/*  snmcopyv.cpp  by K.Tsuru  */
// function ID = 104
/****************************************************************
SNumber class
It copies various values, FigBlock figure,etc.
If cs = COPY, it sets figure = a.figure only.This is used in the copy
constructor of te derived class.
If cs = SUBS, it allocates memory or adjusts the size of figure.
This is used in the substitution operators.
*****************************************************************/
#ifndef SN_H
#include "sn.h"
#endif

#ifndef NDEBUG
static const char* func = "CopyValue";
#endif

void SNumber::CopyValue(const SNumber& a, int cs)
{
    if(this == &a) return;  //For a = a.

    aHead = a.aHead;    aTail = a.aTail;    type  = a.type;

// Called by copy constructor.
    if(cs == COPY){
        figure = a.figure;
#ifndef NDEBUG
assert(figure.Error() == figure.NORMAL);
#endif
        sign = a.sign;
        return;
    }
    if(a.sign == ZERO){ // a = 0; It may be able to minimize the size.
                        //If Sign() is used UNDEC_VALUE error occures.
//Do not use figure.size(minArraySize,0); It may be cutDown == DISABLE.
        SetZero();      return;
    }

//It prohibits to substitute an unsubstantial object for a substantial one.
    if( (a.figure.size() == 0) || (a.sign == UNDECIDED) ){
        if(figure.size() > 0) SetError(UNDEC_VALUE, "", 104);
        return;     // a.figure.size() = figure.size() = 0 is OK.
    }
//  sign = a.sign;      // Execute in last line.

/********************************************************
When CutDown() == DISABLE, do not reduce the size of this.
See Lpow() function for example.
*********************************************************/
    uint alc_sz;

    if(CutDown() == DISABLE) alc_sz = max(a.figure.size(), figure.size());
    else alc_sz = a.aHead +1;
    valloc(alc_sz, -1); //It does not copy and allocates the memory. sign = UNDECIDED;
    uint max_sz = SNMaxSize(type), n_copy;

    if(type & REAL){                // real type
        n_copy = min(figure.size(), a.aHead+1);
    //It considers the substitution of longer number e.g. E()
    //after reducing the number of effective figures.
        if(n_copy > max_sz) n_copy = max_sz;
    } else n_copy = a.aHead + 1;    // integer type

//It copies the lower part of a.
    memcpy(figure.Elements(), a.ReadFigures() , n_copy*sizeof(fType) );
    figure.clear(n_copy);   //It fills the upper part with zeros. figure[i]=0 for i>aHead
    sign = a.sign;          // sign : change UNDECIDED to a.sign

    if(aHead >= max_sz){//The number of effective figures was reduced by calling SetEffFig().
        CheckArray(-104);//It rarely occures.
    }
//check errors
#ifndef NDEBUG
    int sc = (sign == UNDECIDED) || (sign == ZERO) || (sign == PLUS) || (sign == MINUS);
    if(!sc){
        SetError(FATAL, func, (int)sign);
    }
    if(figure.Error() != figure.NORMAL) SetError(FATAL, func, 104);
    if( aHead >= figure.size() ) SetError(FATAL, func, (int)aHead);
    if( aTail > aHead ){
        SetError(FATAL, func, (int)aTail);
    }
#endif
}