gistfile1.txt

module Queries
  class EventsFilter
    FILTER_METHOD_MAP = {
      "type"   => :filter_type,
    }

    def self.filtered_relation(filters, events)
      relation = events.includes(:mentions, :related)
      return relation unless filters.is_a?(Hash)
      filters.inject(relation) do |r, (filter, value)|
        filter_method = FILTER_METHOD_MAP[filter.to_s]
        next r unless filter_method

        send(filter_method, r, value)
      end
    end

    class << self
      private

      def filter_type(relation, type)
        type = "Events::" + type.classify
        if Event::EVENT_TYPES.include?(type)
          relation.where("events.type ILIKE ?", type)
        else
          relation.none
        end
      end
    end
  end
end