use enum class for status

Change-Id: Iaba23e0754335a7fecec2d6c4b3446988b2fd9d0
diff --git a/src/ndncert-common.cpp b/src/ndncert-common.cpp
new file mode 100644
index 0000000..0a6c994
--- /dev/null
+++ b/src/ndncert-common.cpp
@@ -0,0 +1,49 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2017-2020, Regents of the University of California.
+ *
+ * This file is part of ndncert, a certificate management system based on NDN.
+ *
+ * ndncert is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * ndncert is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License along with
+ * ndncert, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndncert authors and contributors.
+ */
+
+#include "ndncert-common.hpp"
+
+namespace ndn {
+namespace ndncert {
+
+std::string statusToString(Status status) {
+  switch (status)
+  {
+  case Status::BEFORE_CHALLENGE:
+    return "Before challenge";
+  case Status::CHALLENGE:
+    return "In challenge";
+  case Status::PENDING:
+    return "Pending after challenge";
+  case Status::SUCCESS:
+    return "Success";
+  case Status::FAILURE:
+    return "Failure";
+  case Status::NOT_STARTED:
+    return "Not started";
+  case Status::ENDED:
+    return "Ended";
+  default:
+    return "Unrecognized status";
+  }
+}
+
+}  // namespace ndncert
+}  // namespace ndn