import { Argv, Arguments } from 'yargs';
import { ROOT_CA_CERT_PATH, DEFAULT_REMOTE_PORT } from '../../src/constants';
import * as express from 'express';
import * as https from 'https';
import * as fs from 'fs';

function assertIsPositiveInteger(
  arg: unknown,
  label: string
): asserts arg is number {
  if (typeof arg !== 'number' || (arg !== parseInt('' + arg) && arg <= 0))
    throw new Error(
      `expected ${label} to be a positive integer. Found: ${JSON.stringify(
        arg
      )}`
    );
}

function assertIsString(arg: unknown, label: string): asserts arg is string {
  if (typeof arg !== 'string')
    throw new Error(
      `expected ${label} to be a string. Found: ${JSON.stringify(arg)}`
    );
}

export const command = 'remote';
export const desc = 'Create an empty repo';
export const builder = (yarg: Argv): void => {
  yarg.option('port', {
    describe: 'port number where the remote host should be connected',
    default: DEFAULT_REMOTE_PORT
  });
  yarg.option('cert', {
    describe: 'certificate details',
    required: true
  });
  yarg.option('key', {
    describe: 'private key details',
    required: true
  });
};
export const handler = (argv: Arguments): void => {
  const { port, cert, key } = argv;
  assertIsPositiveInteger(port, 'port');
  assertIsString(cert, 'cert');
  assertIsString(key, 'key');
  const app = express();
  const credentials = {
    key: key.replace(/\\n/g, '\n'),
    cert: cert.replace(/\\n/g, '\n')
  };
  app.get('/get_remote_certificate', (req, res) => {
    if (!fs.existsSync(ROOT_CA_CERT_PATH)) {
      throw new Error(
        `Could not read the public certificate file ${ROOT_CA_CERT_PATH}, please check the file exists and try again.`
      );
    }
    res.send(fs.readFileSync(ROOT_CA_CERT_PATH, 'utf8'));
  });

  const httpsServer = https.createServer(credentials, app);
  const server = httpsServer.listen(port, () =>
    console.log(`Server started at port: ${port}\n
        ---\n
        STATE: READY_FOR_CONNECTION\n
        ---\n`)
  );

  app.get('/close_remote_server', (req, res) => {
    res.send(`Closing remote server`);
    server.close(() => {
      console.log(`Remote server closed successfully\n
          ---\n
          STATE: REMOTE_CONNECTION_CLOSED\n
          ---\n`);
    });
  });
};