import { Log, logger } from '@spine/logger';
import { Server } from 'http';

export class ListenerManager {
  name: string;
  lastConnectionKey: number;
  connectionMap: any;
  listener: Server;
  log: Log;
  constructor(listener: Server, name?: string, log?: Log) {
    this.name = name != null ? name : 'listener';
    this.lastConnectionKey = 0;
    this.connectionMap = {};
    this.listener = listener;
    this.log = log != null ? log : logger(this.name);

    // Track all connections to our server so that we can close them when needed.
    this.listener.on('connection', (connection) => {
      // Increment the connection key.
      this.lastConnectionKey += 1;
      // Generate a new key to represent the connection
      const connectionKey = this.lastConnectionKey;
      // Add the connection to our map.
      this.connectionMap[connectionKey] = connection;
      // Remove the connection from our map when it closes.
      connection.on('close', () => {
        delete this.connectionMap[connectionKey];
      });
    });
  }

  killAllConnections() {
    Object.keys(this.connectionMap).forEach((connectionKey) => {
      this.connectionMap[connectionKey].destroy();
    });
  }

  dispose() {
    return new Promise((resolve) => {
      if (this.listener !== undefined) {
        this.killAllConnections();
        this.log(
          'info',
          'Destroyed all existing connections.',
        );

        this.listener.close(() => {
          this.log(
            'info',
            'Closed listener.',
          );

          resolve();
        });
      } else {
        resolve();
      }
    });
  }
}