Changing Database Encryption Key

import UIKit
 
class ViewController: UIViewController {
 
    // Declare user interface elements
    @IBOutlet weak var keyTextField: UITextField!
    @IBOutlet weak var openDatabaseButton: UIButton!
    @IBOutlet weak var rekeyDatabaseButton: UIButton!
    @IBOutlet weak var resultTextView: UITextView!
 
    // Execute methods of user interface display cycle
    override func viewDidLoad() {
        super.viewDidLoad()
        self.deactivateViews()
        self.initializeFramework()
        self.auth {
            self.activateViews()
            self.resultTextView.text = "Authentication success"
        }
    }
 
    // Set methods to handle events initialized by the user from user interface
    @IBAction func openDatabasePressed(_ sender: UIButton) {
        let databaseName = "database.sqlite"
        self.closeDatabase(databaseName)
        let key = self.keyTextField.text ?? ""
        self.resultTextView.text = "Open base with key \"\(key)\" success: \(self.openDatabase(databaseName, key: key))"
    }
    @IBAction func rekeyDatabasePressed(_ sender: UIButton) {
        let databaseName = "database.sqlite"
        let newKey = self.keyTextField.text ?? ""
        self.resultTextView.text = "Rekey base with new key \"\(newKey)\" success: \(self.rekeyDatabase(databaseName, newKey: newKey))"
    }
 
    // Initialize framework
    private func initializeFramework() {
        let apiVersion: String = "v1"
        let host: String = "http://testmasterfmp.fsight.cloud/"
        let environment: String = "DocumentationExampleEnv"
        let project: String = "DocumentationExampleProj"
        let device: String = (UIDevice.current.identifierForVendor?.uuidString)!
        HHFWController.sharedInstance().initWithCredentials(
            apiVersion,
            host: host,
            environment: environment,
            project: project,
            device: device
        )
    }
 
    // Authenticate
    private func auth(completion: @escaping ()->()) {
        let username: String = "test"
        let password: String = "test123"
        HHFWController.sharedInstance().auth(username, password: password){ (jsonResult) in
            if let jsonDict = jsonResult as? NSDictionary,
                let status = jsonDict["status"] as? String, status == "ok" {
                print("Auth success")
                completion()
            } else {
                print("Auth error")
            }
        }
    }
 
    // Open or create a database
    private func openDatabase(_ databaseName: String, key: String) -> Bool {
        let fullDatabaseURL = self.getURL(for: databaseName)
        return HHFWController.sharedInstance().openBase(fullDatabaseURL.path, key: key)
    }
 
    // Change database encryption key
    private func rekeyDatabase(_ databaseName: String, newKey: String) -> Bool {
        let fullDatabaseURL = self.getURL(for: databaseName)
        return HHFWController.sharedInstance().rekeyBase(fullDatabaseURL.path, newKey: newKey)
    }
 
    // Close database
    private func closeDatabase(_ databaseName: String) -> Bool {
        let fullDatabaseURL = self.getURL(for: databaseName)
        return HHFWController.sharedInstance().closeBase(fullDatabaseURL.path)
    }
 
    // Execute auxiliary methods
    private func getURL(for fileName: String) -> URL {
        let paths: [URL] = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
        let fileURL: URL = paths[0].appendingPathComponent(fileName)
        return fileURL
    }
 
    // Set methods for changing user interface display elements
    private func deactivateViews() {
        self.keyTextField.isEnabled = false
        self.openDatabaseButton.isEnabled = false
        self.rekeyDatabaseButton.isEnabled = false
    }
    private func activateViews() {
        self.keyTextField.isEnabled = true
        self.openDatabaseButton.isEnabled = true
        self.rekeyDatabaseButton.isEnabled = true
    }
}