//
//  DemoViewController.swift
//  Text Art
//
//  Created by Bitmatrix110 on 19/07/19.
//  Copyright © 2019 vasundhara. All rights reserved.
//

import UIKit



class CourseCell: UICollectionViewCell {

    @IBOutlet weak var lbl: UILabel!
}

class DemoViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource {

    @IBOutlet weak var col: UICollectionView!

    @IBOutlet weak var viewMain: UIView!

    var pulsatingLayer = CAShapeLayer()

    let colorPulse = UIColor.init(red: 200.0/255.0, green: 200.0/255.0, blue: 200.0/255.0, alpha: 0.5)

    var timerCount: Timer!

    var counter: Int = 0
    var currentIndex: Int = 0

    override func viewDidLoad() {
        super.viewDidLoad()

        viewMain.layer.cornerRadius = 50.0

        let circularPath = UIBezierPath.init(arcCenter: .zero, radius: 50, startAngle: 0, endAngle: 2*CGFloat.pi, clockwise: true)

        pulsatingLayer = createCircleShapeLayer(radius: 50.0, inView: viewMain)
        viewMain.layer.addSublayer(pulsatingLayer)

        animatePulsatingLayer()


        let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
        layout.itemSize = CGSize(width: UIScreen.main.bounds.width, height: UIScreen.main.bounds.height-139.0)
        layout.scrollDirection = .horizontal
        col.collectionViewLayout = layout

        self.col.reloadData()

        DispatchQueue.main.asyncAfter(deadline: .now()+0.2) {
            self.timerCount = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(self.timerFired), userInfo: nil, repeats: true)
        }
    }

    func createCircleShapeLayer(radius: CGFloat, inView: UIView) -> CAShapeLayer
    {
        let circularPath = UIBezierPath.init(arcCenter: .zero, radius: radius, startAngle: 0, endAngle: 2*CGFloat.pi, clockwise: true)

        let pulsatingLayer = CAShapeLayer()
        pulsatingLayer.path = circularPath.cgPath
        pulsatingLayer.strokeColor = colorPulse.cgColor
        pulsatingLayer.lineWidth = 0
        pulsatingLayer.fillColor = colorPulse.cgColor
        pulsatingLayer.lineCap = CAShapeLayerLineCap.round
        pulsatingLayer.position = CGPoint.init(x: inView.frame.height/2.0, y: inView.frame.height/2.0)

        return pulsatingLayer
    }

    func animatePulsatingLayer()
    {
        let animation = CABasicAnimation.init(keyPath: "transform.scale")
        animation.toValue = 1.4
        animation.duration = 0.5
        animation.timingFunction = CAMediaTimingFunction.init(name: CAMediaTimingFunctionName.easeOut)
        animation.autoreverses = true
        animation.repeatCount = 2 //Float.infinity

        pulsatingLayer.add(animation, forKey: "pulsing")
    }

    @objc func timerFired()
    {
        counter += 1

        if counter == 2
        {
            counter = 0

            if currentIndex > 8
            {
                currentIndex = -1
            }

            let indexPath = IndexPath.init(item: currentIndex+1, section: 0)
            col.scrollToItem(at: indexPath, at: .right, animated: true)
        }
    }

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 10
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CourseCell", for: indexPath) as! CourseCell
        cell.lbl.text = "\(indexPath.item)"
        return cell
    }

    func scrollViewDidScroll(_ scrollView: UIScrollView) {

        let offsetX = col.contentOffset.x
        let quotient = Int(offsetX / UIScreen.main.bounds.width)
        let reminder = offsetX.truncatingRemainder(dividingBy: UIScreen.main.bounds.width)


        if reminder > (UIScreen.main.bounds.width/2.0)
        {
            if self.currentIndex != quotient+1
            {
                self.currentIndex = quotient+1

                print("index : \(quotient+1)")
            }
        }
        else
        {
            if self.currentIndex != quotient
            {
                self.currentIndex = quotient

                print("index : \(quotient)")
            }
        }

    }
}