import { readFileSync, existsSync } from 'node:fs';
import { resolve, dirname, relative, extname } from 'node:path';

// Inspect only the graph reached from index.html; old chunks left in dist do not count.
export function verifyTokenBuild(directory) {
  const root = resolve(directory);
  const visited = new Set();
  function visit(path) {
    path = resolve(path);
    const rel = relative(root, path);
    if (rel.startsWith('..') || !existsSync(path) || visited.has(path)) return;
    visited.add(path);
    const text = readFileSync(path, 'utf8');
    for (const match of text.matchAll(/["'`]((?:\.{0,2}\/)?[\w./-]+\.js)["'`]/g)) {
      const ref = match[1];
      visit(ref.startsWith('/') ? resolve(root, ref.slice(1)) : resolve(dirname(path), ref));
    }
  }
  visit(resolve(root, 'index.html'));
  const stats = [...visited].filter((path) => /[\\/]call-stats-[^\\/]+\.js$/.test(path));
  if (stats.length !== 1 || !readFileSync(stats[0], 'utf8').includes('ModelUsageStats-')) {
    throw new Error('The active call statistics page does not include Token usage. Refusing this build.');
  }
  const usage = [...visited].filter((path) => /[\\/]ModelUsageStats-[^\\/]+\.js$/.test(path));
  const hasApi = [...visited].some((path) => extname(path) === '.js' && readFileSync(path, 'utf8').includes('/stats/model-usage/log'));
  if (!usage.length || !hasApi) throw new Error('The active Token component or usage API is missing.');
  return { page: relative(root, stats[0]), component: relative(root, usage[0]), assets: visited.size };
}

console.log(JSON.stringify(verifyTokenBuild(process.argv[2] || 'dist')));