// Verdict derivation. Posture: BLOCK on confirmed critical/high findings in
// correctness/security; everything else is warn-or-pass. Human override =
// admin merge (branch protection does not apply to admins).

const BLOCKING_SEVERITIES = new Set(['critical', 'high']);
const BLOCKING_AXES = new Set(['correctness', 'security']);

export function isBlockingFinding(f) {
  if (!f || typeof f !== 'object') return false;
  const sev = String(f.severity || '').toLowerCase();
  const conf = String(f.confidence || '').toLowerCase();
  if (!BLOCKING_SEVERITIES.has(sev)) return false;
  if (conf !== 'confirmed') return false;
  // If the model tagged an axis, only correctness/security block.
  // Untagged critical+confirmed findings block too (conservative).
  const axis = f.axis ? String(f.axis).toLowerCase() : null;
  return axis === null || BLOCKING_AXES.has(axis);
}

export function deriveVerdict(review) {
  const findings = Array.isArray(review?.findings) ? review.findings : [];
  if (findings.some(isBlockingFinding)) return 'fail';
  const hasWarn = findings.some(f => {
    const sev = String(f?.severity || '').toLowerCase();
    return sev === 'critical' || sev === 'high' || sev === 'medium';
  });
  if (hasWarn) return 'warn';
  // trust the model's verdict if it said warn without matching findings
  if (review?.verdict === 'warn') return 'warn';
  return 'pass';
}

export function normalizeReview(raw) {
  if (!raw || typeof raw !== 'object') return null;
  const axesNames = ['correctness', 'security', 'tests_coverage', 'design_simplicity',
    'performance', 'style', 'breaking_changes', 'docs'];
  const axes = {};
  for (const name of axesNames) {
    const a = raw.axes?.[name];
    axes[name] = {
      score: clampScore(a?.score),
      rationale: typeof a?.rationale === 'string' ? a.rationale.slice(0, 500) : ''
    };
  }
  const findings = (Array.isArray(raw.findings) ? raw.findings : []).map(f => ({
    title: String(f?.title ?? 'untitled').slice(0, 200),
    file: String(f?.file ?? '').slice(0, 300),
    line: Number.isFinite(Number(f?.line)) ? Number(f.line) : null,
    severity: pick(String(f?.severity || '').toLowerCase(), ['critical', 'high', 'medium', 'low'], 'low'),
    confidence: pick(String(f?.confidence || '').toLowerCase(), ['confirmed', 'plausible'], 'plausible'),
    axis: f?.axis ? String(f.axis).toLowerCase() : null,
    detail: String(f?.detail ?? '').slice(0, 2000)
  }));
  const review = {
    axes,
    overall: clampScore(raw.overall),
    grade: pick(String(raw.grade || '').toUpperCase(), ['A', 'B', 'C', 'D', 'F'], 'C'),
    findings,
    verdict: pick(String(raw.verdict || '').toLowerCase(), ['pass', 'warn', 'fail'], 'pass')
  };
  review.verdict = deriveVerdict(review); // service-side derivation is authoritative
  return review;
}

function clampScore(v) {
  const n = Number(v);
  if (!Number.isFinite(n)) return 0;
  return Math.max(0, Math.min(100, Math.round(n)));
}

function pick(v, allowed, fallback) {
  return allowed.includes(v) ? v : fallback;
}