How to check if `comment_meta` exists before inserting the comment?

Question

I am inserting comments via wp_insert_comment and while doing so I am adding email replies only. Now, I want to check if the comment is already present or not before inserting and if does exist do not perform wp_insert_comment. Here, is my code:

 // Here, we insert the replies as comment to their parent email. 
            if ((!empty($mail['header']->references )) && (preg_replace('~[<]~','',strstr($mail['header']->references, '@',true))) == (preg_replace('~[<]~','',strstr($mail['header']->references, '@',true))))     
                {
                  //echo htmlentities($mail['header']->message_id);

                $posts = get_posts( array(
                    'post_type'  => 'post-type',
                    'meta_key'   => 'ticket_id',
                    'meta_value' => preg_replace('~[<]~','',strstr($mail['header']->references, '@',true)),
                ) );
                    
            if ( ! empty( $posts )   ) {
                $comment_array = array(
                    'comment_content' => $mail['body'],
                    'comment_post_ID' => $posts[0]->ID,
                    'comment_author'  => ucwords(strstr($mail['header']->fromaddress, '<',true)),
                    'comment_author_email' => preg_replace('~[<>]~', '', strstr($mail['header']->fromaddress, '<')),
                    'comment_type'  => 'email_replies',
                    'comment_date'  => $mail['header']->Date,
                    'comment_meta'  => preg_replace('~[<]~','',strstr($mail['header']->message_id, '@',true)),
                );
                   wp_insert_comment($comment_array);
            }
            }

I am a still beginner so any help will be much appreciated.

Answer 1

First off, you need to fix the comment_meta value. It should be an array of meta key and value pairs, and not just the meta value.

So give the meta a key (or name), e.g. message_id, and then do something like so:

'comment_meta' => array(
    'message_id' => preg_replace('~[<]~','',strstr($mail['header']->message_id, '@',true)),
),

Now to check if a comment already exists by a specific meta, you can use get_comments() and the meta query, just like you did using get_posts().

So for example:

$comment_exists = (bool) get_comments( array(
    'type'       => 'email_replies',
    'meta_key'   => 'message_id',
    'meta_value' => preg_replace('~[<]~','',strstr($mail['header']->message_id, '@',true)),
    'count'      => true, // this means we're retrieving the number of comments only
) );

if ( ! $comment_exists ) {
    $posts = get_posts( ... );

    if ( ! empty( $posts ) ) {
        // insert the comment
    }
}

And BTW, you should assign the above preg_replace()'s value to a variable and then use it with the comment_meta and meta_value above.