Custom Chat Tags

// ==UserScript==
// @name         Custom Tags for OWOT
// @namespace    http://tampermonkey.net/
// @version      1.1
// @description  Highly compressed custom tag system using Base128 binary bit-packing into invisible characters. Safely supports HTML formatting.
// @author       gimmickCellar
// @match        *://*.ourworldoftext.com/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    const TAG_START = 0xE0000;

    let myTag = localStorage.getItem("customChatTag") || "";
    let myTagColor = localStorage.getItem("customChatTagColor") || "#aaaaaa";

    // --- HTML Sanitization (XSS Protection) ---
    function sanitizeHTML(html) {
        if (!html) return "";
        let doc = new DOMParser().parseFromString(html, 'text/html');
        let walker = doc.createTreeWalker(doc.body, NodeFilter.SHOW_ELEMENT, null, false);
        let nodesToRemove = [];

        // Only allow basic text formatting tags
        const ALLOWED_TAGS = ['B', 'I', 'U', 'S', 'SPAN', 'STRONG', 'EM', 'MARK', 'SUB', 'SUP', 'CODE', 'DEL'];
        const ALLOWED_ATTRS = ['style', 'title'];

        let node;
        while (node = walker.nextNode()) {
            if (!ALLOWED_TAGS.includes(node.tagName)) {
                nodesToRemove.push(node);
            } else {
                // Sanitize attributes
                for (let i = node.attributes.length - 1; i >= 0; i--) {
                    let attr = node.attributes[i];
                    if (!ALLOWED_ATTRS.includes(attr.name.toLowerCase())) {
                        node.removeAttribute(attr.name);
                    } else if (attr.name.toLowerCase() === 'style') {
                        // Prevent CSS injection that breaks the layout or executes code
                        if (/(expression|url|behavior|position|display|transform|margin|padding|top|left|right|bottom|z-index|float|clear)/i.test(attr.value)) {
                            node.removeAttribute('style');
                        }
                    }
                }
            }
        }

        // Remove bad nodes, but keep their internal text so message context isn't lost
        for (let i = nodesToRemove.length - 1; i >= 0; i--) {
            let n = nodesToRemove[i];
            let text = document.createTextNode(n.textContent);
            n.parentNode.replaceChild(text, n);
        }

        return doc.body.innerHTML;
    }

    function escapeHtml(str) {
        return String(str).replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
    }

    // --- Compression & Binary Utilities ---
    function hexToRgb(hex) {
        hex = hex.replace(/^#/, '');
        if (hex.length === 3) hex = hex.split('').map(c => c+c).join('');
        let int = parseInt(hex, 16) || 0;
        return [(int >> 16) & 0xFF, (int >> 8) & 0xFF, int & 0xFF];
    }

    function rgbToHex(r, g, b) {
        return "#" + (1 << 24 | r << 16 | g << 8 | b).toString(16).slice(1);
    }

    function packBase128(bytes) {
        let packed = [];
        let current = 0, bits = 0;
        for (let i = 0; i < bytes.length; i++) {
            current = (current << 8) | bytes[i];
            bits += 8;
            while (bits >= 7) {
                bits -= 7;
                packed.push((current >> bits) & 0x7F);
            }
        }
        if (bits > 0) {
            packed.push((current << (7 - bits)) & 0x7F);
        }
        return packed;
    }

    function unpackBase128(packed) {
        let bytes = [];
        let current = 0, bits = 0;
        for (let i = 0; i < packed.length; i++) {
            current = (current << 7) | packed[i];
            bits += 7;
            while (bits >= 8) {
                bits -= 8;
                bytes.push((current >> bits) & 0xFF);
            }
        }
        return bytes;
    }

    // --- Encoding & Decoding ---
    function encodeTag(tagStr, colorStr) {
        if (!tagStr) return "";
        let [r, g, b] = hexToRgb(colorStr);
        let textBytes = new TextEncoder().encode(tagStr);

        let payload = new Uint8Array(3 + textBytes.length);
        payload[0] = r; payload[1] = g; payload[2] = b;
        payload.set(textBytes, 3);

        let packed7Bit = packBase128(payload);

        let result = "";
        for(let i = 0; i < packed7Bit.length; i++) {
            result += String.fromCodePoint(TAG_START + packed7Bit[i]);
        }
        return result;
    }

    function decodeTag(msg) {
        if (typeof msg !== "string") return null;
        let packed7Bit = [];
        let i = 0;

        while (i < msg.length) {
            let cp = msg.codePointAt(i);
            if (cp >= TAG_START && cp <= 0xE007F) {
                packed7Bit.push(cp - TAG_START);
                i += 2;
            } else {
                break;
            }
        }

        if (packed7Bit.length === 0) return null;

        try {
            let bytes = unpackBase128(packed7Bit);
            if (bytes.length < 3) return null;

            let colorStr = rgbToHex(bytes[0], bytes[1], bytes[2]);
            let tagBytes = new Uint8Array(bytes.slice(3));
            let tagStr = new TextDecoder().decode(tagBytes);

            return { tag: tagStr, color: colorStr, lengthConsumed: i };
        } catch(e) {
            return null;
        }
    }

    // --- OWOT Integration ---

    // 1. Intercept outgoing messages
    OWOT.on("chatSend", function(e) {
        if (!myTag || e.message.trim().length === 0 || e.message.startsWith("/")) return;

        let encoded = encodeTag(myTag, myTagColor);
        let msgLim = state.userModel.is_staff ? 3030 : 400;

        if (encoded.length + e.message.length > msgLim) {
            e.message = e.message.substring(0, Math.max(0, msgLim - encoded.length));
        }

        e.message = encoded + e.message;
    });

    // 2. Intercept incoming messages AND chat history right before render
    if (typeof window.addChat === "function") {
        const originalAddChat = window.addChat;

        window.addChat = function(chatfield, id, type, nickname, message, realUsername, op, admin, staff, color, date, dataObj) {
            if (id === 0 && realUsername === "[ Server ]") {
                return originalAddChat.apply(this, arguments);
            }

            let decoded = decodeTag(message);
            if (decoded) {
                // Strip the invisible characters from the message
                message = message.slice(decoded.lengthConsumed);

                // Sanitize the HTML payload
                let tagText = sanitizeHTML(decoded.tag);
                let tagColor = escapeHtml(decoded.color);

                if (!dataObj) dataObj = {};

                let origRankName = dataObj.rankName;
                let origRankColor = dataObj.rankColor;

                if (!origRankName) {
                    if (op) { origRankName = "OP"; origRankColor = "#0033cc"; op = false; }
                    else if (admin) { origRankName = "A"; origRankColor = "#FF0000"; admin = false; }
                    else if (staff) { origRankName = "M"; origRankColor = "#009933"; staff = false; }
                }

                if (origRankName) {
                    // Combine tags safely
                    dataObj.rankName = tagText + `)&nbsp;<span style="color:${origRankColor}; font-weight:bold">(` + origRankName;
                    dataObj.rankColor = tagColor;
                } else {
                    dataObj.rankName = tagText;
                    dataObj.rankColor = tagColor;
                }
            }

            // Call original renderer with our modified arguments
            return originalAddChat.call(this, chatfield, id, type, nickname, message, realUsername, op, admin, staff, color, date, dataObj);
        };
    } else {
        console.warn("OWOT Invisible Chat Tags: window.addChat not found!");
    }

    // 3. Command hooks
    OWOT.chat.registerCommand("tag", function(args) {
        myTag = args.join(" ").trim();
        localStorage.setItem("customChatTag", myTag);

        let safePreview = sanitizeHTML(myTag);
        clientChatResponse(myTag ? "Chat tag set to: " + safePreview : "Chat tag disabled.");
    }, ["text/html"], "Set your custom invisible chat tag (HTML supported)");

    OWOT.chat.registerCommand("tagcolor", function(args) {
        if (!args[0]) return clientChatResponse("Current tag color: " + myTagColor);
        myTagColor = args[0];
        localStorage.setItem("customChatTagColor", myTagColor);
        clientChatResponse("Chat tag color set to: " + myTagColor);
    }, ["color"], "Set the default color of your chat tag");

    console.log("OWOT Compressed Invisible HTML Chat Tags loaded!");
})();