Scaffold exercise collection statistics

app/controllers/exercise_collections_controller.rb

@@ -1,7 +1,8 @@
 class ExerciseCollectionsController < ApplicationController
   include CommonBehavior
+  include TimeHelper
 
-  before_action :set_exercise_collection, only: [:show, :edit, :update, :destroy]
+  before_action :set_exercise_collection, only: [:show, :edit, :update, :destroy, :statistics]
 
   def index
     @exercise_collections = ExerciseCollection.all.paginate(:page => params[:page])
@@ -34,6 +35,14 @@ class ExerciseCollectionsController < ApplicationController
     update_and_respond(object: @exercise_collection, params: exercise_collection_params)
   end
 
+  def statistics
+    @working_times = {}
+    @exercise_collection.exercises.each do |exercise|
+      @working_times[exercise.id] = time_to_f exercise.average_working_time
+    end
+    @average = @working_times.values.reduce(:+) / @working_times.size
+  end
+
   private
 
   def set_exercise_collection

app/policies/exercise_collection_policy.rb

@@ -1,3 +1,7 @@
 class ExerciseCollectionPolicy < AdminOnlyPolicy
 
+  def statistics?
+    admin?
+  end
+
 end

app/views/exercise_collections/index.html.slim

@@ -8,7 +8,7 @@ h1 = ExerciseCollection.model_name.human(count: 2)
         th = t('activerecord.attributes.exercise_collections.name')
         th = t('activerecord.attributes.exercise_collections.updated_at')
         th = t('activerecord.attributes.exercise_collections.exercises')
-        th colspan=3 = t('shared.actions')
+        th colspan=4 = t('shared.actions')
     tbody
       - @exercise_collections.each do |collection|
         tr
@@ -18,6 +18,7 @@ h1 = ExerciseCollection.model_name.human(count: 2)
           td = collection.exercises.size
           td = link_to(t('shared.show'), collection)
           td = link_to(t('shared.edit'), edit_exercise_collection_path(collection))
+          td = link_to(t('shared.statistics'), statistics_exercise_collection_path(collection))
           td = link_to(t('shared.destroy'), collection, data: {confirm: t('shared.confirm_destroy')}, method: :delete)
 
 = render('shared/pagination', collection: @exercise_collections)

app/views/exercise_collections/statistics.html.slim

@@ -0,0 +1,6 @@
+h1 = @exercise_collection
+
+= row(label: 'exercise_collections.name', value: @exercise_collection.name)
+= row(label: 'exercise_collections.updated_at', value: @exercise_collection.updated_at)
+= row(label: 'exercise_collections.exercises', value: @exercise_collection.exercises.count)
+= row(label: 'exercises.statistics.average_worktime', value: @average.round(3).to_s + 's')

config/routes.rb

@@ -84,7 +84,11 @@ Rails.application.routes.draw do
     end
   end
 
-  resources :exercise_collections
+  resources :exercise_collections do
+    member do
+      get :statistics
+    end
+  end
 
   resources :proxy_exercises do
     member do