listDirectory method

Implementation

@override
Future<List<FileSystemEntity>> listDirectory(String path) async {
  try {
    final resolvedPhysicalPath = resolvePath(path);

    // Special Case: Listing the virtual root ('/').
    // We don't list a physical directory. Instead, we list the *keys*
    // of the directory mappings, representing the top-level virtual folders.
    if (resolvedPhysicalPath == rootDirectory) {
      // Return Directory objects where the path is just the mapping key (e.g., 'docs', 'pics').
      // This represents the virtual entries available at the root.
      // The FTP client will see these as directories.
      return directoryMappings.keys
          .map((key) =>
              Directory(key)) // Represent virtual entry using its key.
          .toList();
    }

    // Standard Case: Listing a directory within a mapping.
    // The resolved path is a physical directory path.
    final dir = Directory(resolvedPhysicalPath);
    if (!await dir.exists()) {
      throw FileSystemException(
          "Directory not found: '$path' (resolved to '$resolvedPhysicalPath')",
          path);
    }

    // Get the physical entities within the directory.
    // NOTE: listSync() can block on large directories. Consider async list() if performance is critical.
    final physicalEntities = dir.listSync();
    final virtualEntities = <FileSystemEntity>[];

    // Convert physical entities back to virtual representations.
    for (var entity in physicalEntities) {
      // Get the virtual path corresponding to the physical entity's path.
      final virtualPath = _getVirtualPath(entity.path);
      // Create a new FileSystemEntity (File or Directory) using the *virtual* path.
      // This is what the FTP client will see.
      if (entity is Directory) {
        virtualEntities.add(Directory(virtualPath));
      } else if (entity is File) {
        virtualEntities.add(File(virtualPath));
      }
      // Ignore other types like Links for simplicity, or handle as needed.
    }

    return virtualEntities;
  } catch (e) {
    if (e is FileSystemException) {
      rethrow;
    }
    throw FileSystemException(
        "Failed to list directory '$path': ${e.toString()}", path);
  }
}