maubot_reactbot/reactbot/simplepattern.py
2019-06-23 13:43:10 +03:00

62 lines
2.4 KiB
Python

# reminder - A maubot plugin that reacts to messages that match predefined rules.
# Copyright (C) 2019 Tulir Asokan
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
from typing import Callable, List, Optional
import re
class BlankMatch:
@staticmethod
def groups() -> List[str]:
return []
class SimplePattern:
_ptm = BlankMatch()
matcher: Callable[[str], bool]
ignorecase: bool
def __init__(self, matcher: Callable[[str], bool], ignorecase: bool) -> None:
self.matcher = matcher
self.ignorecase = ignorecase
def search(self, val: str) -> BlankMatch:
if self.ignorecase:
val = val.lower()
if self.matcher(val):
return self._ptm
@staticmethod
def compile(pattern: str, flags: re.RegexFlag = re.RegexFlag(0), force_raw: bool = False
) -> Optional['SimplePattern']:
ignorecase = flags == re.IGNORECASE
s_pattern = pattern.lower() if ignorecase else pattern
esc = ""
if not force_raw:
esc = re.escape(pattern)
first, last = pattern[0], pattern[-1]
if first == '^' and last == '$' and (force_raw or esc == f"\\^{pattern[1:-1]}\\$"):
s_pattern = s_pattern[1:-1]
return SimplePattern(lambda val: val == s_pattern, ignorecase=ignorecase)
elif first == '^' and (force_raw or esc == f"\\^{pattern[1:]}"):
s_pattern = s_pattern[1:]
return SimplePattern(lambda val: val.startswith(s_pattern), ignorecase=ignorecase)
elif last == '$' and (force_raw or esc == f"{pattern[:-1]}\\$"):
s_pattern = s_pattern[:-1]
return SimplePattern(lambda val: val.endswith(s_pattern), ignorecase=ignorecase)
elif force_raw or esc == pattern:
return SimplePattern(lambda val: s_pattern in val, ignorecase=ignorecase)
return None