/*
 * (C) Copyright 1996-2016 ECMWF.
 * 
 * This software is licensed under the terms of the Apache Licence Version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0. 
 * In applying this licence, ECMWF does not waive the privileges and immunities 
 * granted to it by virtue of its status as an intergovernmental organisation nor
 * does it submit to any jurisdiction.
 */

/*! \file 
.cc
    \brief Implementation of the Template class CountSelectionType.
    
    Magics Team - ECMWF 2004
    
    Started: Tue 9-Mar-2004
    
    Changes:
    
*/

 
#include "CountSelectionType.h"
#include "PointsHandler.h"
#include "UserPoint.h"

using namespace magics;


CountSelectionType::CountSelectionType() 
{
}


void CountSelectionType::calculate(double min, double max, bool)
{
        clear();
        double maxi = (max_ >  1000000000) ? max : max_;
        double mini = (min_ < -1000000000) ? min : min_;
        int i = 0;

        i += ( max_ >  1000000000) ? 1 : 0;
        i += ( min_ < -1000000000) ? 1 : 0;
        
        
        
        double nb = levelCount_-1;
        if ( same(maxi,mini) )  {
        	push_back(mini);
        	return;
        }
        double step = (maxi - mini)/nb;
        double toleranceProportion = (double)tolerance_ / (double)(levelCount_ + 1 + i);  // tolerance as a proportion of the number of levels
                                     // we add 'i' here because it will be subtracted at the end (because this is the number
                                     // of levels we will not actually plot, ie the min/max contours).
        if ( same(step,0) ) {
        	// Only one isoline!
        	push_back(mini);
        	return;
        } 


        // get the log of the step as an integer
        int log = log10(step);
        if (step < 1) log -= 1;

        double inc;
        double istep = pow(10., log);
        double step0to10 = step/istep;
        double stepTolerance = step0to10 * toleranceProportion * 0.95;


        // we now have step0to10 as a number from 0 to 10, so we can
        // set it to the nearest 'nice' number for contouring, with
        // some bias for numbers such as 10 and 5.

             if (fabs (step0to10 - 10) < stepTolerance) inc = 10;
        else if (fabs (step0to10 -  5) < stepTolerance) inc =  5;
        else
        {
            inc = static_cast<int>(step0to10 + 0.5);  // round to nearest integer


            // will using this number be within our tolerance?
            // i.e. will this give us approx the right number of contours?
            // if not, then make an adjustment and test again. Do this
            // until the adjustments get too small (avoid infinite loops!)

            double diffFromIdeal = step0to10 - inc;
            double incAdjustment = 0.5;

            while (fabs(diffFromIdeal) > stepTolerance && incAdjustment > 0.1)
            {
                if (diffFromIdeal > stepTolerance)
                {
                    inc += incAdjustment;
                }
                else if (diffFromIdeal < -stepTolerance)
                {
                    inc -= incAdjustment;
                }

                diffFromIdeal = step0to10 - inc;
                incAdjustment /= 2.0;
            }
        }

        inc *= istep;  // convert back into proper range


        double first = floor(mini/inc)*inc;
  
        while ( first > mini ) 
        	first -=inc;
        
        push_back(mini);
        first += inc;
        double epsilon = inc/10000.0;
        while ( same(epsilon, 0) ) {
            
            epsilon *= 10;
            EPSILON /= 10;
        }

       
        for (double val = first; val < maxi; val += inc) {         
            // special case - if the value is close to zero then set it to precisely zero to avoid later formatting issues
            if (fabs(val) < epsilon)
                push_back(0.0);
            else if ( same(val, maxi) )
            		push_back(maxi);
            else
            	push_back(val);
        }
	
        if ( maxi != back() )
        	push_back(maxi);
        int si = static_cast<int>(size());


        // last resort - if we have too many/few contours, then just do a 'blind' division
        // so as to ensure the correct number, even if they are not nice

        if ( si - i < levelCount_ - tolerance_ || si - i > levelCount_ + tolerance_ ) {
            MagLog::debug() << "Not using nice levels[" << levelCount_ << ", " << tolerance_ << "]-->" << size()  << endl;
            clear();
            step = (maxi - mini)/(levelCount_-1);
            double val = mini;
            while ( 1 ) {
                push_back(val);
                if ( same(val, maxi) || val > maxi) break; 
                val += step;
            } 
            MagLog::debug() << "New size-->" << size() << endl;
        } 
  
        MagLog::debug() << "count=" << levelCount_ << ", tolerance=" << tolerance_ << ", result=" << size() << endl;

        ostringstream level;
        for (const_iterator l = begin(); l != end(); ++l) 
            level << *l << " ";
 
        MagLog::debug() << level.str() << endl;
}


CountSelectionType::~CountSelectionType() 
{
}

/*!
 Class information are given to the output-stream.
*/
void CountSelectionType::print(ostream& out)  const
{
	out << "CountSelectionType[";
	out << "]";
}

void CountSelectionType::set(const LevelSelectionInterface& from) 
{
    levelCount_ = from.getCount();
    tolerance_ = from.getTolerance();
    reference_ = from.getReference();
    min_ = from.getMin();
    max_ = from.getMax();
}
