/* $Id: timeResFromData.c,v 1.1 2010/08/31 10:32:55 budnik Exp $ */

/** @file timeResFromData.c
*   @brief Function to get CDAWEB dataset sampling times from data files
*/
#include <stdio.h>
#include <stdlib.h>
#include <cdf.h>
#include <string.h>
#include <time.h>
#include <math.h>

#define fileName "temp.cdf"
#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);
}

void find_min(int* delta, int nRecs, int minFalse, int* minVal)
{
	int i, n, min;

	n = 1;
	i = 0;
	while (abs(delta[i]) <= minFalse) i++;
	if (i < nRecs) {
		min = abs(delta[i]); 
		// printf(" first MIN %d \n", min);
		for (i = 1; i < nRecs; i++) {
			//   printf(" delta %d \n", delta[i]);
			if (delta[i] == min) n++;
			if (delta[i] < min && delta[i] > minFalse) {
					min = delta[i];
					n = 1;
			}
		}
	} else {
		min = -10;
		n = nRecs;
	}
	
	minVal[0] = min;
	minVal[1] = n; 
	printf(" MIN %d %d\n", min, n);
}

int main(int argc, char *argv[])
{
	long RecStart = 0, RecCount, 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 *delta;
	int i, minFalse = 0, numEnough;
	int min[2] = {0, 0};
	char attrValue[300];
	float Sampling;
	double epoch16[2], dbl_value, dbl_value_;
	long year, month, day, hour, minute, sec, msec, mksec, nsec, psec; 
	long long *int_value;
    
/*********************** 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);  
		//     if (datatype == CDF_EPOCH16)  break;
	}
	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 < 10) {
		fprintf(stdout," %d\n", badFile);
		exit (0);
	}
	
	if ( datatype == CDF_TIME_TT2000 ) {
		int_value = (long long *) malloc (sizeof(long long) * (CDFmaxRec+1));
		/******************* Get Epoch  *************************/
		if ((cstatus = CDFlib (SELECT_,
								zVAR_, varN,
								zVAR_RECNUMBER_, RecStart,
								zVAR_RECCOUNT_, CDFmaxRec+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)* (CDFmaxRec+1)*((datatype == CDF_EPOCH16)+1)); 
		/******************* Get Epoch  *************************/
		if ((cstatus = CDFlib (SELECT_,
								zVAR_, varN,
								zVAR_RECNUMBER_, RecStart,
								zVAR_RECCOUNT_, CDFmaxRec+1,
								zVAR_RECINTERVAL_, RecInt,
								zVAR_DIMINDICES_, indices,
								zVAR_DIMCOUNTS_, counts,
								zVAR_DIMINTERVALS_, intervals,
								GET_, zVAR_HYPERDATA_, value,  NULL_)) != CDF_OK) 
															cdf_handle_error (cstatus);
	}
	

  
	delta = (int *)malloc(sizeof(int)* CDFmaxRec);
	for (i = 1; i < CDFmaxRec+1; i++)  
	{
		if (datatype == CDF_TIME_TT2000) {
			dbl_value_ = CDF_TT2000_to_UTC_EPOCH(int_value[i-1]);
			dbl_value = CDF_TT2000_to_UTC_EPOCH(int_value[i]);
			delta[i-1] = (int)(dbl_value - dbl_value_ + 50)/100;
		}
		else {
			if (datatype == CDF_EPOCH16) {
				epoch16[0] = value[2*(i-1)];
				epoch16[1] = value[2*(i-1)+1];
				EPOCH16breakdown(epoch16, &year, &month, &day, &hour, &minute, &sec, &msec, &mksec, &nsec, &psec);
				value[i-1] = computeEPOCH(year, month, day, hour, minute, sec, msec);
				epoch16[0] = value[2*i];
				epoch16[1] = value[2*i+1];
				EPOCH16breakdown(epoch16, &year, &month, &day, &hour, &minute, &sec, &msec, &mksec, &nsec, &psec);
				value[i] = computeEPOCH(year, month, day, hour, minute, sec, msec);
			}
			delta[i-1] = (int)(value[i] - value[i-1] + 50)/100;
		}
	}
	// fprintf(stdout,"value %f\n", value[11]-value[10]);
	if (datatype == CDF_TIME_TT2000) free(int_value); 
	else free(value);
	// fprintf(stdout,"delta %d\n", delta[0]);
	numEnough = CDFmaxRec/10; 
	while (min[1] <  numEnough) {
		fprintf(stdout,"minFalse %d\n", minFalse);
		find_min(delta, CDFmaxRec, minFalse, min); 
		minFalse = min[0];
	}
     
	free(delta); 
	if ((cstatus = CDFlib(CLOSE_, CDF_, NULL_)) != CDF_OK)
										cdf_handle_error (cstatus);

	//   fprintf(stdout,"%d %f\n",min[1], (float)min[0]/100.0);
	fprintf(stdout,"%f\n",(float)min[0]/10.0); 
}