Add find_by to do patient search in PDS

app/jobs/pds_lookup_job.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+class PDSLookupJob < ApplicationJob
+  include GoodJob::ActiveJobExtensions::Concurrency
+
+  queue_as :pds
+
+  # NHS API imposes a limit of 5 requests per second
+  good_job_control_concurrency_with perform_limit: 5,
+                                    perform_throttle: [5, 1.second],
+                                    key: -> { queue_name }
+
+  # Because the NHS API imposes a limit of 5 requests per second, we're almost
+  # certain to hit throttling and the default exponential backoff strategy
+  # appears to trigger more race conditions in the job performing code, meaning
+  # there’s more instances where more than 5 requests are attempted.
+  retry_on GoodJob::ActiveJobExtensions::Concurrency::ConcurrencyExceededError,
+           attempts: :unlimited,
+           wait: ->(_) { rand(0.5..5) }
+
+  def perform(**args)
+    NHS::PDS::Patient.find_by(**args)
+  end
+end

app/lib/nhs/pds/patient.rb

@@ -1,9 +1,32 @@
 # frozen_string_literal: true
 
 module NHS::PDS::Patient
+  SEARCH_FIELDS = %w[
+    _fuzzy-match
+    _exact-match
+    _history
+    _max-results
+    family
+    given
+    gender
+    birthdate
+    death-date
+    email
+    phone
+    address-postcode
+    general-practitioner
+  ].freeze
   class << self
     def find(nhs_number)
       NHS::PDS.connection.get("Patient/#{nhs_number}")
     end
+
+    def find_by(**attributes)
+      if (missing_attrs = (attributes.keys.map(&:to_s) - SEARCH_FIELDS)).any?
+        raise "Unrecognised attributes: #{missing_attrs.join(", ")}"
+      end
+
+      NHS::PDS.connection.get("Patient", attributes)
+    end
   end
 end

app/models/pds/patient.rb

@@ -7,16 +7,8 @@ class PDS::Patient
 
   class << self
     def find(nhs_number)
-      response =
-        JSON.parse(
-          Net::HTTP.get(
-            URI(
-              "https://sandbox.api.service.nhs.uk/personal-demographics/FHIR/R4/Patient/#{nhs_number}"
-            ),
-            "X-Request-ID": SecureRandom.uuid
-          )
-        )
-      from_pds_fhir_response(response)
+      response = NHS::PDS::Patient.find(nhs_number)
+      from_pds_fhir_response(JSON.parse(response.body))
     end
 
     private

lib/tasks/pds.rake

@@ -18,5 +18,36 @@ namespace :pds do
         puts response.body
       end
     end
+
+    desc "Find patient using patient info"
+    task find_by: :environment do |_, _args|
+      query = {
+        "_fuzzy-match" => ENV["_fuzzy_match"],
+        "_exact-match" => ENV["_exact_match"],
+        "_history" => ENV["_history"],
+        "_max-results" => ENV["_max_results"],
+        "given" => ENV["given"],
+        "family" => ENV["family"],
+        "gender" => ENV["gender"],
+        "birthdate" => ENV["birthdate"],
+        "death-date" => ENV["death_date"],
+        "email" => ENV["email"],
+        "phone" => ENV["phone"],
+        "address-postcode" => ENV["address_postcode"],
+        "general-practitioner" => ENV["general_practitioner"]
+      }.compact
+      response = NHS::PDS::Patient.find_by(**query)
+
+      $stdout.puts response.status unless response.status == 200
+      if $stdout.tty?
+        puts response.env.url
+        puts ""
+        puts response.headers.map { "#{_1}: #{_2}" }
+        puts ""
+        puts JSON.pretty_generate(JSON.parse(response.body))
+      else
+        puts response.body
+      end
+    end
   end
 end

spec/fixtures/patient_record.json

@@ -0,0 +1,125 @@
+{
+  "entry": [
+    {
+      "fullUrl": "https://int.api.service.nhs.uk/personal-demographics/FHIR/R4/Patient/9449306168",
+      "resource": {
+        "address": [
+          {
+            "extension": [
+              {
+                "extension": [
+                  {
+                    "url": "type",
+                    "valueCoding": {
+                      "code": "PAF",
+                      "system": "https://fhir.hl7.org.uk/CodeSystem/UKCore-AddressKeyType"
+                    }
+                  },
+                  {
+                    "url": "value",
+                    "valueString": "07352931"
+                  }
+                ],
+                "url": "https://fhir.hl7.org.uk/StructureDefinition/Extension-UKCore-AddressKey"
+              }
+            ],
+            "id": "gon1",
+            "line": ["103 PRESTON LANE", "TADWORTH", "SURREY"],
+            "period": {
+              "start": "2011-06-23"
+            },
+            "postalCode": "KT20 5HJ",
+            "use": "home"
+          }
+        ],
+        "birthDate": "1939-01-09",
+        "gender": "female",
+        "generalPractitioner": [
+          {
+            "id": "dp7s",
+            "identifier": {
+              "period": {
+                "start": "1951-08-09"
+              },
+              "system": "https://fhir.nhs.uk/Id/ods-organization-code",
+              "value": "H81109"
+            },
+            "type": "Organization"
+          }
+        ],
+        "id": "9449306168",
+        "identifier": [
+          {
+            "extension": [
+              {
+                "url": "https://fhir.hl7.org.uk/StructureDefinition/Extension-UKCore-NHSNumberVerificationStatus",
+                "valueCodeableConcept": {
+                  "coding": [
+                    {
+                      "code": "01",
+                      "display": "Number present and verified",
+                      "system": "https://fhir.hl7.org.uk/CodeSystem/UKCore-NHSNumberVerificationStatus",
+                      "version": "1.0.0"
+                    }
+                  ]
+                }
+              }
+            ],
+            "system": "https://fhir.nhs.uk/Id/nhs-number",
+            "value": "9449306168"
+          }
+        ],
+        "meta": {
+          "security": [
+            {
+              "code": "U",
+              "display": "unrestricted",
+              "system": "http://terminology.hl7.org/CodeSystem/v3-Confidentiality"
+            }
+          ],
+          "versionId": "6"
+        },
+        "name": [
+          {
+            "family": "LAWMAN",
+            "given": ["ELDREDA"],
+            "id": "frs8",
+            "period": {
+              "start": "1978-06-14"
+            },
+            "prefix": ["MS"],
+            "use": "usual"
+          }
+        ],
+        "resourceType": "Patient",
+        "telecom": [
+          {
+            "id": "6FF70BFB",
+            "period": {
+              "start": "2021-12-15"
+            },
+            "system": "email",
+            "use": "home",
+            "value": "jagdish.khunti1@nhs.net"
+          },
+          {
+            "id": "4B88618D",
+            "period": {
+              "start": "2021-12-15"
+            },
+            "system": "phone",
+            "use": "mobile",
+            "value": "07463657671"
+          }
+        ]
+      },
+      "search": {
+        "score": 1
+      }
+    }
+  ],
+  "resourceType": "Bundle",
+  "timestamp": "2024-08-31T10:40:34+00:00",
+  "total": 1,
+  "type": "searchset"
+}

spec/jobs/pds_lookup_job_spec.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+describe PDSLookupJob, type: :job do
+  it "calls the NHS::PDS::Patient.find_by" do
+    allow(NHS::PDS::Patient).to receive(:find_by)
+
+    described_class.perform_now(given: "name")
+
+    expect(NHS::PDS::Patient).to have_received(:find_by).with(given: "name")
+  end
+end

spec/lib/nhs/pds/patient_spec.rb

@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+describe NHS::PDS::Patient do
+  before do
+    allow(NHS::API).to receive(:connection).and_return(
+      Faraday.new do |builder|
+        stubbed_requests.each do |request, response|
+          builder.adapter :test do |stub|
+            stub.get(request) { response }
+          end
+        end
+      end
+    )
+  end
+
+  describe ".find" do
+    let(:stubbed_requests) do
+      [
+        [
+          "https://sandbox.api.service.nhs.uk/personal-demographics/FHIR/R4/Patient/9449306168",
+          [200, {}, "patient record as json"]
+        ]
+      ]
+    end
+
+    it "sends a GET request to retrieve a patient by their NHS number" do
+      response = described_class.find("9449306168").body
+
+      expect(response).to eq "patient record as json"
+    end
+  end
+
+  describe ".find_by" do
+    let(:stubbed_requests) do
+      [
+        [
+          "https://sandbox.api.service.nhs.uk/personal-demographics/FHIR/R4/Patient",
+          [200, {}, "patient record as json"]
+        ]
+      ]
+    end
+
+    it "sends a GET request to with the provided attributes" do
+      response =
+        described_class.find_by(
+          family: "Lawman",
+          gender: "female",
+          birthdate: "eq1939-01-09"
+        )
+
+      expect(response.body).to eq "patient record as json"
+    end
+
+    it "raises an error if an unrecognised attribute is provided" do
+      expect {
+        described_class.find_by(
+          given: "Eldreda",
+          family_name: "Lawman",
+          date_of_birth: "1939-01-09"
+        )
+      }.to raise_error("Unrecognised attributes: family_name, date_of_birth")
+    end
+  end
+end

spec/lib/nhs/pds_spec.rb

@@ -1,17 +1,7 @@
 # frozen_string_literal: true
 
 describe NHS::PDS do
-  before do
-    allow(NHS::API).to receive(:connection).and_return(
-      Faraday.new do |builder|
-        builder.adapter :test do |stub|
-          stub.get(
-            "https://sandbox.api.service.nhs.uk/personal-demographics/FHIR/R4/Patient/9000000009"
-          ) { [200, {}, {}.to_json] }
-        end
-      end
-    )
-  end
+  before { allow(NHS::API).to receive(:connection).and_return(Faraday.new) }
 
   describe ".connection" do
     it "sets the url" do
@@ -20,14 +10,4 @@
       ).to eq "https://sandbox.api.service.nhs.uk/personal-demographics/FHIR/R4"
     end
   end
-
-  describe NHS::PDS::Patient do
-    describe ".find_patient" do
-      it "sends a GET request to retrieve a patient by their NHS number" do
-        response = described_class.find("9000000009").body
-
-        expect(response).to eq "{}"
-      end
-    end
-  end
 end

spec/models/pds/patient_spec.rb

@@ -6,25 +6,20 @@
       File.read("spec/support/pds-get-patient-response.json")
     end
     let(:request_id) { "123e4567-e89b-12d3-a456-426614174000" }
+    let(:patient_json) do
+      File.read(Rails.root.join("spec/fixtures/patient_record.json"))
+    end
 
     before do
-      allow(SecureRandom).to receive(:uuid).and_return(request_id)
-      stub_request(
-        :get,
-        "https://sandbox.api.service.nhs.uk/personal-demographics/FHIR/R4/Patient/9000000009"
-      ).with(headers: { "X-Request-ID" => request_id }).to_return(
-        status: 200,
-        body: json_response
+      allow(NHS::PDS::Patient).to receive(:find).and_return(
+        instance_double(Faraday::Response, status: 200, body: json_response)
       )
     end
 
-    it "returns a patient with the correct attributes" do
-      patient = described_class.find("9000000009")
+    it "calls find_patient on PDS library" do
+      described_class.find("9449306168")
 
-      expect(patient.nhs_number).to eq("9000000009")
-      expect(patient.given_name).to eq("Jane")
-      expect(patient.family_name).to eq("Smith")
-      expect(patient.date_of_birth).to eq("2010-10-22")
+      expect(NHS::PDS::Patient).to have_received(:find).with("9449306168")
     end
   end
 end