/*
 * RVersionInfo.cpp
 *
 * Copyright (C) 2009-19 by RStudio, PBC
 *
 * Unless you have received this program directly from RStudio pursuant
 * to the terms of a commercial license agreement with RStudio, then
 * this program is licensed to you under the terms of version 3 of the
 * GNU Affero General Public License. This program is distributed WITHOUT
 * ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING THOSE OF NON-INFRINGEMENT,
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Please refer to the
 * AGPL (http://www.gnu.org/licenses/agpl-3.0.txt) for more details.
 *
 */

#include <r/RVersionInfo.hpp>
#include <r/RExec.hpp>

#include <shared_core/Error.hpp>

using namespace rstudio::core;
using namespace rstudio::core::r_util;

namespace rstudio {
namespace r {
namespace version_info {

// Returns a representation of the current version of R
RVersionNumber currentRVersion()
{
   // Cached R version number; this can't change during the session so it's safe to keep a copy
   static RVersionNumber current;
   if (current.empty())
   {
      // No cache; ask R for its current version
      std::string currentRVersion;
      Error error = exec::RFunction(".rs.rVersionString").call(&currentRVersion);
      if (!error)
         current = RVersionNumber::parse(currentRVersion);
   }
   return current;
}

} // namespace version_info
} // namespace r
} // namespace rstudio