Add managed UIKit iOS client

clients/apple/dotnet/VoiceCat.iOS/AppDelegate.cs

@@ -0,0 +1,19 @@
+using Foundation;
+using UIKit;
+
+namespace VoiceCat.iOS;
+
+[Register("AppDelegate")]
+internal sealed class AppDelegate : UIApplicationDelegate
+{
+    public override bool FinishedLaunching(UIApplication application, NSDictionary? launchOptions)
+    {
+        AppModel.Shared.Load();
+        IosAudioRouter.Shared.Load();
+        return true;
+    }
+
+    public override UISceneConfiguration GetConfiguration(UIApplication application, UISceneSession connectingSceneSession,
+        UISceneConnectionOptions options) => new("Default Configuration", connectingSceneSession.Role)
+        { DelegateType = typeof(SceneDelegate) };
+}

clients/apple/dotnet/VoiceCat.iOS/AppModel.cs

@@ -0,0 +1,175 @@
+using UIKit;
+using VoiceCat.Audio;
+using VoiceCat.Core;
+using Voicecat.V1;
+using Channel = Voicecat.V1.Channel;
+
+namespace VoiceCat.iOS;
+
+internal sealed record ChatEntry(DateTime Timestamp, string Sender, string Text, bool Private);
+
+internal sealed class AppModel
+{
+    internal static AppModel Shared { get; } = new();
+    private readonly IosStorage storage = new();
+    private readonly List<ServerProfile> profiles = [];
+    private readonly List<ChatEntry> messages = [];
+    private CancellationTokenSource? lifetime;
+    private VoiceCatClient? client;
+    private TaskCompletionSource<bool>? identityDecision;
+    private ServerProfile? connectedProfile;
+    private int reconnectAttempt;
+    private bool explicitDisconnect;
+    private uint microphoneStream;
+    private BroadcastAudioPump? broadcast;
+
+    internal event Action? Changed;
+    internal event Action<ServerIdentityChallenge>? IdentityRequested;
+    internal IReadOnlyList<ServerProfile> Profiles => profiles;
+    internal IReadOnlyList<ChatEntry> Messages => messages;
+    internal VoiceCatClient? Client => client;
+    internal bool IsConnected => client?.State == ClientConnectionState.Connected;
+    internal bool IsConnecting { get; private set; }
+    internal bool VoiceJoined => microphoneStream != 0;
+    internal string Status { get; private set; } = "Not connected";
+    internal uint CurrentChannelId { get; private set; }
+    internal uint SelfUserId => client?.Authentication?.Self.Id ?? 0;
+    internal IReadOnlyList<Channel> Channels => client?.Channels ?? [];
+    internal IReadOnlyList<User> Users => client?.Users ?? [];
+
+    private AppModel() { }
+    internal void Load() { profiles.Clear(); profiles.AddRange(storage.LoadProfiles()); Notify(); }
+    internal void Save() => storage.SaveProfiles(profiles);
+
+    internal void UpsertProfile(ServerProfile profile, string? password)
+    {
+        int index = profiles.FindIndex(item => item.Id == profile.Id);
+        if (index < 0) profiles.Add(profile); else profiles[index] = profile;
+        if (!string.IsNullOrEmpty(password)) storage.SavePassword(profile.Id, password);
+        Save(); Notify();
+    }
+
+    internal void RemoveProfile(ServerProfile profile)
+    {
+        storage.RemovePassword(profile.Id); profiles.RemoveAll(item => item.Id == profile.Id); Save(); Notify();
+    }
+
+    internal async Task ConnectAsync(ServerProfile profile, string? suppliedPassword = null, bool restoring = false)
+    {
+        if (IsConnecting || IsConnected) return;
+        explicitDisconnect = false; IsConnecting = true; connectedProfile = profile;
+        Status = restoring ? "Reconnecting…" : "Connecting…"; Notify();
+        lifetime?.Cancel(); lifetime?.Dispose(); lifetime = new();
+        VoiceCatClient next = new("VoiceCat-iOS", "0.0.1", storage.TofuPath);
+        client = next;
+        try
+        {
+            await next.ConnectAsync(profile.Host, profile.Port, ConfirmIdentityAsync, lifetime.Token);
+            AuthResult auth = profile.Authentication == ServerAuthentication.Guest
+                ? await next.AuthenticateGuestAsync(profile.Nickname ?? "iOS User", lifetime.Token)
+                : await next.AuthenticateUserAsync(profile.Username!, suppliedPassword ?? storage.LoadPassword(profile) ?? "", lifetime.Token);
+            if (!auth.Ok) throw new InvalidOperationException(auth.Error);
+            CurrentChannelId = auth.Self.ChannelId; reconnectAttempt = 0; IsConnecting = false; Status = "Connected";
+            IosAudioEngine.Shared.StartListening(next);
+            broadcast = new(); broadcast.Start(next);
+            _ = PumpEventsAsync(next, lifetime.Token);
+            Notify();
+        }
+        catch (Exception exception)
+        {
+            IsConnecting = false; Status = exception.Message; Notify();
+            await next.DisposeAsync(); if (ReferenceEquals(client, next)) client = null;
+            if (restoring && !explicitDisconnect) ScheduleReconnect();
+            else throw;
+        }
+    }
+
+    private ValueTask<bool> ConfirmIdentityAsync(ServerIdentityChallenge challenge, CancellationToken token)
+    {
+        identityDecision = new(TaskCreationOptions.RunContinuationsAsynchronously);
+        token.Register(() => identityDecision.TrySetCanceled(token));
+        UIApplication.SharedApplication.BeginInvokeOnMainThread(() => IdentityRequested?.Invoke(challenge));
+        return new(identityDecision.Task);
+    }
+
+    internal void ResolveIdentity(bool accepted) { identityDecision?.TrySetResult(accepted); identityDecision = null; }
+
+    private async Task PumpEventsAsync(VoiceCatClient owner, CancellationToken token)
+    {
+        try
+        {
+            await foreach (Envelope envelope in owner.ReadEventsAsync(token))
+            {
+                if (envelope.JoinChannelResult?.Ok == true) CurrentChannelId = envelope.JoinChannelResult.ChannelId;
+                if (envelope.TextMessage is { } text)
+                {
+                    User? sender = owner.Users.FirstOrDefault(user => user.Id == text.SenderId);
+                    messages.Add(new(DateTime.Now, sender?.Nickname ?? $"User {text.SenderId}", text.Body, text.Scope == TextScope.TextPrivate));
+                    if (messages.Count > 500) messages.RemoveAt(0);
+                }
+                UIApplication.SharedApplication.BeginInvokeOnMainThread(Notify);
+            }
+        }
+        catch (OperationCanceledException) { }
+        finally
+        {
+            if (ReferenceEquals(client, owner) && !explicitDisconnect)
+            {
+                IosAudioEngine.Shared.Stop(); client = null; Status = "Connection lost"; UIApplication.SharedApplication.BeginInvokeOnMainThread(Notify);
+                ScheduleReconnect();
+            }
+        }
+    }
+
+    internal async Task JoinChannelAsync(uint channelId, string password = "")
+    {
+        VoiceCatClient active = client ?? throw new InvalidOperationException("Not connected.");
+        Envelope response = await active.RequestAsync(new() { JoinChannel = new() { ChannelId = channelId, Password = password } });
+        if (response.JoinChannelResult?.Ok != true) throw new InvalidOperationException(response.JoinChannelResult?.Error ?? "Join failed.");
+        CurrentChannelId = channelId; Notify();
+    }
+
+    internal void SendText(string body, uint targetUser = 0)
+    {
+        if (string.IsNullOrWhiteSpace(body)) return;
+        (client ?? throw new InvalidOperationException("Not connected.")).Send(new()
+        {
+            TextMessage = new() { Scope = targetUser == 0 ? TextScope.TextChannel : TextScope.TextPrivate,
+                TargetId = targetUser == 0 ? CurrentChannelId : targetUser, Body = body.Trim(), ClientMsgId = Guid.NewGuid().ToString("N") }
+        });
+    }
+
+    internal async Task ToggleVoiceAsync()
+    {
+        VoiceCatClient active = client ?? throw new InvalidOperationException("Not connected.");
+        if (microphoneStream != 0)
+        {
+            IosAudioEngine.Shared.StopMicrophone(); active.StopStream(microphoneStream); microphoneStream = 0;
+            await active.SubscribeVoiceAsync(false); Notify(); return;
+        }
+        if (AVFoundation.AVCaptureDevice.GetAuthorizationStatus(AVFoundation.AVAuthorizationMediaType.Audio) == AVFoundation.AVAuthorizationStatus.NotDetermined)
+            await AVFoundation.AVCaptureDevice.RequestAccessForMediaTypeAsync(AVFoundation.AVAuthorizationMediaType.Audio);
+        VoiceSubscriptionResult subscribed = await active.SubscribeVoiceAsync();
+        if (!subscribed.Ok) throw new InvalidOperationException(subscribed.Error);
+        int channels = IosAudioRouter.Shared.CaptureChannels;
+        StreamInfo stream = await active.StartStreamAsync(StreamKind.StreamMic, "Microphone", channels);
+        microphoneStream = stream.StreamId; IosAudioEngine.Shared.StartMicrophone(stream.StreamId, channels); Notify();
+    }
+
+    internal async Task DisconnectAsync()
+    {
+        explicitDisconnect = true; lifetime?.Cancel(); IosAudioEngine.Shared.Stop();
+        if (broadcast is { } pump) { broadcast = null; await pump.DisposeAsync(); }
+        VoiceCatClient? old = client; client = null; microphoneStream = 0; IsConnecting = false; Status = "Not connected"; Notify();
+        if (old is not null) await old.DisposeAsync();
+    }
+
+    private void ScheduleReconnect()
+    {
+        ServerProfile? profile = connectedProfile; if (profile is null || explicitDisconnect) return;
+        int delay = Math.Min(1 << Math.Min(reconnectAttempt++, 5), 30);
+        _ = Task.Run(async () => { try { await Task.Delay(TimeSpan.FromSeconds(delay), lifetime?.Token ?? default); await ConnectAsync(profile, restoring: true); } catch { } });
+    }
+
+    private void Notify() => Changed?.Invoke();
+}

clients/apple/dotnet/VoiceCat.iOS/BroadcastAudioPump.cs

@@ -0,0 +1,70 @@
+using System.IO.MemoryMappedFiles;
+using VoiceCat.Core;
+using Voicecat.V1;
+
+namespace VoiceCat.iOS;
+
+internal sealed class BroadcastAudioPump : IAsyncDisposable
+{
+    private const uint Magic = 0x56434252, Version = 1;
+    private const int Header = 64, Capacity = 96_000, Frame = 960;
+    private readonly CancellationTokenSource stop = new();
+    private Task worker = Task.CompletedTask;
+    private VoiceCatClient? client;
+    private uint streamId;
+    private readonly short[] scratch = new short[Frame * 2];
+
+    internal void Start(VoiceCatClient owner) { client = owner; worker = RunAsync(stop.Token); }
+
+    private async Task RunAsync(CancellationToken token)
+    {
+        while (!token.IsCancellationRequested)
+        {
+            try { await DrainAsync(token); }
+            catch (Exception exception) when (exception is IOException or UnauthorizedAccessException or InvalidDataException) { }
+            await Task.Delay(10, token).ConfigureAwait(false);
+        }
+    }
+
+    private async Task DrainAsync(CancellationToken token)
+    {
+        NSUrl? root = NSFileManager.DefaultManager.GetContainerUrl(IosConstants.AppGroup);
+        if (root?.Path is null) return;
+        string path = Path.Combine(root.Path, "voicecat", "broadcast_audio.ring"); if (!File.Exists(path)) return;
+        using MemoryMappedFile map = MemoryMappedFile.CreateFromFile(path, FileMode.Open, null, Header + Capacity * sizeof(short), MemoryMappedFileAccess.ReadWrite);
+        using MemoryMappedViewAccessor view = map.CreateViewAccessor(0, Header + Capacity * sizeof(short), MemoryMappedFileAccess.ReadWrite);
+        if (view.ReadUInt32(0) != Magic || view.ReadUInt32(4) != Version) throw new InvalidDataException("Unsupported broadcast ring.");
+        bool active = view.ReadUInt32(16) != 0;
+        if (!active) { StopStream(); return; }
+        VoiceCatClient owner = client ?? throw new IOException("Client disconnected.");
+        if (streamId == 0)
+        {
+            StreamInfo stream = await owner.StartStreamAsync(StreamKind.StreamScreenAudio, "Screen audio", 2, token).ConfigureAwait(false);
+            streamId = stream.StreamId; view.Write(32, view.ReadUInt64(24));
+        }
+        ulong write = view.ReadUInt64(24), read = view.ReadUInt64(32);
+        if (write - read > Capacity) read = write - Capacity;
+        while (write - read >= Frame * 2)
+        {
+            for (int sample = 0; sample < scratch.Length; sample++)
+            {
+                ulong index = (read + (ulong)sample) % Capacity;
+                scratch[sample] = view.ReadInt16(Header + checked((long)index * sizeof(short)));
+            }
+            if (!owner.Audio.FeedPcm(streamId, scratch, 2)) break;
+            read += (ulong)scratch.Length;
+            view.Write(32, read);
+        }
+    }
+
+    private void StopStream()
+    {
+        uint id = streamId; streamId = 0; if (id == 0 || client?.State != ClientConnectionState.Connected) return;
+        try { client.StopStream(id); } catch (Exception exception) when (exception is IOException or InvalidOperationException) { }
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        stop.Cancel(); try { await worker.ConfigureAwait(false); } catch (OperationCanceledException) { } StopStream(); stop.Dispose();
+    }
+}

clients/apple/dotnet/VoiceCat.iOS/Entitlements.plist

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0"><dict>
+  <key>com.apple.security.application-groups</key><array><string>group.me.iamtalon.voicecat</string></array>
+</dict></plist>

clients/apple/dotnet/VoiceCat.iOS/Info.plist

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0"><dict>
+  <key>CFBundleDisplayName</key><string>VoiceCat</string>
+  <key>CFBundleIdentifier</key><string>me.iamtalon.voicecat</string>
+  <key>CFBundleShortVersionString</key><string>0.0.1</string>
+  <key>CFBundleVersion</key><string>1</string>
+  <key>LSRequiresIPhoneOS</key><true/>
+  <key>NSMicrophoneUsageDescription</key><string>VoiceCat needs microphone access to transmit your voice in channels.</string>
+  <key>UIBackgroundModes</key><array><string>audio</string></array>
+  <key>UIRequiresFullScreen</key><false/>
+  <key>UIDeviceFamily</key><array><integer>1</integer><integer>2</integer></array>
+  <key>UILaunchScreen</key><dict/>
+  <key>UISupportedInterfaceOrientations</key><array><string>UIInterfaceOrientationPortrait</string><string>UIInterfaceOrientationLandscapeLeft</string><string>UIInterfaceOrientationLandscapeRight</string></array>
+  <key>UISupportedInterfaceOrientations~ipad</key><array><string>UIInterfaceOrientationPortrait</string><string>UIInterfaceOrientationPortraitUpsideDown</string><string>UIInterfaceOrientationLandscapeLeft</string><string>UIInterfaceOrientationLandscapeRight</string></array>
+  <key>UIApplicationSceneManifest</key><dict>
+    <key>UIApplicationSupportsMultipleScenes</key><false/>
+    <key>UISceneConfigurations</key><dict><key>UIWindowSceneSessionRoleApplication</key><array><dict>
+      <key>UISceneConfigurationName</key><string>Default Configuration</string>
+      <key>UISceneDelegateClassName</key><string>VoiceCat.iOS.SceneDelegate</string>
+    </dict></array></dict>
+  </dict>
+</dict></plist>

clients/apple/dotnet/VoiceCat.iOS/IosAudioEngine.cs

@@ -0,0 +1,157 @@
+using System.Runtime.InteropServices;
+using AVFoundation;
+using VoiceCat.Audio;
+using VoiceCat.Core;
+
+namespace VoiceCat.iOS;
+
+internal sealed class IosAudioEngine
+{
+    internal static IosAudioEngine Shared { get; } = new();
+    private readonly PcmRing playbackRing = new(131_072);
+    private readonly short[] renderScratch = new short[16_384];
+    private AVAudioEngine? engine;
+    private AVAudioSourceNode? source;
+    private AVAudioFormat? outputFormat;
+    private VoiceCatClient? client;
+    private uint microphoneStream;
+    private int microphoneChannels = 1;
+    private readonly PcmRing microphoneRing = new(131_072);
+    private readonly short[] microphoneFrame = new short[960 * 2];
+    private readonly CancellationTokenSource microphoneStop = new();
+    private readonly Task microphoneWorker;
+    private AVAudioFormat? microphoneFormat;
+    private AVAudioConverter? microphoneConverter;
+    private AVAudioPcmBuffer? convertedMicrophone;
+    private AVAudioPcmBuffer? pendingInput;
+    private AVAudioConverterInputHandler? inputProvider;
+    private bool inputProvided;
+    private bool tapInstalled;
+    internal bool IsConnected { get; private set; }
+
+    private IosAudioEngine() { microphoneWorker = PumpMicrophoneAsync(microphoneStop.Token); }
+
+    internal void StartListening(VoiceCatClient owner)
+    {
+        Stop(); client = owner; IsConnected = true; owner.Audio.MixedPcm += ReceiveMixedPcm; Rebuild();
+    }
+
+    internal void StartMicrophone(uint streamId, int channels)
+    {
+        microphoneStream = streamId; microphoneChannels = Math.Clamp(channels, 1, 2); Rebuild();
+    }
+
+    internal void StopMicrophone() { microphoneStream = 0; Rebuild(); }
+    internal void Reconfigure() { if (IsConnected) Rebuild(); }
+
+    private void Rebuild()
+    {
+        DestroyGraph(); IosAudioRouter.Shared.Apply();
+        var next = new AVAudioEngine();
+        outputFormat = new(AVAudioCommonFormat.PCMFloat32, 48_000, 2, false);
+        source = new(outputFormat, Render);
+        next.AttachNode(source);
+        NSError? connectionError = null;
+        if (OperatingSystem.IsIOSVersionAtLeast(27)) next.Connect(source, next.MainMixerNode, outputFormat, out connectionError);
+        else next.Connect(source, next.MainMixerNode, outputFormat);
+        if (connectionError is not null) throw new InvalidOperationException(connectionError.LocalizedDescription);
+        if (microphoneStream != 0)
+        {
+            AVAudioInputNode input = next.InputNode;
+            input.SetVoiceProcessingEnabled(IosAudioRouter.Shared.UsesVoiceProcessing, out _);
+            if (IosAudioRouter.Shared.UsesVoiceProcessing) input.VoiceProcessingAgcEnabled = IosAudioRouter.Shared.AutomaticGainControl;
+            AVAudioFormat inputFormat = input.GetBusOutputFormat(0);
+            microphoneFormat = new(AVAudioCommonFormat.PCMInt16, 48_000, (uint)microphoneChannels, true);
+            microphoneConverter = new(inputFormat, microphoneFormat);
+            uint capacity = checked((uint)Math.Ceiling(4_096 * 48_000 / inputFormat.SampleRate) + 64);
+            convertedMicrophone = new(microphoneFormat, capacity);
+            inputProvider = ProvideInput;
+            NSError? tapError = null;
+            if (OperatingSystem.IsIOSVersionAtLeast(27)) input.InstallTapOnBus(0, 960, inputFormat, out tapError, Capture);
+            else input.InstallTapOnBus(0, 960, inputFormat, Capture);
+            if (tapError is not null) throw new InvalidOperationException(tapError.LocalizedDescription);
+            tapInstalled = true;
+        }
+        next.Prepare();
+        if (!next.StartAndReturnError(out NSError? error)) { next.Dispose(); throw new InvalidOperationException(error.LocalizedDescription); }
+        engine = next;
+    }
+
+    private unsafe void Capture(AVAudioPcmBuffer buffer, AVAudioTime time)
+    {
+        VoiceCatClient? owner = client; uint stream = microphoneStream;
+        if (owner is null || stream == 0 || buffer.FrameLength == 0) return;
+        AVAudioConverter? converter = microphoneConverter;
+        AVAudioPcmBuffer? converted = convertedMicrophone;
+        AVAudioConverterInputHandler? provider = inputProvider;
+        if (converter is null || converted is null || provider is null) return;
+        pendingInput = buffer; inputProvided = false; converted.FrameLength = 0;
+        converter.ConvertToBuffer(converted, out _, provider);
+        if (converted.FrameLength == 0) return;
+        nint samples = Marshal.ReadIntPtr(converted.Int16ChannelData);
+        if (samples != 0) microphoneRing.TryWrite(new ReadOnlySpan<short>((void*)samples, checked((int)converted.FrameLength * microphoneChannels)));
+        pendingInput = null;
+    }
+
+    private AVAudioBuffer ProvideInput(uint _, out AVAudioConverterInputStatus status)
+    {
+        if (!inputProvided && pendingInput is { } input) { inputProvided = true; status = AVAudioConverterInputStatus.HaveData; return input; }
+        status = AVAudioConverterInputStatus.NoDataNow; return null!;
+    }
+
+    private async Task PumpMicrophoneAsync(CancellationToken token)
+    {
+        using var timer = new PeriodicTimer(TimeSpan.FromMilliseconds(10));
+        while (await timer.WaitForNextTickAsync(token).ConfigureAwait(false))
+        {
+            int channels = microphoneChannels, required = 960 * channels;
+            while (microphoneRing.Count >= required)
+            {
+                int read = microphoneRing.Read(microphoneFrame.AsSpan(0, required));
+                VoiceCatClient? owner = client; uint stream = microphoneStream;
+                if (read == required && owner is not null && stream != 0) owner.Audio.FeedPcm(stream, microphoneFrame.AsSpan(0, required), channels);
+            }
+        }
+    }
+
+    private void ReceiveMixedPcm(ReadOnlySpan<short> pcm) => playbackRing.TryWrite(pcm);
+
+    private unsafe int Render(IntPtr isSilence, IntPtr timestamp, uint frameCount, IntPtr outputData)
+    {
+        int frames = checked((int)frameCount), requested = checked(frames * 2);
+        if (requested > renderScratch.Length) return -1;
+        Span<short> input = renderScratch.AsSpan(0, requested);
+        int read = playbackRing.Read(input); input[read..].Clear();
+        int count = Marshal.ReadInt32(outputData), first = IntPtr.Size == 8 ? 8 : 4, stride = IntPtr.Size == 8 ? 16 : 12;
+        if (count != 2) return -1;
+        for (int channel = 0; channel < 2; channel++)
+        {
+            nint data = Marshal.ReadIntPtr(outputData, first + channel * stride + 8);
+            var output = new Span<float>((void*)data, frames);
+            for (int frame = 0; frame < frames; frame++) output[frame] = input[frame * 2 + channel] / 32768f;
+        }
+        if (isSilence != IntPtr.Zero) Marshal.WriteByte(isSilence, read == 0 ? (byte)1 : (byte)0);
+        return 0;
+    }
+
+    internal void Stop()
+    {
+        IsConnected = false; microphoneStream = 0;
+        if (client is { } owner) owner.Audio.MixedPcm -= ReceiveMixedPcm;
+        DestroyGraph(); client = null; IosAudioRouter.Shared.Deactivate();
+    }
+
+    private void DestroyGraph()
+    {
+        if (engine is { } old)
+        {
+            if (tapInstalled) old.InputNode.RemoveTapOnBus(0);
+            old.Stop(); if (source is not null) old.DetachNode(source); old.Dispose();
+        }
+        tapInstalled = false; pendingInput = null; inputProvider = null;
+        convertedMicrophone?.Dispose(); convertedMicrophone = null;
+        microphoneConverter?.Dispose(); microphoneConverter = null;
+        microphoneFormat?.Dispose(); microphoneFormat = null;
+        source?.Dispose(); source = null; outputFormat?.Dispose(); outputFormat = null; engine = null;
+    }
+}

clients/apple/dotnet/VoiceCat.iOS/IosAudioRouter.cs

@@ -0,0 +1,63 @@
+using AVFoundation;
+using Foundation;
+
+namespace VoiceCat.iOS;
+
+internal enum IosAudioPreset { VoiceChat, StereoMicrophone, MonoMicrophone, Advanced }
+
+internal sealed class IosAudioRouter
+{
+    internal static IosAudioRouter Shared { get; } = new();
+    private readonly NSUserDefaults defaults = NSUserDefaults.StandardUserDefaults;
+    internal IosAudioPreset Preset { get; private set; } = IosAudioPreset.VoiceChat;
+    internal bool ForceSpeaker { get; set; }
+    internal bool VoiceProcessing { get; set; } = true;
+    internal bool AutomaticGainControl { get; set; } = true;
+    internal int CaptureChannels => Preset == IosAudioPreset.StereoMicrophone ? 2 : 1;
+    internal bool UsesVoiceProcessing => VoiceProcessing && CaptureChannels == 1 && Preset != IosAudioPreset.MonoMicrophone;
+
+    private IosAudioRouter()
+    {
+        NSNotificationCenter.DefaultCenter.AddObserver(AVAudioSession.RouteChangeNotification, _ => Recover());
+        NSNotificationCenter.DefaultCenter.AddObserver(AVAudioSession.InterruptionNotification, note => HandleInterruption(note));
+        NSNotificationCenter.DefaultCenter.AddObserver(AVAudioSession.MediaServicesWereResetNotification, _ => Recover());
+    }
+
+    internal void Load()
+    {
+        string? preset = defaults.StringForKey("cat.voice.audio.preset");
+        if (Enum.TryParse(preset, true, out IosAudioPreset value)) Preset = value;
+        ForceSpeaker = defaults.BoolForKey("cat.voice.audio.forceSpeaker");
+        VoiceProcessing = defaults.ValueForKey(new NSString("cat.voice.audio.voiceProcessing")) is null || defaults.BoolForKey("cat.voice.audio.voiceProcessing");
+        AutomaticGainControl = defaults.ValueForKey(new NSString("cat.voice.audio.agc")) is null || defaults.BoolForKey("cat.voice.audio.agc");
+    }
+
+    internal void SelectPreset(IosAudioPreset preset)
+    {
+        Preset = preset; defaults.SetString(preset.ToString(), "cat.voice.audio.preset"); defaults.Synchronize();
+        if (IosAudioEngine.Shared.IsConnected) IosAudioEngine.Shared.Reconfigure();
+    }
+
+    internal void Apply()
+    {
+        AVAudioSession session = AVAudioSession.SharedInstance();
+        AVAudioSessionCategoryOptions options = AVAudioSessionCategoryOptions.AllowBluetooth;
+        if (Preset is IosAudioPreset.StereoMicrophone or IosAudioPreset.MonoMicrophone)
+            options = AVAudioSessionCategoryOptions.AllowBluetoothA2DP | AVAudioSessionCategoryOptions.DefaultToSpeaker;
+        if (!session.SetCategory(AVAudioSessionCategory.PlayAndRecord, AVAudioSessionMode.Default, options, out NSError? categoryError))
+            throw new InvalidOperationException(categoryError.LocalizedDescription);
+        session.SetPreferredSampleRate(48_000, out _);
+        session.SetPreferredIOBufferDuration(0.02, out _);
+        if (!session.SetActive(true, AVAudioSessionSetActiveOptions.NotifyOthersOnDeactivation, out NSError? activeError))
+            throw new InvalidOperationException(activeError.LocalizedDescription);
+        session.OverrideOutputAudioPort(ForceSpeaker ? AVAudioSessionPortOverride.Speaker : AVAudioSessionPortOverride.None, out _);
+    }
+
+    internal void Deactivate() => AVAudioSession.SharedInstance().SetActive(false, AVAudioSessionSetActiveOptions.NotifyOthersOnDeactivation, out _);
+    private void Recover() { if (IosAudioEngine.Shared.IsConnected) UIApplication.SharedApplication.BeginInvokeOnMainThread(IosAudioEngine.Shared.Reconfigure); }
+    private void HandleInterruption(NSNotification note)
+    {
+        NSNumber? type = note.UserInfo?[new NSString("AVAudioSessionInterruptionTypeKey")] as NSNumber;
+        if ((AVAudioSessionInterruptionType)(type?.UInt32Value ?? 0) == AVAudioSessionInterruptionType.Ended) Recover();
+    }
+}

clients/apple/dotnet/VoiceCat.iOS/IosConstants.cs

@@ -0,0 +1,8 @@
+namespace VoiceCat.iOS;
+
+internal static class IosConstants
+{
+    internal const string AppGroup = "group.me.iamtalon.voicecat";
+    internal const string BroadcastExtension = "me.iamtalon.voicecat.broadcast";
+    internal const string PasswordService = "me.iamtalon.voicecat.ios";
+}

clients/apple/dotnet/VoiceCat.iOS/IosStorage.cs

@@ -0,0 +1,90 @@
+using System.Security.Cryptography;
+using System.Text;
+using Foundation;
+using Security;
+using VoiceCat.Core;
+
+namespace VoiceCat.iOS;
+
+internal sealed class IosStorage
+{
+    private readonly string directory;
+    private readonly ServerProfileStore profiles;
+
+    internal IosStorage()
+    {
+        NSUrl? group = NSFileManager.DefaultManager.GetContainerUrl(IosConstants.AppGroup);
+        string root = group?.Path ?? Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+        directory = Path.Combine(root, "voicecat");
+        profiles = new(Path.Combine(directory, "servers.json"));
+    }
+
+    internal string TofuPath => Path.Combine(directory, "tofu_pins.txt");
+    internal IReadOnlyList<ServerProfile> LoadProfiles()
+    {
+        MigrateLegacyFiles();
+        return profiles.Load();
+    }
+    internal void SaveProfiles(IEnumerable<ServerProfile> values) => profiles.Save(values);
+
+    private void MigrateLegacyFiles()
+    {
+        Directory.CreateDirectory(directory);
+        string legacy = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "voicecat");
+        if (Path.GetFullPath(legacy) == Path.GetFullPath(directory) || !Directory.Exists(legacy)) return;
+        foreach (string name in new[] { "servers.json", "tofu_pins.txt" })
+        {
+            string source = Path.Combine(legacy, name), destination = Path.Combine(directory, name);
+            if (File.Exists(source) && !File.Exists(destination)) File.Copy(source, destination);
+        }
+    }
+
+    internal string? LoadPassword(ServerProfile profile)
+    {
+        string? value = ReadPassword(IosConstants.PasswordService, profile.Id.ToString("D"), IosConstants.AppGroup);
+        return value ?? (profile.LegacyKeychainTag is { Length: > 0 } tag
+            ? ReadPassword("cat.voice.VoiceCatiOS", tag, IosConstants.AppGroup) ?? ReadPassword("cat.voice.VoiceCatiOS", tag, null)
+            : null);
+    }
+
+    internal void SavePassword(Guid id, string password)
+    {
+        byte[] encoded = Encoding.UTF8.GetBytes(password);
+        try
+        {
+            using var data = NSData.FromArray(encoded);
+            using var query = PasswordQuery(IosConstants.PasswordService, id.ToString("D"), IosConstants.AppGroup);
+            using var attributes = new SecRecord { ValueData = data, Label = "VoiceCat server password", Accessible = SecAccessible.AfterFirstUnlock };
+            SecStatusCode status = SecKeyChain.Update(query, attributes);
+            if (status == SecStatusCode.ItemNotFound)
+            {
+                using var record = PasswordQuery(IosConstants.PasswordService, id.ToString("D"), IosConstants.AppGroup);
+                record.ValueData = data; record.Label = attributes.Label; record.Accessible = attributes.Accessible;
+                status = SecKeyChain.Add(record);
+            }
+            if (status != SecStatusCode.Success) throw new InvalidOperationException($"Keychain save failed ({status}).");
+        }
+        finally { CryptographicOperations.ZeroMemory(encoded); }
+    }
+
+    internal void RemovePassword(Guid id)
+    {
+        using var query = PasswordQuery(IosConstants.PasswordService, id.ToString("D"), IosConstants.AppGroup);
+        SecStatusCode status = SecKeyChain.Remove(query);
+        if (status is not (SecStatusCode.Success or SecStatusCode.ItemNotFound))
+            throw new InvalidOperationException($"Keychain removal failed ({status}).");
+    }
+
+    private static string? ReadPassword(string service, string account, string? group)
+    {
+        using var query = PasswordQuery(service, account, group);
+        using SecRecord? result = SecKeyChain.QueryAsRecord(query, out SecStatusCode status);
+        if (status != SecStatusCode.Success || result?.ValueData is not { } data) return null;
+        byte[] bytes = data.ToArray();
+        try { return Encoding.UTF8.GetString(bytes); }
+        finally { CryptographicOperations.ZeroMemory(bytes); }
+    }
+
+    private static SecRecord PasswordQuery(string service, string account, string? group) => new(SecKind.GenericPassword)
+    { Service = service, Account = account, AccessGroup = group };
+}

clients/apple/dotnet/VoiceCat.iOS/Main.cs

@@ -0,0 +1,3 @@
+using UIKit;
+
+UIApplication.Main(args, null, typeof(VoiceCat.iOS.AppDelegate));

clients/apple/dotnet/VoiceCat.iOS/MainControllers.cs

@@ -0,0 +1,128 @@
+using ReplayKit;
+using UIKit;
+using Voicecat.V1;
+using Channel = Voicecat.V1.Channel;
+
+namespace VoiceCat.iOS;
+
+internal sealed class MainTabController : UITabBarController
+{
+    internal MainTabController(AppModel model)
+    {
+        UIViewController channels = new UINavigationController(new ChannelsController(model));
+        channels.TabBarItem = new("Channels", UIImage.GetSystemImage("list.bullet.indent"), 0);
+        UIViewController chat = new UINavigationController(new ChatController(model));
+        chat.TabBarItem = new("Chat", UIImage.GetSystemImage("message"), 1);
+        UIViewController settings = new UINavigationController(new SettingsController(model));
+        settings.TabBarItem = new("Settings", UIImage.GetSystemImage("gear"), 2);
+        ViewControllers = [channels, chat, settings];
+    }
+}
+
+internal sealed class ChannelsController : UITableViewController
+{
+    private readonly AppModel model;
+    internal ChannelsController(AppModel model) { this.model = model; Title = "Channels"; model.Changed += () => TableView.ReloadData(); }
+    public override void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "channel"); NavigationItem.RightBarButtonItem = new("Users", UIBarButtonItemStyle.Plain, (_, _) => NavigationController?.PushViewController(new UsersController(model), true)); }
+    public override nint RowsInSection(UITableView tableView, nint section) => model.Channels.Count;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath)
+    {
+        Channel channel = model.Channels.OrderBy(c => c.Order).ThenBy(c => c.Name).ElementAt(indexPath.Row);
+        UITableViewCell cell = tableView.DequeueReusableCell("channel", indexPath); int count = model.Users.Count(u => u.ChannelId == channel.Id);
+        var content = cell.DefaultContentConfiguration; content.Text = channel.Name; content.SecondaryText = $"{count} users" + (channel.PasswordProtected ? " • protected" : ""); content.Image = UIImage.GetSystemImage(channel.Id == model.CurrentChannelId ? "checkmark.circle.fill" : "bubble.left"); cell.ContentConfiguration = content; cell.AccessibilityLabel = $"{channel.Name}, {count} users"; return cell;
+    }
+    public override async void RowSelected(UITableView tableView, NSIndexPath indexPath)
+    {
+        Channel channel = model.Channels.OrderBy(c => c.Order).ThenBy(c => c.Name).ElementAt(indexPath.Row); tableView.DeselectRow(indexPath, true);
+        if (channel.PasswordProtected)
+        {
+            UIAlertController prompt = UIAlertController.Create("Channel Password", channel.Name, UIAlertControllerStyle.Alert); prompt.AddTextField(f => { f.SecureTextEntry = true; f.Placeholder = "Password"; });
+            prompt.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null)); prompt.AddAction(UIAlertAction.Create("Join", UIAlertActionStyle.Default, async _ => { try { await model.JoinChannelAsync(channel.Id, prompt.TextFields![0].Text ?? ""); } catch (Exception e) { UiHelpers.ShowError(this, e); } })); PresentViewController(prompt, true, null); return;
+        }
+        try { await model.JoinChannelAsync(channel.Id); } catch (Exception e) { UiHelpers.ShowError(this, e); }
+    }
+}
+
+internal sealed class UsersController : UITableViewController
+{
+    private readonly AppModel model;
+    private IReadOnlyList<User> Visible => model.Users.Where(u => u.ChannelId == model.CurrentChannelId).ToArray();
+    internal UsersController(AppModel model) { this.model = model; Title = "Users"; model.Changed += () => TableView.ReloadData(); }
+    public override void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "user"); }
+    public override nint RowsInSection(UITableView tableView, nint section) => Visible.Count;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath)
+    {
+        User user = Visible[indexPath.Row]; UITableViewCell cell = tableView.DequeueReusableCell("user", indexPath);
+        var content = cell.DefaultContentConfiguration; content.Text = user.Nickname + (user.Id == model.SelfUserId ? " (you)" : ""); content.SecondaryText = user.ServerMuted ? "server muted" : user.SelfMicMuted ? "muted" : user.IsGuest ? "guest" : "account"; content.Image = UIImage.GetSystemImage(user.ServerMuted || user.SelfMicMuted ? "mic.slash.fill" : "mic.fill"); cell.ContentConfiguration = content; cell.AccessibilityLabel = $"{content.Text}, {content.SecondaryText}"; return cell;
+    }
+    public override void RowSelected(UITableView tableView, NSIndexPath indexPath)
+    {
+        User user = Visible[indexPath.Row]; tableView.DeselectRow(indexPath, true); if (user.Id == model.SelfUserId) return;
+        UIAlertController menu = UIAlertController.Create(user.Nickname, null, UIAlertControllerStyle.ActionSheet);
+        menu.AddAction(UIAlertAction.Create("Private message", UIAlertActionStyle.Default, _ => PromptPrivate(user)));
+        if (model.Client?.Permissions.CanKick == true || model.Client?.Permissions.IsAdmin == true) menu.AddAction(UIAlertAction.Create("Kick", UIAlertActionStyle.Destructive, async _ => await Run(() => model.Client!.KickUserAsync(user.Id))));
+        if (model.Client?.Permissions.CanBan == true || model.Client?.Permissions.IsAdmin == true) menu.AddAction(UIAlertAction.Create("Ban", UIAlertActionStyle.Destructive, async _ => await Run(() => model.Client!.BanUserAsync(user.Id))));
+        if (model.Client?.Permissions.IsAdmin == true) menu.AddAction(UIAlertAction.Create(user.ServerMuted ? "Server unmute" : "Server mute", UIAlertActionStyle.Default, async _ => await Run(() => model.Client!.SetServerMuteAsync(user.Id, !user.ServerMuted, user.ServerDeafened))));
+        menu.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null)); menu.PopoverPresentationController!.SourceView = tableView.CellAt(indexPath); PresentViewController(menu, true, null);
+    }
+    private void PromptPrivate(User user) { UIAlertController p = UIAlertController.Create($"Message {user.Nickname}", null, UIAlertControllerStyle.Alert); p.AddTextField(f => f.Placeholder = "Message"); p.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null)); p.AddAction(UIAlertAction.Create("Send", UIAlertActionStyle.Default, _ => model.SendText(p.TextFields![0].Text ?? "", user.Id))); PresentViewController(p, true, null); }
+    private async Task Run(Func<Task<GenericResult>> command) { try { GenericResult result = await command(); if (!result.Ok) throw new InvalidOperationException(result.Message); } catch (Exception e) { UiHelpers.ShowError(this, e); } }
+}
+
+internal sealed class ChatController : UIViewController
+{
+    private readonly AppModel model; private readonly UITextView log = new(); private readonly UITextField compose = UiHelpers.Field("Message");
+    internal ChatController(AppModel model) { this.model = model; Title = "Chat"; model.Changed += Refresh; }
+    public override void ViewDidLoad()
+    {
+        base.ViewDidLoad(); View!.BackgroundColor = UIColor.SystemBackground; log.Editable = false; log.Font = UIFont.PreferredBody; log.TranslatesAutoresizingMaskIntoConstraints = false;
+        UIButton send = UIButton.FromType(UIButtonType.System); send.SetTitle("Send", UIControlState.Normal); send.AccessibilityLabel = "Send message"; send.TranslatesAutoresizingMaskIntoConstraints = false; send.TouchUpInside += (_, _) => { model.SendText(compose.Text ?? ""); compose.Text = ""; };
+        compose.TranslatesAutoresizingMaskIntoConstraints = false; View.AddSubviews(log, compose, send);
+        NSLayoutConstraint.ActivateConstraints([log.TopAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.TopAnchor), log.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor, 12), log.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor, -12), compose.TopAnchor.ConstraintEqualTo(log.BottomAnchor, 8), compose.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor, 12), compose.BottomAnchor.ConstraintEqualTo(View.KeyboardLayoutGuide.TopAnchor, -8), send.LeadingAnchor.ConstraintEqualTo(compose.TrailingAnchor, 8), send.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor, -12), send.CenterYAnchor.ConstraintEqualTo(compose.CenterYAnchor), compose.WidthAnchor.ConstraintGreaterThanOrEqualTo(120)]); Refresh();
+    }
+    private void Refresh() { log.Text = string.Join("\n", model.Messages.Select(m => $"[{m.Timestamp:t}] {(m.Private ? "[private] " : "")}{m.Sender}: {m.Text}")); if (log.Text.Length > 0) log.ScrollRangeToVisible(new(log.Text.Length - 1, 1)); }
+}
+
+internal sealed class SettingsController : UITableViewController
+{
+    private readonly AppModel model; private readonly string[] rows = ["Join Voice", "Audio Preset", "Speaker Output", "Mute Microphone", "Deafen", "Share Screen Audio", "Accounts", "Disconnect"];
+    internal SettingsController(AppModel model) : base(UITableViewStyle.InsetGrouped) { this.model = model; Title = "Settings"; model.Changed += () => TableView.ReloadData(); }
+    public override void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "setting"); }
+    public override nint RowsInSection(UITableView tableView, nint section) => rows.Length;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath)
+    {
+        UITableViewCell cell = tableView.DequeueReusableCell("setting", indexPath); string title = rows[indexPath.Row];
+        if (indexPath.Row == 0) title = model.VoiceJoined ? "Leave Voice" : "Join Voice";
+        var content = cell.DefaultContentConfiguration; content.Text = title; content.SecondaryText = indexPath.Row == 1 ? IosAudioRouter.Shared.Preset.ToString() : null; cell.ContentConfiguration = content; cell.Accessory = indexPath.Row is 1 or 6 ? UITableViewCellAccessory.DisclosureIndicator : UITableViewCellAccessory.None; return cell;
+    }
+    public override async void RowSelected(UITableView tableView, NSIndexPath indexPath)
+    {
+        tableView.DeselectRow(indexPath, true); try
+        {
+            switch (indexPath.Row)
+            {
+                case 0: await model.ToggleVoiceAsync(); break;
+                case 1: ShowPresets(); break;
+                case 2: IosAudioRouter.Shared.ForceSpeaker = !IosAudioRouter.Shared.ForceSpeaker; IosAudioEngine.Shared.Reconfigure(); break;
+                case 3: if (model.Client is { } c) c.SetSelfAudioState(!c.Audio.MicMuted, c.Audio.Deafened); break;
+                case 4: if (model.Client is { } d) d.SetSelfAudioState(d.Audio.MicMuted, !d.Audio.Deafened); break;
+                case 5: ShowBroadcastPicker(); break;
+                case 6: NavigationController?.PushViewController(new AccountsController(model), true); break;
+                case 7: await model.DisconnectAsync(); break;
+            }
+        }
+        catch (Exception e) { UiHelpers.ShowError(this, e); }
+    }
+    private void ShowPresets() { UIAlertController a = UIAlertController.Create("Audio Preset", null, UIAlertControllerStyle.ActionSheet); foreach (IosAudioPreset p in Enum.GetValues<IosAudioPreset>()) a.AddAction(UIAlertAction.Create(p.ToString(), UIAlertActionStyle.Default, _ => { IosAudioRouter.Shared.SelectPreset(p); TableView.ReloadData(); })); a.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null)); a.PopoverPresentationController!.SourceView = View; PresentViewController(a, true, null); }
+    private void ShowBroadcastPicker() { var picker = new RPSystemBroadcastPickerView(new CoreGraphics.CGRect(0, 0, 60, 60)) { PreferredExtension = IosConstants.BroadcastExtension, ShowsMicrophoneButton = false }; UIAlertController a = UIAlertController.Create("Screen Audio", "Tap the broadcast button, then choose Start Broadcast.", UIAlertControllerStyle.Alert); a.View.AddSubview(picker); picker.Center = new(a.View.Bounds.GetMidX(), 110); a.AddAction(UIAlertAction.Create("Done", UIAlertActionStyle.Cancel, null)); PresentViewController(a, true, null); }
+}
+
+internal sealed class AccountsController : UITableViewController
+{
+    private readonly AppModel model; private IReadOnlyList<AccountEntry> accounts = [];
+    internal AccountsController(AppModel model) { this.model = model; Title = "Accounts"; }
+    public override async void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "account"); NavigationItem.RightBarButtonItem = new(UIBarButtonSystemItem.Add, (_, _) => PromptCreate()); try { accounts = await model.Client!.ListAccountsAsync(); TableView.ReloadData(); } catch (Exception e) { UiHelpers.ShowError(this, e); } }
+    public override nint RowsInSection(UITableView tableView, nint section) => accounts.Count;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath) { UITableViewCell c = tableView.DequeueReusableCell("account", indexPath); var x = c.DefaultContentConfiguration; x.Text = accounts[indexPath.Row].Username; x.SecondaryText = accounts[indexPath.Row].IsAdmin ? "Administrator" : "Account"; c.ContentConfiguration = x; return c; }
+    private void PromptCreate() { UIAlertController p = UIAlertController.Create("Create Account", null, UIAlertControllerStyle.Alert); p.AddTextField(f => f.Placeholder = "Username"); p.AddTextField(f => { f.Placeholder = "Password"; f.SecureTextEntry = true; }); p.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null)); p.AddAction(UIAlertAction.Create("Create", UIAlertActionStyle.Default, async _ => { try { GenericResult result = await model.Client!.CreateAccountAsync(p.TextFields![0].Text ?? "", p.TextFields[1].Text ?? ""); if (!result.Ok) throw new InvalidOperationException(result.Message); accounts = await model.Client.ListAccountsAsync(); TableView.ReloadData(); } catch (Exception e) { UiHelpers.ShowError(this, e); } })); PresentViewController(p, true, null); }
+}

clients/apple/dotnet/VoiceCat.iOS/RootViewController.cs

@@ -0,0 +1,30 @@
+using VoiceCat.Core;
+using UIKit;
+
+namespace VoiceCat.iOS;
+
+internal sealed class RootViewController : UIViewController
+{
+    private readonly AppModel model;
+    private UIViewController? current;
+    internal RootViewController(AppModel model) { this.model = model; model.Changed += Refresh; model.IdentityRequested += ShowIdentity; }
+    public override void ViewDidLoad() { base.ViewDidLoad(); View!.BackgroundColor = UIColor.SystemBackground; Refresh(); }
+
+    private void Refresh()
+    {
+        bool main = model.IsConnected;
+        if (current is MainTabController && main || current is UINavigationController && !main) return;
+        UIViewController next = main ? new MainTabController(model) : new UINavigationController(new ServerListController(model));
+        if (current is not null) { current.WillMoveToParentViewController(null); current.View.RemoveFromSuperview(); current.RemoveFromParentViewController(); }
+        AddChildViewController(next); next.View.Frame = View!.Bounds; next.View.AutoresizingMask = UIViewAutoresizing.All; View.AddSubview(next.View); next.DidMoveToParentViewController(this); current = next;
+    }
+
+    private void ShowIdentity(ServerIdentityChallenge challenge)
+    {
+        UIAlertController alert = UIAlertController.Create(challenge.Status == VoiceCat.Crypto.TofuStatus.Mismatch ? "Server Identity Changed" : "New Server Identity",
+            $"{challenge.Host}:{challenge.Port}\n\nSHA-256\n{challenge.CertificateFingerprint}", UIAlertControllerStyle.Alert);
+        alert.AddAction(UIAlertAction.Create("Reject", UIAlertActionStyle.Destructive, _ => model.ResolveIdentity(false)));
+        alert.AddAction(UIAlertAction.Create("Trust", UIAlertActionStyle.Default, _ => model.ResolveIdentity(true)));
+        PresentViewController(alert, true, null);
+    }
+}

clients/apple/dotnet/VoiceCat.iOS/SceneDelegate.cs

@@ -0,0 +1,22 @@
+using Foundation;
+using UIKit;
+
+namespace VoiceCat.iOS;
+
+[Register("SceneDelegate")]
+internal sealed class SceneDelegate : UIResponder, IUIWindowSceneDelegate
+{
+    [Export("window")]
+    public UIWindow? Window { get; set; }
+
+    [Export("scene:willConnectToSession:options:")]
+    public void WillConnect(UIScene scene, UISceneSession session, UISceneConnectionOptions options)
+    {
+        if (scene is not UIWindowScene windowScene) return;
+        Window = new(windowScene) { RootViewController = new RootViewController(AppModel.Shared) };
+        Window.MakeKeyAndVisible();
+    }
+
+    [Export("sceneDidEnterBackground:")]
+    public void DidEnterBackground(UIScene scene) => AppModel.Shared.Save();
+}

clients/apple/dotnet/VoiceCat.iOS/ServerListController.cs

@@ -0,0 +1,67 @@
+using VoiceCat.Core;
+using UIKit;
+
+namespace VoiceCat.iOS;
+
+internal sealed class ServerListController : UITableViewController
+{
+    private readonly AppModel model;
+    internal ServerListController(AppModel model) { this.model = model; Title = "Servers"; TabBarItem = new(UITabBarSystemItem.Favorites, 0); }
+    public override void ViewDidLoad()
+    {
+        base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "server");
+        NavigationItem.RightBarButtonItem = new(UIBarButtonSystemItem.Add, (_, _) => PresentEditor(null)); model.Changed += Reload;
+    }
+    public override nint RowsInSection(UITableView tableView, nint section) => model.Profiles.Count;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath)
+    {
+        UITableViewCell cell = tableView.DequeueReusableCell("server", indexPath);
+        ServerProfile p = model.Profiles[indexPath.Row];
+        var content = cell.DefaultContentConfiguration; content.Text = p.DisplayName; content.SecondaryText = p.Authentication.ToString(); cell.ContentConfiguration = content;
+        cell.Accessory = UITableViewCellAccessory.DisclosureIndicator; return cell;
+    }
+    public override async void RowSelected(UITableView tableView, NSIndexPath indexPath)
+    {
+        tableView.DeselectRow(indexPath, true); try { await model.ConnectAsync(model.Profiles[indexPath.Row]); } catch (Exception e) { UiHelpers.ShowError(this, e); }
+    }
+    public override UISwipeActionsConfiguration GetTrailingSwipeActionsConfiguration(UITableView tableView, NSIndexPath indexPath)
+    {
+        ServerProfile profile = model.Profiles[indexPath.Row];
+        UIContextualAction edit = UIContextualAction.FromContextualActionStyle(UIContextualActionStyle.Normal, "Edit", (_, _, done) => { PresentEditor(profile); done(true); });
+        UIContextualAction delete = UIContextualAction.FromContextualActionStyle(UIContextualActionStyle.Destructive, "Delete", (_, _, done) => { model.RemoveProfile(profile); done(true); });
+        return UISwipeActionsConfiguration.FromActions([delete, edit]);
+    }
+    private void PresentEditor(ServerProfile? profile) => PresentViewController(new UINavigationController(new ServerEditorController(model, profile)), true, null);
+    private void Reload() { TableView.ReloadData(); NavigationItem.Prompt = model.IsConnecting ? model.Status : null; }
+}
+
+internal sealed class ServerEditorController : UIViewController
+{
+    private readonly AppModel model; private readonly ServerProfile? existing;
+    private readonly UITextField host = UiHelpers.Field("Hostname or IP address");
+    private readonly UITextField port = UiHelpers.Field("Port");
+    private readonly UISegmentedControl mode = new(["Guest", "Account"]);
+    private readonly UITextField name = UiHelpers.Field("Nickname or username");
+    private readonly UITextField password = UiHelpers.Field("Password (optional)", true);
+    internal ServerEditorController(AppModel model, ServerProfile? existing) { this.model = model; this.existing = existing; Title = existing is null ? "Add Server" : "Edit Server"; }
+    public override void ViewDidLoad()
+    {
+        base.ViewDidLoad(); View!.BackgroundColor = UIColor.SystemGroupedBackground; port.KeyboardType = UIKeyboardType.NumberPad;
+        UIStackView stack = new([host, port, mode, name, password]) { Axis = UILayoutConstraintAxis.Vertical, Spacing = 12, TranslatesAutoresizingMaskIntoConstraints = false };
+        View.AddSubview(stack); NSLayoutConstraint.ActivateConstraints([stack.TopAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.TopAnchor, 24), stack.LeadingAnchor.ConstraintEqualTo(View.LayoutMarginsGuide.LeadingAnchor), stack.TrailingAnchor.ConstraintEqualTo(View.LayoutMarginsGuide.TrailingAnchor)]);
+        mode.SelectedSegment = existing?.Authentication == ServerAuthentication.Account ? 1 : 0; host.Text = existing?.Host; port.Text = (existing?.Port ?? 8384).ToString(); name.Text = existing?.Username ?? existing?.Nickname;
+        NavigationItem.LeftBarButtonItem = new(UIBarButtonSystemItem.Cancel, (_, _) => DismissViewController(true, null));
+        NavigationItem.RightBarButtonItem = new(UIBarButtonSystemItem.Save, (_, _) => Save());
+    }
+    private void Save()
+    {
+        try
+        {
+            if (!ushort.TryParse(port.Text, out ushort number)) throw new ArgumentException("Enter a valid port.");
+            ServerAuthentication auth = mode.SelectedSegment == 1 ? ServerAuthentication.Account : ServerAuthentication.Guest;
+            ServerProfile p = ServerProfile.Create(host.Text ?? "", number, auth, auth == ServerAuthentication.Account ? name.Text : null, auth == ServerAuthentication.Guest ? name.Text : null, existing?.Id);
+            model.UpsertProfile(p, password.Text); DismissViewController(true, null);
+        }
+        catch (Exception e) { UiHelpers.ShowError(this, e); }
+    }
+}

clients/apple/dotnet/VoiceCat.iOS/UiHelpers.cs

@@ -0,0 +1,20 @@
+using UIKit;
+
+namespace VoiceCat.iOS;
+
+internal static class UiHelpers
+{
+    internal static void ShowError(UIViewController owner, Exception exception) => ShowMessage(owner, "VoiceCat", exception.Message);
+    internal static void ShowMessage(UIViewController owner, string title, string message)
+    {
+        UIAlertController alert = UIAlertController.Create(title, message, UIAlertControllerStyle.Alert);
+        alert.AddAction(UIAlertAction.Create("OK", UIAlertActionStyle.Default, null)); owner.PresentViewController(alert, true, null);
+    }
+
+    internal static UITextField Field(string placeholder, bool secure = false)
+    {
+        var field = new UITextField { Placeholder = placeholder, BorderStyle = UITextBorderStyle.RoundedRect,
+            SecureTextEntry = secure, TranslatesAutoresizingMaskIntoConstraints = false };
+        field.AccessibilityLabel = placeholder; return field;
+    }
+}

clients/apple/dotnet/VoiceCat.iOS/VoiceCat.iOS.csproj

@@ -0,0 +1,51 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net10.0-ios27.0</TargetFramework>
+    <RuntimeIdentifier Condition="'$(RuntimeIdentifier)' == ''">iossimulator-arm64</RuntimeIdentifier>
+    <SupportedOSPlatformVersion>18.0</SupportedOSPlatformVersion>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <ApplicationTitle>VoiceCat</ApplicationTitle>
+    <ApplicationId>me.iamtalon.voicecat</ApplicationId>
+    <ApplicationVersion>1</ApplicationVersion>
+    <ApplicationDisplayVersion>0.0.1</ApplicationDisplayVersion>
+    <CodesignEntitlements>Entitlements.plist</CodesignEntitlements>
+    <ApplicationManifest>Info.plist</ApplicationManifest>
+    <TrimMode Condition="'$(Configuration)' == 'Release'">full</TrimMode>
+    <NoWarn>$(NoWarn);XCODE_27_0_PREVIEW</NoWarn>
+    <VoiceCatIosStatic>true</VoiceCatIosStatic>
+    <VoiceCatNativeRid Condition="$([System.String]::Copy('$(RuntimeIdentifier)').StartsWith('iossimulator'))">iossimulator-arm64</VoiceCatNativeRid>
+    <VoiceCatNativeRid Condition="'$(VoiceCatNativeRid)' == ''">ios-arm64</VoiceCatNativeRid>
+    <VoiceCatNativeMediaPath>$([System.IO.Path]::GetFullPath('$(MSBuildThisFileDirectory)../../../../dotnet/artifacts/native/runtimes/$(VoiceCatNativeRid)/native/libvoicecat_media.a'))</VoiceCatNativeMediaPath>
+    <VoiceCatBroadcastSdk Condition="$([System.String]::Copy('$(RuntimeIdentifier)').StartsWith('iossimulator'))">iphonesimulator</VoiceCatBroadcastSdk>
+    <VoiceCatBroadcastSdk Condition="'$(VoiceCatBroadcastSdk)' == ''">iphoneos</VoiceCatBroadcastSdk>
+    <VoiceCatBroadcastArch>arm64</VoiceCatBroadcastArch>
+    <VoiceCatBroadcastOutput>$([System.IO.Path]::GetFullPath('$(MSBuildThisFileDirectory)obj/$(Configuration)/$(TargetFramework)/$(RuntimeIdentifier)/broadcast'))</VoiceCatBroadcastOutput>
+    <_ComputePublishLocationDependsOn>VoiceCatPrepareIosNativeAssets;$(_ComputePublishLocationDependsOn)</_ComputePublishLocationDependsOn>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="../../../../dotnet/src/VoiceCat.Core/VoiceCat.Core.csproj" AdditionalProperties="VoiceCatIosStatic=true" />
+    <NativeReference Include="$(VoiceCatNativeMediaPath)" Condition="Exists('$(VoiceCatNativeMediaPath)')">
+      <Kind>Static</Kind>
+      <ForceLoad>true</ForceLoad>
+    </NativeReference>
+    <AdditionalAppExtensions Include="$(VoiceCatBroadcastOutput)">
+      <Name>VoiceCatBroadcast</Name>
+      <BuildOutput>.</BuildOutput>
+      <CodesignEntitlements>$(MSBuildThisFileDirectory)../../iOS/VoiceCatBroadcast/VoiceCatBroadcast.entitlements</CodesignEntitlements>
+    </AdditionalAppExtensions>
+    <BundleResource Include="../../Sources/VoiceCatCore/Sounds/*.wav" Link="Sounds/%(Filename)%(Extension)" />
+    <ImageAsset Include="../../iOS/VoiceCatiOS/Assets.xcassets/**" Link="Assets.xcassets/%(RecursiveDir)%(Filename)%(Extension)" />
+  </ItemGroup>
+  <Target Name="VoiceCatBuildBroadcastExtension" BeforeTargets="_ResolveAppExtensionReferences">
+    <Exec Command="&quot;$(MSBuildThisFileDirectory)build-broadcast-extension.sh&quot; &quot;$(Configuration)&quot; &quot;$(VoiceCatBroadcastSdk)&quot; &quot;$(VoiceCatBroadcastArch)&quot; &quot;$(VoiceCatBroadcastOutput)&quot;" />
+  </Target>
+  <Target Name="VoiceCatPrepareIosNativeAssets">
+    <ItemGroup>
+      <ResolvedFileToPublish Remove="@(ResolvedFileToPublish)" Condition="'%(Filename)%(Extension)' == 'libvoicecat_media.dylib' or '%(Filename)%(Extension)' == 'voicecat_media.dll' or '%(Filename)%(Extension)' == 'libvoicecat_media.so'" />
+      <ResolvedFileToPublish Remove="@(ResolvedFileToPublish)" Condition="'%(Filename)%(Extension)' == 'NOTICE.txt' or '%(Filename)%(Extension)' == 'Opus.txt' or '%(Filename)%(Extension)' == 'RNNoise.txt'" />
+    </ItemGroup>
+  </Target>
+</Project>

clients/apple/dotnet/VoiceCat.iOS/build-broadcast-extension.sh

@@ -0,0 +1,20 @@
+#!/bin/zsh
+set -euo pipefail
+
+configuration="${1:?configuration is required}"
+sdk="${2:?sdk is required}"
+architecture="${3:?architecture is required}"
+output="${4:?output directory is required}"
+script_dir="${0:A:h}"
+project="$script_dir/../../iOS/VoiceCatiOS.xcodeproj"
+
+mkdir -p "$output"
+xcodebuild \
+  -project "$project" \
+  -target VoiceCatBroadcast \
+  -configuration "$configuration" \
+  -sdk "$sdk" \
+  -arch "$architecture" \
+  CONFIGURATION_BUILD_DIR="$output" \
+  CODE_SIGNING_ALLOWED=NO \
+  build