import importlib.util

import pytest

from pam_deploy_graph.graph import build_graph_or_none, build_langgraph
from pam_deploy_graph.params_loader import load_params_file


def test_build_graph_or_none_without_langgraph_is_safe():
    graph = build_graph_or_none()
    if importlib.util.find_spec("langgraph"):
        assert graph is not None
    else:
        assert graph is None


def test_build_langgraph_error_without_dependency_is_clear():
    if importlib.util.find_spec("langgraph"):
        pytest.skip("langgraph installed")
    with pytest.raises(RuntimeError, match="langgraph is not installed"):
        build_langgraph()


def test_langgraph_invokes_global_flow_when_installed(tmp_path):
    if not importlib.util.find_spec("langgraph"):
        pytest.skip("langgraph not installed")
    graph = build_langgraph(flow="global")
    result = graph.invoke(
        {
            "params": load_params_file("doc_scripts/config.txt.example"),
            "execution_strategy": "fake",
            "config_path": str(tmp_path / "config.txt"),
        }
    )
    state = result["agent_state"]
    assert state.completed_global_steps[-1] == "poll-download-progress"
    assert state.action_backends["get-online-ips"] == "fake"