zulip/zerver/lib/mention.py

308 lines
11 KiB
Python

import functools
import re
from dataclasses import dataclass
from typing import Dict, List, Match, Optional, Set, Tuple
from django.conf import settings
from django.db.models import Q
from zerver.lib.users import get_inaccessible_user_ids
from zerver.models import UserGroup, UserProfile
from zerver.models.streams import get_linkable_streams
BEFORE_MENTION_ALLOWED_REGEX = r"(?<![^\s\'\"\(\{\[\/<])"
# Match multi-word string between @** ** or match any one-word
# sequences after @
MENTIONS_RE = re.compile(
rf"{BEFORE_MENTION_ALLOWED_REGEX}@(?P<silent>_?)(\*\*(?P<match>[^\*]+)\*\*)"
)
USER_GROUP_MENTIONS_RE = re.compile(
rf"{BEFORE_MENTION_ALLOWED_REGEX}@(?P<silent>_?)(\*(?P<match>[^\*]+)\*)"
)
topic_wildcards = frozenset(["topic"])
stream_wildcards = frozenset(["all", "everyone", "stream"])
@dataclass
class FullNameInfo:
id: int
full_name: str
is_active: bool
@dataclass
class UserFilter:
id: Optional[int]
full_name: Optional[str]
def Q(self) -> Q:
if self.full_name is not None and self.id is not None:
return Q(full_name__iexact=self.full_name, id=self.id)
elif self.id is not None:
return Q(id=self.id)
elif self.full_name is not None:
return Q(full_name__iexact=self.full_name)
else:
raise AssertionError("totally empty filter makes no sense")
@dataclass
class MentionText:
text: Optional[str]
is_topic_wildcard: bool
is_stream_wildcard: bool
@dataclass
class PossibleMentions:
mention_texts: Set[str]
message_has_topic_wildcards: bool
message_has_stream_wildcards: bool
class MentionBackend:
# Be careful about reuse: MentionBackend contains caches which are
# designed to only have the lifespan of a sender user (typically a
# single request).
#
# In particular, user_cache is not robust to message_sender
# within the lifetime of a single MentionBackend lifetime.
def __init__(self, realm_id: int) -> None:
self.realm_id = realm_id
self.user_cache: Dict[Tuple[int, str], FullNameInfo] = {}
self.stream_cache: Dict[str, int] = {}
def get_full_name_info_list(
self, user_filters: List[UserFilter], message_sender: Optional[UserProfile]
) -> List[FullNameInfo]:
result: List[FullNameInfo] = []
unseen_user_filters: List[UserFilter] = []
# Try to get messages from the user_cache first.
# This loop populates two lists:
# - results are the objects we pull from cache
# - unseen_user_filters are filters where need to hit the DB
for user_filter in user_filters:
# We expect callers who take advantage of our user_cache to supply both
# id and full_name in the user mentions in their messages.
if user_filter.id is not None and user_filter.full_name is not None:
user = self.user_cache.get((user_filter.id, user_filter.full_name), None)
if user is not None:
result.append(user)
continue
# BOO! We have to go the database.
unseen_user_filters.append(user_filter)
# Most of the time, we have to go to the database to get user info,
# unless our last loop found everything in the cache.
if unseen_user_filters:
q_list = [user_filter.Q() for user_filter in unseen_user_filters]
rows = (
UserProfile.objects.filter(
Q(realm_id=self.realm_id) | Q(email__in=settings.CROSS_REALM_BOT_EMAILS),
)
.filter(
functools.reduce(lambda a, b: a | b, q_list),
)
.only(
"id",
"full_name",
"is_active",
)
)
possible_mention_user_ids = [row.id for row in rows]
inaccessible_user_ids = get_inaccessible_user_ids(
possible_mention_user_ids, message_sender
)
user_list = [
FullNameInfo(id=row.id, full_name=row.full_name, is_active=row.is_active)
for row in rows
if row.id not in inaccessible_user_ids
]
# We expect callers who take advantage of our cache to supply both
# id and full_name in the user mentions in their messages.
for user in user_list:
self.user_cache[(user.id, user.full_name)] = user
result += user_list
return result
def get_stream_name_map(self, stream_names: Set[str]) -> Dict[str, int]:
if not stream_names:
return {}
result: Dict[str, int] = {}
unseen_stream_names: List[str] = []
for stream_name in stream_names:
if stream_name in self.stream_cache:
result[stream_name] = self.stream_cache[stream_name]
else:
unseen_stream_names.append(stream_name)
if unseen_stream_names:
q_list = {Q(name=name) for name in unseen_stream_names}
rows = (
get_linkable_streams(
realm_id=self.realm_id,
)
.filter(
functools.reduce(lambda a, b: a | b, q_list),
)
.values(
"id",
"name",
)
)
for row in rows:
self.stream_cache[row["name"]] = row["id"]
result[row["name"]] = row["id"]
return result
def user_mention_matches_topic_wildcard(mention: str) -> bool:
return mention in topic_wildcards
def user_mention_matches_stream_wildcard(mention: str) -> bool:
return mention in stream_wildcards
def extract_mention_text(m: Match[str]) -> MentionText:
text = m.group("match")
if text in topic_wildcards:
return MentionText(text=None, is_topic_wildcard=True, is_stream_wildcard=False)
if text in stream_wildcards:
return MentionText(text=None, is_topic_wildcard=False, is_stream_wildcard=True)
return MentionText(text=text, is_topic_wildcard=False, is_stream_wildcard=False)
def possible_mentions(content: str) -> PossibleMentions:
# mention texts can either be names, or an extended name|id syntax.
texts = set()
message_has_topic_wildcards = False
message_has_stream_wildcards = False
for m in MENTIONS_RE.finditer(content):
mention_text = extract_mention_text(m)
text = mention_text.text
if text:
texts.add(text)
if mention_text.is_topic_wildcard:
message_has_topic_wildcards = True
if mention_text.is_stream_wildcard:
message_has_stream_wildcards = True
return PossibleMentions(
mention_texts=texts,
message_has_topic_wildcards=message_has_topic_wildcards,
message_has_stream_wildcards=message_has_stream_wildcards,
)
def possible_user_group_mentions(content: str) -> Set[str]:
return {m.group("match") for m in USER_GROUP_MENTIONS_RE.finditer(content)}
def get_possible_mentions_info(
mention_backend: MentionBackend, mention_texts: Set[str], message_sender: Optional[UserProfile]
) -> List[FullNameInfo]:
if not mention_texts:
return []
user_filters = list()
name_re = r"(?P<full_name>.+)?\|(?P<mention_id>\d+)$"
for mention_text in mention_texts:
name_syntax_match = re.match(name_re, mention_text)
if name_syntax_match:
full_name = name_syntax_match.group("full_name")
mention_id = name_syntax_match.group("mention_id")
if full_name:
# For **name|id** mentions as mention_id
# cannot be null inside this block.
user_filters.append(UserFilter(full_name=full_name, id=int(mention_id)))
else:
# For **|id** syntax.
user_filters.append(UserFilter(full_name=None, id=int(mention_id)))
else:
# For **name** syntax.
user_filters.append(UserFilter(full_name=mention_text, id=None))
return mention_backend.get_full_name_info_list(user_filters, message_sender)
class MentionData:
def __init__(
self, mention_backend: MentionBackend, content: str, message_sender: Optional[UserProfile]
) -> None:
self.mention_backend = mention_backend
realm_id = mention_backend.realm_id
mentions = possible_mentions(content)
possible_mentions_info = get_possible_mentions_info(
mention_backend, mentions.mention_texts, message_sender
)
self.full_name_info = {row.full_name.lower(): row for row in possible_mentions_info}
self.user_id_info = {row.id: row for row in possible_mentions_info}
self.init_user_group_data(realm_id=realm_id, content=content)
self.has_stream_wildcards = mentions.message_has_stream_wildcards
self.has_topic_wildcards = mentions.message_has_topic_wildcards
def message_has_stream_wildcards(self) -> bool:
return self.has_stream_wildcards
def message_has_topic_wildcards(self) -> bool:
return self.has_topic_wildcards
def init_user_group_data(self, realm_id: int, content: str) -> None:
self.user_group_name_info: Dict[str, UserGroup] = {}
self.user_group_members: Dict[int, List[int]] = {}
user_group_names = possible_user_group_mentions(content)
if user_group_names:
for group in UserGroup.objects.filter(
realm_id=realm_id, name__in=user_group_names, is_system_group=False
).prefetch_related("direct_members"):
self.user_group_name_info[group.name.lower()] = group
self.user_group_members[group.id] = [m.id for m in group.direct_members.all()]
def get_user_by_name(self, name: str) -> Optional[FullNameInfo]:
# warning: get_user_by_name is not dependable if two
# users of the same full name are mentioned. Use
# get_user_by_id where possible.
return self.full_name_info.get(name.lower(), None)
def get_user_by_id(self, id: int) -> Optional[FullNameInfo]:
return self.user_id_info.get(id, None)
def get_user_ids(self) -> Set[int]:
"""
Returns the user IDs that might have been mentioned by this
content. Note that because this data structure has not parsed
the message and does not know about escaping/code blocks, this
will overestimate the list of user ids.
"""
return set(self.user_id_info.keys())
def get_user_group(self, name: str) -> Optional[UserGroup]:
return self.user_group_name_info.get(name.lower(), None)
def get_group_members(self, user_group_id: int) -> List[int]:
return self.user_group_members.get(user_group_id, [])
def get_stream_name_map(self, stream_names: Set[str]) -> Dict[str, int]:
return self.mention_backend.get_stream_name_map(stream_names)
def silent_mention_syntax_for_user(user_profile: UserProfile) -> str:
return f"@_**{user_profile.full_name}|{user_profile.id}**"