php - Mandatory redemption coupon for gifted items in WooCommerce

I'm using the below function which currently accepts a single (or array of) static coupon codes. How can I change this to work with any valid (i.e. not already used the maximum times etc.) coupon code that exists in the site?

add_action( 'woocommerce_check_cart_items', 'mandatory_coupon_code' );

function mandatory_coupon_code() {
    $product_categories = array( 'gifts' ); // Category ID or slug of targeted category

    // NEED TO EDIT THIS PART TO GET THE LIST OF VALID CODES
    $coupon_code = 'testing1'; // The required coupon code

    $coupon_applied = in_array( strtolower($coupon_code), WC()->cart->get_applied_coupons() );
    // Loop through cart items
    
    foreach ( WC()->cart->get_cart() as $cart_item ){
        if( has_term( $product_categories, 'product_cat', $cart_item['product_id'] ) && ! $coupon_applied ) {
            wc_clear_notices(); // Clear all other notices
            
            // Avoid checkout displaying an error notice
            wc_add_notice( sprintf( 'The product "%s" requires a valid redemption code for checkout.', $cart_item['data']->get_name() ), 'error' );
        
            break; // stop the loop
        }
    }
}

Edit:

Further to the comments and information from this link, I've tried the below code but this isn't working:

add_action( 'woocommerce_check_cart_items', 'mandatory_coupon_code' );
function mandatory_coupon_code() {
    $product_categories = array( 'gifts' ); // Category ID or slug of targeted category
    $coupon_code = array();
    
    foreach ( $coupons as $coupon ) {
        $coupon_name = $coupon->post_title;
        array_push( $coupon_code, $coupon_name );
    }
    
    $coupon_applied = in_array( strtolower($coupon_code), WC()->cart->get_applied_coupons() );
    
    // Loop through cart items
    foreach ( WC()->cart->get_cart() as $cart_item ){
        if( has_term( $product_categories, 'product_cat', $cart_item['product_id'] ) && ! $coupon_applied ) {
            wc_clear_notices(); // Clear all other notices
            // Avoid checkout displaying an error notice
            wc_add_notice( sprintf( 'The product "%s" requires a valid redemption code for checkout.', $cart_item['data']->get_name() ), 'error' );
            break; // stop the loop
        }
    }
}

Solution:

As wooCommerce already check for coupons validity when they are applied, If they are not valid it displays different warning messages depending on the reason for invalidity, removing invalid applied coupons??�

So you don't need to get all valid coupons in your code??� You just need the following:

add_action( 'woocommerce_check_cart_items', 'mandatory_redemption_coupon_code_for_gifted_items' );
function mandatory_redemption_coupon_code_for_gifted_items() {
    $product_categories = array( 'gifts' ); // Term ID, slug or name of targeted category

    $applied_coupons    = WC()->cart->get_applied_coupons();
    
    // When no coupon has been applied
    if( empty($applied_coupons) ) {
        // Loop through cart items
        foreach ( WC()->cart->get_cart() as $item ){
            // Check for gifted items
            if( has_term( $product_categories, 'product_cat', $item['product_id'] ) ) {
                wc_clear_notices(); // Clear all other notices
                
                // Avoid checkout displaying an error notice
                wc_add_notice( sprintf( 'The product "%s" requires a valid redemption code for checkout.', $item['data']->get_name() ), 'error' );
                break; // stop the loop
            }
        }
    }
}

Code goes in functions.php file of the active child theme (or active theme). Tested and works.

Now if the required coupons needs to be specific, you will have make a custom SQL query to check if any applied coupon is valid for redemption.

Note: on your Edit, the coupon query is missing, so that's why it doesn't work.