<?php
class Upload{
  private $filepath = './upload'; //上传目录
  private $tmpPath; //PHP文件临时目录
  private $blobNum; //第几个文件块
  private $totalBlobNum; //文件块总数
  private $fileName; //文件名
 
  public function __construct($tmpPath,$blobNum,$totalBlobNum,$fileName){
    $this->tmpPath = $tmpPath;
    $this->blobNum = $blobNum;
    $this->totalBlobNum = $totalBlobNum;
    $this->fileName = $fileName;
     
    $this->moveFile();
    $this->fileMerge();
  }
   
  //判断是否是最后一块，如果是则进行文件合成并且删除文件块
  private function fileMerge(){
    if($this->blobNum == $this->totalBlobNum){
      $blob = '';
      for($i=1; $i<= $this->totalBlobNum; $i++){
        $blob .= file_get_contents($this->filepath.'/'. $this->fileName.'__'.$i);
      }
      file_put_contents($this->filepath.'/'. $this->fileName,$blob);
      $this->deleteFileBlob();
    }
  }
   
  //删除文件块
  private function deleteFileBlob(){
    for($i=1; $i<= $this->totalBlobNum; $i++){
      @unlink($this->filepath.'/'. $this->fileName.'__'.$i);
    }
  }
   
  //移动文件
  private function moveFile(){
    $this->touchDir();
    $filename = $this->filepath.'/'. $this->fileName.'__'.$this->blobNum;
    move_uploaded_file($this->tmpPath,$filename);
  }
   
  //API返回数据
  public function apiReturn(){
    if($this->blobNum == $this->totalBlobNum){
        if(file_exists($this->filepath.'/'. $this->fileName)){
          $data['code'] = 2;
          $data['msg'] = 'success';
          $data['file_path'] = 'http://'.$_SERVER['HTTP_HOST'].dirname($_SERVER['DOCUMENT_URI']).str_replace('.','',$this->filepath).'/'. $this->fileName;
        }
    }else{
        if(file_exists($this->filepath.'/'. $this->fileName.'__'.$this->blobNum)){
          $data['code'] = 1;
          $data['msg'] = 'waiting for all';
          $data['file_path'] = '';
        }
    }
    header('Content-type: application/json');
    echo json_encode($data);
  }
   
  //建立上传文件夹
  private function touchDir(){
    if(!file_exists($this->filepath)){
      return mkdir($this->filepath);
    }
  }
}
 
//实例化并获取系统变量传参
$upload = new Upload($_FILES['file']['tmp_name'],$_POST['blob_num'],$_POST['total_blob_num'],$_POST['file_name']);
//调用方法，返回结果
$upload->apiReturn();