class Circle {
    constructor({ origin, speed, color, angle, context }) {
      this.origin = origin
      this.position = { ...this.origin }
      this.color = color
      this.speed = speed
      this.angle = angle
      this.context = context
      this.renderCount = 0
    }
  
    draw() {
      this.context.fillStyle = this.color
      this.context.beginPath()
      this.context.arc(this.position.x, this.position.y, 2, 0, Math.PI * 2)
      this.context.fill()
    }
  
    move() {
      this.position.x = (Math.sin(this.angle) * this.speed) + this.position.x
      this.position.y = (Math.cos(this.angle) * this.speed) + this.position.y + (this.renderCount * 0.3)
      this.renderCount++
    }
  }
  
  class Boom {
    constructor ({ origin, context, circleCount = 10, area }) {
      this.origin = origin
      this.context = context
      this.circleCount = circleCount
      this.area = area
      this.stop = false
      this.circles = []
    }
  
    randomArray(range) {
      const length = range.length
      const randomIndex = Math.floor(length * Math.random())
      return range[randomIndex]
    }
  
    randomColor() {
      const range = ['8', '9', 'A', 'B', 'C', 'D', 'E', 'F']
      return '#' + this.randomArray(range) + this.randomArray(range) + this.randomArray(range) + this.randomArray(range) + this.randomArray(range) + this.randomArray(range)
    }
  
    randomRange(start, end) {
      return (end - start) * Math.random() + start
    }
  
    init() {
      for(let i = 0; i < this.circleCount; i++) {
        const circle = new Circle({
          context: this.context,
          origin: this.origin,
          color: this.randomColor(),
          angle: this.randomRange(Math.PI - 1, Math.PI + 1),
          speed: this.randomRange(1, 6)
        })
        this.circles.push(circle)
      }
    }
  
    move() {
      this.circles.forEach((circle, index) => {
        if (circle.position.x > this.area.width || circle.position.y > this.area.height) {
          return this.circles.splice(index, 1)
        }
        circle.move()
      })
      if (this.circles.length == 0) {
        this.stop = true
      }
    }
  
    draw() {
      this.circles.forEach(circle => circle.draw())
    }
  }
  
  class CursorSpecialEffects {
    constructor() {
      this.computerCanvas = document.createElement('canvas')
      this.renderCanvas = document.createElement('canvas')
  
      this.computerContext = this.computerCanvas.getContext('2d')
      this.renderContext = this.renderCanvas.getContext('2d')
  
      this.globalWidth = window.innerWidth
      this.globalHeight = window.innerHeight
  
      this.booms = []
      this.running = false
    }
  
    handleMouseDown(e) {
      const boom = new Boom({
        origin: { x: e.clientX, y: e.clientY },
        context: this.computerContext,
        area: {
          width: this.globalWidth,
          height: this.globalHeight
        }
      })
      boom.init()
      this.booms.push(boom)
      this.running || this.run()
    }
  
    handlePageHide() {
      this.booms = []
      this.running = false
    }
  
    init() {
      const style = this.renderCanvas.style
      style.position = 'fixed'
      style.top = style.left = 0
      style.zIndex = '999999999999999999999999999999999999999999'
      style.pointerEvents = 'none'
  
      style.width = this.renderCanvas.width = this.computerCanvas.width = this.globalWidth
      style.height = this.renderCanvas.height = this.computerCanvas.height = this.globalHeight
  
      document.body.append(this.renderCanvas)
  
      window.addEventListener('mousedown', this.handleMouseDown.bind(this))
      window.addEventListener('pagehide', this.handlePageHide.bind(this))
    }
  
    run() {
      this.running = true
      if (this.booms.length == 0) {
        return this.running = false
      }
  
      requestAnimationFrame(this.run.bind(this))
  
      this.computerContext.clearRect(0, 0, this.globalWidth, this.globalHeight)
      this.renderContext.clearRect(0, 0, this.globalWidth, this.globalHeight)
  
      this.booms.forEach((boom, index) => {
        if (boom.stop) {
          return this.booms.splice(index, 1)
        }
        boom.move()
        boom.draw()
      })
      this.renderContext.drawImage(this.computerCanvas, 0, 0, this.globalWidth, this.globalHeight)
    }
  }
  
  const cursorSpecialEffects = new CursorSpecialEffects()
  cursorSpecialEffects.init()