feat(lmxproxy): phase 1 — v2 protocol types and domain model

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lmxproxy/src-reference/ZB.MOM.WW.LmxProxy.Client/LmxProxyClient.CodeFirstSubscription.cs

@@ -0,0 +1,156 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using ZB.MOM.WW.LmxProxy.Client.Domain;
+
+namespace ZB.MOM.WW.LmxProxy.Client
+{
+    public partial class LmxProxyClient
+    {
+        private class CodeFirstSubscription : ISubscription
+        {
+            private readonly IScadaService _client;
+            private readonly string _sessionId;
+            private readonly List<string> _tags;
+            private readonly Action<string, Vtq> _onUpdate;
+            private readonly ILogger<LmxProxyClient> _logger;
+            private readonly Action<ISubscription>? _onDispose;
+            private readonly CancellationTokenSource _cts = new();
+            private Task? _processingTask;
+            private bool _disposed;
+
+            /// <summary>
+            /// Initializes a new instance of the CodeFirstSubscription class.
+            /// </summary>
+            /// <param name="client">The gRPC ScadaService client.</param>
+            /// <param name="sessionId">The session identifier.</param>
+            /// <param name="tags">The list of tag addresses to subscribe to.</param>
+            /// <param name="onUpdate">Callback invoked when tag values change.</param>
+            /// <param name="logger">Logger for diagnostic information.</param>
+            /// <param name="onDispose">Optional callback invoked when the subscription is disposed.</param>
+            public CodeFirstSubscription(
+                IScadaService client,
+                string sessionId,
+                List<string> tags,
+                Action<string, Vtq> onUpdate,
+                ILogger<LmxProxyClient> logger,
+                Action<ISubscription>? onDispose = null)
+            {
+                _client = client;
+                _sessionId = sessionId;
+                _tags = tags;
+                _onUpdate = onUpdate;
+                _logger = logger;
+                _onDispose = onDispose;
+            }
+
+            /// <summary>
+            /// Starts the subscription asynchronously and begins processing tag value updates.
+            /// </summary>
+            /// <param name="cancellationToken">Cancellation token.</param>
+            /// <returns>A task that completes when the subscription processing has started.</returns>
+            public Task StartAsync(CancellationToken cancellationToken = default)
+            {
+                _processingTask = ProcessUpdatesAsync(cancellationToken);
+                return Task.CompletedTask;
+            }
+
+            private async Task ProcessUpdatesAsync(CancellationToken cancellationToken)
+            {
+                try
+                {
+                    var request = new SubscribeRequest
+                    {
+                        SessionId = _sessionId,
+                        Tags = _tags,
+                        SamplingMs = 1000
+                    };
+
+                    using var linkedCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, _cts.Token);
+
+                    await foreach (VtqMessage vtq in _client.SubscribeAsync(request, linkedCts.Token))
+                    {
+                        try
+                        {
+                            Vtq convertedVtq = ConvertToVtq(vtq.Tag, vtq);
+                            _onUpdate(vtq.Tag, convertedVtq);
+                        }
+                        catch (Exception ex)
+                        {
+                            _logger.LogError(ex, "Error processing subscription update for {Tag}", vtq.Tag);
+                        }
+                    }
+                }
+                catch (OperationCanceledException) when (_cts.Token.IsCancellationRequested || cancellationToken.IsCancellationRequested)
+                {
+                    _logger.LogDebug("Subscription cancelled");
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogError(ex, "Error in subscription processing");
+                    try { await _cts.CancelAsync(); } catch { /* ignore */ }
+                }
+                finally
+                {
+                    if (!_disposed)
+                    {
+                        _disposed = true;
+                        _onDispose?.Invoke(this);
+                    }
+                }
+            }
+
+            /// <summary>
+            /// Asynchronously disposes the subscription and stops processing tag updates.
+            /// </summary>
+            /// <returns>A task representing the asynchronous disposal operation.</returns>
+            public async Task DisposeAsync()
+            {
+                if (_disposed) return;
+                _disposed = true;
+
+                await _cts.CancelAsync();
+
+                try
+                {
+                    if (_processingTask != null)
+                    {
+                        await _processingTask;
+                    }
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogError(ex, "Error disposing subscription");
+                }
+                finally
+                {
+                    _cts.Dispose();
+                    _onDispose?.Invoke(this);
+                }
+            }
+
+            /// <summary>
+            /// Synchronously disposes the subscription and stops processing tag updates.
+            /// </summary>
+            public void Dispose()
+            {
+                if (_disposed) return;
+
+                try
+                {
+                    Task task = DisposeAsync();
+                    if (!task.Wait(TimeSpan.FromSeconds(5)))
+                    {
+                        _logger.LogWarning("Subscription disposal timed out");
+                    }
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogError(ex, "Error during synchronous disposal");
+                }
+            }
+        }
+    }
+}