Load system notification policy defaults for new user. Fixes #9737

When a new user visits /profile/communication, load the
system defaults for frequency settings.

Test Plan
=======
* Create a new user and visit /profile/communication.
  Verify that there are default settings loaded.
* Verify that after adding a new communication channel
  that defaults are not applied.
* Verify that changing a setting and reloading
  preserves the user-selected value and is not
  overriden by a default.

Change-Id: I9d87b316510fd08bdf40380e05b327bed7e0e95c
Reviewed-on: https://gerrit.instructure.com/12720
Reviewed-by: Jon Jensen <jon@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>

app/controllers/profile_controller.rb

@@ -119,13 +119,16 @@ class ProfileController < ApplicationController
   def communication
     @user = @current_user
     @user = User.find(params[:id]) if params[:id]
+    @current_user.used_feature(:cc_prefs)
     @context = @user.profile
     @active_tab = 'notifications'
 
+    # Get the list of Notification models (that are treated like categories) that make up the full list of Categories.
+    full_category_list = Notification.dashboard_categories(@user)
     js_env  :NOTIFICATION_PREFERENCES_OPTIONS => {
       :channels => @user.communication_channels.all_ordered_for_display(@user).map { |c| communication_channel_json(c, @user, session) },
-      :policies => NotificationPolicy.scoped(:include => :notification).for(@user).map{ |p| notification_policy_json(p, @user, session) },
-      :categories => Notification.dashboard_categories(@user).map{ |c| notification_category_json(c, @user, session) },
+      :policies => NotificationPolicy.setup_with_default_policies(@user, full_category_list).map{ |p| notification_policy_json(p, @user, session) },
+      :categories => full_category_list.map{ |c| notification_category_json(c, @user, session) },
       :update_url => communication_update_profile_path
     }
   end

app/models/notification_policy.rb

@@ -131,4 +131,33 @@ class NotificationPolicy < ActiveRecord::Base
     end #if..else
     nil
   end
+
+  # Fetch the user's NotificationPolicies but whenever a category is not represented, create a NotificationPolicy on the primary
+  # CommunicationChannel with a default frequency set.
+  # Returns the full list of policies for the user
+  #
+  # ===== Arguments
+  # * <tt>user</tt> - The User instance to load the values for.
+  # * <tt>full_category_list</tt> - An array of Notification models that represent the unique list of categories that should be displayed for the user.
+  #
+  # ===== Returns
+  # A list of NotificationPolicy entries for the user. May include newly created entries if defaults were needed.
+  def self.setup_with_default_policies(user, full_category_list)
+    categories = {}
+    # Get the list of notification categories and its default. Like this: {"Announcement" => 'immediately'}
+    full_category_list.each {|c| categories[c.category] = c.default_frequency}
+    default_channel_id = user.communication_channel.try(:id)
+    # Load unique list of categories that the user currently has settings for.
+    user_categories = NotificationPolicy.for(user).scoped(:joins => :notification,
+                                                          :select => 'DISTINCT notifications.category').all.map{|c| c.category}
+    missing_categories = (categories.keys - user_categories)
+    missing_categories.each do |need_category|
+      # Create the settings for a completely unrepresented category. Use default communication_channel (primary email)
+      self.setup_for(user, {:category => need_category,
+                            :channel_id => default_channel_id,
+                            :frequency => categories[need_category]})
+    end
+    # Load and return user's policies after defaults may or may not have been set.
+    NotificationPolicy.scoped(:include => :notification).for(user)
+  end
 end

spec/models/notification_policy_spec.rb

@@ -225,6 +225,48 @@ describe NotificationPolicy do
       n2.frequency.should == Notification::FREQ_IMMEDIATELY
     end
   end
+
+  describe "setup_with_default_policies" do
+    before :each do
+      user_model
+      communication_channel_model(:user_id => @user.id)
+      @announcement = notification_model(:name => 'Setting 1', :category => 'Announcement')
+    end
+    it "should create default NotificationPolicy entries if missing" do
+      # Ensure no existing policies
+      NotificationPolicy.delete_all
+
+      policies = NotificationPolicy.setup_with_default_policies(@user, [@announcement])
+      policies.length.should == 1
+      policies.first.frequency.should == @announcement.default_frequency
+    end
+    it "should not overwrite an existing setting with a default" do
+      # Create an existing policy entry
+      NotificationPolicy.delete_all
+      n1 = notification_policy_model({:communication_channel => @communication_channel,
+                                      :notification => @announcement,
+                                      :frequency => Notification::FREQ_NEVER})
+
+      @announcement.default_frequency.should_not == Notification::FREQ_NEVER # verify that it differs from the default
+      policies = NotificationPolicy.setup_with_default_policies(@user, [@announcement])
+      policies.length.should == 1
+      policies.first.frequency.should == Notification::FREQ_NEVER
+    end
+    it "should not set defaults on secondary communication channel" do
+      NotificationPolicy.delete_all
+      # Setup the second channel (higher position)
+      primary_channel   = @user.communication_channel
+      secondary_channel = communication_channel_model(:user_id => @user.id, :path => 'secondary@example.com')
+      # start out with 0 on primary and secondary
+      primary_channel.notification_policies.count.should == 0
+      secondary_channel.notification_policies.count.should == 0
+      # Load data
+      NotificationPolicy.setup_with_default_policies(@user, [@announcement])
+      # Primary should have 1 created and secondary should be left alone.
+      primary_channel.notification_policies.count.should == 1
+      secondary_channel.notification_policies.count.should == 0
+    end
+  end
 end
 
 def policy_setup