devise_for :users, path: '',
  path_names: {
    sign_up: '',
    registration: 'signup',
    sign_in: 'login',
    password: 'password',
    confirmation: 'verification'
  },
  controllers: {
    sessions: 'users/sessions',
    registrations: 'users/registrations',
    omniauth_callbacks: 'users/omniauth_callbacks',
    passwords: 'users/passwords'
  }

resources :users, path: '', only: [:show] do
  member do
    get 'reviews', to: 'users#reviews', as: :reviews
    get :following, :followers
    post :follow, to: 'users#follow_user'
    post :unfollow, to: 'users#unfollow_user'
  end
end

resources :companies, path: '', only: [:show], as: :company do
  resources :products, path: '', only: [:show], as: :product
end

module Constraints
  class UserProfile
    def matches?(request)
      if request.path.include?('@')
        slug = request.path.delete('/@')
        User.where(slug: slug).exists?
      end
    end
  end
end

def set_user
  @user = User.includes(:reviews).find(params[:id].delete('@'))
end

# overwrite normalize function because it's stripping
# out '@' when calling .parameterize
def normalize_friendly_id(value)
  "@" + value.to_s.parameterize
end

User.each do |u|
  u.update_attribute(:slug, nil)
end

User.find_each(&:save)

constraints(Constraints::UserProfile.new) do
  resources :users,
  ....
end

module Constraints
  class UserProfile
    def matches?(request)
      if request.path.match? //@(.*)/
        slug = request.path.split('/')[1]
        User.where(slug: slug).exists?
      end
    end
  end
end