Add adaptive packet loss handling

tests/VoiceCat.Tests/ChannelManagementTests.cs

@@ -1,4 +1,5 @@
 using VoiceCat.Server.Data;
+using VoiceCat.Protocol;
 using Voicecat.V1;
 using static VoiceCat.Tests.ServerTests;
 
@@ -11,7 +12,8 @@ public class ChannelManagementTests
         using (var store = new AccountStore(Path.Combine(fixture.Directory, "voicecat.db")))
             await store.CreateAccountAsync("Admin", "secret", true);
         Client client = await fixture.ConnectAsync();
-        client.Send(new() { ClientHello = new() { ProtoVersion = 2 } });
+        var hello = new ClientHello { ProtoVersion = 2 }; hello.Features.Add(ProtocolFeatures.AdaptivePacketLoss);
+        client.Send(new() { ClientHello = hello });
         await client.ReadUntilAsync(e => e.ServerHello is not null);
         client.Send(new() { AuthRequest = new() { Password = new() { Username = "Admin", Password = "secret" } } });
         Assert.True((await client.ReadUntilAsync(e => e.AuthResult is not null)).AuthResult.Ok);
@@ -114,6 +116,7 @@ public class ChannelManagementTests
             music.Audio.Dtx = true;
             music.Audio.Fec = true;
             music.Audio.Dred = true;
+            music.Audio.PacketLossMode = PacketLossMode.PacketLossAutoStable;
             music.Audio.Complexity = 10;
             Assert.True(await ResultAsync(admin, new() { EditChannel = new() { Channel = music } }));
         }
@@ -126,6 +129,36 @@ public class ChannelManagementTests
         Assert.True(audio.Dtx);
         Assert.True(audio.Fec);
         Assert.True(audio.Dred);
+        Assert.Equal(PacketLossMode.PacketLossAutoStable, audio.PacketLossMode);
         Assert.Equal(10U, audio.Complexity);
     }
+
+    [Fact]
+    public async Task LegacyAdministratorEditsPreserveAutomaticPacketLossMode()
+    {
+        await using var fixture = new ServerFixture();
+        await using var current = await AdminAsync(fixture);
+        Channel music;
+        using (var store = new AccountStore(Path.Combine(fixture.Directory, "voicecat.db")))
+        {
+            music = store.LoadChannels().Single(channel => channel.Name == "Music Room");
+            music.Audio.PacketLossMode = PacketLossMode.PacketLossAutoBalanced;
+        }
+        Assert.True(await ResultAsync(current, new() { EditChannel = new() { Channel = music } }));
+
+        await using Client legacy = await fixture.ConnectAsync();
+        legacy.Send(new() { ClientHello = new() { ProtoVersion = 2 } });
+        await legacy.ReadUntilAsync(envelope => envelope.ServerHello is not null);
+        legacy.Send(new() { AuthRequest = new() { Password = new() { Username = "Admin", Password = "secret" } } });
+        Assert.True((await legacy.ReadUntilAsync(envelope => envelope.AuthResult is not null)).AuthResult.Ok);
+        await legacy.ReadUntilAsync(envelope => envelope.ServerState is not null);
+        music.Audio.PacketLossMode = PacketLossMode.PacketLossManual;
+        music.Audio.ExpectedPacketLoss = 23;
+        Assert.True(await ResultAsync(legacy, new() { EditChannel = new() { Channel = music } }));
+
+        using var verify = new AccountStore(Path.Combine(fixture.Directory, "voicecat.db"));
+        AudioConfig saved = verify.LoadChannels().Single(channel => channel.Id == music.Id).Audio;
+        Assert.Equal(PacketLossMode.PacketLossAutoBalanced, saved.PacketLossMode);
+        Assert.Equal(23U, saved.ExpectedPacketLoss);
+    }
 }