// Guard against publication dates that sit in the future.
//
// pub_date_effective is what the autonomy coordinator uses to derive a
// prediction's information_cutoff (max pub_date_effective across an event's
// articles), so a single bogus feed date drags the cutoff forward and quietly
// breaks evidence-cutoff enforcement and outcome scoring. Production currently
// has exactly one such row, but one is enough to poison an event.
//
// Tolerance: 48 hours. It has to swallow the legitimate cases —
//   * date only strings ("2026-08-29") are stored as midnight UTC, and a
//     publisher in UTC+14 can legitimately stamp tomorrow's date,
//   * feeds that emit local time without an offset, worst case ~14h ahead,
//   * modest clock skew on the publisher's box.
// 48h covers all of that with room to spare while still catching anything
// genuinely wrong — the offending production row is about four months out.
const DEFAULT_TOLERANCE_MS = 48 * 60 * 60 * 1000;

function toleranceMs() {
  const hours = Number(process.env.INGEST_FUTURE_PUB_DATE_HOURS);
  if (Number.isFinite(hours) && hours > 0) return hours * 60 * 60 * 1000;
  return DEFAULT_TOLERANCE_MS;
}

// Returns { ok, value, skewMs, toleranceMs }. `value` is null when the date is
// implausible so the caller can fall back to ingestion time. The article itself
// is never dropped for this — a bad date is not a bad article.
function checkPubDate(value, now = Date.now(), tolerance = toleranceMs()) {
  if (!value) return { ok: true, value: null, skewMs: 0, toleranceMs: tolerance };

  const parsed = new Date(value).getTime();
  if (Number.isNaN(parsed)) return { ok: true, value: null, skewMs: 0, toleranceMs: tolerance };

  const skewMs = parsed - now;
  if (skewMs > tolerance) {
    return { ok: false, value: null, skewMs, toleranceMs: tolerance };
  }

  return { ok: true, value, skewMs, toleranceMs: tolerance };
}


// Same check, but it also does the shouting. Keeps ingest.js readable and makes
// sure every clamp lands in the logs with the source and the offending value.
function guardEffectivePubDate(pubDate, fallback, context = {}) {
  const verdict = checkPubDate(pubDate);
  if (verdict.ok) return pubDate || fallback;

  const days = (verdict.skewMs / 86400000).toFixed(1);
  console.warn(
    `[ingest] refusing future pub date from "${context.source || 'unknown source'}": ${pubDate} is ${days} days ahead ` +
    `(tolerance ${Math.round(verdict.toleranceMs / 3600000)}h) — pub_date_effective falls back to ${fallback}. url=${context.url || 'n/a'}`
  );

  return fallback;
}

module.exports = {
  checkPubDate,
  guardEffectivePubDate,
  DEFAULT_TOLERANCE_MS,
};