import assert from 'node:assert/strict';
import test from 'node:test';
import { readFileSync } from 'node:fs';
import { gunzipSync } from 'node:zlib';
import { createServer } from 'node:http';
import { once } from 'node:events';
import { buildingCompressionMiddleware } from '../scripts/building-compression.ts';

test('building transfer uses lossless gzip with automatic client decoding and identity fallback', async () => {
  const raw = readFileSync(new URL('../public/buildings/gwacheon.baked.bin', import.meta.url));
  const gzip = readFileSync(new URL('../public/buildings/gwacheon.baked.bin.gz', import.meta.url));
  assert.deepEqual(gunzipSync(gzip), raw);
  assert.ok(gzip.length < raw.length * 0.3);
  const middleware = buildingCompressionMiddleware(new URL('../public/', import.meta.url));
  const server = createServer((req, res) => middleware(req, res, () => {
    res.setHeader('Content-Length', raw.length);
    res.end(req.method === 'HEAD' ? undefined : raw);
  }));
  server.listen(0, '127.0.0.1');
  await once(server, 'listening');
  const url = `http://127.0.0.1:${(server.address() as {port: number}).port}/buildings/gwacheon.baked.bin?v=test`;
  try {
    const response = await fetch(url, { headers: { 'Accept-Encoding': 'gzip' } });
    assert.equal(response.headers.get('content-encoding'), 'gzip');
    assert.equal(Number(response.headers.get('content-length')), gzip.length);
    assert.match(response.headers.get('vary')!, /Accept-Encoding/i);
    assert.deepEqual(Buffer.from(await response.arrayBuffer()), raw);
    const head = await fetch(url, { method: 'HEAD', headers: { 'Accept-Encoding': 'gzip' } });
    assert.equal(head.headers.get('content-encoding'), 'gzip');
    assert.equal((await head.arrayBuffer()).byteLength, 0);
    for (const encoding of ['identity', 'gzip;q=0', '*;q=1, gzip;q=0']) {
      const plain = await fetch(url, { headers: { 'Accept-Encoding': encoding } });
      assert.equal(plain.headers.get('content-encoding'), null);
      assert.deepEqual(Buffer.from(await plain.arrayBuffer()), raw);
    }
  } finally { server.closeAllConnections(); await new Promise<void>(resolve => server.close(() => resolve())); }
});