address review: keep notification taps working after recreation

app/src/main/kotlin/com/subtracks/MainActivity.kt

@@ -24,7 +24,9 @@ class MainActivity : ComponentActivity() {
         super.onCreate(savedInstanceState)
         requestNotificationPermission()
         enableEdgeToEdge()
-        if (intent?.action == ACTION_OPEN_NOW_PLAYING) nowPlayingRequest.intValue++
+        if (shouldRecordNowPlayingLaunch(intent?.action, restoringState = savedInstanceState != null)) {
+            nowPlayingRequest.intValue++
+        }
         setContent {
             SubtracksTheme {
                 SubtracksRoot(nowPlayingRequest = nowPlayingRequest.intValue)
@@ -50,3 +52,8 @@ class MainActivity : ComponentActivity() {
         const val ACTION_OPEN_NOW_PLAYING = "com.subtracks.action.OPEN_NOW_PLAYING"
     }
 }
+
+internal fun shouldRecordNowPlayingLaunch(
+    action: String?,
+    restoringState: Boolean,
+): Boolean = action == MainActivity.ACTION_OPEN_NOW_PLAYING && !restoringState

app/src/main/kotlin/com/subtracks/ui/AppRoot.kt

@@ -166,12 +166,6 @@ internal fun resetOnSourceSwitch(
     if (route in DETAIL_ROUTES) popDetail()
 }
 
-internal fun shouldOpenNowPlaying(
-    request: Int,
-    handled: Int,
-    playerVisible: Boolean,
-): Boolean = playerVisible && request > handled
-
 internal data class BackStackKey(
     val route: String?,
     val argument: String?,
@@ -227,7 +221,7 @@ private fun MainNavigation(nowPlayingRequest: Int) {
     val downloads by downloadRepository.states().collectAsStateWithLifecycle()
     var showingQueue by rememberSaveable { mutableStateOf(false) }
     var nowPlayingOpen by rememberSaveable { mutableStateOf(false) }
-    var handledNowPlayingRequest by rememberSaveable { mutableStateOf(0) }
+    var handledNowPlayingRequest by remember { mutableStateOf(0) }
     var nowPlayingProgress by remember { mutableFloatStateOf(0f) }
     var miniPlayerTopPx by remember { mutableFloatStateOf(0f) }
     var nowPlayingFadeOut by remember { mutableStateOf(false) }
@@ -313,8 +307,11 @@ private fun MainNavigation(nowPlayingRequest: Int) {
         }
     }
     LaunchedEffect(nowPlayingRequest, playerVisible) {
-        if (shouldOpenNowPlaying(nowPlayingRequest, handledNowPlayingRequest, playerVisible)) {
+        if (playerVisible && nowPlayingRequest > handledNowPlayingRequest) {
             handledNowPlayingRequest = nowPlayingRequest
+            if (navController.currentDestination?.route in DETAIL_ROUTES) {
+                navController.popBackStack(Routes.LIBRARY, inclusive = false)
+            }
             settleNowPlaying(true)
         }
     }

app/src/test/kotlin/com/subtracks/NowPlayingLaunchTest.kt

@@ -0,0 +1,37 @@
+package com.subtracks
+
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class NowPlayingLaunchTest {
+    @Test
+    fun aFreshLaunchFromTheNotificationIsRecorded() {
+        assertTrue(
+            shouldRecordNowPlayingLaunch(
+                action = MainActivity.ACTION_OPEN_NOW_PLAYING,
+                restoringState = false,
+            ),
+        )
+    }
+
+    @Test
+    fun recreatingTheActivityDoesNotReRecordTheLaunch() {
+        assertFalse(
+            shouldRecordNowPlayingLaunch(
+                action = MainActivity.ACTION_OPEN_NOW_PLAYING,
+                restoringState = true,
+            ),
+        )
+    }
+
+    @Test
+    fun aNormalLaunchIsNotRecorded() {
+        assertFalse(shouldRecordNowPlayingLaunch(action = "android.intent.action.MAIN", restoringState = false))
+    }
+
+    @Test
+    fun aLaunchWithoutAnActionIsNotRecorded() {
+        assertFalse(shouldRecordNowPlayingLaunch(action = null, restoringState = false))
+    }
+}

app/src/test/kotlin/com/subtracks/ui/NowPlayingRequestTest.kt

@@ -1,33 +0,0 @@
-package com.subtracks.ui
-
-import org.junit.Assert.assertFalse
-import org.junit.Assert.assertTrue
-import org.junit.Test
-
-class NowPlayingRequestTest {
-    @Test
-    fun aNotificationWithNothingPlayingDoesNotOpen() {
-        assertFalse(shouldOpenNowPlaying(request = 1, handled = 0, playerVisible = false))
-    }
-
-    @Test
-    fun aNotificationWithSomethingPlayingOpens() {
-        assertTrue(shouldOpenNowPlaying(request = 1, handled = 0, playerVisible = true))
-    }
-
-    @Test
-    fun anAlreadyHandledRequestDoesNotReopen() {
-        assertFalse(shouldOpenNowPlaying(request = 1, handled = 1, playerVisible = true))
-    }
-
-    @Test
-    fun aNewerRequestOpensAgain() {
-        assertTrue(shouldOpenNowPlaying(request = 2, handled = 1, playerVisible = true))
-    }
-
-    @Test
-    fun anOldRequestWaitsUntilSomethingIsPlaying() {
-        assertFalse(shouldOpenNowPlaying(request = 1, handled = 0, playerVisible = false))
-        assertTrue(shouldOpenNowPlaying(request = 1, handled = 0, playerVisible = true))
-    }
-}