/* $Id: cdf constant sampling from data $ */

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

#define MAX_FILE_NAME_LEN  120

#define badFile -100

/*************************************
   Global variables and structures
**************************************/

long  CDFDims,                                   // Number of dimensions in a CDF file
	CDFVars,                                      // Number of variables in a CDF file
	CDFDimSizes[CDF_MAX_DIMS],                    // Dimension Sizes in a CDF file
	CDFencoding,                                  // Data encoding
	CDFmajority,                                  // Variable majority
	CDFmaxRec,                                    // max Record number
	CDFAttrs;                                     // number of CDF Attributes
//   CDFdatatype;

struct cdfvar {                              // CDF variable structure

	char name[CDF_VAR_NAME_LEN+1];
	long num;                               //variable number
	long datatype;
	long numElem;                           // variable dimensionality
	long recVariance;                       // variable rec Variance
	long dimVariances[CDF_MAX_DIMS];        // # of data values in dimSizes

} cdfVar;

/*--------------------------------------------------------------------------
 *  Handles a CDF error.
 *--------------------------------------------------------------------------*/
void cdf_handle_error(CDFstatus status)
{

	char  message[CDF_STATUSTEXT_LEN+1];

	CDFerror (status, message);              /* Get the appropriate message */
	fprintf  (stderr, "%s\n", message);
	exit(1);

}

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

	char fileName[MAX_FILE_NAME_LEN];

	long RecStart = 0, RecCount = 2, RecInt = 1;

	long indices[1] = {0}, intervals[1] = {1}, counts[1] = {1};
	long varN = -1;  
	long datatype = 0, attrN, maxEntry;
	CDFstatus   cstatus;           // CDF status code
	CDFid id;
	double *value;

	int i, minFalse = 0, numEnough;

	char attrValue[300];

	int sampling;

	double epoch16[2], dbl_value, dbl_value_;
	long year, month, day, hour, minute, sec, msec, mksec, nsec, psec; 
	long long *int_value;

	
	if (argc <= 1) 
		exit(0);                               /* CDF input file name not specified */
	else
		strcpy(fileName, argv[argc-1]);       /* Get the input file name */ 

    
/*********************** Open CDF file *****************************/

	if ((cstatus = CDFopen(fileName, &id))  != CDF_OK)
										cdf_handle_error(cstatus);

 
/*********** treat all vars as zVars with eliminated false dimensionality and get Nrecs **********/
    

	if ((cstatus = CDFlib(SELECT_, CDF_zMODE_, zMODEon2, NULL_)) != CDF_OK)
										cdf_handle_error (cstatus);
	
    while (datatype != CDF_EPOCH && datatype != CDF_EPOCH16 && datatype != CDF_TIME_TT2000){
		varN++;
		if ((cstatus = CDFlib(SELECT_, zVAR_, varN,
									GET_, zVAR_DATATYPE_, &datatype, NULL_)) != CDF_OK)
																	cdf_handle_error (cstatus);  

	}

	fprintf(stdout,"DATATYPE %d %d\n", varN, datatype);
	if ((cstatus = CDFlib(SELECT_, zVAR_, varN,
								GET_, zVAR_MAXREC_, &CDFmaxRec, NULL_)) != CDF_OK)
										cdf_handle_error (cstatus);

	fprintf(stdout,"Max Recs %d\n", CDFmaxRec+1);

	
	if (CDFmaxRec < 3) {

		fprintf(stdout," %d\n", badFile);
		exit (0);
	}
	
	if ( datatype == CDF_TIME_TT2000 ) {

		int_value = (long long *) malloc (sizeof(long long) * (RecCount+1));

		/******************* Get Epoch  *************************/
		if ((cstatus = CDFlib (SELECT_,
								zVAR_, varN,
								zVAR_RECNUMBER_, RecStart,

								zVAR_RECCOUNT_, RecCount + 1,

								zVAR_RECINTERVAL_, RecInt,
								zVAR_DIMINDICES_, indices,
								zVAR_DIMCOUNTS_, counts,
								zVAR_DIMINTERVALS_, intervals,
								GET_, zVAR_HYPERDATA_, int_value,  NULL_)) != CDF_OK) 
															cdf_handle_error (cstatus);
	}
	else {

		value = (double *)malloc(sizeof(double)* (RecCount + 1)*((datatype == CDF_EPOCH16)+1)); 

		/******************* Get Epoch  *************************/
		if ((cstatus = CDFlib (SELECT_,
								zVAR_, varN,
								zVAR_RECNUMBER_, RecStart,

								zVAR_RECCOUNT_, RecCount + 1,

								zVAR_RECINTERVAL_, RecInt,
								zVAR_DIMINDICES_, indices,
								zVAR_DIMCOUNTS_, counts,
								zVAR_DIMINTERVALS_, intervals,
								GET_, zVAR_HYPERDATA_, value,  NULL_)) != CDF_OK) 
															cdf_handle_error (cstatus);
	}

		if (datatype == CDF_TIME_TT2000) {

			dbl_value_ = CDF_TT2000_to_UTC_EPOCH(int_value[0]);
			dbl_value = CDF_TT2000_to_UTC_EPOCH(int_value[1]);

			sampling = (int)(dbl_value - dbl_value_);

		}
		else {
			if (datatype == CDF_EPOCH16) {

				epoch16[0] = value[0];
				epoch16[1] = value[1];

				EPOCH16breakdown(epoch16, &year, &month, &day, &hour, &minute, &sec, &msec, &mksec, &nsec, &psec);

				value[0] = computeEPOCH(year, month, day, hour, minute, sec, msec);
				epoch16[0] = value[2];
				epoch16[1] = value[3];

				EPOCH16breakdown(epoch16, &year, &month, &day, &hour, &minute, &sec, &msec, &mksec, &nsec, &psec);

				value[1] = computeEPOCH(year, month, day, hour, minute, sec, msec);

			}

			sampling = (int)(value[1] - value[0]);

		}

	// fprintf(stdout,"value %f\n", value[11]-value[10]);
	if (datatype == CDF_TIME_TT2000) free(int_value); 
	else free(value);

	if ((cstatus = CDFlib(CLOSE_, CDF_, NULL_)) != CDF_OK)
										cdf_handle_error (cstatus);

	fprintf(stdout,"%f\n",(float)sampling/1000.0); //  in sec.msec

}