// Hook into the user registration process
add_action('user_register', 'vap_send_friend_request_to_new_user', 10, 1);

function vap_send_friend_request_to_new_user($user_id) {
    // Check if BuddyPress is active
    if ( function_exists( 'bp_is_active' ) && bp_is_active('friends') ) {
        // Get the IDs of the users (sender and receiver)
        $sender_id = 1; // Replace with the actual sender's user ID
        $receiver_id = $user_id; // The newly registered user

        // Check if friendship doesn't already exist
        if ( ! friends_check_friendship( $sender_id, $receiver_id ) ) {
            // Send friend request
            $friendship_id = friends_add_friend( $sender_id, $receiver_id, true );

            if ( ! is_wp_error( $friendship_id ) ) {
                // Friend request sent successfully
                // You can log or output a success message here
                error_log('Friend request sent to user ID ' . $receiver_id);
            } else {
                // Error sending friend request
                // You can log or output an error message here
                error_log('Error sending friend request to user ID ' . $receiver_id . ': ' . $friendship_id->get_error_message());
            }
        } else {
            // Friendship already exists
            // You can log or output a message here
            error_log('Friendship already exists between users ' . $sender_id . ' and ' . $receiver_id);
        }
    }
}