import UIKit
import AVFoundation

class ViewController: UIViewController {

    var bombSoundEffect: AVAudioPlayer?

    var timer = Timer()
    
    // defines a variable called screenSize
    var screenSize:CGRect = UIScreen.main.bounds
    
    // defines variables for the screen height and screen width
    var screenHeight = 0
    var screenWidth = 0
    

	// FINISH ME
    @IBOutlet weak var ship: UIImageView!

	// FINISH ME
    @IBOutlet weak var alien: UIImageView!
    

    // generic func moves the object that you send to the function
    func moveObjectDown(_ object:UIImageView)
    {
    	// FINISH ME
        let x = object.frame.origin.?
        var y = object.frame.origin.?
        let width =  object.frame.size.?
        let height = object.frame.size.?
        
        if Int(y) < screenHeight
        {
            // FINISH ME
            // increase y by 4
       
        }
        else
        {
            y = -height
        }
        
        object.frame = CGRect(x: x, y: y, width: width, height: height)

    }
    


    @IBAction func moveUp(_ sender: UIButton)
    {
        let x = ship.frame.origin.x
        
        // FINISH ME
        var y = ship.frame.origin.?
        
        let width = ship.frame.size.width
        let height = ship.frame.size.height
        
        if y > 24
        {
            // FINISH ME
            // decrease y by 4

        }
        else
        {
        	playSound()
        }
        
        ship.frame = CGRect(x: x, y: y, width: width, height: height)
    }
 
    @IBAction func moveDown(_ sender: UIButton)
    {
    	// FINISH ME
        let x = ship.frame.origin.?
        var y = ship.frame.origin.?
        
        let width = ship.frame.size.?
        let height = ship.frame.size.?
        
        
        
        if y + height + 4 < CGFloat(screenHeight)
        {
            // FINISH ME
            // increase y by 4

        }
        else
        {
        	playSound()
        }
        
        ship.frame = CGRect(x: x, y: y, width: width, height: height)
    }
    

    // FINISH ME
    // handle moving right and left
    
    @IBAction func moveRight(_ sender: UIButton)
    {
    	// FINISH ME
        var x = ship.frame.origin.?
        let y = ship.frame.origin.?
        let width = ship.frame.size.?
        let height = ship.frame.size.?
        if x + width + 4 < CGFloat(screenWidth)
        {
            // FINISH ME
            // increase x by 4

        }
        else
        {
        	playSound()
        }
        
        ship.frame = CGRect(x: x, y: y, width: width, height: height)
        
        // debug info
        print("x=\(x)")
        print("alien width=\(width)")
        print("screenWidth=\(screenWidth)")
    }
    
    @IBAction func moveLeft(_ sender: UIButton)
    {
    	// FINISH ME


    }
    
    
    
    
    
    
    // plays a sound if you call it
    // the sound file must be dragged into the files section
    func playSound()
    {
        // Replace "explosion.mp3" with your sound file
        // Your sound file cannot be more than 2400 kb/second
        let path = Bundle.main.path(forResource: "explosion.mp3", ofType:nil)!
        let url = URL(fileURLWithPath: path)
        
        do {
            bombSoundEffect = try AVAudioPlayer(contentsOf: url)
            bombSoundEffect?.play()
        } catch{
            // couldn't load file :(
        }
    }


 	// FINISH ME
    // Control + Drag your start button here
    @IBAction func startButtonEvent(_ sender: UIButton)
    {
        // shut down the timer
        timer.invalidate()
                
        // start the timer
        // and call timerAction() every 0.1 seconds
        timer = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(timerAction), userInfo: nil, repeats: true)
              
    }

    
   
 	// FINISH ME
    // Control + Drag your stop button here
    @IBAction func stopButtonEvent(_ sender: UIButton)
    {
        // shut down the timer
        timer.invalidate()
    }

    
    // this function gets called over and over again by the timer
    @objc func timerAction()
    {
        moveObjectDown(alien)        
    }
    
   
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        // here we get the width and height of the screen
        screenSize = UIScreen.main.bounds
        screenWidth = Int(screenSize.width)
        screenHeight = Int(screenSize.height)

    }

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


}