// Volume Weighted Moving Average
//
// volume_weighted_moving_average
//
// Volume Weighted Moving Average
//
// 
//
// Inputs:    5
// Outputs:   1
// Constants: 1


#include "ts.h"

typedef struct {
    uint_t k;
} ts_volume_weighted_moving_average_params_t;

ts_parameter_t const ts_volume_weighted_moving_average_p = { .n_inputs = 5, .n_outputs = 1, .n_constants = 1, .params_size = sizeof(ts_volume_weighted_moving_average_params_t) };

uint_t ts_volume_weighted_moving_average_offset( ts_constant_t const *c )
{
	( void )c;
	return ( c ? ((ts_volume_weighted_moving_average_params_t *)c)->k > 0 ? ((ts_volume_weighted_moving_average_params_t *)c)->k - 1 : 0 : 0 );
}

int ts_volume_weighted_moving_average(
	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_volume_weighted_moving_average_p );
	if ( !c ) return -1;
    uint_t k = ((ts_volume_weighted_moving_average_params_t *)c)->k;
    if (k == 0 || n < k) return -1;

    fp_t cv_sum = 0;
    fp_t v_sum = 0;

    for( uint_t j = 0; j < k; ++j )
    {
        cv_sum += ts_c(x, j) * ts_v(x, j);
        v_sum += ts_v(x, j);
    }

    y[0][k - 1] = (v_sum != 0) ? cv_sum / v_sum : 0;

    for( uint_t i = k; i < n; ++i )
    {
        cv_sum += ts_c(x, i) * ts_v(x, i) - ts_c(x, i - k) * ts_v(x, i - k);
        v_sum += ts_v(x, i) - ts_v(x, i - k);
        y[0][i] = (v_sum != 0) ? cv_sum / v_sum : 0;
    }
	return 0;
}