//OBTcomp.c, to compare brightness temperature estimates between the AERI and Peter Minnett's IRTs.

#include <dos.h>
#include <stdio.h>
#include <string.h>

#define dev (1)		//development flag, prints working values


FILE *fp1,*fp2,*fp3;

void openfiles(void);		//procedure prototypes
void readfile (void);
double convertime(char *);

char[80] date, infile1name, infile2name, outfilename, suffix;
int runmode;

main()
{
getinquiry(void);
openfiles(void);
while (!(EOF(fp1))
	readfile (void);
closefiles(void);
}

/*-----------------------------------------------------------*/

void getinquiry (void)
{
char [5] y1,y2,d1,d2,m1,m2, day, month, year;
int yy,mm,dd;

printf("Please enter the date for your SST comparison enquiry, in the form YYMMDD\n");
scanf("%s", &date);

sscanf(date, "%c%c%c%c%c%c" &y1,&y2, &m1, &m2, &d1, &d2);
sprintf(year, "%c%c", y1,y2);
sprintf(month, "%c%c", m1, m2);
sprintf(day, "%c%c", d1, d2);

mm = atoi(month);
yy = atoi (year);
dd = atoi (day);

//check date integrity
if (yy!=96)
	{
	printf("Sorry, only 1996 data is available\n")
	exit(0);
	}
if ((mm<0) || (mm>12))
	{
	printf("Input error in month field\n");
	exit(0);
	}
if ((dd<0) || (dd>31))
	{
	printf("Input error in day field\n");
	exit(0);
	}

printf("Please enter the AERI datafile suffix (s55,w35, etc)\n");
scanf("%s", &suffix);
sprintf(infilename1,"ae%s.%s", date, suffix);
sprintf(infilename2, "Peter's filename");
sprintf(outfilename, "AT%s.%s", date, suffix);

printf("Please select operation mode: \n")
printf("\n")
printf("\t1: One IRT measurement only\n");
printf("\t2: Averaged IRT measurement\n");

scanf("%d", &runmode);

}
/*-----------------------------------------------------------*/
void openfiles()

char[200] chaff;

{
sprintf(outfilename, "OP%s.%s", date, suffix);
fp1 = fopen(infile1name,"r");
if (fp1 == NULL)
	{
	printf("Sorry, could not open file %s\n", infile1name);
	exit(0);
	}
fgets(chaff, 199,fp1);		//remove header lines
fgets(chaff, 199, fp1);

fp2 = fopen (infile2name, "r");
if (fp2 == NULL)
	{
	printf("Sorry, could not open file %s\n", infile2name);
	exit(0);
	}
fp3 = fopen (outfilename, "w");
if (fp3 == NULL)
	printf("Sorry, could not open file %s\n", outfilename);
}
/*-----------------------------------------------------------*/

void readfile (void)
{
char [200]	aeribuffer, irtbuffer1, irtbuffer2;
char[400] 	outputbuff;
char[15] 	aeridate, aeritime, irtdate, irttime, irt2date, irt2time;
char[5] 		aeday, aemonth, aeyear, irday, irmonth, iryear;	
char 		aey1, aey2, aed1, aed2, aem1, aem2;			
char		 iry1, iry2, ird1, ird2, irm1, irm2;		
double		ModyFraction, UTCHour, AvWavenumber, Rad, BTempK, BTempC;
int aeyy, aemm, aedd, iryy, irmm, irdd;								
double decaetime, decirtime, decirt2time;		//decimal conversion for time
double difftime1, difftime2;			//the difference between AERI and IRT time 
double 	aeritemp, irttemp, irt2temp;
long int aedateint, aetimeint;							//for each row


fgets(aeribuffer,199,fp1);		//get the first row of AERI file
sscanf(aeribuffer, "%ld, %ld, %lf, %lf, %lf, %lf, %lf, %lf", &aedateint, &aetimeint, &ModyFraction, &UTCHour, &AvWavenumber, &Rad, &BTempK, &BTempC);			
									//extract variables

if(dev) printf("Date is %ld, Time is %ld, ModyFraction is %lf, UTCHour is %lf, AvWavenumber is %lf, Rad is %lf, BTempK is %lf, BTempC is %lf", aedateint, aetime, ModyFraction, UTCHour, AvWavenumber, Rad, BTempK, BTempC);
sprintf(aedate, "%ld", aedateint);
	
sscanf(aedate, "%c%c%c%c%c%c" &aey1,&aey2, &aem1, &aem2, &aed1, &aed2);
sprintf(aeyear, "%c%c", aey1,aey2);
sprintf(aemonth, "%c%c", aem1, aem2);
sprintf(aeday, "%c%c", aed1, aed2);

aemm = atoi(aemonth);
aeyy = atoi (aeyear);
aedd = atoi (aeday);


fgets(irtbuffer,199,fp2);
sscanf(irtbuffer, "%s, %s, %d, %d, %lf, %ld", irtdate, irttime, &irttemp);

sscanf(irdate, "%c%c%c%c%c%c%c%c%c%c" &chaff, &chaff, &iry1,&iry2, &chaff, &irm1, &irm2, &chaff, &ird1, &ird2);
sprintf(iryear, "%c%c", iry1,iry2);
sprintf(irmonth, "%c%c", irm1, irm2);
sprintf(irday, "%c%c", ird1, ird2);

irmm = atoi(irmonth);
iryy = atoi (iryear);
irdd = atoi (irday);

if ((irmm == aemm)&&(iryy == aeyy)&&(irdd == aedd))
	{
	printf("Successful date match achieved. Stand by...\n");
	}
else
	{
	printf("Unsuccessful date match. Exiting...\n");
	exit(0);
	}

decaetime = UTCHour;
decirtime = converttime(irtime);

printf("Decimal time conversion complete: first AERI data is for %lf\n", decaetime);
printf("                                                          first IRT data is for %lf\n", decirtime);

difftime1 = decaetime - decirtime;
if((difftime1) < 0)
	{	
	printf("Sorry, this date will require manual manipulation\n");
	exit(0);
	}
while (TRUE) do
	{
	fgets(irtbuffer,199,fp2);
	sscanf(irtbuffer, "%s, %s, %d, %d, %lf, %ld", irtdate, irttime, &irttemp);
	decirtime = converttime(irtime);
	difftime1 = decaetime - decirtime;
	fgets(irtbuffer2,199,fp2);
	sscanf(irtbuffer2, "%s, %s, %d, %d, %lf, %ld", irt2date, irt2time, &irt2temp);
	decirt2time = converttime(irt2time);
	difftime2 = decaetime - decirt2time;
	if (difftime2 < 0)
		break;
	}
if (abs(difftime1)>abs(difftime2))
	fprintf(fp3, "%ld \t %ld \t %lf \t %lf\t %lf \t %lf\t %lf\t %lf\t %lf\t %lf\t %lf\t", aedateint, aetimeint, ModyFraction, UTCHour, AvWavenumber, Rad, BTempK, aetimeint, BTempC,irt2temp, irt2time);

else
	fprintf(fp3, "%ld \t %ld \t %lf \t %lf\t %lf \t %lf\t %lf\t %lf\t %lf\t %lf\t  %lf\t", aedateint, aetimeint, ModyFraction, UTCHour, AvWavenumber, Rad, BTempK, aetimeint, BTempC,irttemp, irttime);

	}

/*-----------------------------------------------------------*/
double convertime(char *intime)

char h1, h2, min1, min2, s1, s2, chaff;		//single characters for reading in time string.	
char[5] hour, min, sec;		//hours, minutes and seconds in string form 
int hh, minmin, ss;		//hours, minutes and seconds as ints 

sscanf(intime, "%c%c%c%c%c%c%c%c " &aeh1,&aeh2, &chaff, &aemin1, &aemin2, &chaff, &aes1, &aes2);								//chaff colons.
sprintf(aehour, "%c%c", h1,h2);
sprintf(aemin, "%c%c", min1, min2);
sprintf(aesec, "%c%c", s1, s2);

aehh = atoi(hour);
aeminmin = atoi (min);
aess = atoi (sec);

return(hh + double(minmin)/60 + double(ss)/3600);

/*-----------------------------------------------------------*/
void closefiles()

fclose(fp1);
fclose(fp2);
fclose(fp3);

printf("Files successfully closed\n");

/*-----------------------------------------------------------*/