import { readdirSync } from 'fs';
import { spawn } from 'child_process';
import path from 'path';

const testsDir = path.resolve('tests');
const files = readdirSync(testsDir)
  .filter(f => f.endsWith('.test.ts'))
  .sort();

const STALL_TIMEOUT = 20_000;   // kill if no output for 20s
const MAX_RETRIES = 3;
// retry logic needed because tests get randomly get stuck on startup with bun
// strace shows bun completely spinning in futex and not doing anything else.
// Only a stall-kill is retried — a genuine assertion failure returns
// {ok: false, stalled: false} and must NOT be retried, or a real product bug
// that fails intermittently would be laundered into a pass.
function runTest(filePath: string): Promise<{ ok: boolean; stalled: boolean }> {
  return new Promise((resolve) => {
    const child = spawn('bun', ['test', '--bail=1', '--timeout', '30000', filePath], {
      stdio: ['ignore', 'pipe', 'pipe'],
    });

    let stalled = false;
    let timer = setTimeout(onStall, STALL_TIMEOUT);

    function onStall() {
      stalled = true;
      console.error(`\n[test-runner] stall detected, killing ${path.basename(filePath)} (no output for ${STALL_TIMEOUT / 1000}s)`);
      child.kill('SIGKILL');
    }

    function resetTimer() {
      clearTimeout(timer);
      timer = setTimeout(onStall, STALL_TIMEOUT);
    }

    child.stdout!.on('data', (chunk: Buffer) => {
      process.stdout.write(chunk);
      resetTimer();
    });
    child.stderr!.on('data', (chunk: Buffer) => {
      process.stderr.write(chunk);
      resetTimer();
    });

    child.on('close', (code) => {
      clearTimeout(timer);
      resolve({ ok: code === 0, stalled });
    });
  });
}

let passed = 0;
let failed = 0;

for (const file of files) {
  const filePath = path.join(testsDir, file);
  let ok = false;

  for (let attempt = 1; attempt <= MAX_RETRIES; attempt++) {
    if (attempt > 1) {
      console.log(`[test-runner] retrying ${file} (attempt ${attempt}/${MAX_RETRIES})`);
    }
    const result = await runTest(filePath);
    ok = result.ok;
    // Retry only the futex stall — a genuine failure is final.
    if (ok || !result.stalled) break;
  }

  if (ok) passed++;
  else failed++;
}

console.log(`\n${passed + failed} test files: ${passed} passed${failed ? `, ${failed} failed` : ''}`);
if (failed > 0) process.exit(1);