#!/usr/bin/env node

const fs = require('node:fs');
const path = require('node:path');
const { spawnSync } = require('node:child_process');

const rootDir = path.resolve(__dirname, '..');
const candidateRoots = ['tests/unit', 'tests/integration', 'tests/npm'];
// Add a `.ts` test to `slowTests` when ANY of these apply:
//   1. It spawns a child process (CLI, bun test, node, gh, etc.).
//   2. It binds a port, starts a server, or talks to localhost.
//   3. It reads a real file from `dist/` or the repo root at runtime.
//   4. It waits on a timer > 500ms or a filesystem watcher.
//   5. A single run consistently takes > 1500ms on reference hardware.
// Tests that literally reference `dist/` in source are auto-forced slow by
// `readsBuiltDist`. This list is the manual catch-all for `.ts` tests that
// meet the criteria above without the literal `dist/` string.
// `tests/unit/scripts/run-test-bucket.test.js` verifies every path here exists
// (catches deletion drift) but CANNOT detect new undeclared slow tests.
// Automated perf-budget enforcement tracked in issue #1071.
const slowTests = [
  'tests/integration/cursor-daemon-lifecycle.test.ts',
  'tests/integration/proxy/daemon-lifecycle.test.ts',
  'tests/unit/commands/persist-command-handler.test.ts',
  'tests/unit/hooks/browser-mcp-advanced-interactions.test.ts',
  'tests/unit/hooks/browser-mcp-downloads-and-files.test.ts',
  'tests/unit/hooks/browser-mcp-navigation-and-query.test.ts',
  'tests/unit/hooks/browser-mcp-orchestration-and-artifacts.test.ts',
  'tests/unit/hooks/browser-mcp-recording-and-replay.test.ts',
  'tests/unit/hooks/browser-mcp-session-and-intercepts.test.ts',
  'tests/unit/targets/codex-runtime-integration.test.ts',
  'tests/unit/targets/codex-settings-bridge-launch.test.ts',
  'tests/unit/targets/droid-command-routing-integration.test.ts',
  'tests/unit/targets/droid-config-manager.test.ts',
  'tests/unit/targets/settings-profile-browser-launch.test.ts',
  'tests/unit/targets/settings-profile-image-analysis-launch.test.ts',
  'tests/unit/targets/settings-profile-websearch-launch.test.ts',
  'tests/unit/web-server/cursor-routes.test.ts',
  'tests/unit/web-server/websearch-routes.test.ts',
];
// CommonJS-heavy JS suites stay slow by default because many of them mutate
// module cache or process state. Opt them into `test:fast` only after they are
// proven stable in the mixed fast bucket.
const fastJsTests = new Set([
  'tests/unit/flag-parsing-simple.test.js',
]);

const filePattern = /(\.test\.(c|m)?[jt]s|\.spec\.(c|m)?[jt]s|-test\.(c|m)?[jt]s)$/;

function collectFiles(dir, files = []) {
  for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
    const fullPath = path.join(dir, entry.name);
    if (entry.isDirectory()) {
      collectFiles(fullPath, files);
      continue;
    }

    if (filePattern.test(entry.name)) {
      files.push(path.relative(rootDir, fullPath).split(path.sep).join('/'));
    }
  }

  return files;
}

function readsBuiltDist(relativePath) {
  const source = fs.readFileSync(path.join(rootDir, relativePath), 'utf8');
  return source.includes('dist/');
}

function getDiscoveredTests() {
  return candidateRoots
    .flatMap((relativeDir) => collectFiles(path.join(rootDir, relativeDir)))
    .sort();
}

function shouldForceSlow(file) {
  if (file.startsWith('tests/npm/')) {
    return true;
  }

  if (/\.(c|m)?js$/.test(file) && !fastJsTests.has(file)) {
    return true;
  }

  return readsBuiltDist(file);
}

function getSlowSet() {
  const discovered = getDiscoveredTests();
  const forceSlow = discovered.filter((file) => shouldForceSlow(file));
  return new Set([...slowTests, ...forceSlow]);
}

function selectBucket(name) {
  const discovered = getDiscoveredTests();
  const slowSet = getSlowSet();

  return name === 'slow'
    ? [...slowSet].sort()
    : discovered.filter((file) => !slowSet.has(file));
}

function ensureBuildForSlowBucket() {
  if (fs.existsSync(path.join(rootDir, 'dist', 'ccs.js'))) {
    return 0;
  }

  const build = spawnSync('bun', ['run', 'build'], {
    cwd: rootDir,
    stdio: 'inherit',
    shell: process.platform === 'win32',
  });

  return build.status ?? 1;
}

function runBucket(name) {
  const selected = selectBucket(name);

  if (selected.length === 0) {
    console.error(`[X] No tests matched the '${name}' bucket.`);
    return 1;
  }

  if (name === 'slow') {
    const buildStatus = ensureBuildForSlowBucket();
    if (buildStatus !== 0) {
      return buildStatus;
    }
  }

  // Slow bucket forces sequential execution because it spawns subprocesses,
  // binds ports, and touches shared state — parallelism causes flakes.
  // Fast bucket keeps bun's default parallelism for speed.
  const bunArgs = name === 'slow'
    ? ['test', '--max-concurrency=1', ...selected]
    : ['test', ...selected];

  const result = spawnSync('bun', bunArgs, {
    cwd: rootDir,
    stdio: 'inherit',
    shell: process.platform === 'win32',
  });

  return result.status ?? 1;
}

function main(args = process.argv.slice(2)) {
  const bucket = args[0];

  if (!['fast', 'slow', 'all'].includes(bucket)) {
    console.error('[X] Usage: node scripts/run-test-bucket.js <fast|slow|all>');
    return 1;
  }

  if (bucket === 'all') {
    let exitCode = 0;

    for (const name of ['fast', 'slow']) {
      const status = runBucket(name);
      if (status !== 0) {
        exitCode = status;
      }
    }

    return exitCode;
  }

  return runBucket(bucket);
}

if (require.main === module) {
  process.exit(main());
}

module.exports = {
  slowTests,
  fastJsTests,
  readsBuiltDist,
  shouldForceSlow,
  getDiscoveredTests,
  getSlowSet,
  selectBucket,
  main,
};