// ==UserScript==
// @name         HLS SSAI Ad Cleaner (Mobile Preview)
// @name:zh-CN   HLS SSAI 广告过滤工具 (移动端预览版)
// @namespace    hls-ssai-ad-cleaner-preview
// @version      3.0-preview
// @description      针对移动端 Edge 优化的 HLS 净化预览版。修正了过滤逻辑并增强了标签保留，解决了移动端内核加载失败的问题。
// @description:zh-CN 针对移动端 Edge 优化的 HLS 净化预览版。修正了过滤逻辑并增强了标签保留，解决了移动端内核加载失败的问题。
// @author       Gavin Newsom
// @match        *://*/*
// @grant        none
// @run-at       document-start
// @license      MIT
// @downloadURL https://update.greasyfork.icu/scripts/576352/HLS%20SSAI%20Ad%20Cleaner%20%28Mobile%20Preview%29.user.js
// @updateURL https://update.greasyfork.icu/scripts/576352/HLS%20SSAI%20Ad%20Cleaner%20%28Mobile%20Preview%29.meta.js
// ==/UserScript==

(function () {
    'use strict';

    const LOG_PREFIX = '[AdCleaner-Preview]';
    const oldXhrOpen = XMLHttpRequest.prototype.open;
    const oldFetch = window.fetch;

    /**
     * 深度净化核心逻辑 (移动端稳定版)
     */
    function getPurifiedUrlSync(url) {
        if (!url || typeof url !== 'string' || url.startsWith('blob:') || url.startsWith('data:')) return url;
        if (!url.includes('m3u8')) return url;

        try {
            const xhr = new XMLHttpRequest();
            xhr.isInternalRequest = true;
            // 使用同步请求获取内容
            oldXhrOpen.apply(xhr, ['GET', url, false]);
            xhr.send();

            if (xhr.status === 200) {
                let content = xhr.responseText;
                const lines = content.split('\n');
                const newLines = [];
                const isMaster = content.includes('#EXT-X-STREAM-INF');
                const hasAds = content.includes('#EXT-X-DISCONTINUITY');

                if (isMaster) {
                    for (let line of lines) {
                        let t = line.trim();
                        if (t && !t.startsWith('#')) {
                            const absUrl = new URL(t, url).href;
                            newLines.push(getPurifiedUrlSync(absUrl));
                        } else {
                            newLines.push(line);
                        }
                    }
                } else if (hasAds) {
                    let count = 0, keep = true;
                    for (let line of lines) {
                        let t = line.trim();
                        if (!t) continue;

                        if (t.startsWith('#EXT-X-DISCONTINUITY')) {
                            count++;
                            // 修正后的逻辑：偶数区间(0, 2, 4...)通常是正片
                            keep = (count % 2 === 0);
                            newLines.push(t);
                            continue;
                        }

                        // 关键：保留所有非片段配置标签，确保索引文件格式完整
                        if (t.startsWith('#EXT-X-') && !t.startsWith('#EXTINF')) {
                            newLines.push(t);
                            continue;
                        }

                        // 处理视频片段信息
                        if (keep || t.startsWith('#EXTM3U') || t.startsWith('#EXT-X-ENDLIST')) {
                            if (!t.startsWith('#') && !t.startsWith('http')) {
                                t = new URL(t, url).href;
                            }
                            newLines.push(t);
                        }
                    }
                } else {
                    // 无广告时，仅执行绝对路径转换
                    for (let line of lines) {
                        let t = line.trim();
                        if (t && !t.startsWith('#') && !t.startsWith('http')) {
                            newLines.push(new URL(t, url).href);
                        } else {
                            newLines.push(line);
                        }
                    }
                }

                const finalContent = newLines.join('\n');
                const finalBlob = URL.createObjectURL(new Blob([finalContent], { type: 'application/vnd.apple.mpegurl' }));
                
                // 打印净化对比日志
                if (content.length !== finalContent.length) {
                    console.log(`${LOG_PREFIX} 净化成功: ${url.split('/').pop()} (${content.length} -> ${finalContent.length} bytes)`);
                }
                
                return finalBlob;
            }
        } catch (e) {
            console.error(`${LOG_PREFIX} 净化过程中发生异常:`, e);
        }
        return url;
    }

    // 劫持 XHR Open
    XMLHttpRequest.prototype.open = function (m, url, ...args) {
        if (!this.isInternalRequest && typeof url === 'string' && url.includes('m3u8')) {
            url = getPurifiedUrlSync(url);
        }
        return oldXhrOpen.apply(this, [m, url, ...args]);
    };

    // 劫持 Fetch API
    window.fetch = function (input, init) {
        let url = (input instanceof Request) ? input.url : String(input);
        if (!init?.isInternal && url.includes('m3u8') && !url.startsWith('blob:')) {
            url = getPurifiedUrlSync(url);
            input = (input instanceof Request) ? new Request(url, input) : url;
        }
        return oldFetch(input, init);
    };

    // 劫持 HTMLMediaElement.src 及其子元素
    const hijackProperty = (proto, prop) => {
        const desc = Object.getOwnPropertyDescriptor(proto, prop);
        if (!desc) return;
        Object.defineProperty(proto, prop, {
            get: function () { return desc.get.call(this); },
            set: function (val) {
                if (val && typeof val === 'string' && val.includes('m3u8') && !val.startsWith('blob:')) {
                    val = getPurifiedUrlSync(val);
                }
                return desc.set.call(this, val);
            }
        });
    };

    hijackProperty(HTMLMediaElement.prototype, 'src');
    if (window.HTMLSourceElement) hijackProperty(HTMLSourceElement.prototype, 'src');

    console.log(`${LOG_PREFIX} 移动端预览版(3.0)已就绪`);
})();