new feature: movie recommendations

The recommendation engine is an external app to which we talk over HTTP.
The resulting movie IDs are filtered down to:

 - movies that you haven't ignored (deleted from recommendations);
 - movies that you haven't watched yet;
 - movies that you haven't added in your to-watch list.

Recommendations are cached for 24 hours.

Mad props to @norbert for making the recommendation engine!

Gemfile

@@ -30,6 +30,8 @@ gem 'rails-behaviors'
 gem 'omniauth-twitter'
 gem 'omniauth-facebook'
 
+gem 'fickle-ruby', :git => 'git://github.com/norbert/fickle-ruby.git', :branch => 'master'
+
 group :extras do
   gem 'nokogiri', '~> 1.4.1'
   gem 'nibbler', '~> 1.3' #, :path => '/Users/mislav/Projects/nibbler'

Gemfile.lock

@@ -1,3 +1,12 @@
+GIT
+  remote: git://github.com/norbert/fickle-ruby.git
+  revision: 55020ed484a4b95b3e057c122ad41706b38f6305
+  branch: master
+  specs:
+    fickle-ruby (0.0.1)
+      faraday
+      multi_json
+
 GEM
   remote: https://rubygems.org/
   specs:
@@ -69,7 +78,7 @@ GEM
     eventmachine (0.12.10)
     execjs (1.3.0)
       multi_json (~> 1.0)
-    faraday (0.8.0.rc2)
+    faraday (0.8.7)
       multipart-post (~> 1.1)
     faraday_middleware (0.8.4)
       faraday (>= 0.7.4, < 0.9)
@@ -103,8 +112,8 @@ GEM
       daemons (>= 1.0.3)
       fastthread (>= 1.0.1)
       gem_plugin (>= 0.2.3)
-    multi_json (1.6.1)
-    multipart-post (1.1.4)
+    multi_json (1.7.7)
+    multipart-post (1.2.0)
     never-forget (0.1.0)
       activesupport
       erubis
@@ -233,6 +242,7 @@ DEPENDENCIES
   escape_utils
   faraday (~> 0.8.0.rc)
   faraday_middleware
+  fickle-ruby!
   launchy
   mingo (>= 0.3.0)
   mongo-rails-instrumentation

app/assets/javascripts/actions.coffee

@@ -21,3 +21,11 @@ replaceActions = (element, content) ->
   element.replaceWith(content)
   preserve = element.find('.js-preserve')
   parent.find('.actions').eq(0).prepend preserve
+
+$(document).on 'ajaxSuccess', '.movie-recommendations .ignore', (e, xhr) ->
+  movie = $(this).closest('.movie')
+  container = movie.parent()
+  others = movie.siblings('.movie')
+  movie.remove()
+  if others.size is 0
+    container.find('.blank').removeClass('blank')

app/assets/stylesheets/movie.scss

@@ -86,7 +86,7 @@ ol.movies { clear:left; padding-left:0;
 
       + a.revert { padding:0 5px; }
     }
-    a.revert { 
+    a.revert, a.ignore {
       color:#ccc; text-decoration:none;
 
       &:hover { color:firebrick; }
@@ -255,3 +255,12 @@ ol.movies { clear:left; padding-left:0;
     .actions { margin-top:7px; }
   }
 }
+
+.movie-recommendations {
+  .movie {
+    padding-bottom: 1.3em;
+    border-bottom: 1px solid #e8e8e8;
+    &:last-child { border-bottom: none }
+  }
+  .blank { display: none }
+}

app/controllers/movies_controller.rb

@@ -107,6 +107,12 @@ def remove_from_watched
     current_user.watched.delete @movie
     ajax_actions_or_back
   end
+
+  def ignore_recommendation
+    recommendations = Recommendations.new(current_user)
+    recommendations.ignore_movie(@movie)
+    ajax_actions_or_back { head :ok }
+  end
 
   def wikipedia
     @movie.update_wikipedia_url! unless @movie.wikipedia_url.present?
@@ -156,8 +162,12 @@ def redirect_to_permalink?(movie)
 
   def ajax_actions_or_back
     if request.xhr?
-      response.content_type = Mime::HTML
-      render :partial => 'actions', :locals => {:movie => @movie}
+      if block_given?
+        yield
+      else
+        response.content_type = Mime::HTML
+        render :partial => 'actions', :locals => {:movie => @movie}
+      end
     else
       redirect_to :back
     end

app/controllers/users_controller.rb

@@ -2,8 +2,8 @@
 
 class UsersController < ApplicationController
 
-  before_filter :load_user, :only => [:show, :to_watch, :liked]
-  before_filter :login_required, :only => [:following]
+  before_filter :load_user, :only => [:show, :to_watch, :liked, :recommendations]
+  before_filter :login_required, :only => [:following, :recommendations]
 
   def index
     @users = User.find({}, :sort => ['_id', -1]).to_a
@@ -48,7 +48,8 @@ def watched_index
 
   def show
     @movies = @user.watched(max_id: params[:max_id]).page(params[:page])
-    ajax_pagination if stale? etag: session_cache_key(@movies)
+    @recommended = Recommendations.new(@user)
+    ajax_pagination if my_page? || stale?(etag: session_cache_key(@movies))
   end
 
   def liked
@@ -58,7 +59,8 @@ def liked
 
   def to_watch
     @movies = @user.to_watch(max_id: params[:max_id]).page(params[:page])
-    ajax_pagination if stale? etag: session_cache_key(@movies)
+    @recommended = Recommendations.new(@user)
+    ajax_pagination if my_page? || stale?(etag: session_cache_key(@movies))
   end
 
   def timeline
@@ -67,6 +69,13 @@ def timeline
     ajax_pagination
   end
 
+  def recommendations
+    @recommended = Recommendations.new(@user)
+    unless Movies.offline?
+      @recommended.movies.map(&:ensure_extended_info)
+    end
+  end
+
   def following
   end
 

app/helpers/users_helper.rb

@@ -11,6 +11,14 @@ def user_name(user)
     user.name.presence || user.username
   end
 
+  def user_friendly_name(user)
+    if user.name.present?
+      user.name.split(' ', 2)[0]
+    else
+      user.username
+    end
+  end
+
   def screen_name(user)
     # some usernames are numeric Facebook IDs, don't show them
     (user.username =~ /\D/ or user.name.blank?) ? user.username : user.name

app/models/recommendations.rb

@@ -0,0 +1,61 @@
+require 'fickle'
+require 'forwardable'
+
+Recommendations = Struct.new(:user) do
+  extend Forwardable
+  def_delegators :movies, :any?, :empty?, :size
+
+  def load_movies
+    Movie.find(recommended_movie_ids)
+  end
+
+  def recommended_movie_ids
+    @movie_ids ||= fetch_recommendations[0].map {|item| BSON::ObjectId[item[0]] }
+  end
+
+  def movies
+    @movies ||= load_movies.reject { |movie|
+      ignored_ids.include?(movie.id) ||
+        to_watch_ids.include?(movie.id) ||
+        watched_ids.include?(movie.id)
+    }
+  end
+
+  def ignored_ids
+    user.ignored_recommendations
+  end
+
+  def ignore_movie(movie)
+    user.ignored_recommendations << movie.id
+  end
+
+  def watched_ids
+    @watched ||= user.watched(filter_association).
+      link_documents.map {|doc| doc['movie_id'] }
+  end
+
+  def to_watch_ids
+    @to_watch ||= user.to_watch(filter_association).
+      link_documents.map {|doc| doc['movie_id'] }
+  end
+
+  def filter_association
+    { :movie_id => { '$in' => recommended_movie_ids } }
+  end
+
+  # response: [ [ [id, rating], [id, rating], ... ] ]
+  def fetch_recommendations
+    Rails.cache.fetch("recommendations/#{user.id}", expires_in: 1.day) do
+      fickle = Fickle::Client.new(fickle_url, fickle_key)
+      fickle.recommend([user.id.to_s])
+    end
+  end
+
+  def fickle_url
+    Movies::Application.config.fickle.url
+  end
+
+  def fickle_key
+    Movies::Application.config.fickle.api_key
+  end
+end

app/models/user.rb

@@ -10,7 +10,9 @@ class User < Mingo
 
   include ToWatch
   include Watched
-
+
+  property :ignored_recommendations, :type => :set
+
   def username=(value)
     self['username'] = self.class.generate_username(value)
   end

app/views/movies/_full_movie.html.erb

@@ -0,0 +1,46 @@
+<%= movie_poster(movie, :medium) %>
+
+<header>
+  <%= render 'movies/title', :movie => movie %>
+
+  <% if movie.directors.present? %>
+    <p class="directors">by <strong><%= movie.directors.map { |name|
+      link_to(name, director_path(name))
+    }.to_sentence.html_safe %></strong></p>
+  <% end %>
+
+  <% if movie.countries.present? %>
+    <p class="countries">in <%= movie.countries.to_sentence %></p>
+  <% end %>
+
+  <%= movie_runtime(movie) %>
+</header>
+
+<% if movie.chosen_plot.present? %>
+<p class="plot"><%= movie_plot movie %></p>
+<% end %>
+
+<% if elsewhere = movie_elsewhere(movie).presence %>
+  <p class="elsewhere">
+    Elsewhere:
+    <%= raw elsewhere.map { |label, url, title|
+      link_to(label, url, title: title)
+    }.join(separator) %>
+  </p>
+<% end %>
+
+<%= movie_actions(movie) %>
+
+<% if logged_in? and (stats = current_user.friends_who_watched(movie)).present? %>
+  <div class="friends">
+    <span class=label>Social</span>
+    <% for rating, label in [ [true, 'liked'], [nil, 'meh'], [false, 'disliked'] ] -%>
+      <% people = stats.people_who_rated(rating) -%>
+      <% names = people.map {|p| screen_name(p) } -%>
+      <span class=<%= label %> rel=tooltip title="<%= label %>: <%= people.any?? names.to_sentence : 'none' %>">
+        <%= people.size %>
+        <% if rating == true %>♥<% end %>
+      </span>
+    <% end -%>
+  </div>
+<% end %>

app/views/movies/show.html.erb

@@ -13,54 +13,9 @@
 <% end -%>
 
 <article class="movie">
-
-  <%= movie_poster(@movie, :medium) %>
-
-  <header>
-    <%= render 'title', :movie => @movie %>
-    
-    <% if @movie.directors.present? %>
-      <p class="directors">by <strong><%= @movie.directors.map { |name|
-        link_to(name, director_path(name))
-      }.to_sentence.html_safe %></strong></p>
-    <% end %>
 
-    <% if @movie.countries.present? %>
-      <p class="countries">in <%= @movie.countries.to_sentence %></p>
-    <% end %>
+  <%= render 'full_movie', movie: @movie %>
 
-    <%= movie_runtime(@movie) %>
-  </header>
-
-  <% if @movie.chosen_plot.present? %>
-  <p class="plot"><%= movie_plot @movie %></p>
-  <% end %>
-  
-  <% if elsewhere = movie_elsewhere(@movie).presence %>
-    <p class="elsewhere">
-      Elsewhere:
-      <%= raw elsewhere.map { |label, url, title|
-        link_to(label, url, title: title)
-      }.join(separator) %>
-    </p>
-  <% end %>
-  
-  <%= movie_actions(@movie) %>
-
-  <% if logged_in? and (stats = current_user.friends_who_watched(@movie)).present? %>
-    <div class="friends">
-      <span class=label>Social</span>
-      <% for rating, label in [ [true, 'liked'], [nil, 'meh'], [false, 'disliked'] ] -%>
-        <% people = stats.people_who_rated(rating) -%>
-        <% names = people.map {|p| screen_name(p) } -%>
-        <span class=<%= label %> rel=tooltip title="<%= label %>: <%= people.any?? names.to_sentence : 'none' %>">
-          <%= people.size %>
-          <% if rating == true %>♥<% end %>
-        </span>
-      <% end -%>
-    </div>
-  <% end %>
-  
     <% if admin? %>
       <aside class="admin">
         <ul>

app/views/users/_recommendation_notice.html.erb

@@ -0,0 +1,7 @@
+<% if my_page? && @recommended && @recommended.any? %>
+  <p class="flash notice">
+    Hey <%= user_friendly_name(@user) %>, we've got
+    <%= link_to pluralize(@recommended.size, 'recommendation'), movie_recommendations_path(@user) %>
+    for you!
+  </p>
+<% end %>

app/views/users/recommendations.html.erb

@@ -0,0 +1,24 @@
+<% body_class 'movie-show movie-recommendations' %>
+
+<article>
+  <header>
+    <h1>Recommended for you</h1>
+  </header>
+
+  <% for movie in @recommended.movies %>
+    <article class="movie">
+      <%= render 'movies/full_movie', movie: movie %>
+
+      <p class=actions>
+        <%= link_to "× Ignore this recommendation", [:ignore_recommendation, movie], :remote => true, :method => :put, :class => 'ignore' %>
+      </p>
+    </article>
+  <% end %>
+
+  <p<%= @recommended.any?? ' class=blank' : '' %>>
+    No new recommendations as this time. Check back some other day!
+    <br>
+    See what the <%= link_to "people you follow are watching", timeline_path %>
+  </p>
+
+</article>

app/views/users/show.html.erb

@@ -40,6 +40,8 @@
       </nav>
     </header>
 
+    <%= render 'recommendation_notice' %>
+
     <%= render 'movies/paginated', :movies => @movies %>
 
   <% elsif my_page? and (forced_blank_slate? or @user.to_watch.empty?) %>