class Sass::Embedded::Host::ValueProtofier

def from_proto(proto)
  oneof = proto.value
  obj = proto.public_send(oneof)
  case oneof
  when :string
    Sass::Value::String.new(
      obj.text,
      quoted: obj.quoted
    )
  when :number
    Sass::Value::Number.new(
      obj.value, {
        numerator_units: obj.numerators.to_a,
        denominator_units: obj.denominators.to_a
      }
    )
  when :rgb_color
    Sass::Value::Color.new(
      red: obj.red,
      green: obj.green,
      blue: obj.blue,
      alpha: obj.alpha
    )
  when :hsl_color
    Sass::Value::Color.new(
      hue: obj.hue,
      saturation: obj.saturation,
      lightness: obj.lightness,
      alpha: obj.alpha
    )
  when :hwb_color
    Sass::Value::Color.new(
      hue: obj.hue,
      whiteness: obj.whiteness,
      blackness: obj.blackness,
      alpha: obj.alpha
    )
  when :argument_list
    Sass::Value::ArgumentList.new(
      obj.contents.map do |element|
        from_proto(element)
      end,
      obj.keywords.entries.to_h.transform_values! do |value|
        from_proto(value)
      end,
      ListSeparator.from_proto(obj.separator)
    ).instance_eval do
      @id = obj.id
      self
    end
  when :list
    Sass::Value::List.new(
      obj.contents.map do |element|
        from_proto(element)
      end,
      separator: ListSeparator.from_proto(obj.separator),
      bracketed: obj.has_brackets
    )
  when :map
    Sass::Value::Map.new(
      obj.entries.to_h do |entry|
        [from_proto(entry.key), from_proto(entry.value)]
      end
    )
  when :compiler_function
    Sass::Value::Function.new(obj.id)
  when :host_function
    raise Sass::ScriptError, 'The compiler may not send Value.host_function to host'
  when :singleton
    case obj
    when :TRUE
      Sass::Value::Boolean::TRUE
    when :FALSE
      Sass::Value::Boolean::FALSE
    when :NULL
      Sass::Value::Null::NULL
    else
      raise Sass::ScriptError, "Unknown Value.singleton #{obj}"
    end
  else
    raise Sass::ScriptError, "Unknown Value.value #{obj}"
  end
end

def initialize(function_registry)
  @function_registry = function_registry
end

def to_proto(obj)
  case obj
  when Sass::Value::String
    EmbeddedProtocol::Value.new(
      string: EmbeddedProtocol::Value::String.new(
        text: obj.text,
        quoted: obj.quoted?
      )
    )
  when Sass::Value::Number
    EmbeddedProtocol::Value.new(
      number: EmbeddedProtocol::Value::Number.new(
        value: obj.value.to_f,
        numerators: obj.numerator_units,
        denominators: obj.denominator_units
      )
    )
  when Sass::Value::Color
    if obj.instance_eval { !defined?(@hue) }
      EmbeddedProtocol::Value.new(
        rgb_color: EmbeddedProtocol::Value::RgbColor.new(
          red: obj.red,
          green: obj.green,
          blue: obj.blue,
          alpha: obj.alpha.to_f
        )
      )
    elsif obj.instance_eval { !defined?(@saturation) }
      EmbeddedProtocol::Value.new(
        hwb_color: EmbeddedProtocol::Value::HwbColor.new(
          hue: obj.hue.to_f,
          whiteness: obj.whiteness.to_f,
          blackness: obj.blackness.to_f,
          alpha: obj.alpha.to_f
        )
      )
    else
      EmbeddedProtocol::Value.new(
        hsl_color: EmbeddedProtocol::Value::HslColor.new(
          hue: obj.hue.to_f,
          saturation: obj.saturation.to_f,
          lightness: obj.lightness.to_f,
          alpha: obj.alpha.to_f
        )
      )
    end
  when Sass::Value::ArgumentList
    EmbeddedProtocol::Value.new(
      argument_list: EmbeddedProtocol::Value::ArgumentList.new(
        id: obj.instance_eval { @id },
        contents: obj.contents.map { |element| to_proto(element) },
        keywords: obj.keywords.transform_values { |value| to_proto(value) },
        separator: ListSeparator.to_proto(obj.separator)
      )
    )
  when Sass::Value::List
    EmbeddedProtocol::Value.new(
      list: EmbeddedProtocol::Value::List.new(
        contents: obj.contents.map { |element| to_proto(element) },
        separator: ListSeparator.to_proto(obj.separator),
        has_brackets: obj.bracketed?
      )
    )
  when Sass::Value::Map
    EmbeddedProtocol::Value.new(
      map: EmbeddedProtocol::Value::Map.new(
        entries: obj.contents.map do |key, value|
          EmbeddedProtocol::Value::Map::Entry.new(
            key: to_proto(key),
            value: to_proto(value)
          )
        end
      )
    )
  when Sass::Value::Function
    if obj.id
      EmbeddedProtocol::Value.new(
        compiler_function: EmbeddedProtocol::Value::CompilerFunction.new(
          id: obj.id
        )
      )
    else
      EmbeddedProtocol::Value.new(
        host_function: EmbeddedProtocol::Value::HostFunction.new(
          id: @function_registry.register(obj.callback),
          signature: obj.signature
        )
      )
    end
  when Sass::Value::Boolean
    EmbeddedProtocol::Value.new(
      singleton: obj.value ? :TRUE : :FALSE
    )
  when Sass::Value::Null
    EmbeddedProtocol::Value.new(
      singleton: :NULL
    )
  else
    raise Sass::ScriptError, "Unknown Sass::Value #{obj}"
  end
end