//
//  UIAlertControllerExtensions.swift
//  CapFinder
//
//  Created by User on 23.03.18.
//  Copyright © 2018 User. All rights reserved.
//

import Foundation
import UIKit

extension UIAlertController {

    private struct AssociatedKeys {
        static var blurStyleKey = "UIAlertController.blurStyleKey"
    }

    public var blurStyle: UIBlurEffect.Style {
        get {
            return objc_getAssociatedObject(self, &AssociatedKeys.blurStyleKey) as? UIBlurEffect.Style ?? .extraLight
        } set (style) {
            objc_setAssociatedObject(self, &AssociatedKeys.blurStyleKey, style, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)

            view.setNeedsLayout()
            view.layoutIfNeeded()
        }
    }

    public var cancelButtonColor: UIColor? {
        return blurStyle == .dark ? UIColor(red: 28.0/255.0, green: 28.0/255.0, blue: 28.0/255.0, alpha: 1.0) : nil
    }

    private var visualEffectView: UIVisualEffectView? {
        if let presentationController = presentationController, presentationController.responds(to: Selector(("popoverView"))), let view = presentationController.value(forKey: "popoverView") as? UIView // We're on an iPad and visual effect view is in a different place.
        {
            return view.recursiveSubviews.compactMap({$0 as? UIVisualEffectView}).first
        }

        return view.recursiveSubviews.compactMap({$0 as? UIVisualEffectView}).first
    }

    private var cancelActionView: UIView? {
        return view.recursiveSubviews.compactMap({
            $0 as? UILabel}
            ).first(where: {
                $0.text == actions.first(where: { $0.style == .cancel })?.title
            })?.superview?.superview
    }

    public convenience init(title: String?, message: String?, preferredStyle: UIAlertController.Style, blurStyle: UIBlurEffect.Style) {
        self.init(title: title, message: message, preferredStyle: preferredStyle)
        self.blurStyle = blurStyle
    }

    open override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()

        visualEffectView?.effect = UIBlurEffect(style: blurStyle)
        cancelActionView?.backgroundColor = cancelButtonColor
    }
}