<?php
class Page
{
    private $each_disNums; //每页显示的条目数
    private $nums; //总条目数
    private $current_page; //当前被选中的页
    private $sub_pages; //每次显示的页数
    private $pageNums; //总页数
    private $page_array = array(); //用来构造分页的数组
    private $subPage_link; //每个分页的链接
    /**
     *
     * __construct是SubPages的构造函数，用来在创建类的时候自动运行.
     * @$each_disNums   每页显示的条目数
     * @nums     总条目数
     * @current_num     当前被选中的页
     * @sub_pages       每次显示的页数
     * @subPage_link    每个分页的链接
     * @subPage_type    显示分页的类型
     *
     * 当@subPage_type=1的时候为普通分页模式
     *    example：   共4523条记录,每页显示10条,当前第1/453页 [首页] [上页] [下页] [尾页]
     *    当@subPage_type=2的时候为经典分页样式
     *     example：   当前第1/453页 [首页] [上页] 1 2 3 4 5 6 7 8 9 10 [下页] [尾页]
     */
    public function __construct($each_disNums, $nums, $current_page, $sub_pages)
    {
        $this->each_disNums = intval($each_disNums);
        $this->nums         = intval($nums);
        if (!$current_page) {
            $this->current_page = 1;
        } else {
            $this->current_page = intval($current_page);
        }
        $this->sub_pages    = intval($sub_pages);
        $this->pageNums     = ceil($nums / $each_disNums);
        $uri                = $_SERVER['REQUEST_URI'];
        $uri                = str_replace('&page=' . $this->current_page, '', $uri);
        $uri                = str_replace('?page=' . $this->current_page, '', $uri);
        $this->subPage_link = Typecho_Widget::widget('Widget_Options')->index . $uri . "&page=";
    }

    /*
    __destruct析构函数，当类不在使用的时候调用，该函数用来释放资源。
     */
    public function __destruct()
    {
        unset($each_disNums);
        unset($nums);
        unset($current_page);
        unset($sub_pages);
        unset($pageNums);
        unset($page_array);
        unset($subPage_link);
    }
    /*
    用来给建立分页的数组初始化的函数。
     */
    public function initArray()
    {
        for ($i = 0; $i < $this->sub_pages; $i++) {
            $this->page_array[$i] = $i;
        }
        return $this->page_array;
    }
    /*
    construct_num_Page该函数使用来构造显示的条目
    即使：[1][2][3][4][5][6][7][8][9][10]
     */
    public function construct_num_Page()
    {
        if ($this->pageNums < $this->sub_pages) {
            $current_array = array();
            for ($i = 0; $i < $this->pageNums; $i++) {
                $current_array[$i] = $i + 1;
            }
        } else {
            $current_array = $this->initArray();
            if ($this->current_page <= 3) {
                for ($i = 0; $i < count($current_array); $i++) {
                    $current_array[$i] = $i + 1;
                }
            } elseif ($this->current_page <= $this->pageNums && $this->current_page > $this->pageNums - $this->sub_pages + 1) {
                for ($i = 0; $i < count($current_array); $i++) {
                    $current_array[$i] = ($this->pageNums) - ($this->sub_pages) + 1 + $i;
                }
            } else {
                for ($i = 0; $i < count($current_array); $i++) {
                    $current_array[$i] = $this->current_page - 2 + $i;
                }
            }
        }
        return $current_array;
    }
    /*
    构造经典模式的分页
    当前第1/453页 [首页] [上页] 1 2 3 4 5 6 7 8 9 10 [下页] [尾页]
     */
    public function show()
    {
        $str = "";
        if ($this->current_page > 1) {
            $firstPageUrl = $this->subPage_link . "1";
            $prevPageUrl  = $this->subPage_link . ($this->current_page - 1);
            $str .= '<li class="page-item"><a class="page-link" href="' . $prevPageUrl . '">&laquo;</a></li>';
        } else {
            $str .= '';
        }
        $a = $this->construct_num_Page();
        for ($i = 0; $i < count($a); $i++) {
            $s = $a[$i];
            if ($s == $this->current_page) {
                $str .= '<li class="page-item active" aria-current="page"><a class="page-link" href="' . $url . '">' . $s . '<span class="visually-hidden">(current)</span></a></li>';
            } else {
                $url = $this->subPage_link . $s;
                $str .= '<li class="page-item"><a class="page-link" href="' . $url . '">' . $s . '</a></li>';
            }
        }
        if ($this->current_page < $this->pageNums) {
            $lastPageUrl = $this->subPage_link . $this->pageNums;
            $nextPageUrl = $this->subPage_link . ($this->current_page + 1);
            $str .= '<li class="page-item"><a class="page-link" href="' . $nextPageUrl . '">&raquo;</a></li>';
        } else {
            $str .= '';
        }
        return $str;
    }

}
