#include <Rcpp.h>

using namespace Rcpp;

// [[Rcpp::export]]

NumericVector ww_calc_cpp(NumericVector times, double winlen_hours, bool allow_overlap, double tstep_secs) {

int n = times.size();

if (n < 2) return NumericVector(0);

std::vector<double> detected;

int current_index = 0; // was k

int next_start_index = 0; // for non-overlapping windows

double winlen_secs = winlen_hours * 3600.0;

while (current_index < n - 1) {

double start_time = times[current_index];

double current_time = start_time;

// Assign next_time safely

double next_time = times[current_index + 1];

while ((next_time - current_time) <= tstep_secs && current_index < n - 1) {

current_index += 1;

if ((next_time - start_time) >= winlen_secs) {

detected.push_back(start_time);

break;

}

current_time = times[current_index];

// update next_time safely

if (current_index + 1 < n) next_time = times[current_index + 1];

else break;

}

next_start_index += 1;

current_index = allow_overlap ? current_index + 1 : next_start_index;

}

return wrap(detected);

}