/*

    Copyright (C) 2017 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    A view controller that demonstrates how to implement text entry using `UIAlertController`.

*/

import UIKit

class AlertFormViewController: UIViewController {

    // MARK: Properties

    private weak var secureTextAlertAction: UIAlertAction?

    // MARK: IB Actions

    @IBAction func showSimpleForm(_ sender: AnyObject) {

        let title = NSLocalizedString("A Short Title is Best", comment: "")

        let message = NSLocalizedString("A message should be a short, complete sentence.", comment: "")

        let acceptButtonTitle = NSLocalizedString("OK", comment: "")

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

        // Add two text fields for text entry.

        alertController.addTextField { textField in

            // Customize the text field.

            textField.placeholder = NSLocalizedString("Name", comment: "")

            // Specify a custom input accessory view with a descriptive title.

            let inputAccessoryView = CustomInputAccessoryView(title: NSLocalizedString("Enter your name", comment: ""))

            textField.inputAccessoryView = inputAccessoryView

        }

        alertController.addTextField { textField in

            // Customize the text field.

            textField.keyboardType = .emailAddress

            textField.placeholder = NSLocalizedString("example@example.com", comment: "")

            // Specify a custom input accessory view with a descriptive title.

            let inputAccessoryView = CustomInputAccessoryView(title: "Enter your email address")

            textField.inputAccessoryView = inputAccessoryView

        }

        // Create the actions.

        let acceptAction = UIAlertAction(title: acceptButtonTitle, style: .default) {[unowned alertController] _ in

            print("The \"Text Entry\" alert's other action occured.")

            if let enteredText = alertController.textFields?.first?.text {

                print("The text entered into the \"Text Entry\" alert's text field was \"\(enteredText)\"")

            }

        }

        /*

            The cancel action is created the the `Cancel` style and no title.

            This will allow us to capture the user clicking the menu button to

            cancel the alert while not showing a specific cancel button.

        */

        let cancelAction = UIAlertAction(title: nil, style: .cancel) { _ in

            print("The \"Text Entry\" alert's cancel action occured.")

        }

        // Add the actions.

        alertController.addAction(acceptAction)

        alertController.addAction(cancelAction)

        present(alertController, animated: true, completion: nil)

    }

    /**

        Show a secure text entry alert with "OK" and "Cancel" buttons.

        The "OK" button is only enabled when at least 5 characters have been

        entered into the text field.

    */

    @IBAction func showSecureTextEntry(_ sender: AnyObject) {

        let title = NSLocalizedString("A Short Title is Best", comment: "")

        let message = NSLocalizedString("A message should be a short, complete sentence.", comment: "")

        let acceptButtonTitle = NSLocalizedString("OK", comment: "")

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

        // Add the text field for the secure text entry.

        alertController.addTextField { textField in

            // Customize the text field.

            textField.placeholder = NSLocalizedString("Password", comment: "")

            textField.isSecureTextEntry = true

            // Specify a custom input accessory view with a descriptive title.

            let inputAccessoryView = CustomInputAccessoryView(title: "Enter at least 5 characters")

            textField.inputAccessoryView = inputAccessoryView

            /*

                Add a target that is called when the text field's text is changed so that we

                can toggle the `otherAction` enabled property based on whether the user has

                entered a long enough string.

            */

            textField.addTarget(self, action: #selector(AlertFormViewController.handleTextFieldTextDidChangeNotification(_:)), for: .editingChanged)

        }

        // Create the actions.

        let acceptAction = UIAlertAction(title: acceptButtonTitle, style: .default) { _ in

            print("The \"Secure Text Entry\" alert's other action occured.")

        }

        /*

            The cancel action is created with the `Cancel` style and no title.

            This will allow us to capture the user clicking the menu button to

            cancel the alert while not showing a specific cancel button.

        */

        let cancelAction = UIAlertAction(title: nil, style: .cancel) { _ in

            print("The \"Text Entry\" alert's cancel action occured.")

        }

        // The text field initially has no text in the text field, so we'll disable it.

        acceptAction.isEnabled = false

        /*

            Hold onto the secure text alert action to toggle the enabled / disabled 

            state when the text changed.

        */

        secureTextAlertAction = acceptAction

        // Add the actions.

        alertController.addAction(acceptAction)

        alertController.addAction(cancelAction)

        present(alertController, animated: true, completion: nil)

    }

    // MARK: Convenience

    func handleTextFieldTextDidChangeNotification(_ textField: UITextField) {

        guard let secureTextAlertAction = secureTextAlertAction else { fatalError("secureTextAlertAction has not been set") }

        // Enforce a minimum length of >= 5 characters for secure text alerts.

        let text = textField.text ?? ""

        secureTextAlertAction.isEnabled = text.characters.count >= 5

    }

}