#!/usr/bin/env python
# Copyright (C) WANG Cong, Apr. 2007
# GPLv2 applies.
#
# command:
#		./xylftppass add USERNAME PASSWORD
#

import sys, os
import string
#import md5

def findline(myfile, key):
	myfile.seek(0)
	lines = myfile.readlines()
	i = 1
	for line in lines:
		if key == line.split("::")[1]:
			return i
		else:
			i+=1
	return 0

def addline(myfile, newline):
	global default_mod
	uids = []
	names = []
	maxuid = 0
	myfile.seek(0)
	lines = myfile.readlines()
	for line in lines:
		if line == '\n':
			break
		temp = line.split("::")
		if not string.atoi(temp[0]) in uids:
			uids.append(string.atoi(temp[0]))
		if not temp[1] in names:
			names.append(temp[1])
	if names and (newline.split("::")[0] in names):
		print "User has already existed!"
		return -1
	if uids:
		uids.sort()
		maxuid = uids[len(uids)-1]
	else:
		maxuid = 1
	i = 0
	for i in range(maxuid+1):
		if i not in uids:
			break
	if i == maxuid:
		i+=1
	myfile.write("%s"%i+'::'+newline+'\n')
	return 0

def delline(myfile, num):
	myfile.seek(0)
	lines = myfile.readlines()
	del lines[num-1]
	myfile.seek(0)
	myfile.truncate()	#Note! This is used to empty the file.
	myfile.writelines(lines)
	return

def printline(myfile, num):
	myfile.seek(0)
	lines = myfile.readlines()
	tmplist = lines[num-1].split("::")
	del tmplist[3]
	print string.join(tmplist, '::')
	return

def changemod(myfile, n, newmod):
	myfile.seek(0)
	lines = myfile.readlines()
	tmplist = lines[n-1].split("::")
	tmplist[2] = newmod
	lines[n-1] = string.join(tmplist, '::')
	myfile.seek(0)
	myfile.truncate()
	myfile.writelines(lines)
	return

def changepass(myfile, n, newpass):
	myfile.seek(0)
	lines = myfile.readlines()
	tmplist = lines[n-1].split("::")
	#m = md5.new()
	#m.update(newpass)
	#tmplist[3] = m.digest()+'\n'	#IMO, the final '\n' should be added by hand.
	tmplist[3] = newpass+'\n'	#IMO, the final '\n' should be added by hand.
	lines[n-1] = string.join(tmplist, '::')
	myfile.seek(0)
	myfile.truncate()
	myfile.writelines(lines)
	return

def usage():
	print ''
	print sys.argv[0], 'add|del|show|passwd|chmod [options...]'
	print '''
	add $USERNAME $PASSWORD
	del $USERNAME
	show $USERNAME
	passwd $USERNAME $NEWPASSWD
	chmod $USERNAME $NEWMOD'''
	return

def main():
	username='anonymous'
	password=''
	file_name='./xylftp.pass'
	global default_mod
	cmds = ('add', 'del', 'chmod','show', 'passwd')
	if len(sys.argv) < 2 or not (sys.argv[1] in cmds):
		print 'Sign... Bad usage!'
		usage()
		return -1
	else:
		try:
			myfile = open(file_name, "rt+")
		except:
			print "Can't open file!"
			return -2
		else:
			if sys.argv[1] == 'add':
				if len(sys.argv) < 3:
					print 'Bad usage!'
					print '\'add\' command must be followed by a user name, but a password is optional.'
					myfile.close()
					return -1
				else:
					username = sys.argv[2]
					if len(sys.argv) == 4:
						password=sys.argv[3]
					#m = md5.new()
					#m.update(password)
					#addline(myfile, username+'::'+default_mod+'::'+m.digest())
					addline(myfile, username+'::'+default_mod+'::'+password)
			elif sys.argv[1] == 'del':
				if len(sys.argv) == 3:
					username = sys.argv[2]
				else:
					print "Bad usage!"
					print '\'del\' command must be followed by a user name.'
					myfile.close()
					return -1
				n = findline(myfile, username)
				if n == 0:
					print "No such user!"
				else:
					delline(myfile, n)
			elif sys.argv[1] == 'show':
				if len(sys.argv) != 3:
					print 'Bad usage!'
					print '\'show\' command must be followed by a user name.'
					myfile.close()
					return -1
				else:
					n = findline(myfile, sys.argv[2])
					if n != 0:
						printline(myfile, n)
					else:
						print "No such user!"
			elif sys.argv[1] == 'chmod':
				if len(sys.argv) != 4:
					print 'Bad usage!'
					print '\'chmod\' command must be followed by a user name and the new mode.'
					myfile.close()
					return -1
				else:
					n = findline(myfile, sys.argv[2])
					if n != 0:
						if sys.argv[3] not in ("rw", "r-", "-w", "--"):
							print "Invalid mode!" 
							myfile.close()
							return -1
						changemod(myfile, n, sys.argv[3])
					else:
						print "No such user!"

			elif sys.argv[1] == 'passwd':
				if len(sys.argv) != 4:
					print 'Bad usage!'
					print '\'passwd\' command must be followed by a user name and the new password of it.'
					myfile.close()
					return -1
				else:
					n = findline(myfile, sys.argv[2])
					if n != 0:
						changepass(myfile, n, sys.argv[3])
					else:
						print "No such user!"

			else:
				myfile.close()
				print "No such command."
				return -1
		myfile.close()
		return 0

default_mod = 'rw'
ret = main()
sys.exit(ret)