/** ==========================================================================
 * 2013 by KjellKod.cc. This is PUBLIC DOMAIN to use at your own risk and comes
 * with no warranties. This code is yours to share, use and modify with no
 * strings attached and no restrictions or obligations.
 *
 * For more information see g3log/LICENSE or refer refer to http://unlicense.org
 * ============================================================================*/

#include "g3log/filesink.hpp"
#include "filesinkhelper.ipp"
#include <cassert>

namespace g3 {
   using namespace internal;


   FileSink::FileSink(const std::string &log_prefix, const std::string &log_directory, const std::string& logger_id)
      : _log_file_with_path(log_directory)
      , _log_prefix_backup(log_prefix)
      , _outptr(new std::ofstream)
   {
      _log_prefix_backup = prefixSanityFix(log_prefix);
      if (!isValidFilename(_log_prefix_backup)) {
         std::cerr << "g3log: forced abort due to illegal log prefix [" << log_prefix << "]" << std::endl;
         abort();
      }

      std::string file_name = createLogFileName(_log_prefix_backup, logger_id);
      _log_file_with_path = pathSanityFix(_log_file_with_path, file_name);
      _outptr = createLogFile(_log_file_with_path);

      if (!_outptr) {
         std::cerr << "Cannot write log file to location, attempting current directory" << std::endl;
         _log_file_with_path = "./" + file_name;
         _outptr = createLogFile(_log_file_with_path);
      }
      assert(_outptr && "cannot open log file at startup");
      addLogFileHeader();
   }


   FileSink::~FileSink() {
      std::string exit_msg {"g3log g3FileSink shutdown at: "};
      exit_msg.append(localtime_formatted(systemtime_now(), internal::time_formatted)).append({"\n"});
      filestream() << exit_msg << std::flush;

      exit_msg.append({"Log file at: ["}).append(_log_file_with_path).append({"]\n"});
      std::cerr << exit_msg << std::flush;
   }

   // The actual log receiving function
   void FileSink::fileWrite(LogMessageMover message) {
      std::ofstream &out(filestream());
      out << message.get().toString() << std::flush;
   }

   std::string FileSink::changeLogFile(const std::string &directory, const std::string &logger_id) {

      auto now = g3::systemtime_now();
      auto now_formatted = g3::localtime_formatted(now, {internal::date_formatted + " " + internal::time_formatted});

      std::string file_name = createLogFileName(_log_prefix_backup, logger_id);
      std::string prospect_log = directory + file_name;
      std::unique_ptr<std::ofstream> log_stream = createLogFile(prospect_log);
      if (nullptr == log_stream) {
         filestream() << "\n" << now_formatted << " Unable to change log file. Illegal filename or busy? Unsuccessful log name was: " << prospect_log;
         return {}; // no success
      }

      addLogFileHeader();
      std::ostringstream ss_change;
      ss_change << "\n\tChanging log file from : " << _log_file_with_path;
      ss_change << "\n\tto new location: " << prospect_log << "\n";
      filestream() << now_formatted << ss_change.str();
      ss_change.str("");

      std::string old_log = _log_file_with_path;
      _log_file_with_path = prospect_log;
      _outptr = std::move(log_stream);
      ss_change << "\n\tNew log file. The previous log file was at: ";
      ss_change << old_log;
      filestream() << now_formatted << ss_change.str();
      return _log_file_with_path;
   }
   std::string FileSink::fileName() {
      return _log_file_with_path;
   }
   void FileSink::addLogFileHeader() {
      filestream() << header();
   }

} // g3