Scheduled job to send push notifications for Post resource

app/jobs/create_push_notifications_job.rb

@@ -6,6 +6,10 @@ def perform(event_id:)
 
     raise 'A valid Event must be provided' unless event
 
-    ::PushNotifications::Creator.new(event: event).create!
+    if event.post_id
+      ::PushNotifications::Creator::Post.new(event: event).create!
+    else
+      raise "You need to define a PushNotifications::Creator class for this event type ##{event.id}"
+    end
   end
 end

app/jobs/send_push_notifications_job.rb

@@ -0,0 +1,11 @@
+class SendPushNotificationsJob < ActiveJob::Base
+  queue_as :cron
+
+  def perform
+    push_notifications = PushNotification.where(processed_at: nil).limit(100)
+
+    ::PushNotifications::Broadcast.new(
+      push_notifications: push_notifications
+    ).send_notifications
+  end
+end

app/models/push_notification.rb

@@ -2,5 +2,7 @@ class PushNotification < ActiveRecord::Base
   belongs_to :event, foreign_key: 'event_id'
   belongs_to :device_token, foreign_key: 'device_token_id'
 
-  validates :event, :device_token, presence: true
+  validates :event, :device_token, :title, presence: true
+
+  delegate :token, to: :device_token
 end

app/services/push_notifications/broadcast.rb

@@ -0,0 +1,58 @@
+module PushNotifications
+  class Broadcast
+    class PostError < ::StandardError; end
+
+    def initialize(push_notifications:)
+      @push_notifications = push_notifications
+    end
+
+    # https://docs.expo.io/versions/latest/guides/push-notifications.html
+    def send_notifications
+      return unless push_notifications.any?
+
+      response = client.post(
+        uri.request_uri,
+        notifications.to_json,
+        headers
+      )
+
+      unless response.is_a? Net::HTTPOK
+        raise PostError, "HTTP response: #{response.code}, #{response.body}"
+      end
+
+      now = Time.now.utc
+      push_notifications.update_all(processed_at: now, updated_at: now)
+    end
+
+    private
+
+    attr_reader :push_notifications
+
+    def notifications
+      push_notifications.map do |push_notification|
+        {
+          to: push_notification.token,
+          title: push_notification.title,
+          body: push_notification.body,
+          data: push_notification.data
+        }
+      end
+    end
+
+    def client
+      https = Net::HTTP.new(uri.host, uri.port)
+      https.use_ssl = true
+      https
+    end
+
+    def uri
+      URI('https://exp.host/--/api/v2/push/send')
+    end
+
+    def headers
+      {
+        "Content-Type" => "application/json"
+      }
+    end
+  end
+end

app/services/push_notifications/creator/base.rb

@@ -0,0 +1,42 @@
+module PushNotifications
+  module Creator
+    class Base
+      # Given an Event it will create as many PushNotification resources
+      # necessary as the resource associated to the Event will require.
+      #
+      # @param [Hash] event: <Event>
+      def initialize(event:)
+        @event = event
+      end
+
+      def create!
+        event_notifier = EventNotifierFactory.new(event: event).build
+        event_notifier.device_tokens.each do |device_token|
+          PushNotification.create!(
+            event: event,
+            device_token: device_token,
+            title: title,
+            body: body,
+            data: data
+          )
+        end
+      end
+
+      private
+
+      attr_accessor :event
+
+      def title
+        raise 'implement the private method `title`'
+      end
+
+      def body
+        raise 'implement the private method `body`'
+      end
+
+      def data
+        raise 'implement the private method `data`'
+      end
+    end
+  end
+end

app/services/push_notifications/creator/post.rb

@@ -0,0 +1,25 @@
+module PushNotifications
+  module Creator
+    class Post < Base
+      private
+
+      def title
+        event.post.title
+      end
+
+      def body
+        event.post.description&.truncate(20) || 'No description'
+      end
+
+      def data
+        if event.post.class.to_s == 'Offer'
+          { url: Rails.application.routes.url_helpers.offer_path(event.post) }
+        elsif event.post.class.to_s == 'Inquiry'
+          { url: Rails.application.routes.url_helpers.inquiry_path(event.post) }
+        else
+          {}
+        end
+      end
+    end
+  end
+end

config/schedule.yml

@@ -0,0 +1,4 @@
+send_push_notifications_job:
+  cron: '*/5 * * * *'
+  class: 'SendPushNotificationsJob'
+  queue: cron

db/migrate/20180604145622_add_title_to_push_notification.rb

@@ -0,0 +1,9 @@
+class AddTitleToPushNotification < ActiveRecord::Migration
+  def up
+    add_column :push_notifications, :title, :string, null: false, default: ''
+  end
+
+  def down
+    remove_column :push_notifications, :title
+  end
+end

db/migrate/20180828160700_add_body_to_push_notification.rb

@@ -0,0 +1,9 @@
+class AddBodyToPushNotification < ActiveRecord::Migration
+  def up
+    add_column :push_notifications, :body, :string, null: false, default: ''
+  end
+
+  def down
+    remove_column :push_notifications, :body
+  end
+end

db/migrate/20180831161349_add_data_to_push_notification.rb

@@ -0,0 +1,9 @@
+class AddDataToPushNotification < ActiveRecord::Migration
+  def up
+    add_column :push_notifications, :data, :json, null: false, default: '{}'
+  end
+
+  def down
+    remove_column :push_notifications, :data
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20180530180546) do
+ActiveRecord::Schema.define(version: 20180831161349) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -159,11 +159,14 @@
   add_index "posts", ["user_id"], name: "index_posts_on_user_id", using: :btree
 
   create_table "push_notifications", force: :cascade do |t|
-    t.integer  "event_id",        null: false
-    t.integer  "device_token_id", null: false
+    t.integer  "event_id",                     null: false
+    t.integer  "device_token_id",              null: false
     t.datetime "processed_at"
-    t.datetime "created_at",      null: false
-    t.datetime "updated_at",      null: false
+    t.datetime "created_at",                   null: false
+    t.datetime "updated_at",                   null: false
+    t.string   "title",           default: "", null: false
+    t.string   "body",            default: "", null: false
+    t.json     "data",            default: {}, null: false
   end
 
   create_table "transfers", force: :cascade do |t|

spec/fabricators/device_token_fabricator.rb

@@ -1,2 +1,3 @@
 Fabricator(:device_token) do
+  token 'token'
 end

spec/fabricators/push_notification_fabricator.rb

@@ -0,0 +1,2 @@
+Fabricator(:push_notification) do
+end

spec/jobs/create_push_notifications_job_spec.rb

@@ -18,8 +18,8 @@
       let(:event_id) { event.id }
 
       it 'calls the PushNotification creator' do
-        creator = instance_double(::PushNotifications::Creator)
-        expect(::PushNotifications::Creator).to receive(:new)
+        creator = instance_double(::PushNotifications::Creator::Post)
+        expect(::PushNotifications::Creator::Post).to receive(:new)
           .with(event: event)
           .and_return(creator)
         expect(creator).to receive(:create!)

spec/jobs/send_push_notifications_job_spec.rb

@@ -0,0 +1,43 @@
+require 'spec_helper'
+
+RSpec.describe SendPushNotificationsJob, type: :job do
+  describe '#perform' do
+    let(:user) { Fabricate(:user) }
+    let(:device_token) { Fabricate(:device_token, user: user) }
+    let(:post) { Fabricate(:post) }
+    let(:event_created) { Fabricate(:event, post: post, action: :created) }
+    let(:event_updated) { Fabricate(:event, post: post, action: :updated) }
+    let(:push_notification) do
+      Fabricate(
+        :push_notification,
+        event: event_created,
+        device_token: device_token,
+        title: 'A new Post hase been created.'
+      )
+    end
+    let(:processed_push_notification) do
+      Fabricate(
+        :push_notification,
+        event: event_updated,
+        device_token: device_token,
+        title: 'A new Post hase been created.',
+        processed_at: Time.zone.now
+      )
+    end
+
+    before do
+      push_notification
+      processed_push_notification
+    end
+
+    it 'calls Broadcast to send the notifications' do
+      broadcast = instance_double(::PushNotifications::Broadcast)
+      expect(::PushNotifications::Broadcast).to receive(:new)
+        .with(push_notifications: [push_notification])
+        .and_return(broadcast)
+      expect(broadcast).to receive(:send_notifications)
+
+      described_class.new.perform
+    end
+  end
+end

spec/models/push_notification_spec.rb

@@ -4,6 +4,7 @@
   describe 'Validations' do
     it { is_expected.to validate_presence_of(:event) }
     it { is_expected.to validate_presence_of(:device_token) }
+    it { is_expected.to validate_presence_of(:title) }
   end
 
   describe 'Associations' do
@@ -13,4 +14,13 @@
     it { is_expected.to have_db_column(:event_id) }
     it { is_expected.to have_db_column(:device_token_id) }
   end
+
+  describe "#token" do
+    let(:device_token) { Fabricate.build(:device_token, token: 'token') }
+    let(:push_notification) { described_class.new(device_token: device_token) }
+
+    it 'returns the associated DeviceToken\'s token' do
+      expect(push_notification.token).to eq('token')
+    end
+  end
 end