Fix DownloadService leak

app/src/main/java/org/koitharu/kotatsu/download/ui/service/DownloadService.kt

@@ -9,6 +9,8 @@ import android.os.IBinder
 import android.os.PowerManager
 import android.widget.Toast
 import androidx.core.content.ContextCompat
+import androidx.lifecycle.DefaultLifecycleObserver
+import androidx.lifecycle.LifecycleOwner
 import androidx.lifecycle.lifecycleScope
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import java.util.concurrent.TimeUnit
@@ -41,7 +43,6 @@ class DownloadService : BaseService() {
 	private val jobs = LinkedHashMap<Int, PausingProgressJob<DownloadState>>()
 	private val jobCount = MutableStateFlow(0)
 	private val controlReceiver = ControlReceiver()
-	private var binder: DownloadBinder? = null
 
 	override fun onCreate() {
 		super.onCreate()
@@ -50,7 +51,7 @@ class DownloadService : BaseService() {
 		val wakeLock = (getSystemService(Context.POWER_SERVICE) as PowerManager)
 			.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "kotatsu:downloading")
 		downloadManager = get<DownloadManager.Factory>().create(
-			coroutineScope = lifecycleScope + WakeLockNode(wakeLock, TimeUnit.HOURS.toMillis(1))
+			coroutineScope = lifecycleScope + WakeLockNode(wakeLock, TimeUnit.HOURS.toMillis(1)),
 		)
 		DownloadNotification.createChannel(this)
 		val intentFilter = IntentFilter()
@@ -75,17 +76,11 @@ class DownloadService : BaseService() {
 
 	override fun onBind(intent: Intent): IBinder {
 		super.onBind(intent)
-		return binder ?: DownloadBinder(this).also { binder = it }
-	}
-
-	override fun onUnbind(intent: Intent?): Boolean {
-		binder = null
-		return super.onUnbind(intent)
+		return DownloadBinder(this)
 	}
 
 	override fun onDestroy() {
 		unregisterReceiver(controlReceiver)
-		binder = null
 		isRunning = false
 		super.onDestroy()
 	}
@@ -126,7 +121,7 @@ class DownloadService : BaseService() {
 				(job.progressValue as? DownloadState.Done)?.let {
 					sendBroadcast(
 						Intent(ACTION_DOWNLOAD_COMPLETE)
-							.putExtra(EXTRA_MANGA, ParcelableManga(it.localManga, withChapters = false))
+							.putExtra(EXTRA_MANGA, ParcelableManga(it.localManga, withChapters = false)),
 					)
 				}
 				notificationSwitcher.detach(
@@ -135,7 +130,7 @@ class DownloadService : BaseService() {
 						null
 					} else {
 						notification.create(job.progressValue, -1L)
-					}
+					},
 				)
 				stopSelf(startId)
 			}
@@ -167,10 +162,25 @@ class DownloadService : BaseService() {
 		}
 	}
 
-	class DownloadBinder(private val service: DownloadService) : Binder() {
+	class DownloadBinder(service: DownloadService) : Binder(), DefaultLifecycleObserver {
 
-		val downloads: Flow<Collection<ProgressJob<DownloadState>>>
-			get() = service.jobCount.mapLatest { service.jobs.values }
+		private var downloadsStateFlow = MutableStateFlow<Collection<PausingProgressJob<DownloadState>>>(emptyList())
+
+		init {
+			service.lifecycle.addObserver(this)
+			service.jobCount.onEach {
+				downloadsStateFlow.value = service.jobs.values
+			}.launchIn(service.lifecycleScope)
+		}
+
+		override fun onDestroy(owner: LifecycleOwner) {
+			owner.lifecycle.removeObserver(this)
+			downloadsStateFlow.value = emptyList()
+			super.onDestroy(owner)
+		}
+
+		val downloads
+			get() = downloadsStateFlow.asStateFlow()
 	}
 
 	companion object {