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library-desk/src/services/rag_search_service.py
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jpmschweitzerandClaude Opus 4.5 61863ff597
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feat: add RAG search endpoint with content extraction
- Add /rag/search endpoint for web, news, and image search via SearXNG
- Add /content/extract and /content/extract/batch endpoints
- Add ContentExtractor client using Trafilatura for content extraction
- Enhance HybridRAG web search with full content extraction
- Add Redis caching for search results
- Add new configuration options for search and extraction timeouts

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2025-12-15 15:50:48 +01:00

266 lines
8.1 KiB
Python

"""
RAG Search service for Library Desk.
Provides web, news, and image search with content extraction:
- Uses SearXNG for search queries
- Uses Trafilatura for content extraction
- Caches results in Redis
"""
import hashlib
import json
import logging
import time
from typing import List, Optional
from urllib.parse import urlparse
import redis.asyncio as aioredis
from src.clients.searxng_client import SearXNGClient
from src.clients.content_extractor import ContentExtractor
from src.config import Settings
from src.models.rag_search import (
SearchType,
RAGSearchRequest,
RAGSearchResult,
RAGSearchResponse,
)
logger = logging.getLogger(__name__)
def extract_domain(url: str) -> str:
"""Extract domain name from URL, removing 'www.' prefix."""
try:
parsed = urlparse(url)
domain = parsed.netloc
return domain.removeprefix("www.")
except Exception:
return url
class RAGSearchService:
"""
Service for RAG-optimized web search with content extraction.
Combines SearXNG search with Trafilatura content extraction
and Redis caching for efficient RAG pipeline integration.
"""
def __init__(
self,
searxng_client: SearXNGClient,
content_extractor: ContentExtractor,
redis_client: aioredis.Redis,
settings: Settings
):
"""
Initialize RAG search service.
Args:
searxng_client: SearXNG search client
content_extractor: Trafilatura content extractor
redis_client: Async Redis client for caching
settings: Application settings
"""
self.searxng = searxng_client
self.extractor = content_extractor
self.redis = redis_client
self.settings = settings
self.cache_ttl = settings.search_cache_ttl
self.default_limit = settings.search_default_limit
logger.info(
f"Initialized RAGSearchService: cache_ttl={self.cache_ttl}s, "
f"default_limit={self.default_limit}"
)
def _cache_key(self, query: str, search_type: str, limit: int) -> str:
"""Generate cache key from search parameters."""
key_data = f"{query}:{search_type}:{limit}"
key_hash = hashlib.md5(key_data.encode()).hexdigest()
return f"rag_search:{key_hash}"
async def _get_cached_result(self, cache_key: str) -> Optional[RAGSearchResponse]:
"""Try to get cached search result."""
try:
cached = await self.redis.get(cache_key)
if cached:
data = json.loads(cached)
logger.debug(f"Cache hit: {cache_key}")
return RAGSearchResponse(**data)
except Exception as e:
logger.warning(f"Cache read failed: {e}")
return None
async def _set_cached_result(self, cache_key: str, result: RAGSearchResponse):
"""Cache search result."""
try:
await self.redis.setex(
cache_key,
self.cache_ttl,
result.model_dump_json()
)
logger.debug(f"Cached result: {cache_key} (TTL={self.cache_ttl}s)")
except Exception as e:
logger.warning(f"Cache write failed: {e}")
async def _search_searxng(
self,
query: str,
search_type: SearchType,
limit: int
) -> List[dict]:
"""Execute search via SearXNG based on search type."""
try:
if search_type == SearchType.WEB:
results = await self.searxng.search_general(
query=query,
limit=limit
)
elif search_type == SearchType.NEWS:
results = await self.searxng.search_news(
query=query,
limit=limit
)
elif search_type == SearchType.IMAGES:
results = await self.searxng.search_images(
query=query,
limit=limit
)
else:
results = await self.searxng.search_general(
query=query,
limit=limit
)
return results
except Exception as e:
logger.error(f"SearXNG search failed: {e}")
raise
async def _extract_content_for_results(
self,
results: List[dict]
) -> List[RAGSearchResult]:
"""Extract full content from search result URLs."""
# Get URLs for extraction
urls = [r.get("url", "") for r in results if r.get("url")]
# Extract content in parallel
extraction_results = await self.extractor.extract_batch(urls)
# Build result objects
search_results = []
for i, raw_result in enumerate(results):
url = raw_result.get("url", "")
# Find matching extraction result
extracted_content = ""
for ext_result in extraction_results:
if ext_result.url == url and ext_result.success:
extracted_content = ext_result.content
break
# Get original snippet
snippet = raw_result.get("content", "")
if len(snippet) > 300:
snippet = snippet[:300] + "..."
# Build result
search_results.append(RAGSearchResult(
title=raw_result.get("title", ""),
url=url,
content=extracted_content,
snippet=snippet,
source=extract_domain(url),
published_date=raw_result.get("publishedDate")
))
return search_results
def _generate_sources_summary(self, results: List[RAGSearchResult]) -> str:
"""Generate markdown list of source URLs."""
if not results:
return ""
lines = ["## Sources"]
for i, r in enumerate(results, 1):
lines.append(f"{i}. [{r.title}]({r.url})")
return "\n".join(lines)
async def search(
self,
query: str,
search_type: SearchType = SearchType.WEB,
limit: Optional[int] = None,
user: str = "default"
) -> RAGSearchResponse:
"""
Execute RAG-optimized search.
Args:
query: Search query string
search_type: Type of search (web, news, images)
limit: Maximum results to return (default from settings)
user: User identifier for logging/rate limiting
Returns:
RAGSearchResponse with extracted content and sources
Raises:
ValueError: If query is empty
Exception: If search fails
"""
start_time = time.time()
if not query or not query.strip():
raise ValueError("Query cannot be empty")
effective_limit = limit or self.default_limit
# Check cache
cache_key = self._cache_key(query, search_type.value, effective_limit)
cached = await self._get_cached_result(cache_key)
if cached:
return cached
logger.info(
f"RAG search: '{query}' type={search_type.value} "
f"limit={effective_limit} user={user}"
)
# Execute search
raw_results = await self._search_searxng(query, search_type, effective_limit)
# Extract content from results
search_results = await self._extract_content_for_results(raw_results)
# Generate sources summary
sources_summary = self._generate_sources_summary(search_results)
# Calculate timing
search_time_ms = int((time.time() - start_time) * 1000)
# Build response
response = RAGSearchResponse(
query=query,
search_type=search_type,
results=search_results,
total_results=len(search_results),
search_time_ms=search_time_ms,
sources_summary=sources_summary
)
# Cache result
await self._set_cached_result(cache_key, response)
logger.info(
f"RAG search completed: {len(search_results)} results "
f"in {search_time_ms}ms"
)
return response