<?php

/* * *******************************************************************
 * Highlighter class - highlights SQL with preg and some compromises
 * @Author dzver <dzver@abv.bg>
 * @Copyright GNU v 3.0
 * ******************************************************************* */

class Highlighter {
    /*
      protected $colors - key order is important because of highlighting < and >
      chars and not encoding them to < and >
     */

    protected $colors = Array('chars' => 'grey', 'keywords' => 'blue', 'joins' => 'gray', 'functions' => 'violet', 'constants' => 'red');
    /*
      lists are not complete.
     */
    protected $words = Array(
        'keywords' =>
        array('SELECT', 'UPDATE', 'INSERT', 'DELETE', 'REPLACE', 'INTO', 'CREATE', 'ALTER', 'TABLE', 'DROP', 'TRUNCATE', 'FROM',
            'ADD', 'CHANGE', 'COLUMN', 'KEY',
            'WHERE', 'ON', 'CASE', 'WHEN', 'THEN', 'END', 'ELSE', 'AS',
            'USING', 'USE', 'INDEX', 'CONSTRAINT', 'REFERENCES', 'DUPLICATE',
            'LIMIT', 'OFFSET', 'SET', 'SHOW', 'STATUS',
            'BETWEEN', 'AND', 'IS', 'NOT', 'OR', 'XOR', 'INTERVAL', 'TOP',
            'GROUP BY', 'ORDER BY', 'DESC', 'ASC', 'COLLATE', 'NAMES', 'UTF8', 'DISTINCT', 'DATABASE',
            'CALC_FOUND_ROWS', 'SQL_NO_CACHE', 'MATCH', 'AGAINST', 'LIKE', 'REGEXP', 'RLIKE',
            'PRIMARY', 'AUTO_INCREMENT', 'DEFAULT', 'IDENTITY', 'VALUES', 'PROCEDURE', 'FUNCTION',
            'TRAN', 'TRANSACTION', 'COMMIT', 'ROLLBACK', 'SAVEPOINT', 'TRIGGER', 'CASCADE',
            'DECLARE', 'CURSOR', 'FOR', 'DEALLOCATE'
        ),
        'joins' => array('JOIN', 'INNER', 'OUTER', 'FULL', 'NATURAL', 'LEFT', 'RIGHT'),
        'chars' => '/([\\.,\\(\\)<>:=`]+)/i',
        'functions' => array(
            'MIN', 'MAX', 'SUM', 'COUNT', 'AVG', 'CAST', 'COALESCE', 'CHAR_LENGTH', 'LENGTH', 'SUBSTRING',
            'DAY', 'MONTH', 'YEAR', 'DATE_FORMAT', 'CRC32', 'CURDATE', 'SYSDATE', 'NOW', 'GETDATE',
            'FROM_UNIXTIME', 'FROM_DAYS', 'TO_DAYS', 'HOUR', 'IFNULL', 'ISNULL', 'NVL', 'NVL2',
            'INET_ATON', 'INET_NTOA', 'INSTR', 'FOUND_ROWS',
            'LAST_INSERT_ID', 'LCASE', 'LOWER', 'UCASE', 'UPPER',
            'LPAD', 'RPAD', 'RTRIM', 'LTRIM',
            'MD5', 'MINUTE', 'ROUND',
            'SECOND', 'SHA1', 'STDDEV', 'STR_TO_DATE', 'WEEK'),
        'constants' => '/(\'[^\']*\'|[0-9]+)/i'
    );

    /*
      $colors must be blank or
      Array('chars' => '', 'keywords' => '', 'joins' => '', 'functions' => '', 'constants' => '')
     */

    function __construct($colors = 0) {
        if ($colors)
            $this->colors = $colors;
    }

    public function highlight($sql) {
        $sql = str_replace('\\\'', '\\&#039;', $sql);
        foreach ($this->colors as $key => $color) {
            if (in_array($key, Array('constants', 'chars'))) {
                $regexp = $this->words[$key];
            } else {
                $regexp = '/\\b(' . join("|", $this->words[$key]) . ')\\b/i';
            }
            $sql = preg_replace($regexp, '<span style="color:' . $color . "\">$1</span>", $sql);
        }
        return $sql;
    }

}
?>