/*
Copyright 2019-2024 New Vector Ltd.

SPDX-License-Identifier: AGPL-3.0-only
Please see LICENSE in the repository root for full details.
 */

import UIKit

@objc protocol SignOutAlertPresenterDelegate: AnyObject {
    func signOutAlertPresenterDidTapSignOutAction(_ presenter: SignOutAlertPresenter)
    func signOutAlertPresenterDidTapBackupAction(_ presenter: SignOutAlertPresenter)
}

@objcMembers
final class SignOutAlertPresenter: NSObject {
    
    // MARK: - Properties
    
    // MARK: Private
    
    private weak var presentingViewController: UIViewController?
    private weak var sourceView: UIView?
    
    // MARK: Public
    
    weak var delegate: SignOutAlertPresenterDelegate?
    
    // MARK: - Public
    
    func present(for keyBackupState: MXKeyBackupState,
                 areThereKeysToBackup: Bool,
                 from viewController: UIViewController,
                 sourceView: UIView?,
                 animated: Bool) {
        self.sourceView = sourceView
        self.presentingViewController = viewController
        
        guard areThereKeysToBackup else {
            // If there is no keys to backup do not mention key backup and present same alert as if we had an existing backup.
            self.presentExistingBackupAlert(animated: animated)
            return
        }
                
        switch keyBackupState {
        case MXKeyBackupStateUnknown, MXKeyBackupStateDisabled, MXKeyBackupStateCheckingBackUpOnHomeserver:
            self.presentNonExistingBackupAlert(animated: animated)
        case MXKeyBackupStateWillBackUp, MXKeyBackupStateBackingUp:
            self.presentBackupInProgressAlert(animated: animated)
        default:
            self.presentExistingBackupAlert(animated: animated)
        }
    }
    
    // MARK: - Private
    
    private func presentExistingBackupAlert(animated: Bool) {
        let alertController = UIAlertController(title: VectorL10n.signOutExistingKeyBackupAlertTitle,
                                               message: nil,
                                               preferredStyle: .actionSheet)
        
        let signoutAction = UIAlertAction(title: VectorL10n.signOutExistingKeyBackupAlertSignOutAction, style: .destructive) { (_) in
            self.delegate?.signOutAlertPresenterDidTapSignOutAction(self)
        }
        
        let cancelAction = UIAlertAction(title: VectorL10n.cancel, style: .cancel)
        
        alertController.addAction(signoutAction)
        alertController.addAction(cancelAction)
        
        self.present(alertController: alertController, animated: animated)
    }
    
    private func presentNonExistingBackupAlert(animated: Bool) {
        let alertController = UIAlertController(title: VectorL10n.signOutNonExistingKeyBackupAlertTitle,
                                               message: nil,
                                               preferredStyle: .actionSheet)
        
        let doNotWantKeyBackupAction = UIAlertAction(title: VectorL10n.signOutNonExistingKeyBackupAlertDiscardKeyBackupAction, style: .destructive) { (_) in
            self.presentNonExistingBackupSignOutConfirmationAlert(animated: true)
        }
        
        let setUpKeyBackupAction = UIAlertAction(title: VectorL10n.signOutNonExistingKeyBackupAlertSetupSecureBackupAction, style: .default) { (_) in
            self.delegate?.signOutAlertPresenterDidTapBackupAction(self)
        }
        
        let cancelAction = UIAlertAction(title: VectorL10n.cancel, style: .cancel)
        
        alertController.addAction(doNotWantKeyBackupAction)
        alertController.addAction(setUpKeyBackupAction)
        alertController.addAction(cancelAction)
        
        self.present(alertController: alertController, animated: animated)
    }
    
    private func presentNonExistingBackupSignOutConfirmationAlert(animated: Bool) {
        let alertController = UIAlertController(title: VectorL10n.signOutNonExistingKeyBackupSignOutConfirmationAlertTitle,
                                               message: VectorL10n.signOutNonExistingKeyBackupSignOutConfirmationAlertMessage,
                                               preferredStyle: .alert)
        
        let signOutAction = UIAlertAction(title: VectorL10n.signOutNonExistingKeyBackupSignOutConfirmationAlertSignOutAction, style: .destructive) { (_) in
            self.delegate?.signOutAlertPresenterDidTapSignOutAction(self)
        }
        
        let setUpKeyBackupAction = UIAlertAction(title: VectorL10n.signOutNonExistingKeyBackupSignOutConfirmationAlertBackupAction, style: .default) { (_) in
            self.delegate?.signOutAlertPresenterDidTapBackupAction(self)
        }
        
        alertController.addAction(signOutAction)
        alertController.addAction(setUpKeyBackupAction)
        
        self.present(alertController: alertController, animated: animated)
    }
    
    private func presentBackupInProgressAlert(animated: Bool) {
        let alertController = UIAlertController(title: VectorL10n.signOutKeyBackupInProgressAlertTitle,
                                               message: nil,
                                               preferredStyle: .actionSheet)
        
        let discardKeyBackupAction = UIAlertAction(title: VectorL10n.signOutKeyBackupInProgressAlertDiscardKeyBackupAction, style: .destructive) { (_) in
            self.delegate?.signOutAlertPresenterDidTapSignOutAction(self)
        }
        
        let cancelAction = UIAlertAction(title: VectorL10n.signOutKeyBackupInProgressAlertCancelAction, style: .cancel)
        
        alertController.addAction(discardKeyBackupAction)
        alertController.addAction(cancelAction)
        
        self.present(alertController: alertController, animated: animated)
    }
    
    private func present(alertController: UIAlertController, animated: Bool) {
        
        // Configure source view when alert controller is presented with a popover
        if let sourceView = self.sourceView, let popoverPresentationController = alertController.popoverPresentationController {
            popoverPresentationController.sourceView = sourceView
            popoverPresentationController.sourceRect = sourceView.bounds
            popoverPresentationController.permittedArrowDirections = [.down, .up]
        }
        
        self.presentingViewController?.present(alertController, animated: animated, completion: nil)
    }
}