/* global $iq, Strophe */

import { getLogger } from 'jitsi-meet-logger';
const logger = getLogger(__filename);
import ConnectionPlugin from './ConnectionPlugin';
import GlobalOnErrorHandler from '../util/GlobalOnErrorHandler';

/**
 * Ping every 10 sec
 */
const PING_INTERVAL = 10000;

/**
 * Ping timeout error after 15 sec of waiting.
 */
const PING_TIMEOUT = 15000;

/**
 * Will close the connection after 3 consecutive ping errors.
 */
const PING_THRESHOLD = 3;

/**
 * XEP-0199 ping plugin.
 *
 * Registers "urn:xmpp:ping" namespace under Strophe.NS.PING.
 */
class PingConnectionPlugin extends ConnectionPlugin {
    /**
     * Contructs new object
     * @param {XMPP} xmpp the xmpp module.
     * @constructor
     */
    constructor(xmpp) {
        super();
        this.failedPings = 0;
        this.xmpp = xmpp;
    }

    /**
     * Initializes the plugin. Method called by Strophe.
     * @param connection Strophe connection instance.
     */
    init(connection) {
        super.init(connection);
        Strophe.addNamespace('PING', 'urn:xmpp:ping');
    }

    /**
     * Sends "ping" to given <tt>jid</tt>
     * @param jid the JID to which ping request will be sent.
     * @param success callback called on success.
     * @param error callback called on error.
     * @param timeout ms how long are we going to wait for the response. On
     *        timeout <tt>error<//t> callback is called with undefined error
     *        argument.
     */
    ping(jid, success, error, timeout) {
        const iq = $iq({type: 'get', to: jid});
        iq.c('ping', {xmlns: Strophe.NS.PING});
        this.connection.sendIQ(iq, success, error, timeout);
    }

    /**
     * Checks if given <tt>jid</tt> has XEP-0199 ping support.
     * @param jid the JID to be checked for ping support.
     * @param callback function with boolean argument which will be
     * <tt>true</tt> if XEP-0199 ping is supported by given <tt>jid</tt>
     */
    hasPingSupport(jid, callback) {
        this.xmpp.caps.getFeatures(jid).then(features =>
            callback(features.has('urn:xmpp:ping')), error => {
            const errmsg = 'Ping feature discovery error';
            GlobalOnErrorHandler.callErrorHandler(new Error(
                errmsg + ': ' + error));
            logger.error(errmsg, error);
            callback(false);
        });
    }

    /**
     * Starts to send ping in given interval to specified remote JID.
     * This plugin supports only one such task and <tt>stopInterval</tt>
     * must be called before starting a new one.
     * @param remoteJid remote JID to which ping requests will be sent to.
     * @param interval task interval in ms.
     */
    startInterval(remoteJid, interval = PING_INTERVAL) {
        if (this.intervalId) {
            const errmsg = 'Ping task scheduled already';
            GlobalOnErrorHandler.callErrorHandler(new Error(errmsg));
            logger.error(errmsg);
            return;
        }
        this.intervalId = window.setInterval(() => {
            this.ping(remoteJid, () => {
                this.failedPings = 0;
            }, error => {
                this.failedPings += 1;
                const errmsg = 'Ping ' + (error ? 'error' : 'timeout');
                if (this.failedPings >= PING_THRESHOLD) {
                    GlobalOnErrorHandler.callErrorHandler(new Error(errmsg));
                    logger.error(errmsg, error);
                    // FIXME it doesn't help to disconnect when 3rd PING
                    // times out, it only stops Strophe from retrying.
                    // Not really sure what's the right thing to do in that
                    // situation, but just closing the connection makes no
                    // sense.
                    // self.connection.disconnect();
                } else {
                    logger.warn(errmsg, error);
                }
            }, PING_TIMEOUT);
        }, interval);
        logger.info('XMPP pings will be sent every ' + interval + ' ms');
    }

    /**
     * Stops current "ping"  interval task.
     */
    stopInterval() {
        if (this.intervalId) {
            window.clearInterval(this.intervalId);
            this.intervalId = null;
            this.failedPings = 0;
            logger.info('Ping interval cleared');
        }
    }
}

export default function(xmpp) {
    Strophe.addConnectionPlugin('ping', new PingConnectionPlugin(xmpp));
}