<?php

/**
 * AVE.cms
 *
 * @package AVE.cms
 * @version 4.x
 * @filesource
 * @copyright © 2007-2025 AVE.cms, https://www.ave.gitget.ru
 *
 * @license GPL v.2
 */

class AVE_Session_DB
{
    public int $sess_lifetime;

    protected string $db_host;
    protected string $db_user;
    protected string $db_pass;
    protected string $db_dbase;
    protected string $db_prefix;

    private ?mysqli $mysql_connect = null;

    public function __construct()
    {
        require BASE_DIR . '/config/db.config.php';

        $this->db_host = $config['dbhost'];
        $this->db_user = $config['dbuser'];
        $this->db_pass = $config['dbpass'];
        $this->db_dbase = $config['dbname'];
        $this->db_prefix = $config['dbpref'];

        $this->sess_lifetime = (defined('SESSION_LIFETIME') && is_numeric(SESSION_LIFETIME))
            ? (int)SESSION_LIFETIME
            : (get_cfg_var("session.gc_maxlifetime") < 1440 ? 1440 : (int)get_cfg_var("session.gc_maxlifetime"));

        $this->connect();
    }

    private function connect(): void
    {
        $this->mysql_connect = new mysqli($this->db_host, $this->db_user, $this->db_pass, $this->db_dbase);

        if ($this->mysql_connect->connect_error) {
            $this->error();
        }

        $this->mysql_connect->set_charset('utf8');
    }

    private function ensureConnection(): bool
    {
        if (!($this->mysql_connect instanceof mysqli) || !$this->mysql_connect->ping()) {
            $this->connect();
            if (!$this->mysql_connect || $this->mysql_connect->connect_error) {
                return false;
            }
        }
        return true;
    }

    public function __destruct()
    {
        if ($this->mysql_connect instanceof mysqli) {
            $this->mysql_connect->close();
            $this->mysql_connect = null;
        }
    }

    public function _open(string $path, string $name): bool
    {
        return true;
    }

    public function _close(): bool
    {
        if (!$this->ensureConnection()) {
            return false;
        }

        $sql = "DELETE FROM " . $this->db_prefix . "_sessions WHERE expiry < ?";
        $stmt = $this->mysql_connect->prepare($sql);
        if (!$stmt) {
            error_log("Prepare failed in _close: " . $this->mysql_connect->error);
            return false;
        }
        $now = time();
        $stmt->bind_param('i', $now);
        $stmt->execute();
        $stmt->close();

        // Соединение не закрываем!

        return true;
    }

    public function _read(string $ses_id): string
    {
        if (!$this->ensureConnection()) {
            return '';
        }

        $sql = "SELECT value, Ip FROM " . $this->db_prefix . "_sessions WHERE sesskey = ? AND expiry > ?";
        $stmt = $this->mysql_connect->prepare($sql);
        if (!$stmt) {
            error_log("Prepare failed in _read: " . $this->mysql_connect->error);
            return '';
        }

        $now = time();
        $stmt->bind_param('si', $ses_id, $now);
        $stmt->execute();
        $stmt->bind_result($value, $ip);
        $result = '';
        if ($stmt->fetch() && $ip === ($_SERVER['REMOTE_ADDR'] ?? '')) {
            $result = $value;
        }
        $stmt->close();

        return $result;
    }

    public function _write(string $ses_id, string $data): bool
    {
        if (!$this->ensureConnection()) {
            return false;
        }

        $expiry = time() + $this->sess_lifetime;
        $remoteAddr = $_SERVER['REMOTE_ADDR'] ?? '';

        $sql = "INSERT INTO " . $this->db_prefix . "_sessions (sesskey, expiry, value, Ip, expire_datum)
                VALUES (?, ?, ?, ?, FROM_UNIXTIME(?,'%d.%m.%Y, %H:%i:%s'))
                ON DUPLICATE KEY UPDATE
                    expiry = VALUES(expiry),
                    value = VALUES(value),
                    Ip = VALUES(Ip),
                    expire_datum = VALUES(expire_datum)";

        $stmt = $this->mysql_connect->prepare($sql);
        if (!$stmt) {
            error_log("Prepare failed in _write: " . $this->mysql_connect->error);
            return false;
        }

        $stmt->bind_param('sisss', $ses_id, $expiry, $data, $remoteAddr, $expiry);
        $result = $stmt->execute();
        if (!$result) {
            error_log("Execute failed in _write: " . $stmt->error);
        }
        $stmt->close();

        return $result;
    }

    public function _destroy(string $ses_id): bool
    {
        if (!$this->ensureConnection()) {
            return false;
        }

        $sql = "DELETE FROM " . $this->db_prefix . "_sessions WHERE sesskey = ?";
        $stmt = $this->mysql_connect->prepare($sql);
        if (!$stmt) {
            error_log("Prepare failed in _destroy: " . $this->mysql_connect->error);
            return false;
        }

        $stmt->bind_param('s', $ses_id);
        $result = $stmt->execute();
        if (!$result) {
            error_log("Execute failed in _destroy: " . $stmt->error);
        }
        $stmt->close();

        return $result;
    }

    public function _gc(int $maxlifetime): bool
    {
        if (!$this->ensureConnection()) {
            return false;
        }

        $threshold = time() - $maxlifetime;
        $sql = "DELETE FROM " . $this->db_prefix . "_sessions WHERE expiry < ?";
        $stmt = $this->mysql_connect->prepare($sql);
        if (!$stmt) {
            error_log("Prepare failed in _gc: " . $this->mysql_connect->error);
            return false;
        }

        $stmt->bind_param('i', $threshold);
        $result = $stmt->execute();
        if (!$result) {
            error_log("Execute failed in _gc: " . $stmt->error);
        }
        $stmt->close();

        return $result;
    }

    private function error(): void
    {
        ob_start();
        header('HTTP/1.1 503 Service Temporarily Unavailable');
        header('Status: 503 Service Temporarily Unavailable');
        header('Retry-After: 3600');
        header('X-Powered-By:');
        echo "Error connect to MySQL.";
        die;
    }
}