feat: move org relationship errors to model

app/controllers/organisation_relationships_controller.rb

@@ -39,49 +39,32 @@ class OrganisationRelationshipsController < ApplicationController
 
   def create_housing_provider
     child_organisation = @organisation
-    if params[:organisation][:related_organisation_id].empty?
+    if params[:organisation][:related_organisation_id].present?
-      @organisation.errors.add :related_organisation_id, "You must choose a housing provider"
-      @organisations = Organisation.where.not(id: child_organisation.id).pluck(:id, :name)
-      render "organisation_relationships/add_housing_provider"
-      return
-    else
       parent_organisation = related_organisation
-      if OrganisationRelationship.exists?(child_organisation:, parent_organisation:)
-        @organisation.errors.add :related_organisation_id, "You have already added this housing provider"
-        @organisations = Organisation.where.not(id: child_organisation.id).pluck(:id, :name)
-        render "organisation_relationships/add_housing_provider"
-        return
-      elsif !parent_organisation.holds_own_stock
-        @organisation.errors.add :related_organisation_id, I18n.t("validations.scheme.owning_organisation.does_not_own_stock")
-        @organisations = Organisation.where.not(id: child_organisation.id).pluck(:id, :name)
-        render "organisation_relationships/add_housing_provider"
-        return
-      end
     end
-    create!(child_organisation:, parent_organisation:)
+    @resource = OrganisationRelationship.new(child_organisation:, parent_organisation:)
+    if @resource.save(context: :housing_provider)
       flash[:notice] = "#{related_organisation.name} is now one of #{current_user.data_coordinator? ? 'your' : "this organisation's"} housing providers"
       redirect_to housing_providers_organisation_path
+    else
+      @organisations = Organisation.where.not(id: child_organisation.id).pluck(:id, :name)
+      render "organisation_relationships/add_housing_provider", status: :unprocessable_entity
+    end
   end
 
   def create_managing_agent
     parent_organisation = @organisation
-    if params[:organisation][:related_organisation_id].empty?
+    if params[:organisation][:related_organisation_id].present?
-      @organisation.errors.add :related_organisation_id, "You must choose a managing agent"
-      @organisations = Organisation.where.not(id: parent_organisation.id).pluck(:id, :name)
-      render "organisation_relationships/add_managing_agent"
-      return
-    else
       child_organisation = related_organisation
-      if OrganisationRelationship.exists?(child_organisation:, parent_organisation:)
-        @organisation.errors.add :related_organisation_id, "You have already added this managing agent"
-        @organisations = Organisation.where.not(id: parent_organisation.id).pluck(:id, :name)
-        render "organisation_relationships/add_managing_agent"
-        return
-      end
     end
-    create!(child_organisation:, parent_organisation:)
+    @resource = OrganisationRelationship.new(child_organisation:, parent_organisation:)
+    if @resource.save(context: :managing_agent)
       flash[:notice] = "#{related_organisation.name} is now one of #{current_user.data_coordinator? ? 'your' : "this organisation's"} managing agents"
       redirect_to managing_agents_organisation_path
+    else
+      @organisations = Organisation.where.not(id: parent_organisation.id).pluck(:id, :name)
+      render "organisation_relationships/add_managing_agent", status: :unprocessable_entity
+    end
   end
 
   def remove_housing_provider

app/models/organisation_relationship.rb

@@ -1,4 +1,28 @@
 class OrganisationRelationship < ApplicationRecord
   belongs_to :child_organisation, class_name: "Organisation"
   belongs_to :parent_organisation, class_name: "Organisation"
+  validates :parent_organisation_id, uniqueness: { scope: [:child_organisation_id] }
+  validate :validate_housing_provider_relationship, on: :housing_provider
+  validate :validate_managing_agent_relationship, on: :managing_agent
+
+private
+
+  def validate_housing_provider_relationship
+    if parent_organisation_id.blank?
+      child_organisation.errors.add :related_organisation_id, "You must choose a housing provider"
+    elsif OrganisationRelationship.exists?(child_organisation:, parent_organisation:)
+      child_organisation.errors.add :related_organisation_id, "You have already added this housing provider"
+    elsif !parent_organisation.holds_own_stock
+      errors.add :parent_organisation_id
+      child_organisation.errors.add :related_organisation_id, I18n.t("validations.scheme.owning_organisation.does_not_own_stock")
+    end
+  end
+
+  def validate_managing_agent_relationship
+    if child_organisation_id.blank?
+      parent_organisation.errors.add :related_organisation_id, "You must choose a managing agent"
+    elsif OrganisationRelationship.exists?(child_organisation:, parent_organisation:)
+      parent_organisation.errors.add :related_organisation_id, "You have already added this managing agent"
+    end
+  end
 end

app/views/organisation_relationships/managing_agents.html.erb

@@ -11,7 +11,7 @@
     <p class="govuk-body">This organisation does not currently have any managing agents.</p>
   <% end %>
 <% else %>
-  <%= render partial: "organisations/headings", locals: { main: "This organisation managing agents", sub: current_user.organisation.name } %>
+  <%= render partial: "organisations/headings", locals: { main: "Your managing agents", sub: current_user.organisation.name } %>
   <p class="govuk-body">A managing agent can submit logs for this organisation.</p>
   <% if @total_count == 0 %>
     <p class="govuk-body">This organisation does not currently have any managing agents.</p>