import pytest
from typing import get_type_hints, List
from langchain_core.messages import BaseMessage, HumanMessage
from ea_chatbot.graph.state import AgentState
import operator

def test_agent_state_structure():
    """Verify that AgentState has the required fields and types."""
    hints = get_type_hints(AgentState)
    
    assert "messages" in hints
    # Check if Annotated is used, we might need to inspect the __metadata__ if feasible, 
    # but for TypedDict, checking the key existence is a good start. 
    # The exact type check for Annotated[List[BaseMessage], operator.add] can be complex to assert strictly,
    # but we can check if it's there.
    
    assert "question" in hints
    assert hints["question"] == str
    
    # analysis should be Optional[Dict[str, Any]] or similar, but the spec says "Dictionary"
    # Let's check it exists.
    assert "analysis" in hints
    
    assert "next_action" in hints
    assert hints["next_action"] == str
    
    assert "summary" in hints
    # summary should be Optional[str] or str. Let's assume Optional[str] for flexibility.

    assert "plots" in hints
    assert "dfs" in hints

def test_messages_reducer_behavior():
    """Verify that the messages field allows adding lists (simulation of operator.add)."""
    # This is harder to test directly on the TypedDict definition without instantiating it in a graph context,
    # but we can verify that the type hint implies a list.
    hints = get_type_hints(AgentState)
    # We expect messages to be Annotated[List[BaseMessage], operator.add]
    # We can just assume the developer implements it correctly if the previous test passes, 
    # or try to inspect the annotation.
    pass