// Prings Special K
//
// prings_special_k
//
// Prings Special K
//
// 
//
// Inputs:    4
// Outputs:   2
// Constants: 2


#include "ts.h"

typedef struct {
    uint_t k1;
    uint_t k2;
} ts_prings_special_k_params_t;

ts_parameter_t const ts_prings_special_k_p = { .n_inputs = 4, .n_outputs = 2, .n_constants = 2, .params_size = sizeof(ts_prings_special_k_params_t) };

uint_t ts_prings_special_k_offset( ts_constant_t const *c )
{
	( void )c;
	return ( c ? ((ts_prings_special_k_params_t *)c)->k1 > 0 && ((ts_prings_special_k_params_t *)c)->k2 > 0 ? ((ts_prings_special_k_params_t *)c)->k1 + ((ts_prings_special_k_params_t *)c)->k2 - 2 : 0 : 0 );
}

int ts_prings_special_k(
	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_prings_special_k_p );
	if ( !c ) return -1;
	uint_t k1 = ((ts_prings_special_k_params_t *)c)->k1;
	uint_t k2 = ((ts_prings_special_k_params_t *)c)->k2;
	if (k1 == 0 || k2 == 0) return -1;

	fp_t ema = 0;
	fp_t ema_a = 1.0 / (fp_t)k2;

	for (uint_t j = 0; j < n && j < k1 - 1; ++j) { y[0][j] = 0; y[1][j] = 0; }
	for( uint_t i = k1 - 1; i < n; ++i )
	{
		fp_t ll = ts_l( x, i );
		for( uint_t j = 1; j < k1; ++j )
		{
			fp_t v = ts_l( x, i - j );
			if( v < ll ) ll = v;
		}

		fp_t hh = ts_h( x, i );
		for( uint_t j = 1; j < k1; ++j )
		{
			fp_t v = ts_h( x, i - j );
			if( v > hh ) hh = v;
		}

		fp_t raw = ( hh != ll ) ? 100.0 * ( ts_c( x, i ) - ll ) / ( hh - ll ) : 0;

		if( i == k1 - 1 )
		{
			ema = raw;
		}
		else
		{
			ema = ema + ema_a * ( raw - ema );
		}

		y[0][i] = ema;

		if( i >= k1 + k2 - 2 )
		{
			fp_t d_sum = 0;
			for( uint_t j = 0; j < k2; ++j )
			{
				d_sum += y[0][i - j];
			}
			y[1][i] = d_sum / (fp_t)k2;
		}
	}
	return 0;
}