/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

import Foundation
import SnapKit
import Shared
import SwiftKeychainWrapper

/// Delegate available for PasscodeEntryViewController consumers to be notified of the validation of a passcode.
@objc protocol PasscodeEntryDelegate: class {
    func passcodeValidationDidSucceed()
    @objc optional func userDidCancelValidation()
}

/// Presented to the to user when asking for their passcode to validate entry into a part of the app.
class PasscodeEntryViewController: BasePasscodeViewController {
    weak var delegate: PasscodeEntryDelegate?
    fileprivate var passcodePane: PasscodePane
    
    override init() {
        let authInfo = KeychainWrapper.sharedAppContainerKeychain.authenticationInfo()
        passcodePane = PasscodePane(title:nil, passcodeSize:authInfo?.passcode?.count ?? 6)
        
        super.init()
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        title = AuthenticationStrings.enterPasscodeTitle
        view.addSubview(passcodePane)
        passcodePane.snp.makeConstraints { make in
            make.bottom.left.right.equalTo(self.view)
            make.top.equalTo(self.topLayoutGuide.snp.bottom)
        }
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        passcodePane.codeInputView.delegate = self

        // Don't show the keyboard or allow typing if we're locked out. Also display the error.
        if authenticationInfo?.isLocked() ?? false {
            displayLockoutError()
            passcodePane.codeInputView.isUserInteractionEnabled = false
        } else {
            passcodePane.codeInputView.becomeFirstResponder()
        }
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        
        if authenticationInfo?.isLocked() ?? false {
            passcodePane.codeInputView.isUserInteractionEnabled = false
            passcodePane.codeInputView.resignFirstResponder()
        } else {
             passcodePane.codeInputView.becomeFirstResponder()
        }
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        self.view.endEditing(true)
    }

    override func dismissAnimated() {
        delegate?.userDidCancelValidation?()
        super.dismissAnimated()
    }
}

extension PasscodeEntryViewController: PasscodeInputViewDelegate {
    func passcodeInputView(_ inputView: PasscodeInputView, didFinishEnteringCode code: String) {
        if let passcode = authenticationInfo?.passcode, passcode == code {
            authenticationInfo?.recordValidation()
            KeychainWrapper.sharedAppContainerKeychain.setAuthenticationInfo(authenticationInfo)
            delegate?.passcodeValidationDidSucceed()
        } else {
            passcodePane.shakePasscode()
            failIncorrectPasscode(inputView)
            passcodePane.codeInputView.resetCode()

            // Store mutations on authentication info object
            KeychainWrapper.sharedAppContainerKeychain.setAuthenticationInfo(authenticationInfo)
        }
    }
}