/**
 * Tools for SVG sanitization.
 * @module sanitize
 * @license MIT
 *
 * @copyright 2010 Alexis Deveria, 2010 Jeff Schiller
 */

import { getReverseNS, NS } from '../common/namespaces.js';
import { isGecko } from '../common/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}
 */
/* eslint-disable max-len */
const svgGenericWhiteList = [ 'class', 'id', 'display', 'transform' ];
const svgWhiteList_ = {
  // SVG Elements
  a: [ 'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'mask', 'opacity', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'xlink:href', 'xlink:title' ],
  circle: [ 'clip-path', 'clip-rule', 'cx', 'cy', 'enable-background', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'mask', 'opacity', 'r', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage' ],
  clipPath: [ 'clipPathUnits', 'id' ],
  defs: [],
  style: [ 'type' ],
  desc: [],
  ellipse: [ 'clip-path', 'clip-rule', 'cx', 'cy', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'mask', 'opacity', 'requiredFeatures', 'rx', 'ry', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage' ],
  feBlend: [ 'in', 'in2' ],
  feColorMatrix: [ 'in', 'type', 'value', 'result', 'values' ],
  feComposite: [ 'in', 'operator', 'result', 'in2' ],
  feFlood: [ 'flood-color', 'in',  'result', 'flood-opacity' ],
  feGaussianBlur: [  'color-interpolation-filters',  'in', 'requiredFeatures', 'stdDeviation', 'result' ],
  feMerge: [],
  feMergeNode: [ 'in' ],
  feMorphology: [ 'in', 'operator', 'radius' ],
  feOffset: [ 'dx', 'in', 'dy', 'result' ],
  filter: [ 'color-interpolation-filters', 'filterRes', 'filterUnits', 'height',  'primitiveUnits', 'requiredFeatures', 'style', 'width', 'x', 'xlink:href', 'y' ],
  foreignObject: [  'font-size', 'height',  'opacity', 'requiredFeatures', 'style', 'width', 'x', 'y' ],
  g: [ 'clip-path', 'clip-rule',   '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', 'font-family', 'font-size', 'font-style', 'font-weight', 'text-anchor' ],
  image: [  'clip-path', 'clip-rule', 'filter', 'height',  'mask', 'opacity', 'requiredFeatures', 'style', 'systemLanguage', 'width', 'x', 'xlink:href', 'xlink:title', 'y' ],
  line: [  'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter',  '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', 'x1', 'x2', 'y1', 'y2' ],
  linearGradient: [   'gradientTransform', 'gradientUnits', 'requiredFeatures', 'spreadMethod', 'systemLanguage', 'x1', 'x2', 'xlink:href', 'y1', 'y2' ],
  marker: [   'markerHeight', 'markerUnits', 'markerWidth', 'orient', 'preserveAspectRatio', 'refX', 'refY', 'systemLanguage', 'viewBox' ],
  mask: [  'height',  'maskContentUnits', 'maskUnits', 'width', 'x', 'y' ],
  metadata: [  'id' ],
  path: [  'clip-path', 'clip-rule', 'd', 'enable-background', 'fill', 'fill-opacity', 'fill-rule', 'filter',  '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' ],
  pattern: [  'height',  'patternContentUnits', 'patternTransform', 'patternUnits', 'requiredFeatures', 'style', 'systemLanguage', 'viewBox', 'width', 'x', 'xlink:href', 'y' ],
  polygon: [  'clip-path', 'clip-rule',  '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', 'sides', 'shape', 'edge', 'point', 'starRadiusMultiplier', 'r', 'radialshift' ],
  polyline: [  'clip-path', 'clip-rule',  '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', 'se:connector' ],
  radialGradient: [  'cx', 'cy', 'fx', 'fy', 'gradientTransform', 'gradientUnits',  'r', 'requiredFeatures', 'spreadMethod', 'systemLanguage', 'xlink:href' ],
  rect: [  'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'height',  'mask', 'opacity', 'requiredFeatures', 'rx', 'ry', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'width', 'x', 'y' ],
  stop: [   'offset', 'requiredFeatures', 'stop-opacity', 'style', 'systemLanguage', 'stop-color', 'gradientUnits', 'gradientTransform' ],
  svg: [  'clip-path', 'clip-rule', 'enable-background', 'filter',  'height', 'mask', 'preserveAspectRatio', 'requiredFeatures', 'style', 'systemLanguage', 'version', 'viewBox', 'width', 'x', 'xmlns', 'xmlns:se', 'xmlns:xlink', 'xmlns:oi', 'oi:animations', 'y', 'stroke-linejoin', 'fill-rule', 'aria-label', 'stroke-width', 'fill-rule', 'xml:space' ],
  switch: [   'requiredFeatures', 'systemLanguage' ],
  symbol: [  'fill', 'fill-opacity', 'fill-rule', 'filter', 'font-family', 'font-size', 'font-style', 'font-weight',  'opacity', 'overflow', 'preserveAspectRatio', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'viewBox', 'width', 'height' ],
  text: [  'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'font-family', 'font-size', 'font-style', 'font-weight',  'mask', 'opacity', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'text-anchor', 'x', 'xml:space', 'y' ],
  textPath: [   'method', 'requiredFeatures', 'spacing', 'startOffset', 'style', 'systemLanguage', 'xlink:href' ],
  title: [],
  tspan: [  'clip-path', 'clip-rule', 'dx', 'dy', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'font-family', 'font-size', 'font-style', 'font-weight',  'mask', 'opacity', 'requiredFeatures', 'rotate', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'text-anchor', 'textLength', 'x', 'xml:space', 'y' ],
  use: [  'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'height',  'mask', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'width', 'x', 'xlink:href', 'y', 'overflow' ],

  // MathML Elements
  annotation: [ 'encoding' ],
  'annotation-xml': [ 'encoding' ],
  maction: [ 'actiontype', 'other', 'selection' ],
  math: [    '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: []
};
/* eslint-enable max-len */
// add generic attributes to all elements of the whitelist
Object.keys(svgWhiteList_).forEach((element) => svgWhiteList_[element] = [ ...svgWhiteList_[element], ...svgGenericWhiteList ]);
// Produce a Namespace-aware version of svgWhitelist
const svgWhiteListNS_ = {};
Object.entries(svgWhiteList_).forEach(([ 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.trim();
    // 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
      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])) {
        // 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 ]);
        }
        console.warn(`sanitizeSvg: attribute ${attrName} in element ${node.nodeName} not in whitelist is removed`);
        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) && href[0] !== '#') {
      // remove the attribute (but keep the element)
      setHref(node, '');
      console.warn(`sanitizeSvg: attribute href in element ${node.nodeName} pointing to a non-local reference (${href}) is removed`);
      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)) {
      console.warn(`sanitizeSvg: element ${node.nodeName} without a xlink:href is removed`);
      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, '');
          console.warn(`sanitizeSvg: attribute ${attr} in element ${node.nodeName} pointing to a non-local reference (${val}) is removed`);
          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
    console.warn(`sanitizeSvg: element ${node.nodeName} not supported is removed`);
    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]); }
  }
};
