// ==UserScript==
// @name         DeepSeek 纯净导出（带对话名称版 v3.1）
// @namespace    https://chat.deepseek.com/
// @version      3.1
// @description  直接解析 DOM 将对话还原为 Markdown，文件名自动附带对话名称
// @match        https://chat.deepseek.com/*
// @grant        none
// @require      https://cdn.jsdelivr.net/npm/turndown@7.1.2/dist/turndown.min.js
// @require      https://cdn.jsdelivr.net/npm/turndown-plugin-gfm@1.0.2/dist/turndown-plugin-gfm.min.js
// @run-at       document-end
// @license MIT
// ==/UserScript==

(function () {
    'use strict';
    const DEBUG = true;
    const log = (...args) => { if (DEBUG) console.log('[DS-Export]', ...args); };

    /* ===== 初始化 Turndown 引擎 ===== */
    const turndownService = new TurndownService({
        headingStyle: 'atx',
        codeBlockStyle: 'fenced',
        bulletListMarker: '-'
    });
    
    // 启用 GFM 插件（支持表格、删除线等）
    if (typeof turndownPluginGfm !== 'undefined') {
        turndownService.use(turndownPluginGfm.tables);
        turndownService.use(turndownPluginGfm.strikethrough);
    }

    // 自定义规则：处理代码块和 Mermaid
    turndownService.addRule('codeBlock', {
        filter: function (node) {
            return node.nodeName === 'PRE' && node.querySelector('code');
        },
        replacement: function (content, node) {
            const codeNode = node.querySelector('code');
            let code = codeNode.textContent;
            let lang = '';
            
            const className = codeNode.className || '';
            const langMatch = className.match(/language-(\w+)/);
            if (langMatch) lang = langMatch[1];
            
            if (className.includes('mermaid') || node.querySelector('.mermaid')) {
                lang = 'mermaid';
            }
            return '\n```' + lang + '\n' + code + '\n```\n';
        }
    });

    // 自定义规则：处理已经被渲染成 SVG 的 Mermaid
    turndownService.addRule('mermaidSvg', {
        filter: function (node) {
            return node.nodeName === 'SVG' || (node.nodeName === 'DIV' && node.querySelector('svg'));
        },
        replacement: function (content, node) {
            if (node.getAttribute('data-code')) {
                return '\n```mermaid\n' + node.getAttribute('data-code') + '\n```\n';
            }
            if (node.closest('pre')) return '';
            return '\n```mermaid\n%% Mermaid 图表（源码未在DOM中保留）\n```\n';
        }
    });

    /* ===== 工具函数 ===== */
    
    // 获取对话名称并清理非法字符
    function getChatTitle() {
        // 优先从浏览器标题获取（最稳定）
        let title = document.title.replace(/ - DeepSeek$/i, '').trim();
        
        // 如果标题为空或者是默认的，尝试从页面顶部找
        if (!title || title === 'DeepSeek') {
            const titleEl = document.querySelector('.header-title, [class*="title"]');
            if (titleEl && titleEl.textContent.trim()) {
                title = titleEl.textContent.trim();
            }
        }
        
        // 兜底
        if (!title) title = '对话';
        
        // 清理 Windows/Mac 不支持的非法文件名字符，并限制长度
        return title.replace(/[\\/:*?"<>|]/g, '_').slice(0, 50);
    }

    function download(filename, content) {
        const blob = new Blob([content], { type: 'text/markdown;charset=utf-8' });
        const url = URL.createObjectURL(blob);
        const a = document.createElement('a'); a.href = url; a.download = filename;
        document.body.appendChild(a); a.click(); document.body.removeChild(a);
        URL.revokeObjectURL(url);
    }
    
    function timestamp() {
        const d = new Date(); const p = n => String(n).padStart(2, '0');
        return `${d.getFullYear()}${p(d.getMonth()+1)}${p(d.getDate())}_${p(d.getHours())}${p(d.getMinutes())}${p(d.getSeconds())}`;
    }

    /* ===== 注入按钮 ===== */
    function injectButtons() {
        const mdBlocks = document.querySelectorAll('.ds-markdown');
        if (mdBlocks.length === 0) return;

        mdBlocks.forEach((md, index) => {
            if (md.dataset.dsExportInjected) return;
            md.dataset.dsExportInjected = '1';

            const btnWrapper = document.createElement('div');
            btnWrapper.style.cssText = 'display: flex; gap: 8px; margin-top: 10px; margin-bottom: 4px;';

            // 1. 导出单条 AI 回复
            const singleBtn = document.createElement('button');
            singleBtn.textContent = '导出本条';
            singleBtn.style.cssText = 'padding: 4px 10px; font-size: 12px; background: #f0f4ff; border: 1px solid #d0d9ff; color: #4d6bfe; border-radius: 6px; cursor: pointer; transition: all 0.2s;';
            singleBtn.onmouseover = () => singleBtn.style.background = '#e8eeff';
            singleBtn.onmouseout = () => singleBtn.style.background = '#f0f4ff';
            singleBtn.onclick = (e) => {
                e.stopPropagation();
                const mdText = turndownService.turndown(md.innerHTML);
                // 文件名加入名称：DeepSeek_名称_AI_时间.md
                const title = getChatTitle();
                download(`DeepSeek_${title}_AI_${timestamp()}.md`, mdText);
            };
            btnWrapper.appendChild(singleBtn);

            // 2. 导出本轮（向上寻找用户消息）
            const roundBtn = document.createElement('button');
            roundBtn.textContent = '导出本轮';
            roundBtn.style.cssText = 'padding: 4px 10px; font-size: 12px; background: #4d6bfe; border: none; color: #fff; border-radius: 6px; cursor: pointer;';
            roundBtn.onclick = (e) => {
                e.stopPropagation();
                let userMd = '';
                
                let parent = md.parentElement;
                for (let i = 0; i < 6; i++) {
                    if (!parent) break;
                    const textNodes = [...parent.querySelectorAll('div, p')].filter(n => 
                        !n.closest('.ds-markdown') && 
                        n.textContent.trim().length > 0 && 
                        n.children.length === 0
                    );
                    if (textNodes.length > 0) {
                        const potentialUserText = textNodes[0].textContent.trim();
                        if (potentialUserText && potentialUserText.length < 2000) {
                            userMd = potentialUserText;
                            break;
                        }
                    }
                    parent = parent.parentElement;
                }

                const aiMd = turndownService.turndown(md.innerHTML);
                const finalContent = userMd ? (userMd + '\n\n' + aiMd) : aiMd;
                
                // 文件名加入名称：DeepSeek_名称_本轮_时间.md
                const title = getChatTitle();
                download(`DeepSeek_${title}_本轮_${timestamp()}.md`, finalContent);
            };
            btnWrapper.appendChild(roundBtn);

            md.parentElement.insertBefore(btnWrapper, md.nextSibling);
        });
    }

    /* ===== 监听 DOM 与初始化 ===== */
    function start() {
        injectButtons();
        setInterval(injectButtons, 2000);
        
        const observer = new MutationObserver(() => {
            injectButtons();
        });
        observer.observe(document.body, { childList: true, subtree: true });
    }

    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', start);
    } else {
        start();
    }
})();