//
//  OptionalObservedObject.swift
//  ComposeUI
//
//  Created by Shadowfacts on 4/15/23.
//

import SwiftUI
import Combine

@propertyWrapper
struct OptionalObservedObject<T: ObservableObject>: DynamicProperty {
    private class Republisher: ObservableObject {
        var cancellable: AnyCancellable?
        var wrapped: T? {
            didSet {
                cancellable?.cancel()
                cancellable = wrapped?.objectWillChange
                    .receive(on: RunLoop.main)
                    .sink { [unowned self] _ in
                        self.objectWillChange.send()
                    }
            }
        }
    }
    
    @StateObject private var republisher = Republisher()
    var wrappedValue: T?
    
    func update() {
        republisher.wrapped = wrappedValue
    }
}