handle movie not found on Wikipedia

app/controllers/movies_controller.rb

@@ -92,8 +92,14 @@ def remove_from_watched
   end
 
   def wikipedia
-    @movie.get_wikipedia_title unless @movie.wikipedia_title
-    redirect_to @movie.wikipedia_url
+    @movie.update_wikipedia_url! unless @movie.wikipedia_url.present?
+
+    if @movie.wikipedia_url.present?
+      redirect_to @movie.wikipedia_url, status: 301
+    else
+      @message = "Can't find this movie on Wikipedia."
+      render 'shared/not_found', :status => 404
+    end
   end
 
   def change_plot_field

app/models/movie.rb

@@ -242,10 +242,9 @@ def wikipedia_title=(str)
   def wikipedia_url
     WIKIPEDIA_PREFIX + wikipedia_title.tr(' ', '_') if wikipedia_title
   end
-  
-  def get_wikipedia_title
+
+  def update_wikipedia_url!
     self.wikipedia_title = Wikipedia.find_title("#{self.title} #{self.year}")
     self.save
-    self.wikipedia_title
   end
 end

spec/models/movie_spec.rb

@@ -216,7 +216,7 @@ def create(attributes)
         )
 
       movie = build title: 'Misery', year: 1990
-      movie.get_wikipedia_title.should == 'Misery (1990 film)'
+      movie.update_wikipedia_url!
       movie.wikipedia_url.should == 'http://en.wikipedia.org/wiki/Misery_(1990_film)'
     end
   end

spec/requests/movies_spec.rb

@@ -0,0 +1,43 @@
+require 'spec_helper'
+
+describe "Movies" do
+  describe "GET /[movie]/wikipedia" do
+    before do
+      @movie = Movie.create title: 'Misery', year: 1990
+    end
+
+    it "fetches wikipedia URL from its API" do
+      stub_request(:get, 'en.wikipedia.org/w/api.php?format=json&action=query&list=search&srsearch=Misery%201990').
+        to_return(
+          body: {query: {search:[{title: 'Misery (1990 film)'}]}}.to_json,
+          status: 200,
+          headers: {'content-type' => 'application/json'}
+        )
+
+      get wikipedia_movie_path(@movie)
+      response.status.should be(301)
+      response.should redirect_to 'http://en.wikipedia.org/wiki/Misery_(1990_film)'
+    end
+
+    it "handles movie not found" do
+      stub_request(:get, 'en.wikipedia.org/w/api.php?format=json&action=query&list=search&srsearch=Misery%201990').
+        to_return(
+          body: {query: {search:[]}}.to_json,
+          status: 200,
+          headers: {'content-type' => 'application/json'}
+        )
+
+      get wikipedia_movie_path(@movie)
+      response.status.should be(404)
+    end
+
+    it "uses stored wikipedia URL" do
+      @movie.wikipedia_title = 'http://en.wikipedia.org/wiki/Misery_(1990_film)'
+      @movie.save
+
+      get wikipedia_movie_path(@movie)
+      response.status.should be(301)
+      response.should redirect_to @movie.wikipedia_url
+    end
+  end
+end