import os, json
from flask import make_response, send_from_directory, request
from flask.helpers import send_file

#定义基类
class DocumentOper():
    #构造函数，类被初始化时调用
    def __init__(self,fileName="", filePath="", fileType=""):
        print("base init:",fileName,filePath,  fileType)
        self.setFileName(fileName)
        self.setFilePath(filePath)
        self.setFileType(fileType)
        self.setFullPath()
     
     #设置文件名   
    def setFileName(self, fileName):
        #判断 fileName的值 是不是字符串
        if not isinstance(fileName, str):
            raise Exception('fileName must be string.')
        self.__fileName = fileName
    
    #设置文件路径
    def setFilePath(self, filePath):
        if type(filePath) !=str:
            raise Exception('filePath must be string.')
        self.__filePath = filePath
    
    #设置文件完整的路径  
    def setFullPath(self):
        #upload/docx/xx.docx
        #return self.__filePath+"/"+self.__fileName
        return "%s/%s"%(self.__filePath, self.__fileName)
    
    def setFileType(self, fileType):
        if fileType not in ('docx','xlsx','pptx','txt'):
            raise Exception('不支持的文件格式.')
        
        #使用字典形式来识别不同的文件格式，因为python中没有switch..case语句
        mimeTypes = {
            'docx': 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
            'xlsx': 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
            }       
        self.__fileType = fileType
        self.__mimeType = mimeTypes[fileType]
        
    
    def downloadFile(self): #下载的方法,Blob形式
        directory = os.getcwd() #获取当前程序的工作路径
        mFilePath = directory.replace('\\','/')+"/"+self.__filePath
        #response = send_file(self.setFullPath(), mimetype=self.__mimeType,  
        #                       attachment_filename= self.__fileName, as_attachment=True)        
        response = make_response(send_from_directory(mFilePath,self.__fileName, as_attachment=True)) 

        return response    
    
    #生成操作，只定义不实现，由各派生类自己完成
    def export(self, exportData):
        try:
            pass
        except :
            pass