Query of multiple Mysql data

Question

I’m doing a chat and I have the following table in the bank:

I want to list the last 5 conversations of a user, but the query is very complex, I’m for a while trying to solve with Queries, but I didn’t get anything, it should meet the following requirements:

• The user in question can be both a sender (sender_id) as a recipient (recipient_id), then you have to fetch both, and when the user is sender_id, the recipient_id has to receive a alias to be a user_id (See the code below);
• Results should be ordered in DESC;
• You must return the last message of the conversation;
• The message cannot be deleted for the user in question (I used as Boolean 0 for no and 1 for yes).

The codes:

-Where I list the messages:

<?php foreach($list_messages as $msg) : ?>
        <?php $recipient = find_user($con, $msg['user_id']); ?>
        <a href="#" onclick="openPanelChat(<?php echo $recipient['user_id'] ?>)" class="dropdown-notification-content" style="background-color: <?php echo ($msg['seen'] == 0) ? 'rgba(28,146,243,0.08)' : 'white' ?>">
            <img src="<?php echo $recipient['picture'] ?>">
            <b><?php echo $recipient['name'] ?></b>
            <p><?php echo base64_decode($msg['msg']) ?></p>
            <span><?php echo translateDateFull($msg['registry']); ?></span>
        </a>
<?php endforeach; ?>

-The function that lists and returns everything in an array

function list_messages($con, $user_id){
    $list_sql = "Essa é a consulta que quero!";
    $r = mysqli_query($con, $list_sql) or die(mysqli_error());
    $messages = array();
    while($each = mysqli_fetch_assoc($r)){
        $messages[] = $each;
    }
    return $messages;
}

Example of a conversation between id=27 and id=31. This is a conversation, let’s assume that this id=27 is me "Artur" and 31 is "Vitória", I want to display the last message of our conversation, but I (id=27) can be both sender_id and recipient_id: Well, that’s it, the result should be something like the one on facebook!