/*! \file
Copyright (c) 2003, The Regents of the University of California, through
Lawrence Berkeley National Laboratory (subject to receipt of any required 
approvals from U.S. Dept. of Energy) 

All rights reserved. 

The source code is distributed under BSD license, see the file License.txt
at the top-level directory.
*/
/*
 * -- SuperLU routine (version 4.2) --
 * Univ. of California Berkeley, Xerox Palo Alto Research Center,
 * and Lawrence Berkeley National Lab.
 * October 15, 2003
 *
 * Modified: September 25, 2011,  compatible with 64-bit integer in R2006b
 */
#include <stdio.h>
#include "mex.h"
#include "slu_ddefs.h"

#define  MatlabMatrix mxArray

#if 0   /* V4 */
#define  MatlabMatrix Matrix
#endif


/* Aliases for input and output arguments */
#define A_in		prhs[0]
#define b_in    	prhs[1]
#define Pc_in		prhs[2]
#define x_out		plhs[0]

#define verbose (SPUMONI>0)
#define babble  (SPUMONI>1)
#define burble  (SPUMONI>2)

void mexFunction(
    int          nlhs,           /* number of expected outputs */
    MatlabMatrix *plhs[],        /* matrix pointer array returning outputs */
    int          nrhs,           /* number of inputs */
    const MatlabMatrix *prhs[]   /* matrix pointer array for inputs. */
#if 0 /* V4 */
    MatlabMatrix *prhs[]         /* matrix pointer array for inputs */
#endif
    )
{
    int SPUMONI;             /* ... as should the sparse monitor flag */
    double FlopsInSuperLU;   /* ... as should the flop counter. */
    extern flops_t LUFactFlops(SuperLUStat_t*);
    extern flops_t LUSolveFlops(SuperLUStat_t*);
    
    /* Arguments to dgssv(). */
    SuperMatrix A;
    SuperMatrix B;
    SuperMatrix L, U;
    int	   	m, n, nnz;
    int         numrhs;
    double 	*vb, *x;
    double      *val;
    int       	*rowind;
    int		*colptr;
    int    	*perm_r, *perm_c;
    mwSize      *perm_c_64;
    mwSize      *rowind_64;
    mwSize      *colptr_64;
    int		info;
    MatlabMatrix *X, *Y;            /* args to calls back to Matlab */
    int         i, mexerr;
    superlu_options_t options;
    SuperLUStat_t stat;

    /* Check number of arguments passed from Matlab. */
    if (nrhs != 3) {
	mexErrMsgTxt("LUSOLVE requires 3 input arguments.");
    } else if (nlhs != 1) {
      	mexErrMsgTxt("LUSOLVE requires 1 output argument.");
    }   

    /* Read the Sparse Monitor Flag */
    X = mxCreateString("spumoni");
    mexerr = mexCallMATLAB(1, &Y, 1, &X, "sparsfun");
    SPUMONI = mxGetScalar(Y);
    mxDestroyArray(Y);
    mxDestroyArray(X);
#if 0 /* V4 */
    mxFreeMatrix(Y);
    mxFreeMatrix(X);
#endif

    m = mxGetM(A_in);
    n = mxGetN(A_in);
    numrhs = mxGetN(b_in);
    if ( babble ) printf("m=%d, n=%d, numrhs=%d\n", m, n, numrhs);
    vb = mxGetPr(b_in);
    x_out = mxCreateDoubleMatrix(m, numrhs, mxREAL);

    x = mxGetPr(x_out);
    val = mxGetPr(A_in);
    rowind_64 = mxGetIr(A_in);
    colptr_64 = mxGetJc(A_in);
    perm_c_64 = mxGetIr(Pc_in); 
    nnz = colptr_64[n];
    perm_r = (int *) mxCalloc(m, sizeof(int));
    perm_c = (int *) mxMalloc(n * sizeof(int));
    rowind = (int *) mxMalloc(nnz * sizeof(int));
    colptr = (int *) mxMalloc((n+1) * sizeof(int));
    for (i = 0; i < n; ++i) {
	perm_c[i] = perm_c_64[i];
	colptr[i] = colptr_64[i];
	/*printf("perm_c[%d] %d\n", i, perm_c[i]);*/
    }
    colptr[n] = colptr_64[n];
    for (i = 0; i < nnz; ++i) rowind[i] = rowind_64[i];

    dCreate_CompCol_Matrix(&A, m, n, nnz, val, rowind, colptr,
			   SLU_NC, SLU_D, SLU_GE);
    dCopy_Dense_Matrix(m, numrhs, vb, m, x, m);
    dCreate_Dense_Matrix(&B, m, numrhs, x, m, SLU_DN, SLU_D, SLU_GE);

    FlopsInSuperLU = 0;

    set_default_options(&options);
    options.ColPerm = MY_PERMC;
    StatInit(&stat);

    /* Call simple driver */
    if ( verbose )
      mexPrintf("Call LUSOLVE, use SUPERLU to factor first ...\n");
    dgssv(&options, &A, perm_c, perm_r, &L, &U, &B, &stat, &info);

#if 0 /* FLOPS is not available in the new Matlab. */
    /* Tell Matlab how many flops we did. */
    FlopsInSuperLU += LUFactFlops(&stat) + LUSolveFlops(&stat);
    if ( verbose ) mexPrintf("LUSOLVE flops: %.f\n", FlopsInSuperLU);
    mexerr = mexCallMATLAB(1, &X, 0, NULL, "flops");
    *(mxGetPr(X)) += FlopsInSuperLU;
    mexerr = mexCallMATLAB(1, &Y, 1, &X, "flops");
    mxDestroyArray(Y);
    mxDestroyArray(X);
#endif

    /* Construct Matlab solution matrix. */
    if ( !info ) {
        Destroy_SuperNode_Matrix(&L);
        Destroy_CompCol_Matrix(&U);
        if ( babble ) printf("Destroy L & U from SuperLU...\n");
    } else {
        printf("dgssv info = %d\n", info);
	mexErrMsgTxt("Error returned from C dgssv().");
    }

    mxFree(perm_r);
    mxFree(perm_c);
    mxFree(rowind);
    mxFree(colptr);
    StatFree(&stat);

    return;
 
}