/* 
*   Matrix Market I/O library for ANSI C
*
*   See http://math.nist.gov/MatrixMarket for details.
*
*
*/


#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <inttypes.h>
#define ID PRId64

#include "mmio.h"

int mm_read_banner(FILE *f, MM_typecode *matcode)
{
    char line[MM_MAX_LINE_LENGTH];
    char banner[MM_MAX_TOKEN_LENGTH];
    char mtx[MM_MAX_TOKEN_LENGTH]; 
    char crd[MM_MAX_TOKEN_LENGTH];
    char data_type[MM_MAX_TOKEN_LENGTH];
    char storage_scheme[MM_MAX_TOKEN_LENGTH];
    char *p;


    mm_clear_typecode(matcode);  

    if (fgets(line, MM_MAX_LINE_LENGTH, f) == NULL) 
        return MM_PREMATURE_EOF;

    if (sscanf(line, "%20s %20s %20s %20s %20s", banner, mtx, crd, data_type,
        storage_scheme) != 5)
        return MM_PREMATURE_EOF;

    for (p=mtx; *p!='\0'; *p=tolower(*p),p++);  /* convert to lower case */
    for (p=crd; *p!='\0'; *p=tolower(*p),p++);  
    for (p=data_type; *p!='\0'; *p=tolower(*p),p++);
    for (p=storage_scheme; *p!='\0'; *p=tolower(*p),p++);

    /* check for banner */
    if (strncmp(banner, MatrixMarketBanner, strlen(MatrixMarketBanner)) != 0)
        return MM_NO_HEADER;

    /* first field should be "mtx" */
    if (strcmp(mtx, MM_MTX_STR) != 0)
        return  MM_UNSUPPORTED_TYPE;
    mm_set_matrix(matcode);


    /* second field describes whether this is a sparse matrix (in coordinate
            storgae) or a dense array */


    if (strcmp(crd, MM_SPARSE_STR) == 0)
        mm_set_sparse(matcode);
    else
    if (strcmp(crd, MM_DENSE_STR) == 0)
            mm_set_dense(matcode);
    else
        return MM_UNSUPPORTED_TYPE;
    

    /* third field */

    if (strcmp(data_type, MM_REAL_STR) == 0)
        mm_set_real(matcode);
    else
    if (strcmp(data_type, MM_COMPLEX_STR) == 0)
        mm_set_complex(matcode);
    else
    if (strcmp(data_type, MM_PATTERN_STR) == 0)
        mm_set_pattern(matcode);
    else
    if (strcmp(data_type, MM_INT_STR) == 0)
        mm_set_integer(matcode);
    else
        return MM_UNSUPPORTED_TYPE;
    

    /* fourth field */

    if (strcmp(storage_scheme, MM_GENERAL_STR) == 0)
        mm_set_general(matcode);
    else
    if (strcmp(storage_scheme, MM_SYMM_STR) == 0)
        mm_set_symmetric(matcode);
    else
    if (strcmp(storage_scheme, MM_HERM_STR) == 0)
        mm_set_hermitian(matcode);
    else
    if (strcmp(storage_scheme, MM_SKEW_STR) == 0)
        mm_set_skew(matcode);
    else
        return MM_UNSUPPORTED_TYPE;
        

    return 0;
}

int mm_read_mtx_crd_size(FILE *f, int64_t *M, int64_t *N, int64_t *nz )
{
    char line[MM_MAX_LINE_LENGTH];
    int num_items_read;

    /* set return null parameter values, in case we exit with errors */
    *M = *N = *nz = 0;

    /* now continue scanning until you reach the end-of-comments */
    do 
    {
        if (fgets(line,MM_MAX_LINE_LENGTH,f) == NULL) 
            return MM_PREMATURE_EOF;
    } while (line[0] == '%');

    /* line[] is either blank or has M,N, nz */
    if (sscanf(line, "%"ID" %"ID" %"ID"", M, N, nz) == 3)
        return 0;
        
    else
    do
    { 
        num_items_read = fscanf(f, "%"ID" %"ID" %"ID"", M, N, nz); 
        if (num_items_read == EOF) return MM_PREMATURE_EOF;
    }
    while (num_items_read != 3);

    return 0;
}

/*-------------------------------------------------------------------------*/

/******************************************************************/
/* use when I[], J[], and val[]J, and val[] are already allocated */
/******************************************************************/

int mm_read_mtx_crd_data(FILE *f, int64_t M, int64_t N, int64_t nz, int64_t I[], int64_t J[],
        double val[], MM_typecode matcode)
{
    (void)M; // Unused variable
    (void)N; // Unused variable

    int64_t i;
    if (mm_is_complex(matcode))
    {
        for (i=0; i<nz; i++)
            if (fscanf(f, "%"ID" %"ID" %lg %lg", &I[i], &J[i], &val[2*i], &val[2*i+1])
                != 4) return MM_PREMATURE_EOF;
    }
    else if (mm_is_real(matcode) || mm_is_integer(matcode))
    {
        for (i=0; i<nz; i++)
        {
            if (fscanf(f, "%"ID" %"ID" %lg\n", &I[i], &J[i], &val[i])
                != 3) return MM_PREMATURE_EOF;

        }
    }
    else if (mm_is_pattern(matcode))
    {
        for (i=0; i<nz; i++)
            if (fscanf(f, "%"ID" %"ID"", &I[i], &J[i])
                != 2) return MM_PREMATURE_EOF;
    }
    else
        return MM_UNSUPPORTED_TYPE;

    return 0;
        
}