android, desktop, ios: warn on low storage before exporting or migrating the database, reject oversized migration

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/database/DatabaseView.kt

@@ -594,12 +594,36 @@ fun deleteChatDatabaseFilesAndState() {
   ntfManager.cancelAllNotifications()
 }
 
+// Advisory check before exporting the database — export transiently uses ~2x the data on disk.
+suspend fun confirmExportStorage(): Boolean {
+  databaseExportDir.mkdirs()
+  val requiredBytes = 2L * (
+    directoryFileCountAndSize(appFilesDir.absolutePath).second +
+      directoryFileCountAndSize(wallpapersDir.absolutePath).second +
+      File(dataDir, chatDatabaseFileName).length() +
+      File(dataDir, agentDatabaseFileName).length()
+  )
+  val availableBytes = databaseExportDir.usableSpace
+  if (availableBytes >= requiredBytes) return true
+  val proceed = CompletableDeferred<Boolean>()
+  AlertManager.shared.showAlertDialog(
+    title = generalGetString(MR.strings.not_enough_storage_title),
+    text = String.format(generalGetString(MR.strings.not_enough_storage_desc), formatBytes(requiredBytes), formatBytes(availableBytes)),
+    confirmText = generalGetString(MR.strings.chat_database_exported_continue),
+    onConfirm = { proceed.complete(true) },
+    onDismiss = { proceed.complete(false) },
+    onDismissRequest = { proceed.complete(false) },
+  )
+  return proceed.await()
+}
+
 private suspend fun exportArchive(
   m: ChatModel,
   progressIndicator: MutableState<Boolean>,
   chatArchiveFile: MutableState<String?>,
   saveArchiveLauncher: FileChooserLauncher
 ): Boolean {
+  if (!confirmExportStorage()) return false
   progressIndicator.value = true
   try {
     val (archiveFile, archiveErrors) = exportChatArchive(m, null, chatArchiveFile)

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/helpers/Utils.kt

@@ -126,6 +126,10 @@ const val MAX_FILE_SIZE_SMP: Long = 8000000
 
 const val MAX_FILE_SIZE_XFTP: Long = 1_073_741_824 // 1GB
 
+// Hard limit for standalone XFTP uploads (e.g. device migration archive);
+// mirrors maxFileSizeHard (gb 5) in simplexmq Simplex/FileTransfer/Description.hs
+const val MAX_FILE_SIZE_XFTP_HARD: Long = 5_368_709_120 // 5GB
+
 const val MAX_FILE_SIZE_LOCAL: Long = Long.MAX_VALUE
 
 expect fun getAppFileUri(fileName: String): URI

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/migration/MigrateFromDevice.kt

@@ -274,7 +274,7 @@ private fun MutableState<MigrationFromState>.ArchivingView() {
     ProgressView()
   }
   LaunchedEffect(Unit) {
-    exportArchive()
+    exportArchiveCheckingStorage()
   }
 }
 
@@ -480,6 +480,13 @@ private suspend fun MutableState<MigrationFromState>.verifyDatabasePassphrase(db
   }
 }
 
+private fun MutableState<MigrationFromState>.exportArchiveCheckingStorage() {
+  withBGApi {
+    if (confirmExportStorage()) exportArchive()
+    else state = MigrationFromState.UploadConfirmation
+  }
+}
+
 private fun MutableState<MigrationFromState>.exportArchive() {
   withLongRunningApi {
     try {
@@ -506,7 +513,15 @@ private fun MutableState<MigrationFromState>.exportArchive() {
 private fun MutableState<MigrationFromState>.uploadArchive(archivePath: String) {
   val totalBytes = File(archivePath).length()
   if (totalBytes > 0L) {
-    state = MigrationFromState.DatabaseInit(totalBytes, archivePath)
+    if (totalBytes > MAX_FILE_SIZE_XFTP_HARD) {
+      AlertManager.shared.showAlertMsg(
+        generalGetString(MR.strings.migrate_from_device_database_too_large_title),
+        String.format(generalGetString(MR.strings.migrate_from_device_database_too_large_desc), formatBytes(totalBytes), formatBytes(MAX_FILE_SIZE_XFTP_HARD))
+      )
+      state = MigrationFromState.UploadConfirmation
+    } else {
+      state = MigrationFromState.DatabaseInit(totalBytes, archivePath)
+    }
   } else {
     AlertManager.shared.showAlertMsg(generalGetString(MR.strings.migrate_from_device_exported_file_doesnt_exist))
     state = MigrationFromState.UploadConfirmation

apps/multiplatform/common/src/commonMain/resources/MR/base/strings.xml

@@ -2831,6 +2831,10 @@
   <string name="migrate_from_device_to_another_device">Migrate to another device</string>
   <string name="migrate_from_device_error_saving_settings">Error saving settings</string>
   <string name="migrate_from_device_exported_file_doesnt_exist">Exported file doesn\'t exist</string>
+  <string name="migrate_from_device_database_too_large_title">Database is too large</string>
+  <string name="migrate_from_device_database_too_large_desc">The exported archive (%1$s) is larger than the maximum size supported for migration (%2$s).</string>
+  <string name="not_enough_storage_title">You may not have enough storage</string>
+  <string name="not_enough_storage_desc">Exporting the database may need about %1$s of free space, but only %2$s is available. Continue anyway?</string>
   <string name="migrate_from_device_error_exporting_archive">Error exporting chat database</string>
   <string name="migrate_from_device_database_init">Preparing upload</string>
   <string name="migrate_from_device_error_uploading_archive">Error uploading the archive</string>