add labware updated_at value and return the latest one

app/models/labware.rb

@@ -368,8 +368,18 @@ def obtain_retention_instructions
     metadata.symbolize_keys[:retention_instruction]
   end
 
-  def lookup_labwhere_location
-    lookup_labwhere(machine_barcode) || lookup_labwhere(human_barcode)
+  def lookup_labwhere_location # rubocop:todo Metrics/AbcSize, Metrics/CyclomaticComplexity
+    machine_lookup = lookup_labwhere(machine_barcode)
+    human_lookup = lookup_labwhere(human_barcode)
+
+    valid_lookups = [machine_lookup, human_lookup].compact.select { |lookup| lookup[:location].present? }
+    return valid_lookups.max_by { |lookup| lookup[:updated_at] || Time.zone.at(0) }[:location] if valid_lookups.any?
+
+    return 'Not found - There is a problem with Labwhere' if [machine_lookup, human_lookup].any? do |lookup|
+      lookup&.dig(:error)
+    end
+
+    nil
   end
 
   def lookup_labwhere(barcode)
@@ -378,9 +388,23 @@ def lookup_labwhere(barcode)
     rescue StandardError => e
       # rescue LabWhereClient::LabwhereException => e
       Rails.logger.error { e }
-      return 'Not found - There is a problem with Labwhere'
+      return { error: true }
     end
-    info_from_labwhere.location.location_info if info_from_labwhere.present? && info_from_labwhere.location.present?
+
+    return nil unless info_from_labwhere.present? && info_from_labwhere.location.present?
+
+    {
+      location: info_from_labwhere.location.location_info,
+      updated_at: parse_labwhere_timestamp(info_from_labwhere.updated_at)
+    }
+  end
+
+  def parse_labwhere_timestamp(timestamp)
+    return if timestamp.blank?
+
+    Time.zone.parse(timestamp)
+  rescue ArgumentError
+    nil
   end
 end
 # rubocop:enable Metrics/ClassLength

lib/lab_where_client.rb

@@ -91,7 +91,7 @@ def self.included(base)
   class Labware < Endpoint
     endpoint_name 'labwares'
 
-    attr_reader :barcode, :location
+    attr_reader :barcode, :location, :updated_at
 
     def self.find_by_barcode(barcode)
       return nil if barcode.blank?
@@ -102,7 +102,8 @@ def self.find_by_barcode(barcode)
 
     def initialize(params)
       @barcode = params['barcode']
-      @location = Location.new(params['location'])
+      @updated_at = params['updated_at']
+      @location = Location.new(params['location']) if params['location'].present?
     end
   end
 
@@ -155,7 +156,7 @@ def valid?
   class Location < Endpoint
     endpoint_name 'locations'
 
-    attr_reader :name, :parentage, :barcode
+    attr_reader :name, :parentage, :barcode, :updated_at
 
     def self.find_by_barcode(barcode)
       return nil if barcode.blank?
@@ -168,6 +169,7 @@ def initialize(params)
       @name = params['name']
       @parentage = params['parentage']
       @barcode = params['barcode']
+      @updated_at = params['updated_at']
     end
 
     def location_info

spec/lib/lab_where_client_spec.rb

@@ -83,4 +83,26 @@
       end
     end
   end
+
+  describe LabWhereClient::Labware do
+    let(:params) do
+      {
+        'barcode' => '123456',
+        'updated_at' => 'Wednesday May  6 2026 10:46',
+        'location' => {
+          'name' => 'f1',
+          'parentage' => 'Sanger / Ogilvie / AA216',
+          'barcode' => 'lw-f1-26214',
+          'updated_at' => 'Tuesday June  6 2023 16:26'
+        }
+      }
+    end
+
+    it 'captures labware and location updated_at values from the API payload' do
+      labware = described_class.new(params)
+
+      expect(labware.updated_at).to eq('Wednesday May  6 2026 10:46')
+      expect(labware.location.updated_at).to eq('Tuesday June  6 2023 16:26')
+    end
+  end
 end

spec/models/labware_spec.rb

@@ -133,6 +133,66 @@
       plate = create(:plate)
       expect(plate.storage_location).to eq('Not found - There is a problem with Labwhere')
     end
+
+    it 'chooses the newer location when both machine and human barcode lookups return values' do
+      plate = create(:plate)
+
+      allow(LabWhereClient::Labware).to receive(:find_by_barcode).with(plate.machine_barcode).and_return(
+        LabWhereClient::Labware.new(
+          {
+            'barcode' => plate.machine_barcode,
+            'updated_at' => 'Wednesday May  6 2026 10:46',
+            'location' => {
+              'name' => 'f1',
+              'parentage' => 'Sanger / Ogilvie / AA216',
+              'barcode' => 'lw-f1-26214',
+              'updated_at' => 'Wednesday May  6 2026 10:46'
+            }
+          }
+        )
+      )
+      allow(LabWhereClient::Labware).to receive(:find_by_barcode).with(plate.human_barcode).and_return(
+        LabWhereClient::Labware.new(
+          {
+            'barcode' => plate.human_barcode,
+            'updated_at' => 'Wednesday May  7 2026 10:46',
+            'location' => {
+              'name' => 'f2',
+              'parentage' => 'Sanger / Ogilvie / AA216',
+              'barcode' => 'lw-f2-26214',
+              'updated_at' => 'Wednesday May  7 2026 10:46'
+            }
+          }
+        )
+      )
+
+      expect(plate.labwhere_location).to eq('Sanger / Ogilvie / AA216 - f2')
+    end
+
+    it 'falls back to human barcode location when machine barcode lookup raises an error' do
+      plate = create(:plate)
+
+      allow(LabWhereClient::Labware).to receive(:find_by_barcode).with(plate.machine_barcode).and_raise(
+        StandardError,
+        'Timed out reading data from server'
+      )
+      allow(LabWhereClient::Labware).to receive(:find_by_barcode).with(plate.human_barcode).and_return(
+        LabWhereClient::Labware.new(
+          {
+            'barcode' => plate.human_barcode,
+            'updated_at' => 'Wednesday May  7 2026 10:46',
+            'location' => {
+              'name' => 'f2',
+              'parentage' => 'Sanger / Ogilvie / AA216',
+              'barcode' => 'lw-f2-26214',
+              'updated_at' => 'Wednesday May  7 2026 10:46'
+            }
+          }
+        )
+      )
+
+      expect(plate.labwhere_location).to eq('Sanger / Ogilvie / AA216 - f2')
+    end
   end
 
   context 'when retrieving retention instructions' do

spec/models/location_report_spec.rb

@@ -200,6 +200,10 @@
     end
 
     describe 'report generation' do
+      before do
+        allow(LabWhereClient::Labware).to receive(:find_by_barcode).and_return(nil)
+      end
+
       shared_examples 'a successful report' do
         it 'generates the expected report rows' do
           expect(location_report.save).to be_truthy