[AltStore] Revises authentication flow with better UI

AltStore/Authentication/ReplaceCertificateViewController.swift

@@ -0,0 +1,156 @@
+//
+//  ReplaceCertificateViewController.swift
+//  AltStore
+//
+//  Created by Riley Testut on 6/5/19.
+//  Copyright © 2019 Riley Testut. All rights reserved.
+//
+
+import UIKit
+
+import AltSign
+import Roxas
+
+extension ReplaceCertificateViewController
+{
+    private enum Error: LocalizedError
+    {
+        case missingPrivateKey
+        case missingCertificate
+        
+        var errorDescription: String? {
+            switch self
+            {
+            case .missingPrivateKey: return NSLocalizedString("The certificate's private key could not be found.", comment: "")
+            case .missingCertificate: return NSLocalizedString("The certificate could not be found.", comment: "")
+            }
+        }
+    }
+}
+
+class ReplaceCertificateViewController: UITableViewController
+{
+    var replacementHandler: ((ALTCertificate?) -> Void)?
+    
+    var team: ALTTeam!
+    
+    var certificates: [ALTCertificate] {
+        get {
+            return self.dataSource.items
+        }
+        set {
+            self.dataSource.items = newValue
+        }
+    }
+    
+    private var selectedCertificate: ALTCertificate? {
+        didSet {
+            self.update()
+        }
+    }
+    
+    private lazy var dataSource = self.makeDataSource()
+    
+    override func viewDidLoad()
+    {
+        super.viewDidLoad()
+        
+        self.tableView.dataSource = self.dataSource
+        
+        self.update()
+    }
+}
+
+private extension ReplaceCertificateViewController
+{
+    func makeDataSource() -> RSTArrayTableViewDataSource<ALTCertificate>
+    {
+        let dataSource = RSTArrayTableViewDataSource<ALTCertificate>(items: [])
+        dataSource.proxy = self
+        dataSource.cellConfigurationHandler = { [weak self] (cell, certificate, indexPath) in
+            cell.textLabel?.text = certificate.name
+            cell.accessoryType = (self?.selectedCertificate == certificate) ? .checkmark : .none
+        }
+        
+        let placeholderView = RSTPlaceholderView(frame: .zero)
+        placeholderView.textLabel.text = NSLocalizedString("No Certificates", comment: "")
+        placeholderView.detailTextLabel.text = NSLocalizedString("There are no certificates associated with this team.", comment: "")
+        dataSource.placeholderView = placeholderView
+        
+        return dataSource
+    }
+    
+    func update()
+    {
+        self.navigationItem.rightBarButtonItem?.isEnabled = (self.selectedCertificate != nil)
+        
+        if self.isViewLoaded
+        {
+            self.tableView.reloadData()
+        }
+    }
+}
+
+private extension ReplaceCertificateViewController
+{
+    @IBAction func replaceCertificate(_ sender: UIBarButtonItem)
+    {
+        guard let certificate = self.selectedCertificate else { return }
+        
+        func replace()
+        {
+            sender.isIndicatingActivity = true
+            
+            ALTAppleAPI.shared.revoke(certificate, for: self.team) { (success, error) in
+                let result = Result(success, error).map { certificate }
+                
+                do
+                {
+                    let certificate = try result.get()
+                    self.replacementHandler?(certificate)
+                }
+                catch
+                {
+                    DispatchQueue.main.async {
+                        let toastView = RSTToastView(text: NSLocalizedString("Error Replacing Certificate", comment: ""), detailText: error.localizedDescription)
+                        toastView.tintColor = .altPurple
+                        toastView.show(in: self.navigationController?.view ?? self.view, duration: 2.0)
+                        
+                        sender.isIndicatingActivity = false
+                    }
+                }
+            }
+        }
+        
+        let localizedTitle = String(format: NSLocalizedString("Are you sure you want to replace %@?", comment: ""), certificate.name)
+        let localizedMessage = NSLocalizedString("Any AltStore apps currently installed with this certificate will need to be refreshed.", comment: "")
+        let localizedReplaceActionTitle = String(format: NSLocalizedString("Replace %@", comment: ""), certificate.name)
+        
+        let alertController = UIAlertController(title: localizedTitle, message: localizedMessage, preferredStyle: .actionSheet)
+        alertController.addAction(UIAlertAction(title: localizedReplaceActionTitle, style: .destructive) { (action) in
+            replace()
+        })
+        alertController.addAction(.cancel)
+        
+        self.present(alertController, animated: true, completion: nil)
+    }
+    
+    @IBAction func cancel()
+    {
+        self.replacementHandler?(nil)
+    }
+}
+
+extension ReplaceCertificateViewController
+{
+    override func tableView(_ tableView: UITableView, titleForFooterInSection section: Int) -> String?
+    {
+        return NSLocalizedString("You have reached the maximum number of development certificates. Please select a certificate to replace.", comment: "")
+    }
+    
+    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)
+    {
+        let certificate = self.dataSource.item(at: indexPath)
+        self.selectedCertificate = certificate
+    }
+}