Add ActiveDevice + DeviceRegistry + HubEnvelopes + IDeviceClient/Channel implementations

backend/DeviceHub/ActiveDevice.cs

@@ -0,0 +1,112 @@
+using System.Collections.Concurrent;
+using System.Net.WebSockets;
+using System.Text;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+using backend.Realtime;
+using backend.Tools;
+
+namespace backend.DeviceHub;
+
+public interface IDeviceClient
+{
+    Task SendEnvelopeAsync<T>(T envelope, CancellationToken ct) where T : HubEnvelope;
+    Task SendBinaryAsync(ReadOnlyMemory<byte> bytes, CancellationToken ct);
+}
+
+public class ActiveDevice : IDeviceChannel, IDeviceClient, ISessionOutput, IAsyncDisposable
+{
+    public Guid DeviceId { get; }
+    public WebSocket Ws => _ws;
+    public RealtimeSession? CurrentSession { get; set; }
+    public CancellationTokenSource? SessionCts { get; set; }
+
+    private readonly WebSocket _ws;
+    private readonly SemaphoreSlim _sendLock = new(1, 1);
+    private readonly ConcurrentDictionary<string, TaskCompletionSource<JsonElement>> _pendingTools = new();
+
+    public ActiveDevice(Guid deviceId, WebSocket ws)
+    {
+        DeviceId = deviceId;
+        _ws = ws;
+    }
+
+    public async Task SendEnvelopeAsync<T>(T envelope, CancellationToken ct) where T : HubEnvelope
+    {
+        var json = JsonSerializer.Serialize(envelope, envelope.GetType());
+        await _sendLock.WaitAsync(ct);
+        try
+        {
+            await _ws.SendAsync(Encoding.UTF8.GetBytes(json),
+                WebSocketMessageType.Text, endOfMessage: true, ct);
+        }
+        finally { _sendLock.Release(); }
+    }
+
+    public async Task SendBinaryAsync(ReadOnlyMemory<byte> bytes, CancellationToken ct)
+    {
+        await _sendLock.WaitAsync(ct);
+        try
+        {
+            await _ws.SendAsync(bytes, WebSocketMessageType.Binary, endOfMessage: true, ct);
+        }
+        finally { _sendLock.Release(); }
+    }
+
+    public Task WriteEnvelopeAsync(JsonObject envelope, CancellationToken ct)
+    {
+        var json = envelope.ToJsonString();
+        return WriteRawTextAsync(json, ct);
+    }
+
+    private async Task WriteRawTextAsync(string json, CancellationToken ct)
+    {
+        await _sendLock.WaitAsync(ct);
+        try
+        {
+            await _ws.SendAsync(Encoding.UTF8.GetBytes(json),
+                WebSocketMessageType.Text, endOfMessage: true, ct);
+        }
+        finally { _sendLock.Release(); }
+    }
+
+    public Task WriteBinaryAsync(ReadOnlyMemory<byte> bytes, CancellationToken ct)
+        => SendBinaryAsync(bytes, ct);
+
+    public Task<JsonElement> CallPiToolAsync(string name, JsonElement args, CancellationToken ct)
+    {
+        var callId = "srv_" + Guid.NewGuid().ToString("N")[..12];
+        var tcs = new TaskCompletionSource<JsonElement>(TaskCreationOptions.RunContinuationsAsynchronously);
+        _pendingTools[callId] = tcs;
+
+        var envelope = new ToolCallEnvelope("tool_call", callId, name, args);
+        _ = SendEnvelopeAsync(envelope, ct);
+
+        ct.Register(() => tcs.TrySetCanceled());
+        return tcs.Task;
+    }
+
+    public void CompleteToolResult(ToolResultEnvelope env)
+    {
+        if (!_pendingTools.TryRemove(env.CallId, out var tcs)) return;
+        if (env.Ok && env.Result is JsonElement r) tcs.TrySetResult(r);
+        else
+        {
+            var msg = (env.Error ?? "unknown").Replace("\\", "\\\\").Replace("\"", "\\\"");
+            var doc = JsonDocument.Parse($$"""{"ok":false,"error":"{{msg}}"}""");
+            tcs.TrySetResult(doc.RootElement.Clone());
+        }
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        try
+        {
+            if (_ws.State == WebSocketState.Open)
+                await _ws.CloseAsync(WebSocketCloseStatus.NormalClosure, "bye", CancellationToken.None);
+        }
+        catch { }
+        _ws.Dispose();
+        _sendLock.Dispose();
+    }
+}