import { gzipSync } from 'node:zlib';
import { readdirSync, readFileSync } from 'node:fs';
import { basename, resolve } from 'node:path';

const root = resolve(import.meta.dirname, '../..');
const dist = resolve(root, 'dist');
const html = readFileSync(resolve(dist, 'index.html'), 'utf8');
const entryMatch = html.match(/<script[^>]+src="([^"]+\.js)"/);
if (!entryMatch) throw new Error('Unable to locate the Vite entry script in dist/index.html');

const assets = resolve(dist, 'assets');
const files = readdirSync(assets).filter((file) => file.endsWith('.js'));
const sizes = files.map((file) => ({ file, gzip: gzipSync(readFileSync(resolve(assets, file))).length }));
const entryName = basename(entryMatch[1]);
const entry = sizes.find((item) => item.file === entryName);
if (!entry) throw new Error(`Entry asset ${entryName} was not found`);

const entryBudget = Number(process.env.BUNDLE_ENTRY_GZIP_BUDGET ?? 250 * 1024);
// ECharts core + the three chart types used by the platform currently settle at ~182 KiB.
// Keep a narrow calibrated ceiling so future chart imports cannot silently restore the full bundle.
const chunkBudget = Number(process.env.BUNDLE_CHUNK_GZIP_BUDGET ?? 190 * 1024);
const oversized = sizes.filter((item) => item.file !== entryName && item.gzip > chunkBudget);
console.log(`entry ${entry.file}: ${(entry.gzip / 1024).toFixed(2)} KiB gzip (budget ${(entryBudget / 1024).toFixed(0)} KiB)`);
for (const item of sizes.toSorted((a, b) => b.gzip - a.gzip).slice(0, 10)) {
  console.log(`${item.file}: ${(item.gzip / 1024).toFixed(2)} KiB gzip`);
}
if (entry.gzip > entryBudget || oversized.length) {
  if (oversized.length) console.error(`Oversized async chunks: ${oversized.map((item) => item.file).join(', ')}`);
  process.exit(1);
}