Update src/app.py

src/app.py

@@ -107,7 +107,38 @@ def get_rag_chain():
     )
     return chain
 
+# In app.py
+
 def search_archives(query):
+    """
+    STRICT SEARCH LOGIC:
+    1. Runs a Pure Keyword (BM25) search first.
+    2. If it finds exact matches, it returns them immediately (ignoring Vector noise).
+    3. Only falls back to Vector search if Keywords find nothing.
+    """
+    # --- PHASE 1: PRECISE KEYWORD SEARCH ---
+    if os.path.exists(CHUNKS_FILE):
+        try:
+            with open(CHUNKS_FILE, "rb") as f:
+                chunks = pickle.load(f)
+            
+            # Create a temporary keyword retriever just for this search
+            keyword_retriever = BM25Retriever.from_documents(chunks)
+            keyword_retriever.k = 15  # Fetch top 15 exact matches
+            
+            # Run the search
+            keyword_docs = keyword_retriever.invoke(query)
+            
+            # CRITICAL CHECK: Did we find anything?
+            if keyword_docs:
+                print(f"✅ Found {len(keyword_docs)} matches via Keywords.")
+                return keyword_docs
+        except Exception as e:
+            print(f"⚠️ Keyword Search failed: {e}")
+
+    # --- PHASE 2: FALLBACK VECTOR SEARCH ---
+    # Only runs if Phase 1 returned nothing.
+    print("⚠️ No keywords found. Falling back to Vector Search...")
     retriever = get_retriever()
     docs = retriever.invoke(query)
     return docs