OPC # 0001: Extract OPC into standalone repo

ControlPlane.Core/Services/TenantRegistryService.cs

@@ -0,0 +1,77 @@
+using System.Xml.Serialization;
+using ControlPlane.Core.Models;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Logging;
+
+namespace ControlPlane.Core.Services;
+
+/// <summary>
+/// Reads and writes per-tenant XML config files under the ClientAssets folder.
+/// One file per tenant: {subdomain}.xml
+/// Thread-safe for concurrent reads; writes are serialized per subdomain via per-file locking.
+/// </summary>
+public class TenantRegistryService
+{
+    private readonly string _folder;
+    private readonly ILogger<TenantRegistryService> _logger;
+    private static readonly XmlSerializer Serializer = new(typeof(TenantRecord));
+
+    // One lock object per subdomain so writes to different tenants never block each other
+    private readonly System.Collections.Concurrent.ConcurrentDictionary<string, object> _locks = new(StringComparer.OrdinalIgnoreCase);
+
+    public TenantRegistryService(IConfiguration configuration, ILogger<TenantRegistryService> logger)
+    {
+        _folder = configuration["ClientAssets__Folder"] ?? configuration["ClientAssets:Folder"]
+                  ?? Path.GetFullPath(Path.Combine(AppContext.BaseDirectory, "..", "ClientAssets"));
+        _logger = logger;
+        Directory.CreateDirectory(_folder);
+    }
+
+    // -- Write --
+
+    public void Save(TenantRecord record)
+    {
+        var path = FilePath(record.Subdomain);
+        var gate = _locks.GetOrAdd(record.Subdomain, _ => new object());
+        lock (gate)
+        {
+            using var writer = new StreamWriter(path, append: false, System.Text.Encoding.UTF8);
+            Serializer.Serialize(writer, record);
+        }
+        _logger.LogInformation("Saved tenant record: {Path}", path);
+    }
+
+    // -- Read --
+
+    public TenantRecord? TryGet(string subdomain)
+    {
+        var path = FilePath(subdomain);
+        if (!File.Exists(path)) return null;
+        using var reader = new StreamReader(path, System.Text.Encoding.UTF8);
+        return (TenantRecord?)Serializer.Deserialize(reader);
+    }
+
+    public IReadOnlyList<TenantRecord> GetAll()
+    {
+        var results = new List<TenantRecord>();
+        foreach (var file in Directory.EnumerateFiles(_folder, "*.xml"))
+        {
+            try
+            {
+                using var reader = new StreamReader(file, System.Text.Encoding.UTF8);
+                if (Serializer.Deserialize(reader) is TenantRecord record)
+                    results.Add(record);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogWarning(ex, "Skipping malformed tenant file: {File}", file);
+            }
+        }
+        return results;
+    }
+
+    public bool Exists(string subdomain) => File.Exists(FilePath(subdomain));
+
+    private string FilePath(string subdomain) =>
+        Path.Combine(_folder, $"{subdomain.ToLowerInvariant()}.xml");
+}