mautrix-telegram/mautrix_telegram/formatter/from_matrix/__init__.py

111 lines
3.8 KiB
Python

# mautrix-telegram - A Matrix-Telegram puppeting bridge
# Copyright (C) 2021 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 __future__ import annotations
import re
from telethon import TelegramClient
from telethon.helpers import add_surrogate, del_surrogate, strip_text
from telethon.tl.types import MessageEntityItalic, TypeMessageEntity
from mautrix.types import MessageEventContent, RoomID
from ...db import Message as DBMessage
from ...types import TelegramID
from .parser import MatrixParser
command_regex = re.compile(r"^!([A-Za-z0-9@]+)")
not_command_regex = re.compile(r"^\\(![A-Za-z0-9@]+)")
MAX_LENGTH = 4096
CUTOFF_TEXT = " [message cut]"
CUT_MAX_LENGTH = MAX_LENGTH - len(CUTOFF_TEXT)
class FormatError(Exception):
pass
async def matrix_reply_to_telegram(
content: MessageEventContent, tg_space: TelegramID, room_id: RoomID | None = None
) -> TelegramID | None:
event_id = content.get_reply_to()
if not event_id:
return
content.trim_reply_fallback()
message = await DBMessage.get_by_mxid(event_id, room_id, tg_space)
if message:
return message.tgid
return None
async def matrix_to_telegram(
client: TelegramClient, *, text: str | None = None, html: str | None = None
) -> tuple[str, list[TypeMessageEntity]]:
if html is not None:
return await _matrix_html_to_telegram(client, html)
elif text is not None:
return _matrix_text_to_telegram(text)
else:
raise ValueError("text or html must be provided to convert formatting")
async def _matrix_html_to_telegram(
client: TelegramClient, html: str
) -> tuple[str, list[TypeMessageEntity]]:
try:
html = command_regex.sub(r"<command>\1</command>", html)
html = html.replace("\t", " " * 4)
html = not_command_regex.sub(r"\1", html)
parsed = await MatrixParser(client).parse(add_surrogate(html))
text, entities = _cut_long_message(parsed.text, parsed.telegram_entities)
text = del_surrogate(strip_text(text, entities))
return text, entities
except Exception as e:
raise FormatError(f"Failed to convert Matrix format: {html}") from e
def _cut_long_message(
message: str, entities: list[TypeMessageEntity]
) -> tuple[str, list[TypeMessageEntity]]:
if len(message) > MAX_LENGTH:
message = message[0:CUT_MAX_LENGTH] + CUTOFF_TEXT
new_entities = []
for entity in entities:
if entity.offset > CUT_MAX_LENGTH:
continue
if entity.offset + entity.length > CUT_MAX_LENGTH:
entity.length = CUT_MAX_LENGTH - entity.offset
new_entities.append(entity)
new_entities.append(MessageEntityItalic(CUT_MAX_LENGTH, len(CUTOFF_TEXT)))
entities = new_entities
return message, entities
def _matrix_text_to_telegram(text: str) -> tuple[str, list[TypeMessageEntity]]:
text = command_regex.sub(r"/\1", text)
text = text.replace("\t", " " * 4)
text = not_command_regex.sub(r"\1", text)
entities = []
surrogated_text = add_surrogate(text)
if len(surrogated_text) > MAX_LENGTH:
surrogated_text, entities = _cut_long_message(surrogated_text, entities)
text = del_surrogate(surrogated_text)
return text, entities