<?php
use Craft;
use craftelementsEntry;
use crafthelpersUrlHelper;

function requireLogin(){
    header("Access-Control-Allow-Origin: *");
    header("Access-Control-Allow-Headers: X-Requested-With");

    if (!Craft::$app->user->isGuest) {
        // you are authenticated
    } else {
        // check params
        $loginName = Craft::$app->request->getQueryParam('loginName');
        $password = Craft::$app->request->getQueryParam('password');

        if (Craft::$app->user->login($loginName, $password)) {
            // login success
            $user = Craft::$app->userSession->getUser();
        } else {
            // login fails echo message
            $errorCode = Craft::$app->userSession->getLoginErrorCode();
            $errorMessage = Craft::$app->userSession->getLoginErrorMessage($errorCode, $loginName);
            Craft::$app->end(JsonHelper::encode(array('data' => array( ['status' => 'error','message' =>'wrong login']  ))));
        }
    }

}

return [
...