//
//  CameraBridge.swift
//  anysticker
//
//  Created by Jonny Burger on 07.03.20.
//  Copyright © 2020 Facebook. All rights reserved.
//

import Foundation
import Photos
import Vision
import AVFoundation
import MobileCoreServices

public extension FileManager {
    func temporaryFileURL(fileName: String = UUID().uuidString) -> URL? {
        return URL(fileURLWithPath: NSTemporaryDirectory(), isDirectory: true).appendingPathComponent(fileName)
    }
}

let downSampling = Float(1.0)

extension CIImage {
    func resizeCI(size:CGSize) -> CIImage {
            let scale = (Double)(size.width) / (Double)(self.extent.width)
            let image = self
            
            let filter = CIFilter(name: "CILanczosScaleTransform")!
            filter.setValue(image, forKey: kCIInputImageKey)
            filter.setValue(NSNumber(value:scale), forKey: kCIInputScaleKey)
            filter.setValue(1.0, forKey:kCIInputAspectRatioKey)
            let outputImage = filter.value(forKey: kCIOutputImageKey) as! UIKit.CIImage
            
            return outputImage
    }
}

func flipImage(_ image: CGImage) -> CGImage? {
    UIGraphicsBeginImageContextWithOptions(CGSize(width: image.width, height: image.height), false, 1)
    let bitmap = UIGraphicsGetCurrentContext()!
  
    let resizedWidth = Int(image.width / 2)
    let resizedHeight = Int(image.height / 2)

    bitmap.translateBy(x: CGFloat(resizedWidth), y: CGFloat(resizedHeight))
    bitmap.scaleBy(x: -1.0, y: -1.0)

    bitmap.translateBy(x: CGFloat(-resizedWidth), y: -CGFloat(resizedHeight))
    bitmap.draw(image, in: CGRect(x: 0, y: 0, width: resizedWidth * 2, height: resizedHeight * 2))

    return bitmap.makeImage()
}

func createMatchingBackingDataWithImage(imageRef: CGImage?, orientation: UIImage.Orientation) -> CGImage? {
    var orientedImage: CGImage?

    if let imageRef = imageRef {
        let originalWidth = imageRef.width
        let originalHeight = imageRef.height
        let bitsPerComponent = imageRef.bitsPerComponent
        let bytesPerRow = imageRef.bytesPerRow

        let colorSpace = imageRef.colorSpace
        let bitmapInfo = imageRef.bitmapInfo

        var degreesToRotate: Double
        degreesToRotate = -90.0

        let radians = degreesToRotate * Double.pi / 180

        var width: Int
        var height: Int
        width = originalHeight
        height = originalWidth

        if let contextRef = CGContext(data: nil, width: width, height: height, bitsPerComponent: bitsPerComponent, bytesPerRow: bytesPerRow, space: colorSpace!, bitmapInfo: bitmapInfo.rawValue) {

            contextRef.translateBy(x: 0, y: CGFloat(height) / 2)
            
            contextRef.rotate(by: CGFloat(radians))
            contextRef.scaleBy(x: 1.0, y: -1.0)
            contextRef.translateBy(x: -CGFloat(height)/2, y: -CGFloat(width))
            contextRef.draw(imageRef, in: CGRect(x: 0, y: 0, width: originalWidth, height: originalHeight))

            orientedImage = contextRef.makeImage()
        }
    }

    return orientedImage
}

// CounterViewManager.swift
@objc(CameraBridge)
class CameraBridge: RCTViewManager, AVCapturePhotoCaptureDelegate {
  var previewView: UIView!
  var captureSession: AVCaptureSession!
  var stillImageOutput: AVCapturePhotoOutput!
  var videoPreviewLayer: AVCaptureVideoPreviewLayer!

  
  lazy var context = CIContext()

  
  func handleMatteData(_ photo: AVCapturePhoto, ssmType: AVSemanticSegmentationMatte.MatteType) -> CIImage {
        
      
        // Find the semantic segmentation matte image for the specified type.
        guard var segmentationMatte = photo.semanticSegmentationMatte(for: ssmType) else { return CIImage() }

        
        // Retrieve the photo orientation and apply it to the matte image.
        if let orientation = photo.metadata[String(kCGImagePropertyOrientation)] as? UInt32,
            let exifOrientation = CGImagePropertyOrientation(rawValue: orientation) {
            // Apply the Exif orientation to the matte image.
            
            segmentationMatte = segmentationMatte.applyingExifOrientation(exifOrientation)
        }
        
        var imageOption: CIImageOption!
        
        // Switch on the AVSemanticSegmentationMatteType value.
        switch ssmType {
        case .hair:
            imageOption = .auxiliarySemanticSegmentationHairMatte
        case .skin:
            imageOption = .auxiliarySemanticSegmentationSkinMatte
        default:
            print("This semantic segmentation type is not supported!")
            return CIImage();
        }
        
        guard let perceptualColorSpace = CGColorSpace(name: CGColorSpace.sRGB) else { return CIImage()}
        
        
        // Create a new CIImage from the matte's underlying CVPixelBuffer.
        let ciImage = CIImage( cvImageBuffer: segmentationMatte.mattingImage,
                               options: [imageOption: true,
                                         .colorSpace: perceptualColorSpace])
        return ciImage;
    }

  func photoOutput(_ output: AVCapturePhotoOutput, willCapturePhotoFor resolvedSettings: AVCaptureResolvedPhotoSettings) {
    print("settings \(NSDate().timeIntervalSince1970)")

    self.width = Int(resolvedSettings.photoDimensions.width)
    self.height = Int(resolvedSettings.photoDimensions.height)
  }
    
  func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
    print("output \(NSDate().timeIntervalSince1970)")
    output.isDepthDataDeliveryEnabled = true
    var semanticSegmentationMatteDataArray = [Data]()
    var i = 0
    guard let photoFileName = FileManager.default.temporaryFileURL(fileName: "photo.jpg") else {
      return;
    }

    let cImage = photo.cgImageRepresentation()?.takeUnretainedValue()
    let destination = CGImageDestinationCreateWithURL(photoFileName as CFURL, kUTTypeJPEG, 1, nil)!
    
    let oldCgImage = createMatchingBackingDataWithImage(imageRef: cImage, orientation: .left)
    let newCgImage = oldCgImage
    CGImageDestinationAddImage(destination, newCgImage!, nil)
    CGImageDestinationFinalize(destination)
    
    print("sending photo \(NSDate().timeIntervalSince1970)")
    DepthEvents.shared?.sendPhoto(name: "\(photoFileName.absoluteString),\(self.width),\(self.height)")
    
    recognizeFacialLandmarks(photo: photo)


    for index in output.enabledSemanticSegmentationMatteTypes.indices {
      var img = handleMatteData(photo, ssmType: output.enabledSemanticSegmentationMatteTypes[index])
      let dim =  CGSize.init(width: 720, height: 1080)
      img = img.resizeCI(size: dim)
      
      guard let perceptualColorSpace = CGColorSpace(name: CGColorSpace.sRGB) else { return}
      
      guard let imageData =  (context.jpegRepresentation(of: img,
                                        colorSpace: perceptualColorSpace,
                                        options: [.depthImage: img])) else { return }
      
      let cgImageMatte = context.createCGImage(img, from: img.extent)
      let matte = flipImage(cgImageMatte!)
      
      guard let fileName = FileManager.default.temporaryFileURL(fileName: "matte-\(i).jpg") else {
        continue;
      }
      
      let matteDestination = CGImageDestinationCreateWithURL(fileName as CFURL, kUTTypeJPEG, 1, nil)!
      CGImageDestinationAddImage(matteDestination, matte! , nil)
      CGImageDestinationFinalize(matteDestination)
      

      DepthEvents.shared?.sendMatte(name: fileName.absoluteString, type: output.enabledSemanticSegmentationMatteTypes[index].rawValue)
      i += 1
      semanticSegmentationMatteDataArray.append(imageData)
    }
  }
  
  func recognizeFacialLandmarks(photo: AVCapturePhoto) {
      var requests: [VNRequest] = []
      requests.append(VNDetectFaceLandmarksRequest(completionHandler: self.handleDetectedFaceLandmarks))
      
      guard let cgImage = photo.cgImageRepresentation() else {
          return
      }
      let imageRequestHandler = VNImageRequestHandler(cgImage: cgImage.takeUnretainedValue(),
                                                      orientation: .up,
                                                      options: [:])
      
      DispatchQueue.global(qos: .userInitiated).async {
          do {
              try imageRequestHandler.perform(requests)
          } catch let error as NSError {
              print("Failed to perform image request: \(error)")
              return
          }
      }
  }
  
  
  private var width: Int = 0
  private var height: Int = 0
  
  fileprivate func handleDetectedFaceLandmarks(request: VNRequest?, error: Error?) {
      if error != nil {
          return
      }
      // Perform drawing on the main thread.
      DispatchQueue.main.async {
          
          guard let results = request?.results as? [VNFaceObservation] else {
              return
          }
          if results.count == 0 {
              DepthEvents.shared!.sendLandmarks(args: "")
          }
          for faceObservation in results {
              guard let landmarks = faceObservation.landmarks else {
                  continue
              }
            guard let faceContour = landmarks.faceContour else  {
              continue
            }
              let hmm = faceContour.pointsInImage(imageSize: CGSize(width: Int(Float(self.width) / downSampling), height: Int(Float(self.height) / downSampling)))
            // Intentional: Image was rotated
            var points = "width:\(Float(self.height)/downSampling),height:\(Float(self.width)/downSampling)|"
            for  i in hmm {
              points = "\(points)\n\(i.y),\(i.x)"
            }
            print("sending landmarks \(NSDate().timeIntervalSince1970)")

            DepthEvents.shared!.sendLandmarks(args: points)
          }
      }
  }
  
  @objc func capture(_ resolve: RCTPromiseResolveBlock,
  rejecter reject: RCTPromiseRejectBlock) -> Void {
    print("capture \(NSDate().timeIntervalSince1970)")
    videoPreviewLayer.connection?.isEnabled = false
    let settings = AVCapturePhotoSettings(format: [AVVideoCodecKey: AVVideoCodecType.jpeg])
    settings.isDepthDataDeliveryEnabled = true
    settings.photoQualityPrioritization = .balanced
    settings.enabledSemanticSegmentationMatteTypes = [.hair, .skin]
    stillImageOutput.capturePhoto(with: settings, delegate: self)
  }

 
  override func view() -> UIView! {
    print("make view \(NSDate().timeIntervalSince1970)")
    
    self.previewView = UIView()
    
      
      guard let frontCamera = AVCaptureDevice.default(.builtInTrueDepthCamera, for: .video, position: .front) else {
            print("Unable to access back camera!")
            return UIView()
      }
      
      guard let input = try? AVCaptureDeviceInput(device: frontCamera) else {
        print("Unable to capture device")
        return UIView()
      }
      
      self.captureSession = AVCaptureSession()
      
      self.captureSession.sessionPreset = .hd1280x720

      
      self.stillImageOutput = AVCapturePhotoOutput()
      self.stillImageOutput.isHighResolutionCaptureEnabled = false
      self.stillImageOutput.connection(with: .video)?.videoOrientation = .portrait
      if self.captureSession.canAddInput(input) && self.captureSession.canAddOutput(self.stillImageOutput) {
        self.captureSession.beginConfiguration()
        self.captureSession.addInput(input)
      }
      self.captureSession.addOutput(self.stillImageOutput)
      self.stillImageOutput.isDepthDataDeliveryEnabled = true
      self.stillImageOutput.enabledSemanticSegmentationMatteTypes = self.stillImageOutput.availableSemanticSegmentationMatteTypes
      
      DispatchQueue.global().async {
        self.captureSession.commitConfiguration()
        self.captureSession.startRunning()
        DispatchQueue.main.async {
          self.videoPreviewLayer = AVCaptureVideoPreviewLayer(session: self.captureSession)
          let newActions = [
            "onOrderIn": NSNull(),
            "onOrderOut": NSNull(),
            "sublayers": NSNull(),
            "contents": NSNull(),
            "bounds": NSNull(),
          ]
          self.videoPreviewLayer.actions = newActions
          self.videoPreviewLayer.videoGravity = .resizeAspectFill
          self.videoPreviewLayer.connection?.videoOrientation = .portrait
          self.previewView.layer.addSublayer(self.videoPreviewLayer)
          self.videoPreviewLayer.layoutIfNeeded()
          self.videoPreviewLayer.frame = self.previewView.bounds
        }
      }
    print("finished view \(NSDate().timeIntervalSince1970)")

    return previewView
  }
  
  override static func requiresMainQueueSetup() -> Bool {
    return false
  }
}