package de.wechselbild.wallpaper

import android.app.NotificationChannel
import android.app.NotificationManager
import android.app.PendingIntent
import android.app.Service
import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.content.IntentFilter
import android.os.Build
import android.os.IBinder
import androidx.core.app.NotificationCompat
import androidx.core.content.ContextCompat
import java.util.concurrent.Executors
import java.util.concurrent.atomic.AtomicBoolean

class ScreenOnRotationService : Service() {
  private val worker = Executors.newSingleThreadExecutor()
  private val rotating = AtomicBoolean(false)
  private val changedWhileScreenOff = AtomicBoolean(false)
  private val screenReceiver = object : BroadcastReceiver() {
    override fun onReceive(context: Context, intent: Intent) {
      if (!WallpaperStore.screenOnEnabled(context)) return
      when (intent.action) {
        Intent.ACTION_SCREEN_OFF -> rotate(context, preparedForScreenOn = true)
        Intent.ACTION_SCREEN_ON -> {
          if (!changedWhileScreenOff.getAndSet(false)) rotate(context, preparedForScreenOn = false)
        }
      }
    }
  }

  private fun rotate(context: Context, preparedForScreenOn: Boolean) {
    if (!rotating.compareAndSet(false, true)) return
    worker.execute {
      try {
        if (WallpaperStore.applyNext(context, automatic = true) && preparedForScreenOn) {
          changedWhileScreenOff.set(true)
        }
      } finally { rotating.set(false) }
    }
  }

  override fun onCreate() {
    super.onCreate()
    createChannel()
    val launch = packageManager.getLaunchIntentForPackage(packageName)
    val pending = PendingIntent.getActivity(this, 0, launch, PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT)
    val notification = NotificationCompat.Builder(this, CHANNEL)
      .setSmallIcon(android.R.drawable.ic_menu_gallery)
      .setContentTitle(getString(R.string.wallpaper_service_title))
      .setContentText(getString(R.string.wallpaper_service_text))
      .setOngoing(true)
      .setSilent(true)
      .setContentIntent(pending)
      .build()
    startForeground(NOTIFICATION_ID, notification)
    val filter = IntentFilter().apply {
      addAction(Intent.ACTION_SCREEN_OFF)
      addAction(Intent.ACTION_SCREEN_ON)
    }
    if (Build.VERSION.SDK_INT >= 33) {
      registerReceiver(screenReceiver, filter, Context.RECEIVER_NOT_EXPORTED)
    } else {
      @Suppress("DEPRECATION")
      registerReceiver(screenReceiver, filter)
    }
  }

  override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
    if (!WallpaperStore.screenOnEnabled(this)) {
      stopSelf()
      return START_NOT_STICKY
    }
    return START_STICKY
  }

  override fun onBind(intent: Intent?): IBinder? = null

  override fun onDestroy() {
    runCatching { unregisterReceiver(screenReceiver) }
    worker.shutdown()
    super.onDestroy()
  }

  companion object {
    private const val CHANNEL = "wechselbild_screen_on"
    private const val NOTIFICATION_ID = 4217

    fun start(context: Context) {
      ContextCompat.startForegroundService(context, Intent(context, ScreenOnRotationService::class.java))
    }

    fun stop(context: Context) {
      context.stopService(Intent(context, ScreenOnRotationService::class.java))
    }
  }

  private fun createChannel() {
    if (Build.VERSION.SDK_INT >= 26) {
      val channel = NotificationChannel(CHANNEL, getString(R.string.wallpaper_channel_name), NotificationManager.IMPORTANCE_LOW)
      getSystemService(NotificationManager::class.java).createNotificationChannel(channel)
    }
  }
}