<?php

function getUsersList() {

    $array = include __DIR__ . '/array.php';
    return $array;
}

function existsUser($login) {

    $users = getUsersList();
    $userlogin = in_array($login, array_column($users, 'login'));
    if ($userlogin) {
        return true;
    }
}

function сheckPassword($login, $password) {

    $users = getUsersList();
    if (existsUser($login)){
        foreach ($users as $user){
            if($user['login'] == $login){
                $hash = $user['password'];
            }
         }
        if(password_verify($password, $hash)){
            return true;
        }
    }
}

function getCurrentUser() {
    $users = getUsersList();
    if(!isset($_SESSION['login'])){
        return null;
    }
    $login = $_SESSION['login'];
    foreach ($users as $user){
        if($user['login'] == $login){
            $username = $user['username'];
        }
    }
    return $username;
}