/*    This file is part of the Gudhi Library. The Gudhi library 
 *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
 *    library for computational topology.
 *
 *    Author(s):       David Salinas
 *
 *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
 *
 *    This program 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.
 *
 *    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef CLOCK_H_
#define CLOCK_H_

#include <boost/date_time/posix_time/posix_time.hpp>

#include <string>

class Clock {
 public:
  Clock() : end_called(false) {
    startTime = boost::posix_time::microsec_clock::local_time();
  }

  Clock(const std::string& msg_) {
    end_called = false;
    begin();
    msg = msg_;
  }

  void begin() const {
    end_called = false;
    startTime = boost::posix_time::microsec_clock::local_time();
  }

  void end() const {
    end_called = true;
    endTime = boost::posix_time::microsec_clock::local_time();
  }

  void print() const {
    std::cout << *this << std::endl;
  }

  friend std::ostream& operator<<(std::ostream& stream, const Clock& clock) {
    if (!clock.end_called)
      clock.end();

    if (!clock.end_called) {
      stream << "end not called";
    } else {
      stream << clock.msg << ":" << clock.num_seconds() << "s";
    }
    return stream;
  }

  double num_seconds() const {
    if (!end_called) return -1;
    return (endTime - startTime).total_milliseconds() / 1000.;
  }

 private:
  mutable boost::posix_time::ptime startTime, endTime;
  mutable bool end_called;
  std::string msg;
};

#endif  // CLOCK_H_