"""The OCR guard must actually skip when there is no engine.

This is a regression test for a real bug: the guard in `test_cli.py` asked
`detector_available()`, whose default `auto` is `True` even with nothing
installed - because the grid fallback always exists. So on a machine with no OCR
engine the test *failed* instead of skipping, and the failure looked like a
harness defect. The guard now asks for `ocr` specifically, and here is the proof.
"""

import pytest

from conftest import require_ocr

import tiny_computer_agent.perception as perception


def test_the_guard_skips_when_no_engine_is_installed(monkeypatch):
    monkeypatch.setattr(perception, "detector_available",
                        lambda name="auto": (False, "simulated: no engine"))
    with pytest.raises(pytest.skip.Exception):
        require_ocr()


def test_the_guard_passes_when_an_engine_is_installed(monkeypatch):
    monkeypatch.setattr(perception, "detector_available",
                        lambda name="auto": (True, "simulated: engine present"))
    require_ocr()          # must not raise


def test_the_guard_asks_for_ocr_and_not_auto(monkeypatch):
    """`auto` is available with nothing installed, so it would never skip."""
    asked = []

    def record(name="auto"):
        asked.append(name)
        return True, "recorded"

    monkeypatch.setattr(perception, "detector_available", record)
    require_ocr()
    assert asked == ["ocr"]


def test_auto_is_available_without_any_engine():
    """The reason the old guard never fired, pinned down as a test."""
    available, detail = perception.detector_available("auto")
    assert available is True, "auto must stay usable with no OCR engine"