#include "slu_ddefs.h"

/*

 * -- SuperLU routine (version 4.1) --

 * Lawrence Berkeley National Laboratory

 * November, 2010

 */

int *GLOBAL_PERM_C, *GLOBAL_PERM_R;

SuperMatrix *GLOBAL_A, *GLOBAL_L, *GLOBAL_U;

SuperLUStat_t *GLOBAL_STAT;

void dmatvec_mult(double alpha, double x[], double beta, double y[])

{

    SuperMatrix *A = GLOBAL_A;

    sp_dgemv("N", alpha, A, x, 1, beta, y, 1);

}

void dpsolve(int n, double x[], double y[])

{

    extern void dcopy_(int *, double [], int *, double [], int *);

    int i_1 = 1;

    SuperMatrix *L = GLOBAL_L, *U = GLOBAL_U;

    SuperLUStat_t *stat = GLOBAL_STAT;

    int *perm_c = GLOBAL_PERM_C, *perm_r = GLOBAL_PERM_R;

    int info;

    static DNformat X;

    static SuperMatrix XX = {SLU_DN, SLU_D, SLU_GE, 1, 1, &X};

    dcopy_(&n, y, &i_1, x, &i_1);

    XX.nrow = n;

    X.lda = n;

    X.nzval = x;

    dgstrs(NOTRANS, L, U, perm_c, perm_r, &XX, stat, &info);

}

int main(int argc, char *argv[])

{

    void dmatvec_mult(double alpha, double x[], double beta, double y[]);

    void dpsolve(int n, double x[], double y[]);

    extern int dfgmr( int n,

	void (*matvec_mult)(double, double [], double, double []),

	void (*psolve)(int n, double [], double[]),

	double *rhs, double *sol, double tol, int restrt, int *itmax,

	FILE *fits);

    extern int dfill_diag(int n, NCformat *Astore);

    char     equed[1] = {'B'};

    yes_no_t equil;

    trans_t  trans;

    SuperMatrix A, L, U;

    SuperMatrix B, X;

    NCformat *Astore;

    NCformat *Ustore;

    SCformat *Lstore;

    double   *a;

    int      *asub, *xa;

    int      *etree;

    int      *perm_c; /* column permutation vector */

    int      *perm_r; /* row permutations from partial pivoting */

    int      nrhs, ldx, lwork, info, m, n, nnz;

    double   *rhsb, *rhsx, *xact;

    double   *work = NULL;

    double   *R, *C;

    double   u, rpg, rcond;

    double zero = 0.0;

    double one = 1.0;

    mem_usage_t   mem_usage;

    superlu_options_t options;

    SuperLUStat_t stat;

    int restrt, iter, maxit, i;

    double resid;

    double *x, *b;

#ifdef DEBUG

    extern int num_drop_L, num_drop_U;

#endif

#if ( DEBUGlevel>=1 )

    CHECK_MALLOC("Enter main()");

#endif

    /* Defaults */

    lwork = 0;

    nrhs  = 1;

    equil = YES;

    u	  = 0.1; /* u=1.0 for complete factorization */

    trans = NOTRANS;

    /* Set the default input options:

	options.Fact = DOFACT;

	options.Equil = YES;

	options.ColPerm = COLAMD;

	options.DiagPivotThresh = 0.1; //different from complete LU

	options.Trans = NOTRANS;

	options.IterRefine = NOREFINE;

	options.SymmetricMode = NO;

	options.PivotGrowth = NO;

	options.ConditionNumber = NO;

	options.PrintStat = YES;

	options.RowPerm = LargeDiag;

	options.ILU_DropTol = 1e-4;

	options.ILU_FillTol = 1e-2;

	options.ILU_FillFactor = 10.0;

	options.ILU_DropRule = DROP_BASIC | DROP_AREA;

	options.ILU_Norm = INF_NORM;

	options.ILU_MILU = SILU;

     */

    ilu_set_default_options(&options);

    /* Modify the defaults. */

    options.PivotGrowth = YES;	  /* Compute reciprocal pivot growth */

    options.ConditionNumber = YES;/* Compute reciprocal condition number */

    if ( lwork > 0 ) {

	work = SUPERLU_MALLOC(lwork);

	if ( !work ) ABORT("Malloc fails for work[].");

    }

    /* Read matrix A from a file in Harwell-Boeing format.*/

    if (argc < 2)

    {

	printf("Usage:\n%s [OPTION] < [INPUT] > [OUTPUT]\nOPTION:\n"

		"-h -hb:\n\t[INPUT] is a Harwell-Boeing format matrix.\n"

		"-r -rb:\n\t[INPUT] is a Rutherford-Boeing format matrix.\n"

		"-t -triplet:\n\t[INPUT] is a triplet format matrix.\n",

		argv[0]);

	return 0;

    }

    else

    {

	switch (argv[1][1])

	{

	    case 'H':

	    case 'h':

		printf("Input a Harwell-Boeing format matrix:\n");

		dreadhb(&m, &n, &nnz, &a, &asub, &xa);

		break;

	    case 'R':

	    case 'r':

		printf("Input a Rutherford-Boeing format matrix:\n");

		dreadrb(&m, &n, &nnz, &a, &asub, &xa);

		break;

	    case 'T':

	    case 't':

		printf("Input a triplet format matrix:\n");

		dreadtriple(&m, &n, &nnz, &a, &asub, &xa);

		break;

	    default:

		printf("Unrecognized format.\n");

		return 0;

	}

    }

    dCreate_CompCol_Matrix(&A, m, n, nnz, a, asub, xa, SLU_NC, SLU_D, SLU_GE);

    Astore = A.Store;

    dfill_diag(n, Astore);

    printf("Dimension %dx%d; # nonzeros %d\n", A.nrow, A.ncol, Astore->nnz);

    fflush(stdout);

    if ( !(rhsb = doubleMalloc(m * nrhs)) ) ABORT("Malloc fails for rhsb[].");

    if ( !(rhsx = doubleMalloc(m * nrhs)) ) ABORT("Malloc fails for rhsx[].");

    dCreate_Dense_Matrix(&B, m, nrhs, rhsb, m, SLU_DN, SLU_D, SLU_GE);

    dCreate_Dense_Matrix(&X, m, nrhs, rhsx, m, SLU_DN, SLU_D, SLU_GE);

    xact = doubleMalloc(n * nrhs);

    ldx = n;

    dGenXtrue(n, nrhs, xact, ldx);

    dFillRHS(trans, nrhs, xact, ldx, &A, &B);

    if ( !(etree = intMalloc(n)) ) ABORT("Malloc fails for etree[].");

    if ( !(perm_r = intMalloc(m)) ) ABORT("Malloc fails for perm_r[].");

    if ( !(perm_c = intMalloc(n)) ) ABORT("Malloc fails for perm_c[].");

    if ( !(R = (double *) SUPERLU_MALLOC(A.nrow * sizeof(double))) )

	ABORT("SUPERLU_MALLOC fails for R[].");

    if ( !(C = (double *) SUPERLU_MALLOC(A.ncol * sizeof(double))) )

	ABORT("SUPERLU_MALLOC fails for C[].");

    info = 0;

#ifdef DEBUG

    num_drop_L = 0;

    num_drop_U = 0;

#endif

    /* Initialize the statistics variables. */

    StatInit(&stat);

    /* Compute the incomplete factorization and compute the condition number

       and pivot growth using dgsisx. */

    dgsisx(&options, &A, perm_c, perm_r, etree, equed, R, C, &L, &U, work,

	   lwork, &B, &X, &rpg, &rcond, &mem_usage, &stat, &info);

    Lstore = (SCformat *) L.Store;

    Ustore = (NCformat *) U.Store;

    printf("dgsisx(): info %d\n", info);

    if (info > 0 || rcond < 1e-8 || rpg > 1e8)

	printf("WARNING: This preconditioner might be unstable.\n");

    if ( info == 0 || info == n+1 ) {

	if ( options.PivotGrowth == YES )

	    printf("Recip. pivot growth = %e\n", rpg);

	if ( options.ConditionNumber == YES )

	    printf("Recip. condition number = %e\n", rcond);

    } else if ( info > 0 && lwork == -1 ) {

	printf("** Estimated memory: %d bytes\n", info - n);

    }

    printf("n(A) = %d, nnz(A) = %d\n", n, Astore->nnz);

    printf("No of nonzeros in factor L = %d\n", Lstore->nnz);

    printf("No of nonzeros in factor U = %d\n", Ustore->nnz);

    printf("No of nonzeros in L+U = %d\n", Lstore->nnz + Ustore->nnz - n);

    printf("Fill ratio: nnz(F)/nnz(A) = %.3f\n",

	    ((double)(Lstore->nnz) + (double)(Ustore->nnz) - (double)n)

	    / (double)Astore->nnz);

    printf("L\\U MB %.3f\ttotal MB needed %.3f\n",

	   mem_usage.for_lu/1e6, mem_usage.total_needed/1e6);

    fflush(stdout);

    /* Set the global variables. */

    GLOBAL_A = &A;

    GLOBAL_L = &L;

    GLOBAL_U = &U;

    GLOBAL_STAT = &stat;

    GLOBAL_PERM_C = perm_c;

    GLOBAL_PERM_R = perm_r;

    /* Set the variables used by GMRES. */

    restrt = SUPERLU_MIN(n / 3 + 1, 50);

    maxit = 1000;

    iter = maxit;

    resid = 1e-8;

    if (!(b = doubleMalloc(m))) ABORT("Malloc fails for b[].");

    if (!(x = doubleMalloc(n))) ABORT("Malloc fails for x[].");

    if (info <= n + 1)

    {

	int i_1 = 1;

	double maxferr = 0.0, nrmA, nrmB, res, t;

        double temp;

	extern double dnrm2_(int *, double [], int *);

	extern void daxpy_(int *, double *, double [], int *, double [], int *);

	/* Call GMRES. */

	for (i = 0; i < n; i++) b[i] = rhsb[i];

	for (i = 0; i < n; i++) x[i] = zero;

	t = SuperLU_timer_();

	dfgmr(n, dmatvec_mult, dpsolve, b, x, resid, restrt, &iter, stdout);

	t = SuperLU_timer_() - t;

	/* Output the result. */

	nrmA = dnrm2_(&(Astore->nnz), (double *)((DNformat *)A.Store)->nzval,

		&i_1);

	nrmB = dnrm2_(&m, b, &i_1);

	sp_dgemv("N", -1.0, &A, x, 1, 1.0, b, 1);

	res = dnrm2_(&m, b, &i_1);

	resid = res / nrmB;

	printf("||A||_F = %.1e, ||B||_2 = %.1e, ||B-A*X||_2 = %.1e, "

		"relres = %.1e\n", nrmA, nrmB, res, resid);

	if (iter >= maxit)

	{

	    if (resid >= 1.0) iter = -180;

	    else if (resid > 1e-8) iter = -111;

	}

	printf("iteration: %d\nresidual: %.1e\nGMRES time: %.2f seconds.\n",

		iter, resid, t);

	/* Scale the solution back if equilibration was performed. */

	if (*equed == 'C' || *equed == 'B') 

	    for (i = 0; i < n; i++) x[i] *= C[i];

	for (i = 0; i < m; i++) {

	    maxferr = SUPERLU_MAX(maxferr, fabs(x[i] - xact[i]));

        }

	printf("||X-X_true||_oo = %.1e\n", maxferr);

    }

#ifdef DEBUG

    printf("%d entries in L and %d entries in U dropped.\n",

	    num_drop_L, num_drop_U);

#endif

    fflush(stdout);

    if ( options.PrintStat ) StatPrint(&stat);

    StatFree(&stat);

    SUPERLU_FREE (rhsb);

    SUPERLU_FREE (rhsx);

    SUPERLU_FREE (xact);

    SUPERLU_FREE (etree);

    SUPERLU_FREE (perm_r);

    SUPERLU_FREE (perm_c);

    SUPERLU_FREE (R);

    SUPERLU_FREE (C);

    Destroy_CompCol_Matrix(&A);

    Destroy_SuperMatrix_Store(&B);

    Destroy_SuperMatrix_Store(&X);

    if ( lwork >= 0 ) {

	Destroy_SuperNode_Matrix(&L);

	Destroy_CompCol_Matrix(&U);

    }

    SUPERLU_FREE(b);

    SUPERLU_FREE(x);

#if ( DEBUGlevel>=1 )

    CHECK_MALLOC("Exit main()");

#endif

    return 0;

}