Merge branch '4920-count-of-users-by-role-in-admin' into 'master'

Resolve "Count of users by role in admin"

Closes #4920

See merge request gitlab-org/gitlab-ee!4539

app/controllers/admin/dashboard_controller.rb

 class Admin::DashboardController < Admin::ApplicationController
+  prepend ::EE::Admin::DashboardController
+
   def index
     @projects = Project.order_id_desc.without_deleted.with_route.limit(10)
     @users = User.order_id_desc.limit(10)

app/models/project_authorization.rb

 class ProjectAuthorization < ActiveRecord::Base
+  prepend ::EE::ProjectAuthorization
+
   belongs_to :user
   belongs_to :project
 

app/views/admin/dashboard/index.html.haml

@@ -23,6 +23,9 @@
               %h3.text-center
                 Users:
                 = number_with_delimiter(User.count)
+            -# EE specific
+            .text-center
+              = link_to 'Users statistics', admin_dashboard_stats_path
             %hr
             = link_to 'New user', new_admin_user_path, class: "btn btn-new"
       .col-sm-4

changelogs/unreleased-ee/4920-count-of-users-by-role-in-admin.yml

+---
+title: Add users stats page for admin area with per role amount
+merge_request: 4539
+author:
+type: changed

config/routes/admin.rb

@@ -138,6 +138,8 @@ namespace :admin do
       get  :status
     end
   end
+
+  get '/dashboard/stats', to: 'dashboard#stats'
   ## EE-specific
 
   resources :labels

ee/app/controllers/ee/admin/dashboard_controller.rb

+# rubocop:disable Gitlab/ModuleWithInstanceVariables
+module EE
+  module Admin
+    module DashboardController
+      extend ActiveSupport::Concern
+
+      def stats
+        @admin_count = ::User.admins.count
+        @roles_count = ::ProjectAuthorization.roles_stats
+      end
+    end
+  end
+end

ee/app/models/ee/project_authorization.rb

+module EE
+  module ProjectAuthorization
+    extend ActiveSupport::Concern
+
+    module ClassMethods
+      # Get amout of users with highest role they have.
+      # If John is developer in one project but master in another he will be
+      # counted once as master. This is needed to count users who don't use
+      # functionality available to higher roles only.
+      #
+      # Example of result:
+      #  [{"kind"=>"guest", "amount"=>"4"},
+      #  {"kind"=>"reporter", "amount"=>"6"},
+      #  {"kind"=>"developer", "amount"=>"10"},
+      #  {"kind"=>"master", "amount"=>"9"},
+      #  {"kind"=>"owner", "amount"=>"1"}]
+      #
+      def roles_stats
+        connection.exec_query <<-EOF.strip_heredoc
+          SELECT CASE access_level
+            WHEN 10 THEN 'guest'
+            WHEN 20 THEN 'reporter'
+            WHEN 30 THEN 'developer'
+            WHEN 40 THEN 'master'
+            WHEN 50 THEN 'owner'
+            ELSE 'unknown' END
+            AS kind,
+            count(*) AS amount
+          FROM (
+              SELECT user_id, max(access_level) AS access_level
+              FROM #{table_name}
+              GROUP BY user_id
+          ) access_per_user
+          GROUP BY access_level
+          ORDER BY access_level ASC;
+        EOF
+      end
+    end
+  end
+end

ee/app/views/admin/dashboard/stats.html.haml

+- page_title 'Users statistics'
+
+%h3 Users statistics
+%table.table
+  %tr
+    %td Users total
+    %td
+      = User.count
+
+  - if @admin_count
+    %tr
+      %td Admin users
+      %td
+        = @admin_count
+
+  - if @roles_count
+    - @roles_count.each do |row|
+      %tr
+        %td
+          Users with highest role
+          %strong
+            = row['kind']
+        %td
+          = row['amount']

ee/spec/features/admin/admin_dashboard_spec.rb

+require 'spec_helper'
+
+describe 'Admin Dashboard' do
+  describe 'Users statistic' do
+    before do
+      project1 = create(:project_empty_repo)
+      project1.add_reporter(create(:user))
+
+      project2 = create(:project_empty_repo)
+      project2.add_developer(create(:user))
+
+      # Add same user as Reporter and Developer to different projects
+      # and expect it to be counted once for the stats
+      user = create(:user)
+      project1.add_reporter(user)
+      project2.add_developer(user)
+
+      sign_in(create(:admin))
+    end
+
+    describe 'Roles stats' do
+      it 'show correct amount of users per role' do
+        visit admin_dashboard_stats_path
+
+        expect(page).to have_content('Admin users 1')
+        expect(page).to have_content('Users with highest role developer 2')
+        expect(page).to have_content('Users with highest role reporter 1')
+      end
+    end
+  end
+end

ee/spec/models/ee/project_authorization_spec.rb

+require 'spec_helper'
+
+describe ProjectAuthorization do
+  describe '.roles_stats' do
+    before do
+      project1 = create(:project_empty_repo)
+      project1.add_reporter(create(:user))
+
+      project2 = create(:project_empty_repo)
+      project2.add_developer(create(:user))
+
+      # Add same user as Reporter and Developer to different projects
+      # and expect it to be counted once for the stats
+      user = create(:user)
+      project1.add_reporter(user)
+      project2.add_developer(user)
+    end
+
+    subject { described_class.roles_stats.to_a }
+
+    it do
+      expect(amount_for_kind('reporter')).to eq(1)
+      expect(amount_for_kind('developer')).to eq(2)
+      expect(amount_for_kind('master')).to eq(2)
+    end
+
+    def amount_for_kind(access_level)
+      subject.find do |row|
+        row['kind'] == access_level
+      end['amount'].to_i
+    end
+  end
+end