function looksLikeAsset(pathname) {
    // 末段包含 .xxx 扩展名就当资源（.js/.css/.png/.map 等）
    return /\.[a-zA-Z0-9]{1,8}$/.test(pathname);
}

function isHtmlNavigation(request) {
    const method = request.method.toUpperCase();
    if (method !== "GET" && method !== "HEAD") return false;

    const accept = request.headers.get("accept") || "";
    // 浏览器访问页面通常会带 text/html
    if (!accept.includes("text/html")) return false;

    return true;
}

/**
 * 混淆 HTML，给标签增加随机冗余属性
 * @param {string} html 原始 HTML
 * @param {string} seed 用于随机的种子（如域名）
 * @returns {string} 混淆后的 HTML
 */
function obfuscateHtml(html, seed) {
    // 简单的伪随机函数
    let hash = 0;
    for (let i = 0; i < seed.length; i++) {
        hash = (hash << 5) - hash + seed.charCodeAt(i);
        hash |= 0;
    }
    const pseudoRandom = () => {
        hash = (hash * 16807) % 2147483647;
        return (hash - 1) / 2147483646;
    };

    const randomStr = (len) => {
        const chars = "abcdefghijklmnopqrstuvwxyz";
        let str = "";
        for (let i = 0; i < len; i++) {
            str += chars[Math.floor(pseudoRandom() * chars.length)];
        }
        return str;
    };

    // 1) 注入混淆属性到现有标签
    // 匹配常见的开始标签，如 <title, <script, <div, <span, <link, <meta, <p, <body
    // 排除已经闭合的标签和带 / 的结束标签
    const targetTags = ["title", "script", "div", "span", "link", "meta", "p", "body", "h1", "h2", "button", "img"];
    
    targetTags.forEach(tag => {
        const regex = new RegExp(`<${tag}(\\s|>)`, "gi");
        html = html.replace(regex, (match, p1) => {
            // 随机生成 1-2 个混淆属性
            const attrCount = 1 + Math.floor(pseudoRandom() * 2);
            let attrs = "";
            for (let i = 0; i < attrCount; i++) {
                attrs += ` ${randomStr(5 + Math.floor(pseudoRandom() * 5))}`;
            }
            return `<${tag}${attrs}${p1}`;
        });
    });

    // 2) 之前保留的冗余标签逻辑（可选，用户重点是属性，但也保留一些结构冗余）
    const tags = ["div", "span", "p", "i", "b"];
    const classes = ["hidden-content", "meta-info", "v-data", "loading-state", "wrapper-inner"];

    const generateJunk = (count) => {
        let junk = "\n<!-- obfuscation start -->\n";
        for (let i = 0; i < count; i++) {
            const tag = tags[Math.floor(pseudoRandom() * tags.length)];
            const cls = classes[Math.floor(pseudoRandom() * classes.length)];
            const id = "ui-" + Math.floor(pseudoRandom() * 10000);
            const extra = randomStr(6);
            junk += `<${tag} ${extra} id="${id}" class="${cls}" style="display:none; visibility:hidden; position:absolute; z-index:-1;"></${tag}>\n`;
        }
        junk += "<!-- obfuscation end -->\n";
        return junk;
    };

    if (html.includes("</body>")) {
        return html.replace("</body>", `${generateJunk(3 + Math.floor(pseudoRandom() * 5))}</body>`);
    }
    return html + generateJunk(3);
}


export default {
    async fetch(request, env, ctx) {
        const url = new URL(request.url);

        // 1) 国家/地区访问控制
        // 如果当前国家不是来自 AU, GB, UM, US, SG 这些的时候，显示为 /403.html
        const allowedCountries = ["AU", "GB", "UM", "US", "SG"];
        const country = request.cf ? request.cf.country : null;

        if (country && !allowedCountries.includes(country)) {
            // 构造 403.html 的请求路径
            const forbiddenUrl = new URL("/403.html", url.origin);
            const forbiddenResp = await fetch(forbiddenUrl.toString());
            const forbiddenHtml = await forbiddenResp.text();
            return new Response(forbiddenHtml, {
                status: 403,
                headers: { "Content-Type": "text/html;charset=UTF-8" }
            });
        }

        // 不是页面导航 or 看起来是静态资源：直接回源，不替换
        if (!isHtmlNavigation(request) || looksLikeAsset(url.pathname)) {
            return fetch(request);
        }

        const host = url.hostname;                 // e.g. bigwin7.vip
        const sub = host.split(".")[0] || "default";

        // 1) 子品牌配置表：根据 load.m.js 的 sites_config 配置
        const BRAND_MAP = {
            // 默认配置
            default: {
                BRAND_NAME: "UsSlot777",
                BRAND_TITLE: "UsSlot777 | Online Slots & Real Money Games",
                BRAND_DESCRIPTION:
                    "High-quality games, instant access, daily rewards, and a smooth experience built for serious slot fans.",
                BRAND_OG_TITLE: "UsSlot777 | Online Slots & Real Money Games",
                BRAND_OG_DESCRIPTION:
                    "High-quality games, instant access, daily rewards, and a smooth experience built for serious slot fans.",
                BRAND_HERO_TITLE: "Play America's Best Slots",
                BRAND_HERO_SUBTITLE:
                    "High-quality games, instant access, daily rewards, and a smooth experience built for serious slot fans.",
                BRAND_PRIMARY_CTA_TEXT: "Start Playing Now",
                BRAND_PRIMARY_CTA_LINK: "/start",
                SUPPORT_EMAIL: "support@usslot777.com",
                THEME_COLOR: "#0f172a",
                FAV_ICO: "./resources/favicons/favicon.ico",
                BRAND_LOGO: url.origin + "/resources/logos/logo.png",
                BRAND_OG_IMAGE: url.origin + "/resources/product/thumbn.webp",
            },

            // bigwin7.vip - 红色文字 + 金色7
            bigwin7: {
                BRAND_NAME: "BigWin7",
                BRAND_TITLE: "BigWin7 | Online Slots & Real Money Games",
                BRAND_DESCRIPTION:
                    "Experience the thrill of big wins with premium slot games.",
                BRAND_OG_TITLE: "BigWin7 | Online Slots & Real Money Games",
                BRAND_OG_DESCRIPTION:
                    "Experience the thrill of big wins with premium slot games.",
                BRAND_HERO_TITLE: "Experience Big Wins",
                BRAND_HERO_SUBTITLE:
                    "Experience the thrill of big wins with premium slot games.",
                BRAND_PRIMARY_CTA_TEXT: "Start Winning",
                BRAND_PRIMARY_CTA_LINK: "/start",
                SUPPORT_EMAIL: "support@bigwin7.vip",
                THEME_COLOR: "#B91C1C",
                FAV_ICO: "./resources/favicons/bigwin7.ico",
                BRAND_LOGO: url.origin + "/resources/logos/bigwin7.webp",
                BRAND_OG_IMAGE: url.origin + "/resources/product/thumbn.webp",
            },

            // bigwinrush.vip - 紫色/粉色文字 + 绿色$
            bigwinrush: {
                BRAND_NAME: "BigWinRush",
                BRAND_TITLE: "BigWinRush | Online Slots & Real Money Games",
                BRAND_DESCRIPTION:
                    "Rush to your biggest wins ever with exciting slot games.",
                BRAND_OG_TITLE: "BigWinRush | Online Slots & Real Money Games",
                BRAND_OG_DESCRIPTION:
                    "Rush to your biggest wins ever with exciting slot games.",
                BRAND_HERO_TITLE: "Rush to Big Wins",
                BRAND_HERO_SUBTITLE:
                    "Rush to your biggest wins ever with exciting slot games.",
                BRAND_PRIMARY_CTA_TEXT: "Join the Rush",
                BRAND_PRIMARY_CTA_LINK: "/start",
                SUPPORT_EMAIL: "support@bigwinrush.vip",
                THEME_COLOR: "#5B21B6",
                FAV_ICO: "./resources/favicons/bigwinrush.ico",
                BRAND_LOGO: url.origin + "/resources/logos/bigwinrush.webp",
                BRAND_OG_IMAGE: url.origin + "/resources/product/thumbn.webp",
            },

            // cashstorm.net - 青色/蓝绿龙卷风
            cashstorm: {
                BRAND_NAME: "CashStorm",
                BRAND_TITLE: "CashStorm | Online Slots & Real Money Games",
                BRAND_DESCRIPTION:
                    "Ride the storm and collect massive cash rewards.",
                BRAND_OG_TITLE: "CashStorm | Online Slots & Real Money Games",
                BRAND_OG_DESCRIPTION:
                    "Ride the storm and collect massive cash rewards.",
                BRAND_HERO_TITLE: "Ride the Cash Storm",
                BRAND_HERO_SUBTITLE:
                    "Ride the storm and collect massive cash rewards.",
                BRAND_PRIMARY_CTA_TEXT: "Enter the Storm",
                BRAND_PRIMARY_CTA_LINK: "/start",
                SUPPORT_EMAIL: "support@cashstorm.net",
                THEME_COLOR: "#0E7490",
                FAV_ICO: "./resources/favicons/cashstorm.ico",
                BRAND_LOGO: url.origin + "/resources/logos/cashstorm.webp",
                BRAND_OG_IMAGE: url.origin + "/resources/product/thumbn.webp",
            },

            // hotwinzone.net - 红色/橙色火焰
            hotwinzone: {
                BRAND_NAME: "HotWinZone",
                BRAND_TITLE: "HotWinZone | Online Slots & Real Money Games",
                BRAND_DESCRIPTION:
                    "Enter the hot zone where every spin is a winner.",
                BRAND_OG_TITLE: "HotWinZone | Online Slots & Real Money Games",
                BRAND_OG_DESCRIPTION:
                    "Enter the hot zone where every spin is a winner.",
                BRAND_HERO_TITLE: "Enter the Hot Zone",
                BRAND_HERO_SUBTITLE:
                    "Enter the hot zone where every spin is a winner.",
                BRAND_PRIMARY_CTA_TEXT: "Get Hot Wins",
                BRAND_PRIMARY_CTA_LINK: "/start",
                SUPPORT_EMAIL: "support@hotwinzone.net",
                THEME_COLOR: "#C2410C",
                FAV_ICO: "./resources/favicons/hotwinzone.ico",
                BRAND_LOGO: url.origin + "/resources/logos/hotwinzone.webp",
                BRAND_OG_IMAGE: url.origin + "/resources/product/thumbn.webp",
            },

            // jackpotfury.net - 红色/橙色火焰文字
            jackpotfury: {
                BRAND_NAME: "JackpotFury",
                BRAND_TITLE: "JackpotFury | Online Slots & Real Money Games",
                BRAND_DESCRIPTION:
                    "Unleash the fury and hit massive jackpots.",
                BRAND_OG_TITLE: "JackpotFury | Online Slots & Real Money Games",
                BRAND_OG_DESCRIPTION:
                    "Unleash the fury and hit massive jackpots.",
                BRAND_HERO_TITLE: "Unleash Jackpot Fury",
                BRAND_HERO_SUBTITLE:
                    "Unleash the fury and hit massive jackpots.",
                BRAND_PRIMARY_CTA_TEXT: "Hit Jackpots",
                BRAND_PRIMARY_CTA_LINK: "/start",
                SUPPORT_EMAIL: "support@jackpotfury.net",
                THEME_COLOR: "#B91C1C",
                FAV_ICO: "./resources/favicons/jackpotfury.ico",
                BRAND_LOGO: url.origin + "/resources/logos/jackpotfury.webp",
                BRAND_OG_IMAGE: url.origin + "/resources/product/thumbn.webp",
            },

            // luckyhitnow.vip - 绿色四叶草
            luckyhitnow: {
                BRAND_NAME: "LuckyHitNow",
                BRAND_TITLE: "LuckyHitNow | Online Slots & Real Money Games",
                BRAND_DESCRIPTION:
                    "Get lucky and hit big wins right now.",
                BRAND_OG_TITLE: "LuckyHitNow | Online Slots & Real Money Games",
                BRAND_OG_DESCRIPTION:
                    "Get lucky and hit big wins right now.",
                BRAND_HERO_TITLE: "Get Lucky Now",
                BRAND_HERO_SUBTITLE:
                    "Get lucky and hit big wins right now.",
                BRAND_PRIMARY_CTA_TEXT: "Try Your Luck",
                BRAND_PRIMARY_CTA_LINK: "/start",
                SUPPORT_EMAIL: "support@luckyhitnow.vip",
                THEME_COLOR: "#046E55",
                FAV_ICO: "./resources/favicons/luckyhitnow.ico",
                BRAND_LOGO: url.origin + "/resources/logos/luckyhitnow.webp",
                BRAND_OG_IMAGE: url.origin + "/resources/product/thumbn.webp",
            },

            // megacashgo.vip - 绿色/金色文字
            megacashgo: {
                BRAND_NAME: "MegaCashGo",
                BRAND_TITLE: "MegaCashGo | Online Slots & Real Money Games",
                BRAND_DESCRIPTION:
                    "Go big or go home with mega cash prizes.",
                BRAND_OG_TITLE: "MegaCashGo | Online Slots & Real Money Games",
                BRAND_OG_DESCRIPTION:
                    "Go big or go home with mega cash prizes.",
                BRAND_HERO_TITLE: "Go for Mega Cash",
                BRAND_HERO_SUBTITLE:
                    "Go big or go home with mega cash prizes.",
                BRAND_PRIMARY_CTA_TEXT: "Go Mega",
                BRAND_PRIMARY_CTA_LINK: "/start",
                SUPPORT_EMAIL: "support@megacashgo.vip",
                THEME_COLOR: "#046E55",
                FAV_ICO: "./resources/favicons/megacashgo.ico",
                BRAND_LOGO: url.origin + "/resources/logos/megacashgo.webp",
                BRAND_OG_IMAGE: url.origin + "/resources/product/thumbn.webp",
            },

            // rapidjackpot.vip - 橙色火箭
            rapidjackpot: {
                BRAND_NAME: "RapidJackpot",
                BRAND_TITLE: "RapidJackpot | Online Slots & Real Money Games",
                BRAND_DESCRIPTION:
                    "Fast spins, rapid jackpots, instant wins.",
                BRAND_OG_TITLE: "RapidJackpot | Online Slots & Real Money Games",
                BRAND_OG_DESCRIPTION:
                    "Fast spins, rapid jackpots, instant wins.",
                BRAND_HERO_TITLE: "Rapid Jackpots Await",
                BRAND_HERO_SUBTITLE:
                    "Fast spins, rapid jackpots, instant wins.",
                BRAND_PRIMARY_CTA_TEXT: "Win Fast",
                BRAND_PRIMARY_CTA_LINK: "/start",
                SUPPORT_EMAIL: "support@rapidjackpot.vip",
                THEME_COLOR: "#C2410C",
                FAV_ICO: "./resources/favicons/rapidjackpot.ico",
                BRAND_LOGO: url.origin + "/resources/logos/rapidjackpot.webp",
                BRAND_OG_IMAGE: url.origin + "/resources/product/thumbn.webp",
            },

            // slotfrenzy.vip - 红色/黄色小丑
            slotfrenzy: {
                BRAND_NAME: "SlotFrenzy",
                BRAND_TITLE: "SlotFrenzy | Online Slots & Real Money Games",
                BRAND_DESCRIPTION:
                    "Join the frenzy with non-stop slot action.",
                BRAND_OG_TITLE: "SlotFrenzy | Online Slots & Real Money Games",
                BRAND_OG_DESCRIPTION:
                    "Join the frenzy with non-stop slot action.",
                BRAND_HERO_TITLE: "Join the Slot Frenzy",
                BRAND_HERO_SUBTITLE:
                    "Join the frenzy with non-stop slot action.",
                BRAND_PRIMARY_CTA_TEXT: "Go Frenzy",
                BRAND_PRIMARY_CTA_LINK: "/start",
                SUPPORT_EMAIL: "support@slotfrenzy.vip",
                THEME_COLOR: "#B91C1C",
                FAV_ICO: "./resources/favicons/slotfrenzy.ico",
                BRAND_LOGO: url.origin + "/resources/logos/slotfrenzy.webp",
                BRAND_OG_IMAGE: url.origin + "/resources/product/thumbn.webp",
            },

            // spinblitz.vip - 蓝色文字 + 黄色闪电
            spinblitz: {
                BRAND_NAME: "SpinBlitz",
                BRAND_TITLE: "SpinBlitz | Online Slots & Real Money Games",
                BRAND_DESCRIPTION:
                    "Blitz through wins with lightning-fast spins.",
                BRAND_OG_TITLE: "SpinBlitz | Online Slots & Real Money Games",
                BRAND_OG_DESCRIPTION:
                    "Blitz through wins with lightning-fast spins.",
                BRAND_HERO_TITLE: "Blitz to Victory",
                BRAND_HERO_SUBTITLE:
                    "Blitz through wins with lightning-fast spins.",
                BRAND_PRIMARY_CTA_TEXT: "Start Blitz",
                BRAND_PRIMARY_CTA_LINK: "/start",
                SUPPORT_EMAIL: "support@spinblitz.vip",
                THEME_COLOR: "#1E40AF",
                FAV_ICO: "./resources/favicons/spinblitz.ico",
                BRAND_LOGO: url.origin + "/resources/logos/spinblitz.webp",
                BRAND_OG_IMAGE: url.origin + "/resources/product/thumbn.webp",
            },

            // ultrawinner.net - 蓝色/紫色钻石
            ultrawinner: {
                BRAND_NAME: "UltraWinner",
                BRAND_TITLE: "UltraWinner | Online Slots & Real Money Games",
                BRAND_DESCRIPTION:
                    "Become the ultimate winner with ultra rewards.",
                BRAND_OG_TITLE: "UltraWinner | Online Slots & Real Money Games",
                BRAND_OG_DESCRIPTION:
                    "Become the ultimate winner with ultra rewards.",
                BRAND_HERO_TITLE: "Be the Ultra Winner",
                BRAND_HERO_SUBTITLE:
                    "Become the ultimate winner with ultra rewards.",
                BRAND_PRIMARY_CTA_TEXT: "Win Ultra",
                BRAND_PRIMARY_CTA_LINK: "/start",
                SUPPORT_EMAIL: "support@ultrawinner.net",
                THEME_COLOR: "#5B21B6",
                FAV_ICO: "./resources/favicons/ultrawinner.ico",
                BRAND_LOGO: url.origin + "/resources/logos/ultrawinner.webp",
                BRAND_OG_IMAGE: url.origin + "/resources/product/thumbn.webp",
            },

            // winexplosion.vip - 红色/黄色/绿色混合
            winexplosion: {
                BRAND_NAME: "WinExplosion",
                BRAND_TITLE: "WinExplosion | Online Slots & Real Money Games",
                BRAND_DESCRIPTION:
                    "Explosive wins await in every spin.",
                BRAND_OG_TITLE: "WinExplosion | Online Slots & Real Money Games",
                BRAND_OG_DESCRIPTION:
                    "Explosive wins await in every spin.",
                BRAND_HERO_TITLE: "Explosive Wins Await",
                BRAND_HERO_SUBTITLE:
                    "Explosive wins await in every spin.",
                BRAND_PRIMARY_CTA_TEXT: "Explode to Win",
                BRAND_PRIMARY_CTA_LINK: "/start",
                SUPPORT_EMAIL: "support@winexplosion.vip",
                THEME_COLOR: "#B91C1C",
                FAV_ICO: "./resources/favicons/winexplosion.ico",
                BRAND_LOGO: url.origin + "/resources/logos/winexplosion.webp",
                BRAND_OG_IMAGE: url.origin + "/resources/product/thumbn.webp",
            },
        };

        const brand = BRAND_MAP[sub] || BRAND_MAP.default;

        // 2) 计算 BRAND_URL（保持当前 host，不要写死）
        brand.BRAND_URL = `${url.protocol}//${host}${url.pathname === "/" ? "/" : url.pathname}`;

        // 3) 拉取源站 HTML（如果你是 Pages，可直接 return new Response(...) 处理）
        // 这里用"回源"方式示例：把请求转发到真正的源站（例如你的 Pages/服务器）
        const originResp = await fetch(request);

        // 非 HTML 资源直接透传（css/js/png 等）
        const contentType = originResp.headers.get("content-type") || "";
        if (!contentType.includes("text/html")) return originResp;

        // 4) 用 HTMLRewriter + 文本替换
        // HTMLRewriter 更适合替换 title/meta；占位符替换更适合批量文本替换
        // 这里两种一起用：先把响应体转文本做占位符替换，再返回
        let html = await originResp.text();

        // 4.1 占位符替换（%%KEY%%）
        for (const [k, v] of Object.entries(brand)) {
            const safeV = String(v).replaceAll("$", "&#36;"); // 防止某些模板字符串/特殊符号干扰
            html = html.replaceAll(`%%${k}%%`, safeV);
        }

        // 4.2 如果路径包含 landingpage 或 startup，则进行混淆
        if (url.pathname.includes("landingpage") || url.pathname.includes("startup")) {
            html = obfuscateHtml(html, host);
        }

        // 4.3 安全兜底：如果页面里存在未替换占位符，可选择清空或保留
        // html = html.replace(/%%[A-Z0-9_]+%%/g, "");

        // 5) 返回响应（保留原响应的大部分 header，但要修正 content-length）
        const newHeaders = new Headers(originResp.headers);
        newHeaders.delete("content-length");

        return new Response(html, {
            status: originResp.status,
            statusText: originResp.statusText,
            headers: newHeaders,
        });
    },
};