import app from './app';
import http from 'http';
import stoppable  from 'stoppable';
import { logServer } from './lib/logger';

/**
* Normalize a port into a number, string, or false.
*/
const normalizePort = (val:string):string|number|boolean => {
  const port = parseInt(val, 10);

  if (isNaN(port)) {
    // named pipe
    return val;
  }

  if (port >= 0) {
    // port number
    return port;
  }

  return false;
};

/**
* Event listener for HTTP server "error" event.
*/
const onError = (error:any):void => {
  if (error.syscall !== 'listen') {
    throw error;
  }

  const bind = typeof port === 'string'
    ? 'Pipe ' + port
    : 'Port ' + port;

  // handle specific listen errors with friendly messages
  switch (error.code) {
    case 'EACCES':
      console.error(bind + ' requires elevated privileges');
      process.exit(1);
      break;
    case 'EADDRINUSE':
      console.error(bind + ' is already in use');
      process.exit(1);
      break;
    default:
      throw error;
  }
};

/**
* Event listener for HTTP server "listening" event.
*/
const onListening = ():void => {
  const addr = server.address();
  const bind = typeof addr === 'string'
    ? 'pipe ' + addr
    : 'port ' + addr?.port;
  logServer(`server is running at ${bind}`);
};

/**
* Get port from environment and store in Express.
*/
const port:number|string|boolean = normalizePort(process.env.PORT || '3000');

/**
* How long should stoppable wait before it starts force-closing connections
* @description wait max 10 seconds - needs to be shorter than `healthcheck.timeout` (=15sec)
*/
const FORCE_STOP_TIMEOUT = 10000;

/**
* Create HTTP server.
*/
const server = stoppable( http.createServer(app), FORCE_STOP_TIMEOUT );

// Listen on provided port, on all network interfaces.
server.listen(port);
server.on('error', onError);
server.on('listening', onListening);

// quit on ctrl-c when running docker in terminal
// (signal neće biti registriran ako je server pokrenuti via `npm` ili `nodemon` - mora biti pokrenuti izravno via Node)
process.on('SIGINT', () => {
    logServer('got SIGINT (aka ctrl-c in docker). Graceful shutdown ', new Date().toISOString());
    shutdown();
});

// quit properly on docker stop
// (signal neće biti registriran ako je server pokrenuti via `npm` ili `nodemon` - mora biti pokrenuti izravno via Node)
process.on('SIGTERM', () => {
    logServer('got SIGTERM (docker container stop). Graceful shutdown ', new Date().toISOString());
    shutdown();
});

// shut down server
const shutdown = () => {
  // NOTE: server.close is for express based apps
  // If using hapi, use `server.stop`
  server.close((err) => {
    if (err) {
      console.error(err);
      process.exitCode = 1;
    } else {
      logServer('Exiting server process...');
    }
    process.exit();
  });
};