"""Tests for the pure parts of Tools/character_match.py."""

import os
import sys
import unittest

from PIL import Image

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
import character_match as cm  # noqa: E402


class ColourTests(unittest.TestCase):
    def test_white_is_light_and_neutral(self):
        light, a, b = cm.rgb_to_lab((255, 255, 255))
        self.assertAlmostEqual(light, 100.0, delta=0.2)
        self.assertAlmostEqual(a, 0.0, delta=0.2)
        self.assertAlmostEqual(b, 0.0, delta=0.2)

    def test_black_is_dark(self):
        self.assertAlmostEqual(cm.rgb_to_lab((0, 0, 0))[0], 0.0, delta=0.1)

    def test_identical_colours_have_no_distance(self):
        self.assertAlmostEqual(cm.delta_e76(cm.rgb_to_lab((120, 90, 70)),
                                           cm.rgb_to_lab((120, 90, 70))), 0.0, delta=1e-9)

    def test_red_green_are_far_apart(self):
        distance = cm.delta_e76(cm.rgb_to_lab((200, 40, 40)), cm.rgb_to_lab((40, 160, 40)))
        self.assertGreater(distance, 40.0)


class MaskTests(unittest.TestCase):
    def _image(self, figure_colour, background_colour):
        image = Image.new("RGB", (60, 100), background_colour)
        pixels = image.load()
        for y in range(20, 90):
            for x in range(25, 35):
                pixels[x, y] = figure_colour
        return image

    def test_saturated_figure_on_grey_is_found(self):
        mask = cm._subject_mask(self._image((150, 90, 60), (190, 190, 190)))
        box = cm.bbox(mask)
        self.assertIsNotNone(box)
        self.assertLess(box[0], 30)
        self.assertGreater(box[2], 30)

    def test_grey_frame_yields_empty_mask(self):
        mask = cm._subject_mask(self._image((190, 190, 190), (190, 190, 190)))
        self.assertIsNone(cm.bbox(mask))

    def test_stats_report_figure_proportions(self):
        mask = Image.new("L", (40, 80), 0)
        pixels = mask.load()
        for y in range(10, 70):
            for x in range(15, 25):
                pixels[x, y] = 255
        stats = cm.mask_stats(mask)
        self.assertEqual(stats["area"], 600)
        self.assertAlmostEqual(stats["aspect"], 6.0, delta=0.01)
        self.assertAlmostEqual(stats["fill"], 1.0, delta=0.01)


class PaletteTests(unittest.TestCase):
    def test_dominant_colour_is_reported(self):
        colours = [(200, 40, 40)] * 90 + [(20, 60, 200)] * 10
        palette = cm.dominant(colours, count=2)
        self.assertEqual(len(palette), 2)
        red, _, _ = cm.rgb_to_lab(palette[0])
        self.assertGreater(red, 30.0)

    def test_palette_distance_is_zero_for_the_same_palette(self):
        palette = cm.dominant([(200, 40, 40)] * 50)
        self.assertAlmostEqual(cm.palette_delta_e(palette, palette), 0.0, delta=1e-6)

    def test_empty_palette_is_not_a_number(self):
        self.assertNotEqual(cm.palette_delta_e([], [(1, 2, 3)]),
                            cm.palette_delta_e([], [(1, 2, 3)]))


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