cmbot/tests/test_composer.py

"""Tests for core.composer — no GUI dependency."""
import shutil
import sys
import tempfile
import unittest
from pathlib import Path

from PIL import Image

sys.path.insert(0, str(Path(__file__).parent.parent / "src"))

from core.composer import compose
from core.models import ExportOptions, TransformState

# ---------------------------------------------------------------------------
# helpers
# ---------------------------------------------------------------------------

def _rgba(w, h, color=(200, 200, 200, 255)):
    return Image.new("RGBA", (w, h), color)


class _TmpDir:
    def setUp(self):
        self.tmp = Path(tempfile.mkdtemp())

    def tearDown(self):
        shutil.rmtree(str(self.tmp), ignore_errors=True)

    def _save(self, img: Image.Image, name: str) -> Path:
        p = self.tmp / name
        img.save(str(p))
        return p

    def _compose(self, garment, print_img, state, fmt="PNG", quality=90):
        ext = ".jpg" if fmt.upper() in ("JPG", "JPEG") else ".png"
        g = self._save(garment, "garment.png")   # garment always PNG
        p = self._save(print_img, "print.png")
        out = self.tmp / ("out" + ext)
        opts = ExportOptions(output_format=fmt, quality=quality)
        return compose(g, p, state, opts, out), out


# ---------------------------------------------------------------------------
# Transparency tests
# ---------------------------------------------------------------------------

class TestTransparency(_TmpDir, unittest.TestCase):
    def test_fully_transparent_print_leaves_garment_unchanged(self):
        """An all-alpha-0 print must not modify the garment pixels."""
        garment = _rgba(100, 100, (200, 200, 200, 255))
        print_img = Image.new("RGBA", (40, 40), (255, 0, 0, 0))  # fully transparent

        state = TransformState(x=30, y=30, width=40, height=40)
        result, out_path = self._compose(garment, print_img, state)

        self.assertTrue(result.success, result.error)
        out = Image.open(str(out_path)).convert("RGBA")
        r, g, b, _ = out.getpixel((50, 50))
        self.assertEqual((r, g, b), (200, 200, 200))

    def test_opaque_print_overwrites_garment_pixels(self):
        """Fully opaque blue print should cover garment in the print area."""
        garment = _rgba(100, 100, (200, 200, 200, 255))
        print_img = _rgba(20, 20, (0, 0, 255, 255))

        state = TransformState(x=40, y=40, width=20, height=20)
        result, out_path = self._compose(garment, print_img, state)

        self.assertTrue(result.success, result.error)
        out = Image.open(str(out_path)).convert("RGBA")
        r, g, b, _ = out.getpixel((50, 50))   # center of print area
        self.assertEqual((r, g, b), (0, 0, 255))


# ---------------------------------------------------------------------------
# Scaling tests
# ---------------------------------------------------------------------------

class TestScaling(_TmpDir, unittest.TestCase):
    def test_print_is_scaled_to_state_dimensions(self):
        """A 10×10 print scaled to 60×80 should fill that region."""
        garment = _rgba(200, 200)
        print_img = _rgba(10, 10, (255, 0, 0, 255))

        state = TransformState(x=70, y=60, width=60, height=80)
        result, out_path = self._compose(garment, print_img, state)

        self.assertTrue(result.success, result.error)
        out = Image.open(str(out_path)).convert("RGBA")
        # Inside print area → red
        r, g, b, _ = out.getpixel((100, 100))
        self.assertEqual((r, g, b), (255, 0, 0))
        # Outside print area → garment gray
        r2, g2, b2, _ = out.getpixel((10, 10))
        self.assertEqual((r2, g2, b2), (200, 200, 200))

    def test_output_dimensions_match_garment(self):
        """Output size must always equal the garment size, regardless of print size."""
        gw, gh = 320, 480
        garment = _rgba(gw, gh)
        print_img = _rgba(10, 10, (0, 255, 0, 255))

        state = TransformState(x=100, y=100, width=80, height=80)
        result, out_path = self._compose(garment, print_img, state)

        self.assertTrue(result.success, result.error)
        out = Image.open(str(out_path))
        self.assertEqual(out.size, (gw, gh))


# ---------------------------------------------------------------------------
# Rotation centre tests
# ---------------------------------------------------------------------------

class TestRotation(_TmpDir, unittest.TestCase):
    def test_rotation_centre_fixed_for_square(self):
        """After 90° CW rotation of a square print, its centre stays at (cx, cy)."""
        garment = _rgba(200, 200)
        print_img = _rgba(20, 20, (255, 0, 0, 255))

        # Centre = (90+10, 90+10) = (100, 100)
        state = TransformState(x=90, y=90, width=20, height=20, rotation=90)
        result, out_path = self._compose(garment, print_img, state)

        self.assertTrue(result.success, result.error)
        out = Image.open(str(out_path)).convert("RGBA")
        r, g, b, _ = out.getpixel((100, 100))
        self.assertEqual((r, g, b), (255, 0, 0), "Centre pixel must be from the print")

    def test_zero_rotation_same_as_no_rotation(self):
        """rotation=0 should produce the same result as not specifying rotation."""
        garment = _rgba(100, 100)
        print_img = _rgba(20, 20, (0, 0, 255, 255))

        state = TransformState(x=40, y=40, width=20, height=20, rotation=0)
        result, out_path = self._compose(garment, print_img, state)

        self.assertTrue(result.success, result.error)
        out = Image.open(str(out_path)).convert("RGBA")
        r, g, b, _ = out.getpixel((50, 50))
        self.assertEqual((r, g, b), (0, 0, 255))


# ---------------------------------------------------------------------------
# Edge cases
# ---------------------------------------------------------------------------

class TestEdgeCases(_TmpDir, unittest.TestCase):
    def test_print_partially_outside_canvas_no_error(self):
        """Print whose bounding box extends beyond the canvas should not raise."""
        garment = _rgba(50, 50)
        print_img = _rgba(20, 20, (255, 0, 0, 255))

        state = TransformState(x=45, y=45, width=20, height=20)
        result, _ = self._compose(garment, print_img, state)
        self.assertTrue(result.success, result.error)

    def test_invalid_zero_dimensions_returns_failure(self):
        """width=0 or height=0 must return a ComposeResult with success=False."""
        garment = _rgba(100, 100)
        print_img = _rgba(10, 10)

        g = self._save(garment, "g.png")
        p = self._save(print_img, "p.png")
        out = self.tmp / "out.png"

        state = TransformState(x=0, y=0, width=0, height=0)
        result = compose(g, p, state, ExportOptions(), out)

        self.assertFalse(result.success)
        self.assertTrue(result.error)

    def test_missing_garment_file_returns_failure(self):
        """Non-existent garment path must return failure without raising."""
        p = self._save(_rgba(10, 10), "p.png")
        out = self.tmp / "out.png"

        state = TransformState(x=0, y=0, width=10, height=10)
        result = compose(self.tmp / "no_such_file.png", p, state, ExportOptions(), out)

        self.assertFalse(result.success)


# ---------------------------------------------------------------------------
# JPG output
# ---------------------------------------------------------------------------

class TestJpgOutput(_TmpDir, unittest.TestCase):
    def test_jpg_export_creates_file(self):
        garment = _rgba(100, 100)
        print_img = _rgba(30, 30, (0, 200, 0, 255))

        state = TransformState(x=35, y=35, width=30, height=30)
        result, out_path = self._compose(garment, print_img, state, fmt="JPG")

        self.assertTrue(result.success, result.error)
        self.assertTrue(out_path.exists())

    def test_jpg_export_no_alpha_error(self):
        """JPG export must not raise due to alpha channel handling."""
        garment = _rgba(80, 80, (255, 255, 255, 255))
        print_img = Image.new("RGBA", (20, 20), (255, 0, 0, 128))  # semi-transparent

        state = TransformState(x=30, y=30, width=20, height=20)
        result, _ = self._compose(garment, print_img, state, fmt="JPG")
        self.assertTrue(result.success, result.error)


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