Add in-app copy/move, background downloads, and a Favorites tab

- WebDAV MOVE/COPY-backed copy/move for files and folders, with a
  destination picker (independent nav state so it doesn't disturb the
  Files tab's browsing position) and a conflict-resolution sheet
  (overwrite all / keep both / decide per item).
- Downloads now use the same foreground-service + notification approach
  as uploads, surviving app closure.
- Favorites is now its own tab (account-wide, via a WebDAV SEARCH query)
  instead of a Files-tab filter toggle, which couldn't represent
  favorited items outside the currently browsed folder correctly.
- Share sheet restyled to match the app's design language, plus a
  "share file directly" action via the OS share sheet; details sheet
  tab icons resized to match the bottom nav.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

android/app/src/main/AndroidManifest.xml

@@ -2,12 +2,19 @@
     <uses-permission android:name="android.permission.INTERNET"/>
     <!-- For local_auth's biometric app-lock (Settings > Security). -->
     <uses-permission android:name="android.permission.USE_BIOMETRIC"/>
-    <!-- For ShareUploadService, which keeps a "Share to Noo" upload going
-         (and cancellable from its notification) even if the app is fully
-         closed - see the service's own doc comment. -->
+    <!-- For ShareUploadService/DownloadService, which keep a "Share to Noo"
+         upload/download going (and cancellable from its notification) even
+         if the app is fully closed - see each service's own doc comment. -->
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC"/>
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
+    <!-- DownloadService's pre-Android-10 fallback only (MediaStore.Downloads
+         needs no runtime permission on API 29+, which is what targetSdk
+         actually enforces) - capped with maxSdkVersion so it's not even
+         requested on newer devices. -->
+    <uses-permission
+        android:name="android.permission.WRITE_EXTERNAL_STORAGE"
+        android:maxSdkVersion="28"/>
     <application
         android:label="Noo"
         android:name="${applicationName}"
@@ -65,6 +72,10 @@
             android:name=".ShareUploadService"
             android:exported="false"
             android:foregroundServiceType="dataSync"/>
+        <service
+            android:name=".DownloadService"
+            android:exported="false"
+            android:foregroundServiceType="dataSync"/>
         <!-- Hands back the file(s) a caller picked via the GET_CONTENT filter
              above - only the app's own cache/picker/ subfolder is exposed,
              see file_paths.xml. -->

android/app/src/main/kotlin/dev/ayushya/noo/DownloadService.kt

@@ -0,0 +1,307 @@
+package dev.ayushya.noo
+
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.PendingIntent
+import android.app.Service
+import android.content.ContentValues
+import android.content.Context
+import android.content.Intent
+import android.content.pm.ServiceInfo
+import android.net.Uri
+import android.os.Build
+import android.os.Environment
+import android.os.IBinder
+import android.provider.MediaStore
+import androidx.core.app.NotificationCompat
+import androidx.core.app.ServiceCompat
+import org.json.JSONArray
+import java.io.File
+import java.net.HttpURLConnection
+import java.net.URL
+import java.util.concurrent.atomic.AtomicBoolean
+
+/**
+ * Foreground service that downloads one or more files over WebDAV straight
+ * into the device's public Downloads folder, independent of MainActivity/
+ * the Flutter engine being alive - the download counterpart of
+ * ShareUploadService.kt (see its doc comment for the full rationale: only
+ * a real Android Service survives the app being closed mid-transfer, the
+ * same guarantee a real file-manager app's download notification gives
+ * you). Re-implements a plain WebDAV GET here in Kotlin for the same
+ * reason uploads do - keep NextcloudService.downloadToFile in sync if
+ * download semantics change.
+ *
+ * Started via the `dev.ayushya.noo/download_service` MethodChannel
+ * (MainActivity.kt). Shows one persistent, cancellable notification for
+ * the whole batch, same UX as ShareUploadService's.
+ */
+class DownloadService : Service() {
+    companion object {
+        const val ACTION_CANCEL = "dev.ayushya.noo.action.CANCEL_DOWNLOAD"
+        const val EXTRA_FILES = "files" // JSON array of {path, name, mimeType, size}
+        const val EXTRA_SERVER_URL = "serverUrl"
+        const val EXTRA_USERNAME = "username"
+        const val EXTRA_AUTH_HEADER = "authHeader"
+
+        private const val CHANNEL_ID = "file_downloads"
+        private const val NOTIFICATION_ID = 4301
+    }
+
+    private val cancelled = AtomicBoolean(false)
+    private var downloadThread: Thread? = null
+
+    private data class DownloadFile(
+        val path: String,
+        val name: String,
+        val mimeType: String?,
+        val size: Long?,
+    )
+
+    override fun onBind(intent: Intent?): IBinder? = null
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        if (intent?.action == ACTION_CANCEL) {
+            cancelled.set(true)
+            return START_NOT_STICKY
+        }
+
+        val filesJson = intent?.getStringExtra(EXTRA_FILES)
+        val serverUrl = intent?.getStringExtra(EXTRA_SERVER_URL)
+        val username = intent?.getStringExtra(EXTRA_USERNAME)
+        val authHeader = intent?.getStringExtra(EXTRA_AUTH_HEADER)
+        if (filesJson == null || serverUrl == null || username == null || authHeader == null) {
+            stopSelf()
+            return START_NOT_STICKY
+        }
+
+        createNotificationChannel()
+        ServiceCompat.startForeground(
+            this,
+            NOTIFICATION_ID,
+            buildProgressNotification("Preparing to download…", null, indeterminate = true),
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+                ServiceInfo.FOREGROUND_SERVICE_TYPE_DATA_SYNC
+            } else {
+                0
+            },
+        )
+
+        // A second batch arriving mid-download is dropped rather than
+        // queued - same tradeoff ShareUploadService makes, rare in
+        // practice and not worth a real queue for.
+        if (downloadThread == null) {
+            val files = parseFiles(filesJson)
+            downloadThread = Thread {
+                runDownloads(files, serverUrl, username, authHeader)
+            }.also { it.start() }
+        }
+
+        return START_NOT_STICKY
+    }
+
+    private fun parseFiles(json: String): List<DownloadFile> {
+        val arr = JSONArray(json)
+        return (0 until arr.length()).map { i ->
+            val obj = arr.getJSONObject(i)
+            DownloadFile(
+                path = obj.getString("path"),
+                name = obj.getString("name"),
+                mimeType = if (obj.isNull("mimeType")) null else obj.getString("mimeType"),
+                size = if (obj.isNull("size")) null else obj.getLong("size"),
+            )
+        }
+    }
+
+    private fun runDownloads(
+        files: List<DownloadFile>,
+        serverUrl: String,
+        username: String,
+        authHeader: String,
+    ) {
+        var succeeded = 0
+        var failed = 0
+        val cleanServer = serverUrl.trimEnd('/')
+
+        for ((index, file) in files.withIndex()) {
+            if (cancelled.get()) break
+            val label = if (files.size == 1) file.name else "${file.name} (${index + 1}/${files.size})"
+            try {
+                var cleanPath = file.path.trim()
+                if (!cleanPath.startsWith("/")) cleanPath = "/$cleanPath"
+                val encodedPath = cleanPath.split("/").joinToString("/") { Uri.encode(it) }
+                val url = URL("$cleanServer/remote.php/dav/files/$username$encodedPath")
+                val ok = downloadFile(file, url, authHeader) { received, total ->
+                    notify(
+                        buildProgressNotification(
+                            "Downloading $label…",
+                            progressFraction(received, total),
+                            indeterminate = total == null,
+                        ),
+                    )
+                }
+                if (ok) succeeded++ else failed++
+            } catch (e: Exception) {
+                failed++
+            }
+        }
+
+        val manager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+        val finalText = when {
+            cancelled.get() -> "Download cancelled"
+            failed == 0 && files.size == 1 -> "Downloaded ${files.first().name}"
+            failed == 0 -> "Downloaded $succeeded of ${files.size} files"
+            else -> "Downloaded $succeeded of ${files.size} files - $failed failed"
+        }
+        manager.notify(NOTIFICATION_ID, buildFinalNotification(finalText))
+
+        stopForeground(STOP_FOREGROUND_DETACH)
+        stopSelf()
+    }
+
+    private fun progressFraction(received: Long, total: Long?): Float? {
+        if (total == null || total <= 0) return null
+        return (received.toFloat() / total.toFloat()).coerceIn(0f, 1f)
+    }
+
+    /// Streams the GET response straight into the public Downloads
+    /// collection via MediaStore (API 29+) - scoped storage means a
+    /// background Service can't prompt a SAF picker the way `file_saver`
+    /// does from the Flutter/Activity side, so this writes directly to the
+    /// Downloads collection instead, same place a browser download lands.
+    /// Pre-Q devices fall back to the legacy public Downloads directory.
+    private fun downloadFile(
+        file: DownloadFile,
+        url: URL,
+        authHeader: String,
+        onProgress: (Long, Long?) -> Unit,
+    ): Boolean {
+        val connection = url.openConnection() as HttpURLConnection
+        return try {
+            connection.requestMethod = "GET"
+            connection.setRequestProperty("Authorization", authHeader)
+            connection.setRequestProperty("OCS-APIRequest", "true")
+            connection.connectTimeout = 15000
+            connection.readTimeout = 30000
+            connection.connect()
+
+            if (connection.responseCode !in 200..299) return false
+
+            val total = file.size ?: connection.contentLengthLong.takeIf { it > 0 }
+            val mimeType = file.mimeType ?: "application/octet-stream"
+            val outputUri = createDownloadsEntry(file.name, mimeType) ?: return false
+
+            val stream = contentResolver.openOutputStream(outputUri) ?: return false
+            stream.use { output ->
+                connection.inputStream.use { input ->
+                    val buffer = ByteArray(256 * 1024)
+                    var received = 0L
+                    var lastEmit = 0L
+                    while (!cancelled.get()) {
+                        val read = input.read(buffer)
+                        if (read == -1) break
+                        output.write(buffer, 0, read)
+                        received += read
+                        val now = System.currentTimeMillis()
+                        if (now - lastEmit >= 200) {
+                            lastEmit = now
+                            onProgress(received, total)
+                        }
+                    }
+                }
+            }
+
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+                val values = ContentValues().apply { put(MediaStore.Downloads.IS_PENDING, 0) }
+                contentResolver.update(outputUri, values, null, null)
+            }
+
+            if (cancelled.get()) {
+                contentResolver.delete(outputUri, null, null)
+                false
+            } else {
+                true
+            }
+        } catch (e: Exception) {
+            false
+        } finally {
+            connection.disconnect()
+        }
+    }
+
+    private fun createDownloadsEntry(name: String, mimeType: String): Uri? {
+        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            val values = ContentValues().apply {
+                put(MediaStore.Downloads.DISPLAY_NAME, name)
+                put(MediaStore.Downloads.MIME_TYPE, mimeType)
+                put(MediaStore.Downloads.IS_PENDING, 1)
+            }
+            contentResolver.insert(MediaStore.Downloads.EXTERNAL_CONTENT_URI, values)
+        } else {
+            @Suppress("DEPRECATION")
+            val downloadsDir =
+                Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)
+            if (!downloadsDir.exists()) downloadsDir.mkdirs()
+            Uri.fromFile(File(downloadsDir, name))
+        }
+    }
+
+    private fun notify(notification: Notification) {
+        val manager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+        manager.notify(NOTIFICATION_ID, notification)
+    }
+
+    private fun createNotificationChannel() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val channel = NotificationChannel(
+                CHANNEL_ID,
+                "File downloads",
+                NotificationManager.IMPORTANCE_LOW,
+            ).apply { description = "Progress for files downloaded from Noo" }
+            val manager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+            manager.createNotificationChannel(channel)
+        }
+    }
+
+    private fun buildProgressNotification(
+        text: String,
+        progress: Float?,
+        indeterminate: Boolean,
+    ): Notification {
+        val cancelIntent = Intent(this, DownloadService::class.java).apply { action = ACTION_CANCEL }
+        val cancelPendingIntent = PendingIntent.getService(
+            this,
+            0,
+            cancelIntent,
+            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE,
+        )
+        val builder = NotificationCompat.Builder(this, CHANNEL_ID)
+            .setSmallIcon(android.R.drawable.stat_sys_download)
+            .setContentTitle("Downloading from Noo")
+            .setContentText(text)
+            .setOnlyAlertOnce(true)
+            .setOngoing(true)
+            .addAction(android.R.drawable.ic_menu_close_clear_cancel, "Cancel", cancelPendingIntent)
+        when {
+            indeterminate -> builder.setProgress(100, 0, true)
+            progress != null -> builder.setProgress(100, (progress * 100).toInt(), false)
+        }
+        return builder.build()
+    }
+
+    private fun buildFinalNotification(text: String): Notification {
+        return NotificationCompat.Builder(this, CHANNEL_ID)
+            .setSmallIcon(android.R.drawable.stat_sys_download_done)
+            .setContentTitle("Noo")
+            .setContentText(text)
+            .setOngoing(false)
+            .setAutoCancel(true)
+            .build()
+    }
+
+    override fun onDestroy() {
+        cancelled.set(true)
+        super.onDestroy()
+    }
+}

android/app/src/main/kotlin/dev/ayushya/noo/MainActivity.kt

@@ -41,6 +41,7 @@ class MainActivity : FlutterFragmentActivity() {
     private val shareIntentChannelName = "dev.ayushya.noo/share_intent"
     private val newShareChannelName = "dev.ayushya.noo/share_intent/new"
     private val uploadServiceChannelName = "dev.ayushya.noo/upload_service"
+    private val downloadServiceChannelName = "dev.ayushya.noo/download_service"
     private val pickIntentChannelName = "dev.ayushya.noo/pick_intent"
     private val newPickChannelName = "dev.ayushya.noo/pick_intent/new"
     private val notificationPermissionRequestCode = 4202
@@ -84,6 +85,16 @@ class MainActivity : FlutterFragmentActivity() {
                 }
             }
 
+        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, downloadServiceChannelName)
+            .setMethodCallHandler { call, result ->
+                when (call.method) {
+                    "startDownload" -> {
+                        startDownloadService(call, result)
+                    }
+                    else -> result.notImplemented()
+                }
+            }
+
         MethodChannel(flutterEngine.dartExecutor.binaryMessenger, pickIntentChannelName)
             .setMethodCallHandler { call, result ->
                 when (call.method) {
@@ -215,6 +226,42 @@ class MainActivity : FlutterFragmentActivity() {
         result.success(null)
     }
 
+    /// Starts DownloadService with everything it needs to run entirely on
+    /// its own (see its doc comment) - same contract shape as
+    /// [startUploadService], kept in sync manually for the same reason.
+    private fun startDownloadService(call: MethodCall, result: MethodChannel.Result) {
+        val filesJson = call.argument<String>("files")
+        val serverUrl = call.argument<String>("serverUrl")
+        val username = call.argument<String>("username")
+        val authHeader = call.argument<String>("authHeader")
+        if (filesJson == null || serverUrl == null || username == null || authHeader == null) {
+            result.error("bad_args", "Missing required download arguments", null)
+            return
+        }
+
+        if (Build.VERSION.SDK_INT >= 33 &&
+            ContextCompat.checkSelfPermission(this, Manifest.permission.POST_NOTIFICATIONS) !=
+            PackageManager.PERMISSION_GRANTED
+        ) {
+            // Fire-and-forget: the service works fine even if this is denied,
+            // it just won't be able to show progress/cancel in a notification.
+            ActivityCompat.requestPermissions(
+                this,
+                arrayOf(Manifest.permission.POST_NOTIFICATIONS),
+                notificationPermissionRequestCode,
+            )
+        }
+
+        val serviceIntent = Intent(this, DownloadService::class.java).apply {
+            putExtra(DownloadService.EXTRA_FILES, filesJson)
+            putExtra(DownloadService.EXTRA_SERVER_URL, serverUrl)
+            putExtra(DownloadService.EXTRA_USERNAME, username)
+            putExtra(DownloadService.EXTRA_AUTH_HEADER, authHeader)
+        }
+        ContextCompat.startForegroundService(this, serviceIntent)
+        result.success(null)
+    }
+
     /// Non-null only when this Activity was launched (or re-delivered a new
     /// Intent) as another app's GET_CONTENT picker - the mimeType filter and
     /// multi-select flag the caller asked for, plus a best-effort display