import EventEmitter from 'events';
import * as jsforce from 'jsforce';
import * as types from './types';

export default class Salesforce {
  /**
   * SalesForce Connection.
   *
   * @var {Object}
   */
  private connection: any;

  /**
   * The interval ID.
   *
   * @var {Object}
   */
  private intervalID: any;

  /**
   * Plugin handler has started.
   *
   * @var {Boolean}
   */
  private started: boolean = false;

  /**
   * The date of the last query.
   *
   * @var {String}
   */
  private startTime: String = new Date().toISOString()

  /**
   *
   */
  private subscriptions: Array<any> = []

  /**
   * @constructor
   * @param {Object} config
   * @param {EventEmitter} eventEmitter
   */
  constructor(private config: types.Config, private eventEmitter: EventEmitter) {
    this.eventEmitter.emit('info', 'Initializing SalesForce');
  }

  /**
   * Start listening for events.
   */
  start() {
    if (!this.started) {
      const {
        loginurl,
        username,
        password,
        securitytoken,
      } = this.config;

      this.connection = new jsforce.Connection({ loginUrl: loginurl });
      this.eventEmitter.emit('info', 'Connecting to SalesForce...');

      this.connection.login(username, password + securitytoken, (err: string) => {
        if (err) throw new Error(err);

        this.eventEmitter.emit('success', 'Successfully connected to SalesForce!');

        Object.keys(this.config.subscribe).forEach((name: string) => {
          if (this.isSubscribed(name)) {
            const Subscription = require(`./subscriptions/${this.getFormattedSubscriptionName(name)}`);
            const feed = new Subscription.default(this.connection, this.eventEmitter);

            feed.lastQueryTime = this.startTime;

            this.subscriptions.push(feed);
          }
        });

        this.started = true;
        this.intervalID = setInterval(() => this.run(), this.getInterval());
      });
    }
  }

  /**
   * Stop listening for events.
   */
  stop() {
    if (this.started) {
      this.started = false;
      clearInterval(this.intervalID);
    }
  }

  /**
   * Query for the most recent SF login events.
   */
  run() {
    this.subscriptions.forEach(subscription => {
      this.eventEmitter.emit('info', `Querying SalesForce ${subscription.getName()} at ${subscription.lastQueryTime}`);

      subscription.run();
    });
  }

  /**
   * Get the formatted subscription name.
   *
   * @param {string} name
   */
  getFormattedSubscriptionName(name: string): String {
    return name.charAt(0).toUpperCase() + name.slice(1);
  }

  /**
   * Get the interval for requests.
   *
   * @returns {Number}
   */
  getInterval(): number {
    return (this.config.interval || 10) * 1000;
  }

  /**
   * 
   */
  isSubscribed(name: string): boolean {
    return this.config.subscribe[name] === true;
  }
}