Enhance payment processing, add performance profiling, and improve code quality

Gemfile

@@ -17,6 +17,8 @@ gem 'redis', '>= 4.0.1'
 gem 'sassc-rails'
 gem "sentry-ruby"
 gem "sentry-rails"
+# Required when Sentry profiles_sample_rate is set (see config/initializers/sentry.rb)
+gem 'stackprof'
 gem 'skylight'
 gem 'stimulus-rails'
 gem 'turbo-rails'
@@ -40,6 +42,8 @@ group :development, :test do
   gem 'pry-rails'
   gem 'rails-controller-testing'
   gem 'rspec-rails'
+  gem "rubocop", "~> 1.86"
+  gem "rubocop-rails"
   gem 'simplecov'
   gem 'webdrivers'
 end

Gemfile.lock

@@ -92,6 +92,7 @@ GEM
     arbre (1.7.0)
       activesupport (>= 3.0.0)
       ruby2_keywords (>= 0.0.2)
+    ast (2.4.3)
     base64 (0.3.0)
     bcrypt (3.1.22)
     benchmark (0.5.0)
@@ -187,6 +188,7 @@ GEM
       thor (>= 0.14, < 2.0)
     jsbundling-rails (1.3.1)
       railties (>= 6.0.0)
+    json (2.19.3)
     kaminari (1.2.2)
       activesupport (>= 4.1.0)
       kaminari-actionview (= 1.2.2)
@@ -199,6 +201,7 @@ GEM
       activerecord
       kaminari-core (= 1.2.2)
     kaminari-core (1.2.2)
+    language_server-protocol (3.17.0.5)
     launchy (3.1.1)
       addressable (~> 2.8)
       childprocess (~> 5.0)
@@ -210,6 +213,7 @@ GEM
       letter_opener (~> 1.9)
       railties (>= 6.1)
       rexml
+    lint_roller (1.1.0)
     logger (1.7.0)
     loofah (2.25.1)
       crass (~> 1.0.2)
@@ -251,10 +255,15 @@ GEM
       racc (~> 1.4)
     orm_adapter (0.5.0)
     ostruct (0.6.3)
+    parallel (1.28.0)
+    parser (3.3.11.1)
+      ast (~> 2.4.1)
+      racc
     pg (1.5.9)
     pp (0.6.2)
       prettyprint
     prettyprint (0.2.0)
+    prism (1.9.0)
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
@@ -313,6 +322,7 @@ GEM
       thor (~> 1.0, >= 1.2.2)
       tsort (>= 0.2)
       zeitwerk (~> 2.6)
+    rainbow (3.1.1)
     rake (13.2.1)
     ransack (4.4.1)
       activerecord (>= 7.2)
@@ -349,6 +359,27 @@ GEM
       rspec-mocks (~> 3.13)
       rspec-support (~> 3.13)
     rspec-support (3.13.2)
+    rubocop (1.86.0)
+      json (~> 2.3)
+      language_server-protocol (~> 3.17.0.2)
+      lint_roller (~> 1.1.0)
+      parallel (~> 1.10)
+      parser (>= 3.3.0.2)
+      rainbow (>= 2.2.2, < 4.0)
+      regexp_parser (>= 2.9.3, < 3.0)
+      rubocop-ast (>= 1.49.0, < 2.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (>= 2.4.0, < 4.0)
+    rubocop-ast (1.49.1)
+      parser (>= 3.3.7.2)
+      prism (~> 1.7)
+    rubocop-rails (2.34.3)
+      activesupport (>= 4.2.0)
+      lint_roller (~> 1.1)
+      rack (>= 1.1)
+      rubocop (>= 1.75.0, < 2.0)
+      rubocop-ast (>= 1.44.0, < 2.0)
+    ruby-progressbar (1.13.0)
     ruby2_keywords (0.0.5)
     rubyzip (2.4.1)
     sassc (2.4.0)
@@ -385,6 +416,7 @@ GEM
       actionpack (>= 6.1)
       activesupport (>= 6.1)
       sprockets (>= 3.0.0)
+    stackprof (0.2.28)
     stimulus-rails (1.3.4)
       railties (>= 6.0.0)
     stringio (3.1.5)
@@ -398,6 +430,9 @@ GEM
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
     unaccent (0.4.0)
+    unicode-display_width (3.2.0)
+      unicode-emoji (~> 4.1)
+    unicode-emoji (4.2.0)
     useragent (0.16.11)
     warden (1.2.9)
       rack (>= 2.0.9)
@@ -452,11 +487,14 @@ DEPENDENCIES
   rails-controller-testing
   redis (>= 4.0.1)
   rspec-rails
+  rubocop (~> 1.86)
+  rubocop-rails
   sassc-rails
   sentry-rails
   sentry-ruby
   simplecov
   skylight
+  stackprof
   stimulus-rails
   turbo-rails
   tzinfo-data

app/admin/dashboard.rb

@@ -36,7 +36,8 @@
       column do
         current_year_applications_scope = Application.active_conference_applications
         current_year_application_count = current_year_applications_scope.count
-        recent_applications = current_year_applications_scope.order(created_at: :desc).limit(25)
+        recent_applications =
+          current_year_applications_scope.order(created_at: :desc).limit(25)
 
         panel "Latest 25 of #{current_year_application_count} Applications for the #{ApplicationSetting.get_current_app_year} conference" do
           table_for recent_applications do
@@ -69,10 +70,28 @@
 
       column do
         panel "Recent Payments" do
-          table_for Payment.current_conference_payments.sort.reverse.first(10) do
+          recent_payments =
+            Payment.current_conference_payments
+                   .order(created_at: :desc)
+                   .limit(10)
+                   .includes(:user)
+                   .to_a
+          conf_year = ApplicationSetting.get_current_app_year
+          user_ids = recent_payments.map(&:user_id).uniq
+          current_app_by_user_id =
+            if user_ids.empty?
+              {}
+            else
+              Application.where(user_id: user_ids, conf_year: conf_year)
+                         .order(:user_id, :id)
+                         .group_by(&:user_id)
+                         .transform_values(&:last)
+            end
+          table_for recent_payments do
             column("Name") do |a|
-              if a.user.current_conf_application.present?
-                link_to a.user.current_conf_application.display_name, admin_application_path(a.user.current_conf_application)
+              app = current_app_by_user_id[a.user_id]
+              if app.present?
+                link_to app.display_name, admin_application_path(app)
               else
                 "#{a.user.email} ( - waiting for application to be submitted)"
               end
@@ -128,7 +147,7 @@
           panel "Waiting for responses from these #{ApplicationSetting.get_current_app_year} applicants (#{offered_count})" do
             applications =
               if offered_applications.respond_to?(:sort)
-                offered_applications.sort.reverse
+                offered_applications.includes(:user).sort.reverse
               else
                 Array(offered_applications).select { |app| app.respond_to?(:user) }
               end

app/admin/payment_gateway_callbacks.rb

@@ -0,0 +1,55 @@
+ActiveAdmin.register PaymentGatewayCallback do
+  menu parent: 'User Management', priority: 2.5, label: 'Gateway callbacks'
+
+  actions :index, :show
+
+  config.sort_order = 'created_at_desc'
+
+  filter :transaction_id
+  filter :processing_status, as: :select, collection: PaymentGatewayCallback::PROCESSING_STATUSES
+  filter :event_type
+  filter :user
+  filter :payment
+  filter :created_at
+
+  index do
+    actions
+    column :id do |callback|
+      link_to callback.id, admin_payment_gateway_callback_path(callback)
+    end
+    column :transaction_id
+    column :processing_status
+    column :event_type
+    column :user
+    column :payment
+    column :failure_reason do |callback|
+      truncate(callback.failure_reason.to_s, length: 80)
+    end
+    column :created_at
+  end
+
+  show do
+    attributes_table do
+      row :id
+      row :transaction_id
+      row :processing_status
+      row :event_type
+      row :user do |callback|
+        if callback.user
+          link_to(callback.user.email, admin_user_path(callback.user))
+        end
+      end
+      row :payment do |callback|
+        if callback.payment
+          link_to("Payment ##{callback.payment.id}", admin_payment_path(callback.payment))
+        end
+      end
+      row :failure_reason
+      row :created_at
+      row :updated_at
+      row :payload do |callback|
+        pre JSON.pretty_generate(callback.payload.presence || {})
+      end
+    end
+  end
+end

app/admin/payments.rb

@@ -75,6 +75,26 @@
       row :created_at
       row :updated_at
     end
+
+    panel 'Gateway callbacks' do
+      callbacks = payment.payment_gateway_callbacks.order(created_at: :desc)
+      if callbacks.any?
+        table_for callbacks do
+          column :id do |callback|
+            link_to(callback.id, admin_payment_gateway_callback_path(callback))
+          end
+          column :processing_status
+          column :transaction_id
+          column :failure_reason do |callback|
+            truncate(callback.failure_reason.to_s, length: 60)
+          end
+          column :created_at
+        end
+      else
+        para 'No gateway callback rows are linked to this payment. Callbacks are attached when a gateway receipt is successfully recorded for this row.'
+      end
+    end
+
     active_admin_comments
   end