Restructure how content is linked to users

De-normalize the database to store the last content that users received
on the user. This makes it easier to know what to send the user next,
and reduces the reliance on their age in months. This was causing issues
where the child would turn a month older at the beginning of each month,
and depending on when they had signed up it meant they were missing
content.

app/controllers/contents_controller.rb

@@ -44,6 +44,6 @@ def destroy
   private
 
   def content_params
-    params.require(:content).permit(:body, :link, :position, :welcome_message)
+    params.require(:content).permit(:body, :link, :position, :welcome_message, :age_in_months)
   end
 end

app/controllers/groups_controller.rb

@@ -1,6 +1,6 @@
 class GroupsController < ApplicationController
   def index
-    @groups = Group.order(:age_in_months)
+    @groups = Group.all
   end
 
   def show
@@ -44,6 +44,6 @@ def destroy
   private
 
   def group_params
-    params.require(:group).permit(:name, :age_in_months)
+    params.require(:group).permit(:name)
   end
 end

app/jobs/send_bulk_message_job.rb

@@ -1,10 +1,8 @@
 class SendBulkMessageJob < ApplicationJob
   queue_as :default
 
-  def perform(users, group)
-    return unless group.present?
-
-    message_jobs = users.map { |user| SendMessageJob.new(user, group) }
+  def perform(users)
+    message_jobs = users.map { |user| SendMessageJob.new(user) }
 
     ActiveJob.perform_all_later(message_jobs)
   end

app/jobs/send_message_job.rb

@@ -3,8 +3,8 @@ class SendMessageJob < ApplicationJob
 
   queue_as :default
 
-  def perform(user, group)
-    content = user.next_content(group)
+  def perform(user)
+    content = user.next_content
 
     return unless content.present?
     # If BulkMessage fails and reruns this job, don't send them the next message
@@ -18,6 +18,17 @@ def perform(user, group)
       m.content = content
     end
 
-    Twilio::Client.new.send_message(message) if message.save
+    Twilio::Client.new.send_message(message) if save_user_and_message(user, message, content)
+  end
+
+  private
+
+  def save_user_and_message(user, message, content)
+    ActiveRecord::Base.transaction do
+      user.update(last_content_id: content.id)
+      message.save
+    rescue ActiveRecord::RecordInvalid
+      false
+    end
   end
 end

app/jobs/send_welcome_message_job.rb

@@ -4,14 +4,14 @@ class SendWelcomeMessageJob < ApplicationJob
   queue_as :default
 
   def perform(user)
-    group = Group.find_by(age_in_months: user.child_age_in_months_today)
+    content = Content.find_by(age_in_months: user.child_age_in_months_today, welcome_message: true)
 
-    message = if group.present? && group.welcome_message.present?
+    message = if content.present?
       Message.create do |m|
         m.token = m.send(:generate_token)
-        m.link = group.welcome_message.link
+        m.link = content.link
         m.user = user
-        m.body = group.welcome_message.body.gsub("{{link}}", track_link_url(m.token))
+        m.body = content.body.gsub("{{link}}", track_link_url(m.token))
       end
     else
       Message.create do |m|

app/models/content.rb

@@ -4,5 +4,5 @@ class Content < ApplicationRecord
 
   has_many :messages, dependent: :nullify
 
-  validates_presence_of :body, :link
+  validates_presence_of :body, :link, :age_in_months
 end

app/models/group.rb

@@ -1,11 +1,7 @@
 class Group < ApplicationRecord
   has_many :contents, dependent: :destroy
 
-  validates :name, :age_in_months, presence: true
-
-  def welcome_message
-    contents.find_by(welcome_message: true)
-  end
+  validates :name, presence: true
 
   def weekly_content
     contents.where(welcome_message: false)

app/models/user.rb

@@ -55,13 +55,38 @@ def full_name
     "#{first_name} #{last_name}"
   end
 
-  def next_content(group)
-    return unless group.present?
-    # find lowest ranked content minus any they have already seen
-    (group.weekly_content - contents).min_by(&:position)
+  def next_content
+    if had_any_content_before?
+      find_next_unseen_content
+    else
+      Content.where(age_in_months: child_age_in_months_today, welcome_message: false).min_by(&:position)
+    end
   end
 
   def had_content_this_week?
     messages.where("created_at > ?", 6.days.ago).where.not(content: nil).exists?
   end
+
+  private
+
+  def had_any_content_before?
+    last_content_id.present?
+  end
+
+  def not_seen_content?(content)
+    messages.where(content_id: content.id).none?
+  end
+
+  def find_next_unseen_content
+    i = Content.find(last_content_id).position + 1
+
+    loop do
+      content = Content.find_by(position: i)
+      # Last message in series
+      return nil if content.nil?
+      # Next message
+      return content if not_seen_content?(content)
+      i += 1
+    end
+  end
 end

app/views/contents/_form.html.erb

@@ -3,6 +3,10 @@
     <%= form.input :body, as: :text, input_html: { class: "w-full", rows: 5 }, hint: "To put the link in the message body, use {{link}}" %>
   </div>
 
+  <div class="mt-3">
+    <%= form.input :age_in_months, wrapper_html: { class: "w-1/2" } %>
+  </div>
+
   <div class="mt-3">
     <%= form.input :link %>
   </div>

app/views/groups/_form.html.erb

@@ -3,9 +3,5 @@
     <%= form.input :name %>
   </div>
 
-  <div class="mt-3">
-    <%= form.input :age_in_months %>
-  </div>
-
   <%= form.submit (action_name == "edit" ? "Update" : "Create"), class: "btn btn-primary mt-5 bg-purple-600 text-white w-full" %>
 <% end %>

app/views/groups/index.html.erb

@@ -9,7 +9,6 @@
       <thead>
         <tr class="px-4 py-4 bg-purple-300 text-left">
           <th class="p-4 w-3/4">Content group name</th>
-          <th class="p-4 w-3/4">Child age</th>
           <th class="p-4 w-1/5">No. of messages</th>
           <th>&nbsp</th>
         </tr>
@@ -18,7 +17,6 @@
         <% @groups.each do |group| %>
           <tr class="border-b-2">
             <td class="p-4"><%= link_to group.name, group, class: "underline hover:no-underline" %></td>
-            <td class="p-4"><%= group.age_in_months %> months</td>
             <td class="p-4"><%= group.contents.size %></td>
             <td class="p-4">
               <%= link_to "Edit", edit_group_path(group), class: "underline hover:no-underline" %>

app/views/groups/show.html.erb

@@ -12,8 +12,9 @@
       <thead>
         <tr class="px-4 py-4 bg-purple-300 text-left">
           <th class="p-4"></th>
-          <th class="p-4 w-3/5">Body</th>
-          <th class="p-4 w-2/5">Link</th>
+          <th class="p-4 w-6/12">Body</th>
+          <th class="p-4 w-1/12">Age</th>
+          <th class="p-4 w-5/12">Link</th>
           <th>&nbsp</th>
         </tr>
       </thead>
@@ -31,6 +32,9 @@
               <% end %>
               <%= content.body %>
             </td>
+            <td class="p-4">
+              <%= content.age_in_months %>
+            </td>
             <td class="p-4"><%= content.link %></td>
             <td class="p-4">
               <%= link_to "Edit", edit_group_content_path(@group, content), class: "underline hover:no-underline" %>

db/migrate/20241205095730_add_last_content_to_user.rb

@@ -0,0 +1,5 @@
+class AddLastContentToUser < ActiveRecord::Migration[7.2]
+  def change
+    add_reference :users, :last_content, foreign_key: {to_table: :contents}
+  end
+end

db/migrate/20241205100911_remove_age_from_group.rb

@@ -0,0 +1,12 @@
+class RemoveAgeFromGroup < ActiveRecord::Migration[7.2]
+  def change
+    add_column :contents, :age_in_months, :integer
+
+    Content.find_each do |content|
+      content.update(age_in_months: content.group.age_in_months)
+    end
+
+    remove_column :groups, :age_in_months, :integer
+    change_column_null :contents, :age_in_months, false
+  end
+end

lib/tasks/scheduler.rake

@@ -3,51 +3,35 @@ namespace :scheduler do
   task send_morning_message: :environment do
     (next unless Date.today.wday == ENV.fetch("WEEKLY_MESSAGE_DAY").to_i) if ENV.fetch("SET_WEEKLY") == "true"
 
-    User.contactable.wants_morning_message.group_by(&:adjusted_child_age_in_months_today).each do |age, users|
-      group = Group.find_by(age_in_months: age)
-
-      next unless group
-
-      SendBulkMessageJob.perform_later(users, group)
+    User.contactable.wants_morning_message.find_in_batches do |users|
+      SendBulkMessageJob.perform_later(users)
     end
   end
 
   desc "Send afternoon text message"
   task send_afternoon_message: :environment do
     (next unless Date.today.wday == ENV.fetch("WEEKLY_MESSAGE_DAY").to_i) if ENV.fetch("SET_WEEKLY") == "true"
 
-    User.contactable.wants_afternoon_message.group_by(&:adjusted_child_age_in_months_today).each do |age, users|
-      group = Group.find_by(age_in_months: age)
-
-      next unless group
-
-      SendBulkMessageJob.perform_later(users, group)
+    User.contactable.wants_afternoon_message.find_in_batches do |users|
+      SendBulkMessageJob.perform_later(users)
     end
   end
 
   desc "Send evening text message"
   task send_evening_message: :environment do
     (next unless Date.today.wday == ENV.fetch("WEEKLY_MESSAGE_DAY").to_i) if ENV.fetch("SET_WEEKLY") == "true"
 
-    User.contactable.wants_evening_message.group_by(&:adjusted_child_age_in_months_today).each do |age, users|
-      group = Group.find_by(age_in_months: age)
-
-      next unless group
-
-      SendBulkMessageJob.perform_later(users, group)
+    User.contactable.wants_evening_message.find_in_batches do |users|
+      SendBulkMessageJob.perform_later(users)
     end
   end
 
   desc "Send no timing preference text message"
   task send_no_timing_preference_message: :environment do
     (next unless Date.today.wday == ENV.fetch("WEEKLY_MESSAGE_DAY").to_i) if ENV.fetch("SET_WEEKLY") == "true"
 
-    User.contactable.no_preference_message.group_by(&:adjusted_child_age_in_months_today).each do |age, users|
-      group = Group.find_by(age_in_months: age)
-
-      next unless group
-
-      SendBulkMessageJob.perform_later(users, group)
+    User.contactable.no_preference_message.find_in_batches do |users|
+      SendBulkMessageJob.perform_later(users)
     end
   end
 

test/factories/content.rb

@@ -2,6 +2,7 @@
   factory :content do
     body { "Sample Body" }
     link { "www.example.com" }
+    age_in_months { 18 }
     sequence(:position) { |n| n }
 
     group

test/factories/group.rb

@@ -1,6 +1,5 @@
 FactoryBot.define do
   factory :group do
-    name { "Content for 18 month olds" }
-    age_in_months { 18 }
+    name { "Group" }
   end
 end

test/jobs/send_bulk_message_job_test.rb

@@ -5,20 +5,11 @@ class SendBulkMessageJobTest < ActiveSupport::TestCase
 
   test "#perform creates jobs to send messages to users" do
     users = create_list(:user, 3, child_birthday: 3.months.ago)
-    group = create(:group, age_in_months: 3)
+    group = create(:group)
     create(:content, group:)
 
     assert_enqueued_jobs 3 do
-      SendBulkMessageJob.perform_now(users, group)
-    end
-  end
-
-  test "#perform does not create jobs if group is not present" do
-    users = create_list(:user, 3, child_birthday: 3.months.ago)
-    group = nil
-
-    assert_no_enqueued_jobs do
-      SendBulkMessageJob.perform_now(users, group)
+      SendBulkMessageJob.perform_now(users)
     end
   end
 end