// ==UserScript==
// @name         UC网盘免客户端下载
// @namespace    http://tampermonkey.net/
// @version      250911
// @description  UC网盘分享链接免客户端下载，例外谷歌网盘域名
// @author       Magiclyan
// @copyright    M
// @license      GPL-3.0 License
// @match        *://*/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // 排除Google Drive的正则表达式
    const googleDriveRegex = /https?:\/\/(www\.)?drive\.google\.com/gi;
    // 匹配其他drive相关域名的正则表达式
    const driveRegex = /https?:\/\/(www\.)?drive\.(?!google\.com)/gi;
    const driveDomainRegex = /^https?:\/\/(www\.)?drive\.(?!google\.com)/i;

    // 检查是否为Google Drive链接
    function isGoogleDrive(url) {
        return googleDriveRegex.test(url);
    }

    // 处理当前页面URL，如果是drive域名(非Google)则替换为fast并刷新
    function handleCurrentPageUrl() {
        // 如果是Google Drive则不处理
        if (isGoogleDrive(window.location.href)) {
            return;
        }
        
        if (driveDomainRegex.test(window.location.href)) {
            const newUrl = window.location.href.replace(driveRegex, 'https://fast.');
            // 避免无限循环刷新
            if (newUrl !== window.location.href) {
                window.location.href = newUrl;
            }
        }
    }

    // 替换页面中所有链接的函数（排除Google Drive）
    function replaceLinks() {
        // 替换普通链接
        const links = document.getElementsByTagName('a');
        for (let link of links) {
            // 跳过Google Drive链接
            if (link.href && isGoogleDrive(link.href)) {
                continue;
            }
            
            if (link.href && driveRegex.test(link.href)) {
                link.href = link.href.replace(driveRegex, 'https://fast.');
                // 添加视觉提示，标记已替换的链接
                link.classList.add('uc-drive-replaced');
                link.style.color = '#2196F3';
            }
        }

        // 替换iframe中的链接（如果有访问权限）
        const iframes = document.getElementsByTagName('iframe');
        for (let iframe of iframes) {
            try {
                const iframeDoc = iframe.contentDocument || iframe.contentWindow.document;
                const iframeLinks = iframeDoc.getElementsByTagName('a');
                for (let link of iframeLinks) {
                    // 跳过Google Drive链接
                    if (link.href && isGoogleDrive(link.href)) {
                        continue;
                    }
                    
                    if (link.href && driveRegex.test(link.href)) {
                        link.href = link.href.replace(driveRegex, 'https://fast.');
                    }
                }
            } catch (e) {
                // 跨域iframe无法访问，忽略错误
                continue;
            }
        }
        
        // 处理文本中的链接（仅替换纯文本节点，排除Google Drive）
        function replaceInTextNodes(node) {
            if (node.nodeType === Node.TEXT_NODE) {
                // 跳过包含Google Drive的文本
                if (googleDriveRegex.test(node.textContent)) {
                    return;
                }
                
                if (driveRegex.test(node.textContent)) {
                    node.textContent = node.textContent.replace(driveRegex, 'https://fast.');
                }
            } else if (node.nodeType === Node.ELEMENT_NODE && 
                      !['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA'].includes(node.tagName)) {
                // 跳过可能影响功能的标签
                for (let child of node.childNodes) {
                    replaceInTextNodes(child);
                }
            }
        }
        
        replaceInTextNodes(document.body);
    }

    // 初始化执行
    handleCurrentPageUrl();
    replaceLinks();

    // 页面加载完成后再次执行
    window.addEventListener('load', replaceLinks);

    // 优化动态内容监听，减少性能消耗
    let observer = new MutationObserver((mutations) => {
        // 检查是否有实际需要处理的变化
        const needUpdate = mutations.some(mutation => 
            mutation.type === 'childList' || 
            (mutation.type === 'characterData' && driveRegex.test(mutation.target.textContent) && 
             !googleDriveRegex.test(mutation.target.textContent))
        );
        
        if (needUpdate) {
            clearTimeout(window.replaceLinksTimeout);
            window.replaceLinksTimeout = setTimeout(replaceLinks, 300);
        }
    });

    // 观察文档变化，限制观察范围以提高性能
    observer.observe(document.body, {
        childList: true,
        subtree: true,
        characterData: true,
        attributes: true,
        attributeFilter: ['href'] // 只观察href属性变化
    });

    // 清理函数
    window.addEventListener('unload', () => {
        observer.disconnect();
        clearTimeout(window.replaceLinksTimeout);
    });
})();