/**
 * 高亮问题修正, 排除alt title <a></a>直接的字符替换
 * @param string $kw
 * @param string $body
 * @return string
 */
function ReplaceKeyword($kw,&$body)
{
    global $cfg_cmspath;
    $maxkey = 5;
    $kws = explode(",",trim($kw)); //以分号为间隔符
    $i=0;
    $karr = $kaarr = $GLOBALS['replaced'] = array();
    
    // 暂时屏蔽超链接
    $body = preg_replace("#(<a(.*))(>)(.*)(<)(/a>)#isU", "\\1-]-\\4-[-\\6", $body);
    
    $query="SELECT * FROM `keywords` WHERE rpurl<>'' and sta=1 ORDER BY length(keyword) DESC"; // 修改优先处理长关键词
    $this->dsql->SetQuery($query);
    $this->dsql->Execute();
    
    while($row = $this->dsql->GetArray())
    {
        $key = trim($row['keyword']);
        $key_url=trim($row['rpurl']);
        $karr[] = $key;
        $kaarr[] = "<a class='title-prefix' href='$key_url' target='_blank'>$key</a>"; // 删除 <u> 和 </u> ，增加class属性
    }
    
    foreach ($karr as $key => $word)
    {
        $body = preg_replace("/(^|>)([^<]+)(?=<|$)/sUe", "_highlight('\\2', $karr[$key], $kaarr[$key], '\\1')", $body);
        
        // 恢复超链接
        $body = preg_replace("/(<a(.*))-]-(.*)-[-(/a>)/isU", "\\1>\\3<\\4", $body);
    }
    
    return $body;
}

// 高亮专用, 替换多次是可能不能达到最多次
function _highlight($string, $words, $result, $pre)
{
    global $cfg_replace_num;
    $string = str_replace('"', '"', $string);
    
    if($GLOBALS['replaced'][$words] == 1){
        return $pre.$string;
    }
    
    if($cfg_replace_num > 0)
    {
        $string = preg_replace("#".preg_quote($words)."#", $result, $string, $cfg_replace_num); // 修改后
        
        if(strpos($string, $words) !== FALSE)
        {
            $GLOBALS['replaced'][$words] = 1;
        }
    }
    else
    {
        $string = str_replace($words, $result, $string);
    }
    
    return $pre.$string;
}