table show, add, delete UI and persistence

GHFollowers/Screens/FavoriteListVC.swift

@@ -9,14 +9,125 @@
 import UIKit
 
 class FavoriteListVC: UIViewController {
+
+    let tableView = UITableView()
+    var favorites: [Follower] = []
 
     override func viewDidLoad() {
         super.viewDidLoad()
-        view.backgroundColor = .systemBlue
+        configureVC()
+        configureTableView()
+    }
+
+
+    // get new followers on screen focus
+    override func viewWillAppear(_ animated: Bool) {
+        super.viewWillAppear(animated)
+         getFavorites()
+    }
+
+
+    func configureVC() {
+        view.backgroundColor = .systemBackground
+        title = "Favorites"
+        navigationController?.navigationBar.prefersLargeTitles = true
+    }
+
+
+    func configureTableView() {
+        view.addSubview(tableView)
+        // fillup the entire window with the tableview
+        tableView.frame = view.bounds
+        tableView.rowHeight = 80
+        tableView.delegate = self
+        tableView.dataSource = self
 
-        PersistanceManager.retrieveFavorites { (result) in
-            print(result)
+        tableView.register(FavoriteCell.self, forCellReuseIdentifier: FavoriteCell.reuseID)
+    }
+
+
+    func getFavorites() {
+        PersistanceManager.retrieveFavorites { [weak self] (result) in
+            guard let self = self else { return }
+
+            switch result {
+
+            case .success(let favorites):
+
+                if favorites.isEmpty {
+                    self.showEmptyStateView(with: "No Favorites?\nAdd one on the follower screen!", in: self.view)
+                } else {
+                    // self.favorites is: var favorites: [Follower] = []
+                    // favorites is: let favorites
+                    self.favorites = favorites
+                    // restamp table with new data
+                    DispatchQueue.main.async {
+                        self.tableView.reloadData()
+                        // covers edge case where the empty state view was the one printed first
+                        self.view.bringSubviewToFront(self.tableView)
+                    }
+                }
+
+            case .failure(let error):
+                self.presentGFAlertOnMainThread(title: "Wops! Something went wrong!", message: error.rawValue, buttonTitle: "Ok")
+            }
         }
-    }    
+    }
 
 }
+
+
+
+
+extension FavoriteListVC: UITableViewDelegate, UITableViewDataSource {
+
+    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
+        return self.favorites.count
+    }
+
+    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
+        let cell = tableView.dequeueReusableCell(withIdentifier: FavoriteCell.reuseID) as! FavoriteCell
+        let favorite = favorites[indexPath.row]
+        cell.set(favorite: favorite)
+        return cell
+    }
+
+
+    // get the selected row of the tableView
+    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
+        let favorite = favorites[indexPath.row]
+        let destinationVC = FollowerListVC()
+        destinationVC.username = favorite.login
+        destinationVC.title = favorite.login
+
+        navigationController?.pushViewController(destinationVC, animated: true)
+    }
+
+
+    // SWIPE TO DELETE ROW
+    func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
+        // make sure we delete
+        guard editingStyle == .delete else { return }
+
+        // get selected user to delete
+        let favorite = favorites[indexPath.row]
+        // delete user from array that we use to populate the tableview
+        favorites.remove(at: indexPath.row)
+        // delete user from the tableView
+        tableView.deleteRows(at: [indexPath], with: .left)
+
+
+        // delete user from persistnace
+        PersistanceManager.updateWith(favorite: favorite, actionType: PersistanceActionType.remove) { [weak self] (error) in
+            guard let self = self else { return }
+
+            // if we dont have error dont do nothing and return
+            guard let error = error else { return }
+
+            // if we have an error
+            self.presentGFAlertOnMainThread(title: "Oooops. Unable to remove user 😩", message: error.rawValue, buttonTitle: "Ok")
+
+
+        }
+    }
+}