PP-11867: Test getting the access token

src/main/java/uk/gov/pay/api/app/config/PublicApiConfig.java

@@ -39,6 +39,9 @@ public class PublicApiConfig extends Configuration {
     @NotNull
     @JsonProperty
     private RedisConfiguration redis;
+
+    @JsonProperty
+    private TinkConfiguration tinkConfiguration;
 
     @Valid
     @NotNull
@@ -88,6 +91,10 @@ public RedisConfiguration getRedisConfiguration() {
         return redis;
     }
 
+    public TinkConfiguration getTinkConfiguration() {
+        return tinkConfiguration;
+    }
+
     public Optional<URI> getEcsContainerMetadataUriV4() {
         return Optional.ofNullable(ecsContainerMetadataUriV4);
     }

src/main/java/uk/gov/pay/api/app/config/TinkConfiguration.java

@@ -0,0 +1,23 @@
+package uk.gov.pay.api.app.config;
+
+import javax.validation.Valid;
+import javax.validation.constraints.NotNull;
+
+public class TinkConfiguration {
+
+    @Valid
+    @NotNull
+    private String clientId;
+
+    @Valid
+    @NotNull
+    private String clientSecret;
+
+    public String getClientId() {
+        return clientId;
+    }
+
+    public String getClientSecret() {
+        return clientSecret;
+    }
+}

src/main/java/uk/gov/pay/api/model/tink/TinkTokenResponse.java

@@ -0,0 +1,34 @@
+package uk.gov.pay.api.model.tink;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+
+/*
+for e.g.
+{
+  "token_type" : "bearer",
+  "expires_in" : 1799,
+  "access_token" : "{YOUR_CLIENT_ACCESS_TOKEN}",
+  "scope" : "payment:read,payment:write",
+  "id_hint" : null
+}
+ */
+@JsonInclude(JsonInclude.Include.NON_NULL)
+@JsonIgnoreProperties(ignoreUnknown = true)
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+public class TinkTokenResponse {
+
+    private String tokenType;
+
+    private String accessToken;
+
+    public String getTokenType() {
+        return tokenType;
+    }
+
+    public String getAccessToken() {
+        return accessToken;
+    }
+}

src/main/java/uk/gov/pay/api/service/OpenBankingService.java

@@ -0,0 +1,51 @@
+package uk.gov.pay.api.service;
+
+import org.apache.http.HttpResponse;
+import uk.gov.pay.api.app.config.TinkConfiguration;
+import uk.gov.pay.api.model.tink.TinkTokenResponse;
+
+import javax.inject.Inject;
+import javax.ws.rs.client.Client;
+import javax.ws.rs.client.Entity;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.MultivaluedHashMap;
+import javax.ws.rs.core.MultivaluedMap;
+import javax.ws.rs.core.Response;
+
+import static javax.ws.rs.core.Response.Status.OK;
+
+public class OpenBankingService {
+
+    private final Client client;
+
+    private final TinkConfiguration tinkConfiguration;
+
+    @Inject
+    public OpenBankingService(Client client, TinkConfiguration tinkConfiguration) {
+        this.client = client;
+        this.tinkConfiguration = tinkConfiguration;
+    }
+
+
+    /*
+    Access token expire every 30 minutes so a to-do here would be to 1) refresh the token every 25 minutes on an 
+    internal scheduler OR 2) refresh the token based on the expiry "expires_in"
+     */
+    public String getAccessToken() {
+        MultivaluedMap<String, String> map = new MultivaluedHashMap<>(4);
+        map.add("client_id", tinkConfiguration.getClientId());
+        map.add("client_secret", tinkConfiguration.getClientSecret());
+        map.add("grant_type", "client_credentials");
+        map.add("scope", "payment:read,payment:write");
+        Response response = client.target("https://api.tink.com/api/v1/oauth/token")
+                .request()
+                .accept(MediaType.APPLICATION_JSON)
+                .post(Entity.form(map));
+
+        if (response.getStatus() == OK.getStatusCode()) {
+            return response.readEntity(TinkTokenResponse.class).getAccessToken();
+        } else {
+            throw new RuntimeException("Response from getting a Tink token was not 200.");
+        }
+    }
+}

src/test/java/uk/gov/pay/api/it/contract/OpenBankingServiceTest.java

@@ -0,0 +1,34 @@
+package uk.gov.pay.api.it.contract;
+
+import io.dropwizard.testing.junit.DropwizardAppRule;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import uk.gov.pay.api.app.PublicApi;
+import uk.gov.pay.api.app.config.PublicApiConfig;
+import uk.gov.pay.api.service.OpenBankingService;
+
+import javax.ws.rs.client.ClientBuilder;
+
+import static io.dropwizard.testing.ResourceHelpers.resourceFilePath;
+
+public class OpenBankingServiceTest {
+
+    @Rule
+    public DropwizardAppRule<PublicApiConfig> app = new DropwizardAppRule<>(
+            PublicApi.class,
+            resourceFilePath("config/test-config.yaml"));
+
+    private OpenBankingService openBankingService;
+
+    @Before
+    public void before() {
+        openBankingService = new OpenBankingService(ClientBuilder.newBuilder().build(), 
+                app.getConfiguration().getTinkConfiguration());
+    }
+
+    @Test
+    public void testGetAccessToken() {
+        System.out.println(openBankingService.getAccessToken());
+    }
+}

src/test/resources/config/test-config.yaml

@@ -53,3 +53,7 @@ apiKeyHmacSecret: qwer9yuhgf
 authenticationCachePolicy: expireAfterWrite=3s
 
 ecsContainerMetadataUriV4: ${ECS_CONTAINER_METADATA_URI_V4:-}
+
+tinkConfiguration:
+  clientId: ${TINK_CLIENT_ID:-}
+  clientSecret: ${TINK_CLIENT_SECRET:-}