From 1cfd3250c0a94cf5001b0e09cf9232b7172696c8 Mon Sep 17 00:00:00 2001
From: Karina Kwiatek <kjk@kjk.dog>
Date: Tue, 27 Dec 2022 23:22:51 +0000
Subject: [PATCH] Track failures on Web Push subscriptions

---
 .../settings/push_notifications_controller.rb          |  2 +-
 app/models/user/push_notification_methods.rb           |  2 +-
 app/models/web_push_subscription.rb                    |  3 +++
 config/initializers/rpush.rb                           | 10 ++++++++--
 ...226101907_add_failures_to_web_push_subscriptions.rb |  7 +++++++
 db/schema.rb                                           |  1 +
 6 files changed, 21 insertions(+), 4 deletions(-)
 create mode 100644 db/migrate/20221226101907_add_failures_to_web_push_subscriptions.rb

diff --git a/app/controllers/settings/push_notifications_controller.rb b/app/controllers/settings/push_notifications_controller.rb
index 551ae46e..f207cb32 100644
--- a/app/controllers/settings/push_notifications_controller.rb
+++ b/app/controllers/settings/push_notifications_controller.rb
@@ -4,6 +4,6 @@ class Settings::PushNotificationsController < ApplicationController
   before_action :authenticate_user!
 
   def index
-    @subscriptions = current_user.web_push_subscriptions
+    @subscriptions = current_user.web_push_subscriptions.active
   end
 end
diff --git a/app/models/user/push_notification_methods.rb b/app/models/user/push_notification_methods.rb
index f2446805..01138633 100644
--- a/app/models/user/push_notification_methods.rb
+++ b/app/models/user/push_notification_methods.rb
@@ -4,7 +4,7 @@ module User::PushNotificationMethods
   def push_notification(app, resource)
     raise ArgumentError("Resource must respond to `as_push_notification`") unless resource.respond_to? :as_push_notification
 
-    web_push_subscriptions.each do |s|
+    web_push_subscriptions.active.find_each do |s|
       n = Rpush::Webpush::Notification.new
       n.app = app
       n.registration_ids = [s.subscription.symbolize_keys]
diff --git a/app/models/web_push_subscription.rb b/app/models/web_push_subscription.rb
index dddf28db..6821d10b 100644
--- a/app/models/web_push_subscription.rb
+++ b/app/models/web_push_subscription.rb
@@ -2,4 +2,7 @@
 
 class WebPushSubscription < ApplicationRecord
   belongs_to :user
+
+  scope :active, -> { where(failures: ...3) }
+  scope :failed, -> { where(failures: 3..) }
 end
diff --git a/config/initializers/rpush.rb b/config/initializers/rpush.rb
index 0aaf129c..3cb8eb77 100644
--- a/config/initializers/rpush.rb
+++ b/config/initializers/rpush.rb
@@ -57,8 +57,14 @@ Rpush.reflect do |on|
 
   # Called when notification delivery failed.
   # Call 'error_code' and 'error_description' on the notification for the cause.
-  # on.notification_failed do |notification|
-  # end
+  on.notification_failed do |notification|
+    # See: https://developer.apple.com/documentation/usernotifications/sending_web_push_notifications_in_safari_and_other_browsers#3994594
+    if %i[403 410].include? notification.error_code
+      subscription = WebPushSubscription::where("subscription ->> 'endpoint' = ?", notification.registration_ids.first[:endpoint])
+      subscription.increment :failures
+      subscription.save
+    end
+  end
 
   # Called when the notification delivery failed and only the notification ID
   # is present in memory.
diff --git a/db/migrate/20221226101907_add_failures_to_web_push_subscriptions.rb b/db/migrate/20221226101907_add_failures_to_web_push_subscriptions.rb
new file mode 100644
index 00000000..e52b50e7
--- /dev/null
+++ b/db/migrate/20221226101907_add_failures_to_web_push_subscriptions.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddFailuresToWebPushSubscriptions < ActiveRecord::Migration[6.1]
+  def change
+    add_column :web_push_subscriptions, :failures, :integer, default: 0
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 6c2491d6..05514255 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -387,6 +387,7 @@ ActiveRecord::Schema.define(version: 2022_12_27_065923) do
     t.json "subscription"
     t.datetime "created_at", precision: 6, null: false
     t.datetime "updated_at", precision: 6, null: false
+    t.integer "failures", default: 0
     t.index ["user_id"], name: "index_web_push_subscriptions_on_user_id"
   end