from __future__ import annotations

import tempfile
import unittest
from pathlib import Path
from unittest.mock import patch

from PIL import Image

from production_build_agents.tools.face_detection import detect_faces


def _candidate(*, score: float, size: float = 48) -> list[float]:
    return [8, 8, size, size, *([0.0] * 10), score]


class FaceDetectionTest(unittest.TestCase):
    def _detect(
        self,
        candidates: list[list[float]],
    ) -> dict:
        with tempfile.TemporaryDirectory() as temp_dir:
            root = Path(temp_dir)
            source = root / "source.png"
            Image.new("RGB", (128, 96), "white").save(source)
            with patch(
                "production_build_agents.tools.face_detection"
                "._detect_candidates",
                return_value=candidates,
            ):
                return detect_faces(source.as_posix(), output_dir=root / "out")

    def test_face_decision_requires_confident_visible_face(self) -> None:
        result = self._detect([_candidate(score=0.91)])

        self.assertEqual(result["decision"], "FACE")
        self.assertEqual(result["face_count"], 1)
        self.assertEqual(result["candidate_count"], 1)
        self.assertTrue(result["faces"][0]["accepted"])
        self.assertEqual(len(result["input_sha256"]), 64)
        self.assertEqual(len(result["model_sha256"]), 64)

    def test_no_candidate_is_no_face(self) -> None:
        result = self._detect([])

        self.assertEqual(result["decision"], "NO_FACE")
        self.assertEqual(result["face_count"], 0)
        self.assertEqual(result["candidate_count"], 0)

    def test_low_confidence_or_tiny_candidate_is_uncertain(self) -> None:
        for candidate in (
            _candidate(score=0.55),
            _candidate(score=0.91, size=12),
        ):
            with self.subTest(candidate=candidate):
                result = self._detect([candidate])
                self.assertEqual(result["decision"], "UNCERTAIN")
                self.assertEqual(result["face_count"], 0)