import assert from 'node:assert/strict';
import { spawn } from 'node:child_process';
import { networkInterfaces } from 'node:os';
import test from 'node:test';

function firstExternalIpv4() {
  for (const addresses of Object.values(networkInterfaces())) {
    for (const address of addresses ?? []) {
      if (address.family === 'IPv4' && !address.internal) return address.address;
    }
  }
  throw new Error('No external IPv4 address is available for the binding test');
}

async function waitForResponse(url, child) {
  const deadline = Date.now() + 15_000;
  let lastError;

  while (Date.now() < deadline) {
    if (child.exitCode !== null) {
      throw new Error(`Server exited before becoming reachable (code ${child.exitCode})`);
    }

    try {
      return await fetch(url);
    } catch (error) {
      lastError = error;
      await new Promise((resolve) => setTimeout(resolve, 100));
    }
  }

  throw lastError ?? new Error('Server did not become reachable');
}

test('serves the Space app through a non-loopback container interface', async (t) => {
  const port = 20_000 + Math.floor(Math.random() * 20_000);
  const child = spawn(process.execPath, ['server.js'], {
    cwd: new URL('..', import.meta.url),
    env: { ...process.env, PORT: String(port) },
    stdio: 'ignore',
  });

  t.after(() => child.kill());

  const response = await waitForResponse(`http://${firstExternalIpv4()}:${port}/`, child);
  assert.equal(response.status, 200);
});