chie/include/_category.php

<?php
function category_info(int $category): array {
    global $pdo;
    static $cats = [];

    if($category < 1)
        return [];

    if(!empty($cats[$category]))
        return $cats[$category];

    $getCat = $pdo->prepare('SELECT * FROM `fmf_categories` WHERE `cat_id` = :id');
    $getCat->bindValue('id', $category);
    $categoryInfo = $getCat->execute() ? $getCat->fetch(PDO::FETCH_ASSOC) : false;

    return $cats[$category] = ($categoryInfo ? $categoryInfo : []);
}

function category_children(int $parent = 0, int $recurse = 3): array {
    global $pdo;

    if($parent < 0)
        return [];

    $getCats = $pdo->prepare('SELECT * FROM `fmf_categories` WHERE `cat_parent` = :parent ORDER BY `cat_order`');
    $getCats->bindValue('parent', $parent);
    $categories = $getCats->execute() ? $getCats->fetchAll(PDO::FETCH_ASSOC) : false;
    $categories = $categories ? $categories : [];

    if($recurse > 0) {
        $recurse--;

        for($i = 0; $i < count($categories); $i++)
            $categories[$i]['children'] = category_children($categories[$i]['cat_id'], $recurse);
    }

    return $categories;
}

function root_category(): array {
    $categories = category_children();
    $forums = [];

    for($i = 0; $i < count($categories); $i++) {
        if($categories[$i]['cat_type'] != 1) {
            $forums[] = $categories[$i];
            unset($categories[$i]);
        }
    }

    if(count($forums) > 0)
        $categories[] = [
            'cat_id' => 0,
            'cat_type' => 1,
            'cat_name' => 'Categories',
            'children' => $forums,
        ];

    return $categories;
}

function category_bump(int $category, ?int $post = null, bool $topics = true, bool $posts = true): void {
    global $pdo;

    if($category < 1)
        return;

    $getParentId = $pdo->prepare('SELECT `cat_parent` FROM `fmf_categories` WHERE `cat_id` = :id');
    $getParentId->bindValue('id', $category);
    $parentId = $getParentId->execute() ? (int)$getParentId->fetchColumn() : 0;

    if($parentId > 0)
        category_bump($parentId, $post, $topics, $posts);

    $bump = $pdo->prepare('UPDATE `fmf_categories` SET `cat_count_topics` = IF(:topics, `cat_count_topics` + 1, `cat_count_topics`), `cat_count_posts` = IF(:posts, `cat_count_posts` + 1, `cat_count_posts`), `cat_last_post_id` = COALESCE(:post, `cat_last_post_id`) WHERE `cat_id` = :id');
    $bump->bindValue('topics', $topics ? 1 : 0);
    $bump->bindValue('posts', $posts ? 1 : 0);
    $bump->bindValue('post', $post);
    $bump->bindValue('id', $category);
    $bump->execute();
}

function category_breadcrumbs(int $category, bool $excludeSelf): array {
    global $pdo;

    $breadcrumbs = [];
    $getBreadcrumb = $pdo->prepare('
        SELECT `cat_id`, `cat_name`, `cat_parent`
        FROM `fmf_categories`
        WHERE `cat_id` = :category
    ');

    while($category > 0) {
        $getBreadcrumb->bindValue('category', $category);
        $breadcrumb = $getBreadcrumb->execute() ? $getBreadcrumb->fetch(PDO::FETCH_ASSOC) : [];

        if(empty($breadcrumb)) {
            break;
        }

        $breadcrumbs[] = $breadcrumb;
        $category = $breadcrumb['cat_parent'];
    }

    if($excludeSelf)
        $breadcrumbs = array_slice($breadcrumbs, 1);

    return array_reverse($breadcrumbs);
}

function category_child_ids(int $category): array {
    global $pdo;

    if($category < 1)
        return [];

    static $cached = [];

    if(isset($cached[$category]))
        return $cached[$category];

    $getChildren = $pdo->prepare('
        SELECT `cat_id`
        FROM `fmf_categories`
        WHERE `cat_parent` = :category
    ');
    $getChildren->bindValue('category', $category);
    $children = $getChildren->fetchAll(PDO::FETCH_ASSOC);

    return $cached[$category] = array_column($children, 'cat_id');
}