"""Unit tests for fast-alpr result parsing — no model weights required (the objects
are duck-typed stand-ins shaped like fast-alpr's ALPRResult)."""

from __future__ import annotations

from types import SimpleNamespace

from vision_service.recognizer import _reduce_confidence, plate_from_alpr_result


def test_reduce_confidence_takes_min_of_list() -> None:
    # The weakest character governs trust in the whole plate.
    assert _reduce_confidence([0.99, 0.80, 0.95]) == 0.80


def test_reduce_confidence_handles_scalar_and_junk() -> None:
    assert _reduce_confidence(0.7) == 0.7
    assert _reduce_confidence(None) == 0.0
    assert _reduce_confidence([]) == 0.0
    assert _reduce_confidence("nope") == 0.0


def _fake_result(text: str, conf: list[float], region: str | None = None) -> SimpleNamespace:
    box = SimpleNamespace(x1=10, y1=20, x2=110, y2=60)
    return SimpleNamespace(
        ocr=SimpleNamespace(text=text, confidence=conf, region=region),
        detection=SimpleNamespace(bounding_box=box),
    )


def test_plate_from_result_maps_fields() -> None:
    plate = plate_from_alpr_result(_fake_result("5AU5341", [0.999, 0.9995, 0.97], "Czech Republic"))
    assert plate is not None
    assert plate.text == "5AU5341"
    assert plate.confidence == 0.97  # min of the per-character list
    assert plate.region == "Czech Republic"
    assert plate.bbox is not None
    assert (plate.bbox.x1, plate.bbox.y1, plate.bbox.x2, plate.bbox.y2) == (10, 20, 110, 60)


def test_plate_from_result_skips_empty_text() -> None:
    assert plate_from_alpr_result(_fake_result("", [0.9])) is None
    assert plate_from_alpr_result(SimpleNamespace(ocr=None, detection=None)) is None