Sort WooCommerce products by the highest discount using JetSmartFilters

To sort your WooCommerce products by the highest discount using JetSmartFilters' **Sort Filter**, you can use the following steps and PHP snippet:

---

### **1. Add a Custom Meta Key for Discount Calculation**
You need to calculate and store the discount as a custom meta key for each product. This meta key will be used in the JetSmartFilters Sort Filter.

Add the following PHP snippet to your theme's `functions.php` file or a custom plugin:

```php
add_action('save_post_product', 'update_product_discount_meta');
function update_product_discount_meta($post_id) {
    // Ensure it's a product post type
    if (get_post_type($post_id) !== 'product') {
        return;
    }

    // Get the product object
    $product = wc_get_product($post_id);
    if (!$product) {
        return;
    }

    // Get the regular and sale prices
    $regular_price = (float) $product->get_regular_price();
    $sale_price = (float) $product->get_sale_price();

    // Calculate the discount percentage
    if ($regular_price > 0 && $sale_price > 0) {
        $discount = round((($regular_price - $sale_price) / $regular_price) * 100);
    } else {
        $discount = 0; // No discount
    }

    // Update the custom field with the discount value
    update_post_meta($post_id, '_product_discount', $discount);
}
```

---

### **2. Recalculate Discounts for Existing Products**
To apply the discount calculation to existing products, you can run a script or use a plugin like **WP Crontrol** to loop through all products and update their discounts.

```php
add_action('init', 'recalculate_discounts_for_all_products');
function recalculate_discounts_for_all_products() {
    $args = array(
        'post_type' => 'product',
        'posts_per_page' => -1,
        'fields' => 'ids',
    );
    $products = get_posts($args);

    foreach ($products as $product_id) {
        update_product_discount_meta($product_id);
    }
}
```
This will process all products and save their discounts. After running it once, you can remove or comment out this action.

---

### **3. Configure the JetSmartFilters Sort Filter**
In the **Sort Filter** settings (as shown in your screenshot):
1. **Order By**: Select **Meta Key Numeric** (since the discount is a number).
2. **Key**: Enter `_product_discount` (the meta key used in the PHP snippet).
3. **Order**: Set to **DESC** (to sort from highest to lowest discount).

---

### **4. Test the Sorting**
- Add the JetSmartFilters **Sort Filter** to the page where your product listing grid is displayed.
- Ensure the sorting works as expected, with the products having the highest discount appearing first.