import asyncio
from unittest.mock import MagicMock


def test_transcription_engine_is_singleton():
    from transcription import engine, TranscriptionEngine
    assert isinstance(engine, TranscriptionEngine)


def test_transcribe_file_calls_whisper(tmp_path):
    wav = tmp_path / "test.wav"
    wav.write_bytes(b"\x00" * 100)

    mock_model = MagicMock()
    mock_segment = MagicMock()
    mock_segment.text = " Hallo Welt"
    mock_model.transcribe.return_value = ([mock_segment], MagicMock())

    from transcription import TranscriptionEngine
    eng = TranscriptionEngine()
    eng._model = mock_model

    result = asyncio.run(eng.transcribe_file(str(wav), language="de"))
    assert result == "Hallo Welt"
    mock_model.transcribe.assert_called_once_with(str(wav), language="de")