add gateway logic and tests (#712)

Author: BushraAbdullahi

src/main/kotlin/uk/gov/justice/digital/hmpps/hmppsintegrationapi/gateways/NomisGateway.kt

@@ -37,6 +37,7 @@ import uk.gov.justice.digital.hmpps.hmppsintegrationapi.models.nomis.NomisSenten
 import uk.gov.justice.digital.hmpps.hmppsintegrationapi.models.nomis.NomisSentenceSummary
 import uk.gov.justice.digital.hmpps.hmppsintegrationapi.models.nomis.NomisTransactionResponse
 import uk.gov.justice.digital.hmpps.hmppsintegrationapi.models.nomis.NomisTransactionTransferResponse
+import uk.gov.justice.digital.hmpps.hmppsintegrationapi.models.nomis.visits.VisitBalances
 
 @Component
 class NomisGateway(
@@ -477,6 +478,30 @@ class NomisGateway(
     }
   }
 
+  fun getVisitBalances(offenderNumber: String): Response<VisitBalances?> {
+    val result =
+      webClient.request<VisitBalances>(
+        HttpMethod.GET,
+        "/api/bookings/offenderNo/$offenderNumber/visit/balances",
+        authenticationHeader(),
+        UpstreamApi.NOMIS,
+        badRequestAsError = true,
+      )
+
+    return when (result) {
+      is WebClientWrapperResponse.Success -> {
+        Response(data = result.data)
+      }
+
+      is WebClientWrapperResponse.Error -> {
+        Response(
+          data = null,
+          errors = result.errors,
+        )
+      }
+    }
+  }
+
   private fun authenticationHeader(): Map<String, String> {
     val token = hmppsAuthGateway.getClientToken("NOMIS")
 

src/main/kotlin/uk/gov/justice/digital/hmpps/hmppsintegrationapi/models/nomis/visits/VisitBalances.kt

@@ -0,0 +1,6 @@
+package uk.gov.justice.digital.hmpps.hmppsintegrationapi.models.nomis.visits
+
+data class VisitBalances(
+  val remainingVo: Long,
+  val remainingPvo: Long,
+)

src/test/kotlin/uk/gov/justice/digital/hmpps/hmppsintegrationapi/gateways/nomis/GetVisitBalancesForPersonTest.kt

@@ -0,0 +1,103 @@
+package uk.gov.justice.digital.hmpps.hmppsintegrationapi.gateways.nomis
+
+import io.kotest.core.spec.style.DescribeSpec
+import io.kotest.matchers.collections.shouldHaveSize
+import io.kotest.matchers.nulls.shouldNotBeNull
+import io.kotest.matchers.shouldBe
+import org.mockito.Mockito
+import org.mockito.internal.verification.VerificationModeFactory
+import org.mockito.kotlin.verify
+import org.mockito.kotlin.whenever
+import org.springframework.boot.test.context.ConfigDataApplicationContextInitializer
+import org.springframework.http.HttpStatus
+import org.springframework.test.context.ActiveProfiles
+import org.springframework.test.context.ContextConfiguration
+import org.springframework.test.context.bean.override.mockito.MockitoBean
+import uk.gov.justice.digital.hmpps.hmppsintegrationapi.extensions.removeWhitespaceAndNewlines
+import uk.gov.justice.digital.hmpps.hmppsintegrationapi.gateways.HmppsAuthGateway
+import uk.gov.justice.digital.hmpps.hmppsintegrationapi.gateways.NomisGateway
+import uk.gov.justice.digital.hmpps.hmppsintegrationapi.mockservers.HmppsAuthMockServer
+import uk.gov.justice.digital.hmpps.hmppsintegrationapi.mockservers.NomisApiMockServer
+import uk.gov.justice.digital.hmpps.hmppsintegrationapi.models.hmpps.UpstreamApi
+import uk.gov.justice.digital.hmpps.hmppsintegrationapi.models.hmpps.UpstreamApiError
+
+@ActiveProfiles("test")
+@ContextConfiguration(
+  initializers = [ConfigDataApplicationContextInitializer::class],
+  classes = [NomisGateway::class],
+)
+class GetVisitBalancesForPersonTest(
+  @MockitoBean val hmppsAuthGateway: HmppsAuthGateway,
+  val nomisGateway: NomisGateway,
+) : DescribeSpec({
+    val nomisApiMockServer = NomisApiMockServer()
+    val offenderNumber = "A7777ZZ"
+    val visitBalancesPath = "/api/bookings/offenderNo/$offenderNumber/visit/balances"
+
+    beforeEach {
+      nomisApiMockServer.start()
+      nomisApiMockServer.stubNomisApiResponse(
+        visitBalancesPath,
+        """
+        {
+          "remainingVo": 1073741824,
+          "remainingPvo": 1073741824,
+          "latestIepAdjustDate": "2025-03-04",
+          "latestPrivIepAdjustDate": "2025-03-04"
+        }
+        """.removeWhitespaceAndNewlines(),
+      )
+
+      Mockito.reset(hmppsAuthGateway)
+      whenever(hmppsAuthGateway.getClientToken("NOMIS")).thenReturn(HmppsAuthMockServer.TOKEN)
+    }
+
+    afterTest {
+      nomisApiMockServer.stop()
+    }
+
+    it("authenticates using HMPPS Auth with credentials") {
+      nomisGateway.getVisitBalances(offenderNumber)
+
+      verify(hmppsAuthGateway, VerificationModeFactory.times(1)).getClientToken("NOMIS")
+    }
+
+    it("returns visit balances for the matching offender number") {
+      val response = nomisGateway.getVisitBalances(offenderNumber)
+
+      response.data.shouldNotBeNull()
+      response.data?.remainingVo.shouldBe(1073741824)
+    }
+
+    it("returns an error when 400 Bad Request is returned because of an invalid request") {
+      nomisApiMockServer.stubNomisApiResponse(visitBalancesPath, "", HttpStatus.BAD_REQUEST)
+
+      val response = nomisGateway.getVisitBalances(offenderNumber)
+
+      response.errors.shouldHaveSize(1)
+      response.errors
+        .first()
+        .causedBy
+        .shouldBe(UpstreamApi.NOMIS)
+      response.errors
+        .first()
+        .type
+        .shouldBe(UpstreamApiError.Type.BAD_REQUEST)
+    }
+
+    it("returns an error when 404 Not Found is returned because no person is found") {
+      nomisApiMockServer.stubNomisApiResponse(visitBalancesPath, "", HttpStatus.NOT_FOUND)
+
+      val response = nomisGateway.getVisitBalances(offenderNumber)
+
+      response.errors.shouldHaveSize(1)
+      response.errors
+        .first()
+        .causedBy
+        .shouldBe(UpstreamApi.NOMIS)
+      response.errors
+        .first()
+        .type
+        .shouldBe(UpstreamApiError.Type.ENTITY_NOT_FOUND)
+    }
+  })