//
//  ScannerController.swift
//  Befund
//
//  Created by Artur Savitskiy on 29.08.22.
//  Copyright © 2022 MVZ Dr. Stein und Kollegen. All rights reserved.
//

import AVFoundation
import UIKit

class ScannerViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
    var captureSession: AVCaptureSession!
    var previewLayer: AVCaptureVideoPreviewLayer!

    var scanFailed: Bool = false
    var laborIsSelected: Bool = false
    
    private var isBarcodeScan = false
    
    @IBOutlet weak var btnBack: UIButton!

    enum CameraAutorizationStatus{
        case None
        case Autorized
        case Declined
    }
 
    public static func InitScannerController( scanSampleID: Bool) -> ScannerViewController
    {
        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let scanController = storyboard.instantiateViewController(identifier: "ScannerController") as ScannerViewController
        
        scanController.isBarcodeScan = scanSampleID
        
        return scanController
    }

    
    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = UIColor.gray
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)

        let status = self.checkCameraAutorizationStatus()
        if ( status == CameraAutorizationStatus.Declined) {
            failedWithAlert()
        }
        else if (status == CameraAutorizationStatus.Autorized)
        {
            StartCapture()
        }
    }

    private func StartCapture()
    {
      if (captureSession == nil)
      {
            
        captureSession = AVCaptureSession()

        guard let videoCaptureDevice = AVCaptureDevice.default(for: .video) else {
            failed()
            return }
        
        let videoInput: AVCaptureDeviceInput

        do {
            videoInput = try AVCaptureDeviceInput(device: videoCaptureDevice)
        } catch {
            failed()
            return
        }

        if (captureSession.canAddInput(videoInput)) {
            captureSession.addInput(videoInput)
        } else {
            failed()
            return
        }

        let metadataOutput = AVCaptureMetadataOutput()

        if (captureSession.canAddOutput(metadataOutput)) {
            captureSession.addOutput(metadataOutput)

            metadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
            if (isBarcodeScan)
            {
                metadataOutput.metadataObjectTypes = [.code128, .code39, .code39Mod43, .code93, .ean13, .ean8, .interleaved2of5, .itf14, .pdf417, .upce]
            }
            else
            {
                metadataOutput.metadataObjectTypes = [.qr]
            }
        } else {
            failed()
            return
        }

        previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        previewLayer.frame = view.layer.bounds
        previewLayer.videoGravity = .resizeAspectFill
        view.layer.addSublayer(previewLayer)
        
        btnBack.superview?.bringSubviewToFront(btnBack);
      }
        
      if (captureSession?.isRunning == false) {
            captureSession.startRunning()
      }

    }

    func checkCameraAutorizationStatus() -> CameraAutorizationStatus
    {
        switch AVCaptureDevice.authorizationStatus(for: .video)
        {
        case .authorized:
            return CameraAutorizationStatus.Autorized
        case .notDetermined:
            AVCaptureDevice.requestAccess(for: .video) {
                granted in
                if granted {
                    DispatchQueue.main.async
                    {
                        self.StartCapture()
                    }
                }
                else
                {
                    DispatchQueue.main.async
                    {
                        self.return2MainWindow()
                    }
                }
            }
            return CameraAutorizationStatus.None
        case .denied:
            return CameraAutorizationStatus.Declined
        case .restricted:
            return CameraAutorizationStatus.Declined
        @unknown default:
            return CameraAutorizationStatus.Declined
        }
    }
    
    func failed()
    {
        scanFailed = true
        captureSession = nil
        failedWithAlert()
    }
    
    func failedWithAlert() {
        let ac = UIAlertController(title: Core.Lang.Get(key: "LBL_SCAN_NOT_SUPPORTED"), message: Core.Lang.Get(key: "MSG_SCAN_NOT_SUPPORTED"), preferredStyle: .alert)
        ac.addAction(UIAlertAction(title: "OK", style: .default, handler: failedWithAlertOk))
        let settingsAction = UIAlertAction(title: "Einstellungen", style: .default, handler: OpenSettings)
        ac.addAction(settingsAction)
        self.present(ac, animated: true, completion: nil)
    }
    
    func OpenSettings(alert: UIAlertAction!)
    {
        guard let settingsUrl = URL(string: UIApplication.openSettingsURLString) else
        {
            return
        }
        
        if (UIApplication.shared.canOpenURL(settingsUrl)){
            UIApplication.shared.open(settingsUrl)
        }
    }

    func failedWithAlertOk(alert: UIAlertAction!) {
        #if DEBUG
        if (isBarcodeScan)
        {
            self.foundBarcode(code: "123456789ABCDE")
        }
        else
        {
            self.found(code: "befund://labor?id=LIS_SIMULATOR")
        }
            //self.found(code: "befund://labor?id=LABOR_MOENCHENGLADBACH")
        #endif
        if (!laborIsSelected)
        {
            self.return2MainWindow()
        }

    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)

        if (captureSession?.isRunning == true) {
            captureSession.stopRunning()
        }
    }

    func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
        captureSession.stopRunning()

        if let metadataObject = metadataObjects.first {
            guard let readableObject = metadataObject as? AVMetadataMachineReadableCodeObject else { return }
            guard let stringValue = readableObject.stringValue else { return }
            AudioServicesPlaySystemSound(SystemSoundID(kSystemSoundID_Vibrate))
            if (isBarcodeScan)
            {
                foundBarcode(code: stringValue)
            }
            else
            {
                found(code: stringValue)
            }

        }

        dismiss(animated: true)
    }

    func found(code: String) {
        if(code.count>0)
        {
            let posIndex = code.range(of: "id=")!.lowerBound
            let index = code.distance(from: code.startIndex, to: posIndex)
            let substr = code.dropFirst(index)
            let labID = substr.replacingOccurrences(of: "id=", with: "")
            let labor = Core.Models.Labor.GetLaborByName(id: labID)
            if (labor.id.count>0)
            {
                self.SelectLabor(labor: labor)
                self.return2MainWindow()
            }
        }
    }
    
    func foundBarcode(code: String) {
        if(code.count>0)
        {
            ViewController.currentlySelectedBarcode = code
            self.return2MainWindow()
        }
    }


    func SelectLabor(labor: Core.Models.Labor)
    {
        var settings = Core.Models.Settings.loadFromFile(atPath: Core.System.SettingsPath())
        if (settings == nil)
        {
            settings = Core.Models.Settings()
        }
        settings!.labor = labor
        laborIsSelected = settings!.save(atPath: Core.System.SettingsPath())
    }
    
    @IBAction func goBack(_ sender: Any)
    {
        self.return2MainWindow()
    }
    
    private func return2MainWindow()
    {
        self.view.endEditing(true)
        self.dismiss(animated: true, completion: nil)
    }

    override var prefersStatusBarHidden: Bool {
        return true
    }

    override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
        return .portrait
    }
}