import string, re, sys, os, crypt

class Acl:

    def __init__(self, root='.', file='etc/passwd'):
        self.acl_root = root
        self.acl_file = file
        self.acl_list = {}
        if not os.path.isfile('%s/%s' % (self.acl_root, self.acl_file)):
            file = open('%s/%s' % (self.acl_root, self.acl_file), 'w')
            file.close()
        return

    def acl_init(self):
        file = open('%s/%s' % (self.acl_root, self.acl_file), 'r')
        lines = file.readlines()
        file.close()
        self.acl_list = {}
        for line in lines:
            list = (line[:-1]).split('\t')
            self.acl_list[list[0]] = list
        return

    def acl_getuser(self, username):
        file = open('%s/%s' % (self.acl_root, self.acl_file), 'r')
        lines = file.readlines()
        file.close()
        username = '%s\t' % (username)
        for line in lines:
            if line.startswith(username):
                return (line[:-1]).split('\t')
        return None

    def acl_adduser(self, username, password='', attr=[]):
        if self.acl_getuser(username):
            return 0
        if not username or username != re.sub('[\W_]', '_', username):
            return 0
        file = open('%s/%s' % (self.acl_root, self.acl_file), 'a')
        file.write('%s\t%s\t%s\n' % (username, crypt.crypt(password, 'xx'), string.join(map(str, attr), '\t')))
        file.close()
        return 1

    def acl_deluser(self, username):
        if not self.acl_getuser(username):
            return 0
        temp = open('%s/%s.%s' % (self.acl_root, self.acl_file, os.getpid()), 'w')
        file = open('%s/%s' % (self.acl_root, self.acl_file), 'r')
        lines = file.readlines()
        file.close()
        username = '%s\t' % (username)
        for line in lines:
            if not line.startswith(username):
                temp.write(line)
        temp.close()
        pid = os.getpid()
        os.rename('%s/%s.%s' % (self.acl_root, self.acl_file, pid), '%s/%s' % (self.acl_root, self.acl_file))
        if os.path.isfile('%s/%s.%s' % (self.acl_root, self.acl_file, pid)):
            os.remove('%s/%s.%s' % (self.acl_root, self.acl_file, pid))
            return 0
        return 1

    def acl_listuser(self, pattern='.*'):
        file = open('%s/%s' % (self.acl_root, self.acl_file), 'r')
        lines = file.readlines()
        file.close()
        list = []
        pattern = '%s\t.*' % (pattern)
        for line in lines:
            if line:
                if re.match(pattern, line):
                    list.append((line[:-1]).split('\t'))
        return list

    def acl_passwd(self, username, password):
        user = self.acl_getuser(username)
        if not user:
            return 0
        if not self.acl_deluser(username):
            return 0
        if not self.acl_adduser(username, password, user[2:]):
            return 0
        return 1

    def acl_auth(self, username, password):
        if self.acl_list:
            user = self.acl_list.get(username, None)
            if user:
                confirm = user[1]
                if confirm == crypt.crypt(password, 'xx'):
                    return user[:1] + user[2:]
                return None
        user = self.acl_getuser(username)
        if user:
            confirm = user[1]
            if confirm == crypt.crypt(password, 'xx'):
                return user[:1] + user[2:]
        return None