Infer la from postcode

.env.example

@@ -2,3 +2,5 @@ DB_USERNAME=postgres-user
 DB_PASSWORD=postgres-password
 CORE_EMAIL_USERNAME=email@example.com
 CORE_EMAIL_PASSWORD=password123
+OS_PLACES_API_KEY=xx
+

Gemfile

@@ -66,6 +66,7 @@ group :test do
   gem "factory_bot_rails"
   gem "selenium-webdriver", require: false
   gem "simplecov", require: false
+  gem "webmock"
   %w[rspec-core rspec-expectations rspec-mocks rspec-rails rspec-support].each do |lib|
     gem lib, git: "https://github.com/rspec/#{lib}.git", branch: "main", require: false
   end

Gemfile.lock

@@ -158,6 +158,8 @@ GEM
     childprocess (4.1.0)
     coderay (1.1.3)
     concurrent-ruby (1.1.9)
+    crack (0.4.5)
+      rexml
     crass (1.0.6)
     deep_merge (1.2.1)
     diff-lcs (1.4.4)
@@ -192,6 +194,7 @@ GEM
     has_scope (0.8.0)
       actionpack (>= 5.2)
       activesupport (>= 5.2)
+    hashdiff (1.0.1)
     hotwire-rails (0.1.3)
       rails (>= 6.0.0)
       stimulus-rails
@@ -389,6 +392,10 @@ GEM
       activemodel (>= 6.0.0)
       bindex (>= 0.4.0)
       railties (>= 6.0.0)
+    webmock (3.14.0)
+      addressable (>= 2.8.0)
+      crack (>= 0.3.2)
+      hashdiff (>= 0.4.0, < 2.0.0)
     webpacker (5.4.3)
       activesupport (>= 5.2)
       rack-proxy (>= 0.6.1)
@@ -445,6 +452,7 @@ DEPENDENCIES
   uk_postcode
   view_component
   web-console (>= 4.1.0)
+  webmock
   webpacker (~> 5.0)
 
 RUBY VERSION

app/models/case_log.rb

@@ -1,3 +1,7 @@
+require "uri"
+require "net/http"
+require "json"
+
 class CaseLogValidator < ActiveModel::Validator
   # Validations methods need to be called 'validate_' to run on model save
   # or form page submission
@@ -193,6 +197,14 @@ private
     self.hhmemb = other_hhmemb + 1 if other_hhmemb.present?
     self.renttype = RENT_TYPE_MAPPING[rent_type]
     self.lettype = "#{renttype} #{needstype} #{owning_organisation['Org type']}" if renttype.present? && needstype.present? && owning_organisation["Org type"].present?
+    self.la = get_la(property_postcode) if property_postcode.present?
+  end
+
+  def get_la(postcode)
+    uri = URI("https://api.os.uk/search/places/v1/postcode?key=#{ENV['OS_PLACES_API_KEY']}&postcode=#{postcode}&dataset=LPI")
+    res = Net::HTTP.get_response(uri)
+    response_body = JSON.parse(res.body)
+    response_body["results"][0]["LPI"]["ADMINISTRATIVE_AREA"].downcase.capitalize if res.is_a?(Net::HTTPSuccess) && (response_body["header"]["totalresults"]).to_i.positive?
   end
 
   def all_fields_completed?

spec/models/case_log_spec.rb

@@ -1,8 +1,12 @@
 require "rails_helper"
+require_relative "../request_helper"
 
 RSpec.describe Form, type: :model do
   let(:owning_organisation) { FactoryBot.create(:organisation) }
   let(:managing_organisation) { owning_organisation }
+  before do
+    RequestHelper.stub_http_requests
+  end
 
   describe "#new" do
     it "validates age is a number" do
@@ -1016,5 +1020,28 @@ RSpec.describe Form, type: :model do
       expect(record_from_db["month"]).to eq(10)
       expect(record_from_db["year"]).to eq(2021)
     end
+    
+    context "addresses" do
+      before do
+        stub_request(:get, /api.os.uk/)
+          .to_return(status: 200, body: "{\"header\": {\"totalresults\": \"1\"}, \"results\": [{\"LPI\": {\"ADMINISTRATIVE_AREA\": \"MANCHESTER\"}}]}", headers: {})
+      end
+
+      let!(:address_case_log) do
+        CaseLog.create({
+          managing_organisation: organisation,
+          owning_organisation: organisation,
+          property_postcode: "M1 1AE",
+        })
+      end
+
+      it "correctly infers postcode" do
+        address_case_log.reload
+
+        record_from_db = ActiveRecord::Base.connection.execute("select la from case_logs where id=#{address_case_log.id}").to_a[0]
+        expect(address_case_log.la).to eq("Manchester")
+        expect(record_from_db["la"]).to eq("E08000003")
+      end
+    end
   end
 end

spec/request_helper.rb

@@ -0,0 +1,9 @@
+require "webmock/rspec"
+
+module RequestHelper
+  def self.stub_http_requests
+    WebMock.disable_net_connect!(allow_localhost: true)
+    WebMock.stub_request(:get, /api.os.uk/)
+      .to_return(status: 200, body: "{\"header\": {\"totalresults\": \"0\"}}", headers: {})
+  end
+end