engine: Implement structure for game event handling.

Created a module to deal with executing events
on the game object.

backend/uno-game-engine/engine.ts

@@ -1,4 +1,5 @@
 import { getShuffledCardDeck } from './deck';
+import { handleEvent } from './gameEvents';
 
 const NUM_CARDS_PER_PLAYER = 7;
 
@@ -52,4 +53,8 @@ export class GameEngine {
             .find((p: Player) => p.id === player.id)
             .cards.push(this.cardDeck.pop());
     }
+    dispatchEvent(event: GameEvent) {
+        // handle different types of events based on event.type
+        handleEvent(this, event);
+    }
 }

backend/uno-game-engine/gameEvents.ts

@@ -0,0 +1,22 @@
+// this module houses the handlers for various game events.
+
+import { type GameEngine } from './engine';
+
+type GameEventHandler = (game: GameEngine, event: GameEvent) => EventResult;
+
+const map = new Map<GameEventType, GameEventHandler>();
+
+export function registerEventHandler(
+    eventType: GameEventType,
+    handler: GameEventHandler
+) {
+    map.set(eventType, handler);
+}
+
+export function handleEvent(game: GameEngine, event: GameEvent): EventResult {
+    const handler = map.get(event.type);
+    if (!handler) {
+        return { type: 'ERROR', message: 'Invalid event type' };
+    }
+    return handler(game, event);
+}