Add GET /api/choices/new and associated bits

app/controllers/api/choices_controller.rb

@@ -1,2 +1,14 @@
 class Api::ChoicesController < ApplicationController
+
+	def new
+		if !params[:topic]
+			render :json => {:error => 'no topic supplied'}, :status => :unprocessable_entity
+		else
+			render :json => Choice.create_randomly(:topic => params[:topic]).for_api
+		end
+	end
+
+	def update
+	end
+
 end

app/models/choice.rb

@@ -3,4 +3,28 @@ class Choice < ActiveRecord::Base
   belongs_to :option_a, :class_name => 'Tweet'
   belongs_to :option_b, :class_name => 'Tweet'
   # attr_accessible :title, :body
+
+  def self.create_randomly(params)
+  	topic = Topic.where(:title => params[:topic]).first!
+  	real = Tweet.where(:topic_id => topic, :fake => false).order("RANDOM()").first
+  	fake = Tweet.where(:topic_id => topic, :fake => true).order("RANDOM()").first
+
+  	a_b = [real,fake].shuffle
+  	c = Choice.new
+  	c.topic = topic
+  	c.option_a = a_b[0]
+  	c.option_b = a_b[1]
+  	c.save!
+  	c
+  end
+
+  def for_api
+  	{
+  	  :id => self.id,
+  	  :topic => self.topic.title,
+  		:a => self.option_a.text,
+  		:b => self.option_b.text
+  	}
+  end
+
 end

app/models/topic.rb

@@ -3,4 +3,6 @@ class Topic < ActiveRecord::Base
   has_many :tweets
   has_many :markov_chains
   has_many :choices
+
+  validates_uniqueness_of :title
 end

app/models/tweet.rb

@@ -1,4 +1,4 @@
 class Tweet < ActiveRecord::Base
   belongs_to :topic
-  attr_accessible :fake, :text
+  attr_accessible :fake, :text  
 end