// ==UserScript==
// @name         BUCT cource helper
// @namespace    http://tampermonkey.net/
// @version      2025-03-12
// @description  北化在线助手
// @author       Bluemangoo
// @match        https://course.buct.edu.cn/meol/jpk/course/layout/newpage/index.jsp?*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=buct.edu.cn
// @grant        GM_registerMenuCommand
// @grant        GM_unregisterMenuCommand
// ==/UserScript==

(function () {
    "use strict";

    const HOST = "https://local.bluemangoo.net:3443";

    let question = {
        id: ""
    };

    class Poll {
        polling = true;

        constructor() {
            this.poll();
        }

        async poll() {
            if (!this.polling) {
                return;
            }
            let res;
            try {
                res = await fetch(`${HOST}/polling?env=course`, {
                    method: "GET",
                    headers: {
                        "Content-Type": "application/json"
                    }
                });
            } catch {
                await new Promise((resolve) => setTimeout(resolve, 1000));
                return this.poll();
            }
            this.poll();
            try {
                const data = await res.json();
                if (data.status !== "nothing") {
                    const { questionID, answer } = data.data;
                    console.log("回答", questionID, "\n", answer);
                    answerQuestion(questionID, answer);
                }
            } catch (e) {
                console.error(e);
            }
        }
    }

    function getAnswerElement() {
        const doc = document
            .getElementById("mainFrame")
            .contentDocument.getElementById("questionshow").contentDocument;
        return doc.getElementsByClassName("extable")[0];
    }

    function getContent() {
        const doc = document
            .getElementById("mainFrame")
            .contentDocument.getElementById("questionshow").contentDocument;
        const question = doc
            .getElementsByTagName("iframe")[0]
            .contentDocument.getElementById("body").innerText;
        const answer = doc.getElementsByClassName("extable")[0].innerText.replaceAll("\t", "- ");
        return question + answer;
    }

    function copyToClipboard() {
        navigator.clipboard.writeText(getContent());
    }

    function answerQuestion(id, answer) {
        if (id !== question.id) {
            return;
        }
        aiButton.value = "？";
        const answers = answer.split("\n");
        const children = getAnswerElement().children[0].children;
        for (const child of children) {
            if (child.classList[0] !== "optionContent") {
                continue;
            }
            if (answers.includes(child.innerText.replaceAll("\t", ""))) {
                child.children[0].children[0].click();
            }
        }
    }

    async function ask() {
        const q = getContent();
        const req = await fetch(`${HOST}/question`, {
            method: "POST",
            headers: {
                "Content-Type": "application/json"
            },
            body: JSON.stringify({
                question: q
            })
        });
        const data = await req.json();
        if (data.data.questionId) {
            question.id = data.data.questionId;
        }
        aiButton.value = "Zzz";
    }

    const flag = {
        copyButton: false,
        aiButton: false
    };

    let aiButton;
    let poll;

    function createButton(addAiButton = false) {
        const base = document.getElementById("mainFrame");
        const win = base.contentWindow;
        const doc = base.contentDocument;
        win.getContent = getContent;
        win.getAnswerElement = getAnswerElement;
        win.answerQuestion = answerQuestion;
        win.copyToClipboard = copyToClipboard;
        if (!flag.copyButton) {
            const button = doc.createElement("input");
            button.value = "复制";
            button.style = "margin-left: 10px;";
            button.type = "button";
            button.onclick = copyToClipboard;
            doc.getElementsByClassName("navigation")[0].childNodes[1].appendChild(button);
            flag.copyButton = true;
        }
        if (addAiButton && !flag.aiButton) {
            const button = doc.createElement("input");
            aiButton = button;
            button.value = "？";
            button.style = "margin-left: 10px;";
            button.type = "button";
            button.onclick = ask;
            doc.getElementsByClassName("navigation")[0].childNodes[1].appendChild(button);
            flag.aiButton = true;
        }
    }

    function initAiBridge() {
        createButton(true);
        if (poll) {
            poll.polling = false;
        }
        poll = new Poll();
    }

    function stopPolling() {
        if (poll) {
            poll.polling = false;
        }
    }

    GM_registerMenuCommand("添加复制按钮", createButton);
    GM_registerMenuCommand("初始化ai桥", initAiBridge);
    GM_registerMenuCommand("停止轮询", stopPolling);
})();