'use strict';

let METADATA_SYMBOL;

if (typeof Symbol !== "function") {
  METADATA_SYMBOL = "@@xmlMetadata";
} else {
  METADATA_SYMBOL = Symbol("XML Node Metadata");
}

export default class XmlNode {
  constructor(tagname) {
    this.tagname = tagname;
    this.child = []; //nested tags, text, cdata, comments in order
    this[":@"] = Object.create(null); //attributes map
  }
  add(key, val) {
    // this.child.push( {name : key, val: val, isCdata: isCdata });
    if (key === "__proto__") key = "#__proto__";
    this.child.push({ [key]: val });
  }
  addChild(node, startIndex) {
    if (node.tagname === "__proto__") node.tagname = "#__proto__";
    if (node[":@"] && Object.keys(node[":@"]).length > 0) {
      this.child.push({ [node.tagname]: node.child, [":@"]: node[":@"] });
    } else {
      this.child.push({ [node.tagname]: node.child });
    }
    // if requested, add the startIndex
    this.addStartIndex(startIndex);
  }

  addStartIndex(startIndex) {
    if (startIndex !== undefined) {
      // Note: for now we just overwrite the metadata. If we had more complex metadata,
      // we might need to do an object append here:  metadata = { ...metadata, startIndex }
      this.child[this.child.length - 1][METADATA_SYMBOL] = { startIndex };
    }
  }

  addEndIndex(endIndex) {
    const lastChild = this.child[this.child.length - 1];
    // endIndex is write-once: when updateTag drops a node, the last child is a
    // previously completed sibling whose endIndex must not be overwritten
    if (lastChild !== undefined && lastChild[METADATA_SYMBOL] !== undefined
      && lastChild[METADATA_SYMBOL].endIndex === undefined) {
      lastChild[METADATA_SYMBOL].endIndex = endIndex;
    }
  }
  /** symbol used for metadata */
  static getMetaDataSymbol() {
    return METADATA_SYMBOL;
  }
}