#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "fitsio.h"

#define LINEPIX 2100
#define LINEPIY 1800

void printerror( int status );

int main(int argc, char *argv[])
{
  fitsfile *fp;
  int i,j,status,nfound,anynull,bitpix=-32;
  long fpixel, nelements,naxis=2;
  long naxes[2]={LINEPIX, LINEPIY},nbuffer;
  float nullval;
  static float buffer[LINEPIX],z[LINEPIY][LINEPIX];

  double extinc, wl[LINEPIX],dmag;
  int numstar;


  if(argc!=5){
    fprintf(stderr,"Usage : %s WL_map NUM Av output_file\n",argv[0]);
    exit(0);
  }

  sscanf(argv[2],"%d",  &numstar);
  sscanf(argv[3],"%lf",  &extinc);
  numstar--;

  fprintf(stderr,"Read %s  ... ",argv[1]);
  status=0;
  if(fits_open_file(&fp,argv[1], READONLY, &status))
    printerror(status);
  if(fits_read_keys_lng(fp, "NAXIS", 1, 2, naxes, &nfound, &status))
    printerror(status);
  fprintf(stderr,"%ld x %ld format ",naxes[0],naxes[1]);
  if((naxes[0]>LINEPIX)||(naxes[1]>LINEPIY/9)){
    fprintf(stderr,"\nIllegal image format\n");
    exit(0);
  }
  fpixel = 1;
  nullval = 0;
  nbuffer = naxes[0];
  for(i=0;i<naxes[1];i++){
    if (fits_read_img(fp, TFLOAT, fpixel, nbuffer, &nullval,
                      buffer, &anynull, &status))
      printerror(status);
    if(i==numstar){
      for(j=0;j<naxes[0];j++) wl[j]=buffer[j];
    }
    fpixel+=naxes[0];
  }
  if(fits_close_file(fp, &status))
    printerror(status);
  fprintf(stderr,"OK\n");

  naxes[1]*=9;
  for(i=0;i<naxes[1];i++) {
    for(j=0;j<naxes[0];j++) {
      if(i >= numstar*9 && i < (numstar+1)*9) {
	dmag = extinc * 0.4 * pow(wl[j],-1.6);
	//	fprintf(stderr,"%lf %lf\n", dmag,wl[j]);
	dmag = pow(10., -0.4*dmag);
	z[i][j] = dmag;
      } else {
	z[i][j] = 1.;
      }
    }
  }

  fprintf(stderr,"Write %s  ... ",argv[4]);
  status=0;
  if (fits_create_file(&fp, argv[4], &status))
    printerror(status);
  if (fits_create_img(fp, bitpix, naxis, naxes, &status))
    printerror(status);
  fprintf(stderr,"%ld x %ld format ",naxes[0],naxes[1]);
  fpixel=1;
  nelements=naxes[0];
  for(i=0;i<naxes[1];i++){
    if (fits_write_img(fp, TFLOAT, fpixel, nelements, z[i], &status))
      printerror(status);
    fpixel+=naxes[0];
  }
  if (fits_close_file(fp, &status))
    printerror(status);
  fprintf(stderr,"OK\n");
  return(0);
}

void printerror( int status)
{
    /*****************************************************/
    /* Print out cfitsio error messages and exit program */
    /*****************************************************/

    char status_str[FLEN_STATUS], errmsg[FLEN_ERRMSG];

    if (status)
      fprintf(stderr, "\n*** Error occurred during program execution ***\n");

    fits_get_errstatus(status, status_str);   /* get the error description */
    fprintf(stderr, "\nstatus = %d: %s\n", status, status_str);

    /* get first message; null if stack is empty */
    if ( fits_read_errmsg(errmsg) )    {
         fprintf(stderr, "\nError message stack:\n");
         fprintf(stderr, " %s\n", errmsg);

         while ( fits_read_errmsg(errmsg) )  /* get remaining messages */
             fprintf(stderr, " %s\n", errmsg);
    }

    exit( status );       /* terminate the program, returning error status */
}