refactor: Extract interaction handling logic into dedicated ComponentInteractionHandler, AutocompleteHandler, and CommandHandler classes.

src/lib/handlers/CommandHandler.ts

@@ -0,0 +1,39 @@
+import { ChatInputCommandInteraction, MessageFlags } from "discord.js";
+import { AuroraClient } from "@/lib/BotClient";
+import { userService } from "@/modules/user/user.service";
+import { createErrorEmbed } from "@lib/embeds";
+
+/**
+ * Handles slash command execution
+ * Includes user validation and comprehensive error handling
+ */
+export class CommandHandler {
+    static async handle(interaction: ChatInputCommandInteraction): Promise<void> {
+        const command = AuroraClient.commands.get(interaction.commandName);
+
+        if (!command) {
+            console.error(`No command matching ${interaction.commandName} was found.`);
+            return;
+        }
+
+        // Ensure user exists in database
+        try {
+            await userService.getOrCreateUser(interaction.user.id, interaction.user.username);
+        } catch (error) {
+            console.error("Failed to ensure user exists:", error);
+        }
+
+        try {
+            await command.execute(interaction);
+        } catch (error) {
+            console.error(error);
+            const errorEmbed = createErrorEmbed('There was an error while executing this command!');
+
+            if (interaction.replied || interaction.deferred) {
+                await interaction.followUp({ embeds: [errorEmbed], flags: MessageFlags.Ephemeral });
+            } else {
+                await interaction.reply({ embeds: [errorEmbed], flags: MessageFlags.Ephemeral });
+            }
+        }
+    }
+}