Prototype lightweight event bus for iOS swift 3.3

EventBus.swift

//
//  EventBus.swift
//  R2S
//
//  Created by Vito Cuaderno on 6/1/18.
//  Copyright © 2018 Total Integrated Resources. All rights reserved.
//
import Foundation

final class EventBus {
    static let sharedInstance = EventBus()
    typealias handlerClosure = (_ value:AnyObject) -> Void
    /**
        Singleton
    */
    private init() {}
    
    /**
        Abstract class
        extend to create custom events
     sample:
     let subscription = EventBus.sharedInstance.subscribe(to: "sample event") { value in
     let value = value as! BaseViewController
     printD(value)
     }
     
     let event = EventBus.Event("sample event")
     EventBus.sharedInstance.register(event: event)
     
     event.emit(self)
     _ = subscription.unsubscribe()
     event.emit(self)
     EventBus.sharedInstance.unregister(event: event)
     event.emit(self)
     
    */
    fileprivate var events = [Event]()
    fileprivate var subscribers = [Subscriber]()
    
    class Subscriber {
        init(for eventName:String, handler:@escaping handlerClosure) {
            self.eventName = eventName
            self.handler = handler
        }
        fileprivate let id = EventBus.sharedInstance.generateId()
        fileprivate var eventName = ""
        fileprivate var handler:handlerClosure?
        
        final func unsubscribe() -> Bool {
            EventBus.sharedInstance.subscribers = EventBus.sharedInstance.subscribers.filter{ $0.id != self.id}
            return true
        }
    }
    
    class Event {
        fileprivate let id = EventBus.sharedInstance.generateId()
        var name = ""
        
        init(_ name:String) {
            self.name = name
        }
        /**
            execute all event handlers of subscribers from registered events
        */
        final func emit(_ value:AnyObject) {
            if (EventBus.sharedInstance.events.filter{ $0.id == self.id }.count > 0) {
                EventBus.sharedInstance.subscribers.forEach{
                    if $0.eventName == self.name {
                        $0.handler?(value)
                    }
                }
            } else {
                printE("Event: \(name) is not registered.")
            }
            
        }
    }
    
    final func generateId() -> Int {
        return Int(Date().timeIntervalSince1970)
    }
    
    func register(event:Event) {
        if (events.filter{ $0.id == event.id }.count <= 0) {
            events.append(event)
        }
    }
    
    func unregister(event:Event) {
        events = events.filter{ $0.id != event.id }
    }
    
    final func subscribe(to eventName:String, handler: @escaping handlerClosure ) -> Subscriber {
        let subscriber = Subscriber(for: eventName, handler: handler)
        self.subscribers.append(subscriber)
        return subscriber
    }
}