Notification Crash When User Accepts/Denies Request while both users are on same screen

[MichealSBingham]

Solution fixes it ... I think ?

                      //

// notificationView.swift // Swap // // Created by David Slakter on 1/21/17. // //

import Foundation

class NotificationViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

var swapRequests: [SwapRequest] = []
var acceptedRequests: [SwapRequest] = []

var blankTableMessage: UILabel?

@IBOutlet var tableView: UITableView!
@IBOutlet var activityView: UIActivityIndicatorView!

override func viewDidAppear(_ animated: Bool) {

    save(screen: .NotificationsScreen)

}

override func viewDidLoad() {
    super.viewDidLoad()

    setupViewController()
    loadNotifications()

    // Listens for reload notifications notification
    NotificationCenter.default.addObserver(self, selector: #selector(self.loadNotifications), name: .reloadNotifications, object: nil)

}

//table view
func numberOfSections(in tableView: UITableView) -> Int {

    if swapRequests.count == 0 && acceptedRequests.count == 0{

        self.tableView.backgroundView = blankTableMessage
        self.tableView.separatorStyle = UITableViewCellSeparatorStyle.none

        return 0
    }

    else{

         self.tableView.backgroundView = nil
         self.tableView.separatorStyle = UITableViewCellSeparatorStyle.singleLine

        return 2
    }
}

func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {

    var sectionName: String

    switch section {
    case 0:

        sectionName = "Swap Requests"
        break;
    case 1:
        sectionName = "Sent Requests"
        break;
    default:
        sectionName = ""
    }

    return sectionName
}
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {

    if section == 0{
        if swapRequests.count == 0{
            return 0
        }
    }

    return UITableViewAutomaticDimension

}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

    if section == 0{

        return swapRequests.count
    }
    else if section == 1{
        return acceptedRequests.count
    }
    else{
        return 0
    }
}

 func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    var cell: notificationCell

    if (indexPath.section == 0){

        cell = tableView.dequeueReusableCell(withIdentifier: "privateSwapRequest", for: indexPath) as! notificationCell;

        cell.acceptButton.tag = indexPath.row
        circularImageNoBorder(photoImageView: cell.profilePicture)
        cell.profilePicture.kf.indicatorType = .activity
        SwapUser(username: self.swapRequests[safe: indexPath.item]?._sender ?? "" ).getInformation { (error, user) in

        DispatchQueue.main.async {

            cell.profilePicture.kf.setImage(with: URL(string: (user?._profilePictureUrl)!))
            cell.usernameLabel.text = (user?._firstname)! + " " + (user?._lastname)!
            cell.timeLabel.text = (self.swapRequests[safe: indexPath.item]?._sent_at)?.timeAgo()

        }
      }
    }

    else {

            cell = tableView.dequeueReusableCell(withIdentifier: "acceptedSwapRequest", for: indexPath) as! notificationCell;

            cell.swapButton.tag = indexPath.row
            circularImageNoBorder(photoImageView: cell.profilePicture)
            cell.profilePicture.kf.indicatorType = .activity
            SwapUser(username: acceptedRequests[safe: indexPath.item]?._requested ?? "").getInformation { (error, user) in

            DispatchQueue.main.async {

                cell.profilePicture.kf.setImage(with: URL(string: (user?._profilePictureUrl)!))
                cell.usernameLabel.text = (user?._firstname)! + " " + (user?._lastname)!
                cell.timeLabel.text = (self.acceptedRequests[safe: indexPath.item]?._sent_at)?.timeAgo()
                cell.swapButton.isHidden = true
                if (self.acceptedRequests[safe: indexPath.item]?._status ?? 0).boolValue{ cell.swapButton.isHidden = false}
            }
        }
    }

    return cell

}

@IBAction func didAcceptRquest(_ sender: Any) {

    let usernameToSwapWith = swapRequests[safe: (sender as AnyObject).tag]?._sender ?? ""

    SwapUser().performActionOnSwapRequestFromUser(withUsername: usernameToSwapWith, doAccept: true, completion: {error  in

        if error == nil{
            // After Accepted or Rejected Swap Request
            // Should remove cell from table view
            DispatchQueue.main.async {

                self.swapRequests.remove(at: (sender as AnyObject).tag)
                self.tableView.reloadData()
            }
        }

    })

}
@IBAction func didDeclineRequest(_ sender: Any) {

    let usernameToSwapWith = swapRequests[safe: (sender as AnyObject).tag]?._sender ?? ""

    SwapUser().performActionOnSwapRequestFromUser(withUsername: usernameToSwapWith, doAccept: false, completion: {error  in

        if error == nil{
            // After Accepted or Rejected Swap Request
            // Should remove cell from table view
            DispatchQueue.main.async {

                self.swapRequests.remove(at: (sender as AnyObject).tag)
                self.tableView.reloadData()
            }

        }

    })

}
@IBAction func didPressSwap(_ sender: Any) {

    let usernameToSwapWith = acceptedRequests[(sender as AnyObject).tag]._requested!

    SwapUser().swap(with: usernameToSwapWith, authorizeOnViewController: self, overridePrivateAccount: true, method: .username, completion: { (error, user) in

        SwapUser().confirmSwapRequestToUser(withUsername: usernameToSwapWith)

        DispatchQueue.main.async {
            self.acceptedRequests.remove(at: (sender as AnyObject).tag)
            self.tableView.reloadData()
        }

    })

}

func setupViewController()  {

    tableView.delegate = self

    self.tableView.allowsSelection = false
    self.setupSwipeGestureRecognizers(allowCyclingThoughTabs: true)
}

func loadNotifications()  {

    tableView.reloadData()

    activityView.startAnimating()

    blankTableMessage = UILabel(frame: CGRect(x: 0, y: 0, width: self.view.bounds.size.width, height: self.view.bounds.size.height))

    blankTableMessage?.text = "No Notifications :'("
    blankTableMessage?.textColor = .black
    blankTableMessage?.textAlignment = NSTextAlignment.center
    blankTableMessage?.font = UIFont(name: "Avenir-Next", size: 20)
    blankTableMessage?.sizeToFit()
    blankTableMessage?.isHidden = true

    SwapUser(username: getUsernameOfSignedInUser()).getRequestedSwaps { (error, requests) in

        guard error == nil else {
            refreshControl.endRefreshing()
            return 
        }
        if let requests = requests{

            self.swapRequests = requests

            SwapUser().getPendingSentSwapRequests { (error, aRequests) in

                if let aRequests = aRequests{

                    DispatchQueue.main.async {

                        self.acceptedRequests = aRequests
                        self.activityView.stopAnimating()
                        self.tableView.reloadData()

                        refreshControl.endRefreshing()

                        if self.swapRequests.count > 0 || self.acceptedRequests.count > 0 {

                            self.blankTableMessage?.isHidden = true
                            self.tableView.separatorStyle = UITableViewCellSeparatorStyle.singleLine

                        } else {

                            self.blankTableMessage?.isHidden = false
                            self.tableView.separatorStyle = UITableViewCellSeparatorStyle.none

                        }

                    }

                }
            }

        }
    }

}

}

class notificationCell: UITableViewCell {

@IBOutlet var usernameLabel: UILabel!
@IBOutlet var profilePicture: UIImageView!
@IBOutlet var acceptButton: UIButton!
@IBOutlet var declineButton: UIButton!
@IBOutlet var swapButton: UIButton!
@IBOutlet var timeLabel: UILabel!

}

extension Collection where Indices.Iterator.Element == Index {

/// Returns the element at the specified index iff it is within bounds, otherwise nil.
subscript (safe index: Index) -> Generator.Element? {
    return indices.contains(index) ? self[index] : nil
}

}