Calculates pages using mySQL offset/limit and renders html for a predefined amount of pages

pagination.php

<?php

$limit = 25;
$pageDisplayLimit = 10 - 1;
$currentPage = $offset / $limit + 1;
$totalPages = ceil($count / $limit);
$pagesRemaining = $totalPages - $currentPage;
$lastPageToDisplay = $currentPage + $pageDisplayLimit <= $totalPages
  ? $currentPage + $pageDisplayLimit
  : $totalPages;
$nextPageExists = $lastPageToDisplay < $totalPages;

if ($lastPageToDisplay === $totalPages) {
  $pageIndex = $totalPages - $pageDisplayLimit > 0
    ? $totalPages - $pageDisplayLimit
    : 1;
  $backBtnIndex = $pageIndex - ($pageDisplayLimit + 1) > 0
    ? $pageIndex - ($pageDisplayLimit + 1)
    : 1;
  $prevOffset = $backBtnIndex * $limit - $limit;
  $prevPageExists = $pageIndex > 1;
} else {
  $pageIndex = $currentPage;
  $backBtnIndex = $currentPage - ($pageDisplayLimit + 1) > 0
    ? $currentPage - ($pageDisplayLimit + 1)
    : 1;
  $prevOffset = $backBtnIndex * $limit - $limit;
  $prevPageExists = $currentPage > 1;
}

if ($prevPageExists) {
  $backBtn = <<<EOT
  <li><a href="#">&laquo;</a></li>
EOT;
  echo $backBtn;
}

for (; $pageIndex <= $lastPageToDisplay; $pageIndex++) {
  $pageOffset = ($limit * $pageIndex) - $limit;
  $activePage =  $pageIndex == $currentPage ? 'class="active-page"' : '';
  echo <<<EOT
  <li><a $activePage href="#">$pageIndex</a></li>
EOT;
}

if ($nextPageExists) {
  $thisOffset = $lastPageToDisplay * $limit;
  $nextBtn = <<<EOT
  <li><a href="#">&raquo;</a></li>
EOT;
  echo $nextBtn;
}