// Vortex Indicator
//
// vortex_indicator
//
// Vortex Indicator
//
// 
//
// Inputs:    4
// Outputs:   2
// Constants: 1


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

typedef struct {
    uint_t k;
} ts_vortex_indicator_params_t;

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

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

int ts_vortex_indicator(
	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_vortex_indicator_p );
	if ( !c ) return -1;
	uint_t k = ((ts_vortex_indicator_params_t const *)c)->k;
	if (k == 0 || n < k) return -1;

	for( uint_t i = k; i < n; ++i )
	{
		fp_t sum_vm_plus = 0;
		fp_t sum_vm_minus = 0;
		fp_t sum_tr = 0;

		for( uint_t j = 0; j < k; ++j )
		{
			uint_t idx = i - k + 1 + j;
			fp_t vm_plus = fabs( ts_h( x, idx ) - ts_l( x, idx - 1 ) );
			fp_t vm_minus = fabs( ts_l( x, idx ) - ts_h( x, idx - 1 ) );
			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 ) ) ) );
			sum_vm_plus += vm_plus;
			sum_vm_minus += vm_minus;
			sum_tr += tr;
		}

		y[0][i] = sum_tr != 0 ? sum_vm_plus / sum_tr : 0;
		y[1][i] = sum_tr != 0 ? sum_vm_minus / sum_tr : 0;
	}
	return 0;
}