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

//	The purpose of sepResDat is to extract the data section from responsivity files.  For each responsivity file, a file with the same
//	name but with a .DATA extension is created that contains only two columns of data: the wavelength and the responsivity.
//  (KL) You need to:
//		1) Create a "temp" file that has a list of all the file names you want to work with in a given responsivity directory.
//		2) Run this inside the responsivity directory.

#define		LENGTH		80
#define		TEMPOUT		"ls *.ag2 > temp"
#define		DELTEMP		"rm -f temp" 
#define		DATAEXT		".DATA"
#define		DATAFIELD	"Data:"
#define		DATAFIELDLEN	5
#define		SMALL		4

//      When 'fget'-ing a line from a file, often the last character read in is a newline.  This routine converts the newline to a null
//      termination.  The reason for this is that often string routines from string.h require that the strings passed to them are null
//      terminated.  Odd behavior can occur otherwise.

void newToNull(char array[])
{
	char *ptr = array;

	//	it would be more robust here to compare this against null also so that ptr does not overrun the array bounds.  However since
	//	the arrays that are passed to this will always end in the newline, this seems ok...

	while (*ptr != '\n')
		++ptr;

	*ptr = '\0';
}

void getData(char fileName[], char julStr[])
{
	char UT[SMALL], line[LENGTH], dataFileName[LENGTH];
	FILE *dataFile, *writeData;
	float wavelength, responsivity, dummy1, dummy2;

	//	generates the data file name same as original but with '.DATA' extension
	strcpy(dataFileName, fileName);
	strcat(dataFileName, DATAEXT);

	dataFile = fopen(fileName, "r");	//	open the data file, read past header info to get the data
	fgets(line, LENGTH, dataFile);
	while (strncmp(line, DATAFIELD, DATAFIELDLEN)) 	//	find the 'Data:' line
		fgets(line, LENGTH, dataFile);
	
	//	the data section of these files have four columns of data, the first and second of which contain the wavelength and responsivity
	//	respectively.  The third and fourth columns are not used here and a just read into dummy variables.
	fscanf(dataFile, "%f %f %f %f", &wavelength, &responsivity, &dummy1, &dummy2);		//	read the first data line
	writeData = fopen(dataFileName, "w");
	printf("Creating file: %s\n", dataFileName);
	while (!feof(dataFile)) {
		fprintf(writeData, "%.2f %.5f\n", wavelength, responsivity);
		fscanf(dataFile, "%f %f %f %f", &wavelength, &responsivity, &dummy1, &dummy2);
	}
	fprintf(writeData, "%.2f %.5f\n", wavelength, responsivity);
	fclose(dataFile);
	fclose(writeData);
}

void writeDataFiles()
{
	FILE *fileList;
	char fileName[LENGTH], julStr[SMALL];

	system(TEMPOUT);
	fileList = fopen("temp", "r");		//	'temp' contians a list of all the file names with extension .ASR (in this case, uses the
	fgets(fileName, LENGTH, fileList);	//	other instrument abbreviations as appropriate.  It should be noted that this executable should
	while (!feof(fileList)) {		//	exist in the /Resp/Final directory of each instrument.   
		newToNull(fileName);
		getData(fileName, julStr);
		fgets(fileName, LENGTH, fileList);
	}
	fclose(fileList);
	system(DELTEMP);	
}

int main()
{
	writeDataFiles();
	return 0;
}