SurfSense/surfsense_backend/app/services/revert_service.py
DESKTOP-RTLN3BA\$punk ca9bbee06d chore: linting
2026-04-28 21:37:51 -07:00

277 lines
8.5 KiB
Python

"""Revert service for the SurfSense agent action log.
Implements the actual revert workflow used by
``POST /api/threads/{thread_id}/revert/{action_id}``. The route handler is a
thin auth + flag wrapper around the functions defined here.
Operation outcomes mirror the plan:
* **KB-owned actions** (NOTE / FILE / FOLDER mutations): restore from
:class:`app.db.DocumentRevision` / :class:`app.db.FolderRevision` rows
written before the original mutation.
* **Connector-owned actions with a declared ``reverse_descriptor``**: invoke
the inverse tool through the agent's normal permission stack (NOT
bypassed). Out of scope for this PR — returns ``REVERSE_NOT_IMPLEMENTED``.
* **Anything else** (deprecated tool / no descriptor / schema drift):
returns ``NOT_REVERSIBLE`` and the route surfaces it as 409.
A successful revert appends a NEW row to ``agent_action_log`` with
``reverse_of=<original_action_id>`` and the requesting user's
``user_id``, preserving an auditable chain.
"""
from __future__ import annotations
import logging
from dataclasses import dataclass
from datetime import UTC, datetime
from typing import Literal
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession
from app.db import (
AgentActionLog,
DocumentRevision,
FolderRevision,
NewChatThread,
)
logger = logging.getLogger(__name__)
RevertOutcomeStatus = Literal[
"ok",
"not_reversible",
"not_found",
"permission_denied",
"tool_unavailable",
"reverse_not_implemented",
]
@dataclass
class RevertOutcome:
"""Structured result of :func:`revert_action`."""
status: RevertOutcomeStatus
message: str
new_action_id: int | None = None
# ---------------------------------------------------------------------------
# Lookup helpers
# ---------------------------------------------------------------------------
async def load_action(
session: AsyncSession,
*,
action_id: int,
thread_id: int,
) -> AgentActionLog | None:
"""Load the action_log row for ``action_id`` if it belongs to the thread."""
stmt = select(AgentActionLog).where(
AgentActionLog.id == action_id,
AgentActionLog.thread_id == thread_id,
)
result = await session.execute(stmt)
return result.scalars().first()
async def load_thread(session: AsyncSession, *, thread_id: int) -> NewChatThread | None:
stmt = select(NewChatThread).where(NewChatThread.id == thread_id)
result = await session.execute(stmt)
return result.scalars().first()
# ---------------------------------------------------------------------------
# Authorization
# ---------------------------------------------------------------------------
def can_revert(
*,
requester_user_id: str | None,
action: AgentActionLog,
is_admin: bool,
) -> bool:
"""Return True iff the requester is allowed to revert this action.
The plan's rule: "requester must be the original `user_id` on the
action, or hold the search-space admin role." Anonymous actions
(``action.user_id is None``) can only be reverted by admins.
"""
if is_admin:
return True
if action.user_id is None:
return False
return str(action.user_id) == str(requester_user_id)
# ---------------------------------------------------------------------------
# Revert paths
# ---------------------------------------------------------------------------
async def _restore_document_revision(
session: AsyncSession, *, action: AgentActionLog
) -> RevertOutcome:
"""Restore the most recent :class:`DocumentRevision` for ``action``."""
stmt = (
select(DocumentRevision)
.where(DocumentRevision.agent_action_id == action.id)
.order_by(DocumentRevision.created_at.desc())
.limit(1)
)
result = await session.execute(stmt)
revision = result.scalars().first()
if revision is None:
return RevertOutcome(
status="not_reversible",
message="No document_revisions row tied to this action.",
)
from app.db import Document # late import to avoid cycles at module load
doc = await session.get(Document, revision.document_id)
if doc is None:
return RevertOutcome(
status="tool_unavailable",
message="Original document has been deleted; revert cannot proceed.",
)
if revision.content_before is not None:
doc.content = revision.content_before
if revision.title_before is not None:
doc.title = revision.title_before
if revision.folder_id_before is not None:
doc.folder_id = revision.folder_id_before
doc.updated_at = datetime.now(UTC)
return RevertOutcome(status="ok", message="Document restored from snapshot.")
async def _restore_folder_revision(
session: AsyncSession, *, action: AgentActionLog
) -> RevertOutcome:
stmt = (
select(FolderRevision)
.where(FolderRevision.agent_action_id == action.id)
.order_by(FolderRevision.created_at.desc())
.limit(1)
)
result = await session.execute(stmt)
revision = result.scalars().first()
if revision is None:
return RevertOutcome(
status="not_reversible",
message="No folder_revisions row tied to this action.",
)
from app.db import Folder
folder = await session.get(Folder, revision.folder_id)
if folder is None:
return RevertOutcome(
status="tool_unavailable",
message="Original folder has been deleted; revert cannot proceed.",
)
if revision.name_before is not None:
folder.name = revision.name_before
if revision.parent_id_before is not None:
folder.parent_id = revision.parent_id_before
if revision.position_before is not None:
folder.position = revision.position_before
folder.updated_at = datetime.now(UTC)
return RevertOutcome(status="ok", message="Folder restored from snapshot.")
# Tool-name prefixes that route to KB document / folder revert paths. Kept
# as data so a future PR adding new KB-owned tools doesn't have to touch
# this module's control flow.
_DOC_TOOL_PREFIXES: tuple[str, ...] = (
"edit_file",
"write_file",
"update_memory",
"create_note",
"update_note",
"delete_note",
)
_FOLDER_TOOL_PREFIXES: tuple[str, ...] = (
"mkdir",
"move_file",
"rename_folder",
"delete_folder",
)
async def revert_action(
session: AsyncSession,
*,
action: AgentActionLog,
requester_user_id: str | None,
) -> RevertOutcome:
"""Execute the revert for ``action`` and return a structured outcome.
The function does **not** commit — the caller is expected to commit on
success or roll back on failure. A new ``agent_action_log`` row is
added to the session on success with ``reverse_of=action.id``.
"""
tool_name = (action.tool_name or "").lower()
if tool_name.startswith(_DOC_TOOL_PREFIXES):
outcome = await _restore_document_revision(session, action=action)
elif tool_name.startswith(_FOLDER_TOOL_PREFIXES):
outcome = await _restore_folder_revision(session, action=action)
elif action.reverse_descriptor:
# Connector-owned reversibles run through the normal permission
# stack; out of scope for this PR — the route returns 503 anyway
# until UI ships, so 501-style "not implemented" is fine.
return RevertOutcome(
status="reverse_not_implemented",
message=(
"Connector-action revert is not yet implemented. The "
"reverse_descriptor is stored; future work will replay it "
"through PermissionMiddleware."
),
)
else:
return RevertOutcome(
status="not_reversible",
message=(
f"Tool {action.tool_name!r} is not reversible: no document "
"revision and no reverse_descriptor."
),
)
if outcome.status != "ok":
return outcome
new_row = AgentActionLog(
thread_id=action.thread_id,
user_id=requester_user_id,
search_space_id=action.search_space_id,
turn_id=None,
message_id=None,
tool_name=f"_revert:{action.tool_name}",
args={"reverted_action_id": action.id},
result_id=None,
reversible=False,
reverse_descriptor=None,
error=None,
reverse_of=action.id,
)
session.add(new_row)
await session.flush()
outcome.new_action_id = new_row.id
return outcome
__all__ = [
"RevertOutcome",
"can_revert",
"load_action",
"load_thread",
"revert_action",
]