Add submission batch service

This service takes a set of submissions, retrieves a set of CSVs for
them grouped by form version, and initiates a batch submission
mail delivery.

Co-authored-by: Stephen Daly <stephen.daly@digital.cabinet-office.gov.uk>

Author: SamJamCul

app/services/aws_ses_submission_batch_service.rb

@@ -0,0 +1,39 @@
+class AwsSesSubmissionBatchService
+  def initialize(submissions:, form:, date:, mode:)
+    @submissions = submissions
+    @form = form
+    @date = date
+    @mode = mode
+  end
+
+  def send_batch
+    if @form.submission_email.blank?
+      if @mode.preview?
+        Rails.logger.info "Skipping sending batch for preview submissions, as the submission email address has not been set"
+        return
+      else
+        raise StandardError, "Form id: #{@form.id} is missing a submission email address"
+      end
+    end
+
+    deliver_batch_email
+  end
+
+private
+
+  def deliver_batch_email
+    files = {}
+
+    submissions_by_version = Submission.group_by_form_version(@submissions)
+    submissions_by_version.each_value.with_index(1) do |submissions, version_number|
+      form_version = submissions_by_version.size > 1 ? version_number : nil
+      filename = SubmissionFilenameGenerator.batch_csv_filename(form_name: @form.name, date: @date, mode: @mode, form_version: form_version)
+      files[filename] = CsvGenerator.generate_batched_submissions(submissions: submissions, is_s3_submission: false)
+    end
+
+    mail = AwsSesSubmissionBatchMailer.batch_submission_email(form: @form, date: @date, mode: @mode, files:).deliver_now
+
+    CurrentJobLoggingAttributes.delivery_reference = mail.message_id
+    mail.message_id
+  end
+end

spec/factories/v2_form_document.rb

@@ -24,6 +24,7 @@
     s3_bucket_aws_account_id { nil }
     s3_bucket_name { nil }
     s3_bucket_region { nil }
+    updated_at { Time.current.iso8601(3) }
 
     trait :with_steps do
       transient do
@@ -35,6 +36,7 @@
       end
 
       question_section_completed { true }
+      start_page { steps.first[:id] }
     end
 
     trait :with_privacy_policy_url do

spec/services/aws_ses_submission_batch_service_spec.rb

@@ -0,0 +1,81 @@
+require "rails_helper"
+
+RSpec.describe AwsSesSubmissionBatchService do
+  let(:service) { described_class.new(submissions:, form:, date:, mode:) }
+  let(:form) { build(:form, id: form_latest_version.form_id, submission_email:) }
+  let(:form_earlier_version) { create(:v2_form_document, :with_steps, form_id: form_latest_version.form_id, updated_at: form_earlier_version_updated_at) }
+  let(:form_latest_version) { create(:v2_form_document, :with_steps, updated_at: form_latest_version_updated_at) }
+  let(:submission_email) { "submit@email.gov.uk" }
+  let(:form_earlier_version_updated_at) { Time.utc(2022, 9, 14, 7, 0, 0).iso8601(3) }
+  let(:form_latest_version_updated_at) { Time.utc(2022, 9, 14, 8, 0, 0).iso8601(3) }
+  let(:date) { Date.new(2024, 6, 1) }
+  let(:mode) { instance_double(Mode, preview?: false) }
+  let(:submissions) { earlier_version_submissions + latest_version_submissions }
+  let(:earlier_version_submissions) { create_list(:submission, 2, form_document: form_earlier_version) }
+  let(:latest_version_submissions) { create_list(:submission, 3, form_document: form_latest_version) }
+
+  describe "#send_batch" do
+    before do
+      allow(SubmissionFilenameGenerator).to receive(:batch_csv_filename).and_return("filename.csv", "filename-2.csv")
+      allow(CsvGenerator).to receive(:generate_batched_submissions).and_return("csv-content", "csv-content-2")
+    end
+
+    context "when the form does not have a submission email address" do
+      let(:submission_email) { nil }
+
+      it "raises an error" do
+        expect(AwsSesSubmissionBatchMailer).not_to receive(:batch_submission_email)
+        expect { service.send_batch }.to raise_error(StandardError, "Form id: #{form.id} is missing a submission email address")
+      end
+
+      context "when the mode is preview" do
+        let(:mode) { instance_double(Mode, preview?: true) }
+
+        it "does not send an email" do
+          expect(AwsSesSubmissionBatchMailer).not_to receive(:batch_submission_email)
+          service.send_batch
+        end
+      end
+    end
+
+    it "calls the SubmissionFilenameGenerator to generate a filename for each form version" do
+      expect(SubmissionFilenameGenerator).to receive(:batch_csv_filename).with(form_name: form.name, date:, mode:, form_version: 1)
+      expect(SubmissionFilenameGenerator).to receive(:batch_csv_filename).with(form_name: form.name, date:, mode:, form_version: 2)
+      service.send_batch
+    end
+
+    context "when there is only one form version" do
+      let(:submissions) { latest_version_submissions }
+
+      it "calls the SubmissionFilenameGenerator with a nil form version" do
+        expect(SubmissionFilenameGenerator).to receive(:batch_csv_filename).with(form_name: form.name, date:, mode:, form_version: nil)
+        service.send_batch
+      end
+    end
+
+    it "calls the CsvGenerator for each form version" do
+      expect(CsvGenerator).to receive(:generate_batched_submissions).with(submissions: earlier_version_submissions, is_s3_submission: false)
+      expect(CsvGenerator).to receive(:generate_batched_submissions).with(submissions: latest_version_submissions, is_s3_submission: false)
+      service.send_batch
+    end
+
+    it "calls the AwsSesSubmissionBatchMailer to send the email with the generated files" do
+      expect(AwsSesSubmissionBatchMailer).to receive(:batch_submission_email)
+        .with(
+          form:,
+          date:,
+          mode:,
+          files: { "filename.csv" => "csv-content", "filename-2.csv" => "csv-content-2" },
+        ).and_call_original
+
+      service.send_batch
+    end
+
+    it "returns the message id" do
+      message_id = service.send_batch
+
+      last_email = ActionMailer::Base.deliveries.last
+      expect(message_id).to eq last_email.message_id
+    end
+  end
+end