#25 new: sftp upload

lib/data/model/sftp/req.dart

@@ -0,0 +1,84 @@
+import '../server/server_private_info.dart';
+import 'worker.dart';
+
+class SftpReqItem {
+  final ServerPrivateInfo spi;
+  final String remotePath;
+  final String localPath;
+
+  SftpReqItem(this.spi, this.remotePath, this.localPath);
+}
+
+enum SftpReqType { download, upload }
+
+class SftpReq {
+  final SftpReqItem item;
+  final String? privateKey;
+  final SftpReqType type;
+
+  SftpReq({required this.item, this.privateKey, required this.type});
+}
+
+class SftpReqStatus {
+  final int id;
+  final SftpReqItem item;
+  final void Function() notifyListeners;
+  late SftpWorker worker;
+
+  String get fileName => item.localPath.split('/').last;
+
+  // status of the download
+  double? progress;
+  SftpWorkerStatus? status;
+  int? size;
+  Exception? error;
+  Duration? spentTime;
+
+  SftpReqStatus({
+    required this.item,
+    required this.notifyListeners,
+    required SftpReqType type,
+    String? key,
+  }) : id = DateTime.now().microsecondsSinceEpoch {
+    worker = SftpWorker(
+      onNotify: onNotify,
+      item: item,
+      privateKey: key,
+      type: type,
+    );
+    worker.init();
+  }
+
+  @override
+  bool operator ==(Object other) => other is SftpReqStatus && id == other.id;
+
+  @override
+  int get hashCode => id ^ super.hashCode;
+
+  void onNotify(dynamic event) {
+    switch (event.runtimeType) {
+      case SftpWorkerStatus:
+        status = event;
+        if (status == SftpWorkerStatus.finished) {
+          worker.dispose();
+        }
+        break;
+      case double:
+        progress = event;
+        break;
+      case int:
+        size = event;
+        break;
+      case Exception:
+        error = event;
+        break;
+      case Duration:
+        spentTime = event;
+        break;
+      default:
+    }
+    notifyListeners();
+  }
+}
+
+enum SftpWorkerStatus { preparing, sshConnectted, downloading, finished }