module SearchMethods
  module Sfx4Solr
    module Searcher
      protected
      def find_by_title
        raise_sunspot_not_implemented_exception unless sunspot?
        _find_by_title(title_query_param, search_type_param, context_object_from_params, page)
      end
      
      def find_by_group
        raise_sunspot_not_implemented_exception unless sunspot?
        _find_by_group(_letter_group_param, context_object_from_params, page)
      end
      
      private
      # Is Umlaut configured to use Sunspot?
      def sunspot?
        begin
          Sunspot and Sunspot.const_defined?(:Rails)
        rescue
          false
        end
      end

      # Raise a NotImplementedError is Sunspot
      def raise_sunspot_not_implemented_exception
        raise NotImplementedError.new("Sunspot::Rails has not been implemented in this Umlaut instance.")
      end

      def _search_by_title(query, search_type, page=1)
        search = case search_type
          when "contains"
            az_title_klass.search {
              keywords query, :fields => [:title]
              order_by(:title_sort, :asc)
              paginate(:page => page, :per_page => 20)
            }
          when "begins"
            az_title_klass.search {
              with(:title_exact).starting_with(query)
              order_by(:title_sort, :asc)
              paginate(:page => page, :per_page => 20)
            }
          else # exact
            az_title_klass.search {
              with(:title_exact, query)
              order_by(:title_sort, :asc)
              paginate(:page => page, :per_page => 20)
            }
          end
      end
      
      def _find_by_title(query, search_type, context_object, page=1)
        search = _search_by_title(query, search_type, page)
        return [search.hits.map{|hit| _to_context_object(hit, context_object)}, search.total]
      end

      def _find_by_group(letter_group, context_object, page=1)
        search = az_title_klass.search {
          with(:letter_group, letter_group)
          order_by(:title_sort, :asc)
          paginate(:page => page, :per_page => 20)
        }
        return [search.hits.map{|hit| _to_context_object(hit, context_object)}, search.total]
      end
      
      def _to_context_object(hit, context_object)
        ctx = OpenURL::ContextObject.new
        # Start out wtih everything in search, to preserve date/vol/etc
        ctx.import_context_object(context_object)
        # Put SFX object id in rft.object_id, that's what SFX does.
        ctx.referent.set_metadata('object_id', hit.stored(:object_id) )
        ctx.referent.set_metadata("jtitle", hit.stored(:title_display) || "Unknown Title")
        ctx.referent.set_metadata("issn", hit.stored(:issn)) unless hit.stored(:issn).nil? or hit.stored(:issn).blank?
        ctx.referent.set_metadata("isbn", hit.stored(:isbn)) unless hit.stored(:isbn).nil? or hit.stored(:isbn).blank?
        ctx.referent.add_identifier("info:lccn/#{hit.stored(:lccn)}") unless hit.stored(:lccn).nil? or hit.stored(:lccn).blank?
        return ctx
      end
  
      def _letter_group_param
        case params[:id]
        when /^Other/i
          "Others"
        else
          "#{params[:id].upcase}"
        end
      end
    end
  end
end