/**
 * @license MIT
 * topbar 2.0.0, 2023-02-04
 * https://buunguyen.github.io/topbar
 * Copyright (c) 2021 Buu Nguyen
 */
;(function (window, document) {
  "use strict"

  // https://gist.github.com/paulirish/1579671
  ;(function () {
    var lastTime = 0
    var vendors = ["ms", "moz", "webkit", "o"]
    for (var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
      window.requestAnimationFrame =
        window[vendors[x] + "RequestAnimationFrame"]
      window.cancelAnimationFrame =
        window[vendors[x] + "CancelAnimationFrame"] ||
        window[vendors[x] + "CancelRequestAnimationFrame"]
    }
    if (!window.requestAnimationFrame)
      window.requestAnimationFrame = function (callback, element) {
        var currTime = new Date().getTime()
        var timeToCall = Math.max(0, 16 - (currTime - lastTime))
        var id = window.setTimeout(function () {
          callback(currTime + timeToCall)
        }, timeToCall)
        lastTime = currTime + timeToCall
        return id
      }
    if (!window.cancelAnimationFrame)
      window.cancelAnimationFrame = function (id) {
        clearTimeout(id)
      }
  })()

  var canvas,
    currentProgress,
    showing,
    progressTimerId = null,
    fadeTimerId = null,
    delayTimerId = null,
    addEvent = function (elem, type, handler) {
      if (elem.addEventListener) elem.addEventListener(type, handler, false)
      else if (elem.attachEvent) elem.attachEvent("on" + type, handler)
      else elem["on" + type] = handler
    },
    options = {
      autoRun: true,
      barThickness: 3,
      barColors: {
        0: "rgba(26,  188, 156, .9)",
        ".25": "rgba(52,  152, 219, .9)",
        ".50": "rgba(241, 196, 15,  .9)",
        ".75": "rgba(230, 126, 34,  .9)",
        "1.0": "rgba(211, 84,  0,   .9)",
      },
      shadowBlur: 10,
      shadowColor: "rgba(0,   0,   0,   .6)",
      className: null,
    },
    repaint = function () {
      canvas.width = window.innerWidth
      canvas.height = options.barThickness * 5 // need space for shadow

      var ctx = canvas.getContext("2d")
      ctx.shadowBlur = options.shadowBlur
      ctx.shadowColor = options.shadowColor

      var lineGradient = ctx.createLinearGradient(0, 0, canvas.width, 0)
      for (var stop in options.barColors)
        lineGradient.addColorStop(stop, options.barColors[stop])
      ctx.lineWidth = options.barThickness
      ctx.beginPath()
      ctx.moveTo(0, options.barThickness / 2)
      ctx.lineTo(
        Math.ceil(currentProgress * canvas.width),
        options.barThickness / 2
      )
      ctx.strokeStyle = lineGradient
      ctx.stroke()
    },
    createCanvas = function () {
      canvas = document.createElement("canvas")
      var style = canvas.style
      style.position = "fixed"
      style.top = style.left = style.right = style.margin = style.padding = 0
      style.zIndex = 100001
      style.display = "none"
      if (options.className) canvas.classList.add(options.className)
      document.body.appendChild(canvas)
      addEvent(window, "resize", repaint)
    },
    topbar = {
      config: function (opts) {
        for (var key in opts)
          if (options.hasOwnProperty(key)) options[key] = opts[key]
      },
      show: function (delay) {
        if (showing) return
        if (delay) {
          if (delayTimerId) return
          delayTimerId = setTimeout(() => topbar.show(), delay)
        } else {
          showing = true
          if (fadeTimerId !== null) window.cancelAnimationFrame(fadeTimerId)
          if (!canvas) createCanvas()
          canvas.style.opacity = 1
          canvas.style.display = "block"
          topbar.progress(0)
          if (options.autoRun) {
            ;(function loop() {
              progressTimerId = window.requestAnimationFrame(loop)
              topbar.progress(
                "+" + 0.05 * Math.pow(1 - Math.sqrt(currentProgress), 2)
              )
            })()
          }
        }
      },
      progress: function (to) {
        if (typeof to === "undefined") return currentProgress
        if (typeof to === "string") {
          to =
            (to.indexOf("+") >= 0 || to.indexOf("-") >= 0
              ? currentProgress
              : 0) + parseFloat(to)
        }
        currentProgress = to > 1 ? 1 : to
        repaint()
        return currentProgress
      },
      hide: function () {
        clearTimeout(delayTimerId)
        delayTimerId = null
        if (!showing) return
        showing = false
        if (progressTimerId != null) {
          window.cancelAnimationFrame(progressTimerId)
          progressTimerId = null
        }
        ;(function loop() {
          if (topbar.progress("+.1") >= 1) {
            canvas.style.opacity -= 0.05
            if (canvas.style.opacity <= 0.05) {
              canvas.style.display = "none"
              fadeTimerId = null
              return
            }
          }
          fadeTimerId = window.requestAnimationFrame(loop)
        })()
      },
    }

  if (typeof module === "object" && typeof module.exports === "object") {
    module.exports = topbar
  } else if (typeof define === "function" && define.amd) {
    define(function () {
      return topbar
    })
  } else {
    this.topbar = topbar
  }
}).call(this, window, document)