Files
nextcloud-mcp-server/nextcloud_mcp_server/auth/viz_routes.py
T
Chris Coutinho fffe483c02 fix: Centralize PDF processing and generate separate images per chunk
Previously, pymupdf4llm.to_markdown() was called twice - once in
PyMuPDFProcessor during indexing and again in PDFHighlighter during
visualization. Different image path lengths caused different character
offsets, leading to highlighted pages not matching their chunks.

Also fixed issue where all chunks on the same page showed all highlights
instead of just their own highlight. Now restores original page contents
between chunks using xref stream caching.

Changes:
- Add PDFHighlighter class requiring pre-computed page_boundaries and
  full_text from document processor (no fallback extraction)
- Pass pre-computed data from processor to highlighter
- Extract page-relative portion of chunk text for cross-page chunks
- Add bounding box highlighting using text anchor search
- Run highlight generation in parallel with embedding/BM25
- Cache and restore page contents to isolate highlights per chunk

Results: Highlighting success rate improved from 51% to 95% (121/128).

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

Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-22 02:46:30 +01:00

646 lines
26 KiB
Python

"""Vector visualization routes for testing search algorithms.
Provides a web UI for users to test different search algorithms on their own
indexed documents and visualize results in 3D space using PCA.
All processing happens server-side following ADR-012:
- Search execution via shared search/algorithms.py
- Query embedding generation
- PCA dimensionality reduction (768-dim → 3D)
- Only 3D coordinates + metadata sent to client
- Bandwidth-efficient (3 floats per doc vs 768)
"""
import logging
import time
from pathlib import Path
import numpy as np
from jinja2 import Environment, FileSystemLoader
from starlette.authentication import requires
from starlette.requests import Request
from starlette.responses import HTMLResponse, JSONResponse
from nextcloud_mcp_server.config import get_settings
from nextcloud_mcp_server.search import (
BM25HybridSearchAlgorithm,
SemanticSearchAlgorithm,
)
from nextcloud_mcp_server.vector.pca import PCA
from nextcloud_mcp_server.vector.placeholder import get_placeholder_filter
from nextcloud_mcp_server.vector.qdrant_client import get_qdrant_client
logger = logging.getLogger(__name__)
# Setup Jinja2 environment for templates
_template_dir = Path(__file__).parent / "templates"
_jinja_env = Environment(loader=FileSystemLoader(_template_dir))
@requires("authenticated", redirect="oauth_login")
async def vector_visualization_html(request: Request) -> HTMLResponse:
"""Vector visualization page with search controls and interactive plot.
Provides UI for testing search algorithms with real-time visualization.
Requires vector sync to be enabled.
Args:
request: Starlette request object
Returns:
HTML page with search interface
"""
settings = get_settings()
if not settings.vector_sync_enabled:
return HTMLResponse(
"""
<div>
<h2>Vector Visualization</h2>
<div style="padding: 20px; background: #fff3cd; border: 1px solid #ffc107; border-radius: 4px;">
Vector sync is not enabled. Set VECTOR_SYNC_ENABLED=true to use this feature.
</div>
</div>
"""
)
# Get user info from auth context
username = (
request.user.display_name
if hasattr(request.user, "display_name")
else "unknown"
)
# Load and render template
template = _jinja_env.get_template("vector_viz.html")
html_content = template.render(username=username)
return HTMLResponse(content=html_content)
@requires("authenticated", redirect="oauth_login")
async def vector_visualization_search(request: Request) -> JSONResponse:
"""Execute server-side search and return 3D coordinates + results.
All processing happens server-side:
1. Execute search via shared algorithm module
2. Generate query embedding
3. Fetch matching vectors from Qdrant
4. Apply PCA reduction (768-dim → 3D) to query + documents
5. Return coordinates + metadata only
Args:
request: Starlette request with query parameters
Returns:
JSON response with coordinates_3d and results (including query point)
"""
settings = get_settings()
if not settings.vector_sync_enabled:
return JSONResponse(
{"success": False, "error": "Vector sync not enabled"},
status_code=400,
)
# Get user info from auth context
username = (
request.user.display_name if hasattr(request.user, "display_name") else None
)
if not username:
return JSONResponse(
{"success": False, "error": "User not authenticated"},
status_code=401,
)
# Parse query parameters
query = request.query_params.get("query", "")
algorithm = request.query_params.get("algorithm", "bm25_hybrid")
limit = int(request.query_params.get("limit", "50"))
score_threshold = float(request.query_params.get("score_threshold", "0.0"))
fusion = request.query_params.get("fusion", "rrf") # Default to RRF
# Parse doc_types (comma-separated list, None = all types)
doc_types_param = request.query_params.get("doc_types", "")
doc_types = doc_types_param.split(",") if doc_types_param else None
logger.info(
f"Viz search: user={username}, query='{query}', "
f"algorithm={algorithm}, fusion={fusion}, limit={limit}, doc_types={doc_types}"
)
try:
# Start total request timer
request_start = time.perf_counter()
# Get authenticated HTTP client from session
# In BasicAuth mode: uses username/password from session
# In OAuth mode: uses access token from session
from nextcloud_mcp_server.auth.userinfo_routes import (
_get_authenticated_client_for_userinfo,
)
async with await _get_authenticated_client_for_userinfo(request) as nc_client: # noqa: F841
# Create search algorithm (no client needed - verification removed)
if algorithm == "semantic":
search_algo = SemanticSearchAlgorithm(score_threshold=score_threshold)
elif algorithm == "bm25_hybrid":
search_algo = BM25HybridSearchAlgorithm(
score_threshold=score_threshold, fusion=fusion
)
else:
return JSONResponse(
{"success": False, "error": f"Unknown algorithm: {algorithm}"},
status_code=400,
)
# Execute search (supports cross-app when doc_types=None)
# Get unverified results with buffer for filtering
search_start = time.perf_counter()
all_results = []
if doc_types is None or len(doc_types) == 0:
# Cross-app search - search all indexed types
unverified_results = await search_algo.search(
query=query,
user_id=username,
limit=limit * 2, # Buffer for verification filtering
doc_type=None, # Search all types
score_threshold=score_threshold,
)
all_results.extend(unverified_results)
else:
# Search each document type and combine
for doc_type in doc_types:
unverified_results = await search_algo.search(
query=query,
user_id=username,
limit=limit * 2, # Buffer for verification filtering
doc_type=doc_type,
score_threshold=score_threshold,
)
all_results.extend(unverified_results)
# Sort by score before verification
all_results.sort(key=lambda r: r.score, reverse=True)
# No verification needed for visualization - we only need Qdrant metadata
# (title, excerpt, doc_type) which is already in search results.
# Verification is only needed for sampling (LLM needs full content).
search_results = all_results[:limit]
search_duration = time.perf_counter() - search_start
# Store original scores and normalize for visualization
# (best result = 1.0, worst result = 0.0 within THIS result set)
# This makes visual encoding meaningful regardless of RRF normalization
if search_results:
scores = [r.score for r in search_results]
min_score, max_score = min(scores), max(scores)
score_range = max_score - min_score if max_score > min_score else 1.0
logger.info(
f"Normalizing scores for viz: original range [{min_score:.3f}, {max_score:.3f}] "
f"→ [0.0, 1.0]"
)
# Store original score and rescale to 0-1 for visualization
for r in search_results:
# Store original score before normalization
r.original_score = r.score
# Rescale for visual encoding
r.score = (r.score - min_score) / score_range
if not search_results:
return JSONResponse(
{
"success": True,
"results": [],
"coordinates_3d": [],
"query_coords": [],
"message": "No results found",
}
)
# Fetch vectors for specific matching chunks from Qdrant
vector_fetch_start = time.perf_counter()
qdrant_client = await get_qdrant_client()
# Build filters for each specific chunk
from qdrant_client.models import FieldCondition, Filter, MatchValue
chunk_vectors_map = {} # Map (doc_id, chunk_start, chunk_end) -> vector
# Fetch vectors in batches by filtering on chunk-specific fields
for result in search_results:
chunk_start = result.chunk_start_offset
chunk_end = result.chunk_end_offset
# Build filter for this specific chunk
must_conditions = [
get_placeholder_filter(), # Always exclude placeholders from user-facing queries
FieldCondition(
key="doc_id",
match=MatchValue(value=result.id),
),
FieldCondition(
key="user_id",
match=MatchValue(value=username),
),
]
# Add chunk position filters if available
if chunk_start is not None:
must_conditions.append(
FieldCondition(
key="chunk_start_offset",
match=MatchValue(value=chunk_start),
)
)
if chunk_end is not None:
must_conditions.append(
FieldCondition(
key="chunk_end_offset",
match=MatchValue(value=chunk_end),
)
)
# Fetch this specific chunk vector
points_response = await qdrant_client.scroll(
collection_name=settings.get_collection_name(),
scroll_filter=Filter(must=must_conditions),
limit=1, # Only need the first match
with_vectors=["dense"],
with_payload=False,
)
points = points_response[0]
if points:
# Extract dense vector
point = points[0]
if point.vector is not None:
# If named vectors (dict), extract "dense"
if isinstance(point.vector, dict):
vector = point.vector.get("dense")
else:
vector = point.vector
chunk_key = (result.id, chunk_start, chunk_end)
chunk_vectors_map[chunk_key] = vector
vector_fetch_duration = time.perf_counter() - vector_fetch_start
if len(chunk_vectors_map) < 2:
# Not enough chunks for PCA
return JSONResponse(
{
"success": True,
"results": [
{
"id": r.id,
"doc_type": r.doc_type,
"title": r.title,
"excerpt": r.excerpt,
"score": r.score,
}
for r in search_results
],
"coordinates_3d": [[0, 0, 0]] * len(search_results),
"query_coords": [0, 0, 0],
"message": "Not enough chunks for PCA",
}
)
# Detect embedding dimension from first available vector
embedding_dim = None
for vector in chunk_vectors_map.values():
if vector is not None:
embedding_dim = len(vector)
break
if embedding_dim is None:
return JSONResponse(
{
"success": False,
"error": "Could not determine embedding dimension",
},
status_code=500,
)
logger.info(f"Detected embedding dimension: {embedding_dim}")
# Build chunk vectors array in search_results order (1:1 mapping)
chunk_vectors = []
for result in search_results:
chunk_key = (result.id, result.chunk_start_offset, result.chunk_end_offset)
if chunk_key in chunk_vectors_map:
chunk_vectors.append(chunk_vectors_map[chunk_key])
else:
# Chunk not found in vectors (shouldn't happen)
logger.warning(
f"Chunk {chunk_key} not found in fetched vectors, using zero vector"
)
# Use zero vector as fallback
chunk_vectors.append(np.zeros(embedding_dim))
chunk_vectors = np.array(chunk_vectors)
# Generate query embedding for visualization
query_embed_start = time.perf_counter()
from nextcloud_mcp_server.embedding.service import get_embedding_service
embedding_service = get_embedding_service()
query_embedding = await embedding_service.embed(query)
query_embed_duration = time.perf_counter() - query_embed_start
logger.info(f"Generated query embedding (dimension={len(query_embedding)})")
# Combine query vector with chunk vectors for PCA
# Query will be the last point in the array
all_vectors = np.vstack([chunk_vectors, np.array([query_embedding])])
# Normalize vectors to unit length (L2 normalization)
# This is critical because Qdrant uses COSINE distance, which only measures
# vector direction (angle), not magnitude. PCA uses Euclidean distance which
# considers both direction and magnitude. By normalizing to unit length,
# Euclidean distances in PCA space will match cosine distances.
norms = np.linalg.norm(all_vectors, axis=1, keepdims=True)
# Check for zero-norm vectors (can happen with empty/corrupted embeddings)
zero_norm_mask = norms[:, 0] < 1e-10
if zero_norm_mask.any():
zero_indices = np.where(zero_norm_mask)[0]
logger.warning(
f"Found {zero_norm_mask.sum()} zero-norm vectors at indices {zero_indices.tolist()}. "
"Replacing with small epsilon to avoid division by zero."
)
# Replace zero norms with small epsilon to avoid NaN
norms[zero_norm_mask] = 1e-10
all_vectors_normalized = all_vectors / norms
logger.info(
f"Normalized vectors: query_norm={norms[-1][0]:.3f}, "
f"doc_norm_range=[{norms[:-1].min():.3f}, {norms[:-1].max():.3f}]"
)
# Apply PCA dimensionality reduction (768-dim → 3D) on normalized vectors
pca_start = time.perf_counter()
pca = PCA(n_components=3)
coords_3d = pca.fit_transform(all_vectors_normalized)
pca_duration = time.perf_counter() - pca_start
# After fit, these attributes are guaranteed to be set
assert pca.explained_variance_ratio_ is not None
# Check for NaN values in PCA output (numerical instability)
nan_mask = np.isnan(coords_3d)
if nan_mask.any():
nan_rows = np.where(nan_mask.any(axis=1))[0]
logger.error(
f"Found NaN values in PCA output at {len(nan_rows)} points: {nan_rows.tolist()[:10]}. "
"Replacing NaN with 0.0 to prevent JSON serialization error."
)
# Replace NaN with 0 to allow JSON serialization
coords_3d = np.nan_to_num(coords_3d, nan=0.0)
# Split query coords from chunk coords
# Round to 2 decimal places for cleaner display
query_coords_3d = [
round(float(x), 2) for x in coords_3d[-1]
] # Last point is query
chunk_coords_3d = coords_3d[:-1] # All but last are chunks
logger.info(
f"PCA explained variance: PC1={pca.explained_variance_ratio_[0]:.3f}, "
f"PC2={pca.explained_variance_ratio_[1]:.3f}, "
f"PC3={pca.explained_variance_ratio_[2]:.3f}"
)
logger.info(
f"Embedding stats: chunks={len(chunk_vectors)}, "
f"query_dim={len(query_embedding)}, chunk_vector_dim={chunk_vectors.shape[1] if chunk_vectors.size > 0 else 0}"
)
# Coordinates already match search_results order (1:1 mapping)
result_coords = [
[round(float(x), 2) for x in coord] for coord in chunk_coords_3d
]
# Build response
response_results = [
{
"id": r.id,
"doc_type": r.doc_type,
"title": r.title,
"excerpt": r.excerpt,
"score": r.score, # Normalized score for visual encoding (0-1)
"original_score": getattr(
r, "original_score", r.score
), # Raw score from algorithm
"chunk_start_offset": r.chunk_start_offset,
"chunk_end_offset": r.chunk_end_offset,
}
for r in search_results
]
# Calculate total request duration
total_duration = time.perf_counter() - request_start
# Log comprehensive timing metrics
logger.info(
f"Viz search timing: total={total_duration * 1000:.1f}ms, "
f"search={search_duration * 1000:.1f}ms ({search_duration / total_duration * 100:.1f}%), "
f"vector_fetch={vector_fetch_duration * 1000:.1f}ms ({vector_fetch_duration / total_duration * 100:.1f}%), "
f"query_embed={query_embed_duration * 1000:.1f}ms ({query_embed_duration / total_duration * 100:.1f}%), "
f"pca={pca_duration * 1000:.1f}ms ({pca_duration / total_duration * 100:.1f}%), "
f"results={len(search_results)}, chunk_vectors={len(chunk_vectors)}"
)
return JSONResponse(
{
"success": True,
"results": response_results,
"coordinates_3d": result_coords[: len(search_results)],
"query_coords": query_coords_3d,
"pca_variance": {
"pc1": float(pca.explained_variance_ratio_[0]),
"pc2": float(pca.explained_variance_ratio_[1]),
"pc3": float(pca.explained_variance_ratio_[2]),
},
"timing": {
"total_ms": round(total_duration * 1000, 2),
"search_ms": round(search_duration * 1000, 2),
"vector_fetch_ms": round(vector_fetch_duration * 1000, 2),
"query_embed_ms": round(query_embed_duration * 1000, 2),
"pca_ms": round(pca_duration * 1000, 2),
"num_results": len(search_results),
"num_chunk_vectors": len(chunk_vectors),
},
}
)
except Exception as e:
logger.error(f"Viz search error: {e}", exc_info=True)
return JSONResponse(
{"success": False, "error": str(e)},
status_code=500,
)
@requires("authenticated", redirect="oauth_login")
async def chunk_context_endpoint(request: Request) -> JSONResponse:
"""Fetch chunk text with surrounding context for visualization.
This endpoint retrieves the matched chunk along with surrounding text
to provide context for the search result. Used by the viz pane to
display chunks inline.
Query parameters:
doc_type: Document type (e.g., "note")
doc_id: Document ID
start: Chunk start offset (character position)
end: Chunk end offset (character position)
context: Characters of context before/after (default: 500)
Returns:
JSON with chunk_text, before_context, after_context, and flags
"""
try:
# Get query parameters
doc_type = request.query_params.get("doc_type")
doc_id = request.query_params.get("doc_id")
start_str = request.query_params.get("start")
end_str = request.query_params.get("end")
context_chars = int(request.query_params.get("context", "500"))
# Validate required parameters
if not all([doc_type, doc_id, start_str, end_str]):
return JSONResponse(
{
"success": False,
"error": "Missing required parameters: doc_type, doc_id, start, end",
},
status_code=400,
)
# Type assertions - we validated these above
assert doc_type is not None
assert doc_id is not None
assert start_str is not None
assert end_str is not None
start = int(start_str)
end = int(end_str)
# Convert doc_id to int (all document types use int IDs)
doc_id_int = int(doc_id)
# Get authenticated Nextcloud client
from nextcloud_mcp_server.auth.userinfo_routes import (
_get_authenticated_client_for_userinfo,
)
from nextcloud_mcp_server.search.context import get_chunk_with_context
# Use context expansion module to fetch chunk with surrounding context
async with await _get_authenticated_client_for_userinfo(request) as nc_client:
chunk_context = await get_chunk_with_context(
nc_client=nc_client,
user_id=request.user.display_name, # User ID from auth
doc_id=doc_id_int,
doc_type=doc_type,
chunk_start=start,
chunk_end=end,
context_chars=context_chars,
)
# Check if context expansion succeeded
if chunk_context is None:
return JSONResponse(
{
"success": False,
"error": f"Failed to fetch chunk context for {doc_type} {doc_id}",
},
status_code=404,
)
logger.info(
f"Fetched chunk context for {doc_type}_{doc_id}: "
f"chunk_len={len(chunk_context.chunk_text)}, "
f"before_len={len(chunk_context.before_context)}, "
f"after_len={len(chunk_context.after_context)}"
)
# For PDF files, also fetch the highlighted page image from Qdrant
highlighted_page_image = None
page_number = None
if doc_type == "file":
try:
from qdrant_client.models import FieldCondition, Filter, MatchValue
settings = get_settings()
qdrant_client = await get_qdrant_client()
username = request.user.display_name
# Query for this specific chunk's highlighted image
points_response = await qdrant_client.scroll(
collection_name=settings.get_collection_name(),
scroll_filter=Filter(
must=[
get_placeholder_filter(),
FieldCondition(
key="doc_id", match=MatchValue(value=doc_id_int)
),
FieldCondition(
key="user_id", match=MatchValue(value=username)
),
FieldCondition(
key="chunk_start_offset", match=MatchValue(value=start)
),
FieldCondition(
key="chunk_end_offset", match=MatchValue(value=end)
),
]
),
limit=1,
with_vectors=False,
with_payload=["highlighted_page_image", "page_number"],
)
points = points_response[0]
if points and points[0].payload:
highlighted_page_image = points[0].payload.get(
"highlighted_page_image"
)
page_number = points[0].payload.get("page_number")
if highlighted_page_image:
logger.info(
f"Found highlighted image for chunk: "
f"page={page_number}, image_size={len(highlighted_page_image)}"
)
except Exception as e:
logger.warning(f"Failed to fetch highlighted image: {e}")
# Return response compatible with frontend expectations
response_data: dict = {
"success": True,
"chunk_text": chunk_context.chunk_text,
"before_context": chunk_context.before_context,
"after_context": chunk_context.after_context,
"has_more_before": chunk_context.has_before_truncation,
"has_more_after": chunk_context.has_after_truncation,
}
# Add image data if available
if highlighted_page_image:
response_data["highlighted_page_image"] = highlighted_page_image
response_data["page_number"] = page_number
return JSONResponse(response_data)
except ValueError as e:
logger.error(f"Invalid parameter format: {e}")
return JSONResponse(
{"success": False, "error": f"Invalid parameter format: {e}"},
status_code=400,
)
except Exception as e:
logger.error(f"Chunk context error: {e}", exc_info=True)
return JSONResponse(
{"success": False, "error": str(e)},
status_code=500,
)