#!/usr/bin/env node
const { exec, spawn } = require('child_process');

const ROOT_DIR = __dirname + '/..';

function run(cmd) {
  return new Promise((resolve, reject) => {
    const p = exec(cmd, { cwd: ROOT_DIR, maxBuffer: 1024 * 1024 * 10 });
    p.stdout.pipe(process.stdout);
    p.stderr.pipe(process.stderr);
    p.on('close', code => (code === 0 ? resolve() : reject(new Error(cmd + ' exited with ' + code))));
  });
}

function adbList() {
  return new Promise((resolve, reject) => {
    exec('adb devices -l', (err, stdout) => {
      if (err) return reject(err);
      resolve(stdout);
    });
  });
}

/**
 * Check if Metro is already listening on port 8081.
 */
function isMetroRunning() {
  return new Promise(resolve => {
    exec('lsof -iTCP:8081 -sTCP:LISTEN -t', (err, stdout) => {
      resolve(!err && stdout.trim().length > 0);
    });
  });
}

/**
 * Start Metro bundler in the background. Returns a cleanup function.
 */
function startMetro() {
  console.log('[run-detox] Starting Metro bundler on port 8081...');
  const metro = spawn('npx', ['react-native', 'start', '--port', '8081', '--reset-cache'], {
    cwd: ROOT_DIR,
    stdio: ['ignore', 'pipe', 'pipe'],
    detached: false,
  });
  metro.stdout.on('data', d => process.stdout.write('[metro] ' + d));
  metro.stderr.on('data', d => process.stderr.write('[metro] ' + d));
  metro.on('error', err => console.error('[run-detox] Metro error:', err.message));
  return metro;
}

/**
 * Wait until Metro is ready (listening on 8081), with a timeout.
 */
function waitForMetro(timeoutMs = 60000) {
  return new Promise((resolve, reject) => {
    const start = Date.now();
    const interval = setInterval(() => {
      exec('lsof -iTCP:8081 -sTCP:LISTEN -t', (err, stdout) => {
        if (!err && stdout.trim().length > 0) {
          clearInterval(interval);
          resolve();
        } else if (Date.now() - start > timeoutMs) {
          clearInterval(interval);
          reject(new Error('Timed out waiting for Metro to start on port 8081'));
        }
      });
    }, 2000);
  });
}

(async () => {
  let metroProcess = null;
  try {
    const out = await adbList();
    const lines = out.split('\n').slice(1).map(l => l.trim()).filter(Boolean);
    // filter out emulator entries (emulator-*) and look for 'device' state
    const attached = lines
      .map(l => l.split(/\s+/)[0])
      .filter(id => id && !id.startsWith('emulator-'));

    const useConfig = attached.length > 0 ? 'android.attached+android.debug' : 'android.emu.debug+android.debug';
    console.log('\n[run-detox] Detected attached devices:', attached.join(', ') || '(none)');
    console.log('[run-detox] Using configuration:', useConfig, '\n');

    // Ensure Metro is running (required for debug APK to load the JS bundle)
    const metroAlready = await isMetroRunning();
    if (metroAlready) {
      console.log('[run-detox] Metro is already running on port 8081.');
    } else {
      metroProcess = startMetro();
      console.log('[run-detox] Waiting for Metro to be ready (up to 60s)...');
      await waitForMetro(60000);
      console.log('[run-detox] Metro is ready.\n');
    }

    console.log('Building...');
    await run(`npx detox build -c ${useConfig}`);
    console.log('Running tests...');
    await run(`npx detox test -c ${useConfig}`);
  } catch (err) {
    console.error('\n[run-detox] Error:', err.message || err);
    process.exit(1);
  } finally {
    if (metroProcess) {
      console.log('\n[run-detox] Stopping Metro bundler...');
      metroProcess.kill('SIGTERM');
    }
  }
})();