Epic News Elements || Primary Category Filter

/**
 * Epic News Elements || Primary Category Filter
 */
if ( ! function_exists( 'custom_epic_primary_category' ) ) {
    /**
     * Custom Filter for Epic Primary Category
     *
     * @param int      $category_id Category ID.
     * @param null|int $post_id Post ID.
     *
     * @return int
     */
    function custom_epic_primary_category( $category_id, $post_id, $recursive = false ) {
        if ( $recursive ) {
            $check_category = get_category( $category_id );

            if ( $check_category->parent === 0 ) {
                return $check_category->term_id;
            }

            return custom_epic_primary_category( $category->parent, $post_id, true );
        }

        $categories            = get_the_category( $post_id );
        $primary_cateories_ids = array();

        foreach ( $categories as $category ) {
            if ( $category->parent === 0 ) {
                $primary_cateories_ids[] = $category->term_id;
            } else {
                $primary_cateories_ids[] = custom_epic_primary_category( $category->parent, $post_id, true );
            }
        }

        return array_shift( $primary_cateories_ids );
    }

    add_filter( 'epic_primary_category', 'custom_epic_primary_category', 10, 2 );
}