#434

backend/app/controllers/counts_exports_controller.rb

@@ -68,15 +68,15 @@ class CountsExportsController < ApplicationController
         .merge(request.query_parameters)
     exporter = CountsExporter.new(payload,
                                   language_code: locale.language_code)
-    response.headers['Content-Type'] = exporter.format == 'json' ?
-        'application/json; charset=utf-8' : 'text/csv; charset=utf-8'
-    response.headers['Content-Disposition'] =
-        "attachment; filename=\"counts-#{ exporter.resource }.#{ exporter.format }\""
-    response.headers['Cache-Control'] = 'private, no-store'
-    response.headers['X-Accel-Buffering'] = 'no'
-    # Rack::ETag otherwise materialises the response to calculate a digest.
-    response.headers['Last-Modified'] = Time.current.httpdate
-    self.response_body = exporter.body
+    session[:counts_export_owner] ||= SecureRandom.hex(32)
+    token = CountsExportDownload.prepare(exporter, session[:counts_export_owner])
+    file = CountsExportDownload.find(token, session[:counts_export_owner])
+    return head :not_found unless file
+
+    send_file file.fetch('path'),
+        filename: "counts-#{ exporter.resource }.#{ exporter.format }",
+        type: exporter.format == 'json' ? 'application/json' : 'text/csv',
+        disposition: 'attachment'
   rescue ArgumentError, TypeError, KeyError, JSON::ParserError
     head :bad_request
   end