/* 
    abCOpSubtr.c
        By: Jeremy Rand
 */


#include <stdio.h>

#include "abCError.h"
#include "abCStack.h"

#include "expr/abCExpr.h"
#include "expr/abCExpReal.h"
#include "expr/abCExprInt.h"

#include "ops/abCOp.h"
#include "ops/abCOpSubtr.h"


#define SUB_NAME "-"


static void subtrExecute(void);


void abCalcOpSubtrInit(void)
{
    abCalcOpRegister(SUB_NAME, subtrExecute);
}


void subtrExecute(void)
{
    abCalcExpr result;
    char expr1Real = 0;
    char expr2Real = 0;
    AB_CALC_OP_TWO_ARGS(SUB_NAME);

    if (expr1->type == abCalcExprTypeReal) {
        expr1Real = 1;
    } else if (expr1->type != abCalcExprTypeInt) {
        abCalcRaiseError(abCalcBadArgTypeError, SUB_NAME);
        return;
    }

    if (expr2->type == abCalcExprTypeReal) {
        expr2Real = 1;
    } else if (expr2->type != abCalcExprTypeInt) {
        abCalcRaiseError(abCalcBadArgTypeError, SUB_NAME);
        return;
    }

    if ((expr1Real) && (expr2Real)) {
        abCalcExprRealSet(&result, expr2->u.real - expr1->u.real);
    } else {
        if (expr1Real) {
            abCalcExprIntSet(&result, expr2->u.integer - (abCalcIntType)expr1->u.real);
        } else if (expr2Real) {
            abCalcExprIntSet(&result, (abCalcIntType)expr2->u.real - expr1->u.integer);
        } else {
            abCalcExprIntSet(&result, expr2->u.integer - expr1->u.integer);
        }
    }

    abCalcStackExprPop(NULL);
    abCalcStackExprPop(NULL);
    abCalcStackExprPush(&result);
}