fetching customer by cristin id

buildSrc/src/main/groovy/nvacommons.java-conventions.gradle

@@ -9,7 +9,7 @@ plugins {
 }
 
 group 'com.github.bibsysdev'
-version = '1.41.2'
+version = '1.41.3'
 
 java {
     sourceCompatibility = JavaVersion.VERSION_17

clients/src/main/java/no/unit/nva/clients/GetCustomerResponse.java

@@ -0,0 +1,10 @@
+package no.unit.nva.clients;
+
+import java.net.URI;
+import java.util.UUID;
+import no.unit.nva.commons.json.JsonSerializable;
+
+public record GetCustomerResponse(URI id, UUID identifier, String name, String displayName, String shortName,
+                                  URI cristinId) implements JsonSerializable {
+
+}

clients/src/main/java/no/unit/nva/clients/IdentityServiceClient.java

@@ -7,6 +7,7 @@
 import static nva.commons.core.attempt.Try.attempt;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import java.net.URI;
+import java.net.URLEncoder;
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
@@ -29,6 +30,8 @@ public class IdentityServiceClient {
     private static final String API_PATH_USERS = "users";
     private static final String AUTH_HOST = new Environment().readEnv("BACKEND_CLIENT_AUTH_URL");
     private static final String API_HOST = new Environment().readEnv("API_HOST");
+    public static final String CUSTOMER_PATH_PARAM = "customer";
+    public static final String CRISTIN_ID_PATH_PARAM = "cristinId";
     private final AuthorizedBackendClient authorizedClient;
     private final HttpClient unauthorizedClient;
 
@@ -82,6 +85,25 @@ public GetUserResponse getUser(String userName) throws NotFoundException {
                    .orElseThrow(this::handleFailure);
     }
 
+    public GetCustomerResponse getCustomerByCristinId(URI topLevelOrgCristinId) throws NotFoundException {
+        var request = HttpRequest.newBuilder()
+                          .GET()
+                          .uri(constructCustomerGetPath(topLevelOrgCristinId));
+        return attempt(getHttpResponseCallable(request))
+                   .map(this::validateResponse)
+                   .map(r -> mapResponse(GetCustomerResponse.class, r))
+                   .orElseThrow(this::handleFailure);
+    }
+
+    private URI constructCustomerGetPath(URI topLevelOrgCristinId) {
+        var customerByCristinIdUri = UriWrapper.fromHost(API_HOST)
+                                    .addChild(CUSTOMER_PATH_PARAM)
+                                    .addChild(CRISTIN_ID_PATH_PARAM)
+                                    .getUri();
+        return URI.create(
+            customerByCristinIdUri + "/" + URLEncoder.encode(topLevelOrgCristinId.toString(), UTF_8));
+    }
+
     @JacocoGenerated
     private static CognitoCredentials fetchCredentials() {
         var secretsReader = new SecretsReader(SecretsReader.defaultSecretsManagerClient());

clients/src/test/java/no/unit/nva/clients/IdentityServiceClientTest.java

@@ -20,6 +20,7 @@
 import java.net.http.HttpResponse;
 import java.net.http.HttpResponse.BodyHandler;
 import java.util.List;
+import java.util.UUID;
 import no.unit.nva.auth.CognitoCredentials;
 import no.unit.nva.clients.GetUserResponse.Role;
 import no.unit.nva.clients.GetUserResponse.ViewingScope;
@@ -173,6 +174,29 @@ void shouldThrowNotFoundWhenHttpClientNotFound() throws IOException, Interrupted
         assertThrows(NotFoundException.class, action);
     }
 
+    @Test
+    void shouldReturnCustomerWhenRequested() throws NotFoundException, IOException, InterruptedException {
+        var customerCristinId = randomUri();
+        var expectedCustomer = createCustomer(customerCristinId);
+        var mockedResponse = mockResponse(expectedCustomer.toJsonString());
+        when(httpClient.send(any(HttpRequest.class), any(BodyHandler.class))).thenReturn(mockedResponse);
+
+        var actual = authorizedIdentityServiceClient.getCustomerByCristinId(customerCristinId);
+
+        assertEquals(expectedCustomer, actual);
+    }
+
+    @Test
+    void shouldThrowNotFoundWhenCustomerNotFound() throws IOException, InterruptedException {
+        when(httpClient.send(any(HttpRequest.class), any(BodyHandler.class))).thenReturn(notFoundResponse);
+        assertThrows(NotFoundException.class, () -> authorizedIdentityServiceClient.getCustomerByCristinId(randomUri()));
+    }
+
+    private GetCustomerResponse createCustomer(URI customerCristinId) {
+        return new GetCustomerResponse(randomUri(), UUID.randomUUID(), randomString(), randomString(), randomString(),
+                                       customerCristinId);
+    }
+
     private GetUserResponse createUser(String userName) {
         return GetUserResponse.builder()
                    .withUsername(userName)