tools: refactor nfd-status

refs #3658

Change-Id: Ia347074bea802eba5f539208e276e849a60db8a4
diff --git a/tools/nfd-status/format-helpers.cpp b/tools/nfd-status/format-helpers.cpp
new file mode 100644
index 0000000..c7e595b
--- /dev/null
+++ b/tools/nfd-status/format-helpers.cpp
@@ -0,0 +1,128 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2016,  Regents of the University of California,
+ *                           Arizona Board of Regents,
+ *                           Colorado State University,
+ *                           University Pierre & Marie Curie, Sorbonne University,
+ *                           Washington University in St. Louis,
+ *                           Beijing Institute of Technology,
+ *                           The University of Memphis.
+ *
+ * This file is part of NFD (Named Data Networking Forwarding Daemon).
+ * See AUTHORS.md for complete list of NFD authors and contributors.
+ *
+ * NFD 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.
+ *
+ * NFD 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 a copy of the GNU General Public License along with
+ * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "format-helpers.hpp"
+
+namespace nfd {
+namespace tools {
+namespace nfd_status {
+
+namespace xml {
+
+void
+printHeader(std::ostream& os)
+{
+  os << "<?xml version=\"1.0\"?>"
+     << "<nfdStatus xmlns=\"ndn:/localhost/nfd/status/1\">";
+}
+
+void
+printFooter(std::ostream& os)
+{
+  os << "</nfdStatus>";
+}
+
+std::ostream&
+operator<<(std::ostream& os, const Text& text)
+{
+  for (char ch : text.s) {
+    switch (ch) {
+      case '"':
+        os << "&quot;";
+        break;
+      case '&':
+        os << "&amp;";
+        break;
+      case '\'':
+        os << "&apos;";
+        break;
+      case '<':
+        os << "&lt;";
+        break;
+      case '>':
+        os << "&gt;";
+        break;
+      default:
+        os << ch;
+        break;
+    }
+  }
+  return os;
+}
+
+std::string
+formatSeconds(time::seconds d)
+{
+  return "PT" + to_string(d.count()) + "S";
+}
+
+std::string
+formatTimestamp(time::system_clock::TimePoint t)
+{
+  return time::toString(t, "%Y-%m-%dT%H:%M:%S%F");
+}
+
+} // namespace xml
+
+namespace text {
+
+Separator::Separator(const std::string& first, const std::string& subsequent)
+  : m_first(first)
+  , m_subsequent(subsequent)
+  , m_count(0)
+{
+}
+
+Separator::Separator(const std::string& subsequent)
+  : Separator("", subsequent)
+{
+}
+
+std::ostream&
+operator<<(std::ostream& os, Separator& sep)
+{
+  if (++sep.m_count == 1) {
+    return os << sep.m_first;
+  }
+  return os << sep.m_subsequent;
+}
+
+std::string
+formatSeconds(time::seconds d, bool isLong)
+{
+  return to_string(d.count()) + (isLong ? " seconds" : "s");
+}
+
+std::string
+formatTimestamp(time::system_clock::TimePoint t)
+{
+  return time::toIsoString(t);
+}
+
+} // namespace text
+
+} // namespace nfd_status
+} // namespace tools
+} // namespace nfd