import io
import unittest

from PIL import Image

from app.vision.preprocess import prepare_image


class VisionPreprocessTests(unittest.TestCase):
    def _make_png(self, width: int, height: int) -> bytes:
        buffer = io.BytesIO()
        Image.new("RGB", (width, height), color=(120, 80, 200)).save(buffer, format="PNG")
        return buffer.getvalue()

    def test_resize_large_image(self) -> None:
        raw = self._make_png(2400, 1600)
        prepared = prepare_image(raw)
        self.assertLessEqual(max(prepared.width, prepared.height), 1280)
        self.assertLess(prepared.compressed_bytes, prepared.original_bytes)

    def test_small_image_keeps_dimensions(self) -> None:
        raw = self._make_png(640, 480)
        prepared = prepare_image(raw)
        self.assertEqual(prepared.width, 640)
        self.assertEqual(prepared.height, 480)
        self.assertEqual(prepared.mime, "image/jpeg")


if __name__ == "__main__":
    unittest.main()