client.py

'''111

Script for client side
@author: hao
'''
import protocol
import config
from socket import *
import os

class client:           
    fileList=[] # list to store the file information

    #Constructor: load client configuration from config file
    def __init__(self):
        self.serverName, self.serverPort, self.clientPort, self.downloadPath = config.config().readClientConfig()

    # Function to produce user menu 
    def printMenu(self):
        print("Welcome to simple file sharing system!")
        print("Please select operations from menu")
        print("--------------------------------------")
        print("1. Review the List of Available Files")
        print("2. Download File")
        print("3. Upload a file to the Server")
        print("4. Quit")

    # Function to get user selection from the menu
    def getUserSelection(self):       
        ans=0
        # only accept option 1-4
        while ans>4 or ans<1:
            self.printMenu()
            try:
                ans=int(input())
            except:
                ans=0
            if (ans<=4) and (ans>=1):
                return ans
            print("Invalid Option")
#^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    # Build connection to server
    def connect(self):
        serverName = self.serverName
        serverPort = self.serverPort
        clientSocket = socket(AF_INET, SOCK_STREAM)
        clientSocket.connect((serverName,serverPort))
        return clientSocket

    # Get file list from server by sending the request
    def getFileList(self):
        mySocket=self.connect()
        mySocket.send(protocol.prepareMsg(protocol.HEAD_REQUEST," "))
        header, msg=protocol.decodeMsg(mySocket.recv(1024).decode())
        mySocket.close()
        if(header==protocol.HEAD_LIST): 
            files=msg.split(",")
            self.fileList=[]
            for f in files:
                self.fileList.append(f)
        else:
            print ("Error: cannnot get file list!")
#==========================================================================
    def getFileListFromClient(self):
        files= os.listdir(self.downloadPath)
        self.fileList=[]
        for f in files:
            self.fileList.append(f)
#==========================================================================

    # function to print files in the list with the file number
    def printFileList(self):
        count=0
        for f in self.fileList:
            count+=1
            print('{:<3d}{}'.format(count,f))

    # Function to select the file from file list by file number,
    # return the file name user selected
    def selectDownloadFile(self):
        if(len(self.fileList)==0):
            self.getFileList()
        ans=-1
        while ans<0 or ans>len(self.fileList)+1:
            self.printFileList()
            print("Please select the file you want to download from the list (enter the number of files):")
            try:
                ans=int(input())
            except:
                ans=-1
            if (ans>0) and (ans<len(self.fileList)+1):
                return self.fileList[ans-1]
            print("Invalid number")
#--------------------------------------------------------------------------------------------------------------
    def selectUploadFile(self):
        if(len(self.fileList)==0):
            self.getFileListFromClient()
        ans=-1
        while ans<0 or ans>len(self.fileList)+1:
            self.printFileList()
            print("Please select the file you want to upload from the list (enter the number of files):")
            try:
                ans=int(input())
            except:
                ans=-1
            if (ans>0) and (ans<len(self.fileList)+1):
                return self.fileList[ans-1]
            print("Invalid number")
#------------------------------------------------------------------------------------------------------------------
    # Function to send download request to server and wait for file data
    def downloadFile(self,fileName):
        mySocket=self.connect()
        mySocket.send(protocol.prepareMsg(protocol.HEAD_DOWNLOAD, fileName))
        with open(self.downloadPath+"/"+fileName, 'wb') as f:
            print ('file opened')
            while True:
                #print('receiving data...')
                data = mySocket.recv(1024)
                #print('data=%s', (data))
                if not data:
                     break
            # write data to a file
                f.write(data)
        print(fileName+" has been downloaded!")
        mySocket.close()
#==========================================================================================
    def uploadFile(self,fileName):
        mySocket=self.connect()
        mySocket.send(protocol.prepareMsg(protocol.HEAD_UPLOAD, fileName))
        f = open(self.downloadPath+"/"+fileName,'rb')
        l = f.read(1024) # each time we only send 1024 bytes of data
        while (l):
            mySocket.send(l)
            l = f.read(1024)
                
        print(fileName+" has been Uploaded!")
        mySocket.close()
#============================================================================================
    # Main logic of the client, start the client application
    def start(self):
        opt=0
        while opt!=4:
            opt=self.getUserSelection()
            if opt==1:
                if(len(self.fileList)==0):
                    self.getFileList()
                self.printFileList()                  
            elif opt==2:
                self.downloadFile(self.selectDownloadFile())
            elif opt==3:
                self.getFileListFromClient()
                self.uploadFile(self.selectUploadFile())
            else:
                pass
                
def main():
    c=client()
    c.start()
main()