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#ifndef __RVLALG_SCALAR_TERMINATOR
#define __RVLALG_SCALAR_TERMINATOR

#include "alg.hh"
#include "functional.hh"
#include "except.hh"

/**  scalarterm.H
     All Terminators which watch the behavior of a scalar or integer
     to determine when to stop.

*/

namespace RVLAlg {

  /** This terminator contains an internal integer which it increments when called.
      After incrementing, the integer is compared to a maximum value.
      Stops when \f$count \geq maxcount\f$.
  */
class CountTerminator: public Terminator {
public:

  /** Initializes count to zero.
      When query is called, increments count by 1 and then tests to see if maxcount 
      has been reached.

      returns true when count == maxcount
      
              false when count < maxcount
  */
  CountTerminator( int maxcount ) : mc(maxcount), count(0), i(1) {}

  /** Initializes count to init.
      When query is called, increments count by inc and then tests to see if maxcount 
      has been reached.

      returns true when count >= maxcount

              false when count < maxcount

	      throws an error if inc is moving count away from maxcount
  */
  CountTerminator( int init, int maxcount, int inc ) 
    : mc(maxcount), count(init), i(inc) {
    if ( inc <= 0 ) {
      RVL::RVLException e; e << "Error in CountTerminator constructor: parameters cause infinite loop";
      throw e;
    }
  }
  
  ~CountTerminator() {}

  virtual bool query() {
    count += i;
    return (count >= mc );
  }

  int getCount() { return count; }

protected:
  int mc;
  int count;
  int i;

private:

  CountTerminator();
  CountTerminator(CountTerminator const &);
};

/** Terminator which takes a scalar and a maximum value.

    STOP: \f$x > maxval\f$
*/

template<class Scalar>
class MaxTerminator: public Terminator {
public:
  MaxTerminator(const Scalar & tx, Scalar maxval) : x(tx), mv(maxval) {}
  
  virtual bool query() {
    return (x > mv);
  }

protected:
  const Scalar & x;
  Scalar mv;
};

/** Terminator which takes a scalar and a minimum value.

    STOP: \f$x < minval\f$
*/

template<class Scalar>
class MinTerminator: public Terminator {
public:
  MinTerminator(const Scalar & tx, Scalar minval) : x(tx), mv(minval) {}
  
  virtual bool query() {
    cout<<"   MinTerminator: test scalar = "<<x<<" threshold = "<<mv<<endl;
    return (x < mv);
  }

protected:
  const Scalar & x;
  Scalar mv;
};

/** Terminator which takes a scalar and a minimum value.

    STOP: \f$x < minval\f$
*/
  
  template<class Scalar>
  class MinTerminatorFE: public Terminator {
  public:
    MinTerminatorFE(RVL::FunctionalEvaluation<Scalar> & _fx, Scalar minval) 
      : fx(_fx), mv(minval) {}
    
    virtual bool query() {
      Scalar x = fx.getValue();
      cout<<"   MinTerminator: test scalar = "<<x<<" threshold = "<<mv<<endl;
      return (x < mv);
    }
    
  protected:
    Scalar mv;
  private:
    RVL::FunctionalEvaluation<Scalar> & fx;
  };


}

#endif