tsuwatch/nazrin

require 'active_support/concern'

module Nazrin
  module Searchable
    class InvalidBatchOperationError < StandardError; end

    extend ActiveSupport::Concern

    included do
      alias_method :delete_from_index, :nazrin_delete_from_index unless method_defined? :delete_from_index
      alias_method :add_to_index, :nazrin_add_to_index unless method_defined? :add_to_index
      alias_method :update_in_index, :nazrin_update_in_index unless method_defined? :update_in_index
    end

    def nazrin_delete_from_index
      self.class.nazrin_delete_document(self)
    end

    def nazrin_add_to_index
      self.class.nazrin_add_document(self)
    end

    def nazrin_update_in_index
      self.class.nazrin_update_document(self)
    end

    module ClassMethods
      def self.extended(base)
        class << base
          alias_method :search, :nazrin_search unless method_defined? :search
          alias_method :searchable, :nazrin_searchable unless method_defined? :searchable
          alias_method :batch_operation, :nazrin_batch_operation unless method_defined? :batch_operation
          alias_method :fields, :nazrin_fields unless method_defined? :fields
          alias_method :field, :nazrin_field unless method_defined? :field
          alias_method :searchable_configure, :nazrin_searchable_configure unless method_defined? :searchable_configure
        end
      end

      def nazrin_search(options = {})
        client = Nazrin::SearchClient.new(nazrin_searchable_config)
        client.data_accessor = Nazrin::DataAccessor.for(self).new(self, options)
        client
      end

      def nazrin_searchable(&block)
        class_variable_set(
          :@@nazrin_doc_client,
          Nazrin::DocumentClient.new(nazrin_searchable_config))
        class_variable_set(:@@nazrin_search_field_data, {})
        block.call
      end

      def nazrin_batch_operation(type_objects_mapping)
        operations = type_objects_mapping.each_with_object({}) do |(type, objects), hash|
          case type.to_sym
          when :add
            hash[:add] = objects.map do |obj|
              [obj.send(:id), nazrin_eval_field_data(obj)]
            end
          when :delete
            hash[:delete] = objects.map do |obj|
              obj.send(:id)
            end
          else
            raise(
              InvalidBatchOperationError,
              "`#{type}` is not a valid batch operation"
            )
          end
        end

        nazrin_doc_client.batch(operations)
      end

      def nazrin_fields(fields)
        field_data = class_variable_get(:@@nazrin_search_field_data)
        fields.each do |field|
          field_data[field] = proc { public_send(field) }
        end
        class_variable_set(:@@nazrin_search_field_data, field_data)
      end

      def nazrin_field(field, &block)
        field_data = class_variable_get(:@@nazrin_search_field_data)
        field_data[field] = block
        class_variable_set(:@@nazrin_search_field_data, field_data)
      end

      def nazrin_doc_client
        class_variable_get(:@@nazrin_doc_client)
      end

      def nazrin_eval_field_data(obj)
        data = {}
        class_variable_get(
          :@@nazrin_search_field_data).each do |field, block|
            data[field] = obj.instance_eval(&block)
            data[field] = data[field].remove(
              /[[:cntrl:]]/) if data[field].is_a?(String)
          end
        data
      end

      def nazrin_add_document(obj)
        nazrin_doc_client.add_document(
          obj.send(:id), nazrin_eval_field_data(obj))
      end

      def nazrin_update_document(obj)
        nazrin_add_document(obj)
      end

      def nazrin_delete_document(obj)
        nazrin_doc_client.delete_document(obj.send(:id))
      end

      def nazrin_searchable_config
        @nazrin_searchable_config ||= Nazrin::Searchable::Configuration.new
      end

      def nazrin_searchable_configure
        yield nazrin_searchable_config
      end
    end
  end
end