"""
NAH-9 — model fallback is a one-env-var config flip.

Re-imports llm under different RECALL_MODEL values to confirm alias resolution
and verbatim passthrough of full HF ids. No GPU/model download (we never call
_load). Run:  python3 test_model_config.py
"""
import importlib
import os


def _reload_with(model_env):
    if model_env is None:
        os.environ.pop("RECALL_MODEL", None)
    else:
        os.environ["RECALL_MODEL"] = model_env
    os.environ["RECALL_STUB"] = "1"  # keep stub on; we only check config, not GPU
    import llm
    return importlib.reload(llm)


def test_default_is_8b():
    llm = _reload_with(None)
    assert llm.MODEL_ID == "openbmb/MiniCPM4.1-8B"
    print("ok  default -> MiniCPM4.1-8B")


def test_1b_alias():
    llm = _reload_with("1b")
    assert llm.MODEL_ID == "openbmb/MiniCPM5-1B"
    print("ok  RECALL_MODEL=1b -> MiniCPM5-1B (fast fallback)")


def test_4b_alias():
    llm = _reload_with("4b")
    assert llm.MODEL_ID == "openbmb/MiniCPM3-4B"
    print("ok  RECALL_MODEL=4b -> MiniCPM3-4B (Tiny Titan)")


def test_full_id_passthrough():
    llm = _reload_with("some-org/Custom-Model-7B")
    assert llm.MODEL_ID == "some-org/Custom-Model-7B"
    print("ok  unknown value passed through as a literal HF id")


def test_active_model_reports_stub():
    llm = _reload_with("1b")
    assert llm.active_model() == "stub", "STUB on -> active_model() is 'stub'"
    print("ok  active_model() reports 'stub' while stubbed")


if __name__ == "__main__":
    test_default_is_8b()
    test_1b_alias()
    test_4b_alias()
    test_full_id_passthrough()
    test_active_model_reports_stub()
    print("\nAll NAH-9 model-config tests passed.")