From 008147248937cfc2cfaa2de23aa3adbbc06ce883 Mon Sep 17 00:00:00 2001
From: akwizgran <michael@briarproject.org>
Date: Tue, 11 Dec 2018 17:25:29 +0000
Subject: [PATCH] Add method for querying contact's client minor version.

---
 .../versioning/ClientVersioningManager.java   |  7 ++++
 .../ClientVersioningManagerImpl.java          | 38 +++++++++++++++----
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/bramble-api/src/main/java/org/briarproject/bramble/api/versioning/ClientVersioningManager.java b/bramble-api/src/main/java/org/briarproject/bramble/api/versioning/ClientVersioningManager.java
index 00b3d672c..76b261d1b 100644
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/versioning/ClientVersioningManager.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/versioning/ClientVersioningManager.java
@@ -38,6 +38,13 @@ public interface ClientVersioningManager {
 	Visibility getClientVisibility(Transaction txn, ContactId contactId,
 			ClientId clientId, int majorVersion) throws DbException;
 
+	/**
+	 * Returns the minor version of the given client that is supported by the
+	 * given contact, or -1 if the contact does not support the client.
+	 */
+	int getClientMinorVersion(Transaction txn, ContactId contactId,
+			ClientId clientId, int majorVersion) throws DbException;
+
 	interface ClientVersioningHook {
 
 		void onClientVisibilityChanging(Transaction txn, Contact c,
diff --git a/bramble-core/src/main/java/org/briarproject/bramble/versioning/ClientVersioningManagerImpl.java b/bramble-core/src/main/java/org/briarproject/bramble/versioning/ClientVersioningManagerImpl.java
index a7a6ac312..ccc7b41bb 100644
--- a/bramble-core/src/main/java/org/briarproject/bramble/versioning/ClientVersioningManagerImpl.java
+++ b/bramble-core/src/main/java/org/briarproject/bramble/versioning/ClientVersioningManagerImpl.java
@@ -89,14 +89,9 @@ class ClientVersioningManagerImpl implements ClientVersioningManager, Client,
 	public Visibility getClientVisibility(Transaction txn, ContactId contactId,
 			ClientId clientId, int majorVersion) throws DbException {
 		try {
-			Contact contact = db.getContact(txn, contactId);
-			Group g = getContactGroup(contact);
-			// Contact may be in the process of being added or removed, so
-			// contact group may not exist
-			if (!db.containsGroup(txn, g.getId())) return INVISIBLE;
-			LatestUpdates latest = findLatestUpdates(txn, g.getId());
+			LatestUpdates latest = findLatestUpdates(txn, contactId);
+			if (latest == null || latest.remote == null) return INVISIBLE;
 			if (latest.local == null) throw new DbException();
-			if (latest.remote == null) return INVISIBLE;
 			Update localUpdate = loadUpdate(txn, latest.local.messageId);
 			Update remoteUpdate = loadUpdate(txn, latest.remote.messageId);
 			Map<ClientMajorVersion, Visibility> visibilities =
@@ -110,6 +105,24 @@ class ClientVersioningManagerImpl implements ClientVersioningManager, Client,
 		}
 	}
 
+	@Override
+	public int getClientMinorVersion(Transaction txn, ContactId contactId,
+			ClientId clientId, int majorVersion) throws DbException {
+		try {
+			LatestUpdates latest = findLatestUpdates(txn, contactId);
+			if (latest == null || latest.remote == null) return -1;
+			Update remoteUpdate = loadUpdate(txn, latest.remote.messageId);
+			ClientMajorVersion cv =
+					new ClientMajorVersion(clientId, majorVersion);
+			for (ClientState remote : remoteUpdate.states) {
+				if (remote.majorVersion.equals(cv)) return remote.minorVersion;
+			}
+			return -1;
+		} catch (FormatException e) {
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public void createLocalState(Transaction txn) throws DbException {
 		if (db.containsGroup(txn, localGroup.getId())) return;
@@ -336,6 +349,17 @@ class ClientVersioningManagerImpl implements ClientVersioningManager, Client,
 				MAJOR_VERSION, c);
 	}
 
+	@Nullable
+	private LatestUpdates findLatestUpdates(Transaction txn, ContactId c)
+			throws DbException, FormatException {
+		Contact contact = db.getContact(txn, c);
+		Group g = getContactGroup(contact);
+		// Contact may be in the process of being added or removed, so
+		// contact group may not exist
+		if (!db.containsGroup(txn, g.getId())) return null;
+		return findLatestUpdates(txn, g.getId());
+	}
+
 	private LatestUpdates findLatestUpdates(Transaction txn, GroupId g)
 			throws DbException, FormatException {
 		Map<MessageId, BdfDictionary> metadata =