add: remotefs/DownloadDirectory function to support recursive download

remotefs/downloaddirectory.go

@@ -0,0 +1,49 @@
+package remotefs
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// DownloadDirectory downloads all files and directories recursively from the remote system to local directory.
+func DownloadDirectory(fs FS, src, dst string) error {
+	// Ensure the destination directory is created even if empty
+	srcInfo, err := fs.Stat(src)
+	if err != nil {
+		return fmt.Errorf("stat dir for download: %w", err)
+	}
+	mode := srcInfo.Mode() & os.ModePerm
+	if err := os.MkdirAll(dst, mode); err != nil {
+		return fmt.Errorf("create empty dir for download: %w", err)
+	}
+
+	entries, err := fs.ReadDir(src)
+	if err != nil {
+		return fmt.Errorf("read dir for download: %w", err)
+	}
+
+	for _, entry := range entries {
+		srcPath := filepath.Join(src, entry.Name())
+		dstPath := filepath.Join(dst, entry.Name())
+
+		info, err := entry.Info()
+		if err != nil {
+			return fmt.Errorf("dir info for download: %w", err)
+		}
+
+		if info.IsDir() {
+			if err := os.MkdirAll(dstPath, info.Mode()); err != nil {
+				return fmt.Errorf("create dir for download: %w", err)
+			}
+			if err := DownloadDirectory(fs, srcPath, dstPath); err != nil {
+				return fmt.Errorf("download dir: %w", err)
+			}
+		} else {
+			if err := Download(fs, srcPath, dstPath); err != nil {
+				return fmt.Errorf("download file in dir: %w", err)
+			}
+		}
+	}
+	return nil
+}