text: import $ from 'jquery'
  import Util from './util'
  
  /**
   * --------------------------------------------------------------------------
   * Bootstrap (v4.1.3): scrollspy.js
   * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
   * --------------------------------------------------------------------------
   */
  
  const ScrollSpy = (($) => {
    /**
     * ------------------------------------------------------------------------
     * Constants
     * ------------------------------------------------------------------------
     */
  
    const NAME               = 'scrollspy'
    const VERSION            = '4.1.3'
    const DATA_KEY           = 'bs.scrollspy'
    const EVENT_KEY          = `.${DATA_KEY}`
    const DATA_API_KEY       = '.data-api'
    const JQUERY_NO_CONFLICT = $.fn[NAME]
  
    const Default = {
      offset : 10,
      method : 'auto',
      target : ''
    }
  
    const DefaultType = {
      offset : 'number',
      method : 'string',
      target : '(string|element)'
    }
  
    const Event = {
      ACTIVATE      : `activate${EVENT_KEY}`,
      SCROLL        : `scroll${EVENT_KEY}`,
      LOAD_DATA_API : `load${EVENT_KEY}${DATA_API_KEY}`
    }
  
    const ClassName = {
      DROPDOWN_ITEM : 'dropdown-item',
      DROPDOWN_MENU : 'dropdown-menu',
      ACTIVE        : 'active'
    }
  
    const Selector = {
      DATA_SPY        : '[data-spy="scroll"]',
      ACTIVE          : '.active',
      NAV_LIST_GROUP  : '.nav, .list-group',
      NAV_LINKS       : '.nav-link',
      NAV_ITEMS       : '.nav-item',
      LIST_ITEMS      : '.list-group-item',
      DROPDOWN        : '.dropdown',
      DROPDOWN_ITEMS  : '.dropdown-item',
      DROPDOWN_TOGGLE : '.dropdown-toggle'
    }
  
    const OffsetMethod = {
      OFFSET   : 'offset',
      POSITION : 'position'
    }
  
    /**
     * ------------------------------------------------------------------------
     * Class Definition
     * ------------------------------------------------------------------------
     */
  
    class ScrollSpy {
      constructor(element, config) {
        this._element       = element
        this._scrollElement = element.tagName === 'BODY' ? window : element
        this._config        = this._getConfig(config)
        this._selector      = `${this._config.target} ${Selector.NAV_LINKS},` +
                              `${this._config.target} ${Selector.LIST_ITEMS},` +
                              `${this._config.target} ${Selector.DROPDOWN_ITEMS}`
        this._offsets       = []
        this._targets       = []
        this._activeTarget  = null
        this._scrollHeight  = 0
  
        $(this._scrollElement).on(Event.SCROLL, (event) => this._process(event))
  
        this.refresh()
        this._process()
      }
  
      // Getters
  
      static get VERSION() {
        return VERSION
      }
  
      static get Default() {
        return Default
      }
  
      // Public
  
      refresh() {
        const autoMethod = this._scrollElement === this._scrollElement.window
          ? OffsetMethod.OFFSET : OffsetMethod.POSITION
  
        const offsetMethod = this._config.method === 'auto'
          ? autoMethod : this._config.method
  
        const offsetBase = offsetMethod === OffsetMethod.POSITION
          ? this._getScrollTop() : 0
  
        this._offsets = []
        this._targets = []
  
        this._scrollHeight = this._getScrollHeight()
  
        const targets = [].slice.call(document.querySelectorAll(this._selector))
  
        targets
          .map((element) => {
            let target
            const targetSelector = Util.getSelectorFromElement(element)
  
            if (targetSelector) {
              target = document.querySelector(targetSelector)
            }
  
            if (target) {
              const targetBCR = target.getBoundingClientRect()
              if (targetBCR.width || targetBCR.height) {
                // TODO (fat): remove sketch reliance on jQuery position/offset
                return [
                  $(target)[offsetMethod]().top + offsetBase,
                  targetSelector
                ]
              }
            }
            return null
          })
          .filter((item) => item)
          .sort((a, b) => a[0] - b[0])
          .forEach((item) => {
            this._offsets.push(item[0])
            this._targets.push(item[1])
          })
      }
  
      dispose() {
        $.removeData(this._element, DATA_KEY)
        $(this._scrollElement).off(EVENT_KEY)
  
        this._element       = null
        this._scrollElement = null
        this._config        = null
        this._selector      = null
        this._offsets       = null
        this._targets       = null
        this._activeTarget  = null
        this._scrollHeight  = null
      }
  
      // Private
  
      _getConfig(config) {
        config = {
          ...Default,
          ...typeof config === 'object' && config ? config : {}
        }
  
        if (typeof config.target !== 'string') {
          let id = $(config.target).attr('id')
          if (!id) {
            id = Util.getUID(NAME)
            $(config.target).attr('id', id)
          }
          config.target = `#${id}`
        }
  
        Util.typeCheckConfig(NAME, config, DefaultType)
  
        return config
      }
  
      _getScrollTop() {
        return this._scrollElement === window
          ? this._scrollElement.pageYOffset : this._scrollElement.scrollTop
      }
  
      _getScrollHeight() {
        return this._scrollElement.scrollHeight || Math.max(
          document.body.scrollHeight,
          document.documentElement.scrollHeight
        )
      }
  
      _getOffsetHeight() {
        return this._scrollElement === window
          ? window.innerHeight : this._scrollElement.getBoundingClientRect().height
      }
  
      _process() {
        const scrollTop    = this._getScrollTop() + this._config.offset
        const scrollHeight = this._getScrollHeight()
        const maxScroll    = this._config.offset +
          scrollHeight -
          this._getOffsetHeight()
  
        if (this._scrollHeight !== scrollHeight) {
          this.refresh()
        }
  
        if (scrollTop >= maxScroll) {
          const target = this._targets[this._targets.length - 1]
  
          if (this._activeTarget !== target) {
            this._activate(target)
          }
          return
        }
  
        if (this._activeTarget && scrollTop < this._offsets[0] && this._offsets[0] > 0) {
          this._activeTarget = null
          this._clear()
          return
        }
  
        const offsetLength = this._offsets.length
        for (let i = offsetLength; i--;) {
          const isActiveTarget = this._activeTarget !== this._targets[i] &&
              scrollTop >= this._offsets[i] &&
              (typeof this._offsets[i + 1] === 'undefined' ||
                  scrollTop < this._offsets[i + 1])
  
          if (isActiveTarget) {
            this._activate(this._targets[i])
          }
        }
      }
  
      _activate(target) {
        this._activeTarget = target
  
        this._clear()
  
        let queries = this._selector.split(',')
        // eslint-disable-next-line arrow-body-style
        queries = queries.map((selector) => {
          return `${selector}[data-target="${target}"],` +
                 `${selector}[href="${target}"]`
        })
  
        const $link = $([].slice.call(document.querySelectorAll(queries.join(','))))
  
        if ($link.hasClass(ClassName.DROPDOWN_ITEM)) {
          $link.closest(Selector.DROPDOWN).find(Selector.DROPDOWN_TOGGLE).addClass(ClassName.ACTIVE)
          $link.addClass(ClassName.ACTIVE)
        } else {
          // Set triggered link as active
          $link.addClass(ClassName.ACTIVE)
          // Set triggered links parents as active
          // With both <ul> and <nav> markup a parent is the previous sibling of any nav ancestor
          $link.parents(Selector.NAV_LIST_GROUP).prev(`${Selector.NAV_LINKS}, ${Selector.LIST_ITEMS}`).addClass(ClassName.ACTIVE)
          // Handle special case when .nav-link is inside .nav-item
          $link.parents(Selector.NAV_LIST_GROUP).prev(Selector.NAV_ITEMS).children(Selector.NAV_LINKS).addClass(ClassName.ACTIVE)
        }
  
        $(this._scrollElement).trigger(Event.ACTIVATE, {
          relatedTarget: target
        })
      }
  
      _clear() {
        const nodes = [].slice.call(document.querySelectorAll(this._selector))
        $(nodes).filter(Selector.ACTIVE).removeClass(ClassName.ACTIVE)
      }
  
      // Static
  
      static _jQueryInterface(config) {
        return this.each(function () {
          let data = $(this).data(DATA_KEY)
          const _config = typeof config === 'object' && config
  
          if (!data) {
            data = new ScrollSpy(this, _config)
            $(this).data(DATA_KEY, data)
          }
  
          if (typeof config === 'string') {
            if (typeof data[config] === 'undefined') {
              throw new TypeError(`No method named "${config}"`)
            }
            data[config]()
          }
        })
      }
    }
  
    /**
     * ------------------------------------------------------------------------
     * Data Api implementation
     * ------------------------------------------------------------------------
     */
  
    $(window).on(Event.LOAD_DATA_API, () => {
      const scrollSpys = [].slice.call(document.querySelectorAll(Selector.DATA_SPY))
  
      const scrollSpysLength = scrollSpys.length
      for (let i = scrollSpysLength; i--;) {
        const $spy = $(scrollSpys[i])
        ScrollSpy._jQueryInterface.call($spy, $spy.data())
      }
    })
  
    /**
     * ------------------------------------------------------------------------
     * jQuery
     * ------------------------------------------------------------------------
     */
  
    $.fn[NAME] = ScrollSpy._jQueryInterface
    $.fn[NAME].Constructor = ScrollSpy
    $.fn[NAME].noConflict = function () {
      $.fn[NAME] = JQUERY_NO_CONFLICT
      return ScrollSpy._jQueryInterface
    }
  
    return ScrollSpy
  })($)
  
  export default ScrollSpy
  