AP-4512: Add linking case invitation

Add controller, form, view and spec for page which asks
user if they would like to link their application to
another application

app/controllers/providers/linking_case_invitations_controller.rb

@@ -0,0 +1,23 @@
+module Providers
+  class LinkingCaseInvitationsController < ProviderBaseController
+    def show
+      @form = LinkingCase::InvitationForm.new(model: legal_aid_application)
+    end
+
+    def update
+      @form = LinkingCase::InvitationForm.new(form_params)
+
+      render :show unless save_continue_or_draft(@form)
+    end
+
+  private
+
+    def form_params
+      merge_with_model(legal_aid_application) do
+        next {} unless params[:legal_aid_application]
+
+        params.require(:legal_aid_application).permit(:link_case)
+      end
+    end
+  end
+end

app/forms/linking_case/invitation_form.rb

@@ -0,0 +1,9 @@
+module LinkingCase
+  class InvitationForm < BaseForm
+    form_for LegalAidApplication
+
+    attr_accessor :link_case
+
+    validates :link_case, presence: true, unless: proc { draft? || link_case.present? }
+  end
+end

app/services/flow/flows/provider_start.rb

@@ -20,6 +20,10 @@ class ProviderStart < FlowSteps
           end,
           check_answers: :check_provider_answers,
         },
+        linking_case_invitations: {
+          path: ->(application) { urls.providers_legal_aid_application_linking_case_invitation_path(application) },
+          forward: :address_lookups,
+        },
         address_lookups: {
           path: ->(application) { urls.providers_legal_aid_application_address_lookup_path(application) },
           forward: :address_selections,

app/views/providers/linking_case_invitations/show.html.erb

@@ -0,0 +1,18 @@
+<%= form_with(
+      url: providers_legal_aid_application_linking_case_invitation_path,
+      model: @form,
+      method: :patch,
+      local: true,
+    ) do |form| %>
+
+  <%= page_template page_title: t(".heading"),
+                    template: :basic,
+                    form: do %>
+
+    <%= form.govuk_collection_radio_buttons :link_case, yes_no_options, :value, :label,
+                                            legend: { text: t(".heading"), size: "xl", tag: "h1" },
+                                            hint: { text: t(".hint") } %>
+
+    <%= next_action_buttons(form:, show_draft: true) %>
+  <% end %>
+<% end %>

config/locales/en/activemodel.yml

@@ -491,6 +491,8 @@ en:
               date_not_in_range: "The date you used delegated functions cannot be before %{months}"
             client_declaration_confirmed:
               accepted: Confirm this information is correct and that you'll get a signed declaration
+            link_case:
+              blank: Select yes if you would like to link an application to your application
         other_assets_declaration:
           attributes:
             valuable_items_value:

config/locales/en/providers.yml

@@ -388,6 +388,10 @@ en:
         h1-heading: Is %{office_code} your office account number?
         error: Select yes if this is the account number of the office handling this application
         no_another_office: No, another office is handling this application
+    linking_case_invitations:
+      show:
+        heading: Do you want to link an application to your application?
+        hint: Guidance about linking cases
     proceeding_merits_task:
       linked_children:
         show:

config/routes.rb

@@ -200,6 +200,7 @@
       resource :in_scope_of_laspo, only: %i[show update], controller: "application_merits_task/in_scope_of_laspos"
       resource :nature_of_urgencies, only: %i[show update], controller: "application_merits_task/nature_of_urgencies"
       resource :merits_task_list, only: %i[show update]
+      resource :linking_case_invitation, only: %i[show update]
 
       resource :uploaded_evidence_collection, only: %i[show update destroy] do
         get "/list", to: "uploaded_evidence_collections#list"

spec/requests/providers/linking_case_invitations_controller_spec.rb

@@ -0,0 +1,49 @@
+require "rails_helper"
+
+RSpec.describe Providers::LinkingCaseInvitationsController do
+  let(:legal_aid_application) { create(:legal_aid_application) }
+  let(:provider) { legal_aid_application.provider }
+
+  before { login_as provider }
+
+  describe "GET /providers/applications/:legal_aid_application_id/linking_case_invitation" do
+    it "renders page with expected heading" do
+      get providers_legal_aid_application_linking_case_invitation_path(legal_aid_application)
+      expect(response).to have_http_status(:ok)
+      expect(page).to have_css("h1", text: "Do you want to link an application to your application?")
+    end
+  end
+
+  describe "PATCH /providers/applications/:legal_aid_application_id/linking_case_invitation" do
+    before { patch providers_legal_aid_application_linking_case_invitation_path(legal_aid_application), params: }
+
+    context "when form submitted with Save as draft button" do
+      let(:params) { { legal_aid_application: { link_case: "" }, draft_button: "Save and come back later" } }
+
+      it "redirects to the list of applications" do
+        expect(response).to redirect_to providers_legal_aid_applications_path
+      end
+    end
+
+    context "when no chosen" do
+      let(:params) { { legal_aid_application: { link_case: "false" } } }
+
+      it "redirects to the address_lookup page" do
+        expect(response).to redirect_to(providers_legal_aid_application_address_lookup_path(legal_aid_application))
+      end
+    end
+
+    context "when no answer chosen" do
+      let(:params) { { legal_aid_application: { link_case: "" }, continue_button: "Save and continue" } }
+
+      it "stays on the page if there is a validation error" do
+        expect(response).to have_http_status(:ok)
+        expect(page).to have_error_message("Select yes if you would like to link an application to your application")
+      end
+    end
+
+    def have_error_message(text)
+      have_css(".govuk-error-summary__list > li", text:)
+    end
+  end
+end