console.clear()

class Utils {
  static randomRange(min, max) {
    return Math.random() * (max - min) + min
  }

  static mapRange (value, inputMin, inputMax, outputMin, outputMax, clamp) {
    if (Math.abs(inputMin - inputMax) < Number.EPSILON) {
      return outputMin;
    } else {
      var outVal = ((value - inputMin) / (inputMax - inputMin) * (outputMax - outputMin) + outputMin);
      if (clamp) {
        if (outputMax < outputMin) {
          if (outVal < outputMax) outVal = outputMax;
          else if (outVal > outputMin) outVal = outputMin;
        } else {
          if (outVal > outputMax) outVal = outputMax;
          else if (outVal < outputMin) outVal = outputMin;
        }
      }
      return outVal;
    }
  }
}

Utils.simplex = new SimplexNoise('seed') 

class App {
  constructor() {
    this.canvas = document.getElementById('c')
    this.ctx = this.canvas.getContext('2d')
    
    this.shadowCanvas = document.createElement('canvas')
    this.shadowCtx = this.shadowCanvas.getContext('2d')
    
    this.timestamp = 0
    this.fpsHistory = []
    this.angle = 0
    
    this.setUpVars()
    this.setUpListeners()
    // this.setUpGui()
    this.update()
  }

  setUpGui() {
    const pane = new Tweakpane()
    const folder = pane.addFolder({
      expanded: false,
      title: 'Settings',
    })
    folder.addInput(this.config, 'bgColor')
  }
  
  setUpVars() {
    this.canvas.width = this.shadowCanvas.width = this.wWidth = window.innerWidth
    this.canvas.height = this.shadowCanvas.height = this.wHeight = window.innerHeight
    this.wCenterX = this.wWidth / 2
    this.wCenterY = this.wHeight / 2
    this.wHypot = Math.hypot(this.wWidth, this.wHeight)
    this.wMin = Math.min(this.wWidth, this.wHeight)
  }
  
  setUpListeners() {
    window.addEventListener('resize', this.setUpVars.bind(this))
  }

  drawTheThing(ctx, angle, scale = 1, color = '#000') {
    const angleStep = Math.PI * 0.01
    const maxRadius = this.wMin * 0.3 * scale
    let radius = maxRadius
    
    ctx.save()
    ctx.translate(this.wCenterX, this.wCenterY)
    ctx.rotate(this.angle + angle)
    ctx.beginPath()
    
    const startR = Utils.simplex.noise2D(Math.sin(0), this.timestamp) * radius
    const startX = Math.sin(0) * startR
    const startY = Math.cos(0) * startR
    
    ctx.moveTo(startX, startY)
    for (let angle = 0; angle <= Math.PI * 2; angle += angleStep) {
      const n = Utils.simplex.noise2D(Math.sin(angle), this.timestamp)
      const newRadius = n * radius
      const xPos = Math.sin(angle) * newRadius
      const yPos = Math.cos(angle) * newRadius
      
      ctx.lineTo(
        xPos, 
        yPos
      )
    }
    ctx.fillStyle = color
    ctx.fill()
    
    for (let angle = 0; angle <= Math.PI * 2; angle += angleStep) {
      const n = Utils.simplex.noise2D(Math.sin(angle), this.timestamp)
      const newRadius = Math.pow(n * radius, 1.1)
      const xPos = Math.sin(angle) * newRadius
      const yPos = Math.cos(angle) * newRadius
      
      ctx.beginPath()
      ctx.arc(
        xPos, 
        yPos,
        this.wMin * 0.01,
        0, Math.PI * 2
      )
      ctx.fill()
    }
    ctx.restore()
  }
  
  draw(ctx) {
    ctx.save()
    ctx.clearRect(0, 0, this.wWidth, this.wHeight)
    ctx.restore()
    
    this.drawTheThing(ctx, 0)
    this.drawTheThing(ctx, Math.PI * 0.13, 0.9)
    this.drawTheThing(ctx, Math.PI * 0.24, 0.8)
    this.drawTheThing(ctx, Math.PI * 0.37, 0.8)
    this.drawTheThing(ctx, Math.PI * 0.6, 0.8)
    this.drawTheThing(ctx, Math.PI * 0.77, 1)
  }
  
  update(t) {
    const prevTimestamp = this.timestamp * 5000
    
    if (t) {
      this.timestamp = t / 5000
      this.angle += 0.001
      this.draw(this.shadowCtx)
    }
    
    this.ctx.clearRect(0, 0, this.wWidth, this.wHeight)
    this.ctx.drawImage(this.shadowCanvas, 0, 0)
    
    // show fps
    const fps = Math.round(1 / (t - prevTimestamp) * 1000)
    this.fpsHistory.unshift(fps)
    this.fpsHistory.length = 5
    this.ctx.font = '16px sans-serif'
    this.ctx.fillText(this.fpsHistory.reduce((a,b) => a+b) / 5, 50, 50)
    
    window.requestAnimationFrame(this.update.bind(this))
  }
}

new App()