/**
 * Module dependencies.
 */

const { DOMParser } = require("@xmldom/xmldom");

/**
 * Module exports.
 */

exports.parse = parse;

var TEXT_NODE = 3;
var CDATA_NODE = 4;
var COMMENT_NODE = 8;

/**
 * We ignore raw text (usually whitespace), <!-- xml comments -->,
 * and raw CDATA nodes.
 *
 * @param {Element} node
 * @returns {Boolean}
 * @api private
 */

function shouldIgnoreNode(node) {
  return (
    node.nodeType === TEXT_NODE ||
    node.nodeType === COMMENT_NODE ||
    node.nodeType === CDATA_NODE
  );
}

/**
 * Check if the node is empty. Some plist file has such node:
 * <key />
 * this node shoud be ignored.
 *
 * @see https://github.com/TooTallNate/plist.js/issues/66
 * @param {Element} node
 * @returns {Boolean}
 * @api private
 */
function isEmptyNode(node) {
  if (!node.childNodes || node.childNodes.length === 0) {
    return true;
  } else {
    return false;
  }
}

function invariant(test, message) {
  if (!test) {
    throw new Error(message);
  }
}

/**
 * Parses a Plist XML string. Returns an Object.
 *
 * @param {String} xml - the XML String to decode
 * @returns {Mixed} the decoded value from the Plist XML
 * @api public
 */

function parse(xml) {
  var doc = new DOMParser().parseFromString(xml, "text/xml");
  invariant(
    doc.documentElement.nodeName === "plist",
    "malformed document. First element should be <plist>",
  );
  var plist = parsePlistXML(doc.documentElement);

  // the root <plist> node gets interpreted as an Array,
  // so pull out the inner data first
  if (plist.length == 1) plist = plist[0];

  return plist;
}

/**
 * Convert an XML based plist document into a JSON representation.
 *
 * @param {Object} xml_node - current XML node in the plist
 * @returns {Mixed} built up JSON object
 * @api private
 */

function parsePlistXML(node) {
  var i, new_obj, key, val, new_arr, res, counter, type;

  if (!node) return null;

  if (node.nodeName === "plist") {
    new_arr = [];
    if (isEmptyNode(node)) {
      return new_arr;
    }
    for (i = 0; i < node.childNodes.length; i++) {
      if (!shouldIgnoreNode(node.childNodes[i])) {
        new_arr.push(parsePlistXML(node.childNodes[i]));
      }
    }
    return new_arr;
  } else if (node.nodeName === "dict") {
    new_obj = {};
    key = null;
    counter = 0;
    if (isEmptyNode(node)) {
      return new_obj;
    }
    for (i = 0; i < node.childNodes.length; i++) {
      if (shouldIgnoreNode(node.childNodes[i])) continue;
      if (counter % 2 === 0) {
        invariant(
          node.childNodes[i].nodeName === "key",
          "Missing key while parsing <dict/>.",
        );
        key = parsePlistXML(node.childNodes[i]);
      } else {
        invariant(
          node.childNodes[i].nodeName !== "key",
          'Unexpected key "' +
            parsePlistXML(node.childNodes[i]) +
            '" while parsing <dict/>.',
        );
        new_obj[key] = parsePlistXML(node.childNodes[i]);
      }
      counter += 1;
    }
    if (counter % 2 === 1) {
      new_obj[key] = "";
    }

    return new_obj;
  } else if (node.nodeName === "array") {
    new_arr = [];
    if (isEmptyNode(node)) {
      return new_arr;
    }
    for (i = 0; i < node.childNodes.length; i++) {
      if (!shouldIgnoreNode(node.childNodes[i])) {
        res = parsePlistXML(node.childNodes[i]);
        if (null != res) new_arr.push(res);
      }
    }
    return new_arr;
  } else if (node.nodeName === "#text") {
    // TODO: what should we do with text types? (CDATA sections)
  } else if (node.nodeName === "key") {
    if (isEmptyNode(node)) {
      return "";
    }

    invariant(
      node.childNodes[0].nodeValue !== "__proto__",
      "__proto__ keys can lead to prototype pollution. More details on CVE-2022-22912",
    );

    return node.childNodes[0].nodeValue;
  } else if (node.nodeName === "string") {
    res = "";
    if (isEmptyNode(node)) {
      return res;
    }
    for (i = 0; i < node.childNodes.length; i++) {
      var type = node.childNodes[i].nodeType;
      if (type === TEXT_NODE || type === CDATA_NODE) {
        res += node.childNodes[i].nodeValue;
      }
    }
    return res;
  } else if (node.nodeName === "integer") {
    invariant(!isEmptyNode(node), 'Cannot parse "" as integer.');
    return parseInt(node.childNodes[0].nodeValue, 10);
  } else if (node.nodeName === "real") {
    invariant(!isEmptyNode(node), 'Cannot parse "" as real.');
    res = "";
    for (i = 0; i < node.childNodes.length; i++) {
      if (node.childNodes[i].nodeType === TEXT_NODE) {
        res += node.childNodes[i].nodeValue;
      }
    }
    return parseFloat(res);
  } else if (node.nodeName === "data") {
    res = "";
    if (isEmptyNode(node)) {
      return Buffer.from(res, "base64");
    }
    for (i = 0; i < node.childNodes.length; i++) {
      if (node.childNodes[i].nodeType === TEXT_NODE) {
        res += node.childNodes[i].nodeValue.replace(/\s+/g, "");
      }
    }
    return Buffer.from(res, "base64");
  } else if (node.nodeName === "date") {
    invariant(!isEmptyNode(node), 'Cannot parse "" as Date.');
    return new Date(node.childNodes[0].nodeValue);
  } else if (node.nodeName === "null") {
    return null;
  } else if (node.nodeName === "true") {
    return true;
  } else if (node.nodeName === "false") {
    return false;
  } else {
    throw new Error("Invalid PLIST tag " + node.nodeName);
  }
}