<?php
// no direct access
defined('ABSPATH') or die();

if(!class_exists('LSD_id')):

/**
 * Listdom ID class.
 */
class LSD_id
{
    /**
     * The single instance of the class.
     *
     * @var LSD_id
     * @since 1.0.0
     */
    protected static $instance = null;

    /**
     * All IDs that are loaded
     * @var array
     */
    protected static $IDs = [];

    /**
     * Main LSD_id Instance.
     * Ensures only one instance of LSD_id is loaded or can be loaded.
     * @since 1.0.0
     * @static
     * @return LSD_id
     */
    public static function instance()
    {
        // Get an instance of Class
        if(is_null(self::$instance)) self::$instance = new self();

        // Return the instance
        return self::$instance;
    }

    /**
     * Cloning is forbidden.
     * @since 1.0.0
     */
    public function __clone()
    {
        _doing_it_wrong(__FUNCTION__, esc_html__('Cheating huh?', 'listdom'), '1.0.0');
    }

    /**
     * Unserializing instances of this class is forbidden.
     * @since 1.0.0
     */
    public function __wakeup()
    {
        _doing_it_wrong(__FUNCTION__, esc_html__('Cheating huh?', 'listdom'), '1.0.0');
    }

    /**
     * Listdom Constructor.
     */
    protected function __construct()
    {
    }

    public static function get($id)
    {
        $instance = self::instance();
        if($instance->duplicated($id))
        {
            $id = $instance->unique();

            $instance->add($id);
            return $id;
        }
        else
        {
            $instance->add($id);
            return $id;
        }
    }

    public function duplicated($id)
    {
        return in_array($id, self::$IDs);
    }

    public function add($id)
    {
        self::$IDs[] = $id;
    }

    public function unique()
    {
        $id = mt_rand(1000, 9999);
        if($this->duplicated($id)) $id = $this->unique();

        return $id;
    }

    public static function code($length = 10)
    {
        $keys = array_merge(range(0, 9), range('A', 'Z'), range('a', 'z'));

        $key = '';
        for($i = 0; $i < $length; $i++) $key .= $keys[array_rand($keys)];

        return $key;
    }
}

endif;