/* 
*   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 "mmio.h"

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;
    /*    int ret_code; */


    mm_clear_typecode(matcode);  

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

    if (sscanf(line, "%s %s %s %s %s", 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_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 ret_code;*/
    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, "%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 ret_code; */
    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 (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) == 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 I[], J[], and val[]J, and val[] are already allocated */
/******************************************************************/

int mm_read_mtx_crd_data(FILE *f, int M, int N, int nz, int I[], int J[],
        double val[], MM_typecode matcode)
{
    int i;
    if (mm_is_complex(matcode))
    {
        for (i=0; i<nz; i++)
            if (fscanf(f, "%d %d %lg %lg", &I[i], &J[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", &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, "%d %d", &I[i], &J[i])
                != 2) return MM_PREMATURE_EOF;
    }
    else
        return MM_UNSUPPORTED_TYPE;

    return 0;
        
}

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

    }

    else if (mm_is_pattern(matcode))
    {
            if (fscanf(f, "%d %d", I, J) != 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 **I, int **J, 
        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)
        return ret_code;

    if (!(mm_is_valid(*matcode) && mm_is_sparse(*matcode) && 
            mm_is_matrix(*matcode)))
        return MM_UNSUPPORTED_TYPE;

    if ((ret_code = mm_read_mtx_crd_size(f, M, N, nz)) != 0)
        return ret_code;


    *I = (int *)  malloc(*nz * sizeof(int));
    *J = (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, *I, *J, *val, 
                *matcode);
        if (ret_code != 0) 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, *I, *J, *val, 
                *matcode);
        if (ret_code != 0) return ret_code;
    }

    else if (mm_is_pattern(*matcode))
    {
        ret_code = mm_read_mtx_crd_data(f, *M, *N, *nz, *I, *J, *val, 
                *matcode);
        if (ret_code != 0) 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 I[], int J[],
        double val[], MM_typecode matcode)
{
    FILE *f;
    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 */
    fprintf(f, "%s ", MatrixMarketBanner);
    fprintf(f, "%s\n", mm_typecode_to_str(matcode));

    /* 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", I[i], J[i]);
    else
    if (mm_is_real(matcode))
        for (i=0; i<nz; i++)
            fprintf(f, "%d %d %20.16g\n", I[i], J[i], val[i]);
    else
    if (mm_is_complex(matcode))
        for (i=0; i<nz; i++)
            fprintf(f, "%d %d %20.16g %20.16g\n", I[i], J[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;
}
    

char  *mm_typecode_to_str(MM_typecode matcode)
{
    char buffer[MM_MAX_LINE_LENGTH];
    char *types[4];
    /*    int error =0; */
    /*   int i; */
    
    /* check for MTX type */
    if (mm_is_matrix(matcode)) 
        types[0] = MM_MTX_STR;
    /*
    else
        error=1;
    */
    /* 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 strdup(buffer);

}