/*

    Copyright (C) 2016 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    A 'Table View Controller' subclass that displays the data for an existing Person or for creating a new Person in the app. This class is also responsible for creating a new person to update in the PeopleTableViewController when the done button is tapped.

    Customizations: Whenever you want to add new data about a Person, you will want to add in  appropriate interface elements in the Main.storyboard and have those interface elements updated in this class to display and edit the data. To learn more you  can check out the the README file included in the app.

*/

import UIKit

class PersonViewController: UITableViewController, UITextFieldDelegate {

    // MARK: Properties

    /**

        When editing an existing person, this value is passed by 

        PeopleTableViewController in 'prepareForSegue(segue: sender:)'.

    */

    var person: Person?

    @IBOutlet weak var doneButton: UIBarButtonItem!

    @IBOutlet weak var nameTextField: UITextField!

    @IBOutlet weak var imageButton: UIButton!

    @IBOutlet weak var preferenceSlider: UISlider!

    override func viewDidLoad() {

        super.viewDidLoad()

        // Set up the views if editing an existing person.

        if let person = person {

            nameTextField.text = person.name

            imageButton.setImage(person.image, for: [])

            /*

                If they have a dog preference value set, update the slider, 

                otherwise it will use the default value set in the Main.storyboard 

                file.

            */

            if let dogPreference = person.dogPreference {

                preferenceSlider.value = dogPreference

            }

        }

    }

    // MARK: Navigation

    @IBAction func cancelTapped(_ sender: UIBarButtonItem) {

        /*

            Depending on style of presentation, this view controller needs to be 

            dismissed in two different ways. We used a modal presentation for 

            adding people, which needs to be dismissed. Editing an existing person 

            used a 'push', which requires a 'pop' to return to the previous page.

        */

        let isPresentingInAddMode = presentingViewController is UINavigationController

        if isPresentingInAddMode {

            dismiss(animated: true, completion: nil)

        }

        else {

            navigationController!.popViewController(animated: true)

        }

    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

        // Only update the person if the done button was tapped.

        if let sender = sender as? UIBarButtonItem!, sender === doneButton {

            let name = nameTextField.text

            let image = imageButton.image(for: [])

            let dogPreference = preferenceSlider.value

            /*

                Create and set the person to be passed to PeopleTableViewController 

                after the unwind segue.

            */

            person = Person(name: name, image: image, dogPreference: dogPreference)

        }

    }

    // MARK: UITextFieldDelegate

    /**

        When the user hits the return or "Done" button on a text field, we want 

        the keyboard to go away.

    */

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {

        textField.resignFirstResponder()

        return true

    }

}