Implement organisation name change feature with history tracking

app/controllers/organisation_name_changes_controller.rb

@@ -0,0 +1,35 @@
+class OrganisationNameChangesController < ApplicationController
+  before_action :set_organisation, only: %i[create change_name]
+  before_action :set_previous_name_changes, only: %i[create change_name]
+
+  def create
+    @organisation_name_change = @organisation.organisation_name_changes.new(organisation_name_change_params)
+    @organisation_name_change.change_type = "User change"
+
+    if @organisation_name_change.save
+      notice_message = @organisation_name_change.immediate_change ? "Name change saved successfully." : "Name change scheduled for #{@organisation_name_change.formatted_change_date}."
+      redirect_to organisation_path(@organisation), notice: notice_message
+    else
+      render template: "organisations/change_name", status: :unprocessable_entity
+    end
+  end
+
+  def change_name
+    @organisation_name_change = OrganisationNameChange.new
+    render "organisations/change_name", layout: "application"
+  end
+
+private
+
+  def set_organisation
+    @organisation = Organisation.find(params[:id])
+  end
+
+  def set_previous_name_changes
+    @previous_name_changes = @organisation.name_changes_with_dates
+  end
+
+  def organisation_name_change_params
+    params.require(:organisation_name_change).permit(:name, :change_date, :immediate_change)
+  end
+end

app/helpers/tag_helper.rb

@@ -7,10 +7,12 @@ module TagHelper
     in_progress: "In progress",
     completed: "Completed",
     active: "Active",
+    inactive: "Inactive",
     incomplete: "Incomplete",
     deactivating_soon: "Deactivating soon",
     activating_soon: "Activating soon",
     reactivating_soon: "Reactivating soon",
+    scheduled: "Scheduled",
     deactivated: "Deactivated",
     deleted: "Deleted",
     merged: "Merged",
@@ -35,10 +37,12 @@ module TagHelper
     in_progress: "blue",
     completed: "green",
     active: "green",
+    inactive: "grey",
     incomplete: "red",
     deactivating_soon: "yellow",
     activating_soon: "blue",
     reactivating_soon: "blue",
+    scheduled: "blue",
     deactivated: "grey",
     deleted: "red",
     merged: "orange",

app/models/organisation.rb

@@ -8,6 +8,7 @@ class Organisation < ApplicationRecord
   has_many :parent_organisations, through: :parent_organisation_relationships
   has_many :child_organisation_relationships, foreign_key: :parent_organisation_id, class_name: "OrganisationRelationship"
   has_many :child_organisations, through: :child_organisation_relationships
+  has_many :organisation_name_changes, dependent: :destroy
 
   has_many :stock_owner_relationships, foreign_key: :child_organisation_id, class_name: "OrganisationRelationship"
   has_many :stock_owners, through: :stock_owner_relationships, source: :parent_organisation
@@ -71,6 +72,49 @@ class Organisation < ApplicationRecord
     end
   end
 
+  def name(date: Time.zone.now)
+    name_change = organisation_name_changes.find { |change| change.includes_date?(date) }
+    name_change&.name || read_attribute(:name)
+  end
+
+  def name_changes_with_dates
+    changes = fetch_name_changes_with_dates
+
+    if changes.any?
+      changes.unshift({
+                        name: self[:name],
+                        start_date: created_at,
+                        end_date: changes.first[:start_date]&.yesterday,
+                        status: Time.zone.now.to_date < changes.first[:start_date].to_date ? "scheduled" : "inactive",
+                      })
+    else
+      changes << { name: self[:name], start_date: created_at, end_date: nil, status: "active" }
+    end
+
+    changes.each do |change|
+      change[:status] ||= if change[:start_date].to_date > Time.zone.now.to_date
+                            "scheduled"
+                          elsif change[:end_date].nil? || change[:end_date].to_date >= Time.zone.now.to_date
+                            "active"
+                          else
+                            "inactive"
+                          end
+    end
+
+    changes
+  end
+
+  def fetch_name_changes_with_dates
+    organisation_name_changes.order(:change_date).map.with_index do |change, index|
+      next_change = organisation_name_changes.order(:change_date)[index + 1]
+      {
+        name: change.name,
+        start_date: change.change_date,
+        end_date: next_change&.change_date&.yesterday,
+      }
+    end
+  end
+
   def can_be_managed_by?(organisation:)
     organisation == self || managing_agents.include?(organisation)
   end
@@ -191,8 +235,9 @@ class Organisation < ApplicationRecord
     update!(discarded_at: Time.zone.now)
   end
 
-  def label
-    status == :deleted ? "#{name} (deleted)" : name
+  def label(date:)
+    date ||= Time.zone.now
+    status == :deleted ? "#{name(date:)} (deleted)" : name(date:)
   end
 
   def has_visible_users?

app/models/organisation_name_change.rb

@@ -0,0 +1,68 @@
+class OrganisationNameChange < ApplicationRecord
+  belongs_to :organisation
+
+  scope :visible, -> { where(discarded_at: nil) }
+
+  validates :name, presence: true
+  validates :change_date, presence: true, unless: -> { immediate_change }
+  validate :change_date_must_be_after_last_change_date
+  validate :name_must_be_different_from_current
+
+  attr_accessor :immediate_change
+
+  before_validation :set_change_date_if_immediate
+
+  has_paper_trail
+
+  def includes_date?(date)
+    change_date <= date && (next_change&.change_date.nil? || next_change&.change_date > date)
+  end
+
+  def before_date?(date)
+    change_date < date
+  end
+
+  def after_date?(date)
+    change_date > date
+  end
+
+  def next_change
+    organisation.organisation_name_changes.where("change_date > ?", change_date).order(change_date: :asc).first
+  end
+
+  def previous_change
+    organisation.organisation_name_changes.where("change_date < ?", change_date).order(change_date: :desc).first
+  end
+
+  def active?(date = Time.zone.now)
+    includes_date?(date)
+  end
+
+  def formatted_change_date(format = :govuk_date)
+    change_date.to_formatted_s(format)
+  end
+
+private
+
+  def set_change_date_if_immediate
+    self.change_date = Time.zone.now if immediate_change
+  end
+
+  def change_date_must_be_after_last_change_date
+    return if change_date.blank?
+
+    last_change_date = organisation.organisation_name_changes.where("change_date < ?", change_date).order(change_date: :desc).first&.change_date
+    if last_change_date && change_date <= last_change_date
+      errors.add(:change_date, "Start date must be after the last change date (#{last_change_date}).")
+    end
+  end
+
+  def name_must_be_different_from_current
+    return if name.blank? || change_date.blank?
+
+    if name == organisation.name(date: change_date)
+      errors.add(:name, "New name must be different from the current name on the change date.")
+    end
+  end
+end
+

app/views/organisations/change_name.html.erb

@@ -1,19 +1,66 @@
 <% content_for :title, "Change #{@organisation.name}’s name" %>
 
 <% content_for :before_content do %>
-  <%= govuk_back_link(href: :back) %>
+  <%= govuk_back_link(href: details_organisation_path(@organisation)) %>
 <% end %>
 
-<%= form_for(@organisation, as: :organisation, html: { method: :patch }) do |f| %>
+<%= form_for(@organisation_name_change, url: change_name_organisation_path(@organisation), html: { method: :post }) do |f| %>
   <div class="govuk-grid-row">
     <div class="govuk-grid-column-two-thirds">
+      <%= f.govuk_error_summary %>
+
       <h1 class="govuk-heading-l">
         <%= content_for(:title) %>
       </h1>
 
-      <%= f.govuk_text_field :name, autocomplete: "name", label: { size: "m" } %>
+      <%= f.govuk_text_field :name, autocomplete: "name", label: { text: "Enter new name", size: "m" }, value: @organisation.name %>
+
+      <%= govuk_details(summary_text: "View name history") do %>
+        <%= govuk_table do |table| %>
+          <%= table.with_head do |head| %>
+            <% head.with_row do |row| %>
+              <% row.with_cell(header: true, text: "Name") %>
+              <% row.with_cell(header: true, text: "Start Date") %>
+              <% row.with_cell(header: true, text: "End Date") %>
+              <% row.with_cell(header: true, text: "Status") %>
+            <% end %>
+          <% end %>
+          <% @previous_name_changes.each do |change| %>
+            <%= table.with_body do |body| %>
+              <% body.with_row do |row| %>
+                <% row.with_cell(text: change[:name]) %>
+                <% row.with_cell(text: change[:start_date]&.to_formatted_s(:govuk_date)) %>
+                <% row.with_cell(text: change[:end_date]&.to_formatted_s(:govuk_date) || "None") %>
+                <% row.with_cell text: status_tag(change[:status].to_sym) %>
+              <% end %>
+            <% end %>
+          <% end %>
+        <% end %>
+      <% end %>
+
+      <%= f.govuk_radio_buttons_fieldset :immediate_change,
+                                         legend: { text: "Does this change take effect starting today?", size: "m" } do %>
+        <%= f.govuk_radio_button :immediate_change, "true", label: { text: "Yes" } %>
+        <%= f.govuk_radio_button :immediate_change, "false",
+                                 label: { text: "No" },
+                                 "data-controller": "conditional-question",
+                                 "data-action": "click->conditional-question#displayConditional",
+                                 "data-info": { conditional_questions: { scheduled_date: [false] } }.to_json do %>
+          <%= render partial: "components/date_picker", locals: {
+            resource: @organisation_name_change,
+            question_id: :change_date,
+            legend: { text: "Set start date", size: "m" },
+            resource_type: "organisation_name_change",
+            hint: "For example, 13/9/2025",
+            f: f
+          } %>
+        <% end %>
+      <% end %>
 
-      <%= f.govuk_submit "Save changes" %>
+      <div class="govuk-button-group">
+        <%= f.govuk_submit "Save changes" %>
+        <%= govuk_button_link_to "Cancel", details_organisation_path(@organisation), secondary: true %>
+      </div>
     </div>
   </div>
 <% end %>

config/routes.rb

@@ -156,7 +156,8 @@ Rails.application.routes.draw do
       get "details", to: "organisations#details"
       get "data-sharing-agreement", to: "organisations#data_sharing_agreement"
       post "data-sharing-agreement", to: "organisations#confirm_data_sharing_agreement"
-      get "change-name", to: "organisations#change_name", as: "change_name"
+      get "change-name", to: "organisation_name_changes#change_name", as: "change_name"
+      post "change-name", to: "organisation_name_changes#create"
 
       get "users", to: "organisations#users"
       get "lettings-logs", to: "organisations#lettings_logs"