chrysopedia/backend/search_service.py
jlightner c0df369018 feat: Created async search service with embedding+Qdrant+keyword fallba…
- "backend/search_service.py"
- "backend/schemas.py"
- "backend/routers/search.py"
- "backend/routers/techniques.py"
- "backend/routers/topics.py"
- "backend/routers/creators.py"
- "backend/main.py"

GSD-Task: S05/T01
2026-03-29 23:55:52 +00:00

337 lines
12 KiB
Python

"""Async search service for the public search endpoint.
Orchestrates semantic search (embedding + Qdrant) with keyword fallback.
All external calls have timeouts and graceful degradation — if embedding
or Qdrant fail, the service falls back to keyword-only (ILIKE) search.
"""
from __future__ import annotations
import asyncio
import logging
import time
from typing import Any
import openai
from qdrant_client import AsyncQdrantClient
from qdrant_client.http import exceptions as qdrant_exceptions
from qdrant_client.models import FieldCondition, Filter, MatchValue
from sqlalchemy import or_, select
from sqlalchemy.ext.asyncio import AsyncSession
from config import Settings
from models import Creator, KeyMoment, TechniquePage
logger = logging.getLogger("chrysopedia.search")
# Timeout for external calls (embedding API, Qdrant) in seconds
_EXTERNAL_TIMEOUT = 0.3 # 300ms per plan
class SearchService:
"""Async search service with semantic + keyword fallback.
Parameters
----------
settings:
Application settings containing embedding and Qdrant config.
"""
def __init__(self, settings: Settings) -> None:
self.settings = settings
self._openai = openai.AsyncOpenAI(
base_url=settings.embedding_api_url,
api_key=settings.llm_api_key,
)
self._qdrant = AsyncQdrantClient(url=settings.qdrant_url)
self._collection = settings.qdrant_collection
# ── Embedding ────────────────────────────────────────────────────────
async def embed_query(self, text: str) -> list[float] | None:
"""Embed a query string into a vector.
Returns None on any failure (timeout, connection, malformed response)
so the caller can fall back to keyword search.
"""
try:
response = await asyncio.wait_for(
self._openai.embeddings.create(
model=self.settings.embedding_model,
input=text,
),
timeout=_EXTERNAL_TIMEOUT,
)
except asyncio.TimeoutError:
logger.warning("Embedding API timeout (%.0fms limit) for query: %.50s", _EXTERNAL_TIMEOUT * 1000, text)
return None
except (openai.APIConnectionError, openai.APITimeoutError) as exc:
logger.warning("Embedding API connection error (%s: %s)", type(exc).__name__, exc)
return None
except openai.APIError as exc:
logger.warning("Embedding API error (%s: %s)", type(exc).__name__, exc)
return None
if not response.data:
logger.warning("Embedding API returned empty data for query: %.50s", text)
return None
vector = response.data[0].embedding
if len(vector) != self.settings.embedding_dimensions:
logger.warning(
"Embedding dimension mismatch: expected %d, got %d",
self.settings.embedding_dimensions,
len(vector),
)
return None
return vector
# ── Qdrant vector search ─────────────────────────────────────────────
async def search_qdrant(
self,
vector: list[float],
limit: int = 20,
type_filter: str | None = None,
) -> list[dict[str, Any]]:
"""Search Qdrant for nearest neighbours.
Returns a list of dicts with 'score' and 'payload' keys.
Returns empty list on failure.
"""
query_filter = None
if type_filter:
query_filter = Filter(
must=[FieldCondition(key="type", match=MatchValue(value=type_filter))]
)
try:
results = await asyncio.wait_for(
self._qdrant.query_points(
collection_name=self._collection,
query=vector,
query_filter=query_filter,
limit=limit,
with_payload=True,
),
timeout=_EXTERNAL_TIMEOUT,
)
except asyncio.TimeoutError:
logger.warning("Qdrant search timeout (%.0fms limit)", _EXTERNAL_TIMEOUT * 1000)
return []
except qdrant_exceptions.UnexpectedResponse as exc:
logger.warning("Qdrant search error: %s", exc)
return []
except Exception as exc:
logger.warning("Qdrant connection error (%s: %s)", type(exc).__name__, exc)
return []
return [
{"score": point.score, "payload": point.payload}
for point in results.points
]
# ── Keyword fallback ─────────────────────────────────────────────────
async def keyword_search(
self,
query: str,
scope: str,
limit: int,
db: AsyncSession,
) -> list[dict[str, Any]]:
"""ILIKE keyword search across technique pages, key moments, and creators.
Searches title/name columns. Returns a unified list of result dicts.
"""
results: list[dict[str, Any]] = []
pattern = f"%{query}%"
if scope in ("all", "topics"):
stmt = (
select(TechniquePage)
.where(
or_(
TechniquePage.title.ilike(pattern),
TechniquePage.summary.ilike(pattern),
)
)
.limit(limit)
)
rows = await db.execute(stmt)
for tp in rows.scalars().all():
results.append({
"type": "technique_page",
"title": tp.title,
"slug": tp.slug,
"summary": tp.summary or "",
"topic_category": tp.topic_category,
"topic_tags": tp.topic_tags or [],
"creator_id": str(tp.creator_id),
"score": 0.0,
})
if scope in ("all",):
km_stmt = (
select(KeyMoment)
.where(KeyMoment.title.ilike(pattern))
.limit(limit)
)
km_rows = await db.execute(km_stmt)
for km in km_rows.scalars().all():
results.append({
"type": "key_moment",
"title": km.title,
"slug": "",
"summary": km.summary or "",
"topic_category": "",
"topic_tags": [],
"creator_id": "",
"score": 0.0,
})
if scope in ("all", "creators"):
cr_stmt = (
select(Creator)
.where(Creator.name.ilike(pattern))
.limit(limit)
)
cr_rows = await db.execute(cr_stmt)
for cr in cr_rows.scalars().all():
results.append({
"type": "creator",
"title": cr.name,
"slug": cr.slug,
"summary": "",
"topic_category": "",
"topic_tags": cr.genres or [],
"creator_id": str(cr.id),
"score": 0.0,
})
return results[:limit]
# ── Orchestrator ─────────────────────────────────────────────────────
async def search(
self,
query: str,
scope: str,
limit: int,
db: AsyncSession,
) -> dict[str, Any]:
"""Run semantic search with keyword fallback.
Returns a dict matching the SearchResponse schema shape.
"""
start = time.monotonic()
# Validate / sanitize inputs
if not query or not query.strip():
return {"items": [], "total": 0, "query": query, "fallback_used": False}
# Truncate long queries
query = query.strip()[:500]
# Normalize scope
if scope not in ("all", "topics", "creators"):
scope = "all"
# Map scope to Qdrant type filter
type_filter_map = {
"all": None,
"topics": "technique_page",
"creators": None, # creators aren't in Qdrant
}
qdrant_type_filter = type_filter_map.get(scope)
fallback_used = False
items: list[dict[str, Any]] = []
# Try semantic search
vector = await self.embed_query(query)
if vector is not None:
qdrant_results = await self.search_qdrant(vector, limit=limit, type_filter=qdrant_type_filter)
if qdrant_results:
# Enrich Qdrant results with DB metadata
items = await self._enrich_results(qdrant_results, db)
# Fallback to keyword search if semantic failed or returned nothing
if not items:
items = await self.keyword_search(query, scope, limit, db)
fallback_used = True
elapsed_ms = (time.monotonic() - start) * 1000
logger.info(
"Search query=%r scope=%s results=%d fallback=%s latency_ms=%.1f",
query,
scope,
len(items),
fallback_used,
elapsed_ms,
)
return {
"items": items,
"total": len(items),
"query": query,
"fallback_used": fallback_used,
}
# ── Result enrichment ────────────────────────────────────────────────
async def _enrich_results(
self,
qdrant_results: list[dict[str, Any]],
db: AsyncSession,
) -> list[dict[str, Any]]:
"""Enrich Qdrant results with creator names and slugs from DB."""
enriched: list[dict[str, Any]] = []
# Collect creator_ids to batch-fetch
creator_ids = set()
for r in qdrant_results:
payload = r.get("payload", {})
cid = payload.get("creator_id")
if cid:
creator_ids.add(cid)
# Batch fetch creators
creator_map: dict[str, dict[str, str]] = {}
if creator_ids:
from sqlalchemy.dialects.postgresql import UUID as PgUUID
import uuid as uuid_mod
valid_ids = []
for cid in creator_ids:
try:
valid_ids.append(uuid_mod.UUID(cid))
except (ValueError, AttributeError):
pass
if valid_ids:
stmt = select(Creator).where(Creator.id.in_(valid_ids))
result = await db.execute(stmt)
for c in result.scalars().all():
creator_map[str(c.id)] = {"name": c.name, "slug": c.slug}
for r in qdrant_results:
payload = r.get("payload", {})
cid = payload.get("creator_id", "")
creator_info = creator_map.get(cid, {"name": "", "slug": ""})
enriched.append({
"type": payload.get("type", ""),
"title": payload.get("title", ""),
"slug": payload.get("slug", payload.get("title", "").lower().replace(" ", "-")),
"summary": payload.get("summary", ""),
"topic_category": payload.get("topic_category", ""),
"topic_tags": payload.get("topic_tags", []),
"creator_id": cid,
"creator_name": creator_info["name"],
"creator_slug": creator_info["slug"],
"score": r.get("score", 0.0),
})
return enriched