from __future__ import annotations


def test_ask_stream_invokes_provider_once(client, monkeypatch) -> None:
    from app.routes import ask

    class CountingProvider:
        model_name = "counting-provider"
        is_fallback = False

        def __init__(self) -> None:
            self.streaming_calls = 0

        def generate_streaming(self, **_kwargs):
            self.streaming_calls += 1
            yield "A fast "
            yield "answer."

    provider = CountingProvider()
    monkeypatch.setattr(ask, "get_ai_provider", lambda: provider)

    response = client.post(
        "/ask/stream",
        json={"question": "Explain resonance simply.", "language_preference": "English"},
    )

    assert response.status_code == 200
    assert "A fast " in response.text
    assert "answer." in response.text
    assert provider.streaming_calls == 1