import pathlib
import tempfile
import unittest
import unittest.mock

import generator.theme

class ThemeTests(unittest.TestCase):
  def test_foregrounds_remain_readable_on_dark_surfaces(self):
    def luminance(color):
      channels = [value / 255 for value in color]
      linear = [value / 12.92 if value <= 0.04045 else ((value + 0.055) / 1.055) ** 2.4 for value in channels]
      return sum(value * weight for value, weight in zip(linear, (0.2126, 0.7152, 0.0722)))
    for surface in ('background', 'panel', 'selection'):
      background = luminance(generator.theme.rgb(surface))
      self.assertLess(background, 0.06)
      for name in ('ink', 'muted', 'accent', 'connecting', 'retrying', 'connected', 'danger'):
        contrast = (luminance(generator.theme.rgb(name)) + 0.05) / (background + 0.05)
        self.assertGreaterEqual(contrast, 4.5, (name, surface))
  def test_cpp_colors_match_the_renderer_palette_without_rewriting(self):
    with tempfile.TemporaryDirectory() as temporary:
      header = pathlib.Path(temporary) / 'palette.hpp'
      generator.theme.generate_header(header)
      stamp = header.stat().st_mtime_ns
      for name in generator.theme.COLORS:
        red, green, blue = generator.theme.rgb(name)
        self.assertIn(f'{name} = vamp_style::color{{{red}, {green}, {blue}, 255}};', header.read_text())
      generator.theme.generate_header(header)
      self.assertEqual(stamp, header.stat().st_mtime_ns)
  def test_invalid_colors_fail_before_writing(self):
    with unittest.mock.patch.dict(generator.theme.COLORS, {'background': '#xyz'}):
      with self.assertRaisesRegex(ValueError, 'background'):
        generator.theme.rgb('background')