import pytest
from unittest.mock import MagicMock, patch
from langchain_core.messages import AIMessage
from langchain_openai import ChatOpenAI
from ea_chatbot.graph.nodes.researcher import researcher_node

@pytest.fixture
def mock_llm():
    with patch("ea_chatbot.graph.nodes.researcher.get_llm_model") as mock_get_llm:
        mock_llm_instance = MagicMock(spec=ChatOpenAI)
        mock_get_llm.return_value = mock_llm_instance
        yield mock_llm_instance

def test_researcher_node_success(mock_llm):
    """Test that researcher_node invokes LLM with web_search tool and returns messages."""
    state = {
        "question": "What is the capital of France?",
        "messages": []
    }
    
    mock_llm_with_tools = MagicMock()
    mock_llm.bind_tools.return_value = mock_llm_with_tools
    mock_llm_with_tools.invoke.return_value = AIMessage(content="The capital of France is Paris.")
    
    result = researcher_node(state)
    
    assert mock_llm.bind_tools.called
    # Check that it was called with web_search
    args, kwargs = mock_llm.bind_tools.call_args
    assert {"type": "web_search"} in args[0]
    
    assert mock_llm_with_tools.invoke.called
    assert "messages" in result
    assert result["messages"][0].content == "The capital of France is Paris."