import assert from 'node:assert/strict';
import fs from 'node:fs';
import os from 'node:os';
import path from 'node:path';
import test from 'node:test';
import { createSingboxRuntime } from '../../src/server/singboxRuntime.js';

async function waitForStarts(filePath, count) {
  for (let attempt = 0; attempt < 100; attempt += 1) {
    if (fs.existsSync(filePath) && fs.readFileSync(filePath, 'utf8').length >= count) return;
    await new Promise((resolve) => setTimeout(resolve, 10));
  }
  throw new Error(`sing-box did not start ${count} time(s)`);
}

test('dataplane keeps sing-box running when the applied config is unchanged', async (t) => {
  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'harbor-dataplane-'));
  const binDir = path.join(dir, 'bin');
  const configPath = path.join(dir, 'config.json');
  const startsPath = path.join(dir, 'starts');
  fs.mkdirSync(binDir);
  fs.writeFileSync(configPath, '{}');
  fs.writeFileSync(path.join(binDir, 'sing-box'), `#!/usr/bin/env node
if (process.argv[2] === 'check') process.exit(0);
require('node:fs').appendFileSync(process.env.SINGBOX_TEST_STARTS, 'x');
process.on('SIGTERM', () => process.exit(0));
setInterval(() => {}, 60_000);
`);
  fs.chmodSync(path.join(binDir, 'sing-box'), 0o755);

  const previousPath = process.env.PATH;
  process.env.PATH = `${binDir}:${previousPath}`;
  process.env.SINGBOX_TEST_STARTS = startsPath;
  const runtime = createSingboxRuntime({ configPath });
  t.after(async () => {
    await runtime.stop();
    process.env.PATH = previousPath;
    delete process.env.SINGBOX_TEST_STARTS;
    fs.rmSync(dir, { recursive: true, force: true });
  });

  await runtime.apply();
  await waitForStarts(startsPath, 1);
  await runtime.apply();
  assert.equal(fs.readFileSync(startsPath, 'utf8'), 'x');

  fs.writeFileSync(configPath, '{"changed":true}');
  await runtime.apply();
  await waitForStarts(startsPath, 2);
  assert.equal(fs.readFileSync(startsPath, 'utf8'), 'xx');
});