/*
 * fftSub.c
 *
 * Functions for initializing and performing FFT on waveforms from
 * the beam profiler.
 *
 *  Created on: Oct 26, 2015
 *      Author: Hovanes Egiyan
 */

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

#include <dbDefs.h>
#include <registryFunction.h>
#include <subRecord.h>
#include <aSubRecord.h>
#include <epicsTypes.h>
#include <epicsTime.h>
#include <epicsExport.h>

#include "ddcmath.h"
#include "fourier.h"

int fftDebug = 10;
/*
 * Initialize records to save PXI data
 */
static long fftInit( aSubRecord *record ) {
/*	if ( fftDebug > 2 ) printf( "Record %s called fftInit(%p)\n", record->name, (void*) record );*/
	return 0;
}

/*
 * Process records to save PXI data
 */
static long fftProcess( aSubRecord *record ) {
/*	if ( fftDebug > 2 ) printf( "Record %s called fftProcess(%p)\n", record->name, (void*) record );*/

	/* INPA will be the record whose transform will need to be computed */
	unsigned nFIFO = record->noa;

	/* the OUTB field is going to be the real part */
	unsigned halfFIFO = record->novb;

	float realPart[nFIFO], imgPart[nFIFO];

	/*	float power[halfFIFO], phase[halfFIFO]; */

	// first copy the input data to vala since vala will be set to float
	memcpy( record->vala, record->a, nFIFO * (sizeof(float)) );

	/*
	 Do fast-fourier transform using the float numbers in vala.
	 The real part will be in valb, the imaginary part will be in valc.
	 */
	fft_float( nFIFO, 0, record->vala, NULL, realPart, imgPart );

	/* Copy real part and imaginary part to B and C output
	 * Only first half is copied since the second half is not determined.
	 */
	memcpy( record->valb, realPart, halfFIFO * (sizeof(float)) );
	memcpy( record->valc, imgPart, halfFIFO * (sizeof(float)) );

	// Calculate the power and the
//	for( unsigned iFIFO = 0; iFIFO < halfFIFO; iFIFO++ ) {
//		power[iFIFO] = sqrt(realPart[iFIFO]*realPart[iFIFO] + imgPart[iFIFO]*imgPart[iFIFO] );
//		if( realPart[iFIFO] > 0 ) {
//			phase[iFIFO] = (float) atan2(imgPart[iFIFO],realPart[iFIFO] ) ;
//		} else {
//			phase[iFIFO] = acos(0.0);
//		}
//	}
	return 0;
}

epicsRegisterFunction( fftInit );
epicsRegisterFunction( fftProcess );