Upd textbook fetcher

app/db.py

@@ -30,4 +30,15 @@ async def save_to_textbook_fs(doc_id: str, file_path: str):
         # Log
         logger.info(f"📦 PDF also stored to textbook bucket at: {TEXTBOOK_URI}")
     except Exception as e:
-        logger.warning(f"⚠️ Failed to save to textbook storage: {e}")
+        logger.warning(f"⚠️ Failed to save to textbook storage: {e}")
+
+# == PDF FETCHER ==
+async def fetch_textbook_pdf(doc_id: str):
+    try:
+        textbook_client = AsyncIOMotorClient(TEXTBOOK_URI)
+        textbook_db = textbook_client.get_default_database()
+        textbook_fs = AsyncIOMotorGridFSBucket(textbook_db)
+        return await textbook_fs.open_download_stream_by_name(f"{doc_id}.pdf")
+    except Exception as e:
+        logger.warning(f"⚠️ Failed to fetch textbook PDF for {doc_id}: {e}")
+        raise

app/routers/import_doc.py

@@ -1,7 +1,8 @@
-# app/routers/import.py
+# app/routers/import_doc.py
 from fastapi import APIRouter, HTTPException
+from fastapi.responses import StreamingResponse
 from pydantic import BaseModel
-from app.db import get_db, get_gridfs, save_to_textbook_fs
+from app.db import get_db, get_gridfs, save_to_textbook_fs, fetch_textbook_pdf
 from app.services import google_books, open_library, internet_archive, project_gutenberg
 from app.services.ingest import parse_and_index
 import aiofiles, uuid, os
@@ -19,6 +20,7 @@ class ImportRequest(BaseModel):
     source: str
     ref: dict
 
+# Embedding, query and PDF saver to buckets
 @router.post("")
 async def import_book(req: ImportRequest):
     logger.info(f"📥 Received import request: {req.dict()}")
@@ -84,3 +86,12 @@ async def import_book(req: ImportRequest):
     logger.info(f"📚 Document {req.candidate_id} queued for indexing")
     return {"document_id": req.candidate_id, "status": "queued"}
 
+# Fetch textbook on id
+@router.get("/textbook/{doc_id}")
+async def get_textbook(doc_id: str):
+    try:
+        stream = await fetch_textbook_pdf(doc_id)
+        return StreamingResponse(stream, media_type="application/pdf")
+    except Exception as e:
+        logger.error(f"❌ Failed to serve textbook {doc_id}: {e}")
+        raise HTTPException(404, "Textbook not found")