/* -*- C++ -*-

  *

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

  *

  * Copyright (C) 2003-2008

  * 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 however 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