HandlerManager.swift

import Foundation
import Combine

/// Calls all handlers when triggered, waiting for them to finish running.
actor HandlerManager<Input: Sendable> {
	typealias Handler = @Sendable (Input) async -> Void

	private var handlers: [UUID: Handler] = [:]

	func register(_ handler: @escaping Handler) -> any Cancellable {
		let id = UUID()
		handlers[id] = handler
		
		return AnyCancellable {
			Task {
				self.handlers[id] = nil
			}
		}
	}

	func send(_ input: Input) async {
		for handler in handlers.values {
			await handler(input)
		}
	}
}