// ==UserScript==
// @name         弟子小说下载助手
// @namespace    http://tampermonkey.net/
// @version      2025.3.7
// @description  自动下载小说内容（带进度条版）
// @author       Your Name
// @match        *://www.dizishu.cc/b/*
// @grant        GM_xmlhttpRequest
// @grant        GM_download
// @grant        GM_setValue
// @grant        GM_getValue
// @connect      dizishu.cc
// ==/UserScript==

(function() {
    'use strict';

    const USER_AGENTS = [
        'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36',
        'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36',
        'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36'
    ];

    // 进度条容器
    const progressBar = document.createElement('div');
    progressBar.style = `
        position: fixed;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
        background: white;
        padding: 20px;
        border-radius: 8px;
        box-shadow: 0 0 10px rgba(0,0,0,0.2);
        z-index: 99999;
        display: none;
    `;

    const progressText = document.createElement('div');
    progressText.style.marginBottom = '10px';
    
    const barContainer = document.createElement('div');
    barContainer.style = `
        width: 300px;
        height: 20px;
        background: #eee;
        border-radius: 10px;
        overflow: hidden;
    `;

    const bar = document.createElement('div');
    bar.style = `
        width: 0%;
        height: 100%;
        background: #4CAF50;
        transition: width 0.3s ease;
    `;

    barContainer.appendChild(bar);
    progressBar.appendChild(progressText);
    progressBar.appendChild(barContainer);
    document.body.appendChild(progressBar);

    function getRandomUserAgent() {
        return USER_AGENTS[Math.floor(Math.random() * USER_AGENTS.length)];
    }

    function decodeContent(buffer) {
        const encodings = ['utf-8', 'gbk', 'gb2312', 'big5', 'gb18030'];
        for (let enc of encodings) {
            try {
                const decoder = new TextDecoder(enc, {fatal: true});
                return decoder.decode(buffer);
            } catch(e) {}
        }
        return new TextDecoder('utf-8', {fatal: false}).decode(buffer);
    }

    async function fetchChapter(url, index) {
        return new Promise((resolve) => {
            GM_xmlhttpRequest({
                method: "GET",
                url: url,
                headers: {
                    "User-Agent": getRandomUserAgent(),
                    "Referer": window.location.href
                },
                responseType: "arraybuffer",
                onload: function(res) {
                    try {
                        const html = decodeContent(res.response);
                        const parser = new DOMParser();
                        const doc = parser.parseFromString(html, "text/html");

                        // 修改后的内容选择器
                        const title = doc.querySelector('.chaptername')?.textContent.trim();
                        const txtElement = doc.querySelector('#txt');

                        // 获取原始HTML内容处理换行
                        let content = txtElement?.innerHTML || '';

                        // 内容清洗
                        const cleaned = content
                            .replace(/<a\s[^>]*?href\s*=\s*["']\s*javascript:posterror\(\);\s*["'][^>]*>.*?<\/a>/gis, '')  // 新增：去除指定锚标签
                            .replace(/『如果章节错误.*?举报』/gs, '')
                            .replace(/<br\s*\/?>/gi, '\n')
                            .replace(/<\/p>|<div>/gi, '\n')
                            .replace(/&nbsp;/g, ' ')
                            .replace(/[ \t\u3000]{2,}/g, ' ')
                            .replace(/\n{3,}/g, '\n\n')
                            .trim();

                        resolve({index, title, content: cleaned});
                    } catch(e) {
                        resolve({index, error: true});
                    }
                },
                onerror: () => resolve({index, error: true})
            });
        });
    }

    async function startDownload() {
        
        // 显示进度条
        progressBar.style.display = 'block';
        bar.style.width = '0%';
        progressText.textContent = '准备中...';

        try {
            // 获取书籍信息
            const bookName = document.querySelector('h1').textContent.trim();
            // 获取第二个ul下的li a
            const bookChapterList = document.querySelector('.book-chapter-list');
            const secondUl = bookChapterList.querySelectorAll('ul')[1];
            const chapterLinks = Array.from(secondUl.querySelectorAll('li a'));
            
            // 创建章节队列
            const chapters = chapterLinks.map((a, index) => ({
                url: a.href,
                index: index + 1,
                completed: false
            }));

            // 并发控制
            const parallel = 5; // 降低并发数更稳定  注：只能往小了调，服务器会吃不消
            const total = chapters.length;
            let completed = 0;
            
            const results = [];
            for (let i = 0; i < total; i += parallel) {
                const batch = chapters.slice(i, i + parallel);
                const promises = batch.map(c => 
                    fetchChapter(c.url, c.index)
                        .then(res => {
                            completed++;
                            // 更新进度
                            const progress = Math.round((completed / total) * 100);
                            bar.style.width = `${progress}%`;
                            progressText.textContent = 
                                `下载中 ${completed}/${total} (${progress}%)`;
                            return res;
                        })
                );
                
                const batchResults = await Promise.all(promises);
                results.push(...batchResults);
                await new Promise(r => setTimeout(r, 500)); // 增加间隔
            }

            // 处理结果
            const validChapters = results
                .filter(r => !r.error && r.title)
                .sort((a, b) => a.index - b.index);

            // 生成内容
            const content = validChapters
                .map(r => `${r.title}\n\n${r.content}\n\n`)
                .join('');

            // 创建下载
            const blob = new Blob([content], {type: 'text/plain;charset=utf-8'});
            const url = URL.createObjectURL(blob);
            GM_download({
                url: url,
                name: `${bookName}.txt`,
                saveAs: true
            });

            progressText.textContent = '下载完成！';
            setTimeout(() => progressBar.style.display = 'none', 2000);
        } catch (e) {
            progressText.textContent = '下载失败，请刷新重试';
            console.error(e);
        }
    }

    // 添加下载按钮
    function addButton() {
        const btn = document.createElement('button');
        btn.style = `
            padding: 10px 20px 10px 20px;
            z-index: 9999;
            background: #4CAF50;
            color: white;
            border: none;
            border-radius: 4px;
            cursor: pointer;
        `;
        btn.textContent = '下载小说';
        btn.onclick = startDownload;

        // 假设这里有一个btn元素，将下载按钮添加到它下面
        document.querySelector('.btn').appendChild(btn);
    }

    setTimeout(addButton, 2000);
})();