/***************************************************************************
 Name: mgdrlite_toIntel.c                                              
 Function: Read unformatted Quickscat wind-lite  binary data in "Big Endian"     
           format and convert it to Intel based "Little Endian" binary file
      
 Input : unformatted wind data in   SUN binary "Big Endian" file 
 Output: unformatted wind data in INTEL binary "Little Endian" file:
         ddd hh mm lattitude longitude windspeed winddir
         qual_flag rainflag blank1 blank2 blank3

 USAGE: mgdrlite_toIntel input_file  outputfile
 NOTE:  
        
 @author Zihou Wang and Jeffrey Augenbaum                                   
 version 1.0   07/25/2002                            
 ******************************************************************************/

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

void swapSample(short int *samp);

#define len 76    

main(int argc, char *argv[]) {

  char *prog;
  static char usage[] = "Usage : %s inputMGDRFile outputWindFile\n";

FILE *fin, *fout;
char fout_name[80];
char fin_name[80];
int f, head_flag,totrecs,reclen;
  int nrec, i;

  short int latarr[len],blanks[len],
        time_arr[4],wind[len];
  unsigned short int lonarr[len],dir[len],qual_flag[len];
  short int rainflag_mudh[len];
 
  /*  check arguments   */
  if (argc != 3) {
     printf(usage,argv[0]);
     exit(1);
  } 

/* get output file name,  */

strcpy(fout_name,argv[2]);
fout=fopen(fout_name,"w");

  /* open unformatted wind data file */
  strcpy(fin_name,argv[1]);
  fin = fopen(fin_name,"r");
  if (fin == NULL){
    printf("read %s failed\n",fin_name);
    exit(1);
  }
  /* printf("read %s ok\n",fin_name); */

/*
  printf("DDD HH MM %6s%6s%6s%6s%6s%6s%6s%6s%6s\n","lat","Long",
         "speed","dir", "qual","rain","blank","blank","blank"); 
*/
  /* read records in the input file */

  nrec = 0;  
  while( fread(time_arr,sizeof(short int),4,fin)) {
    nrec++;
	 swapSample(&time_arr[0]);
         swapSample(&time_arr[1]);
         swapSample(&time_arr[2]);
	 swapSample(&time_arr[3]);

/* Write out new time array for single record */
f=fwrite(time_arr,sizeof(short int),4,fout);
/*
 printf("%3d %2d %2d\n", time_arr[0],time_arr[1], time_arr[2]);
*/

/* Read in lat, lon, wind, dir, selection index */
    fread(latarr,sizeof(short int),len,fin); 
    fread(lonarr,sizeof(unsigned short int),len,fin); 
    fread(qual_flag,sizeof(unsigned short int),len,fin); 
    fread(wind,sizeof(short int),len,fin); 
    fread(dir,sizeof(unsigned short int),len,fin); 
    fread(rainflag_mudh,sizeof(short int),len,fin);
    fread(blanks,sizeof(short int),len,fin); 
    fread(blanks,sizeof(short int),len,fin); 
    fread(blanks,sizeof(short int),len,fin); 

    
    for(i=0; i<len; i++) {

         swapSample(&latarr[i]);
         swapSample(&lonarr[i]);
         swapSample(&wind[i]);
         swapSample(&dir[i]);
         swapSample(&qual_flag[i]);
         swapSample(&rainflag_mudh[i]);
         swapSample(&blanks[i]);
/*
      printf("%3d %2d %2d ", time_arr[0],
          time_arr[1], time_arr[2]);   
      printf("%6d%6d%6d%6d%6d%6d%6d%6d%6d\n",latarr[i],lonarr[i],
           wind[i],dir[i], qual_flag[i], rainflag_mudh[i],
           blanks[i],blanks[i],blanks[i]); 
*/
    }
/*----------------------- loop III end */


f=fwrite(latarr,sizeof(short int),len,fout);
f=fwrite(lonarr,sizeof(unsigned short int),len,fout);
f=fwrite(qual_flag,sizeof(unsigned short int),len,fout);
f=fwrite(wind,sizeof(short int),len,fout);
f=fwrite(dir,sizeof(unsigned short int),len,fout);
f=fwrite(rainflag_mudh,sizeof(short int),len,fout);
f=fwrite(blanks,sizeof(short int),len,fout);
f=fwrite(blanks,sizeof(short int),len,fout);
f=fwrite(blanks,sizeof(short int),len,fout);

/*------------------------------------ loop II end */


  } 

  printf("Total records: %d\n", nrec);

fclose(fin);
fclose(fout);
  return 0;
}

void swapSample(short int *samp)
{
  char temp, *p, *q;

  if (sizeof(short int) != 2){
    printf("swap sample works only with two byte integers \n");
    exit(-1);
  }

  p = (char *)samp;
  q = p+1;

  temp = *p;
  *p = *q;
  *q = temp;

} /* swap sample */