#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,k,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];
  float w[9]={0.5,1,1,1,1,1,1,1,0.5};
  FILE *fpd;
  int keys=1;
  char ctype1[16],cunit1[16],ctype2[16],cunit2[16];
  float crpix1,crval1,cd1_1,crpix2,crval2,cd2_2;


  if(argc!=3){
    fprintf(stderr,"Usage : %s input output\n",argv[0]);
    exit(0);
  }

  if((fpd=fopen("extract.dat","r"))==NULL){
     fprintf(stderr,"Can not open file: extract.dat\n Use default value.\n");
   }
  else{
    for(k=0;k<9;k++){
      if(fscanf(fpd,"%f",&w[k])!=1){
        fprintf(stderr,"Wrong format\n");
        exit(1);
      }
    }
   fclose(fpd);
  }

  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);
  if(fits_read_key(fp, TSTRING, "CTYPE1", ctype1, NULL, &status)) keys=0;
  if(keys){if(fits_read_key(fp, TSTRING, "CUNIT1", cunit1, NULL, &status)) keys=0;}
  if(keys){if(fits_read_key(fp, TFLOAT, "CRPIX1", &crpix1, NULL, &status)) keys=0;}
  if(keys){if(fits_read_key(fp, TFLOAT, "CRVAL1", &crval1, NULL, &status)) keys=0;}
  if(keys){if(fits_read_key(fp, TFLOAT, "CD1_1", &cd1_1, NULL, &status)) keys=0;}
  if(keys){if(fits_read_key(fp, TSTRING, "CTYPE2", ctype2, NULL, &status)) keys=0;}
  if(keys){if(fits_read_key(fp, TSTRING, "CUNIT2", cunit2, NULL, &status)) keys=0;}
  if(keys){if(fits_read_key(fp, TFLOAT, "CRPIX2", &crpix2, NULL, &status)) keys=0;}
  if(keys){if(fits_read_key(fp, TFLOAT, "CRVAL2", &crval2, NULL, &status)) keys=0;}
  if(keys){if(fits_read_key(fp, TFLOAT, "CD2_2", &cd2_2, NULL, &status)) keys=0;}
  status=0;
  fprintf(stderr,"%ld x %ld format ",naxes[0],naxes[1]);
  if((naxes[0]>LINEPIX)||(naxes[1]>LINEPIY)){
    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);
    for(j=0;j<naxes[0];j++) z[i][j]=buffer[j];
    fpixel+=naxes[0];
  }
  if(fits_close_file(fp, &status))
    printerror(status);
  fprintf(stderr,"OK\n");

  if(strcmp(argv[1],argv[2])==0) remove(argv[1]);
  naxes[1]/=9;crpix2=(crpix2+4)/9.;cd2_2*=9.;
  fprintf(stderr,"Write %s  ... ",argv[2]);
  status=0;
  if (fits_create_file(&fp, argv[2], &status))
    printerror(status);
  if (fits_create_img(fp, bitpix, naxis, naxes, &status))
    printerror(status);
  fprintf(stderr,"%ld x %ld format ",naxes[0],naxes[1]);
  if(keys){
    if (fits_write_key(fp, TSTRING, "CTYPE1", ctype1, "", &status))
      printerror(status);
    if (fits_write_key(fp, TSTRING, "CUNIT1", cunit1, "", &status))
      printerror(status);
    if (fits_write_key(fp, TFLOAT, "CRPIX1", &crpix1, "", &status))
      printerror(status);
    if (fits_write_key(fp, TFLOAT, "CRVAL1", &crval1, "", &status))
      printerror(status);
    if (fits_write_key(fp, TFLOAT, "CD1_1", &cd1_1, "", &status))
      printerror(status);
    if (fits_write_key(fp, TSTRING, "CTYPE2", ctype2, "", &status))
      printerror(status);
    if (fits_write_key(fp, TSTRING, "CUNIT2", cunit2, "", &status))
      printerror(status);
    if (fits_write_key(fp, TFLOAT, "CRPIX2", &crpix2, "", &status))
      printerror(status);
    if (fits_write_key(fp, TFLOAT, "CRVAL2", &crval2, "", &status))
      printerror(status);
    if (fits_write_key(fp, TFLOAT, "CD2_2", &cd2_2, "", &status))
      printerror(status);
  }
  fpixel=1;
  nelements=naxes[0];
  for(i=0;i<naxes[1];i++){
    for(j=0;j<naxes[0];j++){
      buffer[j]=0.;
      for(k=0;k<9;k++) buffer[j]+=z[i*9+k][j]*w[k];
    }

    if (fits_write_img(fp, TFLOAT, fpixel, nelements, buffer, &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 */
}