<?php
namespace tool;

use think\Paginator;

/**
 * 自定义分页模板
 * Class CustomPageHelper
 * @package tool
 */
class CustomPageHelper extends Paginator
{
    // 中间页码按钮个数
    protected $btnNumber = 10;

    // 首页
    protected function getFirstButton($str = '')
    {
        if ($this->currentPage() <= 1) {
            return $this->getDisabledTextWrapper($str);
        }

        $url = $this->url(1);

        return $this->getPageLinkWrapper($url, $str);
    }

    // 上一页
    protected function getPreviousButton($text = "&laquo;")
    {

        if ($this->currentPage() <= 1) {
            return $this->getDisabledTextWrapper($text, 'prev');
        }

        $url = $this->url(
            $this->currentPage() - 1
        );

        return $this->getPageLinkWrapper($url, $text, 'prev');
    }

    // 页码
    protected function getLinks()
    {
        if ($this->total > $this->listRows) {
            if ($this->lastPage < $this->btnNumber) {
                return $this->getUrlLinks($this->getUrlRange(1, $this->lastPage), false);
            } else {
                $min = 1;
                if ($this->currentPage > $this->btnNumber / 2) $min = $this->currentPage - floor($this->btnNumber / 2);
                if ($this->lastPage - $this->currentPage < $this->btnNumber / 2) $min = $this->lastPage - $this->btnNumber + 1;
                $max = $min + $this->btnNumber - 1;
                $ellipsis = false;
                if ($this->lastPage > $max)  {
                    $ellipsis = true;
                    $max = $max - 1;
                }
                return $this->getUrlLinks($this->getUrlRange($min, $max), $ellipsis);
            }
        }
    }

    // 下一页
    protected function getNextButton($text = '&raquo;')
    {
        if (!$this->hasMore) {
            return $this->getDisabledTextWrapper($text, 'next');
        }

        $url = $this->url($this->currentPage() + 1);

        return $this->getPageLinkWrapper($url, $text, 'next');
    }

    // 末页
    protected function getLastButton($text = '')
    {
        if (!$this->hasMore) {
            return $this->getDisabledTextWrapper($text);
        }

        $url = $this->url($this->lastPage());

        return $this->getPageLinkWrapper($url, $text);
    }

    // 渲染分页 $btnNumber [0 只显示上下页 | >= 3]
    public function render($btnNumber = 10, $type = '')
    {
        if($btnNumber == 0 || $btnNumber >= 3) {
            $this->btnNumber = $btnNumber;
        }
        //数据是否足够分页
        if ($this->hasPages()) {
            if(strtoupper($type) == 'A') {
                return sprintf(
                    '<ul class="pageing">%s %s %s %s</ul>',
                    $this->getFirstButton('首页'),
                    $this->getPreviousButton('上一页'),
                    $this->getLinks(),
                    $this->getNextButton('下一页')
                );
            } elseif (strtoupper($type) == 'B') {
                return sprintf(
                    '<ul class="pageing">%s %s %s %s %s</ul>',
                    $this->getFirstButton('首页'),
                    $this->getPreviousButton('上一页'),
                    $this->getLinks(),
                    $this->getNextButton('下一页'),
                    $this->getLastButton('末页')
                );
            } else {
                return sprintf(
                    '<ul class="pageing">%s %s %s</ul>',
                    $this->getPreviousButton('上一页'),
                    $this->getLinks(),
                    $this->getNextButton('下一页')
                );
            }
        }
    }

    // 生成禁用按钮
    protected function getDisabledTextWrapper($text, $htmlClass = '')
    {
        return '<li class="disabled '.$htmlClass.'"><span>' . $text . '</span></li>';
    }

    // 生成普通按钮
    protected function getPageLinkWrapper($url, $page, $htmlClass = '')
    {
        if ($page == $this->currentPage()) {
            return $this->getActivePageWrapper($page, $htmlClass);
        }

        return $this->getAvailablePageWrapper($url, $page, $htmlClass);
    }

    // 生成当前页按钮
    protected function getActivePageWrapper($text, $htmlClass = '')
    {
        return '<li class="cur "'.$htmlClass.'><span>' . $text . '</span></li>';
    }

    // 可点击按钮
    protected function getAvailablePageWrapper($url, $page, $htmlClass = '')
    {
        return '<li class="'.$htmlClass.'"><a href="' . htmlentities($url) . '">' . $page . '</a></li>';
    }

    // 批量生成页码按钮
    protected function getUrlLinks(array $urls, bool $ellipsis, $htmlClass = '')
    {
        $html = '';

        foreach ($urls as $page => $url) {
            $html .= $this->getPageLinkWrapper($url, $page, $htmlClass);
        }
        if($ellipsis && $this->btnNumber > 0) {
            $html .= $this->getDisabledTextWrapper('...', $htmlClass);
        }

        return $html;
    }

}