import { spawnSync } from 'node:child_process';
import fs from 'node:fs';
import { pathToFileURL } from 'node:url';

export function evaluateAudit(report, lock, now = Date.now()) {
  if (report?.error || !report?.metadata?.vulnerabilities || !report?.vulnerabilities || !lock?.packages) {
    return { accepted: [], failures: ['Missing or invalid audit/lock data'] };
  }
  const accepted = [], failures = [];
  const allowedChain = new Set(['braces', 'micromatch', 'fast-glob', '@next/eslint-plugin-next', 'eslint-config-next']);
  const devOnlyApprovedOrigin = (name, visited = new Set()) => {
    const finding = report.vulnerabilities[name];
    if (!allowedChain.has(name) || visited.has(name) || finding?.severity !== 'high' ||
        !Array.isArray(finding.nodes) || !finding.nodes.length ||
        finding.nodes.some(node => lock.packages[node]?.dev !== true || name === 'braces' && lock.packages[node]?.version !== '3.0.3') ||
        !Array.isArray(finding.via) || !finding.via.length) return false;
    const path = new Set(visited).add(name);
    return finding.via.every(origin => typeof origin === 'string' ? devOnlyApprovedOrigin(origin, path) :
      origin?.name === 'braces' && origin.dependency === 'braces' && origin.severity === 'high' && origin.url === 'https://github.com/advisories/GHSA-vfj7-8cjw-p6xm');
  };
  for (const [name, finding] of Object.entries(report.vulnerabilities)) {
    if (!['info', 'low', 'moderate', 'high', 'critical'].includes(finding.severity)) {
      failures.push(`${name}: invalid severity`);
    } else if (['high', 'critical'].includes(finding.severity)) {
      // Owner-approved on 17 October: no upstream fix; trusted lint patterns only, never production dependencies.
      if (Number.isFinite(now) && now < Date.parse('2026-11-01T00:00:00Z') && devOnlyApprovedOrigin(name)) accepted.push(name);
      else failures.push(`${name}: ${finding.severity}`);
    }
  }
  return { accepted, failures };
}

if (process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href) {
  try {
    const result = spawnSync(process.platform === 'win32' ? 'npm.cmd' : 'npm', ['audit', '--json', '--audit-level=high'], {
      encoding: 'utf8', maxBuffer: 8 * 1024 * 1024, shell: process.platform === 'win32',
    });
    fs.mkdirSync('.artifacts', { recursive: true });
    fs.writeFileSync('.artifacts/frontend-audit.json', result.stdout || '');
    if (result.error || result.signal || ![0, 1].includes(result.status)) throw new Error('npm audit did not complete');
    const report = JSON.parse(result.stdout);
    const decision = evaluateAudit(report, JSON.parse(fs.readFileSync('package-lock.json', 'utf8')));
    console.log(JSON.stringify({ report, ...decision,
      temporaryException: decision.accepted.length ? 'GHSA-vfj7-8cjw-p6xm: dev-only; expires after 2026-10-31 UTC' : null }, null, 2));
    process.exitCode = decision.failures.length ? 1 : 0;
  } catch (error) {
    console.error(error.message);
    process.exitCode = 1;
  }
}