<?php
//命名空間的名稱與上級目錄tools一致
//原因：當前Page.class.php類文件會被自動加載機制引入
//   在引入的同時會把"tools"變為文件的上級目錄，進而獲得該Page類文件
namespace Tools;

class Page {
  private $total; //數據表中總記錄數
  private $listRows; //每頁顯示行數
  private $limit;
  private $uri;  //當前鏈接URL
  private $pageNum; //頁數
  private $config=array('header'=>"個記錄", "prev"=>"上一頁", "next"=>"下一頁", "first"=>"首 頁", "last"=>"尾 頁");
  private $listNum=8; //限制頁碼列表數目
  
  /*
   * $total 總記錄數
   * $listRows 每頁顯示行數
   */
  public function __construct($total, $listRows=10, $pa=""){
    $this->total=$total;  //數據表中總記錄數
    $this->listRows=$listRows; //設置每頁顯示行數
    $this->uri=$this->getUri($pa); //請求地址
    $this->page=!empty($_GET["page"]) ? $_GET["page"] : 1; //當前頁
    $this->pageNum=ceil($this->total/$this->listRows); //總頁數
    $this->limit=$this->setLimit(); //限制每頁長度
  }

  private function setLimit(){
    return "Limit ".($this->page-1)*$this->listRows.", {$this->listRows}";
  }

  //請求地址
  private function getUri($pa){
    $url=$_SERVER["REQUEST_URI"].(strpos($_SERVER["REQUEST_URI"], '?')?'':"?").$pa;
    $parse=parse_url($url);

  

    if(isset($parse["query"])){
      parse_str($parse['query'],$params);
      unset($params["page"]);
      $url=$parse['path'].'?'.http_build_query($params);
      
    }

    return $url;
  }

  function __get($args){
    if($args=="limit")
      return $this->limit;
    else
      return null;
  }

  //開始頁，從哪一條顯示
  private function start(){
    if($this->total==0)
      return 0;
    else
      return ($this->page-1)*$this->listRows+1;
  }

  //從哪一條結束
  private function end(){
    return min($this->page*$this->listRows,$this->total);
  }

  //首頁超鏈接
  private function first(){
    $html = "";
    if($this->page==1)
      $html.='';
    else
      $html.="  <a href='{$this->uri}&page=1'>{$this->config["first"]}</a>  ";

    return $html;
  }

  //上一頁
  private function prev(){
    $html = "";
    if($this->page==1)
      $html.='';
    else
      $html.="  <a href='{$this->uri}&page=".($this->page-1)."'>{$this->config["prev"]}</a>  ";

    return $html;
  }

  //頁碼數字列表超鏈接
  private function pageList(){
    $linkPage="";
    
    $inum=floor($this->listNum/2);
  
    for($i=$inum; $i>=1; $i--){
      $page=$this->page-$i;

      if($page<1)
        continue;

      $linkPage.=" <a href='{$this->uri}&page={$page}'>{$page}</a> ";

    }
  
    $linkPage.=" {$this->page} ";
    

    for($i=1; $i<=$inum; $i++){
      $page=$this->page+$i;
      if($page<=$this->pageNum)
        $linkPage.=" <a href='{$this->uri}&page={$page}'>{$page}</a> ";
      else
        break;
    }

    return $linkPage;
  }

  //下一頁
  private function next(){
    $html = "";
    if($this->page==$this->pageNum)
      $html.='';
    else
      $html.="  <a href='{$this->uri}&page=".($this->page+1)."'>{$this->config["next"]}</a>  ";

    return $html;
  }

  //尾頁
  private function last(){
    $html = "";
    if($this->page==$this->pageNum)
      $html.='';
    else
      $html.="  <a href='{$this->uri}&page=".($this->pageNum)."'>{$this->config["last"]}</a>  ";

    return $html;
  }

  //跳轉
  private function goPage(){
    return '  <input type="text" onkeydown="javascript:if(event.keyCode==13){var page=(this.value>'.$this->pageNum.')?'.$this->pageNum.':this.value;location=\''.$this->uri.'&page=\'+page+\'\'}" value="'.$this->page.'" style="width:25px"><input type="button" value="GO" onclick="javascript:var page=(this.previousSibling.value>'.$this->pageNum.')?'.$this->pageNum.':this.previousSibling.value;location=\''.$this->uri.'&page=\'+page+\'\'">  ';
  }

  //頁碼列表
  function fpage($display=array(0,1,2,3,4,5,6,7,8)){
    $html[0]="  共有<b>{$this->total}</b>{$this->config["header"]}  ";
    $html[1]="  每頁顯示<b>".($this->end()-$this->start()+1)."</b>條，本頁<b>{$this->start()}-{$this->end()}</b>條  ";
    $html[2]="  <b>{$this->page}/{$this->pageNum}</b>頁  ";
    
    $html[3]=$this->first();
    $html[4]=$this->prev();
    $html[5]=$this->pageList();
    $html[6]=$this->next();
    $html[7]=$this->last();
    $html[8]=$this->goPage();
    $fpage='';
    foreach($display as $index){
      $fpage.=$html[$index];
    }

    return $fpage;

  }


}