package my.package

import android.app.Application
import android.app.NotificationChannel
import android.app.NotificationManager
import android.os.Build
import androidx.core.app.NotificationManagerCompat
import my.package.ble.DaemonConfig
import my.package.ble.NotificationHelper.SERVICE_CHANNEL_ID
import my.package.ble.ScannerManager

class MainApplication : Application() {
    override fun onCreate() {
        super.onCreate()

        // delegated to a ble component, to keep the pure app module clean of direct accesses to the library
        ScannerManager.init(this)

        DaemonConfig.init(this, EventListener(this), MainActivity::class.java)

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            // create a notification channel, mandatory for the Foreground Service
            val notificationManager = NotificationManagerCompat.from(this)
            val serviceChannel = NotificationChannel(
                SERVICE_CHANNEL_ID,
                "Bluetooth beacon listening service in background",
                NotificationManager.IMPORTANCE_LOW // "no sound"
            )
            serviceChannel.description = "Locates nearby beacons" // optional
            notificationManager.createNotificationChannel(serviceChannel)
        }
    }
}

package my.package

import android.os.Bundle
import android.util.Log
import androidx.activity.ComponentActivity
import my.package.ble.Configuration
import my.package.ble.IStatusCallback
import my.package.ble.ScannerManager

class MainActivity : ComponentActivity() {
    // actions are delegated to a component
    private lateinit var mScannerManager: ScannerManager

    override fun onCreate(savedInstanceState: Bundle?) {
        if (BuildConfig.DEBUG) Log.d(TAG, "lifecycle onCreate")
        super.onCreate(savedInstanceState)

        mScannerManager = ScannerManager(this)

        // ... (UI) setup your screen layout
        // typically, for this sample, with start and stop buttons to act on the scanning,
        // respectively associated with onClickSetup() and onClickTeardown()
    }

    override fun onResume() {
        if (BuildConfig.DEBUG) Log.d(TAG, "lifecycle onResume")
        super.onResume()
        mScannerManager.requestScanStatus(mStatusCallback)
    }

    private val mStatusCallback = object : IStatusCallback {
        override fun onResult(isScanning: Boolean) {
            if (BuildConfig.DEBUG) Log.d(TAG, "onResult: isScanning $isScanning")
            // ... (UI) may need to update some elements, like button properties (text, enabled, ...)
        }

        override fun onError(message: String) {
            if (BuildConfig.DEBUG) Log.d(TAG, "onError $message")
            // ... (UI) inform of the failure
        }
    }

    private fun onClickSetup() {
        Log.i(TAG, "onClickSetUp")
        if (mScannerManager.isBluetoothDisabled) {
            // ... (UI) inform that the app can't work at all if the Bluetooth is off
        } else {
            if (mScannerManager.isLocationDisabled) {
                // ... (UI) inform that no detection will be accessible until Location is enabled
                return // useless to insist
            }
            // ... (UI) according to a CheckBox, may set Configuration.instance.preventDoze = true
            // ... (UI) according to a CheckBox, may set Configuration.instance.verbose = true
            mScannerManager.setUp(mStatusCallback)
        }
    }

    private fun onClickTeardown() {
        Log.i((TAG, "onClickTearDown")
        mScannerManager.tearDown(mStatusCallback)
    }

    private companion object {
        private val TAG = MainActivity::class.java.simpleName
    }
}

package my.package

import android.content.Context
import my.package.ble.IEventListener

internal class EventListener(private val mContext: Context) : IEventListener {
    override fun onEvent(line: String) {
        // TODO implement your custom event persistence.
        // For instance, append the line on a local file and schedule a periodic upload to a central backend.
    }
}

package my.package.ble

import android.app.Activity
import android.app.Notification
import android.app.PendingIntent
import android.content.Context
import android.content.Intent
import androidx.core.app.NotificationCompat
import my.package.R

object NotificationHelper {
    const val SERVICE_CHANNEL_ID = "ServiceChanId"
    const val SERVICE_NOTIFICATION_ID = 1

    fun createNotification(context: Context, activityClass: Class<out Activity?>, isLocationDisabled: Boolean): Notification {
        val notificationBuilder = NotificationCompat.Builder(context, SERVICE_CHANNEL_ID)
        val pendingIntent = PendingIntent.getActivity(
            context,
            0,  // "Private request code for the sender", not used
            Intent(context, activityClass).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK),
            PendingIntent.FLAG_IMMUTABLE
        )
        val icon = if (isLocationDisabled) R.drawable.ic_notification_no_result else R.drawable.ic_notification // TODO design your icons
        if (isLocationDisabled) {
            val txt = """
                Location is not currently enabled on your device. Without it, Bluetooth will not deliver beacon detections to the observer.
                Tap to open the app
                """.trimIndent()
            notificationBuilder.setStyle(NotificationCompat.BigTextStyle().bigText(txt))
        }
        return notificationBuilder
            .setSmallIcon(icon)
            .setContentTitle("App launched in background")  // TODO set your title
            .setContentText(if (isLocationDisabled) "Defect: geolocation is missing ..." else "Tap to open the app.")
            .setContentIntent(pendingIntent)
            .build()
    }
}

package my.package.ble

interface IStatusCallback {
    fun onResult(isScanning: Boolean)
    fun onError(message: String)
}

package my.package.ble

interface IEventListener {
    fun onEvent(line: String)
}