feat: register services only if feature flags are enabled

Server/Modules/Items/Services/ItemGenerator.cs

@@ -13,20 +13,18 @@ public class ItemGenerator : IItemGenerator
         private readonly List<RarityModifier> _modifiers;
         private readonly INameGenerator _nameGenerator;
         private readonly PrefixesGenerator _prefixes;
-        private readonly IAIInstructionProvider _ai;
+        private readonly IAIInstructionProvider? _ai;
         private readonly IFeatureManager _featureManager;
 
         public ItemGenerator(
             INameGenerator nameGenerator,
             PrefixesGenerator prefixes,
-            IAIInstructionProvider ai,
-            IFeatureManager featureManager
+            IAIInstructionProvider? ai = null
         )
         {
             _nameGenerator = nameGenerator;
             _prefixes = prefixes;
             _ai = ai;
-            _featureManager = featureManager;
 
             _rnd = new Random();
 
@@ -104,7 +102,7 @@ public async Task<Item> Generate()
 
             await _prefixes.AddPrefixes(item);
 
-            if (await _featureManager.IsEnabledAsync(FeatureFlags.USE_AI))
+            if (_ai is not null)
             {
                 item.History = await GenerateDescription(item);
             }

Server/Modules/Shared/BuilderExtensions.cs

@@ -0,0 +1,29 @@
+using Fracture.Server.Modules.AI.Services;
+using Fracture.Server.Modules.Shared.Configuration;
+using Microsoft.FeatureManagement;
+
+namespace Fracture.Server.Modules.Shared
+{
+    public static class BuilderExtensions
+    {
+        /// <summary>
+        /// Adds to services elements only if there is a proper feature flag enabled in the configuration
+        /// </summary>
+        public static async Task AddFeatureGatedServices(this IServiceCollection services)
+        {
+            IConfiguration configuration = new ConfigurationBuilder()
+                .AddJsonFile("appsettings.json")
+                .Build();
+            var featureDefinitionProvider = new ConfigurationFeatureDefinitionProvider(
+                configuration.GetSection(FeatureFlags.CONFIG_SECTION)
+            );
+            var featureManager = new FeatureManager(featureDefinitionProvider);
+
+            if (await featureManager.IsEnabledAsync(FeatureFlags.USE_AI))
+                services.AddSingleton<
+                    IAIInstructionProvider,
+                    OpenAICompatibleInstructionProvider
+                >();
+        }
+    }
+}

Server/Program.cs

@@ -8,6 +8,7 @@
 using Fracture.Server.Modules.Shared.Configuration;
 using Fracture.Server.Modules.Shared.NameGenerators;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Hosting;
 using Microsoft.FeatureManagement;
 
@@ -21,7 +22,6 @@
 builder.Services.AddSingleton<IItemGenerator, ItemGenerator>();
 builder.Services.AddSingleton<PrefixesGenerator>();
 builder.Services.AddSingleton<VersionInfoProvider>();
-builder.Services.AddSingleton<IAIInstructionProvider, OpenAICompatibleInstructionProvider>();
 
 builder.Services.AddScoped<IUsersRepository, UsersRepository>();
 builder.Services.AddScoped<IItemsRepository, ItemsRepository>();
@@ -30,6 +30,8 @@
     builder.Configuration.GetSection(FeatureFlags.CONFIG_SECTION)
 );
 
+await builder.Services.AddFeatureGatedServices();
+
 builder.Services
     .AddRazorComponents()
     .AddInteractiveServerComponents()