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nextcloud-mcp-server/nextcloud_mcp_server/search/keyword.py
T
Chris Coutinho 2a078093ed refactor!: Make all search algorithms query Qdrant payload, not Nextcloud
BREAKING CHANGE: Search algorithms now require Qdrant to be populated.
Vector sync must be enabled and documents indexed for search to work.

- Keyword and fuzzy search now query Qdrant scroll API for title/excerpt
- Remove inefficient Nextcloud API fetching pattern
- Add optional Nextcloud verification for security
- Deduplicate by (doc_id, doc_type) tuple, keeping chunk_index=0
- Align with document processor pattern that already stores text in Qdrant
2025-11-15 01:56:41 +01:00

345 lines
12 KiB
Python

"""Keyword search algorithm using token-based matching on Qdrant payload (ADR-001)."""
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.search.algorithms import (
NextcloudClientProtocol,
SearchAlgorithm,
SearchResult,
)
from nextcloud_mcp_server.vector.qdrant_client import get_qdrant_client
logger = logging.getLogger(__name__)
class KeywordSearchAlgorithm(SearchAlgorithm):
"""Keyword search using token-based matching with weighted scoring.
Implements token-based search from ADR-001:
- Title matches weighted 3x higher than content matches
- Case-insensitive token matching
- Relevance scoring based on match frequency and location
"""
# Weighting constants from ADR-001
TITLE_WEIGHT = 3.0
CONTENT_WEIGHT = 1.0
@property
def name(self) -> str:
return "keyword"
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 keyword search using token matching on Qdrant payload.
Queries Qdrant for all indexed documents, then scores based on token
matches in title and excerpt fields. Only verifies access with Nextcloud
at the end for security.
Args:
query: Search query to tokenize and match
user_id: User ID for filtering
limit: Maximum results to return
doc_type: Optional document type filter (None = all types)
nextcloud_client: NextcloudClient for access verification (optional)
**kwargs: Additional parameters (unused)
Returns:
List of SearchResult objects ranked by keyword match score
"""
settings = get_settings()
logger.info(
f"Keyword search: query='{query}', user={user_id}, "
f"limit={limit}, doc_type={doc_type}"
)
# Tokenize query
query_tokens = self._process_query(query)
logger.debug(f"Query tokens: {query_tokens}")
# Build Qdrant filter
filter_conditions = [
FieldCondition(key="user_id", match=MatchValue(value=user_id))
]
if doc_type:
filter_conditions.append(
FieldCondition(key="doc_type", match=MatchValue(value=doc_type))
)
# Scroll through Qdrant to get all matching documents
# We need title and excerpt from payload for token matching
qdrant_client = await get_qdrant_client()
collection = settings.qdrant_collection
all_points = []
offset = None
# Scroll through all points matching filter
while True:
scroll_result, next_offset = await qdrant_client.scroll(
collection_name=collection,
scroll_filter=Filter(must=filter_conditions),
limit=100, # Batch size
offset=offset,
with_payload=[
"doc_id",
"doc_type",
"title",
"excerpt",
"chunk_index",
"total_chunks",
],
with_vectors=False, # Don't need vectors for keyword search
)
all_points.extend(scroll_result)
if next_offset is None:
break
offset = next_offset
logger.debug(
f"Retrieved {len(all_points)} points from Qdrant for keyword search"
)
# Deduplicate by (doc_id, doc_type) - keep best chunk per document
seen_docs = {}
for point in all_points:
doc_id = int(point.payload["doc_id"])
dtype = point.payload.get("doc_type", "note")
doc_key = (doc_id, dtype)
# Keep first chunk (chunk_index=0) as it has the most relevant content
chunk_idx = point.payload.get("chunk_index", 0)
if doc_key not in seen_docs or chunk_idx == 0:
seen_docs[doc_key] = point
logger.debug(f"Deduplicated to {len(seen_docs)} unique documents")
# Score each document based on keyword matches
scored_results = []
for doc_key, point in seen_docs.items():
doc_id, dtype = doc_key
title = point.payload.get("title", "")
excerpt = point.payload.get("excerpt", "")
# Calculate keyword match score
score = self._calculate_score(query_tokens, title, excerpt)
if score > 0: # Only include matches
scored_results.append(
{
"doc_id": doc_id,
"doc_type": dtype,
"title": title,
"excerpt": excerpt,
"score": score,
}
)
# Sort by score (descending) and limit
scored_results.sort(key=lambda x: x["score"], reverse=True)
top_results = scored_results[: limit * 2] # Get extra for access verification
# Verify access with Nextcloud (optional, for security)
final_results = []
if nextcloud_client:
for result in top_results:
verified = await self._verify_access(
nextcloud_client, result["doc_id"], result["doc_type"]
)
if verified:
final_results.append(
SearchResult(
id=result["doc_id"],
doc_type=result["doc_type"],
title=result["title"],
excerpt=result["excerpt"],
score=result["score"],
metadata=verified.get("metadata", {}),
)
)
if len(final_results) >= limit:
break
else:
# No verification, return results directly
for result in top_results[:limit]:
final_results.append(
SearchResult(
id=result["doc_id"],
doc_type=result["doc_type"],
title=result["title"],
excerpt=result["excerpt"],
score=result["score"],
metadata={},
)
)
logger.info(f"Keyword search returned {len(final_results)} matching documents")
if final_results:
result_details = [
f"{r.doc_type}_{r.id} (score={r.score:.3f}, title='{r.title}')"
for r in final_results[:5]
]
logger.debug(f"Top keyword results: {', '.join(result_details)}")
return final_results
async def _verify_access(
self, nextcloud_client: NextcloudClientProtocol, doc_id: int, doc_type: str
) -> dict[str, Any] | None:
"""Verify user has access to a document via Nextcloud API.
Args:
nextcloud_client: Client for API access
doc_id: Document ID
doc_type: Document type
Returns:
Dict with metadata if access verified, None otherwise
"""
try:
if doc_type == "note":
note = await nextcloud_client.notes.get_note(doc_id)
return {
"metadata": {
"category": note.get("category", ""),
"modified": note.get("modified"),
}
}
# Future: Add verification for other document types
else:
logger.debug(
f"Skipping verification for {doc_type} {doc_id} (not implemented)"
)
return {"metadata": {}}
except HTTPStatusError as e:
if e.response.status_code in (403, 404):
logger.debug(
f"Access denied for {doc_type} {doc_id}: {e.response.status_code}"
)
return None
else:
logger.warning(
f"Error verifying {doc_type} {doc_id}: {e.response.status_code}"
)
return None
def _process_query(self, query: str) -> list[str]:
"""Tokenize and normalize query.
Args:
query: Raw query string
Returns:
List of normalized tokens
"""
# Convert to lowercase and split into tokens
tokens = query.lower().split()
# Filter out very short tokens (optional)
tokens = [token for token in tokens if len(token) > 1]
return tokens
def _calculate_score(
self, query_tokens: list[str], title: str, content: str
) -> float:
"""Calculate relevance score based on token matches.
Args:
query_tokens: List of query tokens
title: Document title
content: Document content
Returns:
Relevance score (0.0-1.0)
"""
if not query_tokens:
return 0.0
# Process title and content
title_tokens = title.lower().split()
content_tokens = content.lower().split()
score = 0.0
# Count matches in title
title_matches = sum(1 for qt in query_tokens if qt in title_tokens)
if query_tokens: # Avoid division by zero
title_match_ratio = title_matches / len(query_tokens)
score += self.TITLE_WEIGHT * title_match_ratio
# Count matches in content
content_matches = sum(1 for qt in query_tokens if qt in content_tokens)
if query_tokens:
content_match_ratio = content_matches / len(query_tokens)
score += self.CONTENT_WEIGHT * content_match_ratio
# Normalize score to 0-1 range
# Max score would be TITLE_WEIGHT + CONTENT_WEIGHT if all tokens match everywhere
max_score = self.TITLE_WEIGHT + self.CONTENT_WEIGHT
normalized_score = min(score / max_score, 1.0)
return normalized_score
def _extract_excerpt(
self, content: str, query_tokens: list[str], max_length: int = 200
) -> str:
"""Extract excerpt showing match context.
Args:
content: Full document content
query_tokens: Query tokens to find
max_length: Maximum excerpt length in characters
Returns:
Excerpt string with context around matches
"""
if not content:
return ""
content_lower = content.lower()
# Find first occurrence of any query token
first_match_pos = -1
for token in query_tokens:
pos = content_lower.find(token)
if pos != -1:
if first_match_pos == -1 or pos < first_match_pos:
first_match_pos = pos
if first_match_pos == -1:
# No matches found, return beginning
return content[:max_length].strip() + (
"..." if len(content) > max_length else ""
)
# Extract context around match
start = max(0, first_match_pos - max_length // 2)
end = min(len(content), first_match_pos + max_length // 2)
excerpt = content[start:end].strip()
# Add ellipsis if truncated
if start > 0:
excerpt = "..." + excerpt
if end < len(content):
excerpt = excerpt + "..."
return excerpt