// ==UserScript==
// @name               ChatGPT LaTeX Auto Render (OpenAI, new bing, you, etc.)
// @version            0.6.2
// @author             Scruel Tao
// @homepage           https://github.com/scruel/tampermonkey-scripts
// @description        Auto typeset LaTeX math formulas on ChatGPT pages (OpenAI, new bing, you, etc.).
// @description:zh-CN  自动渲染 ChatGPT 页面 (OpenAI, new bing, you 等) 上的 LaTeX 数学公式。
// @match              https://chat.openai.com/*
// @match              https://platform.openai.com/playground/*
// @match              https://www.bing.com/search?*
// @match              https://you.com/search?*&tbm=youchat*
// @match              https://www.you.com/search?*&tbm=youchat*
// @namespace          http://tampermonkey.net/
// @icon               https://chat.openai.com/favicon.ico
// @grant              none
// @noframes
// @downloadURL none
// ==/UserScript==

'use strict';

const PARSED_MARK = '_sc_parsed';
const MARKDOWN_RERENDER_MARK = 'sc_mktag';

const MARKDOWN_SYMBOL_UNDERLINE = 'XXXSCUEDLXXX'
const MARKDOWN_SYMBOL_ASTERISK = 'XXXSCAESKXXX'

function queryAddNoParsed(query) {
    return query + ":not([" + PARSED_MARK + "])";
}

function showTipsElement() {
    const tipsElement = window._sc_ChatLatex.tipsElement;
    tipsElement.style.position = "fixed";
    tipsElement.style.right = "10px";
    tipsElement.style.top = "10px";
    tipsElement.style.background = '#333';
    tipsElement.style.color = '#fff';
    tipsElement.style.zIndex = '999999';
    var tipContainer = document.body.querySelector('header');
    if (!tipContainer) {
        tipContainer = document.body;
    }
    tipContainer.appendChild(tipsElement);
}

function setTipsElementText(text, errorRaise=false) {
    window._sc_ChatLatex.tipsElement.innerHTML = text;
    if (errorRaise) {
        throw text;
    }
    console.log(text);
}

async function addScript(url) {
    const scriptElement = document.createElement('script');
    const headElement = document.getElementsByTagName('head')[0] || document.documentElement;
    if (!headElement.appendChild(scriptElement)) {
        // Prevent appendChild overwritten problem.
        headElement.append(scriptElement);
    }
    scriptElement.src = url;
}

function traverseDOM(element, callback, onlySingle=true) {
    if (!onlySingle || !element.hasChildNodes()) {
        callback(element);
    }
    element = element.firstChild;
    while (element) {
        traverseDOM(element, callback, onlySingle);
        element = element.nextSibling;
    }
}

function getExtraInfoAddedMKContent(content) {
    // Ensure that the whitespace before and after the same
    content = content.replaceAll(/( *\*+ *)/g, MARKDOWN_SYMBOL_ASTERISK + '$1');
    content = content.replaceAll(/( *_+ *)/g, MARKDOWN_SYMBOL_UNDERLINE + '$1');
    // Ensure render for single line
    content = content.replaceAll(new RegExp(`^${MARKDOWN_SYMBOL_ASTERISK}(\\*+)`, 'gm'), `${MARKDOWN_SYMBOL_ASTERISK} $1`);
    content = content.replaceAll(new RegExp(`^${MARKDOWN_SYMBOL_UNDERLINE}(_+)`, 'gm'), `${MARKDOWN_SYMBOL_UNDERLINE} $1`);
    return content;
}

function removeMKExtraInfo(ele) {
    traverseDOM(ele, function(e) {
        if (e.textContent){
            e.textContent = e.textContent.replaceAll(MARKDOWN_SYMBOL_UNDERLINE, '');
            e.textContent = e.textContent.replaceAll(MARKDOWN_SYMBOL_ASTERISK, '');
        }
    });
}

function getLastMKSymbol(ele, defaultSymbol) {
    if (!ele) { return defaultSymbol; }
    const content = ele.textContent.trim();
    if (content.endsWith(MARKDOWN_SYMBOL_UNDERLINE)) { return '_'; }
    if (content.endsWith(MARKDOWN_SYMBOL_ASTERISK)) { return '*'; }
    return defaultSymbol;
}

function restoreMarkdown(msgEle, tagName, defaultSymbol) {
    const eles = msgEle.querySelectorAll(tagName);
    eles.forEach(e => {
        const restoredNodes = document.createRange().createContextualFragment(e.innerHTML);
        const fn = restoredNodes.childNodes[0];
        const ln = restoredNodes.childNodes[restoredNodes.childNodes.length - 1]
        const wrapperSymbol = getLastMKSymbol(e.previousSibling, defaultSymbol);
        fn.textContent = wrapperSymbol + fn.textContent;
        ln.textContent = ln.textContent + wrapperSymbol;
        restoredNodes.prepend(document.createComment(MARKDOWN_RERENDER_MARK + "|0|" + tagName + "|" + wrapperSymbol.length));
        restoredNodes.append(document.createComment(MARKDOWN_RERENDER_MARK + "|1|" + tagName));
        e.parentElement.insertBefore(restoredNodes, e);
        e.parentNode.removeChild(e);
    });
    removeMKExtraInfo(msgEle);
}

function restoreAllMarkdown(msgEle) {
    restoreMarkdown(msgEle, 'em', '_');
}

function rerenderAllMarkdown(msgEle) {
    // restore HTML from restored markdown comment info
    const startComments = [];
    traverseDOM(msgEle, function(n) {
        if (n.nodeType !== 8){
            return;
        }
        const text = n.textContent.trim();
        if (!text.startsWith(MARKDOWN_RERENDER_MARK)) {
            return;
        }
        const tokens = text.split('|');
        if (tokens[1] === '0'){
            startComments.push(n);
        }
    });
    // Reverse to prevent nested elements
    startComments.reverse().forEach((n) => {
        const tokens = n.textContent.trim().split('|');
        const tagName = tokens[2];
        const tagRepLen = tokens[3];
        const tagEle = document.createElement(tagName);
        n.parentElement.insertBefore(tagEle, n);
        n.parentNode.removeChild(n);
        let subEle = tagEle.nextSibling;
        while (subEle){
            if (subEle.nodeType == 8) {
                const text = subEle.textContent.trim();
                if (text.startsWith(MARKDOWN_RERENDER_MARK) && text.split('|')[1] === '1') {
                    subEle.parentNode.removeChild(subEle);
                    break;
                }
            }
            tagEle.appendChild(subEle);
            subEle = tagEle.nextSibling;
        }
        // Remove previously added markdown symbols.
        tagEle.firstChild.textContent = tagEle.firstChild.textContent.substring(tagRepLen);
        tagEle.lastChild.textContent = tagEle.lastChild.textContent.substring(0, tagEle.lastChild.textContent.length - tagRepLen);
    });
}

async function prepareScript() {
    window._sc_beforeTypesetMsgEle = (msgEle) => {};
    window._sc_afterTypesetMsgEle = (msgEle) => {};
    window._sc_typeset = () => {
        try {
            const msgEles = window._sc_getMsgEles();
            msgEles.forEach(msgEle => {
                restoreAllMarkdown(msgEle);
                msgEle.setAttribute(_parsed_mark,'');

                window._sc_beforeTypesetMsgEle(msgEle);
                MathJax.typesetPromise([msgEle]);
                window._sc_afterTypesetMsgEle(msgEle);

                rerenderAllMarkdown(msgEle);
            });
        } catch (e) {
            console.warn(e);
        }
    }
    window._sc_mutationHandler = (mutation) => {
        if (mutation.oldValue === '') {
            window._sc_typeset();
        }
    };
    window._sc_chatLoaded = () => { return true; };
    window._sc_getObserveElement = () => { return null; };
    var observerOptions = {
        attributeOldValue : true,
        attributeFilter: ['cancelable', 'disabled'],
    };
    var afterMainOvservationStart = () => { window._sc_typeset(); };

    // Handle special cases per site.
    if (window.location.host === "www.bing.com") {
        window._sc_getObserveElement = () => {
            const ele = document.querySelector("#b_sydConvCont > cib-serp");
            if (!ele) {return null;}
            return ele.shadowRoot.querySelector("#cib-action-bar-main");
        }

        const getContMsgEles = (cont, isInChat=true) => {
            if (!cont) {
                return [];
            }
            const allChatTurn = cont.shadowRoot.querySelector("#cib-conversation-main").shadowRoot.querySelectorAll("cib-chat-turn");
            var lastChatTurnSR = allChatTurn[allChatTurn.length - 1];
            if (isInChat) { lastChatTurnSR = lastChatTurnSR.shadowRoot; }
            const allCibMsgGroup = lastChatTurnSR.querySelectorAll("cib-message-group");
            const allCibMsg = Array.from(allCibMsgGroup).map(e => Array.from(e.shadowRoot.querySelectorAll("cib-message"))).flatMap(e => e);
            return Array.from(allCibMsg).map(cibMsg => cibMsg.shadowRoot.querySelector("cib-shared")).filter(e => e);
        }
        window._sc_getMsgEles = () => {
            try {
                const convCont = document.querySelector("#b_sydConvCont > cib-serp");
                const tigerCont = document.querySelector("#b_sydTigerCont > cib-serp");
                return getContMsgEles(convCont).concat(getContMsgEles(tigerCont, false));
            } catch (ignore) {
                return [];
            }
        }
    }
    else if (window.location.host === "chat.openai.com") {
        window._sc_getObserveElement = () => {
            return document.querySelector("main form textarea+button");
        }
        window._sc_chatLoaded = () => { return document.querySelector('main div.text-sm>svg.animate-spin') === null; };

        observerOptions = { childList : true };

        afterMainOvservationStart = () => {
            window._sc_typeset();
            // Handle conversation switch
            new MutationObserver((mutationList) => {
                mutationList.forEach(async (mutation) => {
                    if (mutation.addedNodes){
                        window._sc_typeset();
                        startMainOvservation(await getMainObserveElement(true), observerOptions);
                    }
                });
            }).observe(document.querySelector('#__next'), {childList: true});
        };

        window._sc_mutationHandler = (mutation) => {
            mutation.addedNodes.forEach(e => {
                if (e.tagName === "svg") {
                    window._sc_typeset();
                }
            })
        };

        window._sc_getMsgEles = () => {
            return document.querySelectorAll(queryAddNoParsed("div.w-full div.text-base div.items-start"));
        }

        window._sc_beforeTypesetMsgEle = (msgEle) => {
            // Prevent latex typeset conflict
            const displayEles = msgEle.querySelectorAll('.math-display');
            displayEles.forEach(e => {
                const texEle = e.querySelector(".katex-mathml annotation");
                e.removeAttribute("class");
                e.textContent = "$$" + texEle.textContent + "$$";
            });
            const inlineEles = msgEle.querySelectorAll('.math-inline');
            inlineEles.forEach(e => {
                const texEle = e.querySelector(".katex-mathml annotation");
                e.removeAttribute("class");
                // e.textContent = "$" + texEle.textContent + "$";
                // Mathjax will typeset this with display mode.
                e.textContent = "$$" + texEle.textContent + "$$";

            });
        };
        window._sc_afterTypesetMsgEle = (msgEle) => {
            // https://github.com/mathjax/MathJax/issues/3008
            msgEle.style.display = 'unset';
        }
    }
    else if (window.location.host === "you.com" || window.location.host === "www.you.com") {
        window._sc_getObserveElement = () => {
            return document.querySelector('#chatHistory');
        };
        window._sc_chatLoaded = () => { return document.querySelector('#chatHistory div[data-pinnedconversationturnid]'); };
        observerOptions = { childList : true };

        window._sc_mutationHandler = (mutation) => {
            mutation.addedNodes.forEach(e => {
                const attr = e.getAttribute('data-testid')
                if (attr && attr.startsWith("youchat-convTurn")) {
                    startTurnAttrObservationForTypesetting(e, 'data-pinnedconversationturnid');
                }
            })
        };

        window._sc_getMsgEles = () => {
            return document.querySelectorAll(queryAddNoParsed('#chatHistory div[data-testid="youchat-answer"]'));
        };
    }
    console.log('Waiting for chat loading...')
    const mainElement = await getMainObserveElement();
    console.log('Chat loaded.')
    startMainOvservation(mainElement, observerOptions);
    afterMainOvservationStart();
}

function enbaleResultPatcher() {
    // TODO: refractor all code.
    if (window.location.host !== "chat.openai.com") {
        return;
    }
    const oldJSONParse = JSON.parse;
    JSON.parse = function _parse() {
        if (typeof arguments[0] == "object") {
            return arguments[0];
        }
        const res = oldJSONParse.apply(this, arguments);
        if (res.hasOwnProperty('message')){
            const message = res.message;
            if (message.hasOwnProperty('end_turn') && message.end_turn){
                message.content.parts[0] = getExtraInfoAddedMKContent(message.content.parts[0]);
            }
        }
        return res;
    };

    const responseHandler = (response, result) => {
        if (result.hasOwnProperty('mapping') && result.hasOwnProperty('current_node')){
            Object.keys(result.mapping).forEach((key) => {
                const mapObj = result.mapping[key];
                if (mapObj.hasOwnProperty('message')) {
                    if (mapObj.message.author.role === 'user'){
                        return;
                    }
                    const contentObj = mapObj.message.content;
                    contentObj.parts[0] = getExtraInfoAddedMKContent(contentObj.parts[0]);
                }
            });
        }
    }
    let oldfetch = fetch;
    function patchedFetch() {
        return new Promise((resolve, reject) => {
            oldfetch.apply(this, arguments).then(response => {
                const oldJson = response.json;
                response.json = function() {
                    return new Promise((resolve, reject) => {
                        oldJson.apply(this, arguments).then(result => {
                            try{
                                responseHandler(response, result);
                            } catch (e) {
                                console.warn(e);
                            }
                            resolve(result);
                        });
                    });
                }
                resolve(response);
            });
        });
    }
    window.fetch = patchedFetch;
}

// After output completed, the attribute of turn element will be changed,
// only with observer won't be enough, so we have this function for sure.
function startTurnAttrObservationForTypesetting(element, doneWithAttr) {
    const tmpObserver = new MutationObserver((mutationList, observer) => {
        mutationList.forEach(mutation => {
            if (mutation.oldValue === null) {
                window._sc_typeset();
                observer.disconnect;
            }
        })
    });
    tmpObserver.observe(element, {
        attributeOldValue : true,
        attributeFilter: [doneWithAttr],
    });
    if (element.hasAttribute(doneWithAttr)) {
        window._sc_typeset();
        tmpObserver.disconnect;
    }
}

function getMainObserveElement(chatLoaded=false) {
    return new Promise(async (resolve, reject) => {
        const resolver = () => {
            const ele = window._sc_getObserveElement();
            if (ele && (chatLoaded || window._sc_chatLoaded())) {
                return resolve(ele);
            }
            window.setTimeout(resolver, 500);
        }
        resolver();
    });
}

function startMainOvservation(mainElement, observerOptions) {
    const callback = (mutationList, observer) => {
        mutationList.forEach(mutation => {
            window._sc_mutationHandler(mutation);
        });
    };
    if (window._sc_mainObserver) {
        window._sc_mainObserver.disconnect();
    }
    window._sc_mainObserver = new MutationObserver(callback);
    window._sc_mainObserver.observe(mainElement, observerOptions);
}

async function waitMathJaxLoaded() {
    while (!MathJax.hasOwnProperty('typeset')) {
        if (window._sc_ChatLatex.loadCount > 20000 / 200) {
            setTipsElementText("Failed to load MathJax, try refresh.", true);
        }
        await new Promise((x) => setTimeout(x, 500));
        window._sc_ChatLatex.loadCount += 1;
    }
}

function hideTipsElement(timeout=3) {
    window.setTimeout(() => {window._sc_ChatLatex.tipsElement.hidden=true; }, 3000);
}

async function loadMathJax() {
    showTipsElement();
    setTipsElementText("Loading MathJax...");
    addScript('https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js');
    await waitMathJaxLoaded();
    setTipsElementText("MathJax Loaded.");
    hideTipsElement();
}

(async function() {
    window._sc_ChatLatex = {
        tipsElement: document.createElement("div"),
        loadCount: 0
    };
    window.MathJax = {
        tex: {
            inlineMath: [['$', '$'], ['\\(', '\\)']],
            displayMath  : [['$$', '$$', ['\\[', '\\]']]]
        },
        startup: {
            typeset: false
        }
    };

    enbaleResultPatcher();
    await loadMathJax();
    await prepareScript();
})();