CustomAlertController

//
//  KMAlertViewController.swift
//
//  Created by Kazi Abdullah Al Mamun on 13/2/20.
//  Copyright © 2020 Kazi Abdullah Al Mamun. All rights reserved.
//
import UIKit

class KMAlertViewController: UIViewController {

    private var titleMsg: String?
    private var message: String?
    private var okAction: ((KMAlertViewController) -> Void)?
    private var cancelAction: ((KMAlertViewController) -> Void)?

    private let containerView: UIView = {
        let view = UIView()
        view.backgroundColor = #colorLiteral(red: 0.9607843137, green: 0.9607843137, blue: 0.9607843137, alpha: 1)
        view.setCornerRadius(5)
        return view
    }()

    private lazy var titleLabel: UILabel = {
        let label = UILabel()
        label.textColor = #colorLiteral(red: 0.4588235294, green: 0.4588235294, blue: 0.4588235294, alpha: 1)
        label.font = UIFont.systemFont(ofSize: 24)
        label.text = self.titleMsg ?? ""
        label.numberOfLines = 1
        label.textAlignment = .center
        return label
    }()

    private lazy var messageLabel: UILabel = {
        let label = UILabel()
        label.textColor = #colorLiteral(red: 0.4745098039, green: 0.4745098039, blue: 0.4745098039, alpha: 1)
        label.font = UIFont.systemFont(ofSize: 18)
        label.text = self.message ?? ""
        label.numberOfLines = 0
        label.textAlignment = .center
        return label
    }()

    private lazy var okBtn: UIButton = {
        let btn = UIButton()
        btn.setTitle("Ok", for: .normal)
        btn.setTitleColor(.white, for: .normal)
        btn.backgroundColor = #colorLiteral(red: 0.2470588235, green: 0.662745098, blue: 0.9607843137, alpha: 1)
        btn.setCornerRadius(5)
        btn.addTarget(self, action: #selector(okBtnAction(_:)), for: .touchUpInside)
        return btn
    }()

    private let cancelBtn: UIButton = {
        let btn = UIButton()
        btn.setTitle("Cancel", for: .normal)
        btn.setTitleColor(#colorLiteral(red: 0.6784313725, green: 0.6784313725, blue: 0.6784313725, alpha: 1), for: .normal)
        btn.backgroundColor = #colorLiteral(red: 0.9411764706, green: 0.9411764706, blue: 0.9411764706, alpha: 1)
        btn.setCornerRadius(5)
        btn.addTarget(self, action: #selector(cancelBtnAction(_:)), for: .touchUpInside)
        return btn
    }()

    override func loadView() {

        view = UIView()
        view.backgroundColor = #colorLiteral(red: 0, green: 0, blue: 0, alpha: 0.5135916096)

        view.addSubview(containerView)
        containerView.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            containerView.centerYAnchor.constraint(equalTo: view.centerYAnchor),
            containerView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            containerView.widthAnchor.constraint(equalTo: view.widthAnchor, multiplier: 0.8)
        ])

        containerView.addSubview(titleLabel)
        titleLabel.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            titleLabel.topAnchor.constraint(equalTo: containerView.topAnchor, constant: 16),
            titleLabel.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 32),
            titleLabel.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -32)
        ])

        containerView.addSubview(messageLabel)
        messageLabel.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            messageLabel.topAnchor.constraint(equalTo: titleLabel.bottomAnchor, constant: 12),
            messageLabel.centerXAnchor.constraint(equalTo: titleLabel.centerXAnchor),
            messageLabel.widthAnchor.constraint(equalTo: titleLabel.widthAnchor, multiplier: 1)
        ])

        let btnStackView = UIStackView()
        btnStackView.axis = .horizontal
        btnStackView.spacing = 16
        btnStackView.distribution = .fillEqually
        btnStackView.addArrangedSubview(cancelBtn)
        btnStackView.addArrangedSubview(okBtn)
        containerView.addSubview(btnStackView)
        btnStackView.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            btnStackView.heightAnchor.constraint(equalToConstant: 50),
            btnStackView.topAnchor.constraint(equalTo: messageLabel.bottomAnchor, constant: 40),
            btnStackView.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 16),
            btnStackView.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -16),
            btnStackView.bottomAnchor.constraint(equalTo: containerView.bottomAnchor, constant: -16)
        ])

    }

    init(title: String?, message: String?) {
        self.titleMsg = title
        self.message = message
        super.init(nibName: nil, bundle: nil)
        self.modalPresentationStyle = .overFullScreen
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

    //Mark: Member Functions

    public func addAction(for event: ActionEvent, action: @escaping (KMAlertViewController) -> Void) {
        switch event {
        case .Ok:
            self.okAction = action
        case .Cancel:
            self.cancelAction = action
        }
    }

    //Mark: Actions

    @objc func okBtnAction(_ sendr: UIButton) {
        guard let okAction = self.okAction else {
            self.dismiss(animated: false)
            return
        }
        okAction(self)
    }

    @objc func cancelBtnAction(_ sendr: UIButton) {
        guard let action = self.cancelAction else {
            self.dismiss(animated: false)
            return
        }
        action(self)
    }
}

extension KMAlertViewController {
    public enum ActionEvent {
        case Ok
        case Cancel
    }
}