Add a simple summary export

app/controllers/home_controller.rb

@@ -11,4 +11,8 @@ class HomeController < ApplicationController
   def export
     @talk_preferences = TalkPreference.this_years.eager_load(:selected_talks)
   end
+
+  def summary
+    @summary = Summary.new params[:summary]
+  end
 end

app/models/summary.rb

@@ -0,0 +1,23 @@
+class Summary
+  def initialize(params = {})
+    @talk_id, @other_talk_ids = params[:talk_id], params[:other_talk_ids]
+    @votes_count = SelectedTalk.where(talk_id: @talk_id).count
+    @all_votes_count = TalkPreference.joins(:selected_talks).where(selected_talks: {talk_id: @other_talk_ids << @talk_id}).count
+  end
+
+  def summary
+    {
+     talk_id: @talk_id,
+     votes: @votes_count,
+     all_votes: @all_votes_count,
+     per_cent: Rational(@votes_count, @all_votes_count).to_f,
+     conflicts: conflicts
+    }
+  end
+
+  def conflicts
+    @other_talk_ids.map do |right|
+      [right, ConflictCoefficient.new(@talk_id, right).conflicts]
+    end.to_h
+  end
+end

app/views/home/summary.json.jbuilder

@@ -0,0 +1 @@
+json.merge! @summary.summary

config/routes.rb

@@ -3,6 +3,11 @@ Rails.application.routes.draw do
   root to: 'home#index'
   get 'ratings' => 'home#ratings'
   get 'export' => 'home#export'
-  resources :conflicts
+  get 'summary' => 'home#summary'
+  resources :conflicts do
+    collection do
+      get 'pivot'
+    end
+  end
   # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
 end