Ring/Ring/Features/Walkthrough/CreateAccount/CreateAccountViewController.swift

/*
 *  Copyright (C) 2017 Savoir-faire Linux Inc.
 *
 *  Author: Thibault Wittemberg <thibault.wittemberg@savoirfairelinux.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA.
 */

import UIKit
import Reusable
import RxSwift
import PKHUD

class CreateAccountViewController: UIViewController, StoryboardBased, ViewModelBased {

    // MARK: outlets
    @IBOutlet weak var createAccountButton: DesignableButton!
    @IBOutlet weak var createAccountTitle: UILabel!
    @IBOutlet weak var registerUsernameHeightConstraint: NSLayoutConstraint! {
        didSet {
            self.registerUsernameHeightConstraintConstant = registerUsernameHeightConstraint.constant
        }
    }
    @IBOutlet weak var usernameSwitch: UISwitch!
    @IBOutlet weak var registerUsernameView: UIView!
    @IBOutlet weak var registerUsernameLabel: UILabel!
    @IBOutlet weak var registerUsernameErrorLabel: UILabel!
    @IBOutlet weak var passwordTextField: DesignableTextField!
    @IBOutlet weak var confirmPasswordTextField: DesignableTextField!
    @IBOutlet weak var passwordErrorLabel: UILabel!
    @IBOutlet weak var usernameTextField: DesignableTextField!
    @IBOutlet weak var scrollView: UIScrollView!

    // MARK: members
    private let disposeBag = DisposeBag()
    var viewModel: CreateAccountViewModel!
    var registerUsernameHeightConstraintConstant: CGFloat = 0.0

    // MARK: functions
    override func viewDidLoad() {
        super.viewDidLoad()

        // L10n
        self.applyL10n()

        // Bind ViewModel to View
        self.bindViewModelToView()

        // Bind Voew to ViewModel
        self.bindViewToViewModel()

        // handle keyboard
        self.adaptToKeyboardState(for: self.scrollView, with: self.disposeBag)
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        UIApplication.shared.statusBarStyle = .default
    }

    private func applyL10n() {
        self.createAccountTitle.text = self.viewModel.createAccountTitle
        self.createAccountButton.setTitle(self.viewModel.createAccountButton, for: .normal)
        self.usernameTextField.placeholder = self.viewModel.usernameTitle
        self.passwordTextField.placeholder = self.viewModel.passwordTitle
        self.confirmPasswordTextField.placeholder = self.viewModel.confirmPasswordTitle
    }

    private func bindViewModelToView() {
        // handle username registration visibility
        self.viewModel.registerUsername.asObservable()
            .observeOn(MainScheduler.instance)
            .subscribe(onNext: { [unowned self] (isOn) in
            UIView.animate(withDuration: 0.3, animations: {
                if isOn {
                    self.registerUsernameHeightConstraint.constant = self.registerUsernameHeightConstraintConstant
                    self.registerUsernameView.alpha = 1.0
                } else {
                    self.registerUsernameHeightConstraint.constant = 0
                    self.registerUsernameView.alpha = 0.0
                }

                self.view.layoutIfNeeded()
            })
        }).disposed(by: self.disposeBag)

        // handle Create Account Button state
        self.viewModel.canAskForAccountCreation.bind(to: self.createAccountButton.rx.isEnabled).disposed(by: self.disposeBag)

        // handle password error
        self.viewModel.passwordValidationState.map { $0.isValidated }
            .skipUntil(self.passwordTextField.rx.controlEvent(UIControlEvents.editingDidEnd))
            .bind(to: self.passwordErrorLabel.rx.isHidden).disposed(by: self.disposeBag)
        self.viewModel.passwordValidationState.map { $0.message }
            .skipUntil(self.passwordTextField.rx.controlEvent(UIControlEvents.editingDidEnd))
            .bind(to: self.passwordErrorLabel.rx.text).disposed(by: self.disposeBag)

        // handle registration error
        self.viewModel.usernameValidationState.asObservable().map { $0.isAvailable }
            .skipUntil(self.usernameTextField.rx.controlEvent(UIControlEvents.editingDidBegin))
            .bind(to: self.registerUsernameErrorLabel.rx.isHidden).disposed(by: self.disposeBag)
        self.viewModel.usernameValidationState.asObservable().map { $0.message }
            .skipUntil(self.usernameTextField.rx.controlEvent(UIControlEvents.editingDidBegin))
            .bind(to: self.registerUsernameErrorLabel.rx.text).disposed(by: self.disposeBag)

        // handle creation state
        self.viewModel.createState
            .observeOn(MainScheduler.instance)
            .subscribe(onNext: { [weak self] (state) in
            switch state {
            case .started:
                self?.showAccountCreationInProgress()
            case .success:
                self?.hideAccountCreationHud()
            default:
                self?.hideAccountCreationHud()
            }
        }, onError: { [weak self] (error) in
            self?.hideAccountCreationHud()

            if let error = error as? AccountCreationError {
                self?.showAccountCreationError(error: error)
            }
        }).disposed(by: self.disposeBag)
    }

    private func bindViewToViewModel() {
        // Bind View Outlets to ViewModel
        self.usernameSwitch.rx.isOn.bind(to: self.viewModel.registerUsername).disposed(by: self.disposeBag)
        self.usernameTextField.rx.text.orEmpty.throttle(3, scheduler: MainScheduler.instance).distinctUntilChanged().bind(to: self.viewModel.username).disposed(by: self.disposeBag)
        self.passwordTextField.rx.text.orEmpty.bind(to: self.viewModel.password).disposed(by: self.disposeBag)
        self.confirmPasswordTextField.rx.text.orEmpty.bind(to: self.viewModel.confirmPassword).disposed(by: self.disposeBag)

        // Bind View Actions to ViewModel
        self.createAccountButton.rx.tap.subscribe(onNext: { [unowned self] in
            DispatchQueue.main.async {
                self.showAccountCreationInProgress()
            }
            DispatchQueue.global(qos: .background).async {
                self.viewModel.createAccount()
            }
        }).disposed(by: self.disposeBag)
    }

    private func showAccountCreationInProgress() {
        HUD.show(.labeledProgress(title: L10n.CreateAccount.waitCreateAccountTitle, subtitle: nil))
    }

    private func showAccountCreationSuccess() {
        HUD.flash(.labeledSuccess(title: L10n.Alerts.accountAddedTitle, subtitle: nil), delay: Durations.alertFlashDuration.value)
    }

    private func hideAccountCreationHud() {
        HUD.hide()
    }

    private func showAccountCreationError(error: AccountCreationError) {
        let alert = UIAlertController.init(title: error.title,
                                           message: error.message,
                                           preferredStyle: .alert)
        alert.addAction(UIAlertAction.init(title: L10n.Global.ok, style: .default, handler: nil))
        self.present(alert, animated: true, completion: nil)
    }
}