Web Push Notifications (#3243)

* feat: Register push subscription

* feat: Notify when mentioned

* feat: Boost, favourite, reply, follow, follow request

* feat: Notification interaction

* feat: Handle change of public key

* feat: Unsubscribe if things go wrong

* feat: Do not send normal notifications if push is enabled

* feat: Focus client if open

* refactor: Move push logic to WebPushSubscription

* feat: Better title and body

* feat: Localize messages

* chore: Fix lint errors

* feat: Settings

* refactor: Lazy load

* fix: Check if push settings exist

* feat: Device-based preferences

* refactor: Simplify logic

* refactor: Pull request feedback

* refactor: Pull request feedback

* refactor: Create /api/web/push_subscriptions endpoint

* feat: Spec PushSubscriptionController

* refactor: WebPushSubscription => Web::PushSubscription

* feat: Spec Web::PushSubscription

* feat: Display first media attachment

* feat: Support direction

* fix: Stuff broken while rebasing

* refactor: Integration with session activations

* refactor: Cleanup

* refactor: Simplify implementation

* feat: Set VAPID keys via environment

* chore: Comments

* fix: Crash when no alerts

* fix: Set VAPID keys in testing environment

* fix: Follow link

* feat: Notification actions

* fix: Delete previous subscription

* chore: Temporary logs

* refactor: Move migration to a later date

* fix: Fetch the correct session activation and misc bugs

* refactor: Move migration to a later date

* fix: Remove follow request (no notifications)

* feat: Send administrator contact to push service

* feat: Set time-to-live

* fix: Do not show sensitive images

* fix: Reducer crash in error handling

* feat: Add badge

* chore: Fix lint error

* fix: Checkbox label overlap

* fix: Check for payload support

* fix: Rename action "type" (crash in latest Chrome)

* feat: Action to expand notification

* fix: Lint errors

* fix: Unescape notification body

* fix: Do not allow boosting if the status is hidden

* feat: Add VAPID keys to the production sample environment

* fix: Strip HTML tags from status

* refactor: Better error messages

* refactor: Handle browser not implementing the VAPID protocol (Samsung Internet)

* fix: Error when target_status is nil

* fix: Handle lack of image

* fix: Delete reference to invalid subscriptions

* feat: Better error handling

* fix: Unescape HTML characters after tags are striped

* refactor: Simpify code

* fix: Modify to work with #4091

* Sort strings alphabetically

* i18n: Updated Polish translation

it annoys me that it's not fully localized :P

* refactor: Use current_session in PushSubscriptionController

* fix: Rebase mistake

* fix: Set cacheName to mastodon

* refactor: Pull request feedback

* refactor: Remove logging statements

* chore(yarn): Fix conflicts with master

* chore(yarn): Copy latest from master

* chore(yarn): Readd offline-plugin

* refactor: Use save! and update!

* refactor: Send notifications async

* fix: Allow retry when push fails

* fix: Save track for failed pushes

* fix: Minify sw.js

* fix: Remove account_id from fabricator

3 files changed, 206 insertions, 0 deletions

diff --git a/app/models/session_activation.rb b/app/models/session_activation.rb
index 887e3e3bd..7eb16af8f 100644
--- a/app/models/session_activation.rb
+++ b/app/models/session_activation.rb
@@ -3,6 +3,17 @@
 #
 # Table name: session_activations
 #
+#  id                       :integer          not null, primary key
+#  user_id                  :integer          not null
+#  session_id               :string           not null
+#  created_at               :datetime         not null
+#  updated_at               :datetime         not null
+#  user_agent               :string           default(""), not null
+#  ip                       :inet
+#  access_token_id          :integer
+#  web_push_subscription_id :integer
+#
+
 #  id              :integer          not null, primary key
 #  user_id         :integer          not null
 #  session_id      :string           not null
@@ -15,6 +26,7 @@
 
 class SessionActivation < ApplicationRecord
   belongs_to :access_token, class_name: 'Doorkeeper::AccessToken', dependent: :destroy
+  belongs_to :web_push_subscription, class_name: 'Web::PushSubscription', dependent: :destroy
 
   delegate :token,
            to: :access_token,
diff --git a/app/models/user.rb b/app/models/user.rb
index 86e578225..a63b1da7f 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -113,6 +113,10 @@ class User < ApplicationRecord
     session_activations.active? id
   end
 
+  def web_push_subscription(session)
+    session.web_push_subscription.nil? ? nil : session.web_push_subscription.as_payload
+  end
+
   protected
 
   def send_devise_notification(notification, *args)
diff --git a/app/models/web/push_subscription.rb b/app/models/web/push_subscription.rb
new file mode 100644
index 000000000..4440706a6
--- /dev/null
+++ b/app/models/web/push_subscription.rb
@@ -0,0 +1,190 @@
+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: web_push_subscriptions
+#
+#  id         :integer          not null, primary key
+#  endpoint   :string           not null
+#  key_p256dh :string           not null
+#  key_auth   :string           not null
+#  data       :json
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#
+
+class Web::PushSubscription < ApplicationRecord
+  include RoutingHelper
+  include StreamEntriesHelper
+  include ActionView::Helpers::TranslationHelper
+  include ActionView::Helpers::SanitizeHelper
+
+  has_one :session_activation
+
+  before_create :send_welcome_notification
+
+  def push(notification)
+    return unless pushable? notification
+
+    name = display_name notification.from_account
+    title = title_str(name, notification)
+    body = body_str notification
+    dir = dir_str body
+    url = url_str notification
+    image = image_str notification
+    actions = actions_arr notification
+
+    access_token = actions.empty? ? nil : find_or_create_access_token(notification).token
+    nsfw = notification.target_status.nil? || notification.target_status.spoiler_text.empty? ? nil : notification.target_status.spoiler_text
+
+    # TODO: Make sure that the payload does not exceed 4KB - Webpush::PayloadTooLarge
+    # TODO: Queue the requests - Webpush::TooManyRequests
+    Webpush.payload_send(
+      message: JSON.generate(
+        title: title,
+        dir: dir,
+        image: image,
+        badge: full_asset_url('badge.png'),
+        tag: notification.id,
+        timestamp: notification.created_at,
+        icon: notification.from_account.avatar_static_url,
+        data: {
+          content: decoder.decode(strip_tags(body)),
+          nsfw: nsfw.nil? ? nil : decoder.decode(strip_tags(nsfw)),
+          url: url,
+          actions: actions,
+          access_token: access_token,
+        }
+      ),
+      endpoint: endpoint,
+      p256dh: key_p256dh,
+      auth: key_auth,
+      vapid: {
+        # subject: "mailto:#{Setting.site_contact_email}",
+        private_key: Rails.configuration.x.vapid_private_key,
+        public_key: Rails.configuration.x.vapid_public_key,
+      },
+      ttl: 40 * 60 * 60 # 48 hours
+    )
+  end
+
+  def as_payload
+    payload = {
+      id: id,
+      endpoint: endpoint,
+    }
+
+    payload[:alerts] = data['alerts'] if data && data.key?('alerts')
+
+    payload
+  end
+
+  private
+
+  def title_str(name, notification)
+    case notification.type
+    when :mention then translate('push_notifications.mention.title', name: name)
+    when :follow then translate('push_notifications.follow.title', name: name)
+    when :favourite then translate('push_notifications.favourite.title', name: name)
+    when :reblog then translate('push_notifications.reblog.title', name: name)
+    end
+  end
+
+  def body_str(notification)
+    case notification.type
+    when :mention then notification.target_status.text
+    when :follow then notification.from_account.note
+    when :favourite then notification.target_status.text
+    when :reblog then notification.target_status.text
+    end
+  end
+
+  def url_str(notification)
+    case notification.type
+    when :mention then web_url("statuses/#{notification.target_status.id}")
+    when :follow then web_url("accounts/#{notification.from_account.id}")
+    when :favourite then web_url("statuses/#{notification.target_status.id}")
+    when :reblog then web_url("statuses/#{notification.target_status.id}")
+    end
+  end
+
+  def actions_arr(notification)
+    actions =
+      case notification.type
+      when :mention then [
+        {
+          title: translate('push_notifications.mention.action_favourite'),
+          icon: full_asset_url('emoji/2764.png'),
+          todo: 'request',
+          method: 'POST',
+          action: "/api/v1/statuses/#{notification.target_status.id}/favourite",
+        },
+      ]
+      else []
+      end
+
+    should_hide = notification.type.equal?(:mention) && !notification.target_status.nil? && (notification.target_status.sensitive || !notification.target_status.spoiler_text.empty?)
+    can_boost = notification.type.equal?(:mention) && !notification.target_status.nil? && !notification.target_status.hidden?
+
+    if should_hide
+      actions.insert(0, title: translate('push_notifications.mention.action_expand'), icon: full_asset_url('emoji/1f441.png'), todo: 'expand', action: 'expand')
+    end
+
+    if can_boost
+      actions << { title: translate('push_notifications.mention.action_boost'), icon: full_asset_url('emoji/1f504.png'), todo: 'request', method: 'POST', action: "/api/v1/statuses/#{notification.target_status.id}/reblog" }
+    end
+
+    actions
+  end
+
+  def image_str(notification)
+    return nil if notification.target_status.nil? || notification.target_status.media_attachments.empty?
+
+    full_asset_url(notification.target_status.media_attachments.first.file.url(:small))
+  end
+
+  def dir_str(body)
+    rtl?(body) ? 'rtl' : 'ltr'
+  end
+
+  def pushable?(notification)
+    data && data.key?('alerts') && data['alerts'][notification.type.to_s]
+  end
+
+  def send_welcome_notification
+    Webpush.payload_send(
+      message: JSON.generate(
+        title: translate('push_notifications.subscribed.title'),
+        icon: full_asset_url('android-chrome-192x192.png'),
+        badge: full_asset_url('badge.png'),
+        data: {
+          content: translate('push_notifications.subscribed.body'),
+          actions: [],
+          url: web_url('notifications'),
+        }
+      ),
+      endpoint: endpoint,
+      p256dh: key_p256dh,
+      auth: key_auth,
+      vapid: {
+        # subject: "mailto:#{Setting.site_contact_email}",
+        private_key: Rails.configuration.x.vapid_private_key,
+        public_key: Rails.configuration.x.vapid_public_key,
+      },
+      ttl: 5 * 60 # 5 minutes
+    )
+  end
+
+  def find_or_create_access_token(notification)
+    Doorkeeper::AccessToken.find_or_create_for(
+      Doorkeeper::Application.find_by(superapp: true),
+      notification.account.user.id,
+      Doorkeeper::OAuth::Scopes.from_string('read write follow'),
+      Doorkeeper.configuration.access_token_expires_in,
+      Doorkeeper.configuration.refresh_token_enabled?
+    )
+  end
+
+  def decoder
+    @decoder ||= HTMLEntities.new
+  end
+end