Update app.py

app.py

@@ -3,7 +3,7 @@ import shutil
 from datetime import datetime
 
 import gradio as gr
-
+from langchain_chroma import chroma
 from langchain_community.document_loaders import PyPDFLoader
 from langchain_text_splitters import RecursiveCharacterTextSplitter
 
@@ -25,11 +25,6 @@ NOTE_FILE = "research_notes.txt"
 
 os.makedirs(PAPER_DIR, exist_ok=True)
 
-snapshot_download(
-    repo_id="yamamoto/papers",
-    repo_type="dataset",
-    local_dir=PAPER_DIR
-)
 
 # ==================================================
 # Gemini
@@ -57,6 +52,15 @@ llm = ChatGoogleGenerativeAI(
 
 def rebuild_database():
 
+    snapshot_download(
+    repo_id="yamaaa0/papers",
+    repo_type="dataset",
+    local_dir=PAPER_DIR
+    )
+    
+    if not os.path.exists(DB_DIR):
+        rebuild_database()
+    
     pdf_files = [
         os.path.join(PAPER_DIR, f)
         for f in os.listdir(PAPER_DIR)