import * as childProcess from 'child_process';

export function execute(command: string, args: string[], options?: {cwd?: string}): Promise<string> {

  if (process.env.TERM_PROGRAM === 'vscode') {
    throw new Error('running go subprocesses in VS Code seems to be broken!');
    // Namely, it seems that no data is collected from stdout/stderr streams.
    // Even just running `go version > 1.txt` in the terminal produces an empty file.
  }

  const spawnOptions: childProcess.SpawnOptions = {shell: true};
  if (options && options.cwd) {
    spawnOptions.cwd = options.cwd;
  }

  return new Promise((resolve, reject) => {
    let stdout = '';
    let stderr = '';

    const proc = childProcess.spawn(command, args, spawnOptions);
    proc.stdout.on('data', (data: Buffer) => {
      stdout = stdout + data;
    });
    proc.stderr.on('data', (data: Buffer) => {
      stderr = stderr + data;
    });

    proc.on('close', (code) => {
      if (code !== 0) {
        return reject(stdout || stderr);
      }
      resolve(stdout || stderr);
    });
  });
}