text: /**
   * Tools for SVG sanitization
   * @module sanitize
   * @license MIT
   *
   * @copyright 2010 Alexis Deveria, 2010 Jeff Schiller
   */
  
  import {getReverseNS, NS} from './namespaces.js';
  import {isGecko} from './browser.js';
  import {getHref, setHref, getUrlFromAttr} from './utilities.js';
  
  const REVERSE_NS = getReverseNS();
  
  // Todo: Split out into core attributes, presentation attributes, etc. so consistent
  /**
   * This defines which elements and attributes that we support (or at least
   * don't remove)
   * @type {PlainObject}
   */
  const svgWhiteList_ = {
    // SVG Elements
    a: ['class', 'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'id', 'mask', 'opacity', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform', 'xlink:href', 'xlink:title'],
    circle: ['class', 'clip-path', 'clip-rule', 'cx', 'cy', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'id', 'mask', 'opacity', 'r', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform'],
    clipPath: ['class', 'clipPathUnits', 'id'],
    defs: [],
    style: ['type'],
    desc: [],
    ellipse: ['class', 'clip-path', 'clip-rule', 'cx', 'cy', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'id', 'mask', 'opacity', 'requiredFeatures', 'rx', 'ry', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform'],
    feGaussianBlur: ['class', 'color-interpolation-filters', 'id', 'requiredFeatures', 'stdDeviation'],
    feMorphology: ['class', 'in', 'operator', 'radius'],
    filter: ['class', 'color-interpolation-filters', 'filterRes', 'filterUnits', 'height', 'id', 'primitiveUnits', 'requiredFeatures', 'width', 'x', 'xlink:href', 'y'],
    foreignObject: ['class', 'font-size', 'height', 'id', 'opacity', 'requiredFeatures', 'style', 'transform', 'width', 'x', 'y'],
    g: ['class', 'clip-path', 'clip-rule', 'id', 'display', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'mask', 'opacity', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform', 'font-family', 'font-size', 'font-style', 'font-weight', 'text-anchor'],
    image: ['class', 'clip-path', 'clip-rule', 'filter', 'height', 'id', 'mask', 'opacity', 'requiredFeatures', 'style', 'systemLanguage', 'transform', 'width', 'x', 'xlink:href', 'xlink:title', 'y'],
    line: ['class', 'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'id', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'opacity', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform', 'x1', 'x2', 'y1', 'y2'],
    linearGradient: ['class', 'id', 'gradientTransform', 'gradientUnits', 'requiredFeatures', 'spreadMethod', 'systemLanguage', 'x1', 'x2', 'xlink:href', 'y1', 'y2'],
    marker: ['id', 'class', 'markerHeight', 'markerUnits', 'markerWidth', 'orient', 'preserveAspectRatio', 'refX', 'refY', 'systemLanguage', 'viewBox'],
    mask: ['class', 'height', 'id', 'maskContentUnits', 'maskUnits', 'width', 'x', 'y'],
    metadata: ['class', 'id'],
    path: ['class', 'clip-path', 'clip-rule', 'd', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'id', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'opacity', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform'],
    pattern: ['class', 'height', 'id', 'patternContentUnits', 'patternTransform', 'patternUnits', 'requiredFeatures', 'style', 'systemLanguage', 'viewBox', 'width', 'x', 'xlink:href', 'y'],
    polygon: ['class', 'clip-path', 'clip-rule', 'id', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'id', 'class', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'opacity', 'points', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform'],
    polyline: ['class', 'clip-path', 'clip-rule', 'id', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'opacity', 'points', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform'],
    radialGradient: ['class', 'cx', 'cy', 'fx', 'fy', 'gradientTransform', 'gradientUnits', 'id', 'r', 'requiredFeatures', 'spreadMethod', 'systemLanguage', 'xlink:href'],
    rect: ['class', 'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'height', 'id', 'mask', 'opacity', 'requiredFeatures', 'rx', 'ry', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform', 'width', 'x', 'y'],
    stop: ['class', 'id', 'offset', 'requiredFeatures', 'stop-color', 'stop-opacity', 'style', 'systemLanguage'],
    svg: ['class', 'clip-path', 'clip-rule', 'filter', 'id', 'height', 'mask', 'preserveAspectRatio', 'requiredFeatures', 'style', 'systemLanguage', 'viewBox', 'width', 'x', 'xmlns', 'xmlns:se', 'xmlns:xlink', 'y'],
    switch: ['class', 'id', 'requiredFeatures', 'systemLanguage'],
    symbol: ['class', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'font-family', 'font-size', 'font-style', 'font-weight', 'id', 'opacity', 'preserveAspectRatio', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform', 'viewBox'],
    text: ['class', 'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'font-family', 'font-size', 'font-style', 'font-weight', 'id', 'mask', 'opacity', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'text-anchor', 'transform', 'x', 'xml:space', 'y'],
    textPath: ['class', 'id', 'method', 'requiredFeatures', 'spacing', 'startOffset', 'style', 'systemLanguage', 'transform', 'xlink:href'],
    title: [],
    tspan: ['class', 'clip-path', 'clip-rule', 'dx', 'dy', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'font-family', 'font-size', 'font-style', 'font-weight', 'id', 'mask', 'opacity', 'requiredFeatures', 'rotate', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'text-anchor', 'textLength', 'transform', 'x', 'xml:space', 'y'],
    use: ['class', 'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'height', 'id', 'mask', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'transform', 'width', 'x', 'xlink:href', 'y'],
  
    // MathML Elements
    annotation: ['encoding'],
    'annotation-xml': ['encoding'],
    maction: ['actiontype', 'other', 'selection'],
    math: ['class', 'id', 'display', 'xmlns'],
    menclose: ['notation'],
    merror: [],
    mfrac: ['linethickness'],
    mi: ['mathvariant'],
    mmultiscripts: [],
    mn: [],
    mo: ['fence', 'lspace', 'maxsize', 'minsize', 'rspace', 'stretchy'],
    mover: [],
    mpadded: ['lspace', 'width', 'height', 'depth', 'voffset'],
    mphantom: [],
    mprescripts: [],
    mroot: [],
    mrow: ['xlink:href', 'xlink:type', 'xmlns:xlink'],
    mspace: ['depth', 'height', 'width'],
    msqrt: [],
    mstyle: ['displaystyle', 'mathbackground', 'mathcolor', 'mathvariant', 'scriptlevel'],
    msub: [],
    msubsup: [],
    msup: [],
    mtable: ['align', 'columnalign', 'columnlines', 'columnspacing', 'displaystyle', 'equalcolumns', 'equalrows', 'frame', 'rowalign', 'rowlines', 'rowspacing', 'width'],
    mtd: ['columnalign', 'columnspan', 'rowalign', 'rowspan'],
    mtext: [],
    mtr: ['columnalign', 'rowalign'],
    munder: [],
    munderover: [],
    none: [],
    semantics: []
  };
  
  // Produce a Namespace-aware version of svgWhitelist
  const svgWhiteListNS_ = {};
  Object.entries(svgWhiteList_).forEach(function ([elt, atts]) {
    const attNS = {};
    Object.entries(atts).forEach(function ([i, att]) {
      if (att.includes(':')) {
        const v = att.split(':');
        attNS[v[1]] = NS[(v[0]).toUpperCase()];
      } else {
        attNS[att] = att === 'xmlns' ? NS.XMLNS : null;
      }
    });
    svgWhiteListNS_[elt] = attNS;
  });
  
  /**
  * Sanitizes the input node and its children.
  * It only keeps what is allowed from our whitelist defined above.
  * @function module:sanitize.sanitizeSvg
  * @param {Text|Element} node - The DOM element to be checked (we'll also check its children) or text node to be cleaned up
  * @returns {void}
  */
  export const sanitizeSvg = function (node) {
    // Cleanup text nodes
    if (node.nodeType === 3) { // 3 === TEXT_NODE
      // Trim whitespace
      node.nodeValue = node.nodeValue.replace(/^\s+|\s+$/g, '');
      // Remove if empty
      if (!node.nodeValue.length) {
        node.remove();
      }
    }
  
    // We only care about element nodes.
    // Automatically return for all non-element nodes, such as comments, etc.
    if (node.nodeType !== 1) { // 1 == ELEMENT_NODE
      return;
    }
  
    const doc = node.ownerDocument;
    const parent = node.parentNode;
    // can parent ever be null here?  I think the root node's parent is the document...
    if (!doc || !parent) {
      return;
    }
  
    const allowedAttrs = svgWhiteList_[node.nodeName];
    const allowedAttrsNS = svgWhiteListNS_[node.nodeName];
    // if this element is supported, sanitize it
    if (typeof allowedAttrs !== 'undefined') {
      const seAttrs = [];
      let i = node.attributes.length;
      while (i--) {
        // if the attribute is not in our whitelist, then remove it
        // could use jQuery's inArray(), but I don't know if that's any better
        const attr = node.attributes.item(i);
        const attrName = attr.nodeName;
        const attrLocalName = attr.localName;
        const attrNsURI = attr.namespaceURI;
        // Check that an attribute with the correct localName in the correct namespace is on
        // our whitelist or is a namespace declaration for one of our allowed namespaces
        if (!({}.hasOwnProperty.call(allowedAttrsNS, attrLocalName) && attrNsURI === allowedAttrsNS[attrLocalName] && attrNsURI !== NS.XMLNS) &&
          !(attrNsURI === NS.XMLNS && REVERSE_NS[attr.value])) {
          // TODO(codedread): Programmatically add the se: attributes to the NS-aware whitelist.
          // Bypassing the whitelist to allow se: prefixes.
          // Is there a more appropriate way to do this?
          if (attrName.startsWith('se:') || attrName.startsWith('data-')) {
            seAttrs.push([attrName, attr.value]);
          }
          node.removeAttributeNS(attrNsURI, attrLocalName);
        }
  
        // Add spaces before negative signs where necessary
        if (isGecko()) {
          switch (attrName) {
          case 'transform':
          case 'gradientTransform':
          case 'patternTransform': {
            const val = attr.value.replace(/(\d)-/g, '$1 -');
            // const val = attr.value.replace(/(?<digit>\d)-/g, '$<digit> -');
            node.setAttribute(attrName, val);
            break;
          }
          }
        }
  
        // For the style attribute, rewrite it in terms of XML presentational attributes
        if (attrName === 'style') {
          const props = attr.value.split(';');
          let p = props.length;
          while (p--) {
            const [name, val] = props[p].split(':');
            const styleAttrName = (name || '').trim();
            const styleAttrVal = (val || '').trim();
            // Now check that this attribute is supported
            if (allowedAttrs.includes(styleAttrName)) {
              node.setAttribute(styleAttrName, styleAttrVal);
            }
          }
          node.removeAttribute('style');
        }
      }
  
      Object.values(seAttrs).forEach(([att, val]) => {
        node.setAttributeNS(NS.SE, att, val);
      });
  
      // for some elements that have a xlink:href, ensure the URI refers to a local element
      // (but not for links)
      const href = getHref(node);
      if (href &&
        ['filter', 'linearGradient', 'pattern',
          'radialGradient', 'textPath', 'use'].includes(node.nodeName)) {
        // TODO: we simply check if the first character is a #, is this bullet-proof?
        if (href[0] !== '#') {
          // remove the attribute (but keep the element)
          setHref(node, '');
          node.removeAttributeNS(NS.XLINK, 'href');
        }
      }
  
      // Safari crashes on a <use> without a xlink:href, so we just remove the node here
      if (node.nodeName === 'use' && !getHref(node)) {
        node.remove();
        return;
      }
      // if the element has attributes pointing to a non-local reference,
      // need to remove the attribute
      Object.values(['clip-path', 'fill', 'filter', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'stroke'], function (attr) {
        let val = node.getAttribute(attr);
        if (val) {
          val = getUrlFromAttr(val);
          // simply check for first character being a '#'
          if (val && val[0] !== '#') {
            node.setAttribute(attr, '');
            node.removeAttribute(attr);
          }
        }
      });
  
      // recurse to children
      i = node.childNodes.length;
      while (i--) { sanitizeSvg(node.childNodes.item(i)); }
    // else (element not supported), remove it
    } else {
      // remove all children from this node and insert them before this node
      // TODO: in the case of animation elements this will hardly ever be correct
      const children = [];
      while (node.hasChildNodes()) {
        children.push(parent.insertBefore(node.firstChild, node));
      }
  
      // remove this node from the document altogether
      node.remove();
  
      // call sanitizeSvg on each of those children
      let i = children.length;
      while (i--) { sanitizeSvg(children[i]); }
    }
  };
  