Added missing files

ChatAAC/Services/AiService.cs

@@ -0,0 +1,54 @@
+using System;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+using System.Text;
+using System.Threading.Tasks;
+using ChatAAC.Models;
+
+namespace ChatAAC.Services;
+
+public class AiService
+{
+    private readonly OllamaClient _ollamaClient = new();
+    private readonly ITtsService _ttsService = InitializeTtsService();
+
+
+    private static ITtsService InitializeTtsService()
+    {
+        if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+            return new MacTtsService();
+        if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            return new WindowsTtsService();
+        if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+            return new LinuxTtsService();
+
+        throw new PlatformNotSupportedException("The platform is not supported for TTS.");
+    }
+
+    public async Task<string> GetAiResponseAsync(string prompt, string form, string tense)
+    {
+        var chatRequest = new ChatRequest
+        {
+            Prompt = prompt,
+            Form = form,
+            Tense = tense
+        };
+
+        var response = await _ollamaClient.ChatAsync(chatRequest);
+        return await CombineResponseAsync(response);
+    }
+
+    public async Task SpeakResponseAsync(string response)
+    {
+        await _ttsService.SpeakAsync(response);
+    }
+
+    private static async Task<string> CombineResponseAsync(IAsyncEnumerable<string> responseStream)
+    {
+        var builder = new StringBuilder();
+        await foreach (var chunk in responseStream)
+            builder.Append(chunk);
+
+        return builder.ToString();
+    }
+}