//
//  LoginViewController.swift
//  MullvadVPN
//
//  Created by pronebird on 19/03/2019.
//  Copyright © 2019 Amagicom AB. All rights reserved.
//

import UIKit

class LoginViewController: UIViewController, HeaderBarViewControllerDelegate {
    
    @IBOutlet var keyboardToolbar: UIToolbar!
    @IBOutlet var accountTextField: UITextField!
    @IBOutlet var loginForm: UIView!
    @IBOutlet var loginFormWrapperBottomConstraint: NSLayoutConstraint!
    
    override var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent
    }
    
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if case .embedHeader? = SegueIdentifier.Login.from(segue: segue) {
            let headerBarController = segue.destination as? HeaderBarViewController
            headerBarController?.delegate = self
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        
        accountTextField.inputAccessoryView = keyboardToolbar
        
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(_:)), name: UIWindow.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChangeFrame(_:)), name: UIWindow.keyboardWillChangeFrameNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(_:)), name: UIWindow.keyboardWillHideNotification, object: nil)
    }
    
    // MARK: - HeaderBarViewControllerDelegate
    
    func headerBarViewControllerShouldOpenSettings(_ controller: HeaderBarViewController) {
        performSegue(withIdentifier: SegueIdentifier.Login.showSettings.rawValue, sender: self)
    }
    
    // MARK: - Keyboard notifications
    
    @objc private func keyboardWillShow(_ notification: Notification) {
        guard let keyboardFrameValue = notification.userInfo?[UIWindow.keyboardFrameEndUserInfoKey] as? NSValue else { return }
        
        makeLoginFormVisible(keyboardFrame: keyboardFrameValue.cgRectValue)
    }
    
    @objc private func keyboardWillChangeFrame(_ notification: Notification) {
        guard let keyboardFrameValue = notification.userInfo?[UIWindow.keyboardFrameEndUserInfoKey] as? NSValue else { return }
        
        makeLoginFormVisible(keyboardFrame: keyboardFrameValue.cgRectValue)
    }
    
    @objc private func keyboardWillHide(_ notification: Notification) {
        loginFormWrapperBottomConstraint.constant = 0
        view.layoutIfNeeded()
    }
    
    // MARK: - IBActions
    
    @IBAction func cancelLogin() {
        view.endEditing(true)
    }
    
    @IBAction func doLogin() {
        view.endEditing(true)
        
        // TODO: Add the code to initiate the log in
        performSegue(withIdentifier: "ShowConnect", sender: self)
    }
    
    // MARK: - Private
    
    private func makeLoginFormVisible(keyboardFrame: CGRect) {
        let convertedKeyboardFrame = view.convert(keyboardFrame, from: nil)
        let (_, remainder) = view.frame.divided(atDistance: convertedKeyboardFrame.minY, from: CGRectEdge.minYEdge)
        
        loginFormWrapperBottomConstraint.constant = remainder.height
        view.layoutIfNeeded()
    }
}