Files
LangBot/src/langbot/pkg/platform/sources/mattermost.py
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376 lines
15 KiB
Python

from __future__ import annotations
import asyncio
import json
import re
import typing
from urllib.parse import urlsplit, urlunsplit
import aiohttp
import langbot_plugin.api.definition.abstract.platform.adapter as abstract_platform_adapter
import langbot_plugin.api.definition.abstract.platform.event_logger as abstract_platform_logger
import langbot_plugin.api.entities.builtin.platform.entities as platform_entities
import langbot_plugin.api.entities.builtin.platform.events as platform_events
import langbot_plugin.api.entities.builtin.platform.message as platform_message
_MATTERMOST_MAX_POST_LENGTH = 16_383
_MENTION_BOUNDARY = r'(?<![\w.-])@{username}(?![\w.-])'
def _normalize_server_url(server_url: str) -> str:
"""Return a validated Mattermost server URL without a trailing slash."""
url = server_url.strip().rstrip('/')
parsed = urlsplit(url)
if parsed.scheme not in {'http', 'https'} or not parsed.netloc:
raise ValueError('Mattermost server_url must be an absolute HTTP(S) URL')
return url
def _websocket_url(server_url: str) -> str:
parsed = urlsplit(server_url)
scheme = 'wss' if parsed.scheme == 'https' else 'ws'
return urlunsplit((scheme, parsed.netloc, f'{parsed.path}/api/v4/websocket', '', ''))
class MattermostMessageConverter(abstract_platform_adapter.AbstractMessageConverter):
"""Translate Mattermost post text to and from LangBot message chains."""
@staticmethod
async def yiri2target(message_chain: platform_message.MessageChain) -> str:
parts: list[str] = []
for component in message_chain:
if isinstance(component, platform_message.Plain):
parts.append(component.text)
elif isinstance(component, platform_message.Image) and component.url:
# Mattermost renders image URLs in Markdown messages.
parts.append(component.url)
elif isinstance(component, platform_message.File) and component.url:
parts.append(component.url)
return ''.join(parts)
@staticmethod
async def target2yiri(post: dict, bot_username: str) -> platform_message.MessageChain:
text = str(post.get('message') or '')
components: list[typing.Any] = [
platform_message.Source(
id=str(post.get('id') or ''),
time=float(post.get('create_at') or 0) / 1000,
)
]
if bot_username:
mention_pattern = re.compile(_MENTION_BOUNDARY.format(username=re.escape(bot_username)), re.IGNORECASE)
if mention_pattern.search(text):
components.append(platform_message.At(target=bot_username))
text = mention_pattern.sub('', text).strip()
if text:
components.append(platform_message.Plain(text=text))
return platform_message.MessageChain(components)
class MattermostEventConverter(abstract_platform_adapter.AbstractEventConverter):
@staticmethod
async def yiri2target(event: platform_events.MessageEvent) -> dict:
return event.source_platform_object
@staticmethod
async def target2yiri(
post: dict,
channel: dict,
sender_name: str,
bot_username: str,
) -> platform_events.MessageEvent:
message_chain = await MattermostMessageConverter.target2yiri(post, bot_username)
timestamp = float(post.get('create_at') or 0) / 1000
sender_id = str(post.get('user_id') or '')
channel_type = channel.get('type')
if channel_type == 'D':
return platform_events.FriendMessage(
sender=platform_entities.Friend(id=sender_id, nickname=sender_name or sender_id, remark=''),
message_chain=message_chain,
time=timestamp,
source_platform_object={'post': post, 'channel': channel},
)
return platform_events.GroupMessage(
sender=platform_entities.GroupMember(
id=sender_id,
member_name=sender_name or sender_id,
permission=platform_entities.Permission.Member,
group=platform_entities.Group(
id=str(post.get('channel_id') or ''),
name=str(channel.get('display_name') or channel.get('name') or post.get('channel_id') or ''),
permission=platform_entities.Permission.Member,
),
special_title='',
),
message_chain=message_chain,
time=timestamp,
source_platform_object={'post': post, 'channel': channel},
)
class MattermostAdapter(abstract_platform_adapter.AbstractMessagePlatformAdapter):
"""Mattermost Bot Account adapter using the v4 REST and WebSocket APIs."""
server_url: str = ''
access_token: str = ''
session: aiohttp.ClientSession | None = None
listeners: dict[typing.Type[platform_events.Event], typing.Callable] = {}
channel_cache: dict[str, dict] = {}
stream_post_ids: dict[str, str] = {}
bot_username: str = ''
_running: bool = False
message_converter: MattermostMessageConverter = MattermostMessageConverter()
event_converter: MattermostEventConverter = MattermostEventConverter()
def __init__(self, config: dict, logger: abstract_platform_logger.AbstractEventLogger):
server_url = _normalize_server_url(str(config.get('server_url') or ''))
access_token = str(config.get('access_token') or '').strip()
if not access_token:
raise ValueError('Mattermost adapter requires an access_token')
super().__init__(
config=config,
logger=logger,
server_url=server_url,
access_token=access_token,
bot_account_id='',
session=None,
listeners={},
channel_cache={},
stream_post_ids={},
bot_username='',
_running=False,
)
async def _get_session(self) -> aiohttp.ClientSession:
if self.session is None or self.session.closed:
self.session = aiohttp.ClientSession(
headers={'Authorization': f'Bearer {self.access_token}'},
raise_for_status=False,
)
return self.session
async def _api_request(
self,
method: str,
path: str,
*,
payload: dict | None = None,
) -> dict:
session = await self._get_session()
async with session.request(method, f'{self.server_url}/api/v4{path}', json=payload) as response:
raw_body = await response.text()
if response.status >= 400:
# Mattermost returns a useful JSON error, but never include request headers/tokens in errors.
try:
error = json.loads(raw_body).get('message', raw_body)
except json.JSONDecodeError:
error = raw_body
raise RuntimeError(f'Mattermost API {method} {path} failed ({response.status}): {error}')
if not raw_body:
return {}
return json.loads(raw_body)
async def _load_bot_identity(self) -> None:
user = await self._api_request('GET', '/users/me')
self.bot_account_id = str(user.get('id') or '')
self.bot_username = str(user.get('username') or '')
if not self.bot_account_id:
raise RuntimeError('Mattermost API did not return a bot user ID')
async def _get_channel(self, channel_id: str) -> dict:
if channel_id not in self.channel_cache:
self.channel_cache[channel_id] = await self._api_request('GET', f'/channels/{channel_id}')
return self.channel_cache[channel_id]
async def _post_message(self, channel_id: str, text: str, root_id: str = '') -> dict:
if not text:
return {}
if len(text) > _MATTERMOST_MAX_POST_LENGTH:
raise ValueError(f'Mattermost messages cannot exceed {_MATTERMOST_MAX_POST_LENGTH} characters')
payload = {'channel_id': channel_id, 'message': text}
if root_id:
payload['root_id'] = root_id
return await self._api_request('POST', '/posts', payload=payload)
async def _get_direct_channel_id(self, user_id: str) -> str:
if not self.bot_account_id:
await self._load_bot_identity()
channel = await self._api_request(
'POST',
'/channels/direct',
payload={'user_ids': [self.bot_account_id, user_id]},
)
channel_id = str(channel.get('id') or '')
if not channel_id:
raise RuntimeError('Mattermost did not return a direct-message channel ID')
self.channel_cache[channel_id] = channel
return channel_id
async def send_message(self, target_type: str, target_id: str, message: platform_message.MessageChain):
if target_type not in {'person', 'group'}:
raise ValueError("Mattermost target_type must be 'person' or 'group'")
text = await self.message_converter.yiri2target(message)
channel_id = str(target_id)
if target_type == 'person':
channel_id = await self._get_direct_channel_id(channel_id)
await self._post_message(channel_id, text)
async def reply_message(
self,
message_source: platform_events.MessageEvent,
message: platform_message.MessageChain,
quote_origin: bool = False,
):
source = await self.event_converter.yiri2target(message_source)
post = source['post']
text = await self.message_converter.yiri2target(message)
# A message received inside a Mattermost thread must remain in that thread. When
# quote_origin is requested, make the response a reply to the source root post.
root_id = str(post.get('root_id') or '')
if quote_origin and not root_id:
root_id = str(post.get('id') or '')
await self._post_message(str(post['channel_id']), text, root_id)
async def create_message_card(self, message_id: str, event: platform_events.MessageEvent) -> bool:
source = await self.event_converter.yiri2target(event)
post = source['post']
root_id = str(post.get('root_id') or post.get('id') or '')
created = await self._post_message(str(post['channel_id']), 'Thinking…', root_id)
if created.get('id'):
self.stream_post_ids[str(message_id)] = str(created['id'])
return True
return False
async def reply_message_chunk(
self,
message_source: platform_events.MessageEvent,
bot_message,
message: platform_message.MessageChain,
quote_origin: bool = False,
is_final: bool = False,
):
response_id = str(bot_message.resp_message_id)
text = await self.message_converter.yiri2target(message)
if not text:
return
post_id = self.stream_post_ids.get(response_id)
if post_id:
await self._api_request('PUT', f'/posts/{post_id}', payload={'id': post_id, 'message': text})
else:
source = await self.event_converter.yiri2target(message_source)
post = source['post']
root_id = str(post.get('root_id') or '')
if quote_origin and not root_id:
root_id = str(post.get('id') or '')
created = await self._post_message(str(post['channel_id']), text, root_id)
post_id = str(created.get('id') or '')
if post_id:
self.stream_post_ids[response_id] = post_id
if is_final and getattr(bot_message, 'tool_calls', None) is None:
self.stream_post_ids.pop(response_id, None)
async def is_stream_output_supported(self) -> bool:
return bool(self.config.get('enable_stream_reply', True))
def register_listener(
self,
event_type: typing.Type[platform_events.Event],
callback: typing.Callable[
[platform_events.Event, abstract_platform_adapter.AbstractMessagePlatformAdapter], typing.Awaitable[None]
],
):
self.listeners[event_type] = callback
def unregister_listener(
self,
event_type: typing.Type[platform_events.Event],
callback: typing.Callable[
[platform_events.Event, abstract_platform_adapter.AbstractMessagePlatformAdapter], typing.Awaitable[None]
],
):
self.listeners.pop(event_type, None)
async def _dispatch_post(self, payload: dict) -> None:
data = payload.get('data') or {}
try:
post = json.loads(data.get('post') or '{}')
except (TypeError, json.JSONDecodeError):
await self.logger.error('Mattermost received a posted event with an invalid post payload')
return
if not post or str(post.get('user_id') or '') == self.bot_account_id:
return
channel_id = str(post.get('channel_id') or '')
if not channel_id:
return
try:
channel = await self._get_channel(channel_id)
event = await self.event_converter.target2yiri(
post,
channel,
str(data.get('sender_name') or post.get('user_id') or ''),
self.bot_username,
)
callback = self.listeners.get(type(event))
if callback:
result = callback(event, self)
if asyncio.iscoroutine(result):
await result
except Exception as exc:
await self.logger.error(f'Error handling Mattermost post: {exc}')
async def _run_websocket_once(self) -> None:
session = await self._get_session()
async with session.ws_connect(_websocket_url(self.server_url), heartbeat=30) as websocket:
await websocket.send_json(
{
'seq': 1,
'action': 'authentication_challenge',
'data': {'token': self.access_token},
}
)
async for message in websocket:
if message.type == aiohttp.WSMsgType.TEXT:
try:
payload = json.loads(message.data)
except json.JSONDecodeError:
continue
if payload.get('event') == 'posted':
await self._dispatch_post(payload)
elif message.type in {aiohttp.WSMsgType.CLOSED, aiohttp.WSMsgType.CLOSE, aiohttp.WSMsgType.ERROR}:
break
async def run_async(self):
self._running = True
await self._load_bot_identity()
await self.logger.info(f'Mattermost bot connected: @{self.bot_username} ({self.bot_account_id})')
retry_delay = 1
while self._running:
try:
await self._run_websocket_once()
retry_delay = 1
except asyncio.CancelledError:
raise
except Exception as exc:
if self._running:
await self.logger.error(f'Mattermost WebSocket disconnected: {exc}')
await asyncio.sleep(retry_delay)
retry_delay = min(retry_delay * 2, 30)
async def kill(self) -> bool:
self._running = False
if self.session and not self.session.closed:
await self.session.close()
return True