'''

Created on Jun 19, 2013

@author: Berlin

'''

import os

from ftplib import FTP

class FTPSync():

    def __init__(self, host, usr, psw, log_file):

        self.host = host

        self.usr = usr

        self.psw = psw

        self.log_file = log_file

    def __ConnectServer(self):

        try:

            self.ftp = FTP(self.host)

            self.ftp.login(self.usr, self.psw)

            self.ftp.set_pasv(False)

            return True

        except Exception:

            return False

    def __CloseServer(self):

        try:

            self.ftp.quit()

            return True

        except Exception:

            return False

    def __CheckSizeEqual(self, remoteFile, localFile):

        try:

            remoteFileSize = self.ftp.size(remoteFile)

            localFileSize = os.path.getsize(localFile)

            if localFileSize == remoteFileSize:

                return True

            else:

                return False

        except Exception:

            return None

    def __DownloadFile(self, remoteFile, localFile):

        try:

            self.ftp.cwd(os.path.dirname(remoteFile))

            f = open(localFile, 'wb')

            remoteFileName = 'RETR ' + os.path.basename(remoteFile)

            self.ftp.retrbinary(remoteFileName, f.write)

            if self.__CheckSizeEqual(remoteFile, localFile):

                self.log_file.write('The File is downloaded successfully to %s' + '\n' % localFile)

                return True

            else:

                self.log_file.write('The localFile %s size is not same with the remoteFile' + '\n' % localFile)

                return False

        except Exception:

            return False

    def __DownloadFolder(self, remoteFolder, localFolder):

        try:

            fileList = []

            self.ftp.retrlines('NLST', fileList.append)

            for remoteFile in fileList:

                localFile = os.path.join(localFolder, remoteFile)

                return self.__DownloadFile(remoteFile, localFile)

        except Exception:

            return False

    def SyncFromFTP(self, remoteFolder, localFolder):

        self.__DownloadFolder(remoteFolder, localFolder)

        self.log_file.close()

        self.__CloseServer()