Woocommerce add variable product

function matterhorn_insert_product($product_data){

    $post_id = wp_insert_post( array(
        'post_author' => 1,
        'post_title' => $product_data['mh_name'],
        'post_content' => $product_data['mh_desc'],
        'post_status' => 'publish',
        'post_type' => "product",
    ) );
    wp_set_object_terms( $post_id, 'variable', 'product_type' );

// /////////////////////////////////////////////////
    $product = wc_get_product($post_id);
    update_post_meta( $post_id, 'pk_mh_sale_price',$product_data['mh_sale'] );
    update_post_meta( $post_id, 'pk_mh_price',$product_data['mh_price'] );
    create_product_attributes($post_id,$product_data['mh_sizes']);
    foreach ($product_data['mh_sizes'] as $attribute => $qty )
    {
        $variation_data =  array(
            'attributes' => array(
                'size'  => $attribute,
            
            ),
            'sku'           => '',
            'regular_price' => '22.00',
            'sale_price'    => '',
            'stock_qty'     => $qty,
        );
        
        create_product_variation($post_id, $variation_data, $attribute);
        
    }

}
function create_product_variation($product_id, $variation_data, $attr){
    $product = wc_get_product($product_id);
    $variation_post = array(
        'post_title'  => $product->get_name()." - ".$attr,
        'post_content' => '',
        'post_status' => 'publish',
        'post_parent' => $product_id,
        'post_type'   => 'product_variation',
        'guid'        => $product->get_permalink()
    );
    // Creating the product variation
    $variation_id = wp_insert_post( $variation_post );
    
    // Get an instance of the WC_Product_Variation object
    $variation = new WC_Product_Variation( $variation_id );

   
    foreach ($variation_data['attributes'] as $attribute => $term_name )
    {
        $taxonomy = 'pa_'.$attribute; // The attribute taxonomy

        // If taxonomy doesn't exists we create it (Thanks to Carl F. Corneil)
        if( ! taxonomy_exists( $taxonomy ) ){
            register_taxonomy(
                $taxonomy,
               'product_variation',
                array(
                    'hierarchical' => false,
                    'label' => ucfirst( $attribute ),
                    'query_var' => true,
                    'rewrite' => array( 'slug' => sanitize_title($attribute) ), // The base slug
                ),
            );
        }

        // Check if the Term name exist and if not we create it.
        if( ! term_exists( $term_name, $taxonomy ) )
            wp_insert_term( $term_name, $taxonomy ); // Create the term

        $term_slug = get_term_by('name', $term_name, $taxonomy )->slug; // Get the term slug

        // Get the post Terms names from the parent variable product.
        $post_term_names =  wp_get_post_terms( $product_id, $taxonomy, array('fields' => 'names') );

        // Check if the post term exist and if not we set it in the parent variable product.
        if( ! in_array( $term_name, $post_term_names ) )
            wp_set_post_terms( $product_id, $term_name, $taxonomy, true );

        // Set/save the attribute data in the product variation
        update_post_meta( $variation_id, 'attribute_'.sanitize_title($attribute), $term_name );
        
        WC_Product_Variable::sync( $product_id );
    }

    ## Set/save all other data

    // SKU
    if( ! empty( $variation_data['sku'] ) )
        $variation->set_sku( $variation_data['sku'] );

    // Prices
    if( empty( $variation_data['sale_price'] ) ){
        $variation->set_price( $variation_data['regular_price'] );
    } else {
        $variation->set_price( $variation_data['sale_price'] );
        $variation->set_sale_price( $variation_data['sale_price'] );
    }
    $variation->set_regular_price( $variation_data['regular_price'] );

    // Stock
    if( ! empty($variation_data['stock_qty']) ){
        $variation->set_stock_quantity( $variation_data['stock_qty'] );
        $variation->set_manage_stock(true);
        $variation->set_stock_status('');
    } else {
        $variation->set_manage_stock(false);
    }

    $variation->set_weight(''); // weight (reseting)

    $variation->save(); // Save the data
    echo 'ok';
}
function create_product_attributes($post_id,$attr)
{
    $my_sizes="";
    foreach ($attr as $attribute => $qty )
    {
        $my_sizes.=$attribute."|";
    }
    $product_attributes = array 
    (
        "size" =>  substr($my_sizes, 0, -1),
    //   size=> "XL|L|M"
    );

    foreach($product_attributes as $attribute_name => $values)
    {
        wp_set_object_terms($post_id, $values, $attribute_name);

        $attributes[sanitize_title($attribute_name)] = array
        (
            'name'          => wc_clean( $attribute_name ),
            'value'         => $values,
            'is_visible'    => 1, 
            'is_variation'  => 1,
            'is_taxonomy'   => 0
        );

        // update it back
        update_post_meta($post_id, '_product_attributes', $attributes );
    }
}