disable user interaction if they are the last ones on a $x value

So i've banging my head to the wall for the last 2 days So my issue is with this line

elseif ($current_user->ID == $bhistory['userid'])

i want the users to get error, if they are the last ones of $bhistory

my issue is that its not working, users are the last ones of $bhistory and they still able to click and be the last ones again and again and again of $bhistory again.

also please can someone explain this line of code in english

foreach($bidding_history as $kk => $bhistory){

<?php
    $bidding_history = $current_bidding_data;
    if(is_array($bidding_history) && !empty($bidding_history) ){ 
    ?>

        <ul class="list-group">
        <?php

        foreach($bidding_history as $kk => $bhistory){
        ?>
        <li class="list-group-item"><span class="badge pull-right"><small><?php echo $bhistory['username'] ?></small></span> <small><a href=""><?php echo $bhistory['userid']; ?></a></small></li>
        <?php } ?>
        </ul>

    <?php }else{ ?>

    <div class="text-center"><h4><?php echo $CORE->_e(array('auction','87')); ?></h4></div>

<?php
global $current_user;
$current_user = wp_get_current_user();
// MAKE BID OPTIONS
if($auction_type != 2){

    // BIDDING DATA
    $BIDDINGSTRING = "";

    // CHECK IF THIS IS AN AFFILIATE PRODUCT OR NOT
    $aff_p = get_post_meta($post->ID,'buy_link',true);
    if(strlen($aff_p) > 1){
    $link_l = get_home_url()."/out/".$post->ID."/buy_link/";
    $btn_l = "<a href='".$link_l."' class='btn btn-primary right'>".$CORE->_e(array('auction','53'))."</a>";

    // STOP BIDDING ON OWN ITEMS & IF LAST BIDDER
    }elseif ($current_user->ID == $bhistory['userid']){
    $btn_l = "<button class='btn' href='javascript:void(0);' onclick=\"alert('".$CORE->_e(array('auction','54'))."');\" id='bid_button'>".$CORE->_e(array('auction','70'))."</button>";
    }else{ if($userdata->ID == $post->post_author) {
    $btn_l = "<button class='btn' href='javascript:void(0);' onclick=\"alert('".$CORE->_e(array('auction','54','flag_noedit'))."');\" id='bid_button'>".$CORE->_e(array('auction','70'))."</button>";
    }else{
    $btn_l = "<button class='btn' href='javascript:void(0);' onclick=\"UpdateBidding();\" id='bid_button'>".$CORE->_e(array('auction','70'))."</button>";
    }
    }

S