twitch-chat/static/main.js

const timeout = 120000;

class Message {
    constructor(object, onDestroy) {
        this.target = object.target;
        this.context = object.context;
        this.message = object.message;
        this.self = object.self;
    }

    createEl() {
        this.element = document.createElement('li');
        this.element.className = "item";
        this.element.style.position = "relative";

        let badges = document.createElement('span');
        badges.className = 'badges';
        for (let key in this.context.badges) {
            let badge = document.createElement('span');
            badge.className = "badge";
            badge.innerHTML = '<img src="/static/' + key + '.png">';
            badges.appendChild(badge);
        }

        let name = document.createElement('span');
        name.className = "text name";
        name.style.color = readableColor(this.context.color);
        name.innerHTML = escapeHtml(this.context["display-name"]);
        badges.appendChild(name);

        this.element.appendChild(badges);

        let messageSpan = document.createElement('span');
        let {message, emotes} = fixEmotes(this.message, this.context.emotes);
        let text = formatEmotes(message, emotes);
        text = replaceAll(text, "DragonRck", '<img class="emoticon" src="/static/dragonrck.png">');
        messageSpan.innerHTML = text;
        messageSpan.className = "text message";
        this.element.appendChild(messageSpan);

        setTimeout(() => this.destroy(), timeout);
        return this.element;
    }

    destroy() {
        this.element.className += ' destroy';
    }
}

function escapeHtml(unsafe) {
    return unsafe
        .replace(/&/g, "&amp;")
        .replace(/</g, "&lt;")
        .replace(/>/g, "&gt;")
        .replace(/"/g, "&quot;")
        .replace(/'/g, "&#039;");
}

function fixEmotes(message, emotes) {
    let offsets = [[0, 0]];

    let len = message.length;
    let newMessage = '';


    let currentCharIndex = 0;
    let currentOffset = 0;
    while (currentCharIndex < len) {
        let character = message.charAt(currentCharIndex);
        switch (character) {
            case '&':
                newMessage += '&amp;';
                currentOffset += 4;
                offsets.push([currentCharIndex, currentOffset]);
                break;
            case '<':
                newMessage += '&lt;';
                currentOffset += 3;
                offsets.push([currentCharIndex, currentOffset]);
                break;
            case '>':
                newMessage += '&gt;';
                currentOffset += 3;
                offsets.push([currentCharIndex, currentOffset]);
                break;
            case '"':
                newMessage += '&quot;';
                currentOffset += 5;
                offsets.push([currentCharIndex, currentOffset]);
                break;
            case "'":
                newMessage += '&#039;';
                currentOffset += 5;
                offsets.push([currentCharIndex, currentOffset]);
                break;
            default:
                newMessage += character;
        }

        currentCharIndex++;
    }

    for (let emoteType in emotes) {
        let emoteSet = emotes[emoteType];
        for (let emoteKey in emoteSet) {
            let boundaries = emoteSet[emoteKey].split('-').map(x => parseInt(x, 10));

            for (let i = 0; i < 2; i++) {
                // Find floor entry

                let entryIndex = 0;
                while (entryIndex + 1 < offsets.length && offsets[entryIndex + 1][0] < boundaries[i]) {
                    entryIndex++;
                }

                boundaries[i] += offsets[entryIndex][1];

            }

            emoteSet[emoteKey] = boundaries.map(x => x + "").join('-');

        }
    }

    return {message: newMessage, emotes};


}

function formatEmotes(text, emotes) {
    var splitText = text.split('');
    for(var i in emotes) {
        var e = emotes[i];
        for(var j in e) {
            var mote = e[j];
            if(typeof mote == 'string') {
                mote = mote.split('-');
                mote = [parseInt(mote[0]), parseInt(mote[1])];
                var length =  mote[1] - mote[0],
                    empty = Array.apply(null, new Array(length + 1)).map(function() { return '' });
                splitText = splitText.slice(0, mote[0]).concat(empty).concat(splitText.slice(mote[1] + 1, splitText.length));
                splitText.splice(mote[0], 1, '<img class="emoticon" src="http://static-cdn.jtvnw.net/emoticons/v1/' + i + '/4.0">');
            }
        }
    }
    return splitText.join('');
}

function readableColor(color) {
    switch (color.toLowerCase()) {
        case "#0000ff": return "#8b58ff";
        case "#008000": return "#319a24";
        case "#b22222": return "#db4a3f";
        default: return color;
    }
}

function replaceAll(input, from, to) {
    const fromLen = from.length;
    let output = "";
    let pos = 0;
    for (;;) {
        let matchPos = input.indexOf(from, pos);
        if (matchPos === -1) {
            output += input.slice(pos);
            break;
        }
        output += input.slice(pos, matchPos);
        output += to;
        pos = matchPos + fromLen;
    }
    return output;
}

function addMessage(object) {
    console.log(object);
    messages .className = "";
    let message = new Message(object);
    messages.appendChild(message.createEl());
    messages.style.bottom = '-' + message.element.offsetHeight + 'px';
    messages.className = "slide";
};

function onWindowResize() {
    messages.style.width = window.innerWidth + 'px';
}

let messages = document.getElementById('messages');
let socket = io();
socket.on('message', addMessage);
window.addEventListener('resize', onWindowResize, false);
onWindowResize();