<?php
header('Content-Type: application/json; charset=utf-8');
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, POST, OPTIONS');
header('Access-Control-Allow-Headers: Content-Type');

if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    http_response_code(200);
    exit;
}

function getServerLoad() {
    $load = sys_getloadavg();
    return [
        '1min' => round($load[0], 2),
        '5min' => round($load[1], 2),
        '15min' => round($load[2], 2)
    ];
}

function getNetworkLatency() {
    $hosts = [
        '8.8.8.8' => 'Google DNS',
        '1.1.1.1' => 'Cloudflare DNS',
        '114.114.114.114' => '114 DNS'
    ];

    $results = [];
    foreach ($hosts as $ip => $name) {
        $start = microtime(true);
        $socket = @fsockopen($ip, 53, $errno, $errstr, 2);
        $end = microtime(true);

        if ($socket) {
            fclose($socket);
            $latency = round(($end - $start) * 1000, 2);
            $results[] = [
                'host' => $name,
                'ip' => $ip,
                'latency' => $latency,
                'status' => 'online'
            ];
        } else {
            $results[] = [
                'host' => $name,
                'ip' => $ip,
                'latency' => null,
                'status' => 'offline'
            ];
        }
    }

    return $results;
}

function getTimestamp() {
    return [
        'unix' => time(),
        'datetime' => date('Y-m-d H:i:s'),
        'timezone' => date_default_timezone_get()
    ];
}

// 记录请求开始时间
$start_time = microtime(true);

$response = [
    'status' => 'success',
    'timestamp' => getTimestamp(),
    'server' => [
        'load' => getServerLoad()
    ],
    'network' => [
        'latency' => getNetworkLatency(),
        'server_response_time' => round((microtime(true) - $start_time) * 1000, 2) // 服务器响应时间（毫秒）
    ]
];

echo json_encode($response, JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT);
?>