/*

    Copyright (C) 2016 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    A view controller shown to create or update a `KeychainPasswordItem`.

*/

import UIKit

class AccountDetailsViewController: UITableViewController {

    // MARK: Dependency injection properties

    var accountName: String?

    // MARK: Interface Builder outlets

    @IBOutlet var accountNameField: UITextField!

    @IBOutlet var passwordField: UITextField!

    @IBOutlet var clearTextSwitch: UISwitch!

    @IBOutlet var saveButton: UIBarButtonItem!

    // MARK: UIViewController

    override func viewDidLoad() {

        super.viewDidLoad()

        // If an account name has been set, read any existing password from the keychain.

        if let accountName = accountName {

            do {

                let passwordItem = KeychainPasswordItem(service: KeychainConfiguration.serviceName, account: accountName, accessGroup: KeychainConfiguration.accessGroup)

                accountNameField.text = passwordItem.account

                passwordField.text = try passwordItem.readPassword()

            }

            catch {

                fatalError("Error reading password from keychain - \(error)")

            }

        }

        // Update the save button state to reflect the state of the text fields.

        updateSaveButtonState()

    }

    // MARK: Interface Builder actions

    @IBAction func textFieldChanged(_ sender: AnyObject) {

        updateSaveButtonState()

    }

    @IBAction func toggleClearText(_: AnyObject) {

        passwordField.isSecureTextEntry = !clearTextSwitch.isOn

    }

    @IBAction func save(_ sender: AnyObject) {

        // Check that text has been entered into both the account and password fields.

        guard let newAccountName = accountNameField.text, let newPassword = passwordField.text, !newAccountName.isEmpty && !newPassword.isEmpty else { return }

        // Check if we need to update an existing item or create a new one.

        do {

            if let originalAccountName = accountName {

                // Create a keychain item with the original account name.

                var passwordItem = KeychainPasswordItem(service: KeychainConfiguration.serviceName, account: originalAccountName, accessGroup: KeychainConfiguration.accessGroup)

                // Update the account name and password.

                try passwordItem.renameAccount(newAccountName)

                try passwordItem.savePassword(newPassword)

            }

            else {

                // This is a new account, create a new keychain item with the account name.

                let passwordItem = KeychainPasswordItem(service: KeychainConfiguration.serviceName, account: newAccountName, accessGroup: KeychainConfiguration.accessGroup)

                // Save the password for the new item.

                try passwordItem.savePassword(newPassword)

            }

        }

        catch {

            fatalError("Error updating keychain - \(error)")

        }

        dismiss(animated: true, completion: nil)

    }

    func updateSaveButtonState() {

        guard isViewLoaded else { return }

        // Enable the save button if both account and password fields contain text.

        if let newAccount = accountNameField.text, let newPassword = passwordField.text, !newAccount.isEmpty && !newPassword.isEmpty {

            saveButton?.isEnabled = true

        }

        else {

            saveButton?.isEnabled = false

        }

    }

}