from langchain_core.messages import SystemMessage
from langgraph.checkpoint.memory import MemorySaver
from langgraph.prebuilt import create_react_agent
from langchain_openai import ChatOpenAI

from agent.tools import think
from utils.prompt import build_prompt


def build_graph():
    tools = [
        think,
    ]
    agent = create_react_agent(
        ChatOpenAI(model="gpt-4o-mini"),
        tools,
        checkpointer=MemorySaver(),
        prompt=SystemMessage(build_prompt(tools)),
    )
    return agent