const childProcess = require('child_process');

function getExecutable(command) {
  return process.platform === 'win32' ? `${command}.cmd` : command;
}

function commandExists(command) {
  const lookupCommand = process.platform === 'win32' ? 'where.exe' : 'which';
  const result = childProcess.spawnSync(lookupCommand, [getExecutable(command)], {
    stdio: 'ignore',
  });
  return result.status === 0;
}

function ensureYarnAvailable(isCommandAvailable = commandExists) {
  if (!isCommandAvailable('yarn')) {
    throw new Error('未检测到 Yarn，请先安装 Yarn');
  }
}

function runYarn(args, cwd) {
  ensureYarnAvailable();
  const executable = getExecutable('yarn');
  console.log(`执行: yarn ${args.join(' ')}`);
  if (process.platform === 'win32') {
    childProcess.execFileSync(process.env.ComSpec || 'cmd.exe', [
      '/d',
      '/s',
      '/c',
      executable,
      ...args,
    ], { cwd, stdio: 'inherit' });
    return;
  }
  childProcess.execFileSync(executable, args, { cwd, stdio: 'inherit' });
}

module.exports = { commandExists, ensureYarnAvailable, runYarn };