// ==UserScript==
// @name         B站PCDN拦截器
// @namespace    lllbbbzzz
// @version      8.3.0
// @description  拦截B站PCDN视频源，主动替换为正规CDN。防止你成为PCDN节点
// @author       lllbbbzzz
// @icon         https://bsyimg.luoca.net/imgtc/20260321/3e2aea17a0f2fd3b44e0cf5effccc060.webp
// @match        *://*.bilibili.com/*
// @match        *://*.bilibili.tv/*
// @match        *://*.bilivideo.cn/*
// @run-at       document-start
// @grant        GM_registerMenuCommand
// @license      MIT
// ==/UserScript==

(function () {
    'use strict';

    const KEY = 'pcdn_killer_v8';
    let on = localStorage.getItem(KEY) !== '0';
    let cnt = 0;
    let toastTimer = null;

    // --- 检测规则 ---
    const RE_PCDN_HOST = /\.mcdn\.bilivideo\.cn|szbdyd\.com|cos\.bilibili\.com\/.*pcdn/i;
    const RE_PCDN_PATH = /xy\d+x\d+x\d+x\d+xy|\/pcdn\/|\/mcdn\//i;
    const RE_PRIVATE_IP = /^https?:\/\/(10\.|172\.(1[6-9]|2\d|3[01])\.|192\.168\.|127\.)/;
    const RE_SIGNAL = /p2p|pcdn|mcdn|webrtc|signal|stun|turn/i;
    const RE_ADS = /\/x\/web-interface\/wbi\/index|googleads|doubleclick|adsense|googlesyndication|adsrvr|adnxs|tracking\/pixel|beacon\/report/i;

    function isPCDN(u) {
        return u && (RE_PCDN_HOST.test(u) || RE_PCDN_PATH.test(u) || RE_PRIVATE_IP.test(u));
    }
    function isSeg(u) {
        return u && (/\/seg\//i.test(u) || /\d+-\d+\.(m4s|ts)(\?|$)/i.test(u));
    }
    function isSig(u) {
        return u && RE_SIGNAL.test(u);
    }
    function isAd(u) {
        return u && RE_ADS.test(u);
    }

    // --- Toast 通知 ---
    function showToast() {
        if (toastTimer) clearTimeout(toastTimer);
        let el = document.getElementById('pcdn-toast');
        if (!el) {
            el = document.createElement('div');
            el.id = 'pcdn-toast';
            el.style.cssText = 'position:fixed;bottom:16px;right:16px;padding:6px 14px;border-radius:8px;font:600 12px/1.6 -apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:#fff;z-index:2147483647;pointer-events:none;transition:opacity .4s;box-shadow:0 2px 8px rgba(0,0,0,.3)';
            (document.body || document.documentElement).appendChild(el);
        }
        const bg = on ? '#00a843' : '#c62828';
        const text = on ? 'PCDN拦截 ON' + (cnt > 0 ? ' · ' + cnt : '') : 'PCDN拦截 OFF';
        el.style.cssText = el.style.cssText.replace(/background:[^;]+/, '') + ';background:' + bg;
        el.textContent = text;
        el.style.opacity = '1';
        toastTimer = setTimeout(function () { el.style.opacity = '0'; }, 2500);
    }

    // --- WebRTC ---
    (function () {
        if (!window.RTCPeerConnection) return;
        const Orig = window.RTCPeerConnection;
        window.RTCPeerConnection = function (cfg, cns) {
            if (on && cfg && cfg.iceServers) {
                const urls = [];
                cfg.iceServers.forEach(function (s) {
                    if (s.urls) urls.push(...(Array.isArray(s.urls) ? s.urls : [s.urls]));
                });
                if (urls.some(function (u) { return isPCDN(u) || isSig(u); })) {
                    cnt++;
                    return new Orig({ iceServers: [{ urls: 'stun:0.0.0.0' }] });
                }
            }
            return new Orig(cfg, cns);
        };
        window.RTCPeerConnection.prototype = Orig.prototype;
        for (const k in Orig) {
            if (typeof Orig[k] === 'function') window.RTCPeerConnection[k] = Orig[k];
        }
    })();

    // --- WebSocket ---
    (function () {
        const Orig = window.WebSocket;
        window.WebSocket = function (url, proto) {
            if (on && isSig(url)) {
                cnt++;
                const ws = proto !== undefined ? new Orig(url, proto) : new Orig(url);
                setTimeout(function () { try { ws.close(); } catch (e) {} }, 0);
                return ws;
            }
            return proto !== undefined ? new Orig(url, proto) : new Orig(url);
        };
        window.WebSocket.prototype = Orig.prototype;
    })();

    // --- ServiceWorker ---
    (function () {
        if (!navigator.serviceWorker) return;
        const orig = navigator.serviceWorker.register;
        navigator.serviceWorker.register = function (url) {
            if (on && /p2p|pcdn|mcdn|sw-proxy|cdn-worker/i.test(url || '')) {
                cnt++;
                return Promise.reject(new DOMException('blocked', 'AbortError'));
            }
            return orig.apply(this, arguments);
        };
    })();

    // --- SharedWorker ---
    (function () {
        if (!window.SharedWorker) return;
        const Orig = window.SharedWorker;
        window.SharedWorker = function (url, opt) {
            if (on && /p2p|pcdn|mcdn/i.test(url || '')) {
                cnt++;
                return { port: { start: function () {} } };
            }
            return new Orig(url, opt);
        };
        window.SharedWorker.prototype = Orig.prototype;
    })();

    // --- Worker ---
    (function () {
        const Orig = window.Worker;
        window.Worker = function (url, opt) {
            if (on && /p2p|pcdn|mcdn/i.test(url || '')) {
                cnt++;
                return { postMessage: function () {}, terminate: function () {}, addEventListener: function () {} };
            }
            return new Orig(url, opt);
        };
        window.Worker.prototype = Orig.prototype;
    })();

    // --- sendBeacon ---
    (function () {
        if (!navigator.sendBeacon) return;
        const orig = navigator.sendBeacon;
        navigator.sendBeacon = function (url) {
            if (on && isSig(url)) { cnt++; return true; }
            return orig.apply(this, arguments);
        };
    })();

    // --- EventSource ---
    (function () {
        if (!window.EventSource) return;
        const Orig = window.EventSource;
        window.EventSource = function (url, opt) {
            if (on && isSig(url)) {
                cnt++;
                return { close: function () {}, addEventListener: function () {}, readyState: 2 };
            }
            return new Orig(url, opt);
        };
        window.EventSource.prototype = Orig.prototype;
    })();

    // --- CDN 替换 ---
    function replaceCDN(json) {
        if (!on || !json || !json.dash) return json;

        const good = [];
        ['video', 'audio'].forEach(function (t) {
            if (!json.dash[t]) return;
            json.dash[t].forEach(function (s) {
                if (s.base_url && !isPCDN(s.base_url)) good.push(s.base_url);
                (s.backup_url || []).forEach(function (u) {
                    if (!isPCDN(u)) good.push(u);
                });
            });
        });
        if (!good.length) return json;

        const hosts = [];
        good.forEach(function (u) {
            try {
                const h = new URL(u, location.origin).host;
                if (hosts.indexOf(h) < 0) hosts.push(h);
            } catch (e) {}
        });
        if (!hosts.length) return json;

        function genUrl(base, host) {
            try { return new URL(base).href.replace(/^[a-z]+:\/\/[^/]+/, 'https://' + host); }
            catch (e) { return 'https://' + host + (base || ''); }
        }

        let dirty = false;
        ['video', 'audio'].forEach(function (t) {
            if (!json.dash[t]) return;
            json.dash[t].forEach(function (s) {
                const bk = [];
                (s.backup_url || []).forEach(function (u) {
                    if (!isPCDN(u)) bk.push(u); else dirty = true;
                });

                if (isPCDN(s.base_url)) {
                    s.base_url = bk.length ? bk[0] : genUrl(s.base_url, hosts[0]);
                    dirty = true;
                }

                while (bk.length < 3 && hosts.length) {
                    bk.push(genUrl(s.base_url, hosts[bk.length % hosts.length]));
                }
                s.backup_url = bk;
            });
        });

        if (dirty) cnt++;
        return json;
    }

    // --- fetch hook ---
    const _fetch = window.fetch;
    window.fetch = function (input) {
        const url = typeof input === 'string' ? input : (input && input.url) || '';

        if (on && isPCDN(url) && isSeg(url)) { cnt++; return Promise.reject(new DOMException('blocked', 'AbortError')); }
        if (on && isAd(url)) { cnt++; return Promise.reject(new DOMException('blocked', 'AbortError')); }
        if (on && isSig(url)) { cnt++; return Promise.reject(new DOMException('blocked', 'AbortError')); }

        return _fetch.apply(this, arguments).then(function (res) {
            if (!on || !/\/playurl/i.test(url)) return res;
            return res.clone().text().then(function (text) {
                try {
                    const j = JSON.parse(text);
                    const r = replaceCDN(j);
                    if (r === j) return res;
                    return new Response(JSON.stringify(r), {
                        status: res.status, statusText: res.statusText, headers: res.headers
                    });
                } catch (e) { return res; }
            });
        });
    };

    // --- XHR hook ---
    const _open = XMLHttpRequest.prototype.open;
    const _send = XMLHttpRequest.prototype.send;
    const _rtd = Object.getOwnPropertyDescriptor(XMLHttpRequest.prototype, 'responseText');

    XMLHttpRequest.prototype.open = function (m, u) {
        this._u = u;
        this._play = /\/playurl/i.test(u);
        return _open.apply(this, arguments);
    };

    XMLHttpRequest.prototype.send = function () {
        const self = this;
        if (on && isPCDN(this._u) && isSeg(this._u)) { cnt++; try { this.abort(); } catch (e) {} return; }
        if (on && isAd(this._u)) { cnt++; try { this.abort(); } catch (e) {} return; }
        if (on && this._play) {
            this.addEventListener('readystatechange', function () {
                if (self.readyState !== 4 || self.status !== 200) return;
                try {
                    const t = _rtd ? _rtd.get.call(self) : self.responseText;
                    const j = JSON.parse(t);
                    const r = replaceCDN(j);
                    if (r === j) return;
                    const out = JSON.stringify(r);
                    if (_rtd) Object.defineProperty(self, 'responseText', { value: out, writable: true, configurable: true });
                    Object.defineProperty(self, 'response', { value: out, writable: true, configurable: true });
                } catch (e) {}
            });
        }
        return _send.apply(this, arguments);
    };

    // --- DOM 优化 ---
    const deferCSS = document.createElement('style');
    deferCSS.textContent = '#comment,.bili-comment-container,.review-list,.bpx-player-ending,.video-card-list,.rec-list,.floor-single-card{content-visibility:auto;contain-intrinsic-size:1px 600px}';
    (document.head || document.documentElement).appendChild(deferCSS);

    // --- 初始化 ---
    GM_registerMenuCommand('PCDN拦截: ' + (on ? '已开启' : '已关闭') + ' (点击切换)', function () {
        on = !on;
        if (!on) cnt = 0;
        localStorage.setItem(KEY, on ? '1' : '0');
        showToast();
    });

    if (document.body) {
        showToast();
    } else {
        document.addEventListener('DOMContentLoaded', showToast);
    }

})();