/* eslint-env browser */

var semicolon = 59 // `;`
/** @type {HTMLElement} */
var element

/**
 * @param {string} characters
 * @returns {string|false}
 */
export function decodeEntity(characters) {
  var entity = '&' + characters + ';'
  /** @type {string} */
  var char

  element = element || document.createElement('i')
  element.innerHTML = entity
  char = element.textContent

  // Some entities do not require the closing semicolon (`&not` - for instance),
  // which leads to situations where parsing the assumed entity of `&notit;`
  // will result in the string `¬it;`.
  // When we encounter a trailing semicolon after parsing and the entity to
  // decode was not a semicolon (`;`), we can assume that the matching was
  // incomplete
  if (char.charCodeAt(char.length - 1) === semicolon && characters !== 'semi') {
    return false
  }

  // If the decoded string is equal to the input, the entity was not valid
  return char === entity ? false : char
}