Initial commit

lib/features/downloader/domain/repositories/file_system.dart

@@ -0,0 +1,29 @@
+import 'dart:async';
+
+/// Interface for interacting with the file system.
+abstract interface class FileSystem {
+  /// Ensures that the parent directory of the given path exists.
+  Future<void> ensureParentExists(String path);
+
+  /// Checks if a file or directory exists at the given path.
+  Future<bool> exists(String path);
+
+  /// Returns the size of the file at the given path.
+  Future<int> sizeOf(String path);
+
+  /// Truncates the file at the given path to zero length.
+  Future<void> truncate(String path);
+
+  /// Creates an empty file at the given path.
+  Future<void> createEmpty(String path);
+
+  /// Opens a stream sink for appending data to the file at the given path.
+  Future<StreamSink<List<int>>> openAppend(String path);
+
+  /// Verifies the integrity of a file at the given path.
+  Future<bool> verifyFile(
+    String path, {
+    required String expected,
+    required String algo,
+  });
+}