From a13a474c239c77d523cf95ec5b6404396bdcf940 Mon Sep 17 00:00:00 2001
From: Sojan Jose <sojan@pepalo.com>
Date: Fri, 5 Jun 2020 00:15:50 +0530
Subject: [PATCH] Chore: Firebase Cloud Messaging Support (#858)

---
 .env.example                                  |  3 ++
 Gemfile                                       |  1 +
 Gemfile.lock                                  |  3 ++
 .../notification_subscription_builder.rb      |  2 ++
 app/models/notification_subscription.rb       |  2 +-
 .../notification/push_notification_service.rb | 18 ++++++++++-
 .../push_notification_service_spec.rb         | 32 +++++++++++++++++++
 7 files changed, 59 insertions(+), 2 deletions(-)
 create mode 100644 spec/services/notification/push_notification_service_spec.rb

diff --git a/.env.example b/.env.example
index d4fb1ea12..e8ec635f0 100644
--- a/.env.example
+++ b/.env.example
@@ -102,6 +102,9 @@ CHARGEBEE_WEBHOOK_PASSWORD=
 ## generate a new key value here : https://d3v.one/vapid-key-generator/
 # VAPID_PUBLIC_KEY=
 # VAPID_PRIVATE_KEY=
+#
+# for mobile apps 
+# FCM_SERVER_KEY=
 
 ## Bot Customizations
 USE_INBOX_AVATAR_FOR_BOT=true
diff --git a/Gemfile b/Gemfile
index 50e3e2ce8..6d16179ea 100644
--- a/Gemfile
+++ b/Gemfile
@@ -84,6 +84,7 @@ gem 'sidekiq'
 gem 'flag_shih_tzu'
 
 ##-- Push notification service --##
+gem 'fcm'
 gem 'webpush'
 
 group :development do
diff --git a/Gemfile.lock b/Gemfile.lock
index 48e4e12a8..d8979b903 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -189,6 +189,8 @@ GEM
       multipart-post (>= 1.2, < 3)
     faraday_middleware (1.0.0)
       faraday (~> 1.0)
+    fcm (1.0.1)
+      faraday (~> 1.0.0)
     ffi (1.12.2)
     flag_shih_tzu (0.3.23)
     foreman (0.87.1)
@@ -547,6 +549,7 @@ DEPENDENCIES
   facebook-messenger
   factory_bot_rails
   faker
+  fcm
   flag_shih_tzu
   foreman
   google-cloud-storage
diff --git a/app/builders/notification_subscription_builder.rb b/app/builders/notification_subscription_builder.rb
index 05b0bf984..3326b5cde 100644
--- a/app/builders/notification_subscription_builder.rb
+++ b/app/builders/notification_subscription_builder.rb
@@ -12,6 +12,8 @@ class NotificationSubscriptionBuilder
 
   def identifier
     @identifier ||= params[:subscription_attributes][:endpoint] if params[:subscription_type] == 'browser_push'
+    @identifier ||= params[:device_id] if params[:subscription_type] == 'fcm'
+    @identifier
   end
 
   def identifier_subscription
diff --git a/app/models/notification_subscription.rb b/app/models/notification_subscription.rb
index 534bced01..dbe148f71 100644
--- a/app/models/notification_subscription.rb
+++ b/app/models/notification_subscription.rb
@@ -22,7 +22,7 @@ class NotificationSubscription < ApplicationRecord
 
   SUBSCRIPTION_TYPES = {
     browser_push: 1,
-    gcm: 2
+    fcm: 2
   }.freeze
 
   enum subscription_type: SUBSCRIPTION_TYPES
diff --git a/app/services/notification/push_notification_service.rb b/app/services/notification/push_notification_service.rb
index e01d19679..c29796d64 100644
--- a/app/services/notification/push_notification_service.rb
+++ b/app/services/notification/push_notification_service.rb
@@ -7,7 +7,8 @@ class Notification::PushNotificationService
     return unless user_subscribed_to_notification?
 
     notification_subscriptions.each do |subscription|
-      send_browser_push(subscription) if subscription.browser_push?
+      send_browser_push(subscription)
+      send_fcm_push(subscription)
     end
   end
 
@@ -53,6 +54,8 @@ class Notification::PushNotificationService
   end
 
   def send_browser_push(subscription)
+    return unless subscription.browser_push?
+
     Webpush.payload_send(
       message: JSON.generate(push_message),
       endpoint: subscription.subscription_attributes['endpoint'],
@@ -70,4 +73,17 @@ class Notification::PushNotificationService
   rescue Webpush::ExpiredSubscription
     subscription.destroy!
   end
+
+  def send_fcm_push(subscription)
+    return unless subscription.fcm?
+
+    fcm = FCM.new(ENV['FCM_SERVER_KEY'])
+    options = { "notification": {
+      "title": notification.notification_type.titleize,
+      "body": push_message_title,
+      "notification": notification.to_json
+    } }
+    response = fcm.send([subscription.subscription_attributes['push_token']], options)
+    subscription.destroy! if JSON.parse(response[:body])['results']&.first&.keys&.include?('error')
+  end
 end
diff --git a/spec/services/notification/push_notification_service_spec.rb b/spec/services/notification/push_notification_service_spec.rb
new file mode 100644
index 000000000..67fc9f999
--- /dev/null
+++ b/spec/services/notification/push_notification_service_spec.rb
@@ -0,0 +1,32 @@
+require 'rails_helper'
+
+describe Notification::PushNotificationService do
+  let!(:account) { create(:account) }
+  let!(:user) { create(:user, account: account) }
+  let!(:notification) { create(:notification, user: user, account: user.accounts.first) }
+  let(:fcm_double) { double }
+
+  before do
+    allow(Webpush).to receive(:payload_send).and_return(true)
+    allow(FCM).to receive(:new).and_return(fcm_double)
+    allow(fcm_double).to receive(:send).and_return({ body: { 'results': [] }.to_json })
+  end
+
+  describe '#perform' do
+    it 'sends webpush notifications for webpush subscription' do
+      create(:notification_subscription, user: notification.user)
+
+      described_class.new(notification: notification).perform
+      expect(Webpush).to have_received(:payload_send)
+      expect(FCM).not_to have_received(:new)
+    end
+
+    it 'sends a fcm notification for firebase subscription' do
+      create(:notification_subscription, user: notification.user, subscription_type: 'fcm')
+
+      described_class.new(notification: notification).perform
+      expect(FCM).to have_received(:new)
+      expect(Webpush).not_to have_received(:payload_send)
+    end
+  end
+end