Add ChatClientFactory.

Author: alanedwardes

src/Automation/ChatClientFactory.cs

@@ -0,0 +1,92 @@
+using Microsoft.Extensions.AI;
+using Microsoft.Extensions.Configuration;
+using OllamaSharp;
+using OpenAI;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Estranged.Automation
+{
+	public interface IChatClientFactory
+	{
+		IChatClient CreateClient(string urn);
+		Task<IList<string>> GetModels(string urn, CancellationToken token);
+    }
+
+	internal sealed class ChatClientFactory : IChatClientFactory
+	{
+		private readonly OpenAIClient _openAIClient;
+		private readonly IHttpClientFactory _httpClientFactory;
+		private readonly IConfiguration _configuration;
+
+		public ChatClientFactory(OpenAIClient openAIClient, IHttpClientFactory httpClientFactory, IConfiguration configuration)
+		{
+			_openAIClient = openAIClient;
+			_httpClientFactory = httpClientFactory;
+			_configuration = configuration;
+		}
+
+		public IChatClient CreateClient(string urn)
+		{
+			var parts = urn.Split(':', 3, StringSplitOptions.RemoveEmptyEntries);
+			if (parts.Length != 3 || !parts[0].Equals("urn", StringComparison.OrdinalIgnoreCase))
+			{
+				throw new ArgumentException("Invalid URN format. Expected 'urn:<provider>:<model>'.", nameof(urn));
+			}
+
+			var provider = parts[1].ToLowerInvariant();
+			var model = parts[2];
+
+			switch (provider)
+			{
+				case "openai":
+					return _openAIClient.GetChatClient(model).AsIChatClient();
+				case "ollama":
+					{
+						var httpClient = _httpClientFactory.CreateClient();
+						httpClient.Timeout = TimeSpan.FromHours(1);
+						httpClient.BaseAddress = new Uri(_configuration["OLLAMA_HOST"]);
+						return new OllamaApiClient(httpClient, model);
+					}
+				default:
+					throw new NotSupportedException($"Provider '{provider}' is not supported.");
+			}
+		}
+
+		public async Task<IList<string>> GetModels(string urn, CancellationToken token)
+		{
+            var parts = urn.Split(':', 2, StringSplitOptions.RemoveEmptyEntries);
+            if (parts.Length != 2 || !parts[0].Equals("urn", StringComparison.OrdinalIgnoreCase))
+            {
+                throw new ArgumentException("Invalid URN format. Expected 'urn:<provider>:<model>'.", nameof(urn));
+            }
+
+            var provider = parts[1].ToLowerInvariant();
+
+			switch (provider)
+			{
+				case "openai":
+					var openAiModels = await _openAIClient.GetOpenAIModelClient().GetModelsAsync(token);
+					return [.. openAiModels.Value.Select(x => x.Id)];
+				case "ollama":
+					{
+                        using var httpClient = _httpClientFactory.CreateClient();
+                        httpClient.Timeout = TimeSpan.FromHours(1);
+                        httpClient.BaseAddress = new Uri(_configuration["OLLAMA_HOST"]);
+                        using var client = new OllamaApiClient(httpClient);
+						var ollamaModels = await client.ListLocalModelsAsync(token);
+						return [.. ollamaModels.Select(x => x.Name)];
+                    }
+                default:
+                    throw new NotSupportedException($"Provider '{provider}' is not supported.");
+            }
+        }
+
+	}
+}
+
+

src/Automation/Program.cs

@@ -65,6 +65,7 @@ public static int Main(string[] args)
                     httpClient.BaseAddress = new Uri(configuration["OLLAMA_HOST"]);
                     return new OllamaApiClient(httpClient);
                 })
+                .AddSingleton<IChatClientFactory, ChatClientFactory>()
                 .AddSingleton<IDiscordClient>(discordSocketClient)
                 .AddTransient<IAmazonDynamoDB, AmazonDynamoDBClient>()
                 .AddResponderServices();