<?php
namespace VendorModuleControllerIndex;

use MagentoFrameworkAppActionContext;
use MagentoFrameworkViewResultPageFactory;

class Devicedetect extends MagentoFrameworkAppActionAction
{
    /**
     * @var PageFactory
     */
    protected $_pageFactory;

    /**
     * initialization
     *
     * @param Context $context
     * @param PageFactory $pageFactory
     */
    public function __construct(
        Context $context,
        PageFactory $pageFactory
    ) {
        $this->_pageFactory = $pageFactory;
        parent::__construct($context);
    }
    
    /**
     * Execute method
     */
    public function execute()
    {
        $resultPage = $this->_pageFactory->create();
        $userAgent  = $this->getRequest()->getHeader('useragent');
        $server     = $this->getRequest()->getServer();
         
        //Check device is Desktop
        $isDesktopDevice = Zend_Http_UserAgent_Desktop::match($userAgent, $server);
        if ($isDesktopDevice) {
            $resultPage->getConfig()->getTitle()->set(__("Desktop Detect"));
        }
        //Check device is Mobile
        $isMobileDevice = Zend_Http_UserAgent_Mobile::match($userAgent, $server);
        if ($isMobileDevice) {
            $resultPage->getConfig()->getTitle()->set(__("Mobile Detect"));
        }  
        return $resultPage;
    }
}