1class EventManager {
2    constructor() {
3        this.subscribers = new WeakMap();
4        this.eventHistory = [];
5    }
6
7    subscribe(subscriber, eventType, callback) {
8        if (!this.subscribers.has(subscriber)) {
9            this.subscribers.set(subscriber, new Map());
10        }
11
12        const subscriberEvents = this.subscribers.get(subscriber);
13        if (!subscriberEvents.has(eventType)) {
14            subscriberEvents.set(eventType, new Set());
15        }
16
17        subscriberEvents.get(eventType).add(callback);
18
19        // Keep track of subscription history
20        this.eventHistory.push({
21            subscriber,
22            eventType,
23            timestamp: new Date()
24        });
25    }
26
27    emit(eventType, data) {
28        for (let [subscriber, events] of this.subscribers) {
29            const callbacks = events.get(eventType);
30            if (callbacks) {
31                callbacks.forEach(callback => callback(data));
32            }
33        }
34    }
35
36    unsubscribe(subscriber, eventType) {
37        const subscriberEvents = this.subscribers.get(subscriber);
38        if (subscriberEvents) {
39            subscriberEvents.delete(eventType);
40        }
41    }
42}