Add method for retrieving contact list from own mailbox

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxApi.java

@@ -6,6 +6,7 @@ import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.mailbox.MailboxProperties;
 
 import java.io.IOException;
+import java.util.Collection;
 
 import javax.annotation.concurrent.Immutable;
 
@@ -46,6 +47,13 @@ interface MailboxApi {
 	void deleteContact(MailboxProperties properties, ContactId contactId)
 			throws IOException, ApiException;
 
+	/**
+	 * Gets a list of {@link ContactId}s from the mailbox.
+	 * These are the contacts that the mailbox already knows about.
+	 */
+	Collection<ContactId> getContacts(MailboxProperties properties)
+			throws IOException, ApiException;
+
 	@Immutable
 	@JsonSerialize
 	class MailboxContact {

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxApiImpl.java

@@ -10,6 +10,9 @@ import org.briarproject.bramble.api.mailbox.MailboxProperties;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
 
 import javax.inject.Inject;
 
@@ -127,6 +130,38 @@ class MailboxApiImpl implements MailboxApi {
 		if (response.code() != 200) throw new ApiException();
 	}
 
+	@Override
+	public Collection<ContactId> getContacts(MailboxProperties properties)
+			throws IOException, ApiException {
+		if (!properties.isOwner()) throw new IllegalArgumentException();
+		Request request = getRequestBuilder(properties.getAuthToken())
+				.url(properties.getOnionAddress() + "/contacts")
+				.build();
+		OkHttpClient client = httpClientProvider.get();
+		Response response = client.newCall(request).execute();
+		if (response.code() != 200) throw new ApiException();
+
+		ResponseBody body = response.body();
+		if (body == null) throw new ApiException();
+		try {
+			JsonNode node = mapper.readTree(body.string());
+			JsonNode contactsNode = node.get("contacts");
+			if (contactsNode == null || !contactsNode.isArray()) {
+				throw new ApiException();
+			}
+			List<ContactId> list = new ArrayList<>();
+			for (JsonNode contactNode : contactsNode) {
+				if (!contactNode.isNumber()) throw new ApiException();
+				int id = contactNode.intValue();
+				if (id < 1) throw new ApiException();
+				list.add(new ContactId(id));
+			}
+			return list;
+		} catch (JacksonException e) {
+			throw new ApiException();
+		}
+	}
+
 	private Request.Builder getRequestBuilder(String token) {
 		return new Request.Builder()
 				.addHeader("Authorization", "Bearer " + token);

bramble-core/src/test/java/org/briarproject/bramble/mailbox/MailboxApiTest.java

@@ -9,6 +9,9 @@ import org.briarproject.bramble.mailbox.MailboxApi.TolerableFailureException;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.junit.Test;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import javax.annotation.Nonnull;
 import javax.net.SocketFactory;
 
@@ -17,6 +20,7 @@ import okhttp3.mockwebserver.MockResponse;
 import okhttp3.mockwebserver.MockWebServer;
 import okhttp3.mockwebserver.RecordedRequest;
 
+import static java.util.Collections.singletonList;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static org.briarproject.bramble.test.TestUtils.getContactId;
 import static org.briarproject.bramble.test.TestUtils.getMailboxSecret;
@@ -263,6 +267,100 @@ public class MailboxApiTest extends BrambleTestCase {
 				api.deleteContact(properties, contactId));
 	}
 
+	@Test
+	public void testGetContacts() throws Exception {
+		ContactId contactId2 = getContactId();
+		String validResponse1 = "{\"contacts\": [" + contactId.getInt() + "] }";
+		String validResponse2 = "{\"contacts\": [" + contactId.getInt() + ", " +
+				contactId2.getInt() + "] }";
+		String invalidResponse1 = "{\"foo\":\"bar\"}";
+		String invalidResponse2 = "{\"contacts\":{\"foo\":\"bar\"}}";
+		String invalidResponse3 = "{\"contacts\": [1, 2, \"foo\"] }";
+
+		MockWebServer server = new MockWebServer();
+		server.enqueue(new MockResponse().setBody(validResponse1));
+		server.enqueue(new MockResponse().setBody(validResponse2));
+		server.enqueue(new MockResponse());
+		server.enqueue(new MockResponse().setBody(invalidResponse1));
+		server.enqueue(new MockResponse().setBody(invalidResponse2));
+		server.enqueue(new MockResponse().setBody(invalidResponse3));
+		server.enqueue(new MockResponse().setResponseCode(401));
+		server.enqueue(new MockResponse().setResponseCode(500));
+		server.start();
+		String baseUrl = getBaseUrl(server);
+		MailboxProperties properties =
+				new MailboxProperties(baseUrl, token, true);
+
+		// valid response with two contacts
+		assertEquals(singletonList(contactId), api.getContacts(properties));
+		RecordedRequest request1 = server.takeRequest();
+		assertEquals("/contacts", request1.getPath());
+		assertEquals("GET", request1.getMethod());
+		assertToken(request1, token);
+
+		// valid response with two contacts
+		List<ContactId> contacts = new ArrayList<>();
+		contacts.add(contactId);
+		contacts.add(contactId2);
+		assertEquals(contacts, api.getContacts(properties));
+		RecordedRequest request2 = server.takeRequest();
+		assertEquals("/contacts", request2.getPath());
+		assertEquals("GET", request2.getMethod());
+		assertToken(request2, token);
+
+		// empty body
+		assertThrows(ApiException.class, () -> api.getContacts(properties));
+		RecordedRequest request3 = server.takeRequest();
+		assertEquals("/contacts", request3.getPath());
+		assertEquals("GET", request3.getMethod());
+		assertToken(request3, token);
+
+		// invalid response: no contacts key
+		assertThrows(ApiException.class, () -> api.getContacts(properties));
+		RecordedRequest request4 = server.takeRequest();
+		assertEquals("/contacts", request4.getPath());
+		assertEquals("GET", request4.getMethod());
+		assertToken(request4, token);
+
+		// invalid response: no list in contacts
+		assertThrows(ApiException.class, () -> api.getContacts(properties));
+		RecordedRequest request5 = server.takeRequest();
+		assertEquals("/contacts", request5.getPath());
+		assertEquals("GET", request5.getMethod());
+		assertToken(request5, token);
+
+		// invalid response: list with non-numbers
+		assertThrows(ApiException.class, () -> api.getContacts(properties));
+		RecordedRequest request6 = server.takeRequest();
+		assertEquals("/contacts", request6.getPath());
+		assertEquals("GET", request6.getMethod());
+		assertToken(request6, token);
+
+		// 401 not authorized
+		assertThrows(ApiException.class, () -> api.getContacts(properties));
+		RecordedRequest request7 = server.takeRequest();
+		assertEquals("/contacts", request7.getPath());
+		assertEquals("GET", request7.getMethod());
+		assertToken(request7, token);
+
+		// 500 internal server error
+		assertThrows(ApiException.class, () -> api.getContacts(properties));
+		RecordedRequest request8 = server.takeRequest();
+		assertEquals("/contacts", request8.getPath());
+		assertEquals("GET", request8.getMethod());
+		assertToken(request8, token);
+	}
+
+	@Test
+	public void testGetContactsOnlyForOwner() {
+		MailboxProperties properties =
+				new MailboxProperties("", token, false);
+		assertThrows(
+				IllegalArgumentException.class,
+				() -> api.getContacts(properties)
+		);
+	}
+
 	private String getBaseUrl(MockWebServer server) {
 		String baseUrl = server.url("").toString();
 		return baseUrl.substring(0, baseUrl.length() - 1);