/**
    @class EffPointingCutoff.cpp
    @author Greg Paxton
    @creation date 9/18/2009

	$Date:$
    $Revision:$

    @copyright
     (©) Copyright 2009 by GATS Inc.
     11864 Canon Blvd., Suite 101, Newport News, VA 23606

     All Rights Reserved. No part of this software or publication may be
     reproduced, stored in a retrieval system, or transmitted, in any form
     or by any means, electronic, mechanical, photocopying, recording, or
     otherwise without the prior written permission of GATS Inc.
        
    @brief Determines the Pointing Correction Cutoff index
*/

#include <stdexcept>
#include "EffPointingCutoff.h"
#include <iostream>

using namespace std;

void EffPointingCutoff::operator()(valarray<double> const &time, valarray<double> const &lockdown, double & value, long & index)
{
	long i = 0;
	double dx = 0.0;
	double a = 0.0;
	index = 0;

	if (cutoffTime < time.min() || cutoffTime > time.max())
	{
		std::cout << "EffPointingCutoff: time min is " << time.min() << " time max is " << time.max() << " cutoffTime is " << cutoffTime << std::endl;
    	throw runtime_error("\nEffPointingCutoff:: cutoff time out of range");
	}
    
	if (mode)
	{
    	for(i = 0; i < (long)(time.size()); i++)
       	{
       		if (time[i] >= cutoffTime)
			{
				index = i;
			}
       	}

        if (index == (long)(time.size() - 1))
		{
			value = lockdown[index];
			std::cerr << "\nEffPointingCutoff: Cutoff time is equal to the end of the time array\n" << std::endl;
			return;
		}
	}
	else
	{
    	for(i = 0; i < (long)(time.size()); i++)
    	//for(i = time.size() - 1; i >= 0 ; i--)
       	{
       		if (time[i] <= cutoffTime)
			{
				index = i;
			}
		}

        if (index == (long)(time.size() - 1))
		{
			value = lockdown[index];
			std::cerr << "\nEffPointingCutoff: Cutoff time is equal to the end of the time array\n" << std::endl;
			return;
		}
    }

	// Interpolate the lockdown position from the time grid at the cutoff time.
	dx = time[index+1] - time[index];
	if (dx == 0.0)
	{
		value = (lockdown[index] + lockdown[index+1])/2;
	}
	else
	{
		a = (cutoffTime - time[index]) / dx;
		value = lockdown[index] + a * (lockdown[index+1] - lockdown[index]);
	}
}