SurfSense/surfsense_backend/app/agents/new_chat/path_resolver.py
2026-04-28 04:32:52 -07:00

351 lines
12 KiB
Python

"""Canonical virtual-path resolver for SurfSense knowledge-base documents.
This module is the single source of truth for mapping ``Document`` rows to
virtual paths under ``/documents/`` and back. It is used by:
* :class:`KnowledgeTreeMiddleware` (rendering the workspace tree)
* :class:`KnowledgePriorityMiddleware` (computing priority paths)
* :class:`KBPostgresBackend` (``als_info`` / ``aread`` / move operations)
* :class:`KnowledgeBasePersistenceMiddleware` (resolving moves and creates)
Centralising the logic ensures that title-collision suffixes, folder paths,
and ``unique_identifier_hash`` lookups never drift between renders and
commits.
"""
from __future__ import annotations
import re
from dataclasses import dataclass, field
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession
from app.db import Document, DocumentType, Folder
from app.utils.document_converters import generate_unique_identifier_hash
DOCUMENTS_ROOT = "/documents"
"""Root virtual folder for all KB documents."""
_INVALID_FILENAME_CHARS = re.compile(r"[\\/:*?\"<>|]+")
_WHITESPACE_RUN = re.compile(r"\s+")
def safe_filename(value: str, *, fallback: str = "untitled.xml") -> str:
"""Convert arbitrary text into a filesystem-safe ``.xml`` filename."""
name = _INVALID_FILENAME_CHARS.sub("_", value).strip()
name = _WHITESPACE_RUN.sub(" ", name)
if not name:
name = fallback
if len(name) > 180:
name = name[:180].rstrip()
if not name.lower().endswith(".xml"):
name = f"{name}.xml"
return name
def safe_folder_segment(value: str, *, fallback: str = "folder") -> str:
"""Sanitize a single folder name into a path-safe segment."""
name = _INVALID_FILENAME_CHARS.sub("_", value).strip()
name = _WHITESPACE_RUN.sub(" ", name)
if not name:
return fallback
if len(name) > 180:
name = name[:180].rstrip()
return name
def _suffix_with_doc_id(filename: str, doc_id: int | None) -> str:
if doc_id is None:
return filename
if not filename.lower().endswith(".xml"):
return f"{filename} ({doc_id}).xml"
stem = filename[:-4]
return f"{stem} ({doc_id}).xml"
_SUFFIX_PATTERN = re.compile(r"\s\((\d+)\)\.xml$", re.IGNORECASE)
def parse_doc_id_suffix(filename: str) -> tuple[str, int | None]:
"""Strip a trailing ``" (<doc_id>).xml"`` suffix; return ``(stem, doc_id)``.
If no suffix is present, returns ``(stem_without_xml_extension, None)``.
"""
match = _SUFFIX_PATTERN.search(filename)
if match:
doc_id = int(match.group(1))
stem = filename[: match.start()]
return stem, doc_id
if filename.lower().endswith(".xml"):
return filename[:-4], None
return filename, None
@dataclass
class PathIndex:
"""In-memory occupancy snapshot used by :func:`doc_to_virtual_path`.
Built once per call site so collision handling is deterministic and so
we don't perform N folder lookups per render.
"""
folder_paths: dict[int, str] = field(default_factory=dict)
"""``Folder.id`` -> absolute virtual folder path under ``/documents``."""
occupants: dict[str, int] = field(default_factory=dict)
"""virtual path -> ``Document.id`` already occupying that path (this render)."""
async def _build_folder_paths(
session: AsyncSession,
search_space_id: int,
) -> dict[int, str]:
"""Compute ``Folder.id`` -> absolute virtual path under ``/documents``."""
result = await session.execute(
select(Folder.id, Folder.name, Folder.parent_id).where(
Folder.search_space_id == search_space_id
)
)
rows = result.all()
by_id = {row.id: {"name": row.name, "parent_id": row.parent_id} for row in rows}
cache: dict[int, str] = {}
def resolve(folder_id: int) -> str:
if folder_id in cache:
return cache[folder_id]
parts: list[str] = []
cursor: int | None = folder_id
visited: set[int] = set()
while cursor is not None and cursor in by_id and cursor not in visited:
visited.add(cursor)
entry = by_id[cursor]
parts.append(safe_folder_segment(str(entry["name"])))
cursor = entry["parent_id"]
parts.reverse()
path = f"{DOCUMENTS_ROOT}/" + "/".join(parts) if parts else DOCUMENTS_ROOT
cache[folder_id] = path
return path
for folder_id in by_id:
resolve(folder_id)
return cache
async def build_path_index(
session: AsyncSession,
search_space_id: int,
*,
populate_occupants: bool = True,
) -> PathIndex:
"""Build a :class:`PathIndex` for a search space.
``populate_occupants`` controls whether the occupancy map is pre-seeded
from existing ``Document`` rows. Most callers want this so that
:func:`doc_to_virtual_path` can detect collisions across the whole space;
the persistence middleware sets this to ``False`` when it is iterating to
decide where to place fresh documents.
"""
folder_paths = await _build_folder_paths(session, search_space_id)
occupants: dict[str, int] = {}
if populate_occupants:
rows = await session.execute(
select(Document.id, Document.title, Document.folder_id).where(
Document.search_space_id == search_space_id,
)
)
for row in rows.all():
base = folder_paths.get(row.folder_id, DOCUMENTS_ROOT)
filename = safe_filename(str(row.title or "untitled"))
path = f"{base}/{filename}"
if path in occupants and occupants[path] != row.id:
path = f"{base}/{_suffix_with_doc_id(filename, row.id)}"
occupants[path] = row.id
return PathIndex(folder_paths=folder_paths, occupants=occupants)
def doc_to_virtual_path(
*,
doc_id: int | None,
title: str,
folder_id: int | None,
index: PathIndex,
) -> str:
"""Return the canonical virtual path for a document.
Mutates ``index.occupants`` so subsequent calls see this assignment and
deterministically pick a different suffix for the next colliding doc.
"""
base = index.folder_paths.get(folder_id, DOCUMENTS_ROOT)
filename = safe_filename(str(title or "untitled"))
path = f"{base}/{filename}"
occupant = index.occupants.get(path)
if occupant is not None and occupant != doc_id:
path = f"{base}/{_suffix_with_doc_id(filename, doc_id)}"
if doc_id is not None:
index.occupants[path] = doc_id
return path
async def virtual_path_to_doc(
session: AsyncSession,
*,
search_space_id: int,
virtual_path: str,
) -> Document | None:
"""Resolve a virtual path back to a ``Document`` row.
Resolution order:
1. ``Document.unique_identifier_hash`` lookup (fast path for paths created
by SurfSense itself — every NOTE write goes through this hash).
2. If the basename carries a ``" (<doc_id>).xml"`` disambiguation suffix,
try a direct id lookup constrained to the search space.
3. Title-from-basename + folder-resolution lookup as a last resort.
"""
if not virtual_path or not virtual_path.startswith(DOCUMENTS_ROOT):
return None
unique_hash = generate_unique_identifier_hash(
DocumentType.NOTE,
virtual_path,
search_space_id,
)
result = await session.execute(
select(Document).where(
Document.search_space_id == search_space_id,
Document.unique_identifier_hash == unique_hash,
)
)
document = result.scalar_one_or_none()
if document is not None:
return document
rel = virtual_path[len(DOCUMENTS_ROOT) :].lstrip("/")
if not rel:
return None
parts = [p for p in rel.split("/") if p]
if not parts:
return None
basename = parts[-1]
folder_parts = parts[:-1]
stem, suffix_doc_id = parse_doc_id_suffix(basename)
if suffix_doc_id is not None:
result = await session.execute(
select(Document).where(
Document.search_space_id == search_space_id,
Document.id == suffix_doc_id,
)
)
document = result.scalar_one_or_none()
if document is not None:
return document
folder_id = await _resolve_folder_id(
session, search_space_id=search_space_id, folder_parts=folder_parts
)
title_candidates: list[str] = []
raw_title = stem
title_candidates.append(raw_title)
if raw_title.endswith(".xml"):
title_candidates.append(raw_title[:-4])
for candidate in dict.fromkeys(title_candidates):
if not candidate:
continue
query = select(Document).where(
Document.search_space_id == search_space_id,
Document.title == candidate,
)
if folder_id is None:
query = query.where(Document.folder_id.is_(None))
else:
query = query.where(Document.folder_id == folder_id)
result = await session.execute(query)
document = result.scalars().first()
if document is not None:
return document
# Fallback: title-as-string lookup misses when the real DB title contains
# characters that ``safe_filename`` lossily replaces (``:``, ``/``, ``*``,
# etc.) — common for connector-imported docs (Google Calendar/Drive etc.).
# The workspace tree shows the lossy filename, so the agent passes that
# filename back here. Scan all documents in the resolved folder and match
# by ``safe_filename(title)`` to recover the original document.
folder_scan = select(Document).where(
Document.search_space_id == search_space_id,
)
if folder_id is None:
folder_scan = folder_scan.where(Document.folder_id.is_(None))
else:
folder_scan = folder_scan.where(Document.folder_id == folder_id)
result = await session.execute(folder_scan)
for candidate_doc in result.scalars().all():
encoded = safe_filename(str(candidate_doc.title or "untitled"))
if encoded == basename:
return candidate_doc
return None
async def _resolve_folder_id(
session: AsyncSession,
*,
search_space_id: int,
folder_parts: list[str],
) -> int | None:
"""Look up the leaf folder id for a chain of folder names; return ``None`` if missing."""
if not folder_parts:
return None
parent_id: int | None = None
for raw in folder_parts:
name = safe_folder_segment(raw)
query = select(Folder.id).where(
Folder.search_space_id == search_space_id,
Folder.name == name,
)
if parent_id is None:
query = query.where(Folder.parent_id.is_(None))
else:
query = query.where(Folder.parent_id == parent_id)
result = await session.execute(query)
row = result.first()
if row is None:
return None
parent_id = row[0]
return parent_id
def parse_documents_path(virtual_path: str) -> tuple[list[str], str]:
"""Parse a ``/documents/...`` path into ``(folder_parts, document_title)``.
The title has any ``.xml`` extension and trailing ``" (<doc_id>)"``
disambiguation suffix stripped.
"""
if not virtual_path or not virtual_path.startswith(DOCUMENTS_ROOT):
return [], ""
rel = virtual_path[len(DOCUMENTS_ROOT) :].strip("/")
if not rel:
return [], ""
parts = [p for p in rel.split("/") if p]
if not parts:
return [], ""
folder_parts = parts[:-1]
basename = parts[-1]
stem, _ = parse_doc_id_suffix(basename)
title = stem
if title.endswith(".xml"):
title = title[:-4]
return folder_parts, title
__all__ = [
"DOCUMENTS_ROOT",
"PathIndex",
"build_path_index",
"doc_to_virtual_path",
"parse_doc_id_suffix",
"parse_documents_path",
"safe_filename",
"safe_folder_segment",
"virtual_path_to_doc",
]