// ==UserScript==
// @name         TMall Video URL Sniffer
// @namespace    https://scriptcat.org/zh-CN/users/161051
// @version      1.0
// @description  拦截天猫视频的真实 URL（支持 XHR/fetch/video.src）
// @author       MYZ
// @match        https://detail.tmall.com/*
// @grant        unsafeWindow
// @grant        GM_download
// @run-at       document-start
// ==/UserScript==

(function() {
    'use strict';

    // 存储已发现的视频 URL，避免重复添加按钮
    const foundUrls = new Set();

    // 1. 拦截 XMLHttpRequest
    const originalXHR = unsafeWindow.XMLHttpRequest;
    unsafeWindow.XMLHttpRequest = function() {
        const xhr = new originalXHR();
        const originalOpen = xhr.open;
        xhr.open = function(method, url) {
            if (isVideoUrl(url)) {
                console.log('[XHR] ======================= 发现视频 URL:', url);
                handleVideoUrl(url);
            }
            originalOpen.apply(this, arguments);
        };
        return xhr;
    };

    // 2. 拦截 fetch 请求
    const originalFetch = unsafeWindow.fetch;
    unsafeWindow.fetch = function(input, init) {
        const url = typeof input === 'string' ? input : input.url;
        if (isVideoUrl(url)) {
            console.log('[Fetch] =======================  发现视频 URL:', url);
            handleVideoUrl(url);
        }
        return originalFetch.apply(this, arguments);
    };

    // 3. 监听 <video> 标签的 src 变化
    const observer = new MutationObserver(mutations => {
        mutations.forEach(mutation => {
            mutation.addedNodes.forEach(node => {
                if (node.nodeName === 'VIDEO') {
                    const video = node;
                    if (isVideoUrl(video.src)) {
                        console.log('[Video] =======================  发现视频 URL:', video.src);
                        handleVideoUrl(video.src);
                    }
                    // 监听后续 src 变化
                    new MutationObserver((mutations, obs) => {
                        if (isVideoUrl(video.src)) {
                            console.log('[Video] =======================  视频 URL 更新:', video.src);
                            handleVideoUrl(video.src);
                        }
                    }).observe(video, { attributes: true, attributeFilter: ['src'] });
                }
            });
        });
    });
    observer.observe(document, { childList: true, subtree: true });

    // 判断是否是视频 URL
    function isVideoUrl(url) {
        return url && (url.includes('.mp4') || url.includes('.m3u8') || url.includes('.flv'));
    }

    // 处理视频 URL（添加下载按钮）
    function handleVideoUrl(url) {
        if (foundUrls.has(url)) return;
        foundUrls.add(url);

        const btnId = 'tmall-video-download-btn-' + Array.from(foundUrls).length;
        if (document.getElementById(btnId)) return;

        const btn = document.createElement('button');
        btn.id = btnId;
        btn.textContent = '下载视频 (' + new URL(url).pathname.split('/').pop() + ')';
        btn.style.position = 'fixed';
        btn.style.bottom = (20 + (Array.from(foundUrls).length - 1) * 50) + 'px';
        btn.style.right = '20px';
        btn.style.zIndex = '99999';
        btn.style.padding = '10px 15px';
        btn.style.background = '#FF5500';
        btn.style.color = 'white';
        btn.style.border = 'none';
        btn.style.borderRadius = '4px';
        btn.style.cursor = 'pointer';
        btn.style.fontFamily = 'Arial, sans-serif';
        btn.style.boxShadow = '0 2px 8px rgba(0,0,0,0.2)';

        btn.onclick = async () => {
          try {
              await navigator.clipboard.writeText(url);
              const originalText = btn.textContent;
              btn.textContent = '已复制到剪贴板!';
              setTimeout(() => {
                  btn.textContent = originalText;
              }, 2000);
          } catch (err) {
              console.error('Failed to copy URL: ', err);
              btn.textContent = '复制失败!';
              setTimeout(() => {
                  btn.textContent = originalText;
              }, 2000);
          }
        };

        document.body.appendChild(btn);
    }
})();