(quality) refactored API::StatisticsController

app/controllers/api/statistics_controller.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-# API Controller for resources of type Space
+# API Controller for various statistical resources (gateway to elasticsearch DB)
 class API::StatisticsController < API::ApiController
   before_action :authenticate_user!
 
@@ -11,63 +11,42 @@ class API::StatisticsController < API::ApiController
 
   %w[account event machine project subscription training user space order].each do |path|
     class_eval %{
-      def #{path}
+      def #{path}                                                       # def account
-        authorize :statistic, :#{path}?
+        authorize :statistic, :#{path}?                                 #   authorize :statistic, :account
+        render json: Statistics::QueryService.query('#{path}', request) #   render json: Statistics::QueryService.query('account', request)
+      end                                                               # end
 
-        # remove additional parameters
+      def export_#{path}                                                # def export_account
-        statistic_type = request.query_parameters.delete('stat-type')
+        authorize :statistic, :export_#{path}?                          # authorize :statistic, :export_account?
-        custom_query = request.query_parameters.delete('custom-query')
-        start_date = request.query_parameters.delete('start-date')
-        end_date = request.query_parameters.delete('end-date')
 
-        # run main query in elasticSearch
+        @export = Statistics::QueryService.export('#{path}', params)    # @export = Statistics::QueryService.export('account', params)
-        query = MultiJson.load(request.body.read)
+        if @export.is_a?(Export)
-        results = Stats::#{path.classify}.search(query, request.query_parameters.symbolize_keys).response
-
-        # run additional custom aggregations, if any
-        CustomAggregationService.new.("#{path}", statistic_type, start_date, end_date, custom_query, results)
-
-        # return result
-        render json: results
-      end
-
-      def export_#{path}
-        authorize :statistic, :export_#{path}?
-
-        export = Export.where(category:'statistics', export_type: '#{path}', query: params[:body], key: params[:type_key]).last
-        if export.nil? || !FileTest.exist?(export.file)
-          @export = Export.new(category:'statistics',
-                               export_type: '#{path}',
-                               user: current_user,
-                               query: params[:body],
-                               key: params[:type_key])
           if @export.save
-            render json: {export_id: @export.id}, status: :ok
+            render json: { export_id: @export.id }, status: :ok
           else
             render json: @export.errors, status: :unprocessable_entity
           end
         else
-          send_file File.join(Rails.root, export.file),
+          send_file @export,
                     type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
                     disposition: 'attachment'
         end
       end
-    }, __FILE__, __LINE__ - 42
+    }, __FILE__, __LINE__ - 22
   end
 
   def export_global
     authorize :statistic, :export_global?
 
-    export = Export.where(category: 'statistics', export_type: 'global', query: params[:body]).last
+    @export = Statistics::QueryService.export(global, params)
-    if export.nil? || !FileTest.exist?(export.file)
+    if @export.is_a?(Export)
-      @export = Export.new(category: 'statistics', export_type: 'global', user: current_user, query: params[:body])
       if @export.save
         render json: { export_id: @export.id }, status: :ok
       else
         render json: @export.errors, status: :unprocessable_entity
       end
     else
-      send_file File.join(Rails.root, export.file),
+      send_file @export,
                 type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
                 disposition: 'attachment'
     end

app/services/export_service.rb

@@ -12,6 +12,8 @@ class ExportService
         last_export_reservations
       when 'users/subscription'
         last_export_subscriptions
+      when %r{statistics/.*}
+        last_export_statistics(type.split('/')[1])
       else
         raise TypeError "unknown export type: #{type}"
       end
@@ -44,5 +46,10 @@ class ExportService
             .where('created_at > ?', last_update)
             .last
     end
+
+    def last_export_statistics(type)
+      Export.where(category: 'statistics', export_type: type, query: params[:body], key: params[:type_key])
+            .last
+    end
   end
 end

app/services/statistics/query_service.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+# Query the elasticsearch database of statistics and format the result
+class Statistics::QueryService
+  class << self
+    def query(statistic_index, request)
+      # remove additional parameters
+      statistic_type = request.query_parameters.delete('stat-type')
+      custom_query = request.query_parameters.delete('custom-query')
+      start_date = request.query_parameters.delete('start-date')
+      end_date = request.query_parameters.delete('end-date')
+
+      # run main query in elasticSearch
+      query = MultiJson.load(request.body.read)
+      model = "Stats::#{statistic_index}".constantize
+      results = model.search(query, request.query_parameters.symbolize_keys).response
+
+      # run additional custom aggregations, if any
+      CustomAggregationService.new.call(statistic_index, statistic_type, start_date, end_date, custom_query, results)
+
+      results
+    end
+
+    def export(statistic_index, params)
+      export = ExportService.last_export("statistics/#{statistic_index}")
+      if export.nil? || !FileTest.exist?(export.file)
+        Export.new(category: 'statistics',
+                   export_type: statistic_index,
+                   user: current_user,
+                   query: params[:body],
+                   key: params[:type_key])
+      else
+        File.root.join(export.file)
+      end
+    end
+  end
+end