//
//  SelectorGroupHandlerBase.swift
//  VDS
//
//  Created by Matt Bruce on 9/8/22.
//

import Foundation
import UIKit
import Combine

/// Base Class used for any Grouped Form Control of a Selector Type.
open class SelectorGroupHandlerBase<HandlerType: Control>: Control, Changeable {

    //--------------------------------------------------
    // MARK: - Public Properties
    //--------------------------------------------------
    
    /// Array of the HandlerType registered.
    open var selectorViews: [HandlerType] = []
            
    open var onChangeSubscriber: AnyCancellable? {
        willSet {
            if let onChangeSubscriber {
                onChangeSubscriber.cancel()
            }
        }
    }
        
    override open var isEnabled: Bool {
        didSet {
            selectorViews.forEach { $0.isEnabled = isEnabled }
        }
    }
    
    ///The background tint that the component will be placed on. This will automatically adjust other elements as needed and takes “light” or “dark”
    override open var surface: Surface {
        didSet {
            selectorViews.forEach { handler in
                handler.surface = surface
            }
        }
    }
        
    //--------------------------------------------------
    // MARK: - Overrides
    //--------------------------------------------------
    
    /// Handler for the Group to override on a select event.
    /// - Parameter selectedControl: Selected Control the user interacted.
    open func didSelect(_ selectedControl: HandlerType) {
        fatalError("Must override didSelect")
    }

    /// Helper method to execute the valueChanged event.
    open func valueChanged() {
        DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(100)) { [weak self] in
            self?.sendActions(for: .valueChanged)
        }
    }
    
    /// Resets to default settings.
    open override func reset() {
        super.reset()
        selectorViews.forEach{ $0.reset() }
    }
    
    /// Used to update any Accessibility properties.
    open override func updateAccessibility() {        
        super.updateAccessibility()
        setAccessibilityLabel(for: selectorViews)
    }
}

open class SelectorGroupSelectedHandlerBase<HandlerType: Control>: SelectorGroupHandlerBase<HandlerType>{
    
    /// Current Selected Control for this group.
    public var selectedHandler: HandlerType? {
        return selectorViews.filter { $0.isSelected == true }.first
    }
    
    open override func updateAccessibility() {
        super.updateAccessibility()
        if let selectedHandler, let value = selectedHandler.accessibilityValue, let label = selectedHandler.accessibilityLabel {
            accessibilityValue = "\(label) \(value)"
        } else {
            accessibilityValue = nil
        }
    }
}