// Regexps to match html elements

'use strict';


function replace(regex, options) {
  regex = regex.source;
  options = options || '';

  return function self(name, val) {
    if (!name) {
      return new RegExp(regex, options);
    }
    val = val.source || val;
    regex = regex.replace(name, val);
    return self;
  };
}


var attr_name     = /[a-zA-Z_:][a-zA-Z0-9:._-]*/;

var unquoted      = /[^"'=<>`\x00-\x20]+/;
var single_quoted = /'[^']*'/;
var double_quoted = /"[^"]*"/;

/*eslint no-spaced-func:0*/
var attr_value  = replace(/(?:unquoted|single_quoted|double_quoted)/)
                    ('unquoted', unquoted)
                    ('single_quoted', single_quoted)
                    ('double_quoted', double_quoted)
                    ();

var attribute   = replace(/(?:\s+attr_name(?:\s*=\s*attr_value)?)/)
                    ('attr_name', attr_name)
                    ('attr_value', attr_value)
                    ();

var open_tag    = replace(/<[A-Za-z][A-Za-z0-9]*attribute*\s*\/?>/)
                    ('attribute', attribute)
                    ();

var close_tag   = /<\/[A-Za-z][A-Za-z0-9]*\s*>/;
var comment     = /<!---->|<!--(?:-?[^>-])(?:-?[^-])*-->/;
var processing  = /<[?].*?[?]>/;
var declaration = /<![A-Z]+\s+[^>]*>/;
var cdata       = /<!\[CDATA\[[\s\S]*?\]\]>/;

var HTML_TAG_RE = replace(/^(?:open_tag|close_tag|comment|processing|declaration|cdata)/)
  ('open_tag', open_tag)
  ('close_tag', close_tag)
  ('comment', comment)
  ('processing', processing)
  ('declaration', declaration)
  ('cdata', cdata)
  ();


module.exports.HTML_TAG_RE = HTML_TAG_RE;