import SpriteKit
import GameplayKit

extension SKPhysicsBody {
func ideal() -> SKPhysicsBody {
  //摩擦係数の値で 1 に近いほど摩擦が多くなります0.0から1.0の間
  self.friction = 0
  self.linearDamping = 0  //粘性//体にかかる流体または空気の摩擦力
  self.angularDamping = 0  //体の回転速度を遅くする特性 0.0から1.0の間の値
  self.restitution = 0.98  //反発率
  self.isDynamic = true  //動かせる性質
  self.allowsRotation = false //角力とインパルスの影響デフォルト値はtrue
  // 重力を無視する　重力の影響を受けない
  //circleA.physicsBody?.affectedByGravity = false
  self.affectedByGravity = true
  return self
}
}

class GameScene: SKScene, SKPhysicsContactDelegate {

  let circleACategory: UInt32 = 0x1 << 0
  let squareACategory: UInt32 = 0x1 << 1
  let squareBCategory: UInt32 = 0x1 << 2
  let bottomCategory:UInt32 = 0x1 << 3
    
  var n = 0
  let label = SKLabelNode(text: "kaisu: 0kai")

override func didMove(to view: SKView) {
  backgroundColor = .blue
  self.physicsWorld.contactDelegate = self
  physicsBody = SKPhysicsBody(edgeLoopFrom: frame)
    physicsWorld.gravity = CGVector(dx: 0, dy: -1.5)
    
  let labelSize: CGFloat = 30.0
  label.fontSize = labelSize
    label.position = CGPoint(x:self.frame.midX, y:self.frame.height/1.12)
  label.fontColor = SKColor.white
  self.addChild(label)

  let circleA = SKShapeNode(circleOfRadius: 40)//circleOfRadiusで円の半径
  circleA.position = CGPoint(x:self.frame.midX, y:self.frame.midY + 140)
  circleA.fillColor = UIColor.red
  circleA.lineWidth = 4.0
  circleA.strokeColor = UIColor.lightGray
  self.addChild(circleA)
  circleA.physicsBody = SKPhysicsBody(circleOfRadius: circleA.frame.width/2).ideal()
    
  let squareA = SKShapeNode(rectOf: CGSize(width:50, height:50),cornerRadius: 3)
  squareA.position = CGPoint(x:self.frame.midX, y:self.frame.midY + 10)
  squareA.fillColor = UIColor.yellow
  squareA.lineWidth = 2.0
  squareA.strokeColor = UIColor.lightGray
  self.addChild(squareA)
  squareA.physicsBody = SKPhysicsBody(rectangleOf: squareA.frame.size).ideal()
  squareA.physicsBody?.affectedByGravity = false
      

  let squareB = SKShapeNode(rectOf: CGSize(width:100, height:100),cornerRadius: 5)
  squareB.position = CGPoint(x:self.frame.midX, y:self.frame.midY - 200)
  squareB.fillColor = .green
  squareB.lineWidth = 0.0
  self.addChild(squareB)
  squareB.physicsBody = SKPhysicsBody(rectangleOf: squareB.frame.size).ideal()
    
  let bottomRect = CGRect(x: self.frame.origin.x, y: self.frame.origin.y, width: self.frame.size.width, height: 1)
  let bottom = SKNode()
  bottom.physicsBody = SKPhysicsBody(edgeLoopFrom: bottomRect)
  self.addChild(bottom)
  //Aカテゴリ
  circleA.physicsBody?.categoryBitMask = circleACategory
  //Bカテゴリ
  squareA.physicsBody?.categoryBitMask = squareACategory
  squareB.physicsBody?.categoryBitMask = squareBCategory
  //bottomカテゴリ
  bottom.physicsBody?.categoryBitMask = bottomCategory
  circleA.physicsBody?.contactTestBitMask = squareACategory | squareBCategory | bottomCategory
}
   //衝突判定処理
 func didBegin(_ contact: SKPhysicsContact) {
     n += 1
     label.text = "kaisu: \(n)kai"
     var firstBody: SKPhysicsBody
     var secondBody: SKPhysicsBody
      if contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask {
       firstBody = contact.bodyA
       secondBody = contact.bodyB
     } else {
       firstBody = contact.bodyB
       secondBody = contact.bodyA
     }

 if firstBody.categoryBitMask == circleACategory && secondBody.categoryBitMask == squareACategory{
   secondBody.node?.removeFromParent()
      }
if firstBody.categoryBitMask == circleACategory && secondBody.categoryBitMask == squareBCategory{
    secondBody.node?.removeFromParent()
  }
 if firstBody.categoryBitMask == circleACategory && secondBody.categoryBitMask == bottomCategory{
     firstBody.node?.removeFromParent()
  }
 }   
 override func touchesBegan(_ touches: Set, with event: UIEvent?) {
}
}