<?php

declare(strict_types=1);

namespace Core;

use Redis;
use Throwable;

class RedisClient
{
    private static ?Redis $instance = null;
    private static bool $connectionFailed = false;

    private function __construct() {}
    private function __clone() {}

    public static function getInstance(): ?Redis
    {
        if (self::$connectionFailed) {
            return null;
        }

        if (self::$instance === null) {
            if (!class_exists('Redis')) {
                self::$connectionFailed = true;
                return null;
            }

            try {
                $config = require __DIR__ . '/../config/redis.php';
                $redis = new Redis();
                $connected = $redis->connect($config['host'], $config['port'], (float)$config['timeout']);

                if ($connected) {
                    if (!empty($config['password'])) {
                        $redis->auth($config['password']);
                    }
                    if (!empty($config['database'])) {
                        $redis->select((int)$config['database']);
                    }
                    $redis->setOption(Redis::OPT_PREFIX, $config['prefix']);
                    self::$instance = $redis;
                } else {
                    self::$connectionFailed = true;
                }
            } catch (Throwable $e) {
                self::$connectionFailed = true;
                error_log('[Redis Error] ' . $e->getMessage());
                return null;
            }
        }

        return self::$instance;
    }

    public static function get(string $key): ?string
    {
        $redis = self::getInstance();
        if (!$redis) return null;
        $val = $redis->get($key);
        return $val !== false ? (string)$val : null;
    }

    public static function set(string $key, string $value, int $ttlSeconds = 0): bool
    {
        $redis = self::getInstance();
        if (!$redis) return false;
        return $ttlSeconds > 0 ? (bool)$redis->setex($key, $ttlSeconds, $value) : (bool)$redis->set($key, $value);
    }

    public static function del(string $key): bool
    {
        $redis = self::getInstance();
        if (!$redis) return false;
        return (bool)$redis->del($key);
    }

    public static function has(string $key): bool
    {
        $redis = self::getInstance();
        if (!$redis) return false;
        return (bool)$redis->exists($key);
    }
}