mastodon/app/controllers/settings/flavours_controller.rb

# frozen_string_literal: true

class Settings::FlavoursController < Settings::BaseController

  def index
    redirect_to action: 'show', flavour: current_flavour
  end

  def show
    unless Themes.instance.flavours.include?(params[:flavour]) or params[:flavour] == current_flavour
      redirect_to action: 'show', flavour: current_flavour
    end

    @listing = Themes.instance.flavours
    @selected = params[:flavour]
  end

  def update
    user_settings.update(user_settings_params(params[:flavour]))
    redirect_to action: 'show', flavour: params[:flavour]
  end

  private

  def user_settings
    UserSettingsDecorator.new(current_user)
  end

  def user_settings_params(flavour)
    { setting_flavour: params.require(:flavour),
      setting_skin: params.dig(:user, :setting_skin)
    }.with_indifferent_access
  end
end