#include "cs_mex.h"
/* cs_add: sparse matrix addition */

#ifndef NCOMPLEX
static cs_complex_t get_complex (const mxArray *a)
{
    cs_complex_t s = mxGetScalar (a) ;
    if (mxIsComplex (a))
    {
	double *z = mxGetPi (a) ;
	s += I * z [0] ;
    }
    return (s) ;
}
#endif

void mexFunction
(
    int nargout,
    mxArray *pargout [ ],
    int nargin,
    const mxArray *pargin [ ]
)
{
    if (nargout > 1 || nargin < 2 || nargin > 4)
    {
	mexErrMsgTxt ("Usage: C = cs_add(A,B,alpha,beta)") ;
    }
    if (mxIsComplex (pargin [0]) || mxIsComplex (pargin [1])
	|| (nargin > 2 && mxIsComplex (pargin [2]))
	|| (nargin > 3 && mxIsComplex (pargin [3])))
    {
#ifndef NCOMPLEX
	cs_complex_t alpha, beta ;
	cs_cl Amatrix, Bmatrix, *A, *B, *C, *D ;
	A = cs_cl_mex_get_sparse (&Amatrix, 0, pargin [0]) ;	/* get A */
	B = cs_cl_mex_get_sparse (&Bmatrix, 0, pargin [1]) ;	/* get B */
	alpha = (nargin < 3) ? 1 : get_complex (pargin [2]) ;   /* get alpha */
	beta  = (nargin < 4) ? 1 : get_complex (pargin [3]) ;   /* get beta */
	C = cs_cl_add (A,B,alpha,beta) ;    /* C = alpha*A + beta *B */
	cs_cl_dropzeros (C) ;		/* drop zeros */
	D = cs_cl_transpose (C, 1) ;	/* sort result via double transpose */
	cs_cl_spfree (C) ;
	C = cs_cl_transpose (D, 1) ;
	cs_cl_spfree (D) ;
	pargout [0] = cs_cl_mex_put_sparse (&C) ;	/* return C */
#else
	mexErrMsgTxt ("complex matrices not supported") ;
#endif
    }
    else
    {
	double alpha, beta ;
	cs_dl Amatrix, Bmatrix, *A, *B, *C, *D ;
	A = cs_dl_mex_get_sparse (&Amatrix, 0, 1, pargin [0]) ;    /* get A */
	B = cs_dl_mex_get_sparse (&Bmatrix, 0, 1, pargin [1]) ;    /* get B */
	alpha = (nargin < 3) ? 1 : mxGetScalar (pargin [2]) ;   /* get alpha */
	beta  = (nargin < 4) ? 1 : mxGetScalar (pargin [3]) ;   /* get beta */
	C = cs_dl_add (A,B,alpha,beta) ;	/* C = alpha*A + beta *B */
	cs_dl_dropzeros (C) ;		/* drop zeros */
	D = cs_dl_transpose (C, 1) ;	/* sort result via double transpose */
	cs_dl_spfree (C) ;
	C = cs_dl_transpose (D, 1) ;
	cs_dl_spfree (D) ;
	pargout [0] = cs_dl_mex_put_sparse (&C) ;	/* return C */
    }
}
