// T3
//
// t3
//
// T3 Moving Average
//
// 
//
// Inputs:    1
// Outputs:   1
// Constants: 0


#include "ts.h"

ts_parameter_t const ts_t3_p = { .n_inputs = 1, .n_outputs = 1, .n_constants = 0, .params_size = 0 };

uint_t ts_t3_offset( ts_constant_t const *c )
{
	( void )c;
	return ( 0 );
}

int ts_t3(
	fp_t * const *y, uint_t y_n,
	fp_t const * const *x, uint_t x_n,
	uint_t n, ts_constant_t const *c
)
{
	TS_PROLOGUE( ts_t3_p );
	(void)c;
	if (n == 0) return -1;

	uint_t k = 5;

	fp_t b = 0.7;

	fp_t alpha = 2.0 / ( (fp_t)k + 1.0 );

	fp_t c3 = b;
	fp_t c3m1 = c3 - 1.0;
	fp_t c3m2 = c3 - 2.0;
	fp_t c3m3 = c3 - 3.0;

	fp_t w3 = c3;
	fp_t w2 = -3.0 * c3m1;
	fp_t w1 = 3.0 * c3m1 * c3m2;
	fp_t w0 = -c3m1 * c3m2 * c3m3;

	fp_t ema1 = x[0][0];
	fp_t ema2 = x[0][0];
	fp_t ema3 = x[0][0];

	y[0][0] = x[0][0];

	for( uint_t i = 1; i < n; ++i )
	{
		ema1 = ema1 + alpha * ( x[0][i] - ema1 );
		ema2 = ema2 + alpha * ( ema1 - ema2 );
		ema3 = ema3 + alpha * ( ema2 - ema3 );

		y[0][i] = w3 * ema3 + w2 * ema2 + w1 * ema1 + w0 * x[0][i];
	}
	return 0;
}