add: remotefs/DownloadDirectory function to support recursive download

Signed-off-by: Michael Kaplan <[email protected]>

remotefs/downloaddirectory.go

@@ -0,0 +1,43 @@
+package remotefs
+
+import (
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+)
+
+// DownloadDirectory downloads all files and directories recursively from the remote system to local directory.
+func DownloadDirectory(fsys FS, src, dst string) error {
+	walkErr := fs.WalkDir(fsys, src, func(path string, dir fs.DirEntry, err error) error {
+		if err != nil {
+			return fmt.Errorf("walk remote directory: %w", err)
+		}
+
+		relPath, err := filepath.Rel(src, path)
+		if err != nil {
+			return fmt.Errorf("calculate relative path: %w", err)
+		}
+		targetPath := filepath.Join(dst, relPath)
+
+		if dir.IsDir() {
+			dirInfo, err := dir.Info()
+			if err != nil {
+				return fmt.Errorf("get dir info: %w", err)
+			}
+			if err := os.MkdirAll(targetPath, dirInfo.Mode()&os.ModePerm); err != nil {
+				return fmt.Errorf("create local directory: %w", err)
+			}
+		} else {
+			if err := Download(fsys, path, targetPath); err != nil {
+				return fmt.Errorf("download file: %w", err)
+			}
+		}
+		return nil
+	})
+
+	if walkErr != nil {
+		return fmt.Errorf("walk remote directory tree: %w", walkErr)
+	}
+	return nil
+}