在PHP中清理方式在段落上拆分字符串。扭曲：分隔符未知

Question

我正在运行一个WordPress插件，它处理内容并在X个段落之后插入一些东西。现在我的代码非常野蛮。样本：

$del = '</p>';
$para_count = substr_count($html, $del);

if($para_count == 0) {
    $del = "\r\n\r\n";
    $para_count = substr_count($html, $del); # echo "1";
}

if($para_count == 0) {
    $del = "\n\n\n\n";
    $para_count = substr_count($html, $del); # echo "2";
}

if($para_count == 0) {
    $del = '
';
    $para_count = round(substr_count($html, $del) / 2); # echo "3";
}       

if($para_count == 0) {
    $del = '<br/><br/>';
    $para_count = substr_count($html, $del); # echo "4";
} 

if($para_count == 0) {
    $del = '<br><br>';
    $para_count = substr_count($html, $del); # echo "5";
}

if($para_count == 0) {
    $del = '<br /><br />';
    $para_count = substr_count($html, $del); # echo "6";
}

if($para_count == 0) {
    return "<div class='display:none'><!-- NO DELIMETER FOUND --></div>".$html;
}

当来源未知时，找到段落分隔符的最佳方法是什么？我可以将脚本缩减为更简单的代码吗？