CA Animation Complete

    private let colorArray = ["FBDA75", "FFCCAC", "FFD4E4", "DCDEF9"]
    private let imageArray = ["image-1", "image-2", "image-3", "image-4"]
    private var timer: Timer?
    private var iconsInterval: Int = 0
    
    // for image animation
    private var imageView1: UIImageView!
    private var imageView2: UIImageView!
    private var imageViewChangeflag = 1
    private var initalPosition: CGPoint!
    private var centerPosition: CGPoint!
    private var finalPosition: CGPoint!
    
    private var imageSize: CGFloat = 80
    
    private func setupViews() {
        imageBackgroundView.layer.cornerRadius = imageBackgroundView.frame.size.width/2
        imageBackgroundView.backgroundColor = UIColor(hexString: colorArray.first)
        
        let initialFrame = CGRect(x: (self.imageBackgroundView.bounds.width - imageSize)/2, y: imageBackgroundView.bounds.height + 20, width: imageSize, height: imageSize)
        let centerFrame = CGRect(x: (self.imageBackgroundView.bounds.width - imageSize)/2, y: (self.imageBackgroundView.bounds.height - imageSize)/2, width: imageSize, height: imageSize)
        
        imageView1 = UIImageView(frame: centerFrame)
        imageView1.contentMode = .scaleAspectFill
        imageBackgroundView.addSubview(imageView1)
        
        imageView2 = UIImageView(frame: initialFrame)
        imageView2.contentMode = .scaleAspectFill
        imageBackgroundView.addSubview(imageView2)
        
        initalPosition = self.imageView2.layer.position
        centerPosition = self.imageView1.layer.position
        finalPosition = CGPoint(x: imageView1.layer.position.x, y: imageView1.layer.position.y - imageBackgroundView.bounds.height - 20)
    }
    
    func configure() {
        setDashImage(forImageId: imageArray[1], onImageView: imageView1)
        self.iconsInterval = 1
        setDashImage(forImageId: imageArray[1], onImageView: imageView2)
        self.iconsInterval = 2
    }
    
    private func setDashImage(forImageId imageId: String, onImageView imageView: UIImageView) {
        imageView.image = UIImage(named: imageId)
    }
    
    private func addCardAnimation() {
        DispatchQueue.main.async { [weak self] in
            guard let selfRef = self else {
                return
            }
            selfRef.timer?.invalidate()
            selfRef.timer = Timer.scheduledTimer(timeInterval: 3.0, target: selfRef, selector: #selector(selfRef.startImageAnimation), userInfo: nil, repeats: true)
        }
    }

    @objc private func startImageAnimation() {
        self.startBackColorAnimation()
        if imageViewChangeflag == 1 {
            addAnimation(firstImageView: imageView1, secondImageView: imageView2)
        } else {
            addAnimation(firstImageView: imageView2, secondImageView: imageView1)
        }
        imageViewChangeflag = -imageViewChangeflag
    }
    
    private func addAnimation(firstImageView: UIImageView, secondImageView: UIImageView) {
        let basicAnimation1 = getBasicAnimation(withInitialPostion: centerPosition, finalPos: finalPosition)
        firstImageView.layer.add(basicAnimation1, forKey: "position")        
        let basicAnimation2 = self.getBasicAnimation(withInitialPostion: self.initalPosition, finalPos: self.centerPosition)
        secondImageView.layer.add(basicAnimation2, forKey: "position")
        self.addNextImage(forImageView: firstImageView)
    }
    
    private func getBasicAnimation(withInitialPostion initialPos: CGPoint, finalPos: CGPoint) -> CABasicAnimation {
        let basicAnimation = CABasicAnimation(keyPath: "position")
        basicAnimation.fromValue = NSValue(cgPoint: initialPos)
        basicAnimation.toValue = NSValue(cgPoint: finalPos)
        basicAnimation.duration = 1
        basicAnimation.isRemovedOnCompletion = false
        basicAnimation.fillMode = CAMediaTimingFillMode.forwards
        basicAnimation.timingFunction = CAMediaTimingFunction(name: CAMediaTimingFunctionName.easeInEaseOut)
        return basicAnimation
    }
    
    private func addNextImage(forImageView imageView: UIImageView ) {
        let iconIndex = self.iconsInterval % self.imageArray.count
        let imageId = imageArray[iconIndex]
        setDashImage(forImageId: imageId, onImageView: imageView)
        iconsInterval += 1
    }
    
    private func startBackColorAnimation() {
        var colorIndex = (self.iconsInterval-1) % self.imageArray.count
        var prevIndex = (self.iconsInterval-2) % self.imageArray.count
        if colorIndex > colorArray.count - 1 {
            colorIndex = 0
        }
        if prevIndex > colorArray.count - 1 {
            prevIndex = 0
        }
        let basicAnimation = CABasicAnimation(keyPath: "backgroundColor")
        basicAnimation.fromValue = UIColor(hexString: colorArray[prevIndex])?.cgColor
        basicAnimation.toValue = UIColor(hexString: colorArray[colorIndex])?.cgColor
        basicAnimation.duration = 0.5
        basicAnimation.isRemovedOnCompletion = false
        basicAnimation.fillMode = CAMediaTimingFillMode.forwards
        imageBackgroundView.layer.add(basicAnimation, forKey: "backgroundColor")
    }