#434

backend/app/services/counts_exporter.rb

@@ -47,14 +47,17 @@ class CountsExporter
     end
   end
 
-  def body
-    return @table_export.body if @table_export
+  def body(progress: nil)
+    return @table_export.body(progress:) if @table_export
 
     Enumerator.new do |output|
       ApplicationRecord.transaction(isolation: :repeatable_read) do
+        processed = 0
         first_row = true
         started = false
         pages do |page|
+          total = @mode == 'details' ? page[:count] : nil
+          progress&.call(processed, total)
           unless started
             meta = { resource:, mode: @mode, basis: @history ? 'history' : 'state',
                      at: @query_params['at'], boundary: 'inclusive',
@@ -83,8 +86,11 @@ class CountsExporter
               output << CSV.generate_line(values, row_sep: "\r\n")
             end
             first_row = false
+            processed += 1
+            progress&.call(processed, total)
           end
         end
+        progress&.call(processed, processed)
         output << ']}' if format == 'json'
       end
     end