Bmt3/128748 mobile link letter ready (#27036)

* Universal Link

- One implementation of universal link
- Think there might be a better alternative going to explore tomorrow

* Controller Move

Move the logic for selecting email template to the controller.

* Consolidate functions

One call for setting the template before send notification and send email.

* Test Coverage

Adding test coverage for the template change logic.

* Lint

- Linting autocorrect

* Adding the new setting

* Remove un-needed yaml changes

* Removed unused setting.

* Revert "Removed unused setting."

This reverts commit 0131eaa.

* Revert "Remove un-needed yaml changes"

This reverts commit ea5bf89.

* Reapply "Remove un-needed yaml changes"

This reverts commit 2a6e34e.

* Reapply "Removed unused setting."

This reverts commit b931297.

* Handle pension

* Updated old variable names.

* Simplify select email template logic.

* Refactor test changes and coverage.

* Staging template added.

* YAML file tests

* Apply suggestion from @sethdarragile6

Co-authored-by: Seth Darr <92405130+sethdarragile6@users.noreply.github.com>

* Refactor easier to follow.

* Readable version.

* Test update.

* Test coverage updates and template validaiton.

* Lint.

* Codeowners.

* Template validation moved to a constant.

* New feature flag and add actor.

* Updated templates.

* Add visibility logging.

* Move logging functions.

* Simple to follow longer function.

* Separate match function.

* Add visibility back.

* Add required templates validation logging.

* Updated tests.

* Lint.

* Template and yaml changes for vets-api specific.

* Test and controller update for feedback.

* Remove actor.

* Updating tests to include YAML tests.

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

* Test and lint updates.

* safe_load_file

* Environment to string

* Safe backup if file does not exist

* Test lint

* Remove un-needed freeze

---------

Co-authored-by: Seth Darr <92405130+sethdarragile6@users.noreply.github.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: 3 people

.github/CODEOWNERS

@@ -719,6 +719,7 @@ config/coverband.rb @department-of-veterans-affairs/backend-review-group
 config/database.yml @department-of-veterans-affairs/backend-review-group
 config/environment.rb @department-of-veterans-affairs/backend-review-group
 config/environments @department-of-veterans-affairs/backend-review-group
+config/event_bus_gateway/templates.yml @department-of-veterans-affairs/benefits-management-tools-be @department-of-veterans-affairs/backend-review-group
 config/features.yml @department-of-veterans-affairs/backend-review-group
 config/form_profile_mappings/0873.yml @department-of-veterans-affairs/vfs-virtual-agent-chatbot @department-of-veterans-affairs/backend-review-group
 config/form_profile_mappings/10-10EZR.yml @department-of-veterans-affairs/health-apps-backend @department-of-veterans-affairs/backend-review-group

app/controllers/v0/event_bus_gateway_controller.rb

@@ -4,10 +4,50 @@ module V0
   class EventBusGatewayController < SignIn::ServiceAccountApplicationController
     service_tag 'event_bus_gateway'
 
+    def self.deployment_environment
+      env = Settings.vsp_environment || Rails.env.to_s
+      %w[development test staging production].include?(env) ? env : 'blank'
+    end
+
+    def self.load_templates
+      YAML.safe_load_file(
+        Rails.root.join('config', 'event_bus_gateway', 'templates.yml')
+      )[deployment_environment]
+    rescue Errno::ENOENT, Psych::BadAlias => e
+      Rails.logger.warn("EventBusGatewayController: Failed to load templates.yml: #{e.message}")
+      {}
+    end
+
+    TEMPLATES = load_templates.freeze
+
+    REQUIRED_EMAIL_TEMPLATES = %w[
+      default_template
+      mobile_link_template
+      pension_claims_template
+      pension_mobile_link_template
+    ].freeze
+
+    def self.missing_required_templates
+      email_templates = TEMPLATES['email']
+      return REQUIRED_EMAIL_TEMPLATES.dup if email_templates.nil?
+
+      missing = []
+      REQUIRED_EMAIL_TEMPLATES.each do |template_key|
+        missing << template_key if email_templates[template_key].blank?
+      end
+      missing
+    end
+
+    def self.validate_templates
+      missing_required_templates.empty?
+    end
+
+    TEMPLATES_VALID = validate_templates.freeze
+
     def send_email
       EventBusGateway::LetterReadyEmailJob.perform_async(
         participant_id,
-        send_email_params.require(:template_id)
+        select_email_template(send_email_params.require(:template_id))
       )
       head :ok
     end
@@ -34,7 +74,7 @@ def send_notifications
 
       EventBusGateway::LetterReadyNotificationJob.perform_async(
         participant_id,
-        send_notifications_params[:email_template_id],
+        select_email_template(send_notifications_params[:email_template_id]),
         send_notifications_params[:push_template_id],
         send_notifications_params[:sms_template_id]
       )
@@ -76,5 +116,124 @@ def validate_at_least_one_template!
         }]
       }, status: :bad_request
     end
+
+    def select_email_template(original_template)
+      if original_template.blank?
+        log_blank_template
+        return original_template
+      end
+
+      unless TEMPLATES_VALID
+        log_invalid_templates
+        log_required_templates
+        return original_template
+      end
+
+      unless universal_link_enabled?
+        log_universal_link_disabled
+        return original_template
+      end
+
+      match_and_swap_template(original_template)
+    end
+
+    def match_and_swap_template(original_template)
+      case original_template
+      when TEMPLATES['email']['default_template']
+        log_default_template_matched
+        swap_to_mobile_template('mobile_link_template', 'universal link')
+      when TEMPLATES['email']['pension_claims_template']
+        log_pension_template_matched
+        swap_to_mobile_template('pension_mobile_link_template', 'pension mobile link')
+      else
+        log_no_template_matched(original_template)
+        original_template
+      end
+    end
+
+    def swap_to_mobile_template(template_key, description)
+      template_id = TEMPLATES['email'][template_key]
+
+      log_template_swap(description, template_id)
+
+      template_id
+    end
+
+    def universal_link_enabled?
+      if participant_id.blank?
+        log_blank_participant_id
+        return false
+      end
+
+      Flipper.enabled?(:event_bus_gateway_letter_ready_email_universal_link, Flipper::Actor.new(participant_id))
+    end
+
+    def log_blank_template
+      return unless Flipper.enabled?(:event_bus_gateway_controller_visibility)
+
+      Rails.logger.info('EventBusGatewayController: original_template is blank')
+    end
+
+    def log_universal_link_disabled
+      return unless Flipper.enabled?(:event_bus_gateway_controller_visibility)
+
+      Rails.logger.info('EventBusGatewayController: universal_link feature flag is disabled')
+    end
+
+    def log_blank_participant_id
+      return unless Flipper.enabled?(:event_bus_gateway_controller_visibility)
+
+      Rails.logger.info(
+        'EventBusGatewayController: participant_id is blank; universal_link feature will not be evaluated'
+      )
+    end
+
+    def log_invalid_templates
+      return unless Flipper.enabled?(:event_bus_gateway_controller_visibility)
+
+      Rails.logger.info('EventBusGatewayController: templates are invalid')
+    end
+
+    def log_default_template_matched
+      return unless Flipper.enabled?(:event_bus_gateway_controller_visibility)
+
+      Rails.logger.info('EventBusGatewayController: matched default email template')
+    end
+
+    def log_pension_template_matched
+      return unless Flipper.enabled?(:event_bus_gateway_controller_visibility)
+
+      Rails.logger.info('EventBusGatewayController: matched pension email template')
+    end
+
+    def log_no_template_matched(original_template)
+      return unless Flipper.enabled?(:event_bus_gateway_controller_visibility)
+
+      Rails.logger.info(
+        'EventBusGatewayController: no template case matched',
+        { template_id: original_template }
+      )
+    end
+
+    def log_template_swap(description, template_id)
+      return unless Flipper.enabled?(:event_bus_gateway_controller_visibility)
+
+      Rails.logger.info(
+        "EventBusGatewayController using #{description} template",
+        { swapped_template: template_id }
+      )
+    end
+
+    def log_required_templates
+      return unless Flipper.enabled?(:event_bus_gateway_controller_validation_visibility)
+
+      missing = self.class.missing_required_templates
+      return if missing.empty?
+
+      Rails.logger.info(
+        'EventBusGatewayController: missing required templates',
+        { missing_templates: missing }
+      )
+    end
   end
 end

config/event_bus_gateway/templates.yml

@@ -0,0 +1,54 @@
+development:
+  email:
+    default_template: 'dev_template123'
+    pension_claims_template: 'dev_pension_template123'
+    mobile_link_template: 'dev_mobile_link_template123'
+    pension_mobile_link_template: 'dev_pension_mobile_link_template123'
+  push:
+    default_template: 'dev_push_template123'
+  sms:
+    default_template: 'dev_sms_template123'
+
+test:
+  email:
+    default_template: 'test_template123'
+    pension_claims_template: 'test_pension_template123'
+    mobile_link_template: 'test_mobile_link_template123'
+    pension_mobile_link_template: 'test_pension_mobile_link_template123'
+  push:
+    default_template: 'test_push_template123'
+  sms:
+    default_template: 'test_sms_template123'
+
+staging:
+  email:
+    default_template: '520c5a6b-a24e-4c94-91e4-2ef50a667876'
+    pension_claims_template: '0f5f9393-225f-42f4-8773-6fe179ae0707'
+    mobile_link_template: 'f8982107-1cb2-49e6-bcd2-c4ccd9a3f443'
+    pension_mobile_link_template: '97f6e9c4-a5cc-4b97-bde8-603ed91911d7'
+  push:
+    default_template: '9B25046E39874A21BB8FD4867E6B452D'
+  sms:
+    default_template: '705ef1bf-1074-4042-aca8-bbed918c2e52'
+
+production:
+  email:
+    default_template: 'b5830306-3339-49ea-a80a-4b5105263aaf'
+    pension_claims_template: 'b600ae50-07e3-4e2e-81e5-05be8157f714'
+    mobile_link_template: ''
+    pension_mobile_link_template: ''
+  push:
+    default_template: '5D7D1E2BE5C149B0918E30F7116EC1CA'
+  sms:
+    default_template: 'be6761df-f739-4924-b86f-fddb4f501d29'
+
+blank:
+  email:
+    default_template: ''
+    pension_claims_template: ''
+    mobile_link_template: ''
+    pension_mobile_link_template: ''
+  push:
+    default_template: ''
+  sms:
+    default_template: ''

config/features.yml

@@ -229,6 +229,8 @@ features:
     description: "Gateway: Enable decision letter email notifications for EP600 predetermined notice"
   event_bus_gateway_ep930_decision_letter_notifications:
     description: "Gateway: Enable decision letter email notifications for EP930 review, referrals, and other"
+  event_bus_gateway_letter_ready_email_universal_link:
+    description: Percentage rollout flag for universal link in letter ready email notifications
   event_bus_gateway_letter_ready_push_notifications:
     description: Percentage rollout flag for push notifications in LetterReadyNotificationJob
   event_bus_gateway_letter_ready_sms_notifications:
@@ -241,6 +243,10 @@ features:
     description: "Gateway: Enable sms notifications"
   event_bus_gateway_sign_in_token_validation:
     description: Enables SignInService token validation
+  event_bus_gateway_controller_visibility:
+    description: Enables detailed logging in EventBusGatewayController for debugging and monitoring
+  event_bus_gateway_controller_validation_visibility:
+    description: System-wide flag to enable validation logging in EventBusGatewayController
   hca_browser_monitoring_enabled:
     actor_type: user
     description: Enables browser monitoring for the health care application.