added graph builder, states, nodes

src/langgraphagenticai/graph/graph_builder.py

@@ -0,0 +1,31 @@
+from langgraph.graph import StateGraph, START, END, MessagesState
+from langgraph.prebuilt import tools_condition, tool_node
+from langchain_core.prompts import ChatPromptTemplate
+from src.langgraphagenticai.state.state import State
+from src.langgraphagenticai.nodes.basic_chatbot_node import BasicChatbotNode
+
+
+class GraphBuilder:
+    def __init__(self, model):
+        self.llm = model
+        self.graph_builder = StateGraph(State)
+
+    def basic_chatbot_build_graph(self):
+        """
+        Builds a basic chatbot graph using LangGraph.
+        This method initializes a chatbot node using the `BasicChatbotNode` class
+        and integrates it into the graph. The chatbot node is set as both the
+        entry and exi point of the graph.
+        """
+        self.basic_chatbot_node = BasicChatbotNode(self.llm)
+        self.graph_builder.add_node("chatbot", self.basic_chatbot_node.process)
+        self.graph_builder.add_edge(START, "chatbot")
+        self.graph_builder.add_edge("chatbot", END)
+
+    def setup_graph(self, usecase: str):
+        """
+        Sets up the graph for the selected use case.
+        """
+        if usecase == "Basic Chatbot":
+            self.basic_chatbot_build_graph()
+        return self.graph_builder.compile()

src/langgraphagenticai/main.py

@@ -3,6 +3,7 @@ import json
 
 from src.langgraphagenticai.ui.streamlit.load_ui import LoadStreamlitUI
 from src.langgraphagenticai.llms.groq_llm import GroqChatLLM
+from src.langgraphagenticai.graph.graph_builder import GraphBuilder
 
 # MAIN function start
 def load_langgraph_agenticai_app():
@@ -45,6 +46,11 @@ def load_langgraph_agenticai_app():
 
             ## Graph builder
             graph_builder = GraphBuilder(model)
+            try:
+                graph = graph_builder.setup_graph(usecase)
+            except Exception as e:
+                st.error(f"Error: Graph setup failed - {e}")
+                return
 
         except Exception as e:
             raise ValueError(f"Error Occurred with Exception: {e}")

src/langgraphagenticai/nodes/basic_chatbot_node.py

@@ -0,0 +1,14 @@
+from src.langgraphagenticai.state.state import State
+
+class BasicChatbotNode:
+    """
+    Basic chatbot logic implementation
+    """
+    def __init__(self, model):
+        self.llm = model
+
+    def process(self, state: State) -> dict:
+        """
+        Processes the input state and generates a chatbot response.
+        """
+        return {"message": self.llm.invoke(state['messages'])}

src/langgraphagenticai/state/state.py

@@ -0,0 +1,11 @@
+from typing import Annotated, Literal, Optional
+from typing_extensions import TypedDict
+from langgraph.graph.message import add_messages
+from typing import TypedDict, Annotated, List
+from langchain_core.messages import HumanMessage, AIMessage
+
+class State(TypedDict):
+    """
+    Represents the structure of the state used in the graph.
+    """
+    messages: Annotated[list, add_messages]