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

42 files changed, 890 insertions, 14 deletions

diff --git a/.env.production.sample b/.env.production.sample
index 394cdedfef8..faefa24829e 100644
--- a/.env.production.sample
+++ b/.env.production.sample
@@ -31,6 +31,17 @@ PAPERCLIP_SECRET=
 SECRET_KEY_BASE=
 OTP_SECRET=
 
+# VAPID keys (used for push notifications
+# You can generate the keys using the following command (first is the private key, second is the public one)
+# You should only generate this once per instance. If you later decide to change it, all push subscription will
+# be invalidated, requiring the users to access the website again to resubscribe.
+#
+# ruby -e "require 'webpush'; vapid_key = Webpush.generate_key; puts vapid_key.private_key; puts vapid_key.public_key;"
+#
+# For more information visit https://rossta.net/blog/using-the-web-push-api-with-vapid.html
+VAPID_PRIVATE_KEY=
+VAPID_PUBLIC_KEY=
+
 # Registrations
 # Single user mode will disable registrations and redirect frontpage to the first profile
 # SINGLE_USER_MODE=true
diff --git a/.gitignore b/.gitignore
index 38ebc934f28..868a843682f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,6 +21,7 @@ public/system
 public/assets
 public/packs
 public/packs-test
+public/sw.js
 .env
 .env.production
 node_modules/
diff --git a/Gemfile b/Gemfile
index b52685cba98..988b4d6b981 100644
--- a/Gemfile
+++ b/Gemfile
@@ -64,6 +64,7 @@ gem 'statsd-instrument', '~> 2.1'
 gem 'twitter-text', '~> 1.14'
 gem 'tzinfo-data', '~> 1.2017'
 gem 'webpacker', '~> 2.0'
+gem 'webpush'
 
 group :development, :test do
   gem 'fabrication', '~> 2.16'
diff --git a/Gemfile.lock b/Gemfile.lock
index de0d6a10723..5599e1db160 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -181,6 +181,7 @@ GEM
     hashdiff (0.3.4)
     highline (1.7.8)
     hiredis (0.6.1)
+    hkdf (0.3.0)
     htmlentities (4.3.4)
     http (2.2.2)
       addressable (~> 2.3)
@@ -209,6 +210,7 @@ GEM
     jmespath (1.3.1)
     json (2.1.0)
     jsonapi-renderer (0.1.2)
+    jwt (1.5.6)
     kaminari (1.0.1)
       activesupport (>= 4.1.0)
       kaminari-actionview (= 1.0.1)
@@ -475,6 +477,9 @@ GEM
       activesupport (>= 4.2)
       multi_json (~> 1.2)
       railties (>= 4.2)
+    webpush (0.3.2)
+      hkdf (~> 0.2)
+      jwt
     websocket-driver (0.6.5)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.2)
@@ -573,6 +578,7 @@ DEPENDENCIES
   uglifier (~> 3.2)
   webmock (~> 3.0)
   webpacker (~> 2.0)
+  webpush
 
 RUBY VERSION
    ruby 2.4.1p111
diff --git a/app/controllers/api/web/push_subscriptions_controller.rb b/app/controllers/api/web/push_subscriptions_controller.rb
new file mode 100644
index 00000000000..8425db7b45e
--- /dev/null
+++ b/app/controllers/api/web/push_subscriptions_controller.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+class Api::Web::PushSubscriptionsController < Api::BaseController
+  respond_to :json
+
+  before_action :require_user!
+
+  def create
+    params.require(:data).require(:endpoint)
+    params.require(:data).require(:keys).require([:auth, :p256dh])
+
+    active_session = current_session
+
+    unless active_session.web_push_subscription.nil?
+      active_session.web_push_subscription.destroy!
+      active_session.update!(web_push_subscription: nil)
+    end
+
+    web_subscription = ::Web::PushSubscription.create!(
+      endpoint: params[:data][:endpoint],
+      key_p256dh: params[:data][:keys][:p256dh],
+      key_auth: params[:data][:keys][:auth]
+    )
+
+    active_session.update!(web_push_subscription: web_subscription)
+
+    render json: web_subscription.as_payload
+  end
+
+  def update
+    params.require([:id, :data])
+
+    web_subscription = ::Web::PushSubscription.find(params[:id])
+
+    web_subscription.update!(data: params[:data])
+
+    render json: web_subscription.as_payload
+  end
+end
diff --git a/app/controllers/home_controller.rb b/app/controllers/home_controller.rb
index 8a8b9ec76ba..1585bc81052 100644
--- a/app/controllers/home_controller.rb
+++ b/app/controllers/home_controller.rb
@@ -22,6 +22,7 @@ class HomeController < ApplicationController
   def initial_state_params
     {
       settings: Web::Setting.find_by(user: current_user)&.data || {},
+      push_subscription: current_account.user.web_push_subscription(current_session),
       current_account: current_account,
       token: current_session.token,
       admin: Account.find_local(Setting.site_contact_username),
diff --git a/app/javascript/mastodon/actions/push_notifications.js b/app/javascript/mastodon/actions/push_notifications.js
new file mode 100644
index 00000000000..55661d2b090
--- /dev/null
+++ b/app/javascript/mastodon/actions/push_notifications.js
@@ -0,0 +1,52 @@
+import axios from 'axios';
+
+export const SET_BROWSER_SUPPORT = 'PUSH_NOTIFICATIONS_SET_BROWSER_SUPPORT';
+export const SET_SUBSCRIPTION = 'PUSH_NOTIFICATIONS_SET_SUBSCRIPTION';
+export const CLEAR_SUBSCRIPTION = 'PUSH_NOTIFICATIONS_CLEAR_SUBSCRIPTION';
+export const ALERTS_CHANGE = 'PUSH_NOTIFICATIONS_ALERTS_CHANGE';
+
+export function setBrowserSupport (value) {
+  return {
+    type: SET_BROWSER_SUPPORT,
+    value,
+  };
+}
+
+export function setSubscription (subscription) {
+  return {
+    type: SET_SUBSCRIPTION,
+    subscription,
+  };
+}
+
+export function clearSubscription () {
+  return {
+    type: CLEAR_SUBSCRIPTION,
+  };
+}
+
+export function changeAlerts(key, value) {
+  return dispatch => {
+    dispatch({
+      type: ALERTS_CHANGE,
+      key,
+      value,
+    });
+
+    dispatch(saveSettings());
+  };
+}
+
+export function saveSettings() {
+  return (_, getState) => {
+    const state = getState().get('push_notifications');
+    const subscription = state.get('subscription');
+    const alerts = state.get('alerts');
+
+    axios.put(`/api/web/push_subscriptions/${subscription.get('id')}`, {
+      data: {
+        alerts,
+      },
+    });
+  };
+}
diff --git a/app/javascript/mastodon/features/notifications/components/column_settings.js b/app/javascript/mastodon/features/notifications/components/column_settings.js
index 26059489477..31cac5bc7a8 100644
--- a/app/javascript/mastodon/features/notifications/components/column_settings.js
+++ b/app/javascript/mastodon/features/notifications/components/column_settings.js
@@ -9,18 +9,27 @@ export default class ColumnSettings extends React.PureComponent {
 
   static propTypes = {
     settings: ImmutablePropTypes.map.isRequired,
+    pushSettings: ImmutablePropTypes.map.isRequired,
     onChange: PropTypes.func.isRequired,
     onSave: PropTypes.func.isRequired,
     onClear: PropTypes.func.isRequired,
   };
 
+  onPushChange = (key, checked) => {
+    this.props.onChange(['push', ...key], checked);
+  }
+
   render () {
-    const { settings, onChange, onClear } = this.props;
+    const { settings, pushSettings, onChange, onClear } = this.props;
 
     const alertStr = <FormattedMessage id='notifications.column_settings.alert' defaultMessage='Desktop notifications' />;
     const showStr  = <FormattedMessage id='notifications.column_settings.show' defaultMessage='Show in column' />;
     const soundStr = <FormattedMessage id='notifications.column_settings.sound' defaultMessage='Play sound' />;
 
+    const showPushSettings = pushSettings.get('browserSupport') && pushSettings.get('isSubscribed');
+    const pushStr = showPushSettings && <FormattedMessage id='notifications.column_settings.push' defaultMessage='Push notifications' />;
+    const pushMeta = showPushSettings && <FormattedMessage id='notifications.column_settings.push_meta' defaultMessage='This device' />;
+
     return (
       <div>
         <div className='column-settings__row'>
@@ -30,7 +39,8 @@ export default class ColumnSettings extends React.PureComponent {
         <span className='column-settings__section'><FormattedMessage id='notifications.column_settings.follow' defaultMessage='New followers:' /></span>
 
         <div className='column-settings__row'>
-          <SettingToggle prefix='notifications' settings={settings} settingKey={['alerts', 'follow']} onChange={onChange} label={alertStr} />
+          <SettingToggle prefix='notifications_desktop' settings={settings} settingKey={['alerts', 'follow']} onChange={onChange} label={alertStr} />
+          {showPushSettings && <SettingToggle prefix='notifications_push' settings={pushSettings} settingKey={['alerts', 'follow']} meta={pushMeta} onChange={this.onPushChange} label={pushStr} />}
           <SettingToggle prefix='notifications' settings={settings} settingKey={['shows', 'follow']} onChange={onChange} label={showStr} />
           <SettingToggle prefix='notifications' settings={settings} settingKey={['sounds', 'follow']} onChange={onChange} label={soundStr} />
         </div>
@@ -38,7 +48,8 @@ export default class ColumnSettings extends React.PureComponent {
         <span className='column-settings__section'><FormattedMessage id='notifications.column_settings.favourite' defaultMessage='Favourites:' /></span>
 
         <div className='column-settings__row'>
-          <SettingToggle prefix='notifications' settings={settings} settingKey={['alerts', 'favourite']} onChange={onChange} label={alertStr} />
+          <SettingToggle prefix='notifications_desktop' settings={settings} settingKey={['alerts', 'favourite']} onChange={onChange} label={alertStr} />
+          {showPushSettings && <SettingToggle prefix='notifications_push' settings={pushSettings} settingKey={['alerts', 'favourite']} meta={pushMeta} onChange={this.onPushChange} label={pushStr} />}
           <SettingToggle prefix='notifications' settings={settings} settingKey={['shows', 'favourite']} onChange={onChange} label={showStr} />
           <SettingToggle prefix='notifications' settings={settings} settingKey={['sounds', 'favourite']} onChange={onChange} label={soundStr} />
         </div>
@@ -46,7 +57,8 @@ export default class ColumnSettings extends React.PureComponent {
         <span className='column-settings__section'><FormattedMessage id='notifications.column_settings.mention' defaultMessage='Mentions:' /></span>
 
         <div className='column-settings__row'>
-          <SettingToggle prefix='notifications' settings={settings} settingKey={['alerts', 'mention']} onChange={onChange} label={alertStr} />
+          <SettingToggle prefix='notifications_desktop' settings={settings} settingKey={['alerts', 'mention']} onChange={onChange} label={alertStr} />
+          {showPushSettings && <SettingToggle prefix='notifications_push' settings={pushSettings} settingKey={['alerts', 'mention']} meta={pushMeta} onChange={this.onPushChange} label={pushStr} />}
           <SettingToggle prefix='notifications' settings={settings} settingKey={['shows', 'mention']} onChange={onChange} label={showStr} />
           <SettingToggle prefix='notifications' settings={settings} settingKey={['sounds', 'mention']} onChange={onChange} label={soundStr} />
         </div>
@@ -54,7 +66,8 @@ export default class ColumnSettings extends React.PureComponent {
         <span className='column-settings__section'><FormattedMessage id='notifications.column_settings.reblog' defaultMessage='Boosts:' /></span>
 
         <div className='column-settings__row'>
-          <SettingToggle prefix='notifications' settings={settings} settingKey={['alerts', 'reblog']} onChange={onChange} label={alertStr} />
+          <SettingToggle prefix='notifications_desktop' settings={settings} settingKey={['alerts', 'reblog']} onChange={onChange} label={alertStr} />
+          {showPushSettings && <SettingToggle prefix='notifications_push' settings={pushSettings} settingKey={['alerts', 'reblog']} meta={pushMeta} onChange={this.onPushChange} label={pushStr} />}
           <SettingToggle prefix='notifications' settings={settings} settingKey={['shows', 'reblog']} onChange={onChange} label={showStr} />
           <SettingToggle prefix='notifications' settings={settings} settingKey={['sounds', 'reblog']} onChange={onChange} label={soundStr} />
         </div>
diff --git a/app/javascript/mastodon/features/notifications/components/setting_toggle.js b/app/javascript/mastodon/features/notifications/components/setting_toggle.js
index 5108203587f..be1ff91d666 100644
--- a/app/javascript/mastodon/features/notifications/components/setting_toggle.js
+++ b/app/javascript/mastodon/features/notifications/components/setting_toggle.j