'use strict'

var attributeName = '[a-zA-Z_:][a-zA-Z0-9:._-]*'
var unquoted = '[^"\'=<>`\\u0000-\\u0020]+'
var singleQuoted = "'[^']*'"
var doubleQuoted = '"[^"]*"'
var attributeValue =
  '(?:' + unquoted + '|' + singleQuoted + '|' + doubleQuoted + ')'
var attribute =
  '(?:\\s+' + attributeName + '(?:\\s*=\\s*' + attributeValue + ')?)'
var openTag = '<[A-Za-z][A-Za-z0-9\\-]*' + attribute + '*\\s*\\/?>'
var closeTag = '<\\/[A-Za-z][A-Za-z0-9\\-]*\\s*>'
var comment = '<!---->|<!--(?:-?[^>-])(?:-?[^-])*-->'
var processing = '<[?].*?[?]>'
var declaration = '<![A-Za-z]+\\s+[^>]*>'
var cdata = '<!\\[CDATA\\[[\\s\\S]*?\\]\\]>'

exports.openCloseTag = new RegExp('^(?:' + openTag + '|' + closeTag + ')')

exports.tag = new RegExp(
  '^(?:' +
    openTag +
    '|' +
    closeTag +
    '|' +
    comment +
    '|' +
    processing +
    '|' +
    declaration +
    '|' +
    cdata +
    ')'
)