feat: fix notifications on Android 13+/16, add Log tab, fix ON_CHANGE detection

- Request POST_NOTIFICATIONS permission at runtime in MainActivity (primary fix
  for notifications never appearing on Android 13+ phones including Android 16)
- Register all 4 notification channels eagerly in SyncFlowApp.onCreate() instead
  of lazily inside workers
- Add FOREGROUND_SERVICE_SHORT_SERVICE permission + shortService foreground type
  for Android 16 foreground service compatibility
- Add global activity Log tab (new tab 2 in main nav) showing all sync events
  across all pairs, grouped by date with pair name, event icon, and file detail
- Fix FileWatchService ON_CHANGE detection: ContentObserver on SAF tree URIs only
  fires for SAF-API writes, not raw filesystem writes. Now resolves primary:/*
  tree URIs to /storage/emulated/0/* and uses FileObserver for reliable detection
- Bump version to 1.0.21 (build 22)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/src/main/AndroidManifest.xml

@@ -8,6 +8,7 @@
     <uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE" tools:ignore="ScopedStorage" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_SHORT_SERVICE" />
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
@@ -71,13 +72,13 @@
         <!-- File watcher for ON_CHANGE sync pairs -->
         <service
             android:name=".worker.FileWatchService"
-            android:foregroundServiceType="dataSync"
+            android:foregroundServiceType="dataSync|shortService"
             android:exported="false" />
 
         <!-- Required on API 29+ so WorkManager can start a typed foreground service -->
         <service
             android:name="androidx.work.impl.foreground.SystemForegroundService"
-            android:foregroundServiceType="dataSync"
+            android:foregroundServiceType="dataSync|shortService"
             tools:node="merge" />
 
         <!-- Remove WorkManager's default initializer — app uses on-demand init via Configuration.Provider -->

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

@@ -1,9 +1,12 @@
 package com.syncflow
 
+import android.Manifest
+import android.content.pm.PackageManager
 import android.os.Build
 import android.os.Bundle
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AppCompatActivity
 import androidx.biometric.BiometricManager
 import androidx.biometric.BiometricManager.Authenticators.BIOMETRIC_STRONG
@@ -49,10 +52,14 @@ class MainActivity : AppCompatActivity() {
     private var isLocked by mutableStateOf(false)
     private var showRetry by mutableStateOf(false)
 
+    private val requestNotificationPermission =
+        registerForActivityResult(ActivityResultContracts.RequestPermission()) { /* proceed regardless */ }
+
     override fun onCreate(savedInstanceState: Bundle?) {
         installSplashScreen()
         super.onCreate(savedInstanceState)
         enableEdgeToEdge()
+        requestNotificationPermissionIfNeeded()
         setContent {
             SyncFlowTheme {
                 Surface(modifier = Modifier.fillMaxSize()) {
@@ -127,6 +134,16 @@ class MainActivity : AppCompatActivity() {
             BIOMETRIC_WEAK or DEVICE_CREDENTIAL
     }
 
+    private fun requestNotificationPermissionIfNeeded() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            if (ContextCompat.checkSelfPermission(this, Manifest.permission.POST_NOTIFICATIONS)
+                != PackageManager.PERMISSION_GRANTED
+            ) {
+                requestNotificationPermission.launch(Manifest.permission.POST_NOTIFICATIONS)
+            }
+        }
+    }
+
     private fun canAuthenticate(): Boolean {
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R)
             return BiometricManager.from(this).canAuthenticate(BIOMETRIC_STRONG) == BiometricManager.BIOMETRIC_SUCCESS

app/src/main/kotlin/com/syncflow/SyncFlowApp.kt

@@ -1,6 +1,9 @@
 package com.syncflow
 
 import android.app.Application
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.content.Context
 import androidx.hilt.work.HiltWorkerFactory
 import androidx.work.Configuration
 import com.syncflow.data.db.SyncPairDao
@@ -22,6 +25,7 @@ class SyncFlowApp : Application(), Configuration.Provider {
     override fun onCreate() {
         super.onCreate()
         if (BuildConfig.DEBUG) Timber.plant(Timber.DebugTree())
+        createNotificationChannels()
         // Start file watcher on every app launch for any existing ON_CHANGE pairs
         CoroutineScope(Dispatchers.IO).launch {
             val hasOnChange = syncPairDao.getEnabled().any { it.scheduleType == ScheduleType.ON_CHANGE }
@@ -29,6 +33,27 @@ class SyncFlowApp : Application(), Configuration.Provider {
         }
     }
 
+    private fun createNotificationChannels() {
+        val nm = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+        listOf(
+            NotificationChannel("sync_progress", "Sync progress", NotificationManager.IMPORTANCE_LOW).apply {
+                description = "Shown while a sync is running"
+            },
+            NotificationChannel("sync_complete", "Sync complete", NotificationManager.IMPORTANCE_LOW).apply {
+                description = "Summary after each successful sync"
+            },
+            NotificationChannel("sync_alerts", "Sync errors", NotificationManager.IMPORTANCE_DEFAULT).apply {
+                description = "Alerts for sync failures and conflicts"
+            },
+            NotificationChannel("sync_watching", "File watching", NotificationManager.IMPORTANCE_MIN).apply {
+                description = "Background service watching folders for changes"
+                setShowBadge(false)
+            },
+        ).forEach { channel ->
+            if (nm.getNotificationChannel(channel.id) == null) nm.createNotificationChannel(channel)
+        }
+    }
+
     override val workManagerConfiguration: Configuration
         get() = Configuration.Builder()
             .setWorkerFactory(workerFactory)

app/src/main/kotlin/com/syncflow/data/db/SyncEventDao.kt

@@ -9,6 +9,9 @@ interface SyncEventDao {
     @Query("SELECT * FROM sync_events WHERE syncPairId = :pairId ORDER BY timestamp DESC LIMIT :limit")
     fun observeRecent(pairId: Long, limit: Int = 200): Flow<List<SyncEventEntity>>
 
+    @Query("SELECT * FROM sync_events ORDER BY timestamp DESC LIMIT :limit")
+    fun observeAll(limit: Int = 500): Flow<List<SyncEventEntity>>
+
     @Insert
     suspend fun insert(entity: SyncEventEntity): Long
 

app/src/main/kotlin/com/syncflow/ui/log/LogScreen.kt

@@ -0,0 +1,178 @@
+package com.syncflow.ui.log
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.*
+import androidx.compose.material.icons.outlined.Circle
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import com.syncflow.domain.model.SyncEventType
+import java.time.Duration
+import java.time.Instant
+import java.time.ZoneId
+import java.time.format.DateTimeFormatter
+import java.time.format.FormatStyle
+
+@Composable
+fun LogScreen(
+    modifier: Modifier = Modifier,
+    vm: LogViewModel = hiltViewModel(),
+) {
+    val entries by vm.entries.collectAsState()
+
+    if (entries.isEmpty()) {
+        Box(
+            modifier = modifier.fillMaxSize(),
+            contentAlignment = Alignment.Center,
+        ) {
+            Column(
+                horizontalAlignment = Alignment.CenterHorizontally,
+                verticalArrangement = Arrangement.spacedBy(8.dp),
+            ) {
+                Icon(
+                    Icons.Default.Notifications,
+                    contentDescription = null,
+                    modifier = Modifier.size(72.dp),
+                    tint = MaterialTheme.colorScheme.primary.copy(alpha = 0.35f),
+                )
+                Text("No activity yet", style = MaterialTheme.typography.titleMedium)
+                Text(
+                    "Sync events will appear here",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        }
+    } else {
+        LazyColumn(
+            modifier = modifier.fillMaxSize(),
+            contentPadding = PaddingValues(horizontal = 16.dp, vertical = 8.dp),
+            verticalArrangement = Arrangement.spacedBy(0.dp),
+        ) {
+            // Group entries by calendar date
+            val grouped = entries.groupBy { entry ->
+                entry.event.timestamp.atZone(ZoneId.systemDefault()).toLocalDate()
+            }
+            grouped.forEach { (date, dayEntries) ->
+                item(key = date.toString()) {
+                    Text(
+                        text = date.toRelativeLabel(),
+                        style = MaterialTheme.typography.labelMedium,
+                        color = MaterialTheme.colorScheme.primary,
+                        modifier = Modifier.padding(top = 16.dp, bottom = 4.dp),
+                    )
+                }
+                items(dayEntries, key = { it.event.id }) { entry ->
+                    LogEntryRow(entry)
+                    HorizontalDivider(
+                        color = MaterialTheme.colorScheme.outline.copy(alpha = 0.3f),
+                        modifier = Modifier.padding(start = 52.dp),
+                    )
+                }
+            }
+            item { Spacer(Modifier.height(80.dp)) }
+        }
+    }
+}
+
+@Composable
+private fun LogEntryRow(entry: LogEntry) {
+    val (icon, tint) = entry.event.eventType.iconAndTint()
+    val timeFmt = DateTimeFormatter.ofLocalizedTime(FormatStyle.SHORT)
+    val timeStr = entry.event.timestamp.atZone(ZoneId.systemDefault()).let { timeFmt.format(it) }
+
+    Row(
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(vertical = 10.dp),
+        verticalAlignment = Alignment.Top,
+    ) {
+        // Icon bubble
+        Surface(
+            shape = RoundedCornerShape(10.dp),
+            color = tint.copy(alpha = 0.12f),
+            modifier = Modifier.size(36.dp),
+        ) {
+            Box(contentAlignment = Alignment.Center) {
+                Icon(icon, contentDescription = null, Modifier.size(18.dp), tint = tint)
+            }
+        }
+        Spacer(Modifier.width(12.dp))
+        Column(modifier = Modifier.weight(1f)) {
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                horizontalArrangement = Arrangement.SpaceBetween,
+                verticalAlignment = Alignment.CenterVertically,
+            ) {
+                Text(
+                    entry.pairName,
+                    style = MaterialTheme.typography.labelMedium,
+                    color = MaterialTheme.colorScheme.primary,
+                    modifier = Modifier.weight(1f, fill = false),
+                )
+                Text(
+                    timeStr,
+                    style = MaterialTheme.typography.labelSmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+            Spacer(Modifier.height(2.dp))
+            Text(
+                text = entry.event.eventType.label(),
+                style = MaterialTheme.typography.bodySmall,
+            )
+            val detail = entry.event.filePath ?: entry.event.message
+            if (detail != null) {
+                Text(
+                    text = detail,
+                    style = MaterialTheme.typography.labelSmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    maxLines = 1,
+                )
+            }
+        }
+    }
+}
+
+@Composable
+private fun SyncEventType.iconAndTint(): Pair<ImageVector, Color> = when (this) {
+    SyncEventType.SYNC_STARTED     -> Icons.Default.Sync to MaterialTheme.colorScheme.secondary
+    SyncEventType.SYNC_COMPLETED   -> Icons.Default.CheckCircle to MaterialTheme.colorScheme.primary
+    SyncEventType.SYNC_FAILED      -> Icons.Default.Error to MaterialTheme.colorScheme.error
+    SyncEventType.FILE_UPLOADED    -> Icons.Default.CloudUpload to MaterialTheme.colorScheme.secondary
+    SyncEventType.FILE_DOWNLOADED  -> Icons.Default.CloudDownload to MaterialTheme.colorScheme.secondary
+    SyncEventType.FILE_DELETED     -> Icons.Default.DeleteForever to MaterialTheme.colorScheme.tertiary
+    SyncEventType.FILE_SKIPPED     -> Icons.Outlined.Circle to MaterialTheme.colorScheme.onSurfaceVariant
+    SyncEventType.CONFLICT_DETECTED -> Icons.Default.Warning to MaterialTheme.colorScheme.tertiary
+    SyncEventType.CONFLICT_RESOLVED -> Icons.Default.CheckCircle to MaterialTheme.colorScheme.primary
+}
+
+private fun SyncEventType.label(): String = when (this) {
+    SyncEventType.SYNC_STARTED      -> "Sync started"
+    SyncEventType.SYNC_COMPLETED    -> "Sync completed"
+    SyncEventType.SYNC_FAILED       -> "Sync failed"
+    SyncEventType.FILE_UPLOADED     -> "File uploaded"
+    SyncEventType.FILE_DOWNLOADED   -> "File downloaded"
+    SyncEventType.FILE_DELETED      -> "File deleted"
+    SyncEventType.FILE_SKIPPED      -> "File skipped"
+    SyncEventType.CONFLICT_DETECTED -> "Conflict detected"
+    SyncEventType.CONFLICT_RESOLVED -> "Conflict resolved"
+}
+
+private fun java.time.LocalDate.toRelativeLabel(): String {
+    val today = java.time.LocalDate.now()
+    return when {
+        this == today -> "Today"
+        this == today.minusDays(1) -> "Yesterday"
+        else -> DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).format(this)
+    }
+}

app/src/main/kotlin/com/syncflow/ui/log/LogViewModel.kt

@@ -0,0 +1,29 @@
+package com.syncflow.ui.log
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.syncflow.data.db.SyncEventDao
+import com.syncflow.data.db.SyncPairDao
+import com.syncflow.data.db.entities.SyncEventEntity
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.stateIn
+import javax.inject.Inject
+
+data class LogEntry(val event: SyncEventEntity, val pairName: String)
+
+@HiltViewModel
+class LogViewModel @Inject constructor(
+    syncEventDao: SyncEventDao,
+    syncPairDao: SyncPairDao,
+) : ViewModel() {
+
+    val entries = combine(
+        syncEventDao.observeAll(500),
+        syncPairDao.observeAll(),
+    ) { events, pairs ->
+        val pairNames = pairs.associateBy({ it.id }, { it.name })
+        events.map { LogEntry(it, pairNames[it.syncPairId] ?: "Unknown") }
+    }.stateIn(viewModelScope, SharingStarted.WhileSubscribed(5_000), emptyList())
+}

app/src/main/kotlin/com/syncflow/ui/main/MainShell.kt

@@ -20,8 +20,10 @@ import androidx.compose.foundation.pager.rememberPagerState
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Add
 import androidx.compose.material.icons.filled.ManageAccounts
+import androidx.compose.material.icons.filled.Notifications
 import androidx.compose.material.icons.filled.Sync
 import androidx.compose.material.icons.outlined.ManageAccounts
+import androidx.compose.material.icons.outlined.NotificationsNone
 import androidx.compose.material.icons.outlined.Sync
 import androidx.compose.material3.*
 import androidx.compose.runtime.Composable
@@ -32,6 +34,7 @@ import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.unit.dp
 import com.syncflow.R
 import com.syncflow.ui.home.HomeScreen
+import com.syncflow.ui.log.LogScreen
 import com.syncflow.ui.settings.SettingsScreen
 import kotlinx.coroutines.launch
 
@@ -42,7 +45,7 @@ fun MainShell(
     onPairClick: (Long) -> Unit,
     onAddAccount: () -> Unit,
 ) {
-    val pagerState = rememberPagerState(pageCount = { 2 })
+    val pagerState = rememberPagerState(pageCount = { 3 })
     val scope = rememberCoroutineScope()
     val currentPage = pagerState.currentPage
 
@@ -88,7 +91,18 @@ fun MainShell(
                     onClick = { scope.launch { pagerState.animateScrollToPage(1) } },
                     icon = {
                         Icon(
-                            if (currentPage == 1) Icons.Filled.ManageAccounts else Icons.Outlined.ManageAccounts,
+                            if (currentPage == 1) Icons.Filled.Notifications else Icons.Outlined.NotificationsNone,
+                            contentDescription = null,
+                        )
+                    },
+                    label = { Text("Log") },
+                )
+                NavigationBarItem(
+                    selected = currentPage == 2,
+                    onClick = { scope.launch { pagerState.animateScrollToPage(2) } },
+                    icon = {
+                        Icon(
+                            if (currentPage == 2) Icons.Filled.ManageAccounts else Icons.Outlined.ManageAccounts,
                             contentDescription = null,
                         )
                     },
@@ -120,7 +134,8 @@ fun MainShell(
         ) { page ->
             when (page) {
                 0 -> HomeScreen(onAddPair = onAddPair, onPairClick = onPairClick)
-                1 -> SettingsScreen(onAddAccount = onAddAccount)
+                1 -> LogScreen()
+                2 -> SettingsScreen(onAddAccount = onAddAccount)
             }
         }
     }

app/src/main/kotlin/com/syncflow/worker/FileWatchService.kt

@@ -10,6 +10,7 @@ import android.os.FileObserver
 import android.os.Handler
 import android.os.IBinder
 import android.os.Looper
+import android.provider.DocumentsContract
 import androidx.core.app.NotificationCompat
 import androidx.work.ExistingWorkPolicy
 import androidx.work.WorkManager
@@ -81,35 +82,25 @@ class FileWatchService : Service() {
             val localPath = pair.localPath
 
             if (localPath.startsWith("content://")) {
-                val treeUri = Uri.parse(localPath)
+                // Try to resolve the SAF tree URI to a real filesystem path so we can use
-                val observer = object : ContentObserver(mainHandler) {
+                // FileObserver. ContentObserver on a DocumentsProvider tree URI only fires
-                    override fun onChange(selfChange: Boolean) = onChangeDetected(pairId, pair.wifiOnly, pair.chargingOnly)
+                // when changes come through the SAF API, not for raw filesystem writes.
-                    override fun onChange(selfChange: Boolean, uri: Uri?) = onChangeDetected(pairId, pair.wifiOnly, pair.chargingOnly)
+                val realPath = safTreeUriToRealPath(localPath)
-                }
+                if (realPath != null) {
-                contentResolver.registerContentObserver(treeUri, true, observer)
+                    watchPath(realPath, pairId, pair.wifiOnly, pair.chargingOnly)
-                contentObservers[pairId] = observer
-                Timber.d("FileWatchService: watching SAF URI for pair $pairId")
-            } else {
-                val dir = File(localPath)
-                if (!dir.exists()) {
-                    Timber.w("FileWatchService: path does not exist for pair $pairId: $localPath")
-                    return@forEach
-                }
-                val mask = FileObserver.CREATE or FileObserver.DELETE or FileObserver.MODIFY or
-                           FileObserver.MOVED_FROM or FileObserver.MOVED_TO
-                val observer = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
-                    object : FileObserver(dir, mask) {
-                        override fun onEvent(event: Int, path: String?) = onChangeDetected(pairId, pair.wifiOnly, pair.chargingOnly)
-                    }
                 } else {
-                    @Suppress("DEPRECATION")
+                    // Fallback: register a ContentObserver for SAF paths that can't be resolved
-                    object : FileObserver(localPath, mask) {
+                    val treeUri = Uri.parse(localPath)
-                        override fun onEvent(event: Int, path: String?) = onChangeDetected(pairId, pair.wifiOnly, pair.chargingOnly)
+                    val observer = object : ContentObserver(mainHandler) {
+                        override fun onChange(selfChange: Boolean) = onChangeDetected(pairId, pair.wifiOnly, pair.chargingOnly)
+                        override fun onChange(selfChange: Boolean, uri: Uri?) = onChangeDetected(pairId, pair.wifiOnly, pair.chargingOnly)
                     }
+                    contentResolver.registerContentObserver(treeUri, true, observer)
+                    contentObservers[pairId] = observer
+                    Timber.d("FileWatchService: watching SAF URI (ContentObserver fallback) for pair $pairId")
                 }
-                observer.startWatching()
+            } else {
-                fileObservers[pairId] = observer
+                watchPath(localPath, pairId, pair.wifiOnly, pair.chargingOnly)
-                Timber.d("FileWatchService: watching filesystem path for pair $pairId: $localPath")
             }
         }
 
@@ -122,6 +113,46 @@ class FileWatchService : Service() {
         }
     }
 
+    private fun safTreeUriToRealPath(uriString: String): String? {
+        return try {
+            val treeUri = Uri.parse(uriString)
+            val docId = DocumentsContract.getTreeDocumentId(treeUri)
+            // docId format is "primary:RelativePath" for primary internal storage
+            if (docId.startsWith("primary:")) {
+                val relative = docId.removePrefix("primary:")
+                "/storage/emulated/0/$relative"
+            } else {
+                null
+            }
+        } catch (e: Exception) {
+            Timber.w("FileWatchService: could not resolve SAF URI to real path: $e")
+            null
+        }
+    }
+
+    private fun watchPath(path: String, pairId: Long, wifiOnly: Boolean, chargingOnly: Boolean) {
+        val dir = File(path)
+        if (!dir.exists()) {
+            Timber.w("FileWatchService: path does not exist for pair $pairId: $path")
+            return
+        }
+        val mask = FileObserver.CREATE or FileObserver.DELETE or FileObserver.MODIFY or
+                   FileObserver.MOVED_FROM or FileObserver.MOVED_TO
+        val observer = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            object : FileObserver(dir, mask) {
+                override fun onEvent(event: Int, p: String?) = onChangeDetected(pairId, wifiOnly, chargingOnly)
+            }
+        } else {
+            @Suppress("DEPRECATION")
+            object : FileObserver(path, mask) {
+                override fun onEvent(event: Int, p: String?) = onChangeDetected(pairId, wifiOnly, chargingOnly)
+            }
+        }
+        observer.startWatching()
+        fileObservers[pairId] = observer
+        Timber.d("FileWatchService: watching filesystem path for pair $pairId: $path")
+    }
+
     private fun onChangeDetected(pairId: Long, wifiOnly: Boolean, chargingOnly: Boolean) {
         debounceJobs[pairId]?.cancel()
         debounceJobs[pairId] = scope.launch {

version.properties

@@ -1,2 +1,2 @@
-VERSION_NAME=1.0.19
+VERSION_NAME=1.0.21
-VERSION_CODE=20
+VERSION_CODE=22