TodoStore

TodoStore.swift

import SwiftUI
import Combine


struct State {
    var isCreatingItem: Bool = false
    var partialItemName: String = ""
    var todoItems: [TodoItem] = []
}


final class TodoStore: BindableObject {
    
    private let initialState: State = State()
    private var subsequentStates: [State] = []

    let didChange = PassthroughSubject<Void, Never>()
    
    var stateCount: Int {
        return 1 + subsequentStates.count
    }
    
    var currentStateIndex: Int = 0 {
        didSet {
            didChange.send(())
        }
    }
    
    var state: State {
        get { [[initialState], subsequentStates].flatMap({ $0 })[currentStateIndex] }
        set {
            subsequentStates.append(newValue)
            currentStateIndex = stateCount - 1
        }
    }
    
}