// ==UserScript==
// @name         超星学习通作业/考试一键导出为Word(docx)
// @namespace    http://tampermonkey.net/
// @version      2.6
// @description  自动抓取学习通作业/考试题目、选项、正确答案、解析，并生成Word文档。完美修复题号重复问题，支持图片，支持自定义标题。
// @author       Restrl.
// @match        *://*.chaoxing.com/mooc2/work/view*
// @match        *://*.chaoxing.com/mooc-ans/mooc2/work/view*
// @match        *://*.chaoxing.com/exam/test/reVersionTestStartNew*
// @match        *://*.chaoxing.com/exam-ans/*
// @require      https://cdn.jsdelivr.net/npm/docx@7.1.0/build/index.js
// @require      https://cdn.jsdelivr.net/npm/file-saver@2.0.5/dist/FileSaver.min.js
// @grant        GM_xmlhttpRequest
// ==/UserScript==

(function() {
    'use strict';

    const { Document, Packer, Paragraph, TextRun, ImageRun, HeadingLevel, AlignmentType } = docx;

    function addExportButton() {
        if (document.querySelector('#exportBtn')) return;
        const btn = document.createElement('button');
        btn.id = 'exportBtn';
        btn.innerText = '📤 导出为 Word';
        btn.style.cssText = `
            position: fixed; top: 20px; right: 20px; z-index: 9999;
            padding: 10px 20px; background-color: #00a1d6; color: white;
            border: none; border-radius: 5px; cursor: pointer;
            box-shadow: 0 4px 6px rgba(0,0,0,0.1); font-weight: bold; font-size: 14px;
        `;
        btn.onclick = startExport;
        document.body.appendChild(btn);
    }

    async function urlToBlob(url) {
        return new Promise((resolve) => {
            if (url.startsWith('data:image')) {
                fetch(url).then(res => res.blob()).then(resolve).catch(() => resolve(null));
                return;
            }
            GM_xmlhttpRequest({
                method: "GET", url: url, responseType: "blob",
                onload: (res) => resolve(res.response),
                onerror: () => resolve(null)
            });
        });
    }

    async function parseRichText(element) {
        const runs = [];
        if (!element) return runs;
        
        const nodes = element.childNodes;
        for (const node of nodes) {
            if (node.nodeType === Node.TEXT_NODE) {
                const text = node.textContent.trim();
                // 过滤掉可能存在的单独的题号文本（如 "1. "）
                // 但这里不能太激进，防止误杀题干里的数字，主要靠外部逻辑控制
                if (text) runs.push(new TextRun({ text: text }));
            } else if (node.nodeType === Node.ELEMENT_NODE) {
                if (node.tagName === 'IMG') {
                    const src = node.src;
                    if (src) {
                        const imgBlob = await urlToBlob(src);
                        if (imgBlob) {
                            const imgBuffer = await imgBlob.arrayBuffer();
                            runs.push(new TextRun({ text: "\n" }));
                            runs.push(new ImageRun({
                                data: imgBuffer,
                                transformation: { width: 400, height: 300 },
                            }));
                            runs.push(new TextRun({ text: "\n" }));
                        }
                    }
                } else if (node.tagName === 'BR') {
                    runs.push(new TextRun({ text: "\n" }));
                } else if (['P', 'DIV', 'SPAN', 'H3', 'STRONG', 'B', 'SUB', 'SUP'].includes(node.tagName)) {
                    const childRuns = await parseRichText(node);
                    runs.push(...childRuns);
                    if (node.tagName === 'P') runs.push(new TextRun({ text: "\n" }));
                }
            }
        }
        return runs;
    }

    function getQuestionNodes() {
        let q = document.querySelectorAll('.aiArea');
        if (q.length > 0) return q;
        q = document.querySelectorAll('.questionLi');
        if (q.length > 0) return q;
        return document.querySelectorAll('.TiMu');
    }

    function getAssignmentTitle() {
        const titleNode = document.querySelector('h2.mark_title');
        if (titleNode) {
            return titleNode.innerText.trim();
        }
        let fallback = document.title || "作业导出";
        return fallback.split(/[|\-_]/)[0].trim();
    }

    async function startExport() {
        const btn = document.querySelector('#exportBtn');
        btn.innerText = '⏳ 正在处理...';
        btn.disabled = true;

        let docTitle = getAssignmentTitle();
        const safeFilename = docTitle.replace(/[\\/:*?"<>|]/g, '_');

        const docChildren = [];
        docChildren.push(new Paragraph({
            text: docTitle,
            heading: HeadingLevel.HEADING_1,
            alignment: AlignmentType.CENTER
        }));
        docChildren.push(new Paragraph({ text: "" }));

        const questions = getQuestionNodes();
        console.log(`精准捕获到 ${questions.length} 道题目`);

        for (let i = 0; i < questions.length; i++) {
            const qBox = questions[i];
            const titleNode = qBox.querySelector('h3.mark_name');
            if (!titleNode) continue;

            const fullTitleText = titleNode.innerText;
            const isFillIn = fullTitleText.includes("填空");
            
            // --- 核心修复区：完美去重题号 ---
            let richTextRuns = [];
            
            // 策略1：精准提取（针对你的页面结构）
            // 只抓取 "题目类型" 和 "题目内容"，无视 h3 下那个游荡的文本节点 "1. "
            const typeNode = titleNode.querySelector('.colorShallow'); // (单选题)
            const contentNode = titleNode.querySelector('.qtContent'); // 题目正文
            
            if (contentNode) {
                // 如果能找到正文容器，就只解析它和类型
                if (typeNode) {
                     richTextRuns.push(...await parseRichText(typeNode));
                     richTextRuns.push(new TextRun({ text: " " })); // 加个空格美观
                }
                richTextRuns.push(...await parseRichText(contentNode));
            } else {
                // 策略2：兜底方案（针对老旧页面）
                // 如果找不到 contentNode，说明结构比较老，只能暴力清洗
                const cloneTitle = titleNode.cloneNode(true);
                // 移除可能的序号 span
                const indexSpan = cloneTitle.querySelector('span:first-child');
                if(indexSpan && /^\d+/.test(indexSpan.innerText)) indexSpan.remove();
                
                richTextRuns = await parseRichText(cloneTitle);
                
                // 暴力正则：移除开头的 "数字+点/顿号/空格"
                if(richTextRuns.length > 0 && richTextRuns[0].text) {
                     richTextRuns[0].text = richTextRuns[0].text.replace(/^[\s\d.、．]+/, "").trim();
                }
            }

            // 写入文档：使用我们生成的 i+1 作为序号
            docChildren.push(new Paragraph({
                children: [
                    new TextRun({ text: `${i + 1}. `, bold: true, size: 24 }), 
                    ...richTextRuns
                ]
            }));

            // 选项处理
            if (!isFillIn) {
                const optionUl = qBox.querySelector('ul.mark_letter');
                if (optionUl) {
                    const options = optionUl.querySelectorAll('li');
                    for (const opt of options) {
                        const optRuns = await parseRichText(opt);
                        docChildren.push(new Paragraph({
                            children: optRuns,
                            indent: { left: 720 }
                        }));
                    }
                }
            }

            // 答案处理
            let ansText = "";
            const ansDiv = qBox.querySelector('.mark_answer');
            if (ansDiv) {
                const fillDiv = ansDiv.querySelector('.mark_fill');
                if (fillDiv) {
                    ansText = fillDiv.innerText.replace(/正确答案[:：]?/g, "").trim();
                } 
                if (!ansText) {
                    const greenSpan = ansDiv.querySelector('.mark_key .colorGreen');
                    if (greenSpan) {
                         ansText = greenSpan.innerText.replace(/正确答案[:：]?/g, "").trim();
                    } else {
                        const keyDiv = ansDiv.querySelector('.mark_key');
                        if (keyDiv) {
                             const raw = keyDiv.innerText.trim();
                             if (raw.includes("正确答案")) {
                                 ansText = raw.split("正确答案")[1].trim();
                             } else if (!raw.includes("我的答案")) {
                                 ansText = raw;
                             }
                        }
                    }
                }
            }

            if (ansText) {
                ansText = ansText.replace(/^[:：\s]+/, "");
                docChildren.push(new Paragraph({
                    children: [
                        new TextRun({ text: "【正确答案】：", bold: true, color: "FF0000" }),
                        new TextRun({ text: ansText, bold: true, color: "FF0000" })
                    ]
                }));
            }

            // 解析处理
            const analysisDiv = qBox.querySelector('.analysisDiv, .mark_answer_analysis');
            if (analysisDiv) {
                const analysisContent = analysisDiv.querySelector('.qtAnalysis, .text');
                if (analysisContent) {
                    const analysisRuns = await parseRichText(analysisContent);
                    docChildren.push(new Paragraph({
                        children: [
                            new TextRun({ text: "【解析】：", bold: true, italics: true, color: "0000FF" }),
                            ...analysisRuns
                        ]
                    }));
                }
            }

            docChildren.push(new Paragraph({ text: "--------------------------------------------------", color: "CCCCCC" }));
            docChildren.push(new Paragraph({ text: "" }));
        }

        try {
            const doc = new Document({ sections: [{ children: docChildren }] });
            const blob = await Packer.toBlob(doc);
            saveAs(blob, `${safeFilename}.docx`);
            
            btn.innerText = '✅ 导出成功';
            setTimeout(() => { btn.innerText = '📤 导出为 Word'; btn.disabled = false; }, 3000);
        } catch (e) {
            console.error(e);
            alert("导出出错，详细错误请看F12控制台");
            btn.innerText = '❌ 出错';
        }
    }

    window.addEventListener('load', addExportButton);
})();