Private
Public Access
ksmithandClaude Sonnet 5
760d2cf5dd
Slack/Discord-style link unfurling: the first http(s) URL in a message's content gets a small preview card (title/description/image/site name) fetched from the page's Open Graph tags. Backend: - Message.preview_url (extracted at create/edit time, cheap regex, no I/O) points at a link_previews cache row keyed by URL -- the same URL posted in different messages/rooms fetches once, and a failed fetch is cached too so a dead URL isn't retried on every reference. - The actual fetch runs in a background asyncio.create_task from broadcast_new_message/broadcast_message_update, on its own DB session, so a slow third-party site never delays message delivery. A separate "link_preview" WS envelope carries the result once it resolves. - SSRF protection reuses app/services/ssrf.py's validate_target_url (renamed from UnsafeWebhookUrlError to UnsafeUrlError now that it's shared with webhooks), but re-validates before every hop of a redirect chain rather than once up front -- redirects are followed manually so each intermediate URL is checked before it's ever connected to. - Parsed with stdlib html.parser -- no new dependency. Frontend: a LinkPreviewCard rendered under message content when present, patched into state live via the new WS envelope and included in message history for reloads. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
53 lines
2.7 KiB
Python
53 lines
2.7 KiB
Python
import uuid
|
|
from datetime import datetime
|
|
|
|
from sqlalchemy import CheckConstraint, DateTime, ForeignKey, String, Text, func
|
|
from sqlalchemy.orm import Mapped, mapped_column, relationship
|
|
|
|
from app.models.base import Base
|
|
|
|
|
|
class Message(Base):
|
|
__tablename__ = "messages"
|
|
__table_args__ = (
|
|
CheckConstraint(
|
|
"content IS NOT NULL OR image_id IS NOT NULL OR file_id IS NOT NULL",
|
|
name="messages_content_or_attachment_required",
|
|
),
|
|
)
|
|
|
|
id: Mapped[uuid.UUID] = mapped_column(primary_key=True, default=uuid.uuid4)
|
|
room_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("rooms.id"), index=True, nullable=False)
|
|
user_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("users.id"), nullable=False)
|
|
# Nullable since Phase "image uploads": a message can be an image with
|
|
# no caption. The CheckConstraint above still requires at least one of
|
|
# content/image_id/file_id.
|
|
content: Mapped[str | None] = mapped_column(Text)
|
|
image_id: Mapped[uuid.UUID | None] = mapped_column(ForeignKey("message_images.id"))
|
|
file_id: Mapped[uuid.UUID | None] = mapped_column(ForeignKey("message_files.id"))
|
|
# First http(s) URL found in content at creation time (see
|
|
# link_preview_service.extract_first_url), if any -- a plain string, not
|
|
# a FK, since the actual preview data lives in link_previews cached by
|
|
# URL and is looked up separately (see message_service.list_recent_
|
|
# messages), not eager-loaded as an ORM relationship.
|
|
preview_url: Mapped[str | None] = mapped_column(String(2048))
|
|
# clock_timestamp(), not now()/func.now() -- the WS handler (ws/chat.py)
|
|
# shares one AsyncSession for a whole connection's lifetime, and a
|
|
# read-only op (e.g. a "join" frame's membership check) can leave a
|
|
# transaction open with nothing to commit it until the next write.
|
|
# Postgres's now()/CURRENT_TIMESTAMP returns the *transaction's* start
|
|
# time in that case, not the actual INSERT's -- confirmed live to be the
|
|
# actual cause of #45 (a reply sent well after an idle read-only period
|
|
# got timestamped to when that period started, sorting it before
|
|
# messages that were genuinely sent earlier). clock_timestamp() always
|
|
# reflects the real moment of execution regardless of transaction age.
|
|
created_at: Mapped[datetime] = mapped_column(
|
|
DateTime(timezone=True), server_default=func.clock_timestamp(), index=True, nullable=False
|
|
)
|
|
edited_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
|
|
deleted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
|
|
|
|
user = relationship("User")
|
|
image = relationship("MessageImage")
|
|
file = relationship("MessageFile")
|