<?php

/**
 * 分页驱动
 * @author  Devil
 * @version v_1.0.0
 */
class PageLibrary
{
    private $page;
    private $total;
    private $number;
    private $bt_number;
    private $where;
    private $page_total;
    private $url;
    private $html;

    /**
     * [__construct description]
     * @param [int]    $param['total']      [数据总数]
     * @param [int]    $param['number']     [每页数据条数]
     * @param [int]    $param['bt_number']  [分页显示按钮个数]
     * @param [array]  $param['where']      [额外条件(键值对)]
     * @param [string] $param['url']        [url地址]
     */
    public function __construct($param = array())
    {
        $this->page = max(1, isset($_REQUEST['page']) ? intval($_REQUEST['page']) : 1);
        $this->total = max(1, isset($param['total']) ? intval($param['total']) : 1);
        $this->number = max(1, isset($param['number']) ? intval($param['number']) : 1);
        $this->bt_number = isset($param['bt_number']) ? intval($param['bt_number']) : 2;
        $this->where = (isset($param['where']) && is_array($param['where'])) ? $param['where'] : '';
        $this->url = isset($param['url']) ? $param['url'] : '';
        $this->page_total = 1;
        $this->html = '';

        /* 参数设置 */
        $this->SetParem();
    }

    /**
     * [SetParem 参数设置]
     */
    private function SetParem()
    {
        /* 防止超出最大页码数 */
        $this->page_total = ceil($this->total/$this->number);
        if($this->page > $this->page_total) $this->page = $this->page_total;

        /* 额外条件url设置 */
        if(!empty($this->where) && is_array($this->where))
        {
            foreach($this->where as $k=>$v) $this->url .= '&'.$k.'='.$v;
        }

    }

    /**
     * [GetPageHtml 获取生成好的分页代码]
     */
    public function GetPageHtml()
    {
        $this->html .= '<ul class="am-pagination am-pagination-centered"><li';
        $this->html .= ($this->page > 1) ? '' : ' class="am-disabled"';
        $this->html .= '><a href="'.$this->url.'&page='.($this->page-1).'" class="meila-radius">&laquo;</a></li>';
        $this->html .= $this->GetButtonNumberHtml();
        $this->html .= '<li';
        $this->html .= ($this->page > 0 && $this->page < $this->page_total) ? '' : ' class="am-disabled"';
        $this->html .= '><a href="'.$this->url.'&page='.($this->page+1).'" class="meila-radius">&raquo;</a></li></ul>';

        return $this->html;
    }

    /**
     * [GetButtonNumberHtml 获取button显示个数的html]
     * @return [string] [按钮个数html代码]
     */
    private function GetButtonNumberHtml()
    {
        $html_before = '';
        $html_after = '';
        $html_page = '<li class="am-active"><a class="meila-radius">'.$this->page.'</a></li>';
        if($this->bt_number > 0)
        {
            /* 前按钮 */
            if($this->page > 1)
            {
                $total = ($this->page-$this->bt_number < 1) ? 1 : $this->page-$this->bt_number;
                for($i=$this->page-1; $i>=$total; $i--)
                {
                    $html_before = '<li><a href="'.$this->url.'&page='.$i.'" class="meila-radius">'.$i.'</a></li>'.$html_before;
                }
            }

            /* 后按钮 */
            if($this->page_total > $this->page)
            {
                $total = ($this->page+$this->bt_number > $this->page_total) ? $this->page_total : $this->page+$this->bt_number;
                for($i=$this->page+1; $i<=$total; $i++)
                {
                    $html_after .= '<li><a href="'.$this->url.'&page='.$i.'" class="meila-radius">'.$i.'</a></li>';
                }
            }
        }
        return $html_before.$html_page.$html_after;
    }

    /**
     * [GetPageStarNumber 获取分页起始值]
     */
    public function GetPageStarNumber()
    {
        return intval(($this->page-1)*$this->number);
    }
}
?>