// verify-out.mjs — Lag 5: verifisering-UT. Den adversarielle "proev-aa-motbevis"
// + status-gaten som kjoerer ETTER transformasjon (lag 4) og FOER en kandidat-
// endring skrives til en KB-fil. Den fanger regresjons-klassen: en status-paastand
// (GA/preview/versjon/pris) som ble "korrigert" mot en tilfeldig sitert side og
// stille auto-applyet (agentic-retrieval-regresjonen — roadmap §7, §48).
//
// Lagets regel (spec §21): status-paastander flagges ALLTID for operatoer — aldri
// auto-applyet, uansett hvor sikker evidensen ser ut. verify-out er en REN
// klassifiserer: den beregner en verdict og SKRIVER ALDRI (ingen write-util-
// import). Aa applye endringen er gatens jobb, ikke lag 5s.
//
// Konservativ med vilje: ved tvil flagges. Aa over-flagge koster operatoeren et
// blikk; aa under-flagge ga regresjonen. Null avhengigheter (speiler decisions-io).

// --- Status-claim-detektorer -------------------------------------------------

// GA matches case-SENSITIVE for aa unngaa norsk "ga" (preteritum av "gi").
const RE_GA = /\bGA\b/;
const RE_RELEASE = /general(ly)?\s+available|generelt\s+tilgjengelig|\bpublic\s+preview\b|\bprivate\s+preview\b|\bpreview\b|\bbeta\b|deprecat\w*|retir\w*|\bsunset\b|end[-\s]of[-\s]life|\bEOL\b/i;
const RE_VERSION = /\b\d{4}-\d{2}-\d{2}-preview\b|\bapi-version\b/i;
const RE_PRICE = /\$\s?\d|\bNOK\b|\bUSD\b|\bEUR\b|per\s+(million|thousand|1[MK])\s+tokens?|\bpris\w*|\bpricing\b|\bSLA\b|\d+(\.\d+)?\s?%\s*(uptime|oppetid)|\buptime\b/i;

/**
 * Is this text a status/lifecycle/version/price claim?
 * Release-stage, API-version (preview-datoer), and price/SLA are the signals the
 * naive auto-correct mechanism mangled. A bare calendar date is NOT a status
 * claim (only -preview-suffixed versions count) — so dated prose still auto-applies.
 * @param {string} text
 * @returns {{isStatus: boolean, kinds: string[]}}
 */
export function detectStatusClaim(text) {
  const s = String(text ?? '');
  const kinds = [];
  if (RE_GA.test(s) || RE_RELEASE.test(s)) kinds.push('release-stage');
  if (RE_VERSION.test(s)) kinds.push('version');
  if (RE_PRICE.test(s)) kinds.push('price');
  return { isStatus: kinds.length > 0, kinds };
}

function normUrl(u) {
  return String(u).trim().replace(/\/+$/, '').toLowerCase();
}

/**
 * Classify a candidate KB change: may it be auto-applied, or must the operator
 * see it first? Flagged wins — every triggering rule contributes a reason.
 *
 * A change object:
 *   field            — what is changing (label)
 *   old_value        — current KB claim
 *   new_value        — proposed replacement
 *   source_url       — where new_value was fetched from (optional)
 *   authority_source — the designated authority for this claim (optional; null
 *                      today until lag 3 verifisering-INN backfills it)
 *   refutations      — adversarial panel output: [{refuted: boolean, reason?}]
 *                      (LLM runtime; empty here is fine)
 *
 * @param {object} change
 * @returns {{verdict: 'flagged'|'auto-applied', status_claim: boolean, reasons: string[]}}
 */
export function classifyChange(change) {
  const reasons = [];
  const kinds = new Set();
  let statusClaim = false;

  // Rule 1 — STATUS-GATE (spec §21): any status claim in field/old/new → flag, always.
  for (const t of [change.field, change.old_value, change.new_value]) {
    const d = detectStatusClaim(t);
    if (d.isStatus) {
      statusClaim = true;
      d.kinds.forEach((k) => kinds.add(k));
    }
  }
  if (statusClaim) {
    reasons.push(
      `status claim (${[...kinds].join(', ')}) — always operator-gated (spec §21), never auto-applied`,
    );
  }

  // Rule 2 — ADVERSARIAL: the try-to-refute panel found counter-evidence.
  const refs = Array.isArray(change.refutations) ? change.refutations : [];
  const refuted = refs.filter((r) => r && r.refuted === true);
  if (refuted.length > 0) {
    reasons.push(
      `adversarial panel refuted the claim (${refuted.length}) — e.g. ${refuted[0].reason ?? 'no reason given'}`,
    );
  }

  // Rule 3 — AUTHORITY MISMATCH (regression root cause): the new value was
  // anchored on something other than the designated authority. Inert while
  // authority_source is null (pre-lag-3), active once it is backfilled.
  if (
    change.authority_source &&
    change.source_url &&
    normUrl(change.authority_source) !== normUrl(change.source_url)
  ) {
    reasons.push(
      `source is not the designated authority_source — anchored on ${change.source_url} instead of ${change.authority_source}`,
    );
  }

  return {
    verdict: reasons.length ? 'flagged' : 'auto-applied',
    status_claim: statusClaim,
    reasons,
  };
}