/*
Copyright 2019-2024 New Vector Ltd.

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

import Foundation

final class KeyBackupRecoverFromPassphraseViewModel: KeyBackupRecoverFromPassphraseViewModelType {
    
    // MARK: - Properties
    
    // MARK: Private
    
    private let keyBackup: MXKeyBackup
    private var currentHTTPOperation: MXHTTPOperation?
    private let keyBackupVersion: MXKeyBackupVersion
    
    // MARK: Public
    
    var passphrase: String?
    
    var isFormValid: Bool {
        return self.passphrase?.isEmpty == false
    }
    
    weak var viewDelegate: KeyBackupRecoverFromPassphraseViewModelViewDelegate?
    weak var coordinatorDelegate: KeyBackupRecoverFromPassphraseViewModelCoordinatorDelegate?
    
    // MARK: - Setup
    
    init(keyBackup: MXKeyBackup, keyBackupVersion: MXKeyBackupVersion) {
        self.keyBackup = keyBackup
        self.keyBackupVersion = keyBackupVersion
    }
    
    deinit {
        self.currentHTTPOperation?.cancel()
    }
    
    // MARK: - Public
    
    func process(viewAction: KeyBackupRecoverFromPassphraseViewAction) {
        switch viewAction {
        case .recover:
            self.recoverWithPassphrase()
        case .cancel:
            self.coordinatorDelegate?.keyBackupRecoverFromPassphraseViewModelDidCancel(self)
        case .unknownPassphrase:
            self.coordinatorDelegate?.keyBackupRecoverFromPassphraseViewModelDoNotKnowPassphrase(self)
        }
    }
    
    // MARK: - Private
    
    private func recoverWithPassphrase() {
        guard let passphrase = self.passphrase else {
            return
        }
        
        self.update(viewState: .loading)
        
        self.currentHTTPOperation = self.keyBackup.restore(self.keyBackupVersion, withPassword: passphrase, room: nil, session: nil, success: { [weak self] (_, _) in
            guard let sself = self else {
                return
            }

            // Trust on decrypt
            sself.currentHTTPOperation = sself.keyBackup.trust(sself.keyBackupVersion, trust: true, success: { [weak sself] () in
                guard let ssself = sself else {
                    return
                }

                ssself.update(viewState: .loaded)
                ssself.coordinatorDelegate?.keyBackupRecoverFromPassphraseViewModelDidRecover(ssself)

                }, failure: { [weak sself] error in
                    sself?.update(viewState: .error(error))
            })

        }, failure: { [weak self] error in
            self?.update(viewState: .error(error))
        })
    }
    
    private func update(viewState: KeyBackupRecoverFromPassphraseViewState) {
        self.viewDelegate?.keyBackupRecoverFromPassphraseViewModel(self, didUpdateViewState: viewState)
    }
}