From 0fbe3243c41090d73c3ac4585dcddf5ce011fad7 Mon Sep 17 00:00:00 2001
From: Petko Bordjukov <bordjukov@gmail.com>
Date: Thu, 15 Oct 2015 02:01:03 +0300
Subject: [PATCH] Conflict coefficients

---
 app/controllers/home_controller.rb           |  4 ++++
 app/models/conflict_coefficient.rb           | 25 ++++++++++++++++++++
 app/models/talk_preference.rb                |  4 ++++
 app/views/home/_conflict_coefficient.csv.erb |  1 +
 app/views/home/conflicts.csv.erb             |  3 +++
 config/routes.rb                             |  1 +
 6 files changed, 38 insertions(+)
 create mode 100644 app/models/conflict_coefficient.rb
 create mode 100644 app/views/home/_conflict_coefficient.csv.erb
 create mode 100644 app/views/home/conflicts.csv.erb

diff --git a/app/controllers/home_controller.rb b/app/controllers/home_controller.rb
index 1485932..ac1cfab 100644
--- a/app/controllers/home_controller.rb
+++ b/app/controllers/home_controller.rb
@@ -11,4 +11,8 @@ class HomeController < ApplicationController
     @talks = Talk.all
     @talk_preferences = TalkPreference.all
   end
+
+  def conflicts
+    @conflict_coefficients = ConflictCoefficient.all
+  end
 end
diff --git a/app/models/conflict_coefficient.rb b/app/models/conflict_coefficient.rb
new file mode 100644
index 0000000..cb6df0d
--- /dev/null
+++ b/app/models/conflict_coefficient.rb
@@ -0,0 +1,25 @@
+class ConflictCoefficient
+  attr_reader :left, :right, :conflicts
+
+  def self.all
+    talk_combinations = Talk.all.map(&:id).combination(2)
+    talk_preferences = TalkPreference.all
+    talk_preferences_count = TalkPreference.count
+
+    talk_combinations.map do |talks|
+      conflicts = talk_preferences.select do |talk_preference|
+        talk_preference.include_all? talks
+      end.count
+
+      ConflictCoefficient.new talks.first, talks.last, conflicts, talk_preferences_count
+    end
+  end
+
+  def initialize(left, right, conflicts, total_votes)
+    @left, @right, @conflicts, @total_votes = left, right, conflicts, total_votes
+  end
+
+  def per_cent
+    Rational(100 * @conflicts, @total_votes).to_f
+  end
+end
diff --git a/app/models/talk_preference.rb b/app/models/talk_preference.rb
index 523424c..fe68f93 100644
--- a/app/models/talk_preference.rb
+++ b/app/models/talk_preference.rb
@@ -9,6 +9,10 @@ class TalkPreference < ActiveRecord::Base
     talks.include? id.to_s
   end
 
+  def include_all?(ids)
+    ids.all? { |id| include? id }
+  end
+
   private
 
   def assign_new_unique_id
diff --git a/app/views/home/_conflict_coefficient.csv.erb b/app/views/home/_conflict_coefficient.csv.erb
new file mode 100644
index 0000000..ea34f37
--- /dev/null
+++ b/app/views/home/_conflict_coefficient.csv.erb
@@ -0,0 +1 @@
+<%= CSV.generate_line([conflict_coefficient.left, conflict_coefficient.right, conflict_coefficient.conflicts, conflict_coefficient.per_cent]).html_safe -%>
diff --git a/app/views/home/conflicts.csv.erb b/app/views/home/conflicts.csv.erb
new file mode 100644
index 0000000..8f3c4ad
--- /dev/null
+++ b/app/views/home/conflicts.csv.erb
@@ -0,0 +1,3 @@
+<%- headers = ['left', 'right', 'conflicts', '%'] -%>
+<%= CSV.generate_line headers -%>
+<%= render partial: 'conflict_coefficient', collection: @conflict_coefficients %>
diff --git a/config/routes.rb b/config/routes.rb
index 1a04cd5..8fbcb1c 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -3,4 +3,5 @@ Rails.application.routes.draw do
   root to: 'home#index'
   get 'ratings' => 'home#ratings'
   get 'export' => 'home#export'
+  get 'conflicts' => 'home#conflicts'
 end