import UIKit
import Foundation

public class AlertService {

    private init() {}
    public static let shared = AlertService()

    //////////////////////////////////////////////////////////////////

    func showAlert(controller: UIViewController,
                   title: String?,
                   message: String?,
                   titleColor: UIColor = UIColor.black,
                   messageColor: UIColor = UIColor.black,
                   backgroundColor: UIColor = UIColor.white){

        let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))

        if let title = title{
            if titleColor != UIColor.black{
                let titleString = NSAttributedString(string: title, attributes: [
                    NSAttributedStringKey.font : UIFont.systemFont(ofSize: 20),
                    NSAttributedStringKey.foregroundColor : titleColor
                    ])
                alert.setValue(titleString, forKey: "attributedTitle")
            }
        }

        if let message = message{
            if messageColor != UIColor.black{
                let messageString = NSAttributedString(string: message, attributes: [
                    NSAttributedStringKey.font : UIFont.systemFont(ofSize: 16),
                    NSAttributedStringKey.foregroundColor : messageColor
                    ])
                alert.setValue(messageString, forKey: "attributedMessage")
            }
        }

        if backgroundColor != UIColor.white{
            let subview = (alert.view.subviews.first?.subviews.first?.subviews.first!)! as UIView
            subview.backgroundColor = backgroundColor
        }

        controller.present(alert, animated: true, completion: nil)
    }


    //////////////////////////////////////////////////////////////////

    func showAlertForConfirmation (controller: UIViewController,
                                   title: String?,
                                   message: String,
                                   negativeBtnText: String?,
                                   positiveBtnText: String,
                                   onCompletion: @escaping (_ isPositiveBtnCliked: Bool)-> Void){

        let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)

        let negativeBtn = UIAlertAction(title: negativeBtnText, style: .cancel){ (_) in
            onCompletion(false)
        }
        let positiveBtn  = UIAlertAction(title: positiveBtnText, style: .default) { (_) in
            onCompletion(true)
        }

        alert.addAction(negativeBtn)
        alert.addAction(positiveBtn)

        controller.present(alert, animated: true, completion: nil)
    }


    ///////////////////////////////////////////////////////////////////
    func showMessage(controller: UIViewController,
                     message: String,
                     messageColor: UIColor = UIColor.black,
                     backgroundColor:UIColor = UIColor.white){

        let alert = UIAlertController(title: nil, message: message, preferredStyle: .actionSheet)

        if backgroundColor != UIColor.white{
            let subview = (alert.view.subviews.first?.subviews.first?.subviews.first!)! as UIView
            subview.backgroundColor = backgroundColor
        }

        if messageColor != UIColor.black{
            let attributedMessage = NSAttributedString(string: message, attributes: [
                NSAttributedStringKey.foregroundColor: messageColor
                ])
            alert.setValue(attributedMessage, forKey: "attributedMessage")
        }

        controller.present(alert, animated: true, completion: nil)
        DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 1.5){
            alert.dismiss(animated: true, completion: nil)
        }
    }
}