AmazonSnsInfo Model Setup

amazon_sns_info.rb

# In db/migrate/XXXXXXX_create_amazon_sns_infos.rb

class CreateAmazonSnsInfos < ActiveRecord::Migration
  def change
    create_table :amazon_sns_infos do |t|
      t.references :user, :foreign_key => true, :index => true, :null => false
      t.string :platform
      t.string :device_token
      t.string :endpoint_arn
      t.string :platform_application_arn
      t.string :env

      t.timestamps null: false
    end
  end
end

######################################################

# In app/models/user.rb

class User < ActiveRecord::Base
  ...
  has_many :amazon_sns_infos
  ...
end

######################################################

# In app/models/amazon_sns_info.rb

class AmazonSnsInfo < ActiveRecord::Base
  belongs_to :user

  store :subscribed_topics, :accessors => [:subscription_arns], :coder => JSON

  validates_presence_of :user

  before_destroy :delete_amazon_sns_platform_endpoint

  def update_topic_subscription
    if self.endpoint_arn.present?
      subscription_arns = AmazonSnsWrapper.subscribe_amazon_sns_topic(self)

      if subscription_arns.present?
        self.subscribed_topics[:subscription_arns] = subscription_arns
      else
        # device need to confirm the subscription with callback token
        # currently amazon return the `subscription_arn` then no need to confirm the subscription
        self.subscribed_topics = nil
      end
    else
      update_endpoint_registration
    end

    self.save!
  end

  def unsubscribe_topic_subscriptions
    unsubscribed_topic_arns = AmazonSnsWrapper.unsubscribe_amazon_sns_topic(self)
    self.subscribed_topics[:subscription_arns] -= unsubscribed_topic_arns if self.subscribed_topics[:subscription_arns].present?
    self.save!
  end

  private

  def delete_amazon_sns_platform_endpoint
    if AmazonSnsWrapper.check_amazon_sns_platform_endpoint(self)
      AmazonSnsWrapper.unsubscribe_amazon_sns_topic(self)
      AmazonSnsWrapper.delete_amazon_sns_platform_endpoint(self)
    end
  end

  def update_endpoint_registration
    unless AmazonSnsWrapper.check_amazon_sns_platform_endpoint(self)
      endpoint_arn = AmazonSnsWrapper.create_amazon_sns_platform_endpoint(self)
      self.endpoint_arn = endpoint_arn
      self.platform_application_arn = AmazonSnsWrapper::AWS_SNS_CONFIG[self.platform.to_sym]
      self.env = Rails.env
      self.save
    end

    self.update_topic_subscription
  end
end