#include "torlinkc/util/date_parse.hpp"

#include <cstring>
#include <ctime>

#include <curl/curl.h>

namespace torlinkc {

std::optional<std::int64_t> parseDateToUnixSeconds(const std::string& s) {
  if (s.empty()) return std::nullopt;

  // ISO 8601 first: curl_getdate() doesn't understand "2024-01-15T00:00:00Z".
  // Fractional seconds and a timezone suffix (if any) are ignored and the
  // result treated as UTC -- matching JS's Date.parse for the 'Z'-suffixed
  // ISO dates these APIs actually send; none of them emit a non-UTC offset.
  {
    std::tm tm{};
    if (strptime(s.c_str(), "%Y-%m-%dT%H:%M:%S", &tm) != nullptr) {
      const time_t t = timegm(&tm);
      if (t != static_cast<time_t>(-1)) return static_cast<std::int64_t>(t);
    }
  }

  const time_t t = curl_getdate(s.c_str(), nullptr);
  if (t != static_cast<time_t>(-1)) return static_cast<std::int64_t>(t);
  return std::nullopt;
}

}  // namespace torlinkc