FaceViewController

import UIKit

class ViewController: UIViewController {

    //MART: 1. @IBOutlet weak var faceView: FaceView!
    
    //MART: 9.
    /*
     IBOutletweak var faceView: FaceView! {
     didSet {
        updateUI()
        }
     }

    */
    
    @IBOutlet weak var faceView: FaceView! {
        didSet {
            let handler = #selector(FaceView.changeScale(byReactingTo:))
            let pinchRecognizer = UIPinchGestureRecognizer(target: faceView, action: handler)
            faceView.addGestureRecognizer(pinchRecognizer)
            let tapRecognizer = UITapGestureRecognizer(target: self, action: #selector(toggleEyes(byReactingTo:)))
            tapRecognizer.numberOfTapsRequired = 1
            faceView.addGestureRecognizer(tapRecognizer)
            let swipeUpRecogizer = UISwipeGestureRecognizer(target: self, action: #selector(increaseHappiness))
            swipeUpRecogizer.direction = .up
            faceView.addGestureRecognizer(swipeUpRecogizer)
            let swipeDownRecogizer = UISwipeGestureRecognizer(target: self, action: #selector(decreaseHappiness))
            swipeDownRecogizer.direction = .down
            faceView.addGestureRecognizer(swipeDownRecogizer)
            updateUI()
        }
    }
    
    func increaseHappiness()
    {
        expression = expression.happier
    }
    
    func decreaseHappiness()
    {
        expression = expression.sadder
    }
    
    func toggleEyes(byReactingTo tapRecognizer: UIPinchGestureRecognizer) {
        if tapRecognizer.state == .ended {
            let eyes: FacialExpression.Eyes = (expression.eyes == .closed) ? .open : .closed
            expression = FacialExpression(eyes: eyes, mouth: expression.mouth)
        }
    }
    
    //MART: 3.var expression = FacialExpression(eyes:.open, mouth:.grin)
    //MART: 8
    var expression = FacialExpression(eyes:.open, mouth:.grin) {
        didSet {
            updateUI()
        }
    }
    
    //MART: 4.
    //option chain
    private func updateUI() {
        switch expression.eyes {
        case .open:
            faceView.eyesOpen = true
        case .closed:
            faceView.eyesOpen = false
        case .squinting:
            faceView.eyesOpen = false
        }
        //MART: 6.
        //MART: 7. ??
        faceView.mouthCurvature = mouthCurvatures[expression.mouth] ?? 0.0
    }
    
    //MART: 5.
    private let mouthCurvatures = [FacialExpression.Mouth.grin:0.5, .frown:-1.0, .smile:1.0, .neutral: 0.0, .smirk:-0.5]
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        
        //let
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}