feat: extensions now use idiomatic C# config system

Author: Spelkington

src/extensions/Flowthru.Extensions.Http/Data/Storage/HttpStorageMediumProvider.cs

@@ -1,5 +1,6 @@
 using Flowthru.Core.Data.Storage.Medium;
 using Flowthru.Extensions.Http;
+using Microsoft.Extensions.Options;
 
 namespace Flowthru.Core.Data.Storage;
 
@@ -23,20 +24,21 @@ public sealed class HttpStorageMediumProvider : IStorageMediumProvider
   private readonly HttpCacheOptions? _cache;
 
   /// <summary>
-  /// Creates a new HTTP provider using the supplied client and optional cache options.
+  /// Creates a new HTTP provider using options resolved from DI.
   /// </summary>
-  public HttpStorageMediumProvider(HttpClient httpClient, HttpCacheOptions? cache = null)
+  public HttpStorageMediumProvider(IOptions<HttpOptions> options)
   {
-    _httpClient = httpClient;
-    _cache = cache;
+    var opts = options.Value;
+    _httpClient = opts.CreateClient();
+    _cache = opts.Cache;
   }
 
   /// <summary>
   /// Creates a new HTTP provider with a default <see cref="HttpClient"/> and no caching.
   /// Use this for direct construction outside the DI container.
   /// </summary>
   public HttpStorageMediumProvider()
-    : this(new HttpClient()) { }
+    : this(Microsoft.Extensions.Options.Options.Create(new HttpOptions())) { }
 
   /// <inheritdoc/>
   public bool CanHandle(Uri uri) =>

src/extensions/Flowthru.Extensions.Http/Services/FlowthruServiceBuilderHttpExtensions.cs

@@ -1,12 +1,13 @@
 using Flowthru.Core.Data.Storage;
 using Flowthru.Core.Services;
 using Flowthru.Extensions.Http;
+using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace Flowthru.Extensions.Http.Services;
 
 /// <summary>
-/// Extension methods for registering HTTP storage support with <see cref="FlowthruServiceBuilder"/>.
+/// Extension methods for registering HTTP storage support with <see cref="IFlowthruBuilder"/>.
 /// </summary>
 public static class FlowthruServiceBuilderHttpExtensions
 {
@@ -25,9 +26,13 @@ public static class FlowthruServiceBuilderHttpExtensions
   /// <see cref="Flowthru.Core.Data.Storage.Medium.HttpStorageMedium"/>.
   /// </para>
   /// <para>
+  /// Configuration is bound from the <c>Flowthru:Http</c> section. Properties not
+  /// present in configuration retain their default values.
+  /// </para>
+  /// <para>
   /// <strong>Example:</strong>
   /// <code>
-  /// services.AddFlowthru(flowthru =>
+  /// services.AddFlowthru(configuration, flowthru =>
   /// {
   ///     flowthru.UseHttp();
   ///     flowthru.RegisterCatalog(sp => new MyCatalog(
@@ -42,20 +47,33 @@ public static class FlowthruServiceBuilderHttpExtensions
   /// to <see cref="Flowthru.Core.Data.Storage.Medium.FileStorageMedium"/>.
   /// </para>
   /// </remarks>
-  public static IFlowthruBuilder UseHttp(this IFlowthruBuilder builder) =>
-    builder.UseHttp(_ => { });
+  public static IFlowthruBuilder UseHttp(this IFlowthruBuilder builder)
+  {
+    builder
+      .Services.AddOptions<HttpOptions>()
+      .Configure<IConfiguration>((opts, cfg) => cfg.GetSection("Flowthru:Http").Bind(opts))
+      .ValidateOnStart();
+
+    builder.Services.AddSingleton<IStorageMediumProvider, HttpStorageMediumProvider>();
+
+    return builder;
+  }
 
   /// <summary>
-  /// Enables HTTP(S) remote file access with custom configuration.
+  /// Enables HTTP(S) remote file access with code-first configuration overrides.
   /// </summary>
   /// <param name="builder">The Flowthru service builder.</param>
-  /// <param name="configure">Action to configure HTTP options (timeout, user-agent, etc.).</param>
+  /// <param name="configure">Action to override HTTP options after config-file binding.</param>
   /// <returns>The builder for method chaining.</returns>
   /// <remarks>
   /// <para>
+  /// The <paramref name="configure"/> callback runs after <c>Flowthru:Http</c> section
+  /// binding, so it can selectively override specific values.
+  /// </para>
+  /// <para>
   /// <strong>Example (custom timeout for large remote files):</strong>
   /// <code>
-  /// services.AddFlowthru(flowthru =>
+  /// services.AddFlowthru(configuration, flowthru =>
   /// {
   ///     flowthru.UseHttp(http =>
   ///     {
@@ -71,17 +89,8 @@ public static IFlowthruBuilder UseHttp(
     Action<HttpOptions> configure
   )
   {
-    var options = new HttpOptions();
-    configure(options);
-
-    builder.ConfigureServices(services =>
-    {
-      services.AddSingleton<IStorageMediumProvider>(_ => new HttpStorageMediumProvider(
-        options.CreateClient(),
-        options.Cache
-      ));
-    });
-
+    builder.UseHttp();
+    builder.Services.PostConfigure(configure);
     return builder;
   }
 }

src/extensions/Flowthru.Extensions.Python/Execution/SubprocessPythonExecutor.cs

@@ -6,6 +6,7 @@
 using Flowthru.Extensions.Python.Marshalling;
 using Flowthru.Extensions.Python.Runtime;
 using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
 
 namespace Flowthru.Extensions.Python.Execution;
 
@@ -48,11 +49,11 @@ public sealed class SubprocessPythonExecutor : IPythonExecutor, IDisposable
   /// <param name="logger">The logger instance.</param>
   /// <exception cref="ArgumentNullException"></exception>
   public SubprocessPythonExecutor(
-    PythonRuntimeOptions options,
+    IOptions<PythonRuntimeOptions> options,
     ILogger<SubprocessPythonExecutor> logger
   )
   {
-    _options = options ?? throw new ArgumentNullException(nameof(options));
+    _options = options?.Value ?? throw new ArgumentNullException(nameof(options));
     _logger = logger ?? throw new ArgumentNullException(nameof(logger));
   }
 
@@ -146,7 +147,7 @@ private void EnsureStarted()
 
   private void StartWorker()
   {
-    var pyExe = _options.GetResolvedPythonExe();
+    var pyExe = PythonEnvironmentResolver.ResolvePythonExe(_options);
     var workerScript = Path.Combine(AppContext.BaseDirectory, "flowthru_worker.py");
 
     if (!File.Exists(workerScript))
@@ -180,8 +181,8 @@ private void StartWorker()
 
     // Build init message: sys.path includes configured search paths + the base directory
     // (so flowthru_worker.py can import _flowthru_arrow from the same directory)
-    var sysPaths = _options
-      .GetResolvedModuleSearchPaths()
+    var sysPaths = PythonEnvironmentResolver
+      .ResolveModuleSearchPaths(_options)
       .Concat(new[] { AppContext.BaseDirectory })
       .Distinct()
       .Select(p => (JsonNode?)JsonValue.Create(p))

src/extensions/Flowthru.Extensions.Python/Flowthru.Extensions.Python.csproj

@@ -12,6 +12,13 @@
     <PackageTags>data-engineering;pipeline;python;pythonnet</PackageTags>
   </PropertyGroup>
 
+  <ItemGroup>
+    <!-- Expose internal test helpers to the Python test project -->
+    <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleTo">
+      <_Parameter1>Flowthru.Extensions.Python.Tests</_Parameter1>
+    </AssemblyAttribute>
+  </ItemGroup>
+
   <ItemGroup>
     <!-- Core Flowthru library -->
     <ProjectReference Include="../../core/Flowthru.Core/Flowthru.Core.csproj" />