Tusker/Packages/TuskerComponents/Sources/TuskerComponents/AsyncPicker.swift

//
//  AsyncPicker.swift
//  TuskerComponents
//
//  Created by Shadowfacts on 4/9/24.
//

import SwiftUI

public struct AsyncPicker<V: Hashable, Content: View>: View {
    let titleKey: LocalizedStringKey
    #if !os(visionOS)
    @available(iOS, obsoleted: 16.0, message: "Switch to LabeledContent")
    let labelHidden: Bool
    #endif
    let alignment: Alignment
    @Binding var value: V
    let onChange: (V) async -> Bool
    let content: Content
    @State private var isLoading = false
    
    public init(_ titleKey: LocalizedStringKey, labelHidden: Bool = false, alignment: Alignment = .center, value: Binding<V>, onChange: @escaping (V) async -> Bool, @ViewBuilder content: () -> Content) {
        self.titleKey = titleKey
        #if !os(visionOS)
        self.labelHidden = labelHidden
        #endif
        self.alignment = alignment
        self._value = value
        self.onChange = onChange
        self.content = content()
    }
    
    public var body: some View {
        #if os(visionOS)
        LabeledContent(titleKey) {
            picker
        }
        #else
        if #available(iOS 16.0, *) {
            LabeledContent(titleKey) {
                picker
            }
        } else if labelHidden {
            picker
        } else {
            HStack {
                Text(titleKey)
                Spacer()
                picker
            }
        }
        #endif
    }
    
    private var picker: some View {
        ZStack(alignment: alignment) {
            Picker(titleKey, selection: Binding(get: {
                value
            }, set: { newValue in
                let oldValue = value
                value = newValue
                isLoading = true
                Task {
                    let operationCompleted = await onChange(newValue)
                    if !operationCompleted {
                        value = oldValue
                    }
                    isLoading = false
                }
            })) {
                content
            }
            .labelsHidden()
            .opacity(isLoading ? 0 : 1)

            if isLoading {
                ProgressView()
            }
        }
    }
}

#Preview {
    @State var value = 0
    return AsyncPicker("", value: $value) { _ in
        try! await Task.sleep(nanoseconds: NSEC_PER_SEC)
        return true
    } content: {
        ForEach(0..<10) {
            Text("\($0)").tag($0)
        }
    }
}