#! /usr/bin/python

import os
import sys

if len(sys.argv) < 6:
  print "Usage: dlscd_fixid OLD_PASSWD OLD_GROUP NEW_PASSWD NEW_GROUP DIR..."
  sys.exit(1)

old_passwd, old_group, new_passwd, new_group = sys.argv[1:5]
dirs = sys.argv[5:]

def makeIdDict(path):
  dict = {}
  f = open(path)
  try:
    for l in f:
      fields = l.split(':')
      try:
        dict[fields[0]] = int(fields[2])
      except:
        pass
  finally:
    f.close()
  return dict

def makeTranslationDict(old_dict, new_dict):
  dict = {}
  for key in old_dict.keys():
    if key in new_dict:
      old_value = old_dict[key]
      new_value = new_dict[key]
      if old_value != new_value:
        dict[old_value] = new_value
  return dict

def fixId(path, passwd_dict, group_dict):
  st = os.lstat(path)
  if st.st_uid in passwd_dict or st.st_gid in group_dict:
    new_uid = passwd_dict.get(st.st_uid, st.st_uid)
    new_gid = group_dict.get(st.st_gid, st.st_gid)
    os.chown(path, new_uid, new_gid)

old_passwd_dict = makeIdDict(old_passwd)
new_passwd_dict = makeIdDict(new_passwd)
old_group_dict = makeIdDict(old_group)
new_group_dict = makeIdDict(new_group)

passwd_dict = makeTranslationDict(old_passwd_dict, new_passwd_dict)
group_dict = makeTranslationDict(old_group_dict, new_group_dict)

if len(passwd_dict) == 0 and len(group_dict) == 0:
  sys.exit(0)

for dir in dirs:
  for dirpath, dirnames, filenames in os.walk(dir):
    for dirname in dirnames:
      path = os.path.join(dirpath, dirname)
      fixId(path, passwd_dict, group_dict)
    for filename in filenames:
      path = os.path.join(dirpath, filename)
      fixId(path, passwd_dict, group_dict)

sys.exit(0)