Navigator

//
//  Navigator.swift
//  tripani
//
//  Created by Jesse Lin on 11/8/17.
//  Copyright © 2017 Tripani. All rights reserved.
//

import Foundation
import UIKit
import SafariServices
import ESTabBarController_swift

protocol Navigatable {
    var navigator: Navigator! { get set }
}

class Navigator {
    static var `default`: Navigator = { return Navigator() }()
    
    private lazy var tabBarController = TPTabBarController()
    
    // MARK: - segues list
    enum Scene {
        enum Transition {
            case root(in: UIWindow)
            case navigation, modal
        }
        
        // all app scenes
        case tabs
        
        //case profileTab(ProfilePagerType)
        
        case webPage(URL)
    }
    
    // MARK: - get a single VC
    func get(segue: Scene, storyboard: UIStoryboard) -> UIViewController {
        switch segue {
            
        case .tabs:
            return tabBarController
            
//        case .profileTab(let type):
//            let vm  = ProfileInfoTabViewModel()
//            return ProfileInfoTabVC.createWith(R.storyboard.profile(), viewModel: vm, type: type)

        case .webPage(let url):
            let safari = SFSafariViewController(url: url)
            safari.hidesBottomBarWhenPushed = true
            return safari
        }
    }
    
    func show(segue: Scene, sender: UIViewController?, transition: Scene.Transition = .navigation) {
        let storyboard = sender?.storyboard ?? R.storyboard.main()
        let target = get(segue: segue, storyboard: storyboard)
        
        show(target: target, sender: sender, transition: transition)
    }
    
    // MARK: - Private Method
    
    private func show(target: UIViewController, sender: UIViewController?, transition: Scene.Transition) {
        injectNavigator(in: target)
        
        switch transition {
        case .root(in: let window):
            UIView.transition(with: window, duration: 0.5, options: .transitionFlipFromLeft, animations: {
                window.rootViewController = target
            }, completion: nil)
            return;
        default: break
        }
        
        guard let sender = sender else {
            fatalError("You need to pass in a sender for .navigation or .modal transitions")
        }
        
        if let nav = sender as? UINavigationController {
            //push root controller on navigation stack
            nav.pushViewController(target, animated: false)
            return
        }
        
        switch transition {
        case .navigation:
            if let nav = sender.navigationController {
                //add controller to navigation stack
                nav.pushViewController(target, animated: true)
            }
        case .modal:
            //present modally
            sender.present(target, animated: true, completion: nil)
        default: break
        }
    }
    
    private func injectNavigator(in target: UIViewController) {
        // view controller
        if var target = target as? Navigatable {
            target.navigator = self
            return
        }
        
        // tabs
        if let target = target as? UITabBarController, let children = target.viewControllers {
            for vc in children {
                injectNavigator(in: vc)
            }
        }
        
        // navigation controller
        if let target = target as? UINavigationController, let root = target.viewControllers.first {
            injectNavigator(in: root)
        }
    }
}