Chatwoot/app/services/notification/push_notification_service.rb

class Notification::PushNotificationService
  include Rails.application.routes.url_helpers

  pattr_initialize [:notification!]

  def perform
    return unless user_subscribed_to_notification?

    notification_subscriptions.each do |subscription|
      send_browser_push(subscription)
      send_fcm_push(subscription)
    end
  end

  private

  delegate :user, to: :notification
  delegate :notification_subscriptions, to: :user
  delegate :notification_settings, to: :user

  def user_subscribed_to_notification?
    notification_setting = notification_settings.find_by(account_id: notification.account.id)
    return true if notification_setting.public_send("push_#{notification.notification_type}?")

    false
  end

  def conversation
    @conversation ||= notification.primary_actor
  end

  def push_message_title
    if notification.notification_type == 'conversation_creation'
      return "A new conversation [ID -#{conversation.display_id}] has been created in #{conversation.inbox.name}"
    end

    if notification.notification_type == 'conversation_assignment'
      return "A new conversation [ID -#{conversation.display_id}] has been assigned to you."
    end

    ''
  end

  def push_message
    {
      title: push_message_title,
      tag: "#{notification.notification_type}_#{conversation.display_id}",
      url: push_url
    }
  end

  def push_url
    app_account_conversation_url(account_id: conversation.account_id, id: conversation.display_id)
  end

  def send_browser_push(subscription)
    return unless subscription.browser_push?

    Webpush.payload_send(
      message: JSON.generate(push_message),
      endpoint: subscription.subscription_attributes['endpoint'],
      p256dh: subscription.subscription_attributes['p256dh'],
      auth: subscription.subscription_attributes['auth'],
      vapid: {
        subject: push_url,
        public_key: ENV['VAPID_PUBLIC_KEY'],
        private_key: ENV['VAPID_PRIVATE_KEY']
      },
      ssl_timeout: 5,
      open_timeout: 5,
      read_timeout: 5
    )
  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