Add DI helpers for scenarios not requiring AI

service/Core/AI/DependencyInjection.cs

@@ -0,0 +1,51 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.KernelMemory.AI;
+
+// ReSharper disable once CheckNamespace
+namespace Microsoft.KernelMemory;
+
+public static partial class KernelMemoryBuilderExtensions
+{
+    /// <summary>
+    /// Inject a fake embedding generator that will throw an exception if used
+    /// </summary>
+    /// <param name="builder">KM builder</param>
+    public static IKernelMemoryBuilder WithoutEmbeddingGenerator(this IKernelMemoryBuilder builder)
+    {
+        builder.Services.AddNoEmbeddingGenerator();
+        return builder;
+    }
+
+    /// <summary>
+    /// Inject a fake embedding generator that will throw an exception if used
+    /// </summary>
+    /// <param name="builder">KM builder</param>
+    public static IKernelMemoryBuilder WithoutTextGenerator(this IKernelMemoryBuilder builder)
+    {
+        builder.Services.AddNoTextGenerator();
+        return builder;
+    }
+}
+
+public static partial class DependencyInjection
+{
+    /// <summary>
+    /// Inject a fake embedding generator that will throw an exception if used
+    /// </summary>
+    /// <param name="services">.NET services</param>
+    public static IServiceCollection AddNoEmbeddingGenerator(this IServiceCollection services)
+    {
+        return services.AddSingleton<ITextEmbeddingGenerator, NoEmbeddingGenerator>();
+    }
+
+    /// <summary>
+    /// Inject a fake text generator that will throw an exception if used
+    /// </summary>
+    /// <param name="services">.NET services</param>
+    public static IServiceCollection AddNoTextGenerator(this IServiceCollection services)
+    {
+        return services.AddSingleton<ITextGenerator, NoTextGenerator>();
+    }
+}

service/Core/AI/NoEmbeddingGenerator.cs

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+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+
+namespace Microsoft.KernelMemory.AI;
+
+/// <summary>
+/// Disabled embedding generator used when using KM without embeddings,
+/// e.g. when using the internal orchestration to run jobs that don't require AI.
+/// </summary>
+public class NoEmbeddingGenerator : ITextEmbeddingGenerator
+{
+    private readonly ILogger<ITextEmbeddingGenerator> _log;
+
+    public NoEmbeddingGenerator(ILoggerFactory loggerFactory)
+    {
+        this._log = loggerFactory.CreateLogger<ITextEmbeddingGenerator>();
+    }
+
+    /// <inheritdoc />
+    public int MaxTokens => int.MaxValue;
+
+    /// <inheritdoc />
+    public int CountTokens(string text)
+    {
+        throw this.Error();
+    }
+
+    /// <inheritdoc />
+    public Task<Embedding> GenerateEmbeddingAsync(string text, CancellationToken cancellationToken = default)
+    {
+        throw this.Error();
+    }
+
+    private NotImplementedException Error()
+    {
+        this._log.LogCritical("The application is attempting to generate embeddings even if embedding generation has been disabled");
+        return new NotImplementedException("Embedding generation has been disabled");
+    }
+}

service/Core/AI/NoTextGenerator.cs

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+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using Microsoft.Extensions.Logging;
+
+namespace Microsoft.KernelMemory.AI;
+
+/// <summary>
+/// Disabled text generator used when using KM without AI queries and summaries,
+/// e.g. when using the internal orchestration to run jobs that don't require AI.
+/// </summary>
+public class NoTextGenerator : ITextGenerator
+{
+    private readonly ILogger<ITextGenerator> _log;
+
+    public NoTextGenerator(ILoggerFactory loggerFactory)
+    {
+        this._log = loggerFactory.CreateLogger<ITextGenerator>();
+    }
+
+    /// <inheritdoc />
+    public int MaxTokenTotal => int.MaxValue;
+
+    /// <inheritdoc />
+    public int CountTokens(string text)
+    {
+        throw this.Error();
+    }
+
+    /// <inheritdoc />
+    public IAsyncEnumerable<string> GenerateTextAsync(string prompt, TextGenerationOptions options, CancellationToken cancellationToken = default)
+    {
+        throw this.Error();
+    }
+
+    private NotImplementedException Error()
+    {
+        this._log.LogCritical("The application is attempting to generate text even if text generation has been disabled");
+        return new NotImplementedException("Text generation has been disabled");
+    }
+}