Add execution environment statistics

app/controllers/execution_environments_controller.rb

@@ -2,7 +2,7 @@ class ExecutionEnvironmentsController < ApplicationController
   include CommonBehavior
 
   before_action :set_docker_images, only: [:create, :edit, :new, :update]
-  before_action :set_execution_environment, only: MEMBER_ACTIONS + [:execute_command, :shell]
+  before_action :set_execution_environment, only: MEMBER_ACTIONS + [:execute_command, :shell, :statistics]
   before_action :set_testing_framework_adapters, only: [:create, :edit, :new, :update]
 
   def authorize!
@@ -28,6 +28,9 @@ class ExecutionEnvironmentsController < ApplicationController
     render(json: @docker_client.execute_arbitrary_command(params[:command]))
   end
 
+  def statistics
+  end
+
   def execution_environment_params
     params[:execution_environment].permit(:docker_image, :exposed_ports, :editor_mode, :file_extension, :file_type_id, :help, :indent_size, :memory_limit, :name, :network_enabled, :permitted_execution_time, :pool_size, :run_command, :test_command, :testing_framework).merge(user_id: current_user.id, user_type: current_user.class.name)
   end

app/policies/execution_environment_policy.rb

@@ -4,7 +4,7 @@ class ExecutionEnvironmentPolicy < AdminOrAuthorPolicy
   end
   private :author?
 
-  [:execute_command?, :shell?].each do |action|
+  [:execute_command?, :shell?, :statistics?].each do |action|
     define_method(action) { admin? || author? }
   end
 end

app/views/execution_environments/index.html.slim

@@ -9,7 +9,7 @@ h1 = ExecutionEnvironment.model_name.human(count: 2)
         th = t('activerecord.attributes.execution_environment.memory_limit')
         th = t('activerecord.attributes.execution_environment.network_enabled')
         th = t('activerecord.attributes.execution_environment.permitted_execution_time')
-        th colspan=4 = t('shared.actions')
+        th colspan=5 = t('shared.actions')
         th colspan=2 = t('shared.resources')
     tbody
       - @execution_environments.each do |execution_environment|
@@ -23,6 +23,7 @@ h1 = ExecutionEnvironment.model_name.human(count: 2)
           td = link_to(t('shared.edit'), edit_execution_environment_path(execution_environment))
           td = link_to(t('shared.destroy'), execution_environment, data: {confirm: t('shared.confirm_destroy')}, method: :delete)
           td = link_to(t('.shell'), shell_execution_environment_path(execution_environment))
+          td = link_to(t('shared.statistics'), statistics_execution_environment_path(execution_environment))
           td = link_to(t('activerecord.models.error.other'), execution_environment_errors_path(execution_environment.id))
           td = link_to(t('activerecord.models.hint.other'), execution_environment_hints_path(execution_environment.id))
 

app/views/execution_environments/statistics.html.slim

@@ -0,0 +1,23 @@
+h1 = @execution_environment
+
+.table-responsive
+  table.table
+    thead
+      tr
+        - ['.exercise', '.score', '.runs', '.worktime'].each do |title|
+          th.header = t(title)
+    tbody
+      - @execution_environment.exercises.each do |exercise|
+        tr
+          - submissions = exercise.submissions
+          td = exercise.title
+          td = submissions.average(:score)
+          td = submissions.count()
+          - minima = submissions.group(:user_id).minimum(:created_at)
+          - maxima = submissions.group(:user_id).maximum(:created_at)
+          - result = 0
+          - results = {}
+          - maxima.each {|key, value| results[key] = value - minima[key]}
+          - results.values.map {|value| result += value}
+          - result /= results.size if results.size > 0
+          td = distance_of_time_in_words(result)