//
//  BiometricAuthenticationViewController.swift
//  GME Remit
//
//  Created by InKwon Kim on 30/03/2019.
//Copyright © 2019 Gobal Money Express Co. Ltd. All rights reserved.
//

import UIKit
import LocalAuthentication

enum BiometricAuthenticationPolicy {
  case deviceOwnerAuthentication
  case deviceOwnerAuthenticationWithBiometrics
}

enum BiometricAuthenticationError: Error {
  case authenticationFailed
  case userCancel
  case userFallback
  case biometryNotAvailable
  case biometryNotEnrolled
  case biometryLockout
  case notBeConfigured
  
  var message: String {
    let msg: String
    
    switch self {
    case .authenticationFailed:
      msg = "There was a problem verifying your identity."
    case .userCancel:
      msg = "You pressed cancel."
    case .userFallback:
      msg = "You pressed password."
    case .biometryNotAvailable:
      msg = "FaceID & TouchID is not available."
    case .biometryNotEnrolled:
      let path = "(Setting -> FaceID(TouchID) & Passcode"
      msg = "FaceID & TouchID is not set up.\nCheck your device setting.\n\(path)"
    case .biometryLockout:
      msg = "FaceID & TouchID is locked."
    default:
      msg = "FaceID & TouchID may not be configured"
    }
    return msg
  }
}

protocol BiometricAuthenticationViewControllerDelegate: class {
  func doSelectLocalAuthenticationPolicy(
    _ viewController: BiometricAuthenticationViewController
    ) -> BiometricAuthenticationPolicy
  
  func viewController(
    _ viewController: BiometricAuthenticationViewController,
    informationTitleLabel titleLabel: UILabel,
    authenticationButton button: UIButton
  )
  
  func didComplete(_ viewController: BiometricAuthenticationViewController)
  
  func viewController(
    _ viewController: BiometricAuthenticationViewController,
    didFailWithError error: BiometricAuthenticationError,
    errorMessage: String?
  )
}

extension BiometricAuthenticationViewControllerDelegate {
  func doSelectLocalAuthenticationPolicy(
    _ viewController: BiometricAuthenticationViewController
    ) -> BiometricAuthenticationPolicy {
    return .deviceOwnerAuthenticationWithBiometrics
  }
}

final class BiometricAuthenticationViewController: UIViewController, BiometricAuthenticationViewInterface {
  
  // MARK: Properties
  var presenter: BiometricAuthenticationModuleInterface?
  weak var delegate: BiometricAuthenticationViewControllerDelegate?
  
  private var isViewDidLoad = true
  private var buttonTitle: String = "bio_press_button_title_text".localized() {
    didSet {
      biometricAuthenticationImageButton.setTitle(buttonTitle, for: .normal)
    }
  }
  // MARK: IBOutlets
  
  @IBOutlet private weak var biometricAuthenticationImageButton: UIButton!
  @IBOutlet private weak var informationLabel: UILabel!
  @IBOutlet private weak var logoImageView: UIImageView!
  
  // MARK: VC's Life cycle
  
  override func viewDidLoad() {
    super.viewDidLoad()
    self.setup()
  }
  
  override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    
    if self.isViewDidLoad {
      self.showAuthentication()
      self.isViewDidLoad = false
    }
  }
  
  // MARK: IBActions
  
  @IBAction private func authenticationButtonTouch(_ sender: Any) {
    self.showAuthentication()
  }
  
  // MARK: Other Functions
  
  private func setup() {
    // all setup should be done here
    self.setUI()
    self.delegate?.viewController(
      self,
      informationTitleLabel: self.informationLabel,
      authenticationButton: self.biometricAuthenticationImageButton
    )
    
  }
  
  private func setUI() {
    logoImageView?.image = logoImageView.image?.withRenderingMode(.alwaysTemplate)
    logoImageView.tintColor = .themeWhiteRed
    
    biometricAuthenticationImageButton.layer.cornerRadius = 5
    biometricAuthenticationImageButton.setTitle(buttonTitle, for: .normal)
    biometricAuthenticationImageButton.backgroundColor = .themeBlue
  }
  
  private func showAuthentication() {
    #if DEBUG
    DispatchQueue.main.async {
      self.delegate?.didComplete(self)
    }
    
    #else
    guard
      let isUseBiometricAuth = KeyChain.shared.get(key: .biometricAuth),
      isUseBiometricAuth == "1" else {
        let error = BiometricAuthenticationError.biometryNotAvailable
        
        self.delegate?.viewController(
          self,
          didFailWithError: error,
          errorMessage: error.message
        )
        return
    }
    self.presenter?.showBiometricAuthentication()
    #endif
  }
}