module ActionDispatch::Routing::Mapper::Resources

def arvm_resource(resource_name, options = {}, &block)
  except             = options.delete(:except) { [] }
  add_shallow_routes = options.delete(:add_shallow_routes) { true }
  defaults           = options.delete(:defaults) { {} }
  only_routes = []
  nested = shallow_nesting_depth > 0
  association_name = options.delete(:association_name) { resource_name.to_s }
  owner_viewmodel  = options.delete(:owner_viewmodel) do
    if nested
      parent_resource.name.to_s.singularize.camelize
    end
  end
  defaults = {
    association_name: association_name,
    owner_viewmodel: owner_viewmodel,
  }.merge(defaults)
  if nested && !except.include?(:create_associated_bulk)
    collection do
      post resource_name, controller: resource_name, action: :create_associated_bulk, as: nil, defaults: defaults
    end
  end
  resource resource_name, shallow: true, only: only_routes, defaults: defaults, **options do
    instance_eval(&block) if block_given?
    name_route = { as: '' } # Only one route may take the name
    if nested
      post('',   action: :create_associated,  **name_route.extract!(:as)) unless except.include?(:create)
      get('',    action: :show_associated,    **name_route.extract!(:as)) unless except.include?(:show)
      delete('', action: :destroy_associated, **name_route.extract!(:as)) unless except.include?(:destroy)
    else
      post('',   action: :create,  **name_route.extract!(:as)) unless except.include?(:create)
      get('',    action: :show,    **name_route.extract!(:as)) unless except.include?(:show)
      delete('', action: :destroy, **name_route.extract!(:as)) unless except.include?(:destroy)
    end
  end
  # singularly nested resources provide collection accessors at the top level
  if nested && add_shallow_routes
    resources resource_name.to_s.pluralize, shallow: true, only: [:show, :destroy] - except do
      shallow_scope do
        collection do
          name_route = { as: '' } # Only one route may take the name
          post('', action: :create, **name_route.extract!(:as)) unless except.include?(:create)
          get('',  action: :index,  **name_route.extract!(:as)) unless except.include?(:index)
        end
      end
    end
  end
end

def arvm_resources(resource_name, options = {}, &block)
  except             = options.delete(:except) { [] }
  add_shallow_routes = options.delete(:add_shallow_routes) { true }
  defaults           = options.delete(:defaults) { {} }
  nested = shallow_nesting_depth > 0
  association_name = options.delete(:association_name) { resource_name.to_s }
  owner_viewmodel  = options.delete(:owner_viewmodel) do
    if nested
      parent_resource.name.to_s.singularize.camelize
    end
  end
  defaults = {
    association_name: association_name,
    owner_viewmodel: owner_viewmodel,
  }.merge(defaults)
  only_routes = []
  only_routes += [:create] unless nested
  only_routes += [:show, :destroy] if add_shallow_routes
  only_routes -= except
  # Bulk replace
  if nested && !except.include?(:replace_bulk)
    collection do
      post resource_name, controller: resource_name, action: :replace_bulk, as: nil, defaults: defaults
    end
  end
  resources resource_name, shallow: true, only: only_routes, defaults: defaults, **options do
    instance_eval(&block) if block_given?
    if nested
      # Nested controllers also get :append and :disassociate, and alias a top level create.
      collection do
        name_route = { as: '' } # Only one route may take the name
        get('',    action: :index_associated, **name_route.extract!(:as)) unless except.include?(:index)
        put('',    action: :append,           **name_route.extract!(:as)) unless except.include?(:append)
        post('',   action: :replace,          **name_route.extract!(:as)) unless except.include?(:replace)
        delete('', action: :disassociate_all, **name_route.extract!(:as)) unless except.include?(:disassociate_all)
      end
      scope shallow: false do
        member do
          delete '', action: :disassociate, as: '' unless except.include?(:disassociate)
        end
      end
      # Add top level `create` route to manipulate existing viewmodels
      # without providing parent context
      shallow_scope do
        collection do
          name_route = { as: '' } # Only one route may take the name
          post('', action: :create, **name_route.extract!(:as)) unless except.include?(:create) || !add_shallow_routes
          get('',  action: :index,  **name_route.extract!(:as)) unless except.include?(:index)  || !add_shallow_routes
          delete('', action: :destroy, as: :bulk_delete) unless except.include?(:destroy) || !add_shallow_routes
        end
      end
    else
      collection do
        get('', action: :index, as: '') unless except.include?(:index)
        delete('', action: :destroy, as: :bulk_delete) unless except.include?(:destroy)
      end
    end
  end
end