/**
 * Minimal test runner — describe/it with timing and summary.
 * No external dependencies. Import this from test files.
 */

const suites = [];
let currentSuite = null;
let totalTests = 0;
let totalPassed = 0;
let totalFailed = 0;
const failures = [];

export function describe(name, fn) {
  currentSuite = { name, tests: [], passed: 0, failed: 0, duration: 0 };
  suites.push(currentSuite);
  fn();
  currentSuite = null;
}

export function it(name, fn) {
  if (!currentSuite) {
    throw new Error(`it() called outside describe(). Test: "${name}"`);
  }
  currentSuite.tests.push({ name, fn, async: typeof fn === 'function' });
}

// Run all suites and print results
export async function run() {
  let globalStart = Date.now();

  for (const suite of suites) {
    const suiteStart = Date.now();
    process.stdout.write(`\n${suite.name}\n${'─'.repeat(suite.name.length + 2)}\n`);

    for (const test of suite.tests) {
      totalTests++;
      const testStart = Date.now();
      try {
        const result = test.fn();
        if (result instanceof Promise) {
          await result;
        }
        const ms = Date.now() - testStart;
        totalPassed++;
        suite.passed++;
        process.stdout.write(`  ✓ ${test.name} (${ms}ms)\n`);
      } catch (err) {
        const ms = Date.now() - testStart;
        totalFailed++;
        suite.failed++;
        failures.push({ suite: suite.name, test: test.name, error: err.message, stack: err.stack });
        process.stdout.write(`  ✗ ${test.name} (${ms}ms)\n`);
        process.stdout.write(`    → ${err.message}\n`);
      }
    }

    suite.duration = Date.now() - suiteStart;
  }

  const totalMs = Date.now() - globalStart;

  process.stdout.write(`\n${'='.repeat(60)}\n`);
  process.stdout.write(`Results: ${totalPassed}/${totalTests} passed`);
  if (totalFailed > 0) {
    process.stdout.write(` | ${totalFailed} FAILED`);
  }
  process.stdout.write(` | ${totalMs}ms\n`);
  process.stdout.write(`${'='.repeat(60)}\n`);

  if (failures.length > 0) {
    process.stdout.write(`\nFailures:\n`);
    for (const f of failures) {
      process.stdout.write(`  [${f.suite}] ${f.test}\n`);
      process.stdout.write(`    Error: ${f.error}\n`);
      process.stdout.write(`    ${f.stack.split('\n')[1].trim()}\n`);
    }
  }

  return { totalTests, totalPassed, totalFailed, totalMs, failures };
}