big refactor

app/controllers/recommendations_controller.rb

@@ -1,17 +1,23 @@
 class RecommendationsController < ApplicationController
   def index
-    if params[:subtopic].blank?
+    if params[:subtopic].strip.blank?
       flash[:alert] = "Please provide a subtopic parameter: '/recommendations?subtopic=X' or paste the subtopic into the search field above."
       redirect_to root_path and return
     end
 
-    @sub_topic = SubTopic.find_by_subtopic_id params[:subtopic]
-    @recommender = Recommender.new @sub_topic.subtopic_id, params.fetch(:per, 4), params[:page]
+    per = params.fetch :per, 4
+    page = params[:page]
+    results = Recommender.new(params[:subtopic]).solve
+    @recommendations = Kaminari.paginate_array(results).page(page).per per
 
     respond_to do |format|
-      format.html
+      format.html do
+        @sub_topic = SubTopic.find_by_subtopic_id params[:subtopic]
+      end
+
       format.json do
-        render json: { recommended_subtopics: @recommender.ask.map(&:first) }
+        subtopic_ids = @recommendations.map &:first
+        render json: subtopic_ids
       end
     end
   end

app/services/recommender.rb

@@ -1,41 +1,38 @@
 class Recommender
-  def initialize(subtopic_id, per = 4, page = 0)
-    @subtopic_id, @per, @page = subtopic_id, per, page
+  def initialize(subtopic_id)
+    @subtopic_id = subtopic_id
   end
 
-  def ask
-    sub_topics = if get_recommendation
-      get_recommendation.recommended_subtopic_ids
+  def solve
+    if (r = Recommendation.find_by_subtopic_id @subtopic_id)
+      r.recommended_subtopic_ids
     else
-      get_sub_topics.tap do |sub_topics|
-        Recommendation.create({
-          subtopic_id: @subtopic_id,
-          recommended_subtopic_ids: sub_topics.map { |s, l| [s, l.size] }
-        })
-      end
+      s = get_sub_topics
+      binding.pry # debug
+      create_recommendation s
+      s
     end
-
-    Kaminari.paginate_array(sub_topics).page(@page).per @per
   end
 
-  def get_recommendation
-    @recommendation ||= Recommendation.find_by_subtopic_id @subtopic_id
-  end
+  private
 
   def get_sub_topics
-    sub_topics = {}
-
-    users_also_listened.each do |user|
+    binding.pry # debug
+    User.who_listened_to(@subtopic_id).inject({}) do |sub_topics, user|
       user.listens.each do |listen|
         next if listen.subtopic_id == @subtopic_id
         sub_topics[listen.subtopic_id] ||= []
         sub_topics[listen.subtopic_id] << listen
       end
-    end
-    sub_topics.sort_by { |_, listens| listens.size }.reverse
+      binding.pry # debug
+      sub_topics
+    end.sort_by { |_, listens| listens.size }.reverse
   end
 
-  def users_also_listened
-    User.who_listened_to(@subtopic_id)
+  def create_recommendation(sub_topics)
+    Recommendation.create({
+      subtopic_id: @subtopic_id,
+      recommended_subtopic_ids: sub_topics.map { |sid, listens| [sid, listens.size] }
+    })
   end
 end

app/views/recommendations/index.html.haml

@@ -3,19 +3,17 @@
   = succeed ", you might also like..." do
     = link_to @sub_topic.name, sub_topic_path(@sub_topic)
 
-- sub_topics = @recommender.ask
-
 .well
   %table.table.table-striped.table-hover
     %thead
       %tr
         %th SubTopic
         %th Listens
     %tbody
-      - sub_topics.each do |subtopic_id, listens|
+      - @recommendations.each do |subtopic_id, listens|
         - sub_topic = SubTopic.find_by_subtopic_id subtopic_id
         %tr
           %td= link_to sub_topic.name, sub_topic
           %td= listens
 
-= paginate sub_topics
+= paginate @recommendations

lib/tasks/load.rake

@@ -59,7 +59,12 @@ namespace :load do
     subtopic_ids = SubTopic.pluck :subtopic_id
     puts "Creating #{subtopic_ids.size} recommendations..."
 
-    subtopic_ids.each { |subtopic_id| Recommender.new(subtopic_id).ask }
+    subtopic_ids.each_with_index do |subtopic_id, i|
+      subtopic = SubTopic.find_by_subtopic_id subtopic_id
+      puts "\tGenerating recommendations for #{subtopic.name}"
+
+      Recommender.new(subtopic_id).solve
+    end
     puts "\aDone."
   end
 end