import base64

import pytest

from app.detector import MockDetector

# 1x1 透明 PNG
TINY_PNG = base64.b64decode(
    "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg=="
)


def test_mock_detector_returns_canned_detection():
    det = MockDetector(class_name="sick", confidence=0.92)
    result = det.detect(TINY_PNG)
    assert len(result) == 1
    assert result[0]["class_name"] == "sick"
    assert result[0]["confidence"] == 0.92
    assert result[0]["bbox"]["w"] > 0


def test_mock_detector_rejects_invalid_image():
    det = MockDetector()
    with pytest.raises(ValueError):
        det.detect(b"not an image")