//
//  AsyncToggle.swift
//  TuskerComponents
//
//  Created by Shadowfacts on 4/7/24.
//  Copyright © 2024 Shadowfacts. All rights reserved.
//

import SwiftUI

public struct AsyncToggle: View {
    let titleKey: LocalizedStringKey
    #if !os(visionOS)
    @available(iOS, obsoleted: 16.0, message: "Switch to LabeledContent")
    let labelHidden: Bool
    #endif
    @Binding var mode: Mode
    let onChange: (Bool) async -> Bool
    
    public init(_ titleKey: LocalizedStringKey, labelHidden: Bool = false, mode: Binding<Mode>, onChange: @escaping (Bool) async -> Bool) {
        self.titleKey = titleKey
        #if !os(visionOS)
        self.labelHidden = labelHidden
        #endif
        self._mode = mode
        self.onChange = onChange
    }
    
    public var body: some View {
        #if os(visionOS)
        LabeledContent(titleKey) {
            toggleOrSpinner
        }
        #else
        if #available(iOS 16.0, *) {
            LabeledContent(titleKey) {
                toggleOrSpinner
            }
        } else if labelHidden {
            toggleOrSpinner
        } else {
            HStack {
                Text(titleKey)
                Spacer()
                toggleOrSpinner
            }
        }
        #endif
    }
    
    @ViewBuilder
    private var toggleOrSpinner: some View {
        ZStack {
            Toggle(titleKey, isOn: Binding {
                mode == .on
            } set: { newValue in
                mode = .loading
                Task {
                    let operationCompleted = await onChange(newValue)
                    if operationCompleted {
                        mode = newValue ? .on : .off
                    } else {
                        mode = newValue ? .off : .on
                    }
                }
            })
            .labelsHidden()
            .opacity(mode == .loading ? 0 : 1)
            
            if mode == .loading {
                ProgressView()
            }
        }
    }
    
    public enum Mode {
        case off
        case loading
        case on
    }
}

#Preview {
    @State var mode = AsyncToggle.Mode.on
    return AsyncToggle("", mode: $mode) { _ in
        try! await Task.sleep(nanoseconds: NSEC_PER_SEC)
        return true
    }
}