added memory_store and search_tool [the implementation was missing]

app.py

@@ -8,6 +8,8 @@ from langgraph.prebuilt import ToolNode
 from langgraph.graph import START, StateGraph
 from langgraph.prebuilt import tools_condition
 from langchain_huggingface import HuggingFaceEndpoint, ChatHuggingFace
+from langchain.memory import ChatMessageHistory
+from langchain.memory import ConversationBufferMemory
 
 from tools import weather_info_tool, hub_stats_tool, memory_management_tool, duckduckgo_search_tool
 from retriever import load_guest_dataset
@@ -22,6 +24,9 @@ llm = HuggingFaceEndpoint(
 
 chat = ChatHuggingFace(llm=llm, verbose=True)
 
+# Initialize memory store
+memory_store = ConversationBufferMemory(memory_key="chat_history", return_messages=True)
+
 # adding tools
 
 guest_info_tool = load_guest_dataset()
@@ -41,7 +46,7 @@ def assistant(state: AgentState):
     
     # Check if the query is about an unfamiliar guest
     if "guest" in state["messages"][-1].content:
-        search_results = search_tool.forward(state["messages"][-1].content)
+        search_results = duckduckgo_search_tool.forward(state["messages"][-1].content)
         return {
             "messages": [search_results]
         }