// ==UserScript==
// @name         超星学习通考试/测验题目提取 (完整解密+导出Word/TXT)
// @namespace    http://tampermonkey.net/
// @version      4.6
// @description  一键提取学习通章节测验的题目，自动彻底解密乱码（参考字体解密脚本），支持导出Word和TXT，UI美化并置顶。
// @author       2281046977
// @match        *://*.chaoxing.com/*
// @match        *://*.edu.cn/*
// @icon         http://pan-yz.chaoxing.com/favicon.ico
// @require      https://scriptcat.org/lib/668/1.0/TyprMd5.js
// @resource     Table https://www.forestpolice.org/ttf/2.0/table.json
// @grant        GM_getResourceText
// @grant        GM_setClipboard
// @grant        GM_addStyle
// @run-at       document-end
// ==/UserScript==

(function() {
    'use strict';

    // ================= 配置区 =================
    // 字体映射表缓存
    let fontHashParams = null;
    let currentFontData = null;
    let fontLoaded = false; // 标记是否成功加载了页面字体

    // ================= 样式表 =================
    // 使用最大z-index保证在最上层
    const MAX_Z_INDEX = 2147483647;

    const styles = `
        /* 侧边悬浮按钮 */
        #cx-tool-panel {
            position: fixed;
            top: 150px;
            left: 10px;
            z-index: ${MAX_Z_INDEX - 1};
            display: flex;
            flex-direction: column;
            gap: 10px;
        }
        .cx-btn {
            background-color: #4CAF50;
            color: white;
            padding: 10px 15px;
            border-radius: 6px;
            border: none;
            cursor: pointer;
            font-size: 14px;
            box-shadow: 0 4px 6px rgba(0,0,0,0.2);
            font-family: "Microsoft YaHei", sans-serif;
            text-align: center;
            transition: all 0.3s;
        }
        .cx-btn:hover { transform: translateY(-2px); box-shadow: 0 6px 8px rgba(0,0,0,0.25); }
        .cx-btn:active { transform: translateY(0); }
        
        .cx-btn.primary { background-color: #1890ff; }
        .cx-btn.success { background-color: #52c41a; }
        .cx-btn.warning { background-color: #faad14; }

        /* 弹窗遮罩 */
        #cx-preview-modal {
            position: fixed;
            top: 0; left: 0; width: 100vw; height: 100vh;
            background: rgba(0,0,0,0.6);
            backdrop-filter: blur(2px);
            z-index: ${MAX_Z_INDEX};
            display: none;
            justify-content: center;
            align-items: center;
        }
        /* 弹窗主体 */
        .cx-modal-content {
            background: white;
            width: 800px;
            max-width: 90%;
            height: 85vh;
            padding: 24px;
            border-radius: 12px;
            display: flex;
            flex-direction: column;
            box-shadow: 0 10px 25px rgba(0,0,0,0.5);
            animation: cxModalFadeIn 0.3s ease;
        }
        @keyframes cxModalFadeIn {
            from { opacity: 0; transform: scale(0.95); }
            to { opacity: 1; transform: scale(1); }
        }
        
        .cx-modal-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 16px;
            border-bottom: 1px solid #eee;
            padding-bottom: 16px;
        }
        .cx-modal-title { font-size: 20px; font-weight: bold; color: #333; }
        .cx-close-btn {
            cursor: pointer;
            font-size: 28px;
            color: #999;
            line-height: 20px;
            transition: color 0.2s;
        }
        .cx-close-btn:hover { color: #333; }

        #cx-preview-text {
            flex: 1;
            width: 100%;
            resize: none;
            padding: 16px;
            border: 1px solid #d9d9d9;
            border-radius: 6px;
            font-family: Consolas, Monaco, "Courier New", monospace;
            font-size: 14px;
            line-height: 1.6;
            overflow-y: auto;
            background: #f9f9f9;
            color: #333;
        }
        #cx-preview-text:focus { outline: 2px solid #1890ff; border-color: transparent; }

        .cx-modal-footer {
            margin-top: 16px;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .cx-status-text {
            font-size: 13px;
            color: #666;
            background: #f0f0f0;
            padding: 4px 8px;
            border-radius: 4px;
        }
        .cx-btn-group {
            display: flex;
            gap: 12px;
        }
    `;

    // ================= 解密核心逻辑 =================

    // 初始化解密表
    function initDecryption() {
        try {
            const tableText = GM_getResourceText('Table');
            if (tableText) {
                fontHashParams = JSON.parse(tableText);
                console.log('ChaoxingExtractor: 字体映射表加载成功, 条目数:', Object.keys(fontHashParams).length);
            } else {
                console.warn('ChaoxingExtractor: 字体映射表为空');
            }
        } catch (e) {
            console.error('ChaoxingExtractor: 加载字体映射表失败', e);
        }
    }

    // 解析当前页面的加密字体
    function parsePageFont() {
        // 优先查找包含 font-cxsecret 的 style 标签
        // 很多时候字体定义在很长的 base64 串中
        const styles = document.getElementsByTagName('style');
        let fontBase64 = null;

        for (let style of styles) {
            const content = style.textContent;
            if (content.includes('font-cxsecret') && content.includes('base64,')) {
                // 正则提取 base64 内容，兼容换行和不同结束符
                const match = content.match(/base64,([\w\W]+?)'/);
                if (match && match[1]) {
                    fontBase64 = match[1];
                    break;
                }
            }
        }

        if (fontBase64) {
            try {
                // 处理 Base64
                const binary_string = window.atob(fontBase64);
                const len = binary_string.length;
                const bytes = new Uint8Array(len);
                for (let i = 0; i < len; i++) {
                    bytes[i] = binary_string.charCodeAt(i);
                }

                // Typr 解析
                const font = Typr.parse(bytes)[0];
                currentFontData = font;
                fontLoaded = true;
                console.log('ChaoxingExtractor: 页面加密字体解析成功');
            } catch (e) {
                console.error('ChaoxingExtractor: 解析字体出错', e);
                fontLoaded = false;
            }
        } else {
            console.log('ChaoxingExtractor: 未在页面找到加密字体 (font-cxsecret) 或已无需解密');
            fontLoaded = false;
        }
    }

    // 获取MD5函数
    function getMd5Fn() {
        // 兼容各种加载方式
        if (typeof md5 === 'function') return md5;
        if (typeof Typr !== 'undefined' && typeof Typr.md5 === 'function') return Typr.md5;
        if (window.md5) return window.md5;
        return null;
    }

    // 将文本中的乱码解密 (关键修复)
    function decryptText(text) {
        if (!text) return "";
        // 如果没有字体数据或者映射表，直接返回原文本
        if (!fontHashParams || !currentFontData) return text;

        const md5Fn = getMd5Fn();
        if (!md5Fn) {
            console.warn('ChaoxingExtractor: 未找到MD5函数，无法解密');
            return text;
        }

        let result = "";
        for (let i = 0; i < text.length; i++) {
            const char = text[i];
            const code = char.charCodeAt(0);

            // 尝试获取字形索引
            const glyphIndex = Typr.U.codeToGlyph(currentFontData, code);

            // 如果 glyphIndex > 0，说明这个字符在这个自定义字体里有定义
            if (glyphIndex > 0) {
                // 获取字形路径
                const path = Typr.U.glyphToPath(currentFontData, glyphIndex);
                if (path) {
                    const pathStr = JSON.stringify(path);
                    
                    // 【关键修复】：参考“字体解密.js”，需要 slice(24) 截取后8位
                    const hash = md5Fn(pathStr).slice(24);

                    // 查找 hash 对应的文字
                    let match = fontHashParams[hash];

                    if (match) {
                        // 映射表中存储的是 unicode 编码 (int)，需要转回字符
                        // 有些表存的是字符，有些是int，做个兼容
                        if (typeof match === 'number') {
                            result += String.fromCharCode(match);
                        } else {
                            result += match;
                        }
                        continue; // 找到替换，跳过原字符
                    }
                }
            }
            // 没找到或者不用替换，保留原字符
            result += char;
        }
        return result;
    }

    // ================= 提取逻辑 =================

    function extractContent() {
        // 每次提取前尝试刷新一下字体解析
        parsePageFont();

        const questions = document.querySelectorAll('.TiMu');
        if (questions.length === 0) return null;

        let resultText = "";
        // 用于导出 Word 的 HTML 结构
        let rawHtml = `
            <html>
            <head>
                <meta charset='utf-8'>
                <title>学习通习题导出</title>
                <style>
                    body { font-family: 'SimSun', '宋体', serif; line-height: 1.6; }
                    .q-block { margin-bottom: 20px; border-bottom: 1px solid #eee; padding-bottom: 15px; }
                    .q-title { font-weight: bold; font-size: 16px; margin-bottom: 10px; }
                    .q-opt { margin-left: 20px; }
                    .q-ans { margin-top: 10px; background: #f5f5f5; padding: 8px; color: #d32f2f; font-weight: bold; }
                </style>
            </head>
            <body>
            <h1 style="text-align:center;">学习通习题导出</h1>
        `;

        questions.forEach((q, index) => {
            // --- 题目 ---
            let titleDiv = q.querySelector('.Zy_TItle .clearfix') || 
                           q.querySelector('.Zy_TItle') ||
                           q.querySelector('.newZy_TItle') ||
                           q.querySelector('.fontLabel'); // 兼容更多选择器

            // 深度清理文本，处理可能存在的隐藏元素
            let titleText = titleDiv ? titleDiv.innerText.replace(/\s+/g, ' ').trim() : "未找到题目";
            
            // 【解密】
            titleText = decryptText(titleText);

            resultText += `【${index + 1}】 ${titleText}\n`;
            rawHtml += `<div class="q-block"><p class="q-title">【${index + 1}】 ${titleText}</p><ul>`;

            // --- 选项 ---
            // 兼容 li 下直接是文本，或者 p 标签，或者 a 标签的情况
            const options = q.querySelectorAll('ul li');
            if (options.length > 0) {
                options.forEach(opt => {
                    let optText = opt.innerText.replace(/\s+/g, ' ').trim();
                    optText = decryptText(optText);

                    // 判断是否被选中/正确
                    const isChecked = opt.querySelector('input:checked') || opt.querySelector('.ri') || opt.querySelector('.dui');
                    const mark = isChecked ? " [已选]" : "";

                    resultText += `\t${optText}${mark}\n`;
                    rawHtml += `<li class="q-opt">${optText}${mark}</li>`;
                });
            }

            // --- 答案/解析提取 ---
            const answerDiv = q.querySelector('.newAnswerBx') || q.querySelector('.answerBx') || q.querySelector('.lookAnswer');

            if (answerDiv) {
                let answerBlockText = answerDiv.innerText.replace(/\s+/g, ' ').trim();
                answerBlockText = decryptText(answerBlockText);

                if (answerBlockText) {
                    resultText += `\n${answerBlockText}\n`;
                    rawHtml += `</ul><div class="q-ans">${answerBlockText}</div></div>`;
                } else {
                    rawHtml += `</ul></div>`;
                }
            } else {
                rawHtml += `</ul></div>`;
            }

            resultText += "\n----------------------------------------\n\n";
        });

        rawHtml += "</body></html>";
        return { text: resultText, html: rawHtml, count: questions.length };
    }

    // ================= 导出功能函数 =================
    
    // 获取动态文件名
    function getExportFileName(extension) {
        let name = "学习通题目";
        
        // 优先尝试用户指定的选择器
        const userSelector = document.querySelector("#RightCon > div.radiusBG > div > div.ceyan_name > h3");
        // 备用选择器
        const fallbackSelector = document.querySelector(".ceyan_name h3") || document.querySelector("h3");

        const target = userSelector || fallbackSelector;

        if (target && target.innerText) {
            name = target.innerText.replace(/\s+/g, ' ').trim();
        } else if (document.title) {
            name = document.title.replace(/\s+/g, ' ').trim();
        }

        // 去除文件名非法字符
        name = name.replace(/[\\/:*?"<>|]/g, "_");

        const date = new Date();
        const timeStr = `${date.getMonth()+1}月${date.getDate()}日`;
        
        return `${name}_${timeStr}.${extension}`;
    }

    function exportToWord(htmlContent) {
        const blob = new Blob(['\ufeff', htmlContent], { type: 'application/msword' });
        const url = URL.createObjectURL(blob);
        const link = document.createElement('a');
        link.href = url;
        link.download = getExportFileName('doc');
        document.body.appendChild(link);
        link.click();
        document.body.removeChild(link);
        URL.revokeObjectURL(url);
    }

    function exportToTxt(textContent) {
        const blob = new Blob([textContent], { type: 'text/plain;charset=utf-8' });
        const url = URL.createObjectURL(blob);
        const link = document.createElement('a');
        link.href = url;
        link.download = getExportFileName('txt');
        document.body.appendChild(link);
        link.click();
        document.body.removeChild(link);
        URL.revokeObjectURL(url);
    }

    function showModal(data) {
        let modal = document.getElementById('cx-preview-modal');
        // 状态文本
        const statusStr = `字体解密状态: ${fontLoaded ? '✅ 字体已解析' : '⚠️ 无加密字体'} | 映射表: ${fontHashParams ? '✅ 已加载' : '❌ 未加载'}`;

        if (!modal) {
            const modalHtml = `
                <div id="cx-preview-modal">
                    <div class="cx-modal-content">
                        <div class="cx-modal-header">
                            <span class="cx-modal-title">📝 题目预览 (共 ${data.count} 题)</span>
                            <span class="cx-close-btn" onclick="document.getElementById('cx-preview-modal').style.display='none'">&times;</span>
                        </div>
                        <textarea id="cx-preview-text" readonly></textarea>
                        <div class="cx-modal-footer">
                            <span class="cx-status-text" id="cx-status-info">${statusStr}</span>
                            <div class="cx-btn-group">
                                <button class="cx-btn primary" id="cx-copy-btn">复制全部</button>
                                <button class="cx-btn warning" id="cx-txt-btn">导出 TXT</button>
                                <button class="cx-btn success" id="cx-word-btn">导出 Word</button>
                            </div>
                        </div>
                    </div>
                </div>
            `;
            document.body.insertAdjacentHTML('beforeend', modalHtml);
            modal = document.getElementById('cx-preview-modal');

            // 绑定事件
            document.getElementById('cx-copy-btn').onclick = () => {
                const text = document.getElementById('cx-preview-text').value;
                GM_setClipboard(text);
                
                // 简单的提示动画
                const btn = document.getElementById('cx-copy-btn');
                const originalText = btn.innerText;
                btn.innerText = '已复制！';
                btn.style.backgroundColor = '#52c41a';
                setTimeout(() => {
                    btn.innerText = originalText;
                    btn.style.backgroundColor = '';
                }, 1500);
            };

            document.getElementById('cx-word-btn').onclick = () => {
                const currentData = extractContent(); // 重新获取以防变动
                if(currentData) exportToWord(currentData.html);
            };

            document.getElementById('cx-txt-btn').onclick = () => {
                const currentData = extractContent();
                if(currentData) exportToTxt(currentData.text);
            };
            
            // 点击遮罩关闭
            modal.onclick = (e) => {
                if (e.target === modal) modal.style.display = 'none';
            };

        } else {
            // 更新状态
            document.getElementById('cx-status-info').innerText = statusStr;
        }

        document.getElementById('cx-preview-text').value = data.text;
        modal.style.display = 'flex';
    }

    // ================= 初始化 =================

    function init() {
        // TiMu 是题目块，如果没有题目块则不显示按钮
        const check = document.querySelectorAll('.TiMu');
        if (check.length === 0) return;

        initDecryption();
        parsePageFont();

        const styleEl = document.createElement('style');
        styleEl.innerHTML = styles;
        document.head.appendChild(styleEl);

        const toolPanel = document.createElement('div');
        toolPanel.id = 'cx-tool-panel';

        // 主按钮：提取并预览
        const mainBtn = document.createElement('button');
        mainBtn.className = 'cx-btn primary';
        mainBtn.innerHTML = '📑 提取题目';
        mainBtn.title = '点击提取本页所有题目、选项及答案并预览';
        mainBtn.onclick = () => {
            const data = extractContent();
            if (data) {
                showModal(data);
            } else {
                alert('未找到题目，请确保在测验页面内');
            }
        };

        // 快速下载按钮组
        const downloadGroup = document.createElement('div');
        downloadGroup.style.display = 'flex';
        downloadGroup.style.gap = '5px'; // 按钮间距

        const wordBtn = document.createElement('button');
        wordBtn.className = 'cx-btn success';
        wordBtn.style.flex = '1'; // 均分宽度
        wordBtn.style.padding = '8px 5px';
        wordBtn.innerHTML = '⬇️ Word';
        wordBtn.title = '直接导出 Word 文档';
        wordBtn.onclick = () => {
            const data = extractContent();
            if (data) exportToWord(data.html);
            else alert('未找到题目');
        };

        const txtBtn = document.createElement('button');
        txtBtn.className = 'cx-btn warning';
        txtBtn.style.flex = '1'; // 均分宽度
        txtBtn.style.padding = '8px 5px';
        txtBtn.innerHTML = '⬇️ TXT';
        txtBtn.title = '直接导出 TXT 文件';
        txtBtn.onclick = () => {
            const data = extractContent();
            if (data) exportToTxt(data.text);
            else alert('未找到题目');
        };

        downloadGroup.appendChild(wordBtn);
        downloadGroup.appendChild(txtBtn);

        toolPanel.appendChild(mainBtn);
        toolPanel.appendChild(downloadGroup);
        document.body.appendChild(toolPanel);
    }

    // 延时加载，确保页面元素特别是iframe加载完成
    setTimeout(() => {
        if (document.readyState === 'complete') {
            init();
        } else {
            window.addEventListener('load', init);
        }
    }, 2000); // 稍微延长等待时间


})();