python/samba/netcmd/validators.py

   1 # Unix SMB/CIFS implementation.
   2 #
   3 # validators
   4 #
   5 # Copyright (C) Catalyst.Net Ltd. 2023
   6 #
   7 # Written by Rob van der Linde <rob@catalyst.net.nz>
   8 #
   9 # This program is free software; you can redistribute it and/or modify
  10 # it under the terms of the GNU General Public License as published by
  11 # the Free Software Foundation; either version 3 of the License, or
  12 # (at your option) any later version.
  13 #
  14 # This program is distributed in the hope that it will be useful,
  15 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 # GNU General Public License for more details.
  18 #
  19 # You should have received a copy of the GNU General Public License
  20 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 #
  22
  23 from abc import ABCMeta, abstractmethod
  24
  25
  26 class ValidationError(Exception):
  27     pass
  28
  29
  30 class Validator(metaclass=ABCMeta):
  31
  32     @abstractmethod
  33     def __call__(self, field, value):
  34         pass
  35
  36
  37 class Range(Validator):
  38     """Checks if the value is within range min ... max."""
  39
  40     def __init__(self, min=None, max=None):
  41         if min is None and max is None:
  42             raise ValueError("Range without a min and max doesn't make sense.")
  43
  44         self.min = min
  45         self.max = max
  46
  47     def __call__(self, field, value):
  48         """Check if value is within the range min ... max.
  49
  50         It is possible to omit min, or omit max, in which case a more
  51         tailored error message is returned.
  52         """
  53         if self.min is not None and self.max is None:
  54             if value < self.min:
  55                 raise ValidationError(f"{field} must be at least {self.min}")
  56
  57         elif self.min is None and self.max is not None:
  58             if value > self.max:
  59                 raise ValidationError(
  60                     f"{field} cannot be greater than {self.max}")
  61
  62         elif self.min is not None and self.max is not None:
  63             if value < self.min or value > self.max:
  64                 raise ValidationError(
  65                     f"{field} must be between {self.min} and {self.max}")
  66
  67
  68 class OneOf(Validator):
  69     """Checks if the value is in a list of possible choices."""
  70
  71     def __init__(self, choices):
  72         self.choices = sorted(choices)
  73
  74     def __call__(self, field, value):
  75         if value not in self.choices:
  76             allowed_choices = ", ".join(self.choices)
  77             raise ValidationError(f"{field} must be one of: {allowed_choices}")