import rimraf from 'rimraf';
import { v4 as uuidV4 } from 'uuid';
import path from 'path';
import os from 'os';
import fs from 'fs';
import B from 'bluebird';

const commands = {};
const rimrafAsync = B.promisify(rimraf);
const readFileAsync = B.promisify(fs.readFile);

/**
 * Gets base64 screenshot for device
 * It is required that Simulator is in _booted_ state.
 *
 * @since Xcode SDK 8.1
 * @return {string} Base64-encoded Simulator screenshot.
 * @throws {Error} If the corresponding simctl subcommand command
 *                 returns non-zero return code.
 * @throws {Error} If the `udid` instance property is unset
 */
commands.getScreenshot = async function getScreenshot () {
  const udid = this.requireUdid('io screenshot');
  const pathToScreenshotPng = path.resolve(os.tmpdir(), `${uuidV4()}.png`);
  try {
    await this.exec('io', {
      args: [udid, 'screenshot', pathToScreenshotPng],
    });
    return (await readFileAsync(pathToScreenshotPng)).toString('base64');
  } finally {
    await rimrafAsync(pathToScreenshotPng);
  }
};

export default commands;