synchronize documents generation

.rubocop.yml

@@ -31,10 +31,13 @@ Metrics/MethodLength:
     - 'db/migrate/**'
 
 Metrics/CyclomaticComplexity:
-  Max: 10
+  Max: 15
 
 Metrics/PerceivedComplexity:
-  Max: 10
+  Max: 15
+
+Layout/LineLength:
+  AllowedPatterns: ['\A\s*#']
 
 Metrics/AbcSize:
   Max: 35

app/controllers/send_submission_email_controller.rb

@@ -17,8 +17,6 @@ class SendSubmissionEmailController < ApplicationController
         Submitter.find_by!(slug: params[:submitter_slug])
       end
 
-    Submissions::GenerateResultAttachments.call(@submitter) if @submitter.documents.blank?
-
     SubmitterMailer.documents_copy_email(@submitter).deliver_later!
 
     respond_to do |f|

app/controllers/start_form_controller.rb

@@ -13,7 +13,7 @@ class StartFormController < ApplicationController
 
   def update
     @submitter = Submitter.where(submission: @template.submissions.where(deleted_at: nil))
-                          .find_or_initialize_by(**submitter_params)
+                          .find_or_initialize_by(email: submitter_params[:email])
 
     if @submitter.completed_at?
       redirect_to start_form_completed_path(@template.slug, email: submitter_params[:email])
@@ -25,7 +25,7 @@ class StartFormController < ApplicationController
         ua: request.user_agent
       )
 
-      @submitter.build_submission(template: @template)
+      @submitter.submission ||= Submission.new(template: @template)
 
       if @submitter.save
         redirect_to submit_form_path(@submitter.slug)

app/controllers/submissions_download_controller.rb

@@ -6,7 +6,7 @@ class SubmissionsDownloadController < ApplicationController
   def index
     submitter = Submitter.find_by(slug: params[:submitter_slug])
 
-    Submissions::GenerateResultAttachments.call(submitter) if submitter.documents.blank?
+    Submissions::EnsureResultGenerated.call(submitter)
 
     urls =
       Submitters.select_attachments_for_download(submitter).map do |attachment|

app/controllers/submit_form_controller.rb

@@ -24,6 +24,8 @@ class SubmitFormController < ApplicationController
     submitter.save!
 
     if submitter.completed_at?
+      GenerateSubmitterResultAttachmentsJob.perform_later(submitter)
+
       submitter.submission.template.account.users.active.each do |user|
         SubmitterMailer.completed_email(submitter, user).deliver_later!
       end

app/jobs/application_job.rb

@@ -0,0 +1,4 @@
+# frozen_string_literal: true
+
+class ApplicationJob < ActiveJob::Base
+end

app/jobs/generate_submitter_result_attachments_job.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class GenerateSubmitterResultAttachmentsJob < ApplicationJob
+  def perform(submitter)
+    Submissions::EnsureResultGenerated.call(submitter)
+  end
+end

app/mailers/submitter_mailer.rb

@@ -21,6 +21,9 @@ class SubmitterMailer < ApplicationMailer
 
   def documents_copy_email(submitter)
     @submitter = submitter
+
+    Submissions::EnsureResultGenerated.call(@submitter)
+
     @documents = Submitters.select_attachments_for_download(submitter)
 
     @documents.each do |attachment|

app/models/document_generation_event.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: document_generation_events
+#
+#  id           :bigint           not null, primary key
+#  event_name   :string           not null
+#  created_at   :datetime         not null
+#  updated_at   :datetime         not null
+#  submitter_id :bigint           not null
+#
+# Indexes
+#
+#  index_document_generation_events_on_submitter_id                 (submitter_id)
+#  index_document_generation_events_on_submitter_id_and_event_name  (submitter_id,event_name) UNIQUE WHERE ((event_name)::text = ANY ((ARRAY['start'::character varying, 'complete'::character varying])::text[]))
+#
+# Foreign Keys
+#
+#  fk_rails_...  (submitter_id => submitters.id)
+#
+class DocumentGenerationEvent < ApplicationRecord
+  belongs_to :submitter
+
+  enum :event_name, {
+    complete: 'complete',
+    fail: 'fail',
+    start: 'start',
+    retry: 'retry'
+  }, scope: false
+end

app/models/submitter.rb

@@ -39,6 +39,8 @@ class Submitter < ApplicationRecord
   has_many_attached :documents
   has_many_attached :attachments
 
+  has_many :document_generation_events, dependent: :destroy
+
   def status
     if completed_at?
       'completed'

app/views/start_form/show.html.erb

@@ -33,7 +33,7 @@
             <%= f.email_field :email, required: true, class: 'base-input', placeholder: 'Provide your email to start' %>
           </div>
           <div class="form-control">
-            <%= f.button button_title(title: 'Start'), class: 'base-button' %>
+            <%= f.button button_title(title: 'Start', disabled_with: 'Starting'), class: 'base-button' %>
           </div>
         <% end %>
       </div>

db/migrate/20230701075115_create_document_generation_events.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+class CreateDocumentGenerationEvents < ActiveRecord::Migration[7.0]
+  def change
+    create_table :document_generation_events do |t|
+      t.references :submitter, null: false, foreign_key: true, index: true
+      t.string :event_name, null: false
+
+      t.index %i[submitter_id event_name], unique: true, where: "event_name IN ('start', 'complete')"
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.0].define(version: 2023_06_12_182744) do
+ActiveRecord::Schema[7.0].define(version: 2023_07_01_075115) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -52,6 +52,15 @@ ActiveRecord::Schema[7.0].define(version: 2023_06_12_182744) do
     t.index ["blob_id", "variation_digest"], name: "index_active_storage_variant_records_uniqueness", unique: true
   end
 
+  create_table "document_generation_events", force: :cascade do |t|
+    t.bigint "submitter_id", null: false
+    t.string "event_name", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["submitter_id", "event_name"], name: "index_document_generation_events_on_submitter_id_and_event_name", unique: true, where: "((event_name)::text = ANY ((ARRAY['start'::character varying, 'complete'::character varying])::text[]))"
+    t.index ["submitter_id"], name: "index_document_generation_events_on_submitter_id"
+  end
+
   create_table "encrypted_configs", force: :cascade do |t|
     t.bigint "account_id", null: false
     t.string "key", null: false
@@ -135,6 +144,7 @@ ActiveRecord::Schema[7.0].define(version: 2023_06_12_182744) do
 
   add_foreign_key "active_storage_attachments", "active_storage_blobs", column: "blob_id"
   add_foreign_key "active_storage_variant_records", "active_storage_blobs", column: "blob_id"
+  add_foreign_key "document_generation_events", "submitters"
   add_foreign_key "encrypted_configs", "accounts"
   add_foreign_key "submissions", "templates"
   add_foreign_key "submissions", "users", column: "created_by_user_id"

lib/submissions/ensure_result_generated.rb

@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+module Submissions
+  module EnsureResultGenerated
+    WAIT_FOR_RETRY = 2.seconds
+    CHECK_EVENT_INTERVAL = 1.second
+    CHECK_COMPLETE_TIMEOUT = 20.seconds
+
+    WaitForCompleteTimeout = Class.new(StandardError)
+
+    module_function
+
+    def call(submitter)
+      return submitter.documents if submitter.document_generation_events.complete.exists?
+
+      events =
+        DocumentGenerationEvent.uncached do
+          DocumentGenerationEvent.where(submitter:).order(:created_at).to_a
+        end
+
+      if events.present? && events.last.event_name.in?(%w[start retry])
+        wait_for_complete_or_fail(submitter)
+      else
+        submitter.document_generation_events.create!(event_name: events.present? ? :retry : :start)
+
+        GenerateResultAttachments.call(submitter)
+
+        submitter.document_generation_events.create!(event_name: :complete)
+      end
+    rescue ActiveRecord::RecordNotUnique
+      sleep WAIT_FOR_RETRY
+
+      retry
+    rescue StandardError
+      submitter.document_generation_events.create!(event_name: :fail)
+
+      raise
+    end
+
+    def wait_for_complete_or_fail(submitter)
+      total_wait_time = 0
+
+      loop do
+        sleep CHECK_EVENT_INTERVAL
+        total_wait_time += CHECK_EVENT_INTERVAL
+
+        last_event =
+          DocumentGenerationEvent.uncached do
+            DocumentGenerationEvent.where(submitter:).order(:created_at).last
+          end
+
+        break last_event if last_event.event_name.in?(%w[complete fail])
+
+        raise WaitForCompleteTimeout if total_wait_time > CHECK_COMPLETE_TIMEOUT
+      end
+    end
+  end
+end

lib/submissions/generate_result_attachments.rb

@@ -209,9 +209,13 @@ module Submissions
     end
 
     def build_pdfs_index(submitter)
-      latest_submitter = submitter.submission.submitters
-                                  .select { |e| e.id != submitter.id && e.completed_at? }
-                                  .max_by(&:completed_at)
+      latest_submitter =
+        submitter.submission.submitters
+                 .select(&:completed_at?)
+                 .select { |e| e.id != submitter.id && e.completed_at <= submitter.completed_at }
+                 .max_by(&:completed_at)
+
+      Submissions::EnsureResultGenerated.call(latest_submitter) if latest_submitter
 
       documents   = latest_submitter&.documents&.preload(:blob).to_a.presence
       documents ||= submitter.submission.template.documents.preload(:blob)