"""Startup model load runs on a background thread so the tray can show first (#50).

Seams covered here, all at the SpeechRecognitionManager public surface:
the deferred-load constructor flag, ``load_model_in_background`` (thread,
loading flag, callbacks, failure reporting), the dictation guard while the
model is loading, supersession by an auto-pause, and the language-shortcut
path while loading.
"""

import threading
from unittest.mock import patch

import pytest

MANAGER_MODULE = "vocalinux.speech_recognition.recognition_manager"


@pytest.fixture
def init_whispercpp():
    """Stand in for the whisper.cpp load so no model file is read."""
    from vocalinux.speech_recognition.recognition_manager import SpeechRecognitionManager

    with patch.object(SpeechRecognitionManager, "_init_whispercpp") as init:
        yield init


def _deferred_manager():
    from vocalinux.speech_recognition.recognition_manager import SpeechRecognitionManager

    return SpeechRecognitionManager(
        engine="whisper_cpp",
        model_size="small",
        language="en-us",
        defer_model_load=True,
    )


class TestDeferredConstruction:
    def test_construction_does_not_load_the_engine(self, init_whispercpp):
        manager = _deferred_manager()

        init_whispercpp.assert_not_called()
        assert manager.model_loading is True
        assert manager.model_ready is False

    def test_default_construction_still_loads_synchronously(self, init_whispercpp):
        from vocalinux.speech_recognition.recognition_manager import SpeechRecognitionManager

        manager = SpeechRecognitionManager(
            engine="whisper_cpp", model_size="small", language="en-us"
        )

        init_whispercpp.assert_called_once_with()
        assert manager.model_loading is False

    def test_unknown_engine_still_fails_at_construction(self, init_whispercpp):
        from vocalinux.speech_recognition.recognition_manager import SpeechRecognitionManager

        with pytest.raises(ValueError, match="Unsupported speech recognition engine"):
            SpeechRecognitionManager(
                engine="no-such-engine",
                model_size="small",
                language="en-us",
                defer_model_load=True,
            )


class TestBackgroundLoad:
    def test_load_runs_on_a_daemon_thread_and_returns_at_once(self, init_whispercpp):
        entered = threading.Event()
        release = threading.Event()
        seen_threads = []

        def slow_load(*_args, **_kwargs):
            seen_threads.append(threading.current_thread())
            entered.set()
            release.wait(5)

        init_whispercpp.side_effect = slow_load
        manager = _deferred_manager()

        manager.load_model_in_background()

        assert entered.wait(5), "the load never started"
        assert manager.model_loading is True
        assert seen_threads[0] is not threading.main_thread()
        assert seen_threads[0].daemon is True
        release.set()
        manager._model_load_thread.join(5)

    def test_loading_flag_clears_and_callbacks_fire_after_success(self, init_whispercpp):
        manager = _deferred_manager()
        flags_seen_by_callback = []
        manager.register_model_load_callback(
            lambda: flags_seen_by_callback.append(manager.model_loading)
        )

        manager.load_model_in_background()
        manager._model_load_thread.join(5)

        init_whispercpp.assert_called_once_with()
        assert manager.model_loading is False
        assert flags_seen_by_callback, "the load-finished callback never ran"
        assert flags_seen_by_callback[-1] is False

    def test_failed_load_reports_error_instead_of_raising(self, init_whispercpp):
        from vocalinux.common_types import RecognitionState

        init_whispercpp.side_effect = RuntimeError("model file is corrupt")
        manager = _deferred_manager()
        states = []
        manager.register_state_callback(states.append)

        with patch(f"{MANAGER_MODULE}._show_notification") as notify:
            manager.load_model_in_background()
            manager._model_load_thread.join(5)

        assert manager.model_loading is False
        assert manager.state == RecognitionState.ERROR
        assert states[-1] == RecognitionState.ERROR
        notify.assert_called_once()
        assert "failed to load" in notify.call_args.args[0].lower()

    def test_auto_pause_already_active_at_startup_skips_the_load(self, init_whispercpp):
        manager = _deferred_manager()
        # A configured app is already running when the tray comes up. Its
        # auto-pause runs before the load is scheduled, so the load must not
        # keep the model resident; auto-resume loads it when the app exits.
        manager._new_model_request(auto_pause=True)

        manager.load_model_in_background()
        manager._model_load_thread.join(5)

        init_whispercpp.assert_not_called()
        assert manager.is_auto_paused is True
        assert manager.model_loading is False

    def test_auto_pause_arriving_before_the_load_supersedes_it(self, init_whispercpp):
        manager = _deferred_manager()

        # The loader must wait for the model lock; an auto-pause takes a newer
        # request while the lock is still held, so the load must not run.
        with manager._model_lock:
            manager.load_model_in_background()
            manager._new_model_request(auto_pause=True)
        manager._model_load_thread.join(5)

        init_whispercpp.assert_not_called()
        assert manager.is_auto_paused is True
        assert manager.model_loading is False


class TestDictationWhileLoading:
    def test_start_is_refused_with_a_loading_notice(self, init_whispercpp):
        from vocalinux.common_types import RecognitionState

        manager = _deferred_manager()

        with (
            patch(f"{MANAGER_MODULE}._show_notification") as notify,
            patch(f"{MANAGER_MODULE}.play_error_sound") as error_sound,
            patch.object(manager, "_notify_model_missing") as model_missing_offer,
        ):
            started = manager.start_recognition()

        assert started is False
        assert manager.state == RecognitionState.IDLE
        model_missing_offer.assert_not_called()
        error_sound.assert_called_once()
        assert "loading" in notify.call_args.args[0].lower()
        init_whispercpp.assert_not_called()

    def test_language_shortcut_during_load_reports_loading_not_unsupported(self, init_whispercpp):
        manager = _deferred_manager()

        with (
            patch.object(manager, "_refuse_language_override") as refuse,
            patch(f"{MANAGER_MODULE}._show_notification") as notify,
            patch(f"{MANAGER_MODULE}.play_error_sound"),
        ):
            started = manager.start_recognition_with_language("de")

        assert started is False
        refuse.assert_not_called()
        assert "loading" in notify.call_args.args[0].lower()