<?php
/**
 * @file
 * HTML entity utilities.
 */

namespace QueryPath;

/**
 * Perform various tasks on HTML/XML entities.
 *
 * @ingroup querypath_util
 */
class Entities {

  /**
   * This is three regexes wrapped into 1. The | divides them.
   * 1: Match any char-based entity. This will go in $matches[1]
   * 2: Match any num-based entity. This will go in $matches[2]
   * 3: Match any hex-based entry. This will go in $matches[3]
   * 4: Match any ampersand that is not an entity. This goes in $matches[4]
   *    This last rule will only match if one of the previous two has not already
   *    matched.
   * XXX: Are octal encodings for entities acceptable?
   */
  //protected static $regex = '/&([\w]+);|&#([\d]+);|&([\w]*[\s$]+)/m';
  protected static $regex = '/&([\w]+);|&#([\d]+);|&#(x[0-9a-fA-F]+);|(&)/m';

  /**
   * Replace all entities.
   * This will scan a string and will attempt to replace all
   * entities with their numeric equivalent. This will not work
   * with specialized entities.
   *
   * @param string $string
   *  The string to perform replacements on.
   * @return string
   *  Returns a string that is similar to the original one, but with
   *  all entity replacements made.
   */
  public static function replaceAllEntities($string) {
    return preg_replace_callback(self::$regex, '\QueryPath\Entities::doReplacement', $string);
  }

  /**
   * Callback for processing replacements.
   *
   * @param array $matches
   *  The regular expression replacement array.
   */
  protected static function doReplacement($matches) {
    // See how the regex above works out.
    //print_r($matches);

    // From count, we can tell whether we got a
    // char, num, or bare ampersand.
    $count = count($matches);
    switch ($count) {
      case 2:
        // We have a character entity
        return '&#' . self::replaceEntity($matches[1]) . ';';
      case 3:
      case 4:
        // we have a numeric entity
        return '&#' . $matches[$count-1] . ';';
      case 5:
        // We have an unescaped ampersand.
        return '&#38;';
    }
  }

  /**
   * Lookup an entity string's numeric equivalent.
   *
   * @param string $entity
   *  The entity whose numeric value is needed.
   * @return int
   *  The integer value corresponding to the entity.
   * @author Matt Butcher
   * @author Ryan Mahoney
   */
  public static function replaceEntity($entity) {
    return self::$entity_array[$entity];
  }

  /**
   * Conversion mapper for entities in HTML.
   * Large entity conversion table. This is
   * significantly broader in range than
   * get_html_translation_table(HTML_ENTITIES).
   *
   * This code comes from Rhizome ({@link http://code.google.com/p/sinciput})
   *
   * @todo See if we can do this as a const.
   * @see get_html_translation_table()
   */
  private static $entity_array = array(
    'nbsp' => 160, 'iexcl' => 161, 'cent' => 162, 'pound' => 163,
    'curren' => 164, 'yen' => 165, 'brvbar' => 166, 'sect' => 167,
    'uml' => 168, 'copy' => 169, 'ordf' => 170, 'laquo' => 171,
    'not' => 172, 'shy' => 173, 'reg' => 174, 'macr' => 175, 'deg' => 176,
    'plusmn' => 177, 'sup2' => 178, 'sup3' => 179, 'acute' => 180,
    'micro' => 181, 'para' => 182, 'middot' => 183, 'cedil' => 184,
    'sup1' => 185, 'ordm' => 186, 'raquo' => 187, 'frac14' => 188,
    'frac12' => 189, 'frac34' => 190, 'iquest' => 191, 'Agrave' => 192,
    'Aacute' => 193, 'Acirc' => 194, 'Atilde' => 195, 'Auml' => 196,
    'Aring' => 197, 'AElig' => 198, 'Ccedil' => 199, 'Egrave' => 200,
    'Eacute' => 201, 'Ecirc' => 202, 'Euml' => 203, 'Igrave' => 204,
    'Iacute' => 205, 'Icirc' => 206, 'Iuml' => 207, 'ETH' => 208,
    'Ntilde' => 209, 'Ograve' => 210, 'Oacute' => 211, 'Ocirc' => 212,
    'Otilde' => 213, 'Ouml' => 214, 'times' => 215, 'Oslash' => 216,
    'Ugrave' => 217, 'Uacute' => 218, 'Ucirc' => 219, 'Uuml' => 220,
    'Yacute' => 221, 'THORN' => 222, 'szlig' => 223, 'agrave' => 224,
    'aacute' => 225, 'acirc' => 226, 'atilde' => 227, 'auml' => 228,
    'aring' => 229, 'aelig' => 230, 'ccedil' => 231, 'egrave' => 232,
    'eacute' => 233, 'ecirc' => 234, 'euml' => 235, 'igrave' => 236,
    'iacute' => 237, 'icirc' => 238, 'iuml' => 239, 'eth' => 240,
    'ntilde' => 241, 'ograve' => 242, 'oacute' => 243, 'ocirc' => 244,
    'otilde' => 245, 'ouml' => 246, 'divide' => 247, 'oslash' => 248,
    'ugrave' => 249, 'uacute' => 250, 'ucirc' => 251, 'uuml' => 252,
    'yacute' => 253, 'thorn' => 254, 'yuml' => 255, 'quot' => 34,
    'amp' => 38, 'lt' => 60, 'gt' => 62, 'apos' => 39, 'OElig' => 338,
    'oelig' => 339, 'Scaron' => 352, 'scaron' => 353, 'Yuml' => 376,
    'circ' => 710, 'tilde' => 732, 'ensp' => 8194, 'emsp' => 8195,
    'thinsp' => 8201, 'zwnj' => 8204, 'zwj' => 8205, 'lrm' => 8206,
    'rlm' => 8207, 'ndash' => 8211, 'mdash' => 8212, 'lsquo' => 8216,
    'rsquo' => 8217, 'sbquo' => 8218, 'ldquo' => 8220, 'rdquo' => 8221,
    'bdquo' => 8222, 'dagger' => 8224, 'Dagger' => 8225, 'permil' => 8240,
    'lsaquo' => 8249, 'rsaquo' => 8250, 'euro' => 8364, 'fnof' => 402,
    'Alpha' => 913, 'Beta' => 914, 'Gamma' => 915, 'Delta' => 916,
    'Epsilon' => 917, 'Zeta' => 918, 'Eta' => 919, 'Theta' => 920,
    'Iota' => 921, 'Kappa' => 922, 'Lambda' => 923, 'Mu' => 924, 'Nu' => 925,
    'Xi' => 926, 'Omicron' => 927, 'Pi' => 928, 'Rho' => 929, 'Sigma' => 931,
    'Tau' => 932, 'Upsilon' => 933, 'Phi' => 934, 'Chi' => 935, 'Psi' => 936,
    'Omega' => 937, 'alpha' => 945, 'beta' => 946, 'gamma' => 947,
    'delta' => 948, 'epsilon' => 949, 'zeta' => 950, 'eta' => 951,
    'theta' => 952, 'iota' => 953, 'kappa' => 954, 'lambda' => 955,
    'mu' => 956, 'nu' => 957, 'xi' => 958, 'omicron' => 959, 'pi' => 960,
    'rho' => 961, 'sigmaf' => 962, 'sigma' => 963, 'tau' => 964,
    'upsilon' => 965, 'phi' => 966, 'chi' => 967, 'psi' => 968,
    'omega' => 969, 'thetasym' => 977, 'upsih' => 978, 'piv' => 982,
    'bull' => 8226, 'hellip' => 8230, 'prime' => 8242, 'Prime' => 8243,
    'oline' => 8254, 'frasl' => 8260, 'weierp' => 8472, 'image' => 8465,
    'real' => 8476, 'trade' => 8482, 'alefsym' => 8501, 'larr' => 8592,
    'uarr' => 8593, 'rarr' => 8594, 'darr' => 8595, 'harr' => 8596,
    'crarr' => 8629, 'lArr' => 8656, 'uArr' => 8657, 'rArr' => 8658,
    'dArr' => 8659, 'hArr' => 8660, 'forall' => 8704, 'part' => 8706,
    'exist' => 8707, 'empty' => 8709, 'nabla' => 8711, 'isin' => 8712,
    'notin' => 8713, 'ni' => 8715, 'prod' => 8719, 'sum' => 8721,
    'minus' => 8722, 'lowast' => 8727, 'radic' => 8730, 'prop' => 8733,
    'infin' => 8734, 'ang' => 8736, 'and' => 8743, 'or' => 8744, 'cap' => 8745,
    'cup' => 8746, 'int' => 8747, 'there4' => 8756, 'sim' => 8764,
    'cong' => 8773, 'asymp' => 8776, 'ne' => 8800, 'equiv' => 8801,
    'le' => 8804, 'ge' => 8805, 'sub' => 8834, 'sup' => 8835, 'nsub' => 8836,
    'sube' => 8838, 'supe' => 8839, 'oplus' => 8853, 'otimes' => 8855,
    'perp' => 8869, 'sdot' => 8901, 'lceil' => 8968, 'rceil' => 8969,
    'lfloor' => 8970, 'rfloor' => 8971, 'lang' => 9001, 'rang' => 9002,
    'loz' => 9674, 'spades' => 9824, 'clubs' => 9827, 'hearts' => 9829,
    'diams' => 9830
  );
}