/* -*- mode: C++; indent-tabs-mode: nil; -*-

 *

 * This file is a part of LEMON, a generic C++ optimization library.

 *

 * Copyright (C) 2003-2009

 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

 * (Egervary Research Group on Combinatorial Optimization, EGRES).

 *

 * Permission to use, modify and distribute this software is granted

 * provided that this copyright notice appears in all copies. For

 * precise terms see the accompanying LICENSE file.

 *

 * This software is provided "AS IS" with no warranty of any kind,

 * express or implied, and with no claim as to its suitability for any

 * purpose.

 *

 */

#ifndef LEMON_COUNTER_H

#define LEMON_COUNTER_H

#include <string>

#include <iostream>

///\ingroup timecount

///\file

///\brief Tools for counting steps and events

namespace lemon

{

  template<class P> class _NoSubCounter;

  template<class P>

  class _SubCounter

  {

    P &_parent;

    std::string _title;

    std::ostream &_os;

    int count;

  public:

    typedef _SubCounter<_SubCounter<P> > SubCounter;

    typedef _NoSubCounter<_SubCounter<P> > NoSubCounter;

    _SubCounter(P &parent)

      : _parent(parent), _title(), _os(std::cerr), count(0) {}

    _SubCounter(P &parent,std::string title,std::ostream &os=std::cerr)

      : _parent(parent), _title(title), _os(os), count(0) {}

    _SubCounter(P &parent,const char *title,std::ostream &os=std::cerr)

      : _parent(parent), _title(title), _os(os), count(0) {}

    ~_SubCounter() {

      _os << _title << count <<std::endl;

      _parent+=count;

    }

    _SubCounter &operator++() { count++; return *this;}

    int operator++(int) { return count++; }

    _SubCounter &operator--() { count--; return *this;}

    int operator--(int) { return count--; }

    _SubCounter &operator+=(int c) { count+=c; return *this;}

    _SubCounter &operator-=(int c) { count-=c; return *this;}

    operator int() {return count;}

  };

  template<class P>

  class _NoSubCounter

  {

    P &_parent;

  public:

    typedef _NoSubCounter<_NoSubCounter<P> > SubCounter;

    typedef _NoSubCounter<_NoSubCounter<P> > NoSubCounter;

    _NoSubCounter(P &parent) :_parent(parent) {}

    _NoSubCounter(P &parent,std::string,std::ostream &)

      :_parent(parent) {}

    _NoSubCounter(P &parent,std::string)

      :_parent(parent) {}

    _NoSubCounter(P &parent,const char *,std::ostream &)

      :_parent(parent) {}

    _NoSubCounter(P &parent,const char *)

      :_parent(parent) {}

    ~_NoSubCounter() {}

    _NoSubCounter &operator++() { ++_parent; return *this;}

    int operator++(int) { _parent++; return 0;}

    _NoSubCounter &operator--() { --_parent; return *this;}

    int operator--(int) { _parent--; return 0;}

    _NoSubCounter &operator+=(int c) { _parent+=c; return *this;}

    _NoSubCounter &operator-=(int c) { _parent-=c; return *this;}

    operator int() {return 0;}

  };

  /// \addtogroup timecount

  /// @{

  /// A counter class

  /// This class makes it easier to count certain events (e.g. for debug

  /// reasons).

  /// You can increment or decrement the counter using \c operator++,

  /// \c operator--, \c operator+= and \c operator-=. You can also

  /// define subcounters for the different phases of the algorithm or

  /// for different types of operations.

  /// A report containing the given title and the value of the counter

  /// is automatically printed on destruction.

  ///

  /// The following example shows the usage of counters and subcounters.

  /// \code

  /// // Bubble sort

  /// std::vector<T> v;

  /// ...

  /// Counter op("Operations: ");

  /// Counter::SubCounter as(op, "Assignments: ");

  /// Counter::SubCounter co(op, "Comparisons: ");

  /// for (int i = v.size()-1; i > 0; --i) {

  ///   for (int j = 0; j < i; ++j) {

  ///     if (v[j] > v[j+1]) {

  ///       T tmp = v[j];

  ///       v[j] = v[j+1];

  ///       v[j+1] = tmp;

  ///       as += 3;          // three assignments

  ///     }

  ///     ++co;               // one comparison

  ///   }

  /// }

  /// \endcode

  ///

  /// This code prints out something like that:

  /// \code

  /// Comparisons: 45

  /// Assignments: 57

  /// Operations: 102

  /// \endcode

  ///

  /// \sa NoCounter

  class Counter

  {

    std::string _title;

    std::ostream &_os;

    int count;

  public:

    /// SubCounter class

    /// This class can be used to setup subcounters for a \ref Counter

    /// to have finer reports. A subcounter provides exactly the same

    /// operations as the main \ref Counter, but it also increments and

    /// decrements the value of its parent.

    /// Subcounters can also have subcounters.

    ///

    /// The parent counter must be given as the first parameter of the

    /// constructor. Apart from that a title and an \c ostream object

    /// can also be given just like for the main \ref Counter.

    ///

    /// A report containing the given title and the value of the

    /// subcounter is automatically printed on destruction. If you

    /// would like to turn off this report, use \ref NoSubCounter

    /// instead.

    ///

    /// \sa NoSubCounter

    typedef _SubCounter<Counter> SubCounter;

    /// SubCounter class without printing report on destruction

    /// This class can be used to setup subcounters for a \ref Counter.

    /// It is the same as \ref SubCounter but it does not print report

    /// on destruction. (It modifies the value of its parent, so 'No'

    /// only means 'do not print'.)

    ///

    /// Replacing \ref SubCounter "SubCounter"s with \ref NoSubCounter

    /// "NoSubCounter"s makes it possible to turn off reporting

    /// subcounter values without actually removing the definitions

    /// and the increment or decrement operators.

    ///

    /// \sa SubCounter

    typedef _NoSubCounter<Counter> NoSubCounter;

    /// Constructor.

    Counter() : _title(), _os(std::cerr), count(0) {}

    /// Constructor.

    Counter(std::string title,std::ostream &os=std::cerr)

      : _title(title), _os(os), count(0) {}

    /// Constructor.

    Counter(const char *title,std::ostream &os=std::cerr)

      : _title(title), _os(os), count(0) {}

    /// Destructor. Prints the given title and the value of the counter.

    ~Counter() {

      _os << _title << count <<std::endl;

    }

    ///\e

    Counter &operator++() { count++; return *this;}

    ///\e

    int operator++(int) { return count++;}

    ///\e

    Counter &operator--() { count--; return *this;}

    ///\e

    int operator--(int) { return count--;}

    ///\e

    Counter &operator+=(int c) { count+=c; return *this;}

    ///\e

    Counter &operator-=(int c) { count-=c; return *this;}

    /// Resets the counter to the given value.

    /// Resets the counter to the given value.

    /// \note This function does not reset the values of

    /// \ref SubCounter "SubCounter"s but it resets \ref NoSubCounter

    /// "NoSubCounter"s along with the main counter.

    void reset(int c=0) {count=c;}

    /// Returns the value of the counter.

    operator int() {return count;}

  };

  /// 'Do nothing' version of Counter.

  /// This class can be used in the same way as \ref Counter, but it

  /// does not count at all and does not print report on destruction.

  ///

  /// Replacing a \ref Counter with a \ref NoCounter makes it possible

  /// to turn off all counting and reporting (SubCounters should also

  /// be replaced with NoSubCounters), so it does not affect the

  /// efficiency of the program at all.

  ///

  /// \sa Counter

  class NoCounter

  {

  public:

    typedef _NoSubCounter<NoCounter> SubCounter;

    typedef _NoSubCounter<NoCounter> NoSubCounter;

    NoCounter() {}

    NoCounter(std::string,std::ostream &) {}

    NoCounter(const char *,std::ostream &) {}

    NoCounter(std::string) {}

    NoCounter(const char *) {}

    NoCounter &operator++() { return *this; }

    int operator++(int) { return 0; }

    NoCounter &operator--() { return *this; }

    int operator--(int) { return 0; }

    NoCounter &operator+=(int) { return *this;}

    NoCounter &operator-=(int) { return *this;}

    void reset(int) {}

    void reset() {}

    operator int() {return 0;}

  };

  ///@}

}

#endif