<?php

class usersOnline
{
    private Redis $redis;

    static string $prefix = 'users_online';
    static int $userActiveTime = 10;

    public function __construct($pathToSock)
    {
        $this->redis = new Redis();
        $this->redis->connect($pathToSock);
        $this->redis->select(2);
    }

    /*
     * @param string $userKey
     *
     * @return void
     */
    public function add(string $userKey): void
    {
        if (!$this->isUserKeyExist($userKey)) {
            $this->redis->zAdd(self::$prefix, strtotime("+".self::$userActiveTime." minutes", time()), $userKey);
        } else {
            $this->redis->zAdd('users_online', ['XX'], strtotime("+".self::$userActiveTime." minutes", time()), $userKey);
        }
    }

    /*
     *
     * @return int
     */
    public function getOnline(): int
    {
        return $this->redis->zCount(self::$prefix, 0, strtotime("+".self::$userActiveTime." minutes", time()));
    }

    /*
     *
     * @return array
     */
    public function getOnlineUsers(): array
    {
        return $this->redis->zRangeByScore(self::$prefix, 0, strtotime("+".self::$userActiveTime." minutes", time()));
    }

    /*
     * @param string $userKey
     *
     * @return bool
     */
    public function isOnline(string $userKey): bool
    {
        $isOnline = $this->redis->zScore(self::$prefix, $userKey);
        if (!empty($isOnline) AND $isOnline > time()) {
            return true;
        } else {
            return false;
        }
    }

    /*
     *
     * @return void
     */
    public function clear(): void
    {
        $this->redis->zRemRangeByScore(self::$prefix, 0, time()-1);
    }

    /*
     * @param string $userKey
     *
     * @return bool
     */
    private function isUserKeyExist(string $userKey): bool
    {
        return $this->redis->zScore(self::$prefix, $userKey);
    }
}