection from the device
        val region = model.region
        val spinner = binding.regionSpinner
        val unsetIndex = regions.indexOf(RadioConfigProtos.RegionCode.Unset.name)
        spinner.onItemSelectedListener = null

        debug("current region is $region")
        var regionIndex = regions.indexOf(region.name)
        if (regionIndex == -1) // Not found, probably because the device has a region our app doesn't yet understand.  Punt and say Unset
            regionIndex = unsetIndex

        // We don't want to be notified of our own changes, so turn off listener while making them
        spinner.setSelection(regionIndex, false)
        spinner.onItemSelectedListener = regionSpinnerListener
        spinner.isEnabled = true

        // If actively connected possibly let the user update firmware
        refreshUpdateButton(region != RadioConfigProtos.RegionCode.Unset)

        // Update the status string (highest priority messages first)
        val info = model.myNodeInfo.value
        val statusText = binding.scanStatusText
        val permissionsWarning = myActivity.getMissingMessage()
        when {
            (permissionsWarning != null) ->
                statusText.text = permissionsWarning

            region == RadioConfigProtos.RegionCode.Unset ->
                statusText.text = getString(R.string.must_set_region)

            connected == MeshService.ConnectionState.CONNECTED -> {
                val fwStr = info?.firmwareString ?: "unknown"
                statusText.text = getString(R.string.connected_to).format(fwStr)
            }
            connected == MeshService.ConnectionState.DISCONNECTED ->
                statusText.text = getString(R.string.not_connected)
            connected == MeshService.ConnectionState.DEVICE_SLEEP ->
                statusText.text = getString(R.string.connected_sleeping)
        }
    }

    private val regionSpinnerListener = object : AdapterView.OnItemSelectedListener {
        override fun onItemSelected(
            parent: AdapterView<*>,
            view: View,
            position: Int,
            id: Long
        ) {
            val item = parent.getItemAtPosition(position) as String?
            val asProto = item!!.let { RadioConfigProtos.RegionCode.valueOf(it) }
            exceptionToSnackbar(requireView()) {
                model.region = asProto
            }
            updateNodeInfo() // We might have just changed Unset to set
        }

        override fun onNothingSelected(parent: AdapterView<*>) {
            //TODO("Not yet implemented")
        }
    }

    /// the sorted list of region names like arrayOf("US", "CN", "EU488")
    private val regions = RadioConfigProtos.RegionCode.values().filter {
        it != RadioConfigProtos.RegionCode.UNRECOGNIZED
    }.map {
        it.name
    }.sorted()

    private fun initCommonUI() {
        scanModel.setupScan()

        // init our region spinner
        val spinner = binding.regionSpinner
        val regionAdapter =
            ArrayAdapter(requireContext(), android.R.layout.simple_spinner_item, regions)
        regionAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)
        spinner.adapter = regionAdapter

        bluetoothViewModel.enabled.observe(viewLifecycleOwner) {
            if (it) binding.changeRadioButton.show()
            else binding.changeRadioButton.hide()
        }

        model.ownerName.observe(viewLifecycleOwner) { name ->
            binding.usernameEditText.setText(name)
        }

        // Only let user edit their name or set software update while connected to a radio
        model.connectionState.observe(viewLifecycleOwner) {
            updateNodeInfo()
            updateDevicesButtons(scanModel.devices.value)
        }

        model.radioConfig.observe(viewLifecycleOwner) {
            binding.provideLocationCheckbox.isEnabled =
                isGooglePlayAvailable(requireContext()) && !model.locationShareDisabled
            if (model.locationShareDisabled) {
                model.provideLocation.value = false
                binding.provideLocationCheckbox.isChecked = false
            }
        }

        // Also watch myNodeInfo because it might change later
        model.myNodeInfo.observe(viewLifecycleOwner) {
            updateNodeInfo()
        }

        scanModel.devices.observe(viewLifecycleOwner) { devices ->
            updateDevicesButtons(devices)
        }

        scanModel.errorText.observe(viewLifecycleOwner) { errMsg ->
            if (errMsg != null) {
                binding.scanStatusText.text = errMsg
            }
        }

        binding.updateFirmwareButton.setOnClickListener {
            MaterialAlertDialogBuilder(requireContext())
                .setMessage("${getString(R.string.update_firmware)}?")
                .setNeutralButton(R.string.cancel) { _, _ ->
                }
                .setPositiveButton(getString(R.string.okay)) { _, _ ->
                    doFirmwareUpdate()
                }
                .show()
        }

        binding.usernameEditText.on(EditorInfo.IME_ACTION_DONE) {
            debug("did IME action")
            val n = binding.usernameEditText.text.toString().trim()
            if (n.isNotEmpty())
                model.setOwner(n)
            requireActivity().hideKeyboard()
        }

        binding.provideLocationCheckbox.setOnCheckedChangeListener { view, isChecked ->
            if (view.isPressed && isChecked) { // We want to ignore changes caused by code (as opposed to the user)
                // Don't check the box until the system setting changes
                view.isChecked = myActivity.hasLocationPermission() && myActivity.hasBackgroundPermission()

                if (!myActivity.hasLocationPermission()) // Make sure we have location permission (prerequisite)
                    myActivity.requestLocationPermission()
                else if (!myActivity.hasBackgroundPermission())
                    MaterialAlertDialogBuilder(requireContext())
                        .setTitle(R.string.background_required)
                        .setMessage(R.string.why_background_required)
                        .setNeutralButton(R.string.cancel) { _, _ ->
                            debug("User denied background permission")
                        }
                        .setPositiveButton(getString(R.string.accept)) { _, _ ->
                            myActivity.requestBackgroundPermission()
                        }
                        .show()
                if (view.isChecked) {
                    debug("User changed location tracking to $isChecked")
                    model.provideLocation.value = isChecked
                    checkLocationEnabled(getString(R.string.location_disabled))
                    model.meshService?.setupProvideLocation()
                }
            } else {
                model.provideLocation.value = isChecked
                model.meshService?.stopProvideLocation()
            }
        }

        val app = (requireContext().applicationContext as GeeksvilleApplication)

        // Set analytics checkbox
        binding.analyticsOkayCheckbox.isChecked = app.isAnalyticsAllowed

        binding.analyticsOkayCheckbox.setOnCheckedChangeListener { _, isChecked ->
            debug("User changed analytics to $isChecked")
            app.isAnalyticsAllowed = isChecked
            binding.reportBugButton.isEnabled = app.isAnalyticsAllowed
        }

        // report bug button only enabled if analytics is allowed
        binding.reportBugButton.isEnabled = app.isAnalyticsAllowed
        binding.reportBugButton.setOnClickListener {
            MaterialAlertDialogBuilder(requireContext())
                .setTitle(R.string.report_a_bug)
                .setMessage(getString(R.string.report_bug_text))
                .setNeutralButton(R.string.cancel) { _, _ ->
                    debug("Decided not to report a bug")
                }
                .setPositiveButton(getString(R.string.report)) { _, _ ->
                    reportError("Clicked Report A Bug")
                    Toast.makeText(requireContext(), "Bug report sent!", Toast.LENGTH_LONG).show()
                }
                .show()
        }
    }

    private fun addDeviceButton(device: BTScanModel.DeviceListEntry, enabled: Boolean) {
        val b = RadioButton(requireActivity())
        b.text = device.name
        b.id = View.generateViewId()
        b.isEnabled = enabled
        b.isChecked =
            device.address == scanModel.selectedNotNull && device.bonded // Only show checkbox if device is still paired
        binding.deviceRadioGroup.addView(b)

        b.setOnClickListener {
            if (!device.bonded) // If user just clicked on us, try to bond
                binding.scanStatusText.setText(R.string.starting_pairing)

            b.isChecked =
                scanModel.onSelected(myActivity, device)

            if (!b.isSelected) {
                binding.scanStatusText.text = getString(R.string.please_pair)
            }
        }
    }

    @SuppressLint("MissingPermission")
    private fun updateDevicesButtons(devices: MutableMap<String, BTScanModel.DeviceListEntry>?) {
        // Remove the old radio buttons and repopulate
        binding.deviceRadioGroup.removeAllViews()

        if (devices == null) return

        val adapter = scanModel.bluetoothAdapter
        var hasShownOurDevice = false
        devices.values.forEach { device ->
            if (device.address == scanModel.selectedNotNull)
                hasShownOurDevice = true
            addDeviceButton(device, true)
        }

        // The selected device is not in the scan; it is either offline, or it doesn't advertise
        // itself (most BLE devices don't advertise when connected).
        // Show it in the list, greyed out based on connection status.
        if (!hasShownOurDevice) {
            // Note: we pull this into a tempvar, because otherwise some other thread can change selectedAddress after our null check
            // and before use
            val bleAddr = scanModel.selectedBluetooth

            if (bleAddr != null && adapter != null && myActivity.hasConnectPermission()) {
                val bDevice =
                    adapter.getRemoteDevice(bleAddr)
                if (bDevice.name != null) { // ignore nodes that node have a name, that means we've lost them since they appeared
                    val curDevice = BTScanModel.DeviceListEntry(
                        bDevice.name,
                        scanModel.selectedAddress!!,
                        bDevice.bondState == BOND_BONDED
                    )
                    addDeviceButton(
                        curDevice,
                        model.isConnected()
                    )
                }
            } else if (scanModel.selectedUSB != null) {
                // Must be a USB device, show a placeholder disabled entry
                val curDevice = BTScanModel.DeviceListEntry(
                    scanModel.selectedUSB!!,
                    scanModel.selectedAddress!!,
                    false
                )
                addDeviceButton(curDevice, false)
            }
        }

        // get rid of the warning text once at least one device is paired.
        // If we are running on an emulator, always leave this message showing so we can test the worst case layout
        val curRadio = RadioInterfaceService.getBondedDeviceAddress(requireContext(), usbRepository)

        if (curRadio != null && !MockInterface.addressValid(requireContext(), usbRepository, "")) {
            binding.warningNotPaired.visibility = View.GONE
            // binding.scanStatusText.text = getString(R.string.current_pair).format(curRadio)
        } else if (bluetoothViewModel.enabled.value == true){
            binding.warningNotPaired.visibility = View.VISIBLE
            binding.scanStatusText.text = getString(R.string.not_paired_yet)
        }
    }

    private fun initClassicScan() {

        binding.changeRadioButton.setOnClickListener {
            debug("User clicked changeRadioButton")
            if (!myActivity.hasScanPermission()) {
                myActivity.requestScanPermission()
            } else {
                checkLocationEnabled()
                scanLeDevice()
            }
        }
    }

    // per https://developer.android.com/guide/topics/connectivity/bluetooth/find-ble-devices
    private fun scanLeDevice() {
        var scanning = false
        val SCAN_PERIOD: Long = 5000 // Stops scanning after 5 seconds

        if (!scanning) { // Stops scanning after a pre-defined scan period.
            Handler(Looper.getMainLooper()).postDelayed({
                scanning = false
                binding.scanProgressBar.visibility = View.GONE
                scanModel.stopScan()
            }, SCAN_PERIOD)
            scanning = true
            binding.scanProgressBar.visibility = View.VISIBLE
            scanModel.startScan()
        } else {
            scanning = false
            binding.scanProgressBar.visibility = View.GONE
            scanModel.stopScan()
        }
    }

    private fun associationRequest(): AssociationRequest {
        // To skip filtering based on name and supported feature flags (UUIDs),
        // don't include calls to setNamePattern() and addServiceUuid(),
        // respectively. This example uses Bluetooth.
        // We only look for Mesh (rather than the full name) because NRF52 uses a very short name
        val deviceFilter: BluetoothDeviceFilter = BluetoothDeviceFilter.Builder()
            .setNamePattern(Pattern.compile("Mesh.*"))
            // .addServiceUuid(ParcelUuid(RadioInterfaceService.BTM_SERVICE_UUID), null)
            .build()

        // The argument provided in setSingleDevice() determines whether a single
        // device name or a list of device names is presented to the user as
        // pairing options.
        return AssociationRequest.Builder()
            .addDeviceFilter(deviceFilter)
            .setSingleDevice(false)
            .build()
    }

    @SuppressLint("MissingPermission")
    val associationResultLauncher = registerForActivityResult(
        ActivityResultContracts.StartIntentSenderForResult()
    ) {
        it.data
            ?.getParcelableExtra<BluetoothDevice>(CompanionDeviceManager.EXTRA_DEVICE)
            ?.let { device ->
                scanModel.onSelected(
                    myActivity,
                    BTScanModel.DeviceListEntry(
                        device.name,
                        "x${device.address}",
                        device.bondState == BOND_BONDED
                    )
                )
            }
    }

    private fun startCompanionScan() {
        // Disable the change button until our scan has some results
        binding.changeRadioButton.isEnabled = false

        // When the app tries to pair with the Bluetooth device, show the
        // appropriate pairing request dialog to the user.
        deviceManager.associate(
            associationRequest(),
            object : CompanionDeviceManager.Callback() {
                override fun onDeviceFound(chooserLauncher: IntentSender) {
                    debug("Found one device - enabling changeRadioButton")
                    binding.changeRadioButton.isEnabled = true
                    binding.changeRadioButton.setOnClickListener {
                        chooserLauncher.let {
                            val request = IntentSenderRequest.Builder(it).build()
                            associationResultLauncher.launch(request)
                        }
                    }
                }

                override fun onFailure(error: CharSequence?) {
                    warn("BLE selection service failed $error")
                    // changeDeviceSelection(myActivity, null) // deselect any device
                }
            }, null
        )
    }

    private fun initModernScan() {

        scanModel.devices.observe(viewLifecycleOwner) {
            startCompanionScan()
        }
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        initCommonUI()
        if (hasCompanionDeviceApi)
            initModernScan()
        else
            initClassicScan()
    }

    // If the user has not turned on location access throw up a toast warning
    private fun checkLocationEnabled(
        warningReason: String = getString(R.string.location_disabled_warning)
    ) {

        val hasGps: Boolean =
            myActivity.packageManager.hasSystemFeature(PackageManager.FEATURE_LOCATION_GPS)

        // FIXME If they don't have google play for now we don't check for location enabled
        if (hasGps && isGooglePlayAvailable(requireContext())) {
            // We do this painful process because LocationManager.isEnabled is only SDK28 or latet
            val builder = LocationSettingsRequest.Builder()
            builder.setNeedBle(true)

            val request = LocationRequest.create().apply {
                priority = LocationRequest.PRIORITY_HIGH_ACCURACY
            }
            builder.addLocationRequest(request) // Make sure we are granted high accuracy permission

            val locationSettingsResponse = LocationServices.getSettingsClient(requireActivity())
                .checkLocationSettings(builder.build())

            fun weNeedAccess(warningReason: String) {
                warn("Telling user we need need location access")
                showSnackbar(warningReason)
            }

            locationSettingsResponse.addOnSuccessListener {
                if (!it.locationSettingsStates?.isBleUsable!! || !it.locationSettingsStates?.isLocationUsable!!)
                    weNeedAccess(warningReason)
                else
                    debug("We have location access")
            }

            locationSettingsResponse.addOnFailureListener {
                errormsg("Failed to get location access")
                // We always show the toast regardless of what type of exception we receive.  Because even non
                // resolvable api exceptions mean user still needs to fix something.

                ///if (exception is ResolvableApiException) {

                // Location settings are not satisfied, but this can be fixed
                // by showing the user a dialog.

                // Show the dialog by calling startResolutionForResult(),
                // and check the result in onActivityResult().
                // exception.startResolutionForResult(this@MainActivity, REQUEST_CHECK_SETTINGS)

                // For now just punt and show a dialog

                // The context might be gone (if activity is going away) by the time this handler is called
                weNeedAccess(warningReason)

                //} else
                //    Exceptions.report(exception)
            }
        }
    }

    private val updateProgressFilter = IntentFilter(ACTION_UPDATE_PROGRESS)

    private val updateProgressReceiver: BroadcastReceiver = object : BroadcastReceiver() {
        override fun onReceive(context: Context?, intent: Intent?) {
            refreshUpdateButton(true)
        }
    }

    private fun showSnackbar(msg: String) {
        try {
            Snackbar.make(
                requireView(),
                msg,
                Snackbar.LENGTH_INDEFINITE
            )
                .apply { view.findViewById<TextView>(R.id.snackbar_text).isSingleLine = false }
                .setAction(R.string.okay) {
                    // dismiss
                }
                .show()
        } catch (ex: IllegalStateException) {
            errormsg("Snackbar couldn't find view for msgString $msg")
        }
    }

    override fun onPause() {
        super.onPause()

        requireActivity().unregisterReceiver(updateProgressReceiver)
    }

    override fun onResume() {
        super.onResume()

        scanModel.setupScan()

        // system permissions might have changed while we were away
        binding.provideLocationCheckbox.isChecked = myActivity.hasLocationPermission() && myActivity.hasBackgroundPermission() && (model.provideLocation.value ?: false) && isGooglePlayAvailable(requireContext())

        myActivity.registerReceiver(updateProgressReceiver, updateProgressFilter)

        // Keep reminding user BLE is still off
        val hasUSB = usbRepository.serialDevicesWithDrivers.value.isNotEmpty()
        if (!hasUSB) {
            // Warn user if BLE is disabled
            if (scanModel.bluetoothAdapter?.isEnabled != true) {
                showSnackbar(getString(R.string.error_bluetooth))
            } else {
                if (binding.provideLocationCheckbox.isChecked)
                    checkLocationEnabled(getString(R.string.location_disabled))
            }
        }
    }
}