class Sass::Value::Color::Space::Lab

def _convert_f_to_x_or_z(component)
  cubed = component**3
  cubed > Utils::LAB_EPSILON ? cubed : ((116 * component) - 16) / Utils::LAB_KAPPA
end

def bounded?
  false
end

def convert(dest, lightness, a, b, alpha, # rubocop:disable Naming/MethodParameterName
            missing_chroma: false, missing_hue: false)
  case dest
  when LAB
    powerless_ab = lightness.nil? || FuzzyMath.equals(lightness, 0)
    Color.send(
      :_for_space,
      dest,
      lightness,
      a.nil? || powerless_ab ? nil : a,
      b.nil? || powerless_ab ? nil : b,
      alpha
    )
  when LCH
    Utils.lab_to_lch(dest, lightness, a, b, alpha)
  else
    missing_lightness = lightness.nil?
    lightness = 0 if missing_lightness
    f1 = (lightness + 16) / 116.0
    XYZ_D50.convert(
      dest,
      _convert_f_to_x_or_z(((a.nil? ? 0 : a) / 500.0) + f1) * Conversions::D50[0],
      (if lightness > Utils::LAB_KAPPA * Utils::LAB_EPSILON
         (((lightness + 16) / 116.0)**3)
       else
         lightness / Utils::LAB_KAPPA
       end) * Conversions::D50[1],
      _convert_f_to_x_or_z(f1 - ((b.nil? ? 0 : b) / 200.0)) * Conversions::D50[2],
      alpha,
      missing_lightness:,
      missing_chroma:,
      missing_hue:,
      missing_a: a.nil?,
      missing_b: b.nil?
    )
  end
end

def initialize
  super('lab', [
    LinearChannel.new('lightness', 0, 100, lower_clamped: true, upper_clamped: true).freeze,
    LinearChannel.new('a', -125, 125).freeze,
    LinearChannel.new('b', -125, 125).freeze
  ].freeze)
end