Show details for absorbed/absorbing organisations

app/models/organisation.rb

@@ -33,6 +33,7 @@ class Organisation < ApplicationRecord
   scope :search_by_name, ->(name) { where("name ILIKE ?", "%#{name}%") }
   scope :search_by, ->(param) { search_by_name(param) }
   scope :merged_during_open_collection_period, -> { where("merge_date >= ?", FormHandler.instance.start_date_of_earliest_open_for_editing_collection_period) }
+  scope :absorbed_on, ->(date) { where("merge_date = ?", date) }
 
   has_paper_trail
 
@@ -140,4 +141,19 @@ class Organisation < ApplicationRecord
   def duplicate_sales_logs_sets
     sales_logs.duplicate_sets.map { |array_str| array_str ? array_str.map(&:to_i) : [] }
   end
+
+  def recent_merge_date
+    if merge_date.present?
+      merge_date
+    elsif absorbed_organisations.any?
+      absorbed_organisations.map(&:merge_date).compact.max
+    end
+  end
+
+  def recently_absorbed_organisations
+    return unless absorbed_organisations.any?
+    return absorbed_organisations if recent_merge_date.blank?
+
+    absorbed_organisations.absorbed_on(recent_merge_date)
+  end
 end

app/views/organisations/_merged_organisation_details.html.erb

@@ -0,0 +1,32 @@
+<% if @organisation.absorbed_organisations.any? %>
+  <%= govuk_details(summary_text: "View all organisations that were merged into #{@organisation.name}") do %>
+    <p>Merge date: <%= @organisation.recent_merge_date&.to_formatted_s(:govuk_date) %></p>
+    <%= govuk_table do |table| %>
+      <%= table.head do |head| %>
+        <%= head.row do |row| %>
+          <% row.cell(header: true, text: "Organisation name", html_attributes: { scope: "col" }) %>
+          <% row.cell(header: true, text: "Organisation ID", html_attributes: { scope: "col" }) %>
+        <% end %>
+      <% end %>
+      <% @organisation.recently_absorbed_organisations&.each do |absorbed_org| %>
+        <%= table.body do |body| %>
+          <%= body.row do |row| %>
+            <% if current_user.support? %>
+              <% row.cell(text: simple_format(govuk_link_to(absorbed_org.name, organisation_path(absorbed_org)), { class: "govuk-!-font-weight-bold scheme-name-cell" }, wrapper_tag: "div")) %>
+            <% else %>
+              <% row.cell(text: absorbed_org.name) %>
+            <% end %>
+            <% row.cell(text: "ORG#{absorbed_org.id}") %>
+          <% end %>
+        <% end %>
+      <% end %>
+    <% end %>
+  <% end %>
+<% end %>
+<% if @organisation.absorbing_organisation.present? %>
+  <% if current_user.support? %>
+    <p><%= @organisation.name %> was merged into <%= govuk_link_to(@organisation.absorbing_organisation.name, organisation_path(@organisation.absorbing_organisation)) %><%= @organisation.merge_date ? " on #{@organisation.merge_date.to_formatted_s(:govuk_date)}" : "" %>.</p>
+  <% else %>
+    <p><%= @organisation.name %> was merged into <%= @organisation.absorbing_organisation.name %><%= @organisation.merge_date ? " on #{@organisation.merge_date.to_formatted_s(:govuk_date)}" : "" %>.</p>
+  <% end %>
+<% end %>

app/views/organisations/show.html.erb

@@ -39,6 +39,7 @@
     <% if FeatureToggle.merge_organisations_enabled? %>
       <p>To report a merge or update your organisation details, <%= govuk_link_to "contact the helpdesk", "https://dluhcdigital.atlassian.net/servicedesk/customer/portal/6/group/11" %>.</p>
     <% end %>
+    <%= render partial: "organisations/merged_organisation_details" %>
   </div>
 
   <div class="govuk-grid-column-one-third-from-desktop">

spec/requests/organisations_controller_spec.rb

@@ -279,6 +279,70 @@ RSpec.describe OrganisationsController, type: :request do
             expect(page).to have_content("To report a merge or update your organisation details, ")
             expect(page).to have_link("contact the helpdesk", href: "https://dluhcdigital.atlassian.net/servicedesk/customer/portal/6/group/11")
           end
+
+          it "does not display merge history if there is none" do
+            expect(page).not_to have_content("View all organisations that were merged into #{organisation.name}")
+          end
+
+          context "when the organisation has absorbed other organisations" do
+            let!(:absorbed_organisation) { create(:organisation, name: "First Absorbed Organisation") }
+            let!(:other_absorbed_organisation) { create(:organisation, name: "Other Absorbed Organisation") }
+            let!(:old_absorbed_organisation) { create(:organisation, name: "Old Absorbed Organisation") }
+
+            before do
+              absorbed_organisation.update!(merge_date: Time.zone.local(2023, 4, 3), absorbing_organisation: organisation)
+              other_absorbed_organisation.update!(merge_date: Time.zone.local(2023, 4, 3), absorbing_organisation: organisation)
+              old_absorbed_organisation.update!(merge_date: Time.zone.local(2023, 4, 2), absorbing_organisation: organisation)
+              get "/organisations/#{organisation.id}/details", headers:, params: {}
+            end
+
+            it "displays a list of absorbed organisations" do
+              expect(page).to have_content("View all organisations that were merged into #{organisation.name}")
+              expect(page).to have_content("Merge date: 3 April 2023")
+              expect(page).to have_content("First Absorbed Organisation")
+              expect(page).to have_content("Other Absorbed Organisation")
+              expect(page).not_to have_content("Old Absorbed Organisation")
+              expect(page).to have_content("ORG#{absorbed_organisation.id}")
+              expect(page).to have_content("ORG#{other_absorbed_organisation.id}")
+              expect(page).not_to have_content("ORG#{old_absorbed_organisation.id}")
+            end
+          end
+
+          context "when the organisation has absorbed other organisations without merge dates" do
+            let!(:absorbed_organisation) { create(:organisation, name: "First Absorbed Organisation") }
+            let!(:other_absorbed_organisation) { create(:organisation, name: "Other Absorbed Organisation") }
+
+            before do
+              absorbed_organisation.update!(merge_date: Time.zone.local(2023, 4, 3), absorbing_organisation: organisation)
+              other_absorbed_organisation.update!(merge_date: Time.zone.local(2023, 4, 3), absorbing_organisation: organisation)
+              get "/organisations/#{organisation.id}/details", headers:, params: {}
+            end
+
+            it "displays a list of absorbed organisations" do
+              expect(page).to have_content("View all organisations that were merged into #{organisation.name}")
+              expect(page).to have_content("Merge date:")
+              expect(page).to have_content("First Absorbed Organisation")
+              expect(page).to have_content("Other Absorbed Organisation")
+              expect(page).to have_content("ORG#{absorbed_organisation.id}")
+              expect(page).to have_content("ORG#{other_absorbed_organisation.id}")
+            end
+          end
+
+          context "when viewing absorbed organisation" do
+            let(:absorbing_organisation) { create(:organisation, name: "First Absorbing Organisation") }
+
+            context "and your organisation was absorbed" do
+              before do
+                organisation.update!(merge_date: Time.zone.local(2023, 4, 3), absorbing_organisation:)
+                get "/organisations/#{organisation.id}/details", headers:, params: {}
+              end
+
+              it "displays the organisation merge details" do
+                expect(response).not_to have_http_status(:not_found)
+                expect(page).to have_content("#{organisation.name} was merged into First Absorbing Organisation on 3 April 2023.")
+              end
+            end
+          end
         end
 
         context "with organisation that are not in scope for the user, i.e. that they do not belong to" do