Files
nextcloud-mcp-server/nextcloud_mcp_server/search/semantic.py
T
Chris Coutinho b5b03bfd78 feat: Add multi-document Protocol with cross-app search support
Implements NextcloudClientProtocol for multi-document type search following
user requirement that document types are not 1:1 with apps (e.g., Notes app
specializes in markdown, while Files/WebDAV handles multiple file types).

Key Changes:
- NextcloudClientProtocol: Generic protocol with app-specific client properties
- get_indexed_doc_types(): Query Qdrant for actually-indexed document types
- Document dispatch: All algorithms check Qdrant before attempting access
- Cross-type deduplication: Use (doc_id, doc_type) tuples in hybrid RRF

Search Algorithm Updates:
- Semantic: Added _verify_document_access() with dispatch to appropriate client
  - Deduplication by (doc_id, doc_type) tuple
  - Only "note" verification implemented, others return None with info log
- Keyword: Added _fetch_documents() dispatch method
  - Queries Qdrant for available types before fetching
  - Supports cross-app search when doc_type=None
- Fuzzy: Same pattern as keyword search
- Hybrid: Already uses (doc_id, doc_type) for deduplication (no changes needed)

Future-Proof Design:
- File/calendar verification stubs in place
- Clear logging when unsupported types found
- Easy to extend when processor indexes new document types

Currently Supported:
- "note" documents fully implemented and tested
- Other types gracefully handled (logged but skipped)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-15 01:19:29 +01:00

276 lines
9.6 KiB
Python

"""Semantic search algorithm using vector similarity (Qdrant)."""
import logging
from typing import Any
from httpx import HTTPStatusError
from qdrant_client.models import FieldCondition, Filter, MatchValue
from nextcloud_mcp_server.config import get_settings
from nextcloud_mcp_server.embedding import get_embedding_service
from nextcloud_mcp_server.observability.metrics import record_qdrant_operation
from nextcloud_mcp_server.search.algorithms import (
NextcloudClientProtocol,
SearchAlgorithm,
SearchResult,
)
from nextcloud_mcp_server.vector.qdrant_client import get_qdrant_client
logger = logging.getLogger(__name__)
class SemanticSearchAlgorithm(SearchAlgorithm):
"""Semantic search using vector similarity in Qdrant.
Searches documents by meaning rather than exact keywords using
768-dimensional embeddings and cosine distance.
"""
def __init__(self, score_threshold: float = 0.7):
"""Initialize semantic search algorithm.
Args:
score_threshold: Minimum similarity score (0-1, default: 0.7)
"""
self.score_threshold = score_threshold
@property
def name(self) -> str:
return "semantic"
@property
def requires_vector_db(self) -> bool:
return True
async def search(
self,
query: str,
user_id: str,
limit: int = 10,
doc_type: str | None = None,
nextcloud_client: NextcloudClientProtocol | None = None,
**kwargs: Any,
) -> list[SearchResult]:
"""Execute semantic search using vector similarity.
Args:
query: Natural language search query
user_id: User ID for filtering
limit: Maximum results to return
doc_type: Optional document type filter (currently only "note" supported)
nextcloud_client: NextcloudClient for access verification
**kwargs: Additional parameters (score_threshold override)
Returns:
List of SearchResult objects ranked by similarity score
Raises:
McpError: If vector sync is not enabled or search fails
"""
settings = get_settings()
score_threshold = kwargs.get("score_threshold", self.score_threshold)
logger.info(
f"Semantic search: query='{query}', user={user_id}, "
f"limit={limit}, score_threshold={score_threshold}, doc_type={doc_type}"
)
# Generate embedding for query
embedding_service = get_embedding_service()
query_embedding = await embedding_service.embed(query)
logger.debug(
f"Generated embedding for query (dimension={len(query_embedding)})"
)
# Build Qdrant filter
filter_conditions = [
FieldCondition(
key="user_id",
match=MatchValue(value=user_id),
)
]
# Add doc_type filter if specified
if doc_type:
filter_conditions.append(
FieldCondition(
key="doc_type",
match=MatchValue(value=doc_type),
)
)
# Search Qdrant
qdrant_client = await get_qdrant_client()
try:
search_response = await qdrant_client.query_points(
collection_name=settings.get_collection_name(),
query=query_embedding,
query_filter=Filter(must=filter_conditions),
limit=limit * 2, # Get extra for deduplication
score_threshold=score_threshold,
with_payload=True,
with_vectors=False, # Don't return vectors to save bandwidth
)
record_qdrant_operation("search", "success")
except Exception:
record_qdrant_operation("search", "error")
raise
logger.info(
f"Qdrant returned {len(search_response.points)} results "
f"(before deduplication and access verification)"
)
if search_response.points:
# Log top 3 scores to help with threshold tuning
top_scores = [p.score for p in search_response.points[:3]]
logger.debug(f"Top 3 similarity scores: {top_scores}")
# Deduplicate by document ID (multiple chunks per document)
results = await self._deduplicate_and_verify(
search_response.points, limit, nextcloud_client
)
logger.info(
f"Returning {len(results)} results after deduplication and access verification"
)
if results:
result_details = [
f"{r.doc_type}_{r.id} (score={r.score:.3f}, title='{r.title}')"
for r in results[:5] # Show top 5
]
logger.debug(f"Top results: {', '.join(result_details)}")
return results
async def _deduplicate_and_verify(
self,
points: list[Any],
limit: int,
nextcloud_client: NextcloudClientProtocol | None,
) -> list[SearchResult]:
"""Deduplicate results by (doc_id, doc_type) and verify access.
Supports multiple document types with dispatch to appropriate client methods.
Deduplication is now by (doc_id, doc_type) tuple to handle cases where
the same ID might exist across different document types.
Args:
points: Qdrant search results
limit: Maximum results to return
nextcloud_client: NextcloudClient for access verification (optional)
Returns:
List of SearchResult objects
"""
seen_docs = set() # Track (doc_id, doc_type) tuples
results = []
for result in points:
doc_id = int(result.payload["doc_id"])
doc_type = result.payload.get("doc_type", "note")
doc_key = (doc_id, doc_type)
# Skip if we've already seen this document
if doc_key in seen_docs:
continue
seen_docs.add(doc_key)
# Verify access via Nextcloud API if client provided
# Dispatch to appropriate client based on doc_type
verified_result = None
if nextcloud_client:
verified_result = await self._verify_document_access(
nextcloud_client, doc_id, doc_type, result
)
if verified_result:
results.append(verified_result)
elif not nextcloud_client:
# No access verification, return result directly
results.append(
SearchResult(
id=doc_id,
doc_type=doc_type,
title=result.payload["title"],
excerpt=result.payload["excerpt"],
score=result.score,
metadata={
"chunk_index": result.payload.get("chunk_index"),
"total_chunks": result.payload.get("total_chunks"),
},
)
)
if len(results) >= limit:
break
return results
async def _verify_document_access(
self,
nextcloud_client: NextcloudClientProtocol,
doc_id: int,
doc_type: str,
qdrant_result: Any,
) -> SearchResult | None:
"""Verify user has access to a document via Nextcloud API.
Dispatches to appropriate client method based on document type.
Args:
nextcloud_client: Client for API access
doc_id: Document ID
doc_type: Document type ("note", "file", "calendar", etc.)
qdrant_result: Original Qdrant search result
Returns:
SearchResult if access verified, None if access denied or error
"""
try:
if doc_type == "note":
note = await nextcloud_client.notes.get_note(doc_id)
return SearchResult(
id=doc_id,
doc_type="note",
title=qdrant_result.payload["title"],
excerpt=qdrant_result.payload["excerpt"],
score=qdrant_result.score,
metadata={
"category": note.get("category", ""),
"chunk_index": qdrant_result.payload["chunk_index"],
"total_chunks": qdrant_result.payload["total_chunks"],
},
)
elif doc_type == "file":
# Future: verify file access when files are indexed
logger.info(
f"File {doc_id} found in search but file verification not yet implemented"
)
return None
elif doc_type == "calendar":
# Future: verify calendar access when calendar events are indexed
logger.info(
f"Calendar event {doc_id} found in search but calendar verification not yet implemented"
)
return None
else:
logger.warning(
f"Unknown document type '{doc_type}' for doc_id {doc_id}"
)
return None
except HTTPStatusError as e:
if e.response.status_code in (403, 404):
# User lost access or document deleted
logger.debug(f"Skipping {doc_type} {doc_id}: {e.response.status_code}")
return None
else:
# Log other errors but continue processing
logger.warning(
f"Error verifying access to {doc_type} {doc_id}: {e.response.status_code}"
)
return None