/**
 * d3.tip
 * Copyright (c) 2013-2017 Justin Palmer
 *
 * Tooltips for d3.js SVG visualizations
 */
// eslint-disable-next-line no-extra-semi
import { map } from 'd3-collection'
import { selection, select } from 'd3-selection'
// Public - constructs a new tooltip
//
// Returns a tip
export default function() {
  var direction   = d3TipDirection,
      offset      = d3TipOffset,
      html        = d3TipHTML,
      rootElement = document.body,
      node        = initNode(),
      svg         = null,
      point       = null,
      target      = null

  function tip(vis) {
    svg = getSVGNode(vis)
    if (!svg) return
    point = svg.createSVGPoint()
    rootElement.appendChild(node)
  }

  // Public - show the tooltip on the screen
  //
  // Returns a tip
  tip.show = function() {
    var args = Array.prototype.slice.call(arguments)
    if (args[args.length - 1] instanceof SVGElement) target = args.pop()

    var content = html.apply(this, args),
        poffset = offset.apply(this, args),
        dir     = direction.apply(this, args),
        nodel   = getNodeEl(),
        i       = directions.length,
        coords,
        scrollTop  = document.documentElement.scrollTop ||
      rootElement.scrollTop,
        scrollLeft = document.documentElement.scrollLeft ||
      rootElement.scrollLeft

    nodel.html(content)
      .style('opacity', 1).style('pointer-events', 'all')

    while (i--) nodel.classed(directions[i], false)
    coords = directionCallbacks.get(dir).apply(this)
    nodel.classed(dir, true)
      .style('top', (coords.top + poffset[0]) + scrollTop + 'px')
      .style('left', (coords.left + poffset[1]) + scrollLeft + 'px')

    return tip
  }

  // Public - hide the tooltip
  //
  // Returns a tip
  tip.hide = function() {
    var nodel = getNodeEl()
    nodel.style('opacity', 0).style('pointer-events', 'none')
    return tip
  }

  // Public: Proxy attr calls to the d3 tip container.
  // Sets or gets attribute value.
  //
  // n - name of the attribute
  // v - value of the attribute
  //
  // Returns tip or attribute value
  // eslint-disable-next-line no-unused-vars
  tip.attr = function(n, v) {
    if (arguments.length < 2 && typeof n === 'string') {
      return getNodeEl().attr(n)
    }

    var args =  Array.prototype.slice.call(arguments)
    selection.prototype.attr.apply(getNodeEl(), args)
    return tip
  }

  // Public: Proxy style calls to the d3 tip container.
  // Sets or gets a style value.
  //
  // n - name of the property
  // v - value of the property
  //
  // Returns tip or style property value
  // eslint-disable-next-line no-unused-vars
  tip.style = function(n, v) {
    if (arguments.length < 2 && typeof n === 'string') {
      return getNodeEl().style(n)
    }

    var args = Array.prototype.slice.call(arguments)
    selection.prototype.style.apply(getNodeEl(), args)
    return tip
  }

  // Public: Set or get the direction of the tooltip
  //
  // v - One of n(north), s(south), e(east), or w(west), nw(northwest),
  //     sw(southwest), ne(northeast) or se(southeast)
  //
  // Returns tip or direction
  tip.direction = function(v) {
    if (!arguments.length) return direction
    direction = v == null ? v : functor(v)

    return tip
  }

  // Public: Sets or gets the offset of the tip
  //
  // v - Array of [x, y] offset
  //
  // Returns offset or
  tip.offset = function(v) {
    if (!arguments.length) return offset
    offset = v == null ? v : functor(v)

    return tip
  }

  // Public: sets or gets the html value of the tooltip
  //
  // v - String value of the tip
  //
  // Returns html value or tip
  tip.html = function(v) {
    if (!arguments.length) return html
    html = v == null ? v : functor(v)

    return tip
  }

  // Public: sets or gets the root element anchor of the tooltip
  //
  // v - root element of the tooltip
  //
  // Returns root node of tip
  tip.rootElement = function(v) {
    if (!arguments.length) return rootElement
    rootElement = v == null ? v : functor(v)

    return tip
  }

  // Public: destroys the tooltip and removes it from the DOM
  //
  // Returns a tip
  tip.destroy = function() {
    if (node) {
      getNodeEl().remove()
      node = null
    }
    return tip
  }

  function d3TipDirection() { return 'n' }
  function d3TipOffset() { return [0, 0] }
  function d3TipHTML() { return ' ' }

  var directionCallbacks = map({
        n:  directionNorth,
        s:  directionSouth,
        e:  directionEast,
        w:  directionWest,
        nw: directionNorthWest,
        ne: directionNorthEast,
        sw: directionSouthWest,
        se: directionSouthEast
      }),
      directions = directionCallbacks.keys()

  function directionNorth() {
    var bbox = getScreenBBox(this)
    return {
      top:  bbox.n.y - node.offsetHeight,
      left: bbox.n.x - node.offsetWidth / 2
    }
  }

  function directionSouth() {
    var bbox = getScreenBBox(this)
    return {
      top:  bbox.s.y,
      left: bbox.s.x - node.offsetWidth / 2
    }
  }

  function directionEast() {
    var bbox = getScreenBBox(this)
    return {
      top:  bbox.e.y - node.offsetHeight / 2,
      left: bbox.e.x
    }
  }

  function directionWest() {
    var bbox = getScreenBBox(this)
    return {
      top:  bbox.w.y - node.offsetHeight / 2,
      left: bbox.w.x - node.offsetWidth
    }
  }

  function directionNorthWest() {
    var bbox = getScreenBBox(this)
    return {
      top:  bbox.nw.y - node.offsetHeight,
      left: bbox.nw.x - node.offsetWidth
    }
  }

  function directionNorthEast() {
    var bbox = getScreenBBox(this)
    return {
      top:  bbox.ne.y - node.offsetHeight,
      left: bbox.ne.x
    }
  }

  function directionSouthWest() {
    var bbox = getScreenBBox(this)
    return {
      top:  bbox.sw.y,
      left: bbox.sw.x - node.offsetWidth
    }
  }

  function directionSouthEast() {
    var bbox = getScreenBBox(this)
    return {
      top:  bbox.se.y,
      left: bbox.se.x
    }
  }

  function initNode() {
    var div = select(document.createElement('div'))
    div
      .style('position', 'absolute')
      .style('top', 0)
      .style('opacity', 0)
      .style('pointer-events', 'none')
      .style('box-sizing', 'border-box')

    return div.node()
  }

  function getSVGNode(element) {
    var svgNode = element.node()
    if (!svgNode) return null
    if (svgNode.tagName.toLowerCase() === 'svg') return svgNode
    return svgNode.ownerSVGElement
  }

  function getNodeEl() {
    if (node == null) {
      node = initNode()
      // re-add node to DOM
      rootElement.appendChild(node)
    }
    return select(node)
  }

  // Private - gets the screen coordinates of a shape
  //
  // Given a shape on the screen, will return an SVGPoint for the directions
  // n(north), s(south), e(east), w(west), ne(northeast), se(southeast),
  // nw(northwest), sw(southwest).
  //
  //    +-+-+
  //    |   |
  //    +   +
  //    |   |
  //    +-+-+
  //
  // Returns an Object {n, s, e, w, nw, sw, ne, se}
  function getScreenBBox(targetShape) {
    var targetel   = target || targetShape

    while (targetel.getScreenCTM == null && targetel.parentNode != null) {
      targetel = targetel.parentNode
    }

    var bbox       = {},
        matrix     = targetel.getScreenCTM(),
        tbbox      = targetel.getBBox(),
        width      = tbbox.width,
        height     = tbbox.height,
        x          = tbbox.x,
        y          = tbbox.y

    point.x = x
    point.y = y
    bbox.nw = point.matrixTransform(matrix)
    point.x += width
    bbox.ne = point.matrixTransform(matrix)
    point.y += height
    bbox.se = point.matrixTransform(matrix)
    point.x -= width
    bbox.sw = point.matrixTransform(matrix)
    point.y -= height / 2
    bbox.w = point.matrixTransform(matrix)
    point.x += width
    bbox.e = point.matrixTransform(matrix)
    point.x -= width / 2
    point.y -= height / 2
    bbox.n = point.matrixTransform(matrix)
    point.y += height
    bbox.s = point.matrixTransform(matrix)

    return bbox
  }

  // Private - replace D3JS 3.X d3.functor() function
  function functor(v) {
    return typeof v === 'function' ? v : function() {
      return v
    }
  }

  return tip
}