js根据地区判断进行跳转页面

 <script>
    // 获取访问者的 IP 地址
function getVisitorIP() {
    return new Promise((resolve, reject) => {
        const xhr = new XMLHttpRequest();
        xhr.open('GET', 'https://ipinfo.io/json', true);
        xhr.onload = function () {
            if (xhr.status >= 200 && xhr.status < 300) {
                const responseData = JSON.parse(xhr.responseText);
                const ip = responseData.ip;
                resolve(ip);
            } else {
                reject(new Error('Failed to fetch IP address.'));
            }
        };
        xhr.onerror = function () {
            reject(new Error('Network error while fetching IP address.'));
        };
        xhr.send();
    });
}

// 根据 IP 地址获取城市信息
function getCityFromIP(ip) {
    return new Promise((resolve, reject) => {
        const xhr = new XMLHttpRequest();
        xhr.open('GET', `https://ipapi.co/${ip}/json/`, true);
        xhr.onload = function () {
            if (xhr.status >= 200 && xhr.status < 300) {
                const responseData = JSON.parse(xhr.responseText);
                const city = responseData.city;
                resolve(city);
            } else {
                reject(new Error('Failed to fetch city information.'));
            }
        };
        xhr.onerror = function () {
            reject(new Error('Network error while fetching city information.'));
        };
        xhr.send();
    });
}

// 判断是否是北上广深长沙
function isTargetCity(city) {
       const targetCities = ['北京', '上海', '广州', '深圳'];
    return targetCities.includes(city);
}

// 跳转逻辑
function redirectToBaidu() {
    window.location.href = 'https://4399.com/';
}


// 主逻辑：获取 IP 地址，然后根据 IP 地址获取城市信息，最后判断是否是目标城市
function checkCityAndRedirect() {
    getVisitorIP()
        .then((ip) => getCityFromIP(ip))
        .then((city) => {
            console.log('Visitor city:', city);

            if (isTargetCity(city)) {
                redirectToBaidu();
            } else {
                console.log('Not in target cities.');
            }
        })
        .catch((error) => {
            console.error('Error:', error.message);
        });
}

// 在页面加载完成后执行逻辑
window.onload = function () {
    checkCityAndRedirect();
};

</script>