/*! \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.
*/

/*! @file dreadhb.c
 * \brief Read a matrix stored in Harwell-Boeing format
 *
 * <pre>
 * -- SuperLU routine (version 2.0) --
 * Univ. of California Berkeley, Xerox Palo Alto Research Center,
 * and Lawrence Berkeley National Lab.
 * November 15, 1997
 *
 * Purpose
 * =======
 * 
 * Read a DOUBLE PRECISION matrix stored in Harwell-Boeing format 
 * as described below.
 * 
 * Line 1 (A72,A8) 
 *  	Col. 1 - 72   Title (TITLE) 
 *	Col. 73 - 80  Key (KEY) 
 * 
 * Line 2 (5I14) 
 * 	Col. 1 - 14   Total number of lines excluding header (TOTCRD) 
 * 	Col. 15 - 28  Number of lines for pointers (PTRCRD) 
 * 	Col. 29 - 42  Number of lines for row (or variable) indices (INDCRD) 
 * 	Col. 43 - 56  Number of lines for numerical values (VALCRD) 
 *	Col. 57 - 70  Number of lines for right-hand sides (RHSCRD) 
 *                    (including starting guesses and solution vectors 
 *		       if present) 
 *           	      (zero indicates no right-hand side data is present) 
 *
 * Line 3 (A3, 11X, 4I14) 
 *   	Col. 1 - 3    Matrix type (see below) (MXTYPE) 
 * 	Col. 15 - 28  Number of rows (or variables) (NROW) 
 * 	Col. 29 - 42  Number of columns (or elements) (NCOL) 
 *	Col. 43 - 56  Number of row (or variable) indices (NNZERO) 
 *	              (equal to number of entries for assembled matrices) 
 * 	Col. 57 - 70  Number of elemental matrix entries (NELTVL) 
 *	              (zero in the case of assembled matrices) 
 * Line 4 (2A16, 2A20) 
 * 	Col. 1 - 16   Format for pointers (PTRFMT) 
 *	Col. 17 - 32  Format for row (or variable) indices (INDFMT) 
 *	Col. 33 - 52  Format for numerical values of coefficient matrix (VALFMT) 
 * 	Col. 53 - 72 Format for numerical values of right-hand sides (RHSFMT) 
 *
 * Line 5 (A3, 11X, 2I14) Only present if there are right-hand sides present 
 *    	Col. 1 	      Right-hand side type: 
 *	         	  F for full storage or M for same format as matrix 
 *    	Col. 2        G if a starting vector(s) (Guess) is supplied. (RHSTYP) 
 *    	Col. 3        X if an exact solution vector(s) is supplied. 
 *	Col. 15 - 28  Number of right-hand sides (NRHS) 
 *	Col. 29 - 42  Number of row indices (NRHSIX) 
 *          	      (ignored in case of unassembled matrices) 
 *
 * The three character type field on line 3 describes the matrix type. 
 * The following table lists the permitted values for each of the three 
 * characters. As an example of the type field, RSA denotes that the matrix 
 * is real, symmetric, and assembled. 
 *
 * First Character: 
 *	R Real matrix 
 *	C Complex matrix 
 *	P Pattern only (no numerical values supplied) 
 *
 * Second Character: 
 *	S Symmetric 
 *	U Unsymmetric 
 *	H Hermitian 
 *	Z Skew symmetric 
 *	R Rectangular 
 *
 * Third Character: 
 *	A Assembled 
 *	E Elemental matrices (unassembled) 
 *
 * </pre>
 */
#include <stdio.h>
#include <stdlib.h>
#include "slu_ddefs.h"


/*! \brief Eat up the rest of the current line */
int dDumpLine(FILE *fp)
{
    register int c;
    while ((c = fgetc(fp)) != '\n') ;
    return 0;
}

int dParseIntFormat(char *buf, int *num, int *size)
{
    char *tmp;

    tmp = buf;
    while (*tmp++ != '(') ;
    sscanf(tmp, "%d", num);
    while (*tmp != 'I' && *tmp != 'i') ++tmp;
    ++tmp;
    sscanf(tmp, "%d", size);
    return 0;
}

int dParseFloatFormat(char *buf, int *num, int *size)
{
    char *tmp, *period;
    
    tmp = buf;
    while (*tmp++ != '(') ;
    *num = atoi(tmp); /*sscanf(tmp, "%d", num);*/
    while (*tmp != 'E' && *tmp != 'e' && *tmp != 'D' && *tmp != 'd'
	   && *tmp != 'F' && *tmp != 'f') {
        /* May find kP before nE/nD/nF, like (1P6F13.6). In this case the
           num picked up refers to P, which should be skipped. */
        if (*tmp=='p' || *tmp=='P') {
           ++tmp;
           *num = atoi(tmp); /*sscanf(tmp, "%d", num);*/
        } else {
           ++tmp;
        }
    }
    ++tmp;
    period = tmp;
    while (*period != '.' && *period != ')') ++period ;
    *period = '\0';
    *size = atoi(tmp); /*sscanf(tmp, "%2d", size);*/

    return 0;
}

static int ReadVector(FILE *fp, int n, int *where, int perline, int persize)
{
    register int i, j, item;
    char tmp, buf[100];
    
    i = 0;
    while (i <  n) {
	fgets(buf, 100, fp);    /* read a line at a time */
	for (j=0; j<perline && i<n; j++) {
	    tmp = buf[(j+1)*persize];     /* save the char at that place */
	    buf[(j+1)*persize] = 0;       /* null terminate */
	    item = atoi(&buf[j*persize]); 
	    buf[(j+1)*persize] = tmp;     /* recover the char at that place */
	    where[i++] = item - 1;
	}
    }

    return 0;
}

int dReadValues(FILE *fp, int n, double *destination, int perline, int persize)
{
    register int i, j, k, s;
    char tmp, buf[100];
    
    i = 0;
    while (i < n) {
	fgets(buf, 100, fp);    /* read a line at a time */
	for (j=0; j<perline && i<n; j++) {
	    tmp = buf[(j+1)*persize];     /* save the char at that place */
	    buf[(j+1)*persize] = 0;       /* null terminate */
	    s = j*persize;
	    for (k = 0; k < persize; ++k) /* No D_ format in C */
		if ( buf[s+k] == 'D' || buf[s+k] == 'd' ) buf[s+k] = 'E';
	    destination[i++] = atof(&buf[s]);
	    buf[(j+1)*persize] = tmp;     /* recover the char at that place */
	}
    }

    return 0;
}


/*! \brief
 *
 * <pre>
 * On input, nonz/nzval/rowind/colptr represents lower part of a symmetric
 * matrix. On exit, it represents the full matrix with lower and upper parts.
 * </pre>
 */
static void
FormFullA(int n, int *nonz, double **nzval, int **rowind, int **colptr)
{
    register int i, j, k, col, new_nnz;
    int *t_rowind, *t_colptr, *al_rowind, *al_colptr, *a_rowind, *a_colptr;
    int *marker;
    double *t_val, *al_val, *a_val;

    al_rowind = *rowind;
    al_colptr = *colptr;
    al_val = *nzval;

    if ( !(marker =(int *) SUPERLU_MALLOC( (n+1) * sizeof(int)) ) )
	ABORT("SUPERLU_MALLOC fails for marker[]");
    if ( !(t_colptr = (int *) SUPERLU_MALLOC( (n+1) * sizeof(int)) ) )
	ABORT("SUPERLU_MALLOC t_colptr[]");
    if ( !(t_rowind = (int *) SUPERLU_MALLOC( *nonz * sizeof(int)) ) )
	ABORT("SUPERLU_MALLOC fails for t_rowind[]");
    if ( !(t_val = (double*) SUPERLU_MALLOC( *nonz * sizeof(double)) ) )
	ABORT("SUPERLU_MALLOC fails for t_val[]");

    /* Get counts of each column of T, and set up column pointers */
    for (i = 0; i < n; ++i) marker[i] = 0;
    for (j = 0; j < n; ++j) {
	for (i = al_colptr[j]; i < al_colptr[j+1]; ++i)
	    ++marker[al_rowind[i]];
    }
    t_colptr[0] = 0;
    for (i = 0; i < n; ++i) {
	t_colptr[i+1] = t_colptr[i] + marker[i];
	marker[i] = t_colptr[i];
    }

    /* Transpose matrix A to T */
    for (j = 0; j < n; ++j)
	for (i = al_colptr[j]; i < al_colptr[j+1]; ++i) {
	    col = al_rowind[i];
	    t_rowind[marker[col]] = j;
	    t_val[marker[col]] = al_val[i];
	    ++marker[col];
	}

    new_nnz = *nonz * 2 - n;
    if ( !(a_colptr = (int *) SUPERLU_MALLOC( (n+1) * sizeof(int)) ) )
	ABORT("SUPERLU_MALLOC a_colptr[]");
    if ( !(a_rowind = (int *) SUPERLU_MALLOC( new_nnz * sizeof(int)) ) )
	ABORT("SUPERLU_MALLOC fails for a_rowind[]");
    if ( !(a_val = (double*) SUPERLU_MALLOC( new_nnz * sizeof(double)) ) )
	ABORT("SUPERLU_MALLOC fails for a_val[]");
    
    a_colptr[0] = 0;
    k = 0;
    for (j = 0; j < n; ++j) {
      for (i = t_colptr[j]; i < t_colptr[j+1]; ++i) {
	if ( t_rowind[i] != j ) { /* not diagonal */
	  a_rowind[k] = t_rowind[i];
	  a_val[k] = t_val[i];
#ifdef DEBUG
	  if ( fabs(a_val[k]) < 4.047e-300 )
	      printf("%5d: %e\n", k, a_val[k]);
#endif
	  ++k;
	}
      }

      for (i = al_colptr[j]; i < al_colptr[j+1]; ++i) {
	a_rowind[k] = al_rowind[i];
	a_val[k] = al_val[i];
#ifdef DEBUG
	if ( fabs(a_val[k]) < 4.047e-300 )
	    printf("%5d: %e\n", k, a_val[k]);
#endif
	++k;
      }
      
      a_colptr[j+1] = k;
    }

    printf("FormFullA: new_nnz = %d, k = %d\n", new_nnz, k);

    SUPERLU_FREE(al_val);
    SUPERLU_FREE(al_rowind);
    SUPERLU_FREE(al_colptr);
    SUPERLU_FREE(marker);
    SUPERLU_FREE(t_val);
    SUPERLU_FREE(t_rowind);
    SUPERLU_FREE(t_colptr);

    *nzval = a_val;
    *rowind = a_rowind;
    *colptr = a_colptr;
    *nonz = new_nnz;
}

void
dreadhb(FILE *fp, int *nrow, int *ncol, int *nonz,
	double **nzval, int **rowind, int **colptr)
{

    register int i, numer_lines = 0, rhscrd = 0;
    int tmp, colnum, colsize, rownum, rowsize, valnum, valsize;
    char buf[100], type[4], key[10];
    int sym;

    /* Line 1 */
    fgets(buf, 100, fp);
    fputs(buf, stdout);
#if 0
    fscanf(fp, "%72c", buf); buf[72] = 0;
    printf("Title: %s", buf);
    fscanf(fp, "%8c", key);  key[8] = 0;
    printf("Key: %s\n", key);
    dDumpLine(fp);
#endif

    /* Line 2 */
    for (i=0; i<5; i++) {
	fscanf(fp, "%14c", buf); buf[14] = 0;
	sscanf(buf, "%d", &tmp);
	if (i == 3) numer_lines = tmp;
	if (i == 4 && tmp) rhscrd = tmp;
    }
    dDumpLine(fp);

    /* Line 3 */
    fscanf(fp, "%3c", type);
    fscanf(fp, "%11c", buf); /* pad */
    type[3] = 0;
#ifdef DEBUG
    printf("Matrix type %s\n", type);
#endif
    
    fscanf(fp, "%14c", buf); sscanf(buf, "%d", nrow);
    fscanf(fp, "%14c", buf); sscanf(buf, "%d", ncol);
    fscanf(fp, "%14c", buf); sscanf(buf, "%d", nonz);
    fscanf(fp, "%14c", buf); sscanf(buf, "%d", &tmp);
    
    if (tmp != 0)
	  printf("This is not an assembled matrix!\n");
    if (*nrow != *ncol)
	printf("Matrix is not square.\n");
    dDumpLine(fp);

    /* Allocate storage for the three arrays ( nzval, rowind, colptr ) */
    dallocateA(*ncol, *nonz, nzval, rowind, colptr);

    /* Line 4: format statement */
    fscanf(fp, "%16c", buf);
    dParseIntFormat(buf, &colnum, &colsize);
    fscanf(fp, "%16c", buf);
    dParseIntFormat(buf, &rownum, &rowsize);
    fscanf(fp, "%20c", buf);
    dParseFloatFormat(buf, &valnum, &valsize);
    fscanf(fp, "%20c", buf);
    dDumpLine(fp);

    /* Line 5: right-hand side */    
    if ( rhscrd ) dDumpLine(fp); /* skip RHSFMT */
    
#ifdef DEBUG
    printf("%d rows, %d nonzeros\n", *nrow, *nonz);
    printf("colnum %d, colsize %d\n", colnum, colsize);
    printf("rownum %d, rowsize %d\n", rownum, rowsize);
    printf("valnum %d, valsize %d\n", valnum, valsize);
#endif
    
    ReadVector(fp, *ncol+1, *colptr, colnum, colsize);
    ReadVector(fp, *nonz, *rowind, rownum, rowsize);
    if ( numer_lines ) {
        dReadValues(fp, *nonz, *nzval, valnum, valsize);
    }
    
    sym = (type[1] == 'S' || type[1] == 's');
    if ( sym ) {
	FormFullA(*ncol, nonz, nzval, rowind, colptr);
    }

    fclose(fp);
}