Clicking on categories throws "too many redirects" error

<?php 


include("inc/functions.php");

$pageTitle = "Catalog";
$section = null;
$items_per_page = 8;

if (isset($_GET["cat"])){
    if ($_GET["cat"]=="books") {
        $pageTitle = "Books";
        $section = "books";
    } else if ($_GET["cat"] == "movies") {
        $pageTitle = "Movies";
        $section = "movies";
    } else if ($_GET["cat"] == "music"){
        $pageTitle = "Music";
        $section = "music";
    }
}

if(isset($_GET["pg"])){
    $current_page = filter_input(INPUT_GET, "pg", FILTER_SANITIZE_NUMBER_INT);
}

if(empty($current_page)){
    $current_page = 1;
}



$total_items = get_catalog_count($section);

$total_pages = ceil($total_items / $items_per_page);


//limit results in redirect
$limit_results ="";
if(!empty($section)){
    $limit_results = "cat=" . $section ."&";
}



//redirect too-large page numbers to the last page
if($current_page > $total_pages){
    header("location:catalog.php?"
        . $limit_results
        ."pg="
        .$total_pages);
}
//redirect too-small page numbers to the first page
if($current_page < 1){
    header("location:catalog.php?"
            .$limit_results
            ."pg=1");
}

//determine the offset (number of items to skip) for the current page
//for example:on page 3 with 8 items per page, the offset would be 16

$offset = ($current_page - 1) * $items_per_page;
echo $offset;






if(empty($section)){
    $catalog = full_catalog_array(null, $offset);
} else {
    $catalog = category_catalog_array($section, $items_per_page, $offset);
}


include("inc/header.php");?>


<div class="section catalog page">
    <div class="wrapper">

        <h1><?php if ($section != null){
                    echo "<a href= 'catalog.php'>Full Catalog</a> &gt; ";
                }
            echo $pageTitle ?></h1>

        <ul class="items">
            <?php 



                foreach($catalog as $item){

                    echo get_item_html($item);
                }

             ?>

        </ul>



    </div>

</div>

<?php include("inc/footer.php") ?>