/**
 *
 * @file mmio.c
 *
 * Matrix Market I/O library for ANSI C
 * See http://math.nist.gov/MatrixMarket for details.
 *
 **/
#include "common.h"
#include "spm_drivers.h"
#include "drivers/mmio.h"
#include <ctype.h>

static inline char *
mm_fgets( char *line, int bufsiz, FILE *infile ) {
    if (NULL == fgets(line, bufsiz, infile)) {
        line[0] = '\0';
        return NULL;
    }
    return line;
}

int mm_read_unsymmetric_sparse(const char *fname, int *M_, int *N_, int *nz_,
                               double **val_, int **row_, int **col_)
{
    FILE *f;
    MM_typecode matcode;
    int M, N, nz;
    int i;
    double *val;
    int *row, *col;

    if ((f = fopen(fname, "r")) == NULL) {
        return -1;
    }

    if (mm_read_banner(f, &matcode) != 0)
    {
        printf("mm_read_unsymetric: Could not process Matrix Market banner ");
        printf(" in file [%s]\n", fname);
        fclose(f);
        return -1;
    }

    if ( !(mm_is_real(matcode)   &&
           mm_is_matrix(matcode) &&
           mm_is_sparse(matcode)) )
    {
        char *code = mm_typecode_to_str(matcode);
        fprintf( stderr,
                 "Sorry, this application does not support Matrix Market type: [%s]\n", code );
        free(code);
        fclose(f);
        return -1;
    }

    /* find out size of sparse matrix: M, N, nz .... */

    if ( mm_read_mtx_crd_size(f, &M, &N, &nz) != 0 )
    {
        fprintf(stderr, "read_unsymmetric_sparse(): could not parse matrix size.\n");
        fclose(f);
        return -1;
    }
    if ( (M <= 0) || (N <= 0) || (nz <= 0) )
    {
        fprintf(stderr, "read_unsymmetric_sparse(): could not parse matrix size.\n");
        fclose(f);
        return -1;
    }
    *M_ = M;
    *N_ = N;
    *nz_ = nz;

    /* reseve memory for matrices */

    row = (int *) malloc(nz * sizeof(int));
    col = (int *) malloc(nz * sizeof(int));
    val = (double *) malloc(nz * sizeof(double));

    *val_ = val;
    *row_ = row;
    *col_ = col;

    /* NOTE: when reading in doubles, ANSI C requires the use of the "l"  */
    /*   specifier as in "%lg", "%lf", "%le", otherwise errors will occur */
    /*  (ANSI C X3.159-1989, Sec. 4.9.6.2, p. 136 lines 13-15)            */

    for (i=0; i<nz; i++)
    {
      if (3 != fscanf(f, "%d %d %lg\n", &row[i], &col[i], &val[i]))
        {
          fprintf(stderr, "Error: reading matrix\n");
          fclose(f);
          return 1;
        }
        row[i]--;  /* adjust from 1-based to 0-based */
        col[i]--;
    }
    fclose(f);

    return 0;
}

int mm_is_valid(MM_typecode matcode)
{
    if (!mm_is_matrix(matcode)) return 0;
    if (mm_is_dense(matcode) && mm_is_pattern(matcode)) return 0;
    if (mm_is_real(matcode) && mm_is_hermitian(matcode)) return 0;
    if (mm_is_pattern(matcode) && (mm_is_hermitian(matcode) ||
                mm_is_skew(matcode))) return 0;
    return 1;
}

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 (mm_fgets(line, MM_MAX_LINE_LENGTH, f) == NULL) {
        return MM_PREMATURE_EOF;
    }

    if ( sscanf(line, "%63s %63s %63s %63s %63s",
                banner, mtx, crd,
                data_type, storage_scheme) != 5 )
    {
        return MM_PREMATURE_EOF;
    }

    for (p=mtx; *p!='\0'; *p=(char)tolower((int)*p),p++);  /* convert to lower case */
    for (p=crd; *p!='\0'; *p=(char)tolower((int)*p),p++);
    for (p=data_type; *p!='\0'; *p=(char)tolower((int)*p),p++);
    for (p=storage_scheme; *p!='\0'; *p=(char)tolower((int)*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_write_mtx_crd_size(FILE *f, int M, int N, int nz)
{
    if (fprintf(f, "%d %d %d\n", M, N, nz) != 3)
        return MM_COULD_NOT_WRITE_FILE;
    else
        return 0;
}

int mm_read_mtx_crd_size(FILE *f, int *M, int *N, int *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 (mm_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, "%d %d %d", M, N, nz) == 3)
        return 0;

    else
    do
    {
        num_items_read = fscanf(f, "%d %d %d", M, N, nz);
        if (num_items_read == EOF) return MM_PREMATURE_EOF;
    }
    while (num_items_read != 3);

    return 0;
}


int mm_read_mtx_array_size(FILE *f, int *M, int *N)
{
    char line[MM_MAX_LINE_LENGTH];
    int num_items_read;
    /* set return null parameter values, in case we exit with errors */
    *M = *N = 0;

    /* now continue scanning until you reach the end-of-comments */
    do
    {
        if (mm_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, "%d %d", M, N) == 2)
        return 0;

    else /* we have a blank line */
    do
    {
        num_items_read = fscanf(f, "%d %d", M, N);
        if (num_items_read == EOF) return MM_PREMATURE_EOF;
    }
    while (num_items_read != 2);

    return 0;
}

int mm_write_mtx_array_size(FILE *f, int M, int N)
{
    if (fprintf(f, "%d %d\n", M, N) != 2)
        return MM_COULD_NOT_WRITE_FILE;
    else
        return 0;
}



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

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

int mm_read_mtx_crd_data(FILE *f, int M, int N, int nz, int row[], int col[],
                         double val[], MM_typecode matcode)
{
    int i;
    (void)M; (void)N;

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

        }
    }

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

    return 0;

}

int mm_read_mtx_crd_entry(FILE *f, int *row, int *col,
        double *real, double *imag, MM_typecode matcode)
{
    if (mm_is_complex(matcode))
    {
            if (fscanf(f, "%d %d %lg %lg", row, col, real, imag)
                != 4) return MM_PREMATURE_EOF;
    }
    else if (mm_is_real(matcode))
    {
            if (fscanf(f, "%d %d %lg\n", row, col, real)
                != 3) return MM_PREMATURE_EOF;

    }

    else if (mm_is_pattern(matcode))
    {
            if (fscanf(f, "%d %d", row, col) != 2) return MM_PREMATURE_EOF;
    }
    else
        return MM_UNSUPPORTED_TYPE;

    return 0;

}


/************************************************************************
    mm_read_mtx_crd()  fills M, N, nz, array of values, and return
                        type code, e.g. 'MCRS'

                        if matrix is complex, values[] is of size 2*nz,
                            (nz pairs of real/imaginary values)
************************************************************************/

int mm_read_mtx_crd(char *fname, int *M, int *N, int *nz, int **row, int **col,
        double **val, MM_typecode *matcode)
{
    int ret_code;
    FILE *f;

    if (strcmp(fname, "stdin") == 0) f=stdin;
    else
    if ((f = fopen(fname, "r")) == NULL)
        return MM_COULD_NOT_READ_FILE;

    if ((ret_code = mm_read_banner(f, matcode)) != 0) {
        if (f != stdin) fclose(f);
        return ret_code;
    }
    if (!(mm_is_valid(*matcode)  &&
          mm_is_sparse(*matcode) &&
          mm_is_matrix(*matcode)) )
    {
        if (f != stdin) fclose(f);
        return MM_UNSUPPORTED_TYPE;
    }
    if ((ret_code = mm_read_mtx_crd_size(f, M, N, nz)) != 0) {
        if (f != stdin) fclose(f);
        return ret_code;
    }

    *row = (int *)  malloc(*nz * sizeof(int));
    *col = (int *)  malloc(*nz * sizeof(int));
    *val = NULL;

    if (mm_is_complex(*matcode))
    {
        *val = (double *) malloc(*nz * 2 * sizeof(double));
        ret_code = mm_read_mtx_crd_data(f, *M, *N, *nz, *row, *col, *val,
                *matcode);
        if (ret_code != 0) {
            if (f != stdin) fclose(f);
            return ret_code;
        }
    }
    else if (mm_is_real(*matcode))
    {
        *val = (double *) malloc(*nz * sizeof(double));
        ret_code = mm_read_mtx_crd_data(f, *M, *N, *nz, *row, *col, *val,
                *matcode);
        if (ret_code != 0) {
            if (f != stdin) fclose(f);
            return ret_code;
        }
    }

    else if (mm_is_pattern(*matcode))
    {
        ret_code = mm_read_mtx_crd_data(f, *M, *N, *nz, *row, *col, *val,
                *matcode);
        if (ret_code != 0) {
            if (f != stdin) fclose(f);
            return ret_code;
        }
    }

    if (f != stdin) fclose(f);
    return 0;
}

int mm_write_banner(FILE *f, MM_typecode matcode)
{
    char *str = mm_typecode_to_str(matcode);
    int ret_code;

    ret_code = fprintf(f, "%s %s\n", MatrixMarketBanner, str);
    free(str);
    if (ret_code !=2 )
        return MM_COULD_NOT_WRITE_FILE;
    else
        return 0;
}

int mm_write_mtx_crd(char fname[], int M, int N, int nz, int row[], int col[],
                     double val[], MM_typecode matcode)
{
    FILE *f;
    char *strcode;
    int i;

    if (strcmp(fname, "stdout") == 0) {
        f = stdout;
    }
    else {
        if ((f = fopen(fname, "w")) == NULL) {
            return MM_COULD_NOT_WRITE_FILE;
        }
    }

    /* print banner followed by typecode */
    strcode = mm_typecode_to_str(matcode);
    fprintf( f, "%s ", MatrixMarketBanner );
    fprintf( f, "%s\n", strcode );
    free( strcode );

    /* print matrix sizes and nonzeros */
    fprintf(f, "%d %d %d\n", M, N, nz);

    /* print values */
    if (mm_is_pattern(matcode)) {
        for (i=0; i<nz; i++) {
            fprintf(f, "%d %d\n", row[i], col[i]);
        }
    }
    else {
        if (mm_is_real(matcode)) {
            for (i=0; i<nz; i++) {
                fprintf(f, "%d %d %20.16g\n", row[i], col[i], val[i]);
            }
        }
        else {
            if (mm_is_complex(matcode)) {
                for (i=0; i<nz; i++) {
                    fprintf(f, "%d %d %20.16g %20.16g\n", row[i], col[i], val[2*i],
                            val[2*i+1]);
                }
            }
            else
            {
                if (f != stdout) {
                    fclose(f);
                }
                return MM_UNSUPPORTED_TYPE;
            }
        }
    }

    if (f !=stdout) {
        fclose(f);
    }

    return 0;
}


/**
*  Create a new copy of a string s.  mm_strdup() is a common routine, but
*  not part of ANSI C, so it is included here.  Used by mm_typecode_to_str().
*
*/
char *mm_strdup(const char *s)
{
        int len = strlen(s);
        char *s2 = (char *) malloc((len+1)*sizeof(char));
        return strcpy(s2, s);
}

char  *mm_typecode_to_str(MM_typecode matcode)
{
    char buffer[MM_MAX_LINE_LENGTH];
    char *types[4];
    char *mm_strdup(const char *);

    /* check for MTX type */
    if (mm_is_matrix(matcode))
        types[0] = MM_MTX_STR;
    else
        return NULL;

    /* check for CRD or ARR matrix */
    if (mm_is_sparse(matcode))
        types[1] = MM_SPARSE_STR;
    else
    if (mm_is_dense(matcode))
        types[1] = MM_DENSE_STR;
    else
        return NULL;

    /* check for element data type */
    if (mm_is_real(matcode))
        types[2] = MM_REAL_STR;
    else
    if (mm_is_complex(matcode))
        types[2] = MM_COMPLEX_STR;
    else
    if (mm_is_pattern(matcode))
        types[2] = MM_PATTERN_STR;
    else
    if (mm_is_integer(matcode))
        types[2] = MM_INT_STR;
    else
        return NULL;


    /* check for symmetry type */
    if (mm_is_general(matcode))
        types[3] = MM_GENERAL_STR;
    else
    if (mm_is_symmetric(matcode))
        types[3] = MM_SYMM_STR;
    else
    if (mm_is_hermitian(matcode))
        types[3] = MM_HERM_STR;
    else
    if (mm_is_skew(matcode))
        types[3] = MM_SKEW_STR;
    else
        return NULL;

    sprintf(buffer,"%s %s %s %s", types[0], types[1], types[2], types[3]);
    return mm_strdup(buffer);

}
