Ring/Ring/Coordinators/AppCoordinator.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 Foundation
import UIKit
import RxSwift

/// Represents Application global navigation state
///
/// - needToOnboard: user has to onboard because he has no account
public enum AppState: State {
    case needToOnboard
}

/// This Coordinator drives the global navigation of the app (presents the UITabBarController + popups the Walkthrough)
class AppCoordinator: Coordinator, StateableResponsive {

    var rootViewController: UIViewController {
        return self.tabBarViewController
    }

    var childCoordinators = [Coordinator]()

    private let tabBarViewController = UITabBarController()
    private let injectionBag: InjectionBag
    let disposeBag = DisposeBag()

    let stateSubject = PublishSubject<State>()

    required init (with injectionBag: InjectionBag) {
        self.injectionBag = injectionBag

        self.stateSubject.subscribe(onNext: { [unowned self] (state) in
            guard let state = state as? AppState else { return }
            switch state {
            case .needToOnboard:
                self.showWalkthrough()
                break
            }
        }).disposed(by: self.disposeBag)

    }

    func start () {

        let conversationsCoordinator = ConversationsCoordinator(with: self.injectionBag)
        let contactRequestsCoordinator = ContactRequestsCoordinator(with: self.injectionBag)
        let meCoordinator = MeCoordinator(with: self.injectionBag)

        self.tabBarViewController.viewControllers = [conversationsCoordinator.rootViewController, contactRequestsCoordinator.rootViewController, meCoordinator.rootViewController]
        self.addChildCoordinator(childCoordinator: conversationsCoordinator)
        self.addChildCoordinator(childCoordinator: contactRequestsCoordinator)
        self.addChildCoordinator(childCoordinator: meCoordinator)

        self.rootViewController.rx.viewDidAppear.take(1).subscribe(onNext: { [unowned self, unowned conversationsCoordinator, unowned contactRequestsCoordinator, unowned meCoordinator] (_) in
            conversationsCoordinator.start()
            contactRequestsCoordinator.start()
            meCoordinator.start()

            // show walkthrough if needed
            if self.injectionBag.accountService.accounts.isEmpty {
                self.stateSubject.onNext(AppState.needToOnboard)
            }
        }).disposed(by: self.disposeBag)
    }

    func showDatabaseError() {
        let alertController = UIAlertController(title: L10n.Alerts.dbFailedTitle,
                                                message: L10n.Alerts.dbFailedMessage,
                                                preferredStyle: .alert)
        self.present(viewController: alertController, withStyle: .present, withAnimation: false)
    }

    private func showWalkthrough () {
        let walkthroughCoordinator = WalkthroughCoordinator(with: self.injectionBag)
        self.addChildCoordinator(childCoordinator: walkthroughCoordinator)
        let walkthroughViewController = walkthroughCoordinator.rootViewController
        self.present(viewController: walkthroughViewController, withStyle: .popup, withAnimation: false)
        walkthroughCoordinator.start()

        walkthroughViewController.rx.controllerWasDismissed.subscribe(onNext: { [weak self, weak walkthroughCoordinator] (_) in
            walkthroughCoordinator?.stateSubject.dispose()
            self?.removeChildCoordinator(childCoordinator: walkthroughCoordinator)
        }).disposed(by: self.disposeBag)
    }
}