#coding:utf-8

import ftplib
import time
import os.path

FTP_USER = ''
FTP_PWD = ''

REMOTE_HOST = 'ftp.debian.org'
REMOTE_DIR = 'debian/tools'
REMOTE_FILES = ('loadlin.exe', 'loadlin.txt')

LOCAL_DIR = 'D:'
LOCAL_FILES = ('loadlin.exe', 'loadlin.txt')

need_enter = False

try:
    print('connect to %s... ...' % (REMOTE_HOST,))
    ftp = ftplib.FTP(REMOTE_HOST)
    print('login to %s... ...' % (REMOTE_HOST,))
    ftp.login(FTP_USER, FTP_PWD)
    print(ftp.getwelcome())
    print('open %s/%s' % (REMOTE_HOST, REMOTE_DIR))
    ftp.cwd(REMOTE_DIR)

    for remote_file in REMOTE_FILES:
        #remote file
        remote_filepath = REMOTE_HOST + '/' + REMOTE_DIR + '/' + remote_file
        #local file
        idx = REMOTE_FILES.index(remote_file)
        local_file = LOCAL_FILES[idx]
        local_filepath = LOCAL_DIR + '/' + local_file
        #
        need_copy = False
        
        try:
            #remote last time
            cmd_out = ftp.sendcmd('MDTM ' + remote_file)
            status, mdtm = cmd_out.split(' ', 2)
            #print('%s/%s/%s: %s, %s' % (REMOTE_HOST, REMOTE_DIR, remote_file, status, mdtm))

            #remote last time
            rlt = time.strptime(mdtm, '%Y%m%d%H%M%S')
            
            #local last datetime
            llt = time.gmtime(os.path.getmtime(local_filepath))

            #compare the file was last modified time
            need_copy = llt < rlt

            #Compare file size
            if not need_copy:
                cmd_out = ftp.sendcmd('SIZE ' + remote_file)
                status, _size = cmd_out.split(' ', 2)

                rs = int(_size)

                ls = os.path.getsize(local_filepath)
                need_copy = rs != ls
                
        except ftplib.error_perm as e:
            print(e)
        except os.error as e:
            print(e)
            need_copy = True

        #copy file
        if need_copy:
            print('copy file %s to %s... ...' % (remote_filepath, local_filepath))
            ftp.retrbinary('RETR ' + remote_file, open(local_filepath, 'wb').write)
        
except ftplib.all_errors as e:
    need_enter = True
    print(e)
    raise
else:
    pass
finally:
    try:
        ftp
    except NameError:
        pass
    else:
        print('close connection')
        ftp.quit()

if need_enter:
    raw_input('ENTER to continue')