module Arrest
  class RestChild < AbstractResource
    attr_accessor :parent
    def initialize context, parent, h
      super(context,h)
      @parent = parent
    end

    class << self
      # class method to generate path to a child resource of aonther resource
      def resource_path_for parent
        "#{parent.resource_location}/#{self.resource_name}"
      end

      def scoped_path_for parent, scope_name
        (resource_path_for parent) + '/' + scope_name.to_s
      end

      def build(parent, hash)
        self.new(parent.context, parent, hash)
      end

      def all_for(parent)
        raise "Parent has no id yet" unless parent.id
        begin
          body_root(source().get_many(parent.context, self.resource_path_for(parent))).map do |h|
            self.build(parent, h)
          end
        rescue Arrest::Errors::DocumentNotFoundError
          []
        end
      end

      def find(context, id)
        raise "find cannot be executed for child resources - use find_for with a parent"
      end

      def find_for(context, parent, id)
        r = source().get_one(context, "#{self.resource_path_for(parent)}/#{id}")
        body = body_root(r)
        self.build(parent, body)
      end

      def filter name, &aproc
        if aproc != nil
          send :define_singleton_method, name do |*args|
            self.all_for(args[0]).select do |instance|
              instance.instance_exec(*(args.drop(1)), &aproc)
            end
          end
        else
          raise "You must specify a block for a filter"
        end
      end

      def scope(name, &block)
        super name
        if block_given?
          send :define_singleton_method, name do |parent|
            self.all_for(parent).select &block
          end
        else
          send :define_singleton_method, name do |parent|
            raise "Parent has no id yet" unless parent.id
            body_root(source().get_many(parent.context, self.scoped_path_for(parent, name))).map do |h|
              self.build(parent, h)
            end
          end
        end

      end
    end

    # instance method to generate path to a child resource of another resource
    def resource_path
      self.class.resource_path_for @parent
    end

    # unique url for one instance of this class
    def resource_location
      "#{self.class.resource_path}/#{self.id.to_s}"
    end

    def unstub
      return unless @stub
      raise "stubbing for child resource isnt supported yet"
    end

    protected
    def internal_reload
      @parent.reload
      self.class.find_for(self.context, self.parent, self.id).to_hash
    end
  end
end