//
//  CardsScanViewController.swift
//  Wallet
//
//  Created by Alexandr Serpokrylow on 10.02.2022.
//  Copyright © 2022 AM. All rights reserved.
//

import AVFoundation
import UIKit

public protocol CardsScanViewControllerDelegate: AnyObject {
    func creditCardScannerViewControllerDidCancel(_ viewController: CardsScanViewController)
    func creditCardScannerViewController(_ viewController: CardsScanViewController, didErrorWith error: CreditCardScannerError)
    func creditCardScannerViewController(_ viewController: CardsScanViewController, didFinishWith card: CreditCard)
}

open class CardsScanViewController: UIViewController {
    
    @IBOutlet weak var cameraView: CameraView!
    @IBOutlet weak var descriptionLabel: UILabel!
    
    private lazy var analyzer = ImageAnalyzer(delegate: self)

    weak var delegate: CardsScanViewControllerDelegate?

    override open func viewDidLoad() {
        super.viewDidLoad()
        configureView()
    }

    override open func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        cameraView.setupRegionOfInterest()
    }
    
    private func configureView() {
      
        cameraView.delegate = self
        descriptionLabel.textAlignment = .center
        
        AVCaptureDevice.authorize { [weak self] authoriazed in
            guard let strongSelf = self else {
                return
            }
            guard authoriazed else {
                strongSelf.delegate?.creditCardScannerViewController(strongSelf, didErrorWith: CreditCardScannerError(kind: .authorizationDenied, underlyingError: nil))
                return
            }
            strongSelf.cameraView.setupCamera()
        }
    }
    
    @IBAction func cancel(_ sender: Any) {
        delegate?.creditCardScannerViewControllerDidCancel(self)
    }
}
extension CardsScanViewController: CameraViewDelegate {
    internal func didCapture(image: CGImage) {
        analyzer.analyze(image: image)
    }

    internal func didError(with error: CreditCardScannerError) {
        DispatchQueue.main.async { [weak self] in
            guard let strongSelf = self else { return }
            strongSelf.delegate?.creditCardScannerViewController(strongSelf, didErrorWith: error)
            strongSelf.cameraView.stopSession()
        }
    }
}

extension CardsScanViewController: ImageAnalyzerProtocol {
    internal func didFinishAnalyzation(with result: Result<CreditCard, CreditCardScannerError>) {
        switch result {
        case let .success(creditCard):
            DispatchQueue.main.async { [weak self] in
                guard let strongSelf = self else { return }
                strongSelf.cameraView.stopSession()
                
                if let number = creditCard.number, CCValidator.validate(creditCardNumber: Cards.Model.cleaned(number: number), validatePrefix: false, validateLength: true, useLuhnAlgorithm: true) {
                    strongSelf.delegate?.creditCardScannerViewController(strongSelf, didFinishWith: creditCard)
                    strongSelf.delegate?.creditCardScannerViewControllerDidCancel(strongSelf)
                } else {
                    Alert.error(text: L10n.Cards.Card.Recognize.notValid)
                    self?.dismiss(animated: true)
                }
            }

        case let .failure(error):
            DispatchQueue.main.async { [weak self] in
                guard let strongSelf = self else { return }
                strongSelf.cameraView.stopSession()
                strongSelf.delegate?.creditCardScannerViewController(strongSelf, didErrorWith: error)
                strongSelf.delegate?.creditCardScannerViewControllerDidCancel(strongSelf)
            }
        }
    }
}

public extension CardsScanViewControllerDelegate where Self: UIViewController {
    func creditCardScannerViewControllerDidCancel(_ viewController: CardsScanViewController) {
        viewController.dismiss(animated: true)
    }
}

extension AVCaptureDevice {
    static func authorize(authorizedHandler: @escaping ((Bool) -> Void)) {
        let mainThreadHandler: ((Bool) -> Void) = { isAuthorized in
            DispatchQueue.main.async {
                authorizedHandler(isAuthorized)
            }
        }

        switch authorizationStatus(for: .video) {
        case .authorized:
            mainThreadHandler(true)
        case .notDetermined:
            requestAccess(for: .video, completionHandler: { granted in
                mainThreadHandler(granted)
})
        default:
            mainThreadHandler(false)
        }
    }
}