Comment App for Post Authors

/**
 * Insert Comment Appreciation
 * Lets insert the mycred_send shortcode after the comment
 * text if a user can afford to use it (and is logged in.
 * @version 1.0.1
 */
add_filter( 'comment_text', 'my_custom_comment_text', 10, 2 );
function my_custom_comment_text( $comment_text, $comment = NULL ) {

    // Make sure the current user is logged in
    if ( ! is_user_logged_in() || $comment === NULL || $comment->user_id == 0 || is_admin() )
    return $comment_text;

    // Prep
    $mycred = mycred();
    $cui = get_current_user_id();

    // Make sure the current user is not the comment author
    if ( $cui == $comment->user_id ) return $comment_text;

    // Make sure the current user is not excldued
    if ( $mycred->exclude_user( $cui ) ) return $comment_text;

    // Make sure the comment author is not excluded
    if ( $mycred->exclude_user( $comment->user_id ) ) return $comment_text;

    // Prep shortcode details
    $user_id = $comment->user_id;
    $amount  = 1;
    $label   = 'Give 1 Point';
    $ref     = 'comment_appreciation';
    $entry   = 'Comment Appreciation';

    // Make sure only the post author sees the button
    $post = get_post( $comment->comment_post_ID );
    if ( isset( $post->post_author ) && $cui != $post->post_author ) return $comment_text;

    // Append shortcode to the end of the comment text
    $add_points = '[mycred_send to="' . $user_id . '" amount="' . $amount . '" log="' . $entry . '"]' . $label . '[/mycred_send]';
    $comment_text .= '
    <div class="comment-like">' . do_shortcode( $add_points ) . '</div>';

    // Return result
    return $comment_text;

}