// Starc Upper
//
// starc_upper
//
// STARC Upper Band
//
// 
//
// Inputs:    4
// Outputs:   1
// Constants: 2


#include <math.h>
#include "ts.h"

typedef struct {
    uint_t k;
    fp_t mult;
} ts_starc_upper_params_t;

ts_parameter_t const ts_starc_upper_p = { .n_inputs = 4, .n_outputs = 1, .n_constants = 2, .params_size = sizeof(ts_starc_upper_params_t) };

uint_t ts_starc_upper_offset( ts_constant_t const *c )
{
	( void )c;
	return ( c ? ((ts_starc_upper_params_t *)c)->k : 0 );
}

int ts_starc_upper(
	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_starc_upper_p );
	if ( !c ) return -1;
    uint_t k = ((ts_starc_upper_params_t *)c)->k;
    fp_t mult = ((ts_starc_upper_params_t *)c)->mult;
    if ( k == 0 || k >= n ) return -1;

    for ( uint_t i = k; i < n; ++i )
    {
        fp_t tr_sum = 0;
        for ( uint_t j = 0; j < k; ++j )
        {
            uint_t idx = i - k + 1 + j;
            fp_t tr = fmax( ts_h( x, idx ) - ts_l( x, idx ), fmax( fabs( ts_h( x, idx ) - ts_c( x, idx - 1 ) ), fabs( ts_l( x, idx ) - ts_c( x, idx - 1 ) ) ) );
            tr_sum += tr;
        }
        fp_t atr = tr_sum / (fp_t)k;

        fp_t sum = 0;
        for ( uint_t j = 0; j < k; ++j )
        {
            sum += ts_c( x, i - k + 1 + j );
        }
        fp_t mean = sum / k;

        y[0][i] = mean + mult * atr;
    }
	return 0;
}