Add chat functionality (#1)

* Working chatbot

* Clean

* Working LLM chatbot

---------

Co-authored-by: Myx <info@azaaxin.com>

Bot/Handler/ChatCommand/ChatHandler.cs

@@ -0,0 +1,62 @@
+using System.Text;
+using Discord.WebSocket;
+using MediatR;
+using Microsoft.Extensions.Options;
+using OllamaSharp;
+
+namespace Lunaris2.Handler.ChatCommand
+{
+    public record ChatCommand(SocketMessage Message, string FilteredMessage) : IRequest;
+
+    public class ChatHandler : IRequestHandler<ChatCommand>
+    {
+        private readonly OllamaApiClient _ollama;
+        private readonly Dictionary<ulong, Chat?> _chatContexts = new();
+
+        public ChatHandler(IOptions<ChatSettings> chatSettings)
+        {
+            var uri = new Uri(chatSettings.Value.Url);
+            
+            _ollama = new OllamaApiClient(uri)
+            {
+                SelectedModel = chatSettings.Value.Model
+            };
+        }
+        
+        public async Task Handle(ChatCommand command, CancellationToken cancellationToken)
+        {
+            var channelId = command.Message.Channel.Id;
+            _chatContexts.TryAdd(channelId, null);
+
+            var userMessage = command.FilteredMessage;
+            
+            using var setTyping = command.Message.Channel.EnterTypingState();
+            
+            if (string.IsNullOrWhiteSpace(userMessage))
+            {
+                await command.Message.Channel.SendMessageAsync("Am I expected to read your mind?");
+                setTyping.Dispose();
+                return;
+            }
+            
+            var response = await GenerateResponse(userMessage, channelId, cancellationToken);
+            await command.Message.Channel.SendMessageAsync(response);
+            
+            setTyping.Dispose();
+        }
+
+        private async Task<string> GenerateResponse(string userMessage, ulong channelId, CancellationToken cancellationToken)
+        {
+            var response = new StringBuilder();
+
+            if (_chatContexts[channelId] == null)
+            {
+                _chatContexts[channelId] = _ollama.Chat(stream => response.Append(stream.Message?.Content ?? ""));
+            }
+
+            await _chatContexts[channelId].Send(userMessage, cancellationToken);
+
+            return response.ToString();
+        }
+    }
+}

Bot/Handler/ChatCommand/ChatSettings.cs

@@ -0,0 +1,7 @@
+namespace Lunaris2.Handler.ChatCommand;
+
+public class ChatSettings
+{
+    public string Url { get; set; }
+    public string Model { get; set; }
+}