MainVC.swift

//
//  MainVC.swift
//  MMLanScanSwiftDemo
//
//  Created by Michalis Mavris on 06/11/2016.
//  Copyright © 2016 Miksoft. All rights reserved.
//

import UIKit
import Foundation

class MainVC: UIViewController, MainPresenterDelegate, UITableViewDelegate, UITableViewDataSource {
    
    @IBOutlet weak var tableV: UITableView!
    @IBOutlet weak var navigationBarTitle: UINavigationItem!
    @IBOutlet weak var progressView: UIProgressView!
    @IBOutlet weak var tableVTopContraint: NSLayoutConstraint!
    @IBOutlet weak var scanButton: UIBarButtonItem!
  
    private var myContext = 0
    var presenter: MainPresenter!
    
    //MARK: - On Load Methods
    override func viewDidLoad() {
       
        super.viewDidLoad()

        //Init presenter. Presenter is responsible for providing the business logic of the MainVC (MVVM)
        self.presenter = MainPresenter(delegate:self)
        
        //Add observers to monitor specific values on presenter. On change of those values MainVC UI will be updated
        self.addObserversForKVO()
    }

    override func viewDidAppear(_ animated: Bool) {
        
        //Setting the title of the navigation bar with the SSID of the WiFi
        self.navigationBarTitle.title = self.presenter.ssidName
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    //MARK: - KVO Observers
    func addObserversForKVO() -> Void {
        
        self.presenter.addObserver(self, forKeyPath: "connectedDevices", options: .new, context:&myContext)
        self.presenter.addObserver(self, forKeyPath: "progressValue", options: .new, context:&myContext)
        self.presenter.addObserver(self, forKeyPath: "isScanRunning", options: .new, context:&myContext)
    }
  
    func removeObserversForKVO() -> Void {
        
        self.presenter.removeObserver(self, forKeyPath: "connectedDevices")
        self.presenter.removeObserver(self, forKeyPath: "progressValue")
        self.presenter.removeObserver(self, forKeyPath: "isScanRunning")
    }
    
    //MARK: - Button Action
    @IBAction func refresh(_ sender: Any) {
        //Shows the progress bar and start the scan. It's also setting the SSID name of the WiFi as navigation bar title
        self.showProgressBar()
        self.navigationBarTitle.title = self.presenter.ssidName
        self.presenter.scanButtonClicked()
    }
    
    //MARK: - Show/Hide Progress Bar
    func showProgressBar() -> Void {
        
        self.progressView.progress = 0
        
        UIView.animate(withDuration: 0.5, animations: {
            
            self.tableVTopContraint.constant = 40
            self.view.layoutIfNeeded()
        }, completion: nil)
    }

        
    func hideProgressBar() -> Void {
            
        UIView.animate(withDuration: 0.5, animations: {
            
            self.tableVTopContraint.constant = 0
            self.view.layoutIfNeeded()
        }, completion: nil)
            
    }
    
    //MARK: - Presenter Delegates
    //The delegates methods from Presenters.These methods help the MainPresenter to notify the MainVC for any kind of changes
    func mainPresenterIPSearchFinished() {
        
        self.hideProgressBar()
        self.showAlert(title: "Scan Finished", message: "Number of devices connected to the Local Area Network : \(self.presenter.connectedDevices.count)")
    }
    
    func mainPresenterIPSearchCancelled() {

        self.hideProgressBar()
        self.tableV.reloadData()
    }
    
    func mainPresenterIPSearchFailed() {
        
        self.hideProgressBar()
        self.showAlert(title: "Failed to scan", message: "Please make sure that you are connected to a WiFi before starting LAN Scan")
    }
    
    //MARK: - Alert Controller
    func showAlert(title:String, message: String) {
    
        let alertController = UIAlertController(title: title, message: message, preferredStyle: UIAlertController.Style.alert)
     
        let okAction = UIAlertAction(title: "OK", style: UIAlertAction.Style.default) { (result : UIAlertAction) -> Void in }
        
        alertController.addAction(okAction)
        
        self.present(alertController, animated: true, completion: nil)
    }
    
    //MARK: - UITableView Delegates
    func numberOfSections(in tableView: UITableView) -> Int {
        
        return 1
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        
        return self.presenter.connectedDevices!.count
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        
       
        let cell = tableView.dequeueReusableCell(withIdentifier: "DeviceCell", for: indexPath) as! DeviceCell
        
        let device = self.presenter.connectedDevices[indexPath.row] 
        
        cell.ipLabel.text = device.ipAddress
        cell.hostnameLabel.text = device.hostname
        
        //Wont work for iOS 11
        //cell.macAddressLabel.text = device.macAddress
        //cell.brandLabel.text = device.isLocalDevice ? "Your device" : device.brand
        
        return cell
    }
    
    //MARK: - KVO
    //This is the KVO function that handles changes on MainPresenter
    override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {

        if (context == &myContext) {
        
            switch keyPath! {
            case "connectedDevices":
                self.tableV.reloadData()
            case "progressValue":
                self.progressView.progress = self.presenter.progressValue
            case "isScanRunning":
                let isScanRunning = change?[.newKey] as! BooleanLiteralType
                self.scanButton.image = isScanRunning ? #imageLiteral(resourceName: "stopBarButton") : #imageLiteral(resourceName: "refreshBarButton")
            default:
                print("Not valid key for observing")
            }
            
        }
    }
    
    //MARK: - Deinit
    deinit {
        
        self.removeObserversForKVO()
    }
    
    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    */

}