module InheritedResources::ClassMethods

def initialize_resources_class_accessors! #:nodoc:
  # First priority is the namespaced model, e.g. User::Group
  self.resource_class ||= begin
    namespaced_class = self.name.sub(/Controller$/, '').singularize
    namespaced_class.constantize
  rescue NameError
    nil
  end
  # Second priority is the top namespace model, e.g. EngineName::Article for EngineName::Admin::ArticlesController
  self.resource_class ||= begin
    namespaced_classes = self.name.sub(/Controller$/, '').split('::')
    namespaced_class = [namespaced_classes.first, namespaced_classes.last].join('::').singularize
    namespaced_class.constantize
  rescue NameError
    nil
  end
  # Third priority the camelcased c, i.e. UserGroup
  self.resource_class ||= begin
    camelcased_class = self.name.sub(/Controller$/, '').gsub('::', '').singularize
    camelcased_class.constantize
  rescue NameError
    nil
  end
  # Otherwise use the Group class, or fail
  self.resource_class ||= begin
    class_name = self.controller_name.classify
    class_name.constantize
  rescue NameError => e
    raise unless e.message.include?(class_name)
    nil
  end
  self.parents_symbols = self.parents_symbols.try(:dup) || []
  # Initialize resources configuration hash
  self.resources_configuration = self.resources_configuration.try(:dup) || {}
  self.resources_configuration.each do |key, value|
    next unless value.is_a?(Hash) || value.is_a?(Array)
    self.resources_configuration[key] = value.dup
  end
  config = (self.resources_configuration[:self] ||= {})
  config[:collection_name] = self.controller_name.to_sym
  config[:instance_name]   = self.controller_name.singularize.to_sym
  config[:route_collection_name] = config[:collection_name]
  config[:route_instance_name]   = config[:instance_name]
  # Deal with namespaced controllers
  namespaces = self.controller_path.split('/')[0..-2]
  # Remove namespace if its a mountable engine
  namespaces.delete_if do |namespace|
    begin
      "#{namespace}/engine".camelize.constantize.isolated?
    rescue StandardError, LoadError
      false
    end
  end
  config[:route_prefix] = namespaces.join('_').to_sym unless namespaces.empty?
  # Deal with default request parameters in namespaced controllers, e.g.
  # Forum::Thread#create will properly pick up the request parameter
  # which will be forum_thread, and not thread
  # Additionally make this work orthogonally with instance_name
  config[:request_name] = self.resource_class.to_s.underscore.tr('/', '_')
  # Initialize polymorphic, singleton, scopes and belongs_to parameters
  polymorphic = self.resources_configuration[:polymorphic] || { symbols: [], optional: false }
  polymorphic[:symbols] = polymorphic[:symbols].dup
  self.resources_configuration[:polymorphic] = polymorphic
end