WooCommerce Hooks for Checkout, Cart, and Pricing

// 1. Catalog Pricing Overrides (Simple & Variable Products)
add_filter('woocommerce_product_get_price', 'ppunch_b2b_role_based_price', 10, 2);
add_filter('woocommerce_product_variation_get_price', 'ppunch_b2b_role_based_price', 10, 2);

function ppunch_b2b_role_based_price($price, $product) {
    if (is_admin() || !is_user_logged_in()) {
        return $price;
    }

    $user = wp_get_current_user();
    if (in_array('wholesale_customer', (array) $user->roles)) {
        // Apply a flat 20% discount for B2B wholesale buyers
        return floatval($price) * 0.8;
    }

    return $price;
}

// 2. Tiered Quantity Discounts inside Cart
add_action('woocommerce_before_calculate_totals', 'ppunch_apply_cart_quantity_tiers', 10, 1);

function ppunch_apply_cart_quantity_tiers($cart) {
    if (is_admin()) {
        return;
    }

    foreach ($cart->get_cart() as $cart_item_key => $cart_item) {
        $quantity = $cart_item['quantity'];
        $product = $cart_item['data'];
        $base_price = floatval($product->get_regular_price());

        // Apply bulk tiers: 10+ items get 10% off, 20+ items get 15% off
        if ($quantity >= 20) {
            $product->set_price($base_price * 0.85);
        } elseif ($quantity >= 10) {
            $product->set_price($base_price * 0.90);
        }
    }
}

// 1. Dynamic Low Order Fee Injection
add_action('woocommerce_cart_calculate_fees', 'ppunch_apply_low_order_fee', 10, 1);

function ppunch_apply_low_order_fee($cart) {
    if (is_admin()) {
        return;
    }

    $subtotal = floatval($cart->get_subtotal());
    
    // Apply a $5.00 fee for orders under $50
    if ($subtotal > 0 && $subtotal < 50.00) {
        $cart->add_fee('Low Order Handling Fee', 5.00, true, 'standard');
    }
}

// 1. Inject Custom Checkout Fields
add_filter('woocommerce_checkout_fields', 'ppunch_inject_corporate_checkout_fields', 10, 1);

function ppunch_inject_corporate_checkout_fields($fields) {

    $fields['billing']['billing_company_tax_id'] = [
        'type'        => 'text',
        'label'       => 'Company Tax ID / VAT Number',
        'placeholder' => 'Enter corporate registration number',
        'required'    => false,
        'class'       => ['form-row-wide'],
        'clear'       => true,
    ];

    return $fields;
}

// 2. Validate Custom Field Formatting
add_action('woocommerce_checkout_process', 'ppunch_validate_corporate_fields');

function ppunch_validate_corporate_fields() {

    // Require Tax ID if billing company is filled out
    if (!empty($_POST['billing_company']) && empty($_POST['billing_company_tax_id'])) {
        wc_add_notice('<strong>Company Tax ID / VAT Number</strong> is required for corporate orders.', 'error');
    }

    // Basic format validation (alphanumeric limit)
    if (!empty($_POST['billing_company_tax_id'])) {
        if (!preg_match('/^[A-Z0-9-]{4,15}$/i', $_POST['billing_company_tax_id'])) {
            wc_add_notice('Please enter a valid alphanumeric <strong>Company Tax ID / VAT Number</strong>.', 'error');
        }
    }
}

// 3. Save Custom Field directly to WooCommerce Order object
add_action('woocommerce_checkout_create_order', 'ppunch_save_corporate_fields_to_order', 10, 2);

function ppunch_save_corporate_fields_to_order($order, $data) {

    if (isset($_POST['billing_company_tax_id'])) {
        $tax_id = sanitize_text_field($_POST['billing_company_tax_id']);
        // Save using clean Order API wrapper method
        $order->update_meta_data('_billing_company_tax_id', $tax_id);
    }
}

// 1. Validate Item Compatibility before adding to Cart
add_filter('woocommerce_add_to_cart_validation', 'ppunch_restrict_mixed_cart_items', 10, 2);

function ppunch_restrict_mixed_cart_items($passed, $product_id) {

    $is_b2b_product = has_term('wholesale-only', 'product_cat', $product_id);

    foreach (WC()->cart->get_cart() as $cart_item) {
        $cart_product_id = $cart_item['product_id'];
        $cart_is_b2b = has_term('wholesale-only', 'product_cat', $cart_product_id);

        // Block mixing B2B wholesale items with regular retail items
        if ($is_b2b_product !== $cart_is_b2b) {
            wc_add_notice('Wholesale items cannot be mixed with standard retail items in the same checkout. Please submit separate orders.', 'error');
            return false;
        }
    }

    return $passed;
}

// 2. Safety scan during checkout page load
add_action('woocommerce_check_cart_items', 'ppunch_verify_cart_compatibility_on_checkout');

function ppunch_verify_cart_compatibility_on_checkout() {

    $has_wholesale = false;
    $has_retail = false;

    foreach (WC()->cart->get_cart() as $cart_item) {
        if (has_term('wholesale-only', 'product_cat', $cart_item['product_id'])) {
            $has_wholesale = true;
        } else {
            $has_retail = true;
        }
    }

    if ($has_wholesale && $has_retail) {
        wc_add_notice('Your cart contains both wholesale and retail items. Please split your order before proceeding to checkout.', 'error');
    }
}

// 1. Filter out shipping rates dynamically based on package weight
add_filter('woocommerce_package_rates', 'ppunch_filter_shipping_methods_by_weight', 10, 2);

function ppunch_filter_shipping_methods_by_weight($rates, $package) {

    // If total package weight is over 50 lbs, hide standard free shipping
    $total_weight = WC()->cart->get_cart_contents_weight();

    if ($total_weight > 50.00) {
        foreach ($rates as $rate_key => $rate) {
            // Remove Free Shipping option if it exists
            if ('free_shipping' === $rate->method_id) {
                unset($rates[$rate_key]);
            }
        }
    }

    return $rates;
}

// 1. Fire Webhook Sync on Successful Payment
add_action('woocommerce_payment_complete', 'ppunch_fire_non_blocking_checkout_webhook', 10, 1);

function ppunch_fire_non_blocking_checkout_webhook($order_id) {
    $order = wc_get_order($order_id);
    if (!$order) {
        return;
    }

    // Guard: Prevent duplicate webhook execution
    if ($order->get_meta('_ppunch_webhook_sent')) {
        return;
    }

    // Set flag immediately to prevent race conditions or multiple triggers
    $order->update_meta_data('_ppunch_webhook_sent', 'yes');
    $order->save();

    $webhook_url = 'https://api.yourcrm.com/v1/orders';
    $payload = [
        'order_id'      => $order_id,
        'order_total'   => $order->get_total(),
        'customer_email'=> $order->get_billing_email(),
        'items_count'   => $order->get_item_count(),
    ];

    wp_remote_post($webhook_url, [
        'method'    => 'POST',
        'blocking'  => false, // Essential: Does not wait for external response to keep checkout fast
        'body'      => json_encode($payload),
        'headers'   => [
            'Content-Type' => 'application/json',
        ],
        'timeout'   => 3,
    ]);
}