<?php

/**
 * This file is part of the Nette Framework (https://nette.org)
 * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
 */
declare (strict_types=1);
namespace RectorPrefix202209\Nette\Utils;

use RectorPrefix202209\Nette;
/**
 * Paginating math.
 *
 * @property   int $page
 * @property-read int $firstPage
 * @property-read int|null $lastPage
 * @property-read int $firstItemOnPage
 * @property-read int $lastItemOnPage
 * @property   int $base
 * @property-read bool $first
 * @property-read bool $last
 * @property-read int|null $pageCount
 * @property   int $itemsPerPage
 * @property   int|null $itemCount
 * @property-read int $offset
 * @property-read int|null $countdownOffset
 * @property-read int $length
 */
class Paginator
{
    use Nette\SmartObject;
    /** @var int */
    private $base = 1;
    /** @var int */
    private $itemsPerPage = 1;
    /** @var int */
    private $page = 1;
    /** @var int|null */
    private $itemCount;
    /**
     * Sets current page number.
     * @return static
     */
    public function setPage(int $page)
    {
        $this->page = $page;
        return $this;
    }
    /**
     * Returns current page number.
     */
    public function getPage() : int
    {
        return $this->base + $this->getPageIndex();
    }
    /**
     * Returns first page number.
     */
    public function getFirstPage() : int
    {
        return $this->base;
    }
    /**
     * Returns last page number.
     */
    public function getLastPage() : ?int
    {
        return $this->itemCount === null ? null : $this->base + \max(0, $this->getPageCount() - 1);
    }
    /**
     * Returns the sequence number of the first element on the page
     */
    public function getFirstItemOnPage() : int
    {
        return $this->itemCount !== 0 ? $this->offset + 1 : 0;
    }
    /**
     * Returns the sequence number of the last element on the page
     */
    public function getLastItemOnPage() : int
    {
        return $this->offset + $this->length;
    }
    /**
     * Sets first page (base) number.
     * @return static
     */
    public function setBase(int $base)
    {
        $this->base = $base;
        return $this;
    }
    /**
     * Returns first page (base) number.
     */
    public function getBase() : int
    {
        return $this->base;
    }
    /**
     * Returns zero-based page number.
     */
    protected function getPageIndex() : int
    {
        $index = \max(0, $this->page - $this->base);
        return $this->itemCount === null ? $index : \min($index, \max(0, $this->getPageCount() - 1));
    }
    /**
     * Is the current page the first one?
     */
    public function isFirst() : bool
    {
        return $this->getPageIndex() === 0;
    }
    /**
     * Is the current page the last one?
     */
    public function isLast() : bool
    {
        return $this->itemCount === null ? \false : $this->getPageIndex() >= $this->getPageCount() - 1;
    }
    /**
     * Returns the total number of pages.
     */
    public function getPageCount() : ?int
    {
        return $this->itemCount === null ? null : (int) \ceil($this->itemCount / $this->itemsPerPage);
    }
    /**
     * Sets the number of items to display on a single page.
     * @return static
     */
    public function setItemsPerPage(int $itemsPerPage)
    {
        $this->itemsPerPage = \max(1, $itemsPerPage);
        return $this;
    }
    /**
     * Returns the number of items to display on a single page.
     */
    public function getItemsPerPage() : int
    {
        return $this->itemsPerPage;
    }
    /**
     * Sets the total number of items.
     * @return static
     */
    public function setItemCount(?int $itemCount = null)
    {
        $this->itemCount = $itemCount === null ? null : \max(0, $itemCount);
        return $this;
    }
    /**
     * Returns the total number of items.
     */
    public function getItemCount() : ?int
    {
        return $this->itemCount;
    }
    /**
     * Returns the absolute index of the first item on current page.
     */
    public function getOffset() : int
    {
        return $this->getPageIndex() * $this->itemsPerPage;
    }
    /**
     * Returns the absolute index of the first item on current page in countdown paging.
     */
    public function getCountdownOffset() : ?int
    {
        return $this->itemCount === null ? null : \max(0, $this->itemCount - ($this->getPageIndex() + 1) * $this->itemsPerPage);
    }
    /**
     * Returns the number of items on current page.
     */
    public function getLength() : int
    {
        return $this->itemCount === null ? $this->itemsPerPage : \min($this->itemsPerPage, $this->itemCount - $this->getPageIndex() * $this->itemsPerPage);
    }
}
