<?php

namespace App\Helpers;

class Paginator
{
    /**
     * 解析每页显示的条数
     *
     * @param  string  $perPageName
     * @param  int  $default
     * @param  int|null  $max
     * @return int
     */
    public static function resolvePerPage(string $perPageName = 'per_page', int $default = 20, ?int $max = null): int
    {
        $perPage = (int) request()->input($perPageName);

        if ($perPage >= 1) {
            if ($max !== null && $max >= 1 && $perPage >= $max) {
                return $max;
            }

            return $perPage;
        }

        return $default;
    }
}