#include <string.h>
#include "viz.h"


/*================= DOCUMENT RETURN VALUES! =================*/

int dfwrite_header ( file_info *headp)
{
    int	isize, flsize;
    cmndln_info *linep;
    FILE *fp;
    long Where_dataoff;
    long Where_lookoff;

    linep = &(headp->linefax);
    fp = headp->dspfoutfp;

    isize = sizeof (int);
    flsize = sizeof (float);
    /* print the header code on first line of file */
    if  (!fwrite  (DSPF_ID, strlen  (DSPF_ID), 1, fp))
	return (-1);
    /* the dimensions of the data */
    if (1 != fwrite (&headp->xdim, isize, 1, fp))
	return (-1);
    if (1 != fwrite (&headp->ydim, isize, 1, fp))
	return (-1);
    if (1 != fwrite (&headp->zdim, isize, 1, fp))
	return (-1);


    /* print out code for min and max values */
    if (1 != fwrite (&headp->min, flsize, 1, fp))
	return (-1);
    if (1 != fwrite (&headp->max, flsize, 1, fp))
	return (-1);

    /* the litmodel stored for each polygon */
    if (1 != fwrite (&linep->litmodel, isize, 1, fp))
	return (-1);

    /* write the total number of thresholds to be searched for*/
    if (1 != fwrite (&linep->nthres, isize, 1, fp))
	return (-1);
    /* write the array of thresholds out */
    if ((fwrite (linep->tvalue, flsize, linep->nthres, fp)) != linep->nthres)
    {
       fprintf (stderr, "ERROR: fwrite in dspf_header.c\n");
       return (-1);
    }

    /* write the offset to the lookup table*/
    /* the first time this number is set to 0*/ 
    /*this information will be overwritten after dspf is done*/
    /* ftell keeps track of where this information is to be placed*/
    Where_lookoff =  ftell (fp);      
    headp->Lookoff = 0;
    if (1 != fwrite (&headp->Lookoff, sizeof (long), 1, fp))
	return (-1);
    
    /* code to determine the length of the binary file header */
    /* Dataoff = length of the header */
    /*Dataoff = strlen (DSPF_ID) + 7*isize + 5*flsize + linep->nthres*flsize;*/
    Where_dataoff =  ftell (fp);      
    headp->Dataoff = 0;
    if (1 != fwrite (&headp->Dataoff, sizeof (long), 1, fp))
	return (-1);
   


    /* End of header,  now go back and fill in what we can */
    headp->Dataoff = ftell (fp);
    fseek (fp, Where_dataoff, 0); 
    if (1 != fwrite (&headp->Dataoff, sizeof (long), 1, fp))
	return (-1);

    fseek (fp, headp->Dataoff, 0);  /* and return to begin writing data */

    /* will still have to come back once more to fill in Lookup offset */

    return (0);
}


/**************************** dfread_header **********************************/
/**************************** dfread_header **********************************/
/**************************** dfread_header **********************************/

int 
dfread_header (file_info *headp)
{
    int	isize, flsize;
    FILE *fp;
    cmndln_info *linep;
    char buf[80];
    int len;
    
    fp = headp->dspfinfp;


    len = strlen (DSPF_ID);
    fseek (fp, 0L, 0);		/* rewind file */
    /*read in header information and store in File_info struct */

    if (!fread (buf, 1, len, fp)) return (-1);
    buf[len] = 0;
    if (strncmp (DSPF_ID, buf, len))
    {
        if (!strncmp ("dspf003.01", buf, len))
	    return (dfread_header_old (headp, fp));

	fprintf(stderr, "Error: header mismatch '%s' - '%s'\n", DSPF_ID, buf);
	return (-1);
    }
    linep = &(headp->linefax);
    isize = sizeof (int);
    flsize = sizeof (float);

    if (!fread (&headp->xdim,     isize, 1, fp)) return (-1);
    if (!fread (&headp->ydim,     isize, 1, fp)) return (-1);
    if (!fread (&headp->zdim,     isize, 1, fp)) return (-1);
    if (!fread (&headp->min,     flsize, 1, fp)) return (-1);
    if (!fread (&headp->max,     flsize, 1, fp)) return (-1);
    if (!fread (&linep->litmodel, isize, 1, fp)) return (-1);
    if (!fread (&linep->nthres,   isize, 1, fp)) return (-1);
    if (!fread ( linep->tvalue,  flsize, linep->nthres, fp)) return (-1);
    if (!fread (&headp->Lookoff,  isize, 1, fp)) return (-1);
    if (!fread (&headp->Dataoff,  isize, 1, fp)) return (-1);

    print_head_info (headp);
    
    return (1);
}
int 
dfread_header_old (file_info *headp, FILE *fp)
{
    int	isize, flsize;
    cmndln_info *linep;
    float tmp;
    
    linep = &(headp->linefax);
    isize = sizeof (int);
    flsize = sizeof (float);

    if (!fread (&headp->xdim,     isize, 1, fp)) return (-1);
    if (!fread (&headp->ydim,     isize, 1, fp)) return (-1);
    if (!fread (&headp->zdim,     isize, 1, fp)) return (-1);
    if (!fread (&tmp,             flsize, 1, fp)) return (-1);
    if (!fread (&tmp,             flsize, 1, fp)) return (-1);
    if (!fread (&tmp,             flsize, 1, fp)) return (-1);
    if (!fread (&headp->min,     flsize, 1, fp)) return (-1);
    if (!fread (&headp->max,     flsize, 1, fp)) return (-1);
    if (!fread (&linep->litmodel, isize, 1, fp)) return (-1);
    if (!fread (&linep->nthres,   isize, 1, fp)) return (-1);
    if (!fread ( linep->tvalue,  flsize, linep->nthres, fp)) return (-1);
    if (!fread (&headp->Lookoff,  isize, 1, fp)) return (-1);
    if (!fread (&headp->Dataoff,  isize, 1, fp)) return (-1);

    print_head_info (headp);
    
    return (1);
}