/**
 * A [wkhtmltopdf](https://wkhtmltopdf.org) wrapper for AWS Lambda.
 * @param {string} html the html content
 * @param {any} options available at [wkhtmltopdf's website](https://wkhtmltopdf.org/docs.html)
 * @param {string} rootDir rootDir to use instead of the default one to locate `wkhtmltopdf`
 */
export function html2PDF(html: string, options: any, rootDir?: string): Promise<any> {
  if (process && process.env) process.env.PATH = process.env.PATH + ':' + process.env.LAMBDA_TASK_ROOT;
  let exePath = `${rootDir || '.'}/node_modules/aws-wkhtmltopdf/wkhtmltopdf`;
  options = options || [];
  return new Promise((resolve, reject) => {
    let bufs: Array<any> = [];
    var proc = require('child_process').spawn('/bin/sh', [
      '-o',
      'pipefail',
      '-c',
      exePath + ' ' + options.join(' ') + ' - - | cat'
    ]);
    proc
      .on('error', (error: Error) => reject(error))
      .on('exit', (code: string) => {
        if (code) reject(new Error(`Exited with code ${code}`));
        else resolve(Buffer.concat(bufs));
      });
    proc.stdin.end(html);
    proc.stdout.on('data', (data: any) => bufs.push(data)).on('error', (error: Error) => reject(error));
  });
}