Statistics on top of Registrations#index

app/controllers/admin/registrations_controller.rb

@@ -9,6 +9,10 @@ module Admin
       @pdf_filename = "#{@conference.title}.pdf"
       @registrations = @conference.registrations.includes(:user).order('registrations.created_at ASC')
       @attended = @conference.registrations.where('attended = ?', true).count
+
+      @new_reg = @conference.registrations.where('created_at > ?', current_user.last_sign_in_at).count
+      @registration_distribution = @conference.registration_distribution
+      @affiliation_distribution = @conference.affiliation_distribution
     end
 
     def edit; end

app/models/conference.rb

@@ -325,11 +325,58 @@ class Conference < ActiveRecord::Base
   # * +hash+ -> hash
   def scheduled_event_distribution
     confirmed_events = program.events.where(state: 'confirmed')
-    scheduled_value =  { 'value' => confirmed_events.where('start_time IS NOT NULL').count, 'color' => 'green' }
+    scheduled_value =  { 'value' => confirmed_events.where.not(start_time: nil).count, 'color' => 'green' }
-    unscheduled_value =  { 'value' => confirmed_events.where('start_time IS NULL').count, 'color' => 'red' }
+    unscheduled_value =  { 'value' => confirmed_events.where(start_time: nil).count, 'color' => 'red' }
     { 'Scheduled' => scheduled_value, 'Unscheduled' => unscheduled_value }
   end
 
+  ##
+  # Returns a hash with Registration attended vs. Registration not attended
+  # { "Attended" => { value: number of registration attended, color: color },
+  #   "Not attended" => { value: number of registration not attended, color: color }
+  #
+  # ====Returns
+  # * +hash+ -> hash
+  def registration_distribution
+    reg = registrations.includes(:user)
+    attended_value =  { 'value' => reg.where(attended: true).count, 'color' => 'magenta' }
+    not_attended_value =  { 'value' => reg.where.not(attended: true).count, 'color' => 'blue' }
+    { 'Attended' => attended_value, 'Not attended' => not_attended_value }
+  end
+
+  ##
+  # Returns a hash with affiliation =>
+  # {value: count of registration whose user has that affilation, color: color}
+  # In case that the affiliation is blank, it groups them in None and
+  # if the number of persons that have an affiliation are less than the 2% of
+  # the total number of registered people, they are grouped in others.
+  #
+  # ====Returns
+  # * +hash+ -> hash
+  def affiliation_distribution
+    counted_affiliations = registrations.joins(:user).group(:affiliation).count
+    result = {}
+    i=1
+    others = 0
+    none = 0
+    counted_affiliations.each do |key, value|
+      if value < 0.02 * registrations.length
+        others += value
+      elsif key.blank?
+        none += value
+      else
+        result[key.capitalize] = { 'value' => value, 'color' => next_color(i) }
+        i += 1
+      end
+    end
+    if others > 0
+      result['Others'] = { 'value' => others, 'color' => next_color(i) }
+      i += 1
+    end
+    result['None'] = { 'value' => none, 'color' => next_color(i) } if none > 0
+    result
+  end
+
   ##
   # Returns a hash with user distribution => {value: count of user state, color: color}
   # active: signed in during the last 3 months
@@ -550,6 +597,16 @@ class Conference < ActiveRecord::Base
 
   private
 
+  # Returns a different html colour for every i. We make use of big prime numbers
+  # to avoid repetition and to make consecutive colors clearly different.
+  def next_color(i)
+    color = '#000000'
+    color[1..2] = ((i*113)%239 + 16).to_s(16)
+    color[3..4] = ((i*67)%239 + 16).to_s(16)
+    color[5..6] = ((i*151)%239 + 16).to_s(16)
+    color
+  end
+
   after_create do
     self.create_contact
     self.create_program

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

@@ -11,6 +11,26 @@
             = link_to 'Export XLS', {format: :xlsx}, class: 'btn btn-success'
       %p.text-muted
         All the people who registered to your event
+.row
+  .col-sm-4.col-xs-4
+    .dashbox.text-center
+      %span.fa.fa-user.fa-lg
+      %span.fa.fa-lg
+        = @registrations.length
+      %p
+        %small
+          #{'Registration'.pluralize(@registrations.length)}
+        - if @new_reg
+          %span.label.label-success{title: "+#{@new_reg} since you last logged in!"}
+            +
+            = @new_reg
+  .col-md-4
+    = render partial: 'admin/conference/doughnut_chart', locals: {title: 'Affiliation', data: @affiliation_distribution}
+  - unless @conference.pending?
+    .col-md-4
+      = render partial: 'admin/conference/doughnut_chart', locals: {title: 'Attended registrations', data: @registration_distribution}
+.row
+  .col-md-12
     %table.table.table-hover.datatable#registrations
       %thead
         %tr