Terms Alphabet Catalog for Wordpress

catalog-template.php

<?php
/* Template Name: Catalog Template */

function renderAlphabetTermsCatalog($terms, $maxTermCountForLetter = 5) {
    $termsTitle = array_map(function($term) {
        return mb_convert_encoding($term->name, 'utf-8');
    }, $terms);

    $lastLetter = '';

    $termsForOneLetter = "";
    $termsCount = count($termsTitle);

    $columnIndex = 1;
    $columnTermIndex = 0;

    for($i = 0; $i < $termsCount; $i++) {
        $termTitle = $termsTitle[$i];
        $termLink = get_term_link($terms[$i], 'agencies');

        $currentLetter = mb_substr($termTitle, 0, 1, 'utf-8'); //first char
      
        $termLinkDom = ($columnTermIndex < $maxTermCountForLetter || $currentLetter !== $lastLetter || $i == 0) ?
            '<a class="catalog-agency-link" href="'.$termLink.'">'.$termTitle.'</a>' :
            '<a class="catalog-hidden-agency-link" href="'.$termLink.'">'.$termTitle.'</a>';

        if ($columnTermIndex == $maxTermCountForLetter && $currentLetter == $lastLetter) $termLinkDom .= '<a class="show-all-agencies-for-letter-btn" href="#">'.__('more...', 'canos').'</a>';

        $columnTermIndex++;

        //echo '<pre>'.$char.$lastChar.'</pre>';
        if ($currentLetter !== $lastLetter) {
            if ($i !== 0) {
                $shortcodeContent = generateShortcodeContent($lastLetter, $termsForOneLetter, $columnIndex%3 == 0);
                echo $shortcodeContent;

                $columnIndex++;
                $columnTermIndex = 1;
            }

            $termsForOneLetter = $termLinkDom;

            $lastLetter = $currentLetter;
        } else {
            $termsForOneLetter .= $termLinkDom;
        }

        if ($i == $termsCount - 1) {
            $shortcodeContent = generateShortcodeContent($lastLetter, $termsForOneLetter, $columnIndex%3 == 0);
            echo $shortcodeContent;
        }
    }
}

function generateShortcodeContent($letter, $content, $isLastColumn) {
    $columnHeader = '<div class="catalog-column-header">' . mb_strtoupper($letter, 'utf-8') . '</div>';
    $columnContent = '<div class="catalog-column-content">' . $content . '</div>';

    $shortcodeContent = $columnHeader.$columnContent;

    return $shortcodeContent;
}

get_header(); ?>

<h1>Terms Alphabet Catalog</h1>
<?php
$terms = get_terms([
  'taxonomy' => 'term_tax_type',
  'hide_empty' => false,
  'orderby' => 'name',
  'order' => 'ASC',
]);

renderAlphabetTermsCatalog($terms);
?>
  
<?php get_footer(); ?>