tells.js

/**
 * Tells
 * Pokemon Showdown - http://pokemonshowdown.com/
 *
 * Tells are the offline messaging system for PS. They are received when a
 * user successfully connects under a name that has tells waiting, and are
 * sent when a pm is sent to a user who does not exist or is not online.
 *
 * Tells are cleared after they have existed for a certain length of time
 * in order to remove any inactive messages. This length of time can be
 * specified in config.js
 *
 * @license MIT license
 */

// jscs:disable
var fs = require('fs');
var color = require('./infinite/color');

var tells = {inbox: {}, outbox: {}};
try {
    tells = JSON.parse(fs.readFileSync('config/tells.json'));
} catch (e) {} // file doesn't exist (yet)

/**
 * Purge expired messages from those stored
 * @param threshold The age limit of an "old" tell, in ms
 */
var pruneOld = exports.pruneOld = function (threshold) {
    var now = Date.now();
    var receivers = Object.keys(Tells.inbox);
    for (var i = 0; i < receivers.length; i++) {
        for (var n = 0; n < Tells.inbox[receivers[i]].length; n++) {
            if ((now - Tells.inbox[receivers[i]][n].time) >= threshold) {
                var ips = Object.keys(Tells.inbox[receivers[i]][n].ips);
                for (var ip = 0; ip < ips.length; ip++) {
                    if (Tells.outbox[ips[ip]]) Tells.outbox[ips[ip]]--;
                    if (Tells.outbox[ips[ip]] <= 0) delete Tells.outbox[ips[ip]];
                }
                Tells.inbox[receivers[i]].splice(n, 1);
                n--;
            }
        }
        if (!Tells.inbox[receivers[i]].length) delete Tells.inbox[receivers[i]];
    }
    Tells.writeTells();
};

exports.inbox = tells.inbox || {};
exports.outbox = tells.outbox || {};

/**
 * Write the inbox and outbox to file
 */
exports.writeTells = (function () {
    var writing = false;
    var writePending = false; // whether or not a new write is pending
    var finishWriting = function () {
        writing = false;
        if (writePending) {
            writePending = false;
            Tells.writeTells();
        }
    };
    return function () {
        if (writing) {
            writePending = true;
            return;
        }
        writing = true;
        var data = JSON.stringify({inbox: Tells.inbox, outbox: Tells.outbox});
        fs.writeFile('config/tells.json.0', data, function () {
            // rename is atomic on POSIX, but will throw an error on Windows
            fs.rename('config/tells.json.0', 'config/tells.json', function (err) {
                if (err) {
                    // This should only happen on Windows.
                    fs.writeFile('config/tells.json', data, finishWriting);
                    return;
                }
                finishWriting();
            });
        });
    };
})();

/**
 * Format a user's inbox and send it on to the client to be delivered
 * @param userid    The userid whose tells to send
 * @param user      The User object to send the tells to
 */
exports.sendTell = function (userid, user) {
    var buffer = '|raw|';
    var tellsToSend = Tells.inbox[userid];
    for (var i = 0; i < tellsToSend.length; i++) {
        var ips = Object.keys(tellsToSend[i].ips);
        for (var ip = 0; ip < ips.length; ip++) {
            if (Tells.outbox[ips[ip]]) Tells.outbox[ips[ip]]--;
            if (Tells.outbox[ips[ip]] <= 0) delete Tells.outbox[ips[ip]];
        }
        var timeStr = Tells.getTellTime(tellsToSend[i].time);
        buffer += '<div class="chat"><font color="gray">[' + timeStr + ' ago]</font> <b><font color="' + color(toId(tellsToSend[i].sender)) + '">' + tellsToSend[i].sender + ':</font></b> ' + Tools.escapeHTML(tellsToSend[i].msg.replace(/\|/g, '&#124;')) + '</div>';
    }
    user.send(buffer);
    delete Tells.inbox[userid];
    Tells.writeTells();
};

/**
 * Store a tell to be received later
 * @param sender    The User object of the sender
 * @param receiver  The target userid
 * @param msg       The message to be send
 * @return      false if the receiver has a full inbox
 *          null if the sender has a full outbox
 *          otherwise true
 */
exports.addTell = function (sender, receiver, msg) {
    if (Tells.inbox[receiver] && Tells.inbox[receiver].length >= 5) return false;
    var ips = Object.keys(sender.ips);
    for (var i = 0; i < ips.length; i++) {
        if (!Tells.outbox[ips[i]]) {
            Tells.outbox[ips[i]] = 1;
        } else {
            if (Tells.outbox[ips[i]] >= 10) return null;
            Tells.outbox[ips[i]]++;
        }
    }
    if (!Tells.inbox[receiver]) Tells.inbox[receiver] = [];
    var newTell = {
        'sender': sender.name,
        time: Date.now(),
        'msg': msg,
        ips: sender.ips
    };
    Tells.inbox[receiver].push(newTell);
    Tells.writeTells();
    return true;
};

/**
 * Converts a UNIX timestamp into 'x minutes, y seconds ago' form
 * @param time  UNIX timestamp (e.g., 1405460769855)
 * @return  A human readable time difference between now and the given time
 */
exports.getTellTime = function (time) {
    time = Date.now() - time;
    time = Math.round(time / 1000); // rounds to nearest second
    var seconds = time % 60;
    var times = [];
    if (seconds) times.push(String(seconds) + (seconds === 1 ? ' second' : ' seconds'));
    var minutes, hours, days;
    if (time >= 60) {
        time = (time - seconds) / 60; // converts to minutes
        minutes = time % 60;
        if (minutes) times.unshift(String(minutes) + (minutes === 1 ? ' minute' : ' minutes'));
        if (time >= 60) {
            time = (time - minutes) / 60; // converts to hours
            hours = time % 24;
            if (hours) times.unshift(String(hours) + (hours === 1 ? ' hour' : ' hours'));
            if (time >= 24) {
                days = (time - hours) / 24; // you can probably guess this one
                if (days) times.unshift(String(days) + (days === 1 ? ' day' : ' days'));
            }
        }
    }
    if (!times.length) times.push('0 seconds');
    return times.join(', ');
};

// clear old messages every two hours
exports.pruneOldTimer = setInterval(pruneOld, 1000 * 60 * 60 * 2,
        Config.tellsexpiryage || 1000 * 60 * 60 * 24 * 7);