// ==UserScript==
// @name         anti-rickroll
// @namespace    http://tampermonkey.net/
// @version      11.4
// @description  修复了一些已知问题
// @author       dext
// @match        *://*/*
// @grant        GM_xmlhttpRequest
// @grant        GM_addStyle
// @connect      anti-rickroll.dext.top
// @run-at       document-start
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';

    const API_ENDPOINT = "https://anti-rickroll.dext.top";
    const cache = new Map();
    const queue = [];
    let activeRequests = 0;
    const MAX_CONCURRENT = 3;

    if (window.location.hash.includes('force-pass')) return;

    GM_addStyle(`
        #rick-breaker-overlay { position: fixed; top:0; left:0; width:100%; height:100%; background:rgba(0,0,0,0.95); z-index:2147483647; display:flex; justify-content:center; align-items:center; backdrop-filter:blur(20px); }
        .rick-card { background:#fff; padding:40px; border-radius:24px; width:360px; text-align:center; border:6px solid #ff4444; box-shadow: 0 20px 60px rgba(0,0,0,0.6); font-family: sans-serif; }
        .rick-btn { padding:15px; border-radius:12px; cursor:pointer; border:none; font-weight:bold; width:100%; margin-top:15px; font-size:16px; transition: transform 0.1s; }
        .rick-btn:active { transform: scale(0.98); }
        .btn-safe { background:#eee; color:#333; }
        .btn-danger { background:#ff4444; color:#fff; font-size:11px; opacity:0.6; }
        a.rickroll-danger { outline: 2px dashed #ff4444 !important; outline-offset: 2px; }
    `);

    function recallToOrigin() {
        const referrer = document.referrer;
        if (referrer && !referrer.includes(window.location.hostname)) {
            window.location.replace(referrer);
        } else if (window.history.length > 1) {
            window.history.go(-window.history.length + 1);
            setTimeout(() => { if(!document.hidden) window.close(); }, 500);
        } else {
            window.close();
        }
    }

    function silencePage() {
        document.querySelectorAll('video, audio').forEach(m => { m.pause(); m.muted = true; });
    }

    function renderOverlay(title, url, isIncoming = false) {
        if (document.getElementById('rick-breaker-overlay')) return;
        const silencer = setInterval(silencePage, 200);

        const overlay = document.createElement('div');
        overlay.id = 'rick-breaker-overlay';
        overlay.innerHTML = `
            <div class="rick-card">
                <div style="font-size:60px">🛑</div>
                <h2 style="color:#ff4444; margin:15px 0;">${title}</h2>
                <p style="color:#444; font-size:15px; line-height:1.5;"><br>此路径通往 <b>Rickroll</b> 陷阱。</p>
                <button class="rick-btn btn-safe" id="r-back">安全溯源回退</button>
                <button class="rick-btn btn-danger" id="r-go">我已知晓风险，非要看</button>
            </div>`;

        (document.body || document.documentElement).appendChild(overlay);

        document.getElementById('r-back').onclick = () => {
            clearInterval(silencer);
            recallToOrigin();
        };

        document.getElementById('r-go').onclick = () => {
            clearInterval(silencer);
            overlay.remove();
            // 加上强制通行证并重新加载
            window.location.replace(url + (url.includes('#') ? '&' : '#') + 'force-pass');
        };
    }

    function checkIncoming() {
        const url = window.location.href;
        if (url.length < 25 || /google|baidu|bing/.test(window.location.hostname)) return;

        GM_xmlhttpRequest({
            method: "POST",
            url: API_ENDPOINT,
            data: JSON.stringify({ url }),
            headers: { "Content-Type": "application/json" },
            onload: (res) => {
                try {
                    const data = JSON.parse(res.responseText);
                    if (data.isRickroll) {
                        window.stop();
                        silencePage();
                        renderOverlay("入境链路拦截", url, true);
                    }
                } catch (e) {}
            }
        });
    }

    function isInternalLink(url) {
        try {
            const target = new URL(url);
            return target.protocol === window.location.protocol && target.hostname === window.location.hostname;
        } catch (e) { return true; }
    }

    function getRealUrl(url) {
        try {
            const u = new URL(url);
            if (u.hostname.includes('google.com') && u.searchParams.has('q')) return u.searchParams.get('q');
            if (u.hostname.includes('baidu.com') && u.searchParams.has('url')) return u.searchParams.get('url');
        } catch (e) {}
        return url;
    }

    function processQueue() {
        if (queue.length === 0 || activeRequests >= MAX_CONCURRENT) return;
        const url = queue.shift();
        activeRequests++;
        GM_xmlhttpRequest({
            method: "POST",
            url: API_ENDPOINT,
            data: JSON.stringify({ url }),
            headers: { "Content-Type": "application/json" },
            onload: (res) => {
                try {
                    const data = JSON.parse(res.responseText);
                    cache.set(url, data.isRickroll);
                    if (data.isRickroll) {
                        document.querySelectorAll('a').forEach(a => { if(getRealUrl(a.href) === url) a.classList.add('rickroll-danger'); });
                    }
                } catch (e) {}
                activeRequests--; processQueue();
            },
            onerror: () => { activeRequests--; processQueue(); }
        });
    }

    function scanPage() {
        const EXCLUDE = /\.(jpg|jpeg|png|gif|css|js|woff|zip|pdf|mp4)($|\?)/i;
        document.querySelectorAll('a[href]').forEach(a => {
            const realUrl = getRealUrl(a.href);
            if (!realUrl.startsWith('http') || isInternalLink(realUrl) || EXCLUDE.test(realUrl) || cache.has(realUrl)) return;
            cache.set(realUrl, 'pending');
            queue.push(realUrl);
        });
        processQueue();
    }

    window.addEventListener('click', function(e) {
        const a = e.target.closest('a');
        if (!a || !a.href || !a.href.startsWith('http')) return;
        const realUrl = getRealUrl(a.href);
        if (isInternalLink(realUrl) || realUrl.includes('force-pass') || a.dataset.rickSafe === '1') return;

        e.preventDefault(); e.stopPropagation();
        GM_xmlhttpRequest({
            method: "POST",
            url: API_ENDPOINT,
            data: JSON.stringify({ url: realUrl }),
            headers: { "Content-Type": "application/json" },
            onload: (res) => {
                try {
                    const data = JSON.parse(res.responseText);
                    if (data.isRickroll) {
                        renderOverlay("链路风险拦截", realUrl, false);
                    } else {
                        a.dataset.rickSafe = '1';
                        if (a.target === '_blank' || e.ctrlKey || e.metaKey) window.open(realUrl, '_blank');
                        else window.location.href = realUrl;
                    }
                } catch (e) { window.location.href = realUrl; }
            }
        });
    }, true);

    checkIncoming();
    window.addEventListener('DOMContentLoaded', scanPage);
    setInterval(scanPage, 5000);
})();