fix(notification): open tapped chat at bottom (#984)

Co-authored-by: M57 <41645758+Hy4ri@users.noreply.github.com>

app/src/main/java/com/m57/hermescontrol/MainActivity.kt

@@ -96,6 +96,6 @@ class MainActivity : ComponentActivity() {
         if (intent?.action != ACTION_OPEN_CHAT_FROM_NOTIFICATION) return
         val sessionId = intent.getStringExtra(NotificationReplyReceiver.EXTRA_SESSION_ID)
         intent.removeExtra(NotificationReplyReceiver.EXTRA_SESSION_ID)
-        sessionId?.takeIf { it.isNotBlank() }?.let(NavigationController::openChatSession)
+        sessionId?.takeIf { it.isNotBlank() }?.let(NavigationController::openChatSessionFromNotification)
     }
 }

app/src/main/java/com/m57/hermescontrol/NavigationController.kt

@@ -6,6 +6,12 @@ import androidx.compose.runtime.setValue
 import androidx.navigation3.runtime.NavBackStack
 import androidx.navigation3.runtime.NavKey
 
+data class PendingChatNavigation(
+    val sessionId: String,
+    val scrollToBottom: Boolean,
+    val requestId: Long,
+)
+
 /**
  * Central navigation controller with deduplication guard.
  *
@@ -19,8 +25,11 @@ import androidx.navigation3.runtime.NavKey
  */
 object NavigationController {
     var backStack: NavBackStack<NavKey>? = null
-    var pendingSessionId: String? by mutableStateOf(null)
+    var pendingChatNavigation: PendingChatNavigation? by mutableStateOf(null)
         private set
+    val pendingSessionId: String? get() = pendingChatNavigation?.sessionId
+
+    private var nextChatNavigationRequestId = 0L
 
     // Top-level primary screens (Chat, Skills, Cron, System, Settings)
     private val primaryScreens: MutableSet<NavKey> =
@@ -50,12 +59,31 @@ object NavigationController {
     }
 
     fun openChatSession(sessionId: String) {
+        queueChatNavigation(sessionId, scrollToBottom = false)
+    }
+
+    fun openChatSessionFromNotification(sessionId: String) {
+        queueChatNavigation(sessionId, scrollToBottom = true)
+    }
+
+    private fun queueChatNavigation(
+        sessionId: String,
+        scrollToBottom: Boolean,
+    ) {
         if (sessionId.isBlank()) return
-        pendingSessionId = sessionId
+        pendingChatNavigation =
+            PendingChatNavigation(
+                sessionId = sessionId,
+                scrollToBottom = scrollToBottom,
+                requestId = ++nextChatNavigationRequestId,
+            )
         navigateTo(ChatScreen)
     }
 
-    fun consumePendingSessionId(): String? = pendingSessionId.also { pendingSessionId = null }
+    fun consumePendingChatNavigation(): PendingChatNavigation? =
+        pendingChatNavigation.also { pendingChatNavigation = null }
+
+    fun consumePendingSessionId(): String? = consumePendingChatNavigation()?.sessionId
 
     /** Clear the stack and navigate to the given screen atomically. */
     fun resetTo(screen: NavKey) {

app/src/main/java/com/m57/hermescontrol/ui/chat/components/ChatLifecycleEffects.kt

@@ -44,13 +44,17 @@ fun ChatLifecycleEffects(
     val lifecycleOwner = LocalLifecycleOwner.current
 
     // Switch to session from notification/history
-    val pendingSessionId = NavigationController.pendingSessionId
+    val pendingNavigation = NavigationController.pendingChatNavigation
-    LaunchedEffect(sessionId, pendingSessionId, connectionStatus) {
+    LaunchedEffect(sessionId, pendingNavigation, connectionStatus) {
         if (connectionStatus != ConnectionStatus.CONNECTED) return@LaunchedEffect
-        val target = NavigationController.consumePendingSessionId() ?: sessionId
+        val request = NavigationController.consumePendingChatNavigation()
+        val target = request?.sessionId ?: sessionId
         if (!target.isNullOrBlank()) {
             viewModel.switchSession(target)
         }
+        if (request?.scrollToBottom == true) {
+            scrollController.jumpToBottom(animated = false)
+        }
     }
 
     // Land instantly at the bottom on a session switch (issue #682).

app/src/test/java/com/m57/hermescontrol/NavigationControllerTest.kt

@@ -146,6 +146,32 @@ class NavigationControllerTest {
         assertNull(NavigationController.consumePendingSessionId())
     }
 
+    @Test
+    fun `notification chat request asks for bottom even when chat is already active`() {
+        val backStack = NavBackStack<NavKey>(ChatScreen)
+        NavigationController.backStack = backStack
+
+        NavigationController.openChatSessionFromNotification("stored-session")
+        val first = NavigationController.consumePendingChatNavigation()
+        NavigationController.openChatSessionFromNotification("stored-session")
+        val second = NavigationController.consumePendingChatNavigation()
+
+        assertEquals(1, backStack.size)
+        assertEquals("stored-session", first?.sessionId)
+        assertTrue(first?.scrollToBottom == true)
+        assertTrue(second?.scrollToBottom == true)
+        assertTrue("repeated taps must be distinct events", first?.requestId != second?.requestId)
+    }
+
+    @Test
+    fun `history chat request does not force bottom`() {
+        NavigationController.backStack = NavBackStack<NavKey>(HistoryScreen)
+
+        NavigationController.openChatSession("stored-session")
+
+        assertFalse(NavigationController.consumePendingChatNavigation()?.scrollToBottom == true)
+    }
+
     // ── resetTo: atomic clear + navigate ──────────────────────────────────
 
     @Test