'use strict';

const suspectProtoRx = /"(?:_|\\u005[Ff])(?:_|\\u005[Ff])(?:p|\\u0070)(?:r|\\u0072)(?:o|\\u006[Ff])(?:t|\\u0074)(?:o|\\u006[Ff])(?:_|\\u005[Ff])(?:_|\\u005[Ff])"\s*:/;
const suspectConstructorRx = /"(?:c|\\u0063)(?:o|\\u006[Ff])(?:n|\\u006[Ee])(?:s|\\u0073)(?:t|\\u0074)(?:r|\\u0072)(?:u|\\u0075)(?:c|\\u0063)(?:t|\\u0074)(?:o|\\u006[Ff])(?:r|\\u0072)"\s*:/;
const JsonSigRx = /^["{[]|^-?[0-9][0-9.]{0,14}$/;
function jsonParseTransform(key, value) {
  if (key === "__proto__" || key === "constructor") {
    return;
  }
  return value;
}
function destr(val) {
  if (typeof val !== "string") {
    return val;
  }
  const _lval = val.toLowerCase();
  if (_lval === "true") {
    return true;
  }
  if (_lval === "false") {
    return false;
  }
  if (_lval === "null") {
    return null;
  }
  if (_lval === "nan") {
    return NaN;
  }
  if (_lval === "infinity") {
    return Infinity;
  }
  if (_lval === "undefined") {
    return void 0;
  }
  if (!JsonSigRx.test(val)) {
    return val;
  }
  try {
    if (suspectProtoRx.test(val) || suspectConstructorRx.test(val)) {
      return JSON.parse(val, jsonParseTransform);
    }
    return JSON.parse(val);
  } catch (_e) {
    return val;
  }
}

module.exports = destr;