Using IHostingService for TTS listening and playing in background.

TTSEngine.cs

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+using System.Runtime.InteropServices;
+using System.Web;
+using Microsoft.Extensions.Hosting;
+using NAudio.Wave;
+using NAudio.Wave.SampleProviders;
+using Serilog;
+using TwitchChatTTS.Chat.Speech;
+
+namespace TwitchChatTTS
+{
+    public class TTSEngine : IHostedService
+    {
+        private readonly AudioPlaybackEngine _playback;
+        private readonly TTSPlayer _player;
+        private readonly ILogger _logger;
+
+
+        public TTSEngine(AudioPlaybackEngine playback, TTSPlayer player, ILogger logger)
+        {
+            _playback = playback;
+            _player = player;
+            _logger = logger;
+        }
+
+
+        public Task StartAsync(CancellationToken cancellationToken)
+        {
+            Task.Run(async () =>
+            {
+                while (true)
+                {
+                    try
+                    {
+                        if (cancellationToken.IsCancellationRequested)
+                        {
+                            _logger.Warning("TTS Engine - Cancellation requested.");
+                            return;
+                        }
+                        while (_player.IsEmpty() || _player.Playing != null)
+                        {
+                            await Task.Delay(200, cancellationToken);
+                            continue;
+                        }
+
+                        var messageData = _player.ReceiveReady();
+                        if (messageData == null)
+                            continue;
+
+                        if (messageData.Audio != null)
+                        {
+                            _player.Playing = messageData;
+                            _playback.AddMixerInput(messageData.Audio);
+                            string message = string.Join(" ", messageData.Messages.Select(m => m.File == null ? m.Message : '(' + m.File + ')'));
+                            _logger.Debug($"Playing TTS message [message: {message}][chatter id: {messageData.ChatterId}][priority: {messageData.Priority}][message id: {messageData.MessageId}][broadcaster id: {messageData.RoomId}]");
+                        }
+                    }
+                    catch (Exception e)
+                    {
+                        _logger.Error(e, "Failed to play a TTS audio message");
+                    }
+                }
+            });
+            return Task.CompletedTask;
+        }
+
+        public Task StopAsync(CancellationToken cancellationToken)
+        {
+            return Task.CompletedTask;
+        }
+    }
+}