'use strict';

const createContent = (m => m.__esModule ? /* istanbul ignore next */ m.default : /* istanbul ignore next */ m)(require('@ungap/create-content'));

const {indexOf} = require('uarray');

// from a generic path, retrieves the exact targeted node

const reducePath = ({childNodes}, i) => childNodes[i];

exports.reducePath = reducePath;

// from a fragment container, create an array of indexes

// related to its child nodes, so that it's possible

// to retrieve later on exact node via reducePath

const createPath = node => {

const path = [];

let {parentNode} = node;

while (parentNode) {

path.push(indexOf.call(parentNode.childNodes, node));

node = parentNode;

parentNode = node.parentNode;

}

return path;

};

exports.createPath = createPath;

const {createTreeWalker, importNode} = document;

exports.createTreeWalker = createTreeWalker;

exports.importNode = importNode;

// this "hack" tells the library if the browser is IE11 or old Edge

const isImportNodeLengthWrong = importNode.length != 1;

// IE11 and old Edge discard empty nodes when cloning, potentially

// resulting in broken paths to find updates. The workaround here

// is to import once, upfront, the fragment that will be cloned

// later on, so that paths are retrieved from one already parsed,

// hence without missing child nodes once re-cloned.

const createFragment = isImportNodeLengthWrong ?

(text, type, normalize) => importNode.call(

document,

createContent(text, type, normalize),

true

) :

createContent;

exports.createFragment = createFragment;

// IE11 and old Edge have a different createTreeWalker signature that

// has been deprecated in other browsers. This export is needed only

// to guarantee the TreeWalker doesn't show warnings and, ultimately, works

const createWalker = isImportNodeLengthWrong ?

fragment => createTreeWalker.call(document, fragment, 1 | 128, null, false) :

fragment => createTreeWalker.call(document, fragment, 1 | 128);

exports.createWalker = createWalker;