By Devport Team | Last updated: 2025-07-12 | 55 min read

WooCommerce Development: The Complete E-commerce Guide

WooCommerce powers over 28% of all online stores, making it the world's most popular e-commerce platform. Its flexibility, extensive ecosystem, and seamless WordPress integration make it the go-to choice for businesses of all sizes. This comprehensive guide covers everything from basic setup to advanced development techniques, helping you build powerful, scalable e-commerce solutions.

Whether you're creating a simple product catalog or a complex multi-vendor marketplace, understanding WooCommerce's architecture and capabilities is crucial for success. We'll explore custom product types, payment integrations, performance optimization, and advanced features that transform WooCommerce from a simple shopping cart into a complete e-commerce platform.

Table of Contents

  1. WooCommerce Architecture and Setup
  2. Product Management and Custom Types
  3. Payment Gateway Development
  4. Order Management and Fulfillment
  5. Performance Optimization
  6. Security and Compliance
  7. Advanced Features and Integrations

WooCommerce Architecture and Setup

Understanding WooCommerce Core

WooCommerce extends WordPress with comprehensive e-commerce functionality through a well-architected plugin system:

// WooCommerce core architecture overview
class WooCommerce_Architecture {

    /**
     * Core components initialization
     */
    public function __construct() {
        // Post types
        $this->register_post_types();

        // Taxonomies
        $this->register_taxonomies();

        // Database tables
        $this->create_tables();

        // Core classes
        $this->load_classes();

        // Hooks and filters
        $this->init_hooks();
    }

    private function register_post_types() {
        // Products
        register_post_type('product', [
            'labels' => [
                'name' => __('Products', 'woocommerce'),
                'singular_name' => __('Product', 'woocommerce'),
            ],
            'public' => true,
            'capability_type' => 'product',
            'map_meta_cap' => true,
            'supports' => ['title', 'editor', 'thumbnail', 'excerpt', 'custom-fields'],
            'has_archive' => true,
            'rewrite' => ['slug' => 'product'],
        ]);

        // Orders (Custom table-based in WC 3.0+)
        register_post_type('shop_order', [
            'labels' => [
                'name' => __('Orders', 'woocommerce'),
                'singular_name' => __('Order', 'woocommerce'),
            ],
            'public' => false,
            'show_ui' => true,
            'capability_type' => 'shop_order',
            'map_meta_cap' => true,
            'exclude_from_search' => true,
        ]);

        // Coupons
        register_post_type('shop_coupon', [
            'labels' => [
                'name' => __('Coupons', 'woocommerce'),
                'singular_name' => __('Coupon', 'woocommerce'),
            ],
            'public' => false,
            'show_ui' => true,
            'capability_type' => 'shop_coupon',
            'map_meta_cap' => true,
        ]);
    }

    private function register_taxonomies() {
        // Product categories
        register_taxonomy('product_cat', ['product'], [
            'hierarchical' => true,
            'labels' => [
                'name' => __('Categories', 'woocommerce'),
                'singular_name' => __('Category', 'woocommerce'),
            ],
            'rewrite' => ['slug' => 'product-category'],
        ]);

        // Product tags
        register_taxonomy('product_tag', ['product'], [
            'hierarchical' => false,
            'labels' => [
                'name' => __('Tags', 'woocommerce'),
                'singular_name' => __('Tag', 'woocommerce'),
            ],
            'rewrite' => ['slug' => 'product-tag'],
        ]);

        // Product attributes (dynamic)
        $this->register_attribute_taxonomies();
    }

    private function create_tables() {
        global $wpdb;

        $tables = [
            "{$wpdb->prefix}woocommerce_sessions",
            "{$wpdb->prefix}woocommerce_api_keys",
            "{$wpdb->prefix}woocommerce_attribute_taxonomies",
            "{$wpdb->prefix}woocommerce_downloadable_product_permissions",
            "{$wpdb->prefix}woocommerce_order_items",
            "{$wpdb->prefix}woocommerce_order_itemmeta",
            "{$wpdb->prefix}woocommerce_tax_rates",
            "{$wpdb->prefix}woocommerce_tax_rate_locations",
            "{$wpdb->prefix}woocommerce_shipping_zones",
            "{$wpdb->prefix}woocommerce_shipping_zone_locations",
            "{$wpdb->prefix}woocommerce_shipping_zone_methods",
            "{$wpdb->prefix}woocommerce_payment_tokens",
            "{$wpdb->prefix}woocommerce_payment_tokenmeta",
        ];

        // HPOS tables (High-Performance Order Storage)
        $tables[] = "{$wpdb->prefix}wc_orders";
        $tables[] = "{$wpdb->prefix}wc_order_addresses";
        $tables[] = "{$wpdb->prefix}wc_order_operational_data";
        $tables[] = "{$wpdb->prefix}wc_order_meta";

        return $tables;
    }
}

Advanced WooCommerce Setup

// Professional WooCommerce setup and configuration
class WooCommerce_Professional_Setup {

    /**
     * Initialize professional WooCommerce setup
     */
    public function __construct() {
        add_action('init', [$this, 'configure_woocommerce']);
        add_action('woocommerce_init', [$this, 'advanced_configuration']);
        add_filter('woocommerce_get_settings_pages', [$this, 'add_custom_settings']);
    }

    /**
     * Configure WooCommerce settings programmatically
     */
    public function configure_woocommerce() {
        // Enable HPOS (High-Performance Order Storage)
        update_option('woocommerce_feature_custom_order_tables_enabled', 'yes');
        update_option('woocommerce_custom_orders_table_enabled', 'yes');

        // Configure currency and pricing
        update_option('woocommerce_currency', 'USD');
        update_option('woocommerce_price_decimal_sep', '.');
        update_option('woocommerce_price_thousand_sep', ',');
        update_option('woocommerce_price_num_decimals', '2');

        // Tax configuration
        update_option('woocommerce_calc_taxes', 'yes');
        update_option('woocommerce_tax_based_on', 'shipping');
        update_option('woocommerce_tax_round_at_subtotal', 'yes');

        // Shipping configuration
        update_option('woocommerce_ship_to_countries', 'all');
        update_option('woocommerce_shipping_cost_requires_address', 'yes');
        update_option('woocommerce_shipping_debug_mode', 'no');

        // Checkout configuration
        update_option('woocommerce_enable_guest_checkout', 'yes');
        update_option('woocommerce_enable_checkout_login_reminder', 'yes');
        update_option('woocommerce_enable_signup_and_login_from_checkout', 'yes');

        // Security settings
        update_option('woocommerce_force_ssl_checkout', 'yes');
        update_option('woocommerce_unforce_ssl_checkout', 'no');
    }

    /**
     * Advanced configuration and optimizations
     */
    public function advanced_configuration() {
        // Configure image sizes
        add_image_size('woocommerce_thumbnail', 300, 300, true);
        add_image_size('woocommerce_single', 600, 600, true);
        add_image_size('woocommerce_gallery_thumbnail', 100, 100, true);

        // Configure product data tabs
        add_filter('woocommerce_product_data_tabs', [$this, 'add_custom_product_tabs']);

        // Configure checkout fields
        add_filter('woocommerce_checkout_fields', [$this, 'customize_checkout_fields']);

        // Configure email settings
        add_filter('woocommerce_email_classes', [$this, 'add_custom_email_classes']);

        // Performance optimizations
        $this->configure_performance_settings();
    }

    /**
     * Configure performance settings
     */
    private function configure_performance_settings() {
        // Limit cart session expiry
        add_filter('wc_session_expiring', function() {
            return 47 * HOUR_IN_SECONDS;
        });

        add_filter('wc_session_expiration', function() {
            return 48 * HOUR_IN_SECONDS;
        });

        // Configure AJAX settings
        add_filter('woocommerce_ajax_variation_threshold', function() {
            return 100; // Limit AJAX variations
        });

        // Configure database queries
        add_filter('woocommerce_product_query_meta_query', [$this, 'optimize_product_queries']);
        add_filter('woocommerce_order_query_args', [$this, 'optimize_order_queries']);

        // Configure caching
        $this->setup_caching_rules();
    }

    /**
     * Setup caching rules for WooCommerce
     */
    private function setup_caching_rules() {
        // Exclude WooCommerce pages from cache
        if (function_exists('wp_cache_add_non_persistent_groups')) {
            wp_cache_add_non_persistent_groups(['wc_session_id']);
        }

        // Define dynamic pages
        $dynamic_pages = [
            wc_get_page_id('cart'),
            wc_get_page_id('checkout'),
            wc_get_page_id('myaccount'),
        ];

        // Add cache exclusion rules
        foreach ($dynamic_pages as $page_id) {
            if ($page_id > 0) {
                add_action('wp', function() use ($page_id) {
                    if (is_page($page_id)) {
                        nocache_headers();
                    }
                });
            }
        }
    }
}

// Initialize professional setup
new WooCommerce_Professional_Setup();

WooCommerce Database Structure

// Understanding WooCommerce database architecture
class WooCommerce_Database_Structure {

    /**
     * Document core database relationships
     */
    public function get_database_schema() {
        global $wpdb;

        return [
            'products' => [
                'table' => $wpdb->posts,
                'meta_table' => $wpdb->postmeta,
                'relationships' => [
                    'categories' => $wpdb->term_relationships,
                    'attributes' => $wpdb->prefix . 'woocommerce_attribute_taxonomies',
                    'variations' => $wpdb->posts . ' (post_parent relationship)',
                ],
                'key_meta' => [
                    '_price',
                    '_regular_price',
                    '_sale_price',
                    '_sku',
                    '_stock',
                    '_stock_status',
                    '_visibility',
                    '_featured',
                    '_virtual',
                    '_downloadable',
                    '_weight',
                    '_length',
                    '_width',
                    '_height',
                ],
            ],

            'orders' => [
                'table' => $wpdb->prefix . 'wc_orders', // HPOS
                'legacy_table' => $wpdb->posts,
                'meta_table' => $wpdb->prefix . 'wc_order_meta',
                'items_table' => $wpdb->prefix . 'woocommerce_order_items',
                'itemmeta_table' => $wpdb->prefix . 'woocommerce_order_itemmeta',
                'relationships' => [
                    'customer' => $wpdb->prefix . 'wc_customer_lookup',
                    'addresses' => $wpdb->prefix . 'wc_order_addresses',
                    'operational_data' => $wpdb->prefix . 'wc_order_operational_data',
                ],
            ],

            'customers' => [
                'table' => $wpdb->users,
                'meta_table' => $wpdb->usermeta,
                'lookup_table' => $wpdb->prefix . 'wc_customer_lookup',
                'key_meta' => [
                    'billing_first_name',
                    'billing_last_name',
                    'billing_company',
                    'billing_address_1',
                    'billing_address_2',
                    'billing_city',
                    'billing_state',
                    'billing_postcode',
                    'billing_country',
                    'billing_email',
                    'billing_phone',
                    'shipping_first_name',
                    'shipping_last_name',
                    'shipping_company',
                    'shipping_address_1',
                    'shipping_address_2',
                    'shipping_city',
                    'shipping_state',
                    'shipping_postcode',
                    'shipping_country',
                ],
            ],

            'analytics' => [
                'orders_stats' => $wpdb->prefix . 'wc_order_stats',
                'products_lookup' => $wpdb->prefix . 'wc_product_lookup',
                'customers_lookup' => $wpdb->prefix . 'wc_customer_lookup',
                'categories_lookup' => $wpdb->prefix . 'wc_category_lookup',
            ],
        ];
    }

    /**
     * Optimize database queries
     */
    public function optimize_database() {
        global $wpdb;

        // Add indexes for better performance
        $indexes = [
            [
                'table' => $wpdb->postmeta,
                'name' => 'idx_meta_key_value',
                'columns' => 'meta_key(191), meta_value(100)',
            ],
            [
                'table' => $wpdb->prefix . 'woocommerce_order_items',
                'name' => 'idx_order_item_type',
                'columns' => 'order_id, order_item_type',
            ],
            [
                'table' => $wpdb->prefix . 'wc_order_stats',
                'name' => 'idx_status_date',
                'columns' => 'status(191), date_created',
            ],
        ];

        foreach ($indexes as $index) {
            $this->create_index($index['table'], $index['name'], $index['columns']);
        }
    }

    /**
     * Create database index if not exists
     */
    private function create_index($table, $index_name, $columns) {
        global $wpdb;

        $index_exists = $wpdb->get_var($wpdb->prepare(
            "SELECT COUNT(1) FROM INFORMATION_SCHEMA.STATISTICS 
             WHERE table_schema = %s 
             AND table_name = %s 
             AND index_name = %s",
            DB_NAME,
            $table,
            $index_name
        ));

        if (!$index_exists) {
            $wpdb->query("CREATE INDEX $index_name ON $table ($columns)");
        }
    }
}

Product Management and Custom Types

Creating Custom Product Types

// Advanced custom product type implementation
class WC_Product_Custom_Type extends WC_Product {

    /**
     * Product type name
     */
    protected $product_type = 'custom_type';

    /**
     * Constructor
     */
    public function __construct($product = 0) {
        parent::__construct($product);
    }

    /**
     * Get product type
     */
    public function get_type() {
        return 'custom_type';
    }

    /**
     * Product type specific functionality
     */
    public function add_to_cart_url() {
        $url = $this->is_purchasable() && $this->is_in_stock() 
            ? remove_query_arg('added-to-cart', add_query_arg('add-to-cart', $this->get_id())) 
            : get_permalink($this->get_id());

        return apply_filters('woocommerce_product_add_to_cart_url', $url, $this);
    }

    /**
     * Get add to cart button text
     */
    public function add_to_cart_text() {
        $text = $this->is_purchasable() && $this->is_in_stock() 
            ? __('Add to cart', 'woocommerce') 
            : __('Read more', 'woocommerce');

        return apply_filters('woocommerce_product_add_to_cart_text', $text, $this);
    }

    /**
     * Check if product can be purchased
     */
    public function is_purchasable() {
        return apply_filters('woocommerce_is_purchasable', true, $this);
    }

    /**
     * Custom validation for this product type
     */
    public function validate_add_to_cart($quantity = 1) {
        $validation = true;

        // Custom validation logic
        if ($this->get_meta('_requires_approval') === 'yes') {
            if (!current_user_can('purchase_restricted_products')) {
                wc_add_notice(__('This product requires approval to purchase.', 'woocommerce'), 'error');
                $validation = false;
            }
        }

        // Check custom limits
        $max_quantity = $this->get_meta('_max_quantity_per_order');
        if ($max_quantity && $quantity > $max_quantity) {
            wc_add_notice(
                sprintf(
                    __('Maximum quantity per order is %d.', 'woocommerce'),
                    $max_quantity
                ),
                'error'
            );
            $validation = false;
        }

        return apply_filters('woocommerce_add_to_cart_validation', $validation, $this->get_id(), $quantity);
    }
}

// Register custom product type
class WC_Custom_Product_Type_Manager {

    public function __construct() {
        add_filter('product_type_selector', [$this, 'add_product_type']);
        add_filter('woocommerce_product_class', [$this, 'load_product_class'], 10, 2);
        add_action('admin_footer', [$this, 'add_product_type_options']);
        add_action('woocommerce_process_product_meta_custom_type', [$this, 'save_product_data']);

        // Add custom tabs
        add_filter('woocommerce_product_data_tabs', [$this, 'add_product_tabs']);
        add_action('woocommerce_product_data_panels', [$this, 'add_product_panels']);
    }

    /**
     * Add custom product type to selector
     */
    public function add_product_type($types) {
        $types['custom_type'] = __('Custom Product Type', 'woocommerce');
        return $types;
    }

    /**
     * Load custom product class
     */
    public function load_product_class($classname, $product_type) {
        if ($product_type === 'custom_type') {
            $classname = 'WC_Product_Custom_Type';
        }
        return $classname;
    }

    /**
     * Add custom product options
     */
    public function add_product_type_options() {
        if ('product' !== get_post_type()) {
            return;
        }
        ?>
        <script type='text/javascript'>
            jQuery(document).ready(function($) {
                // Add custom options
                $('.options_group.pricing').addClass('show_if_custom_type');

                // Custom type specific options
                jQuery('.product_data_tabs .general_tab').addClass('show_if_custom_type');
                jQuery('#general_product_data .pricing').addClass('show_if_custom_type');

                // Show/hide on load
                if ($('#product-type').val() === 'custom_type') {
                    $('.show_if_custom_type').show();
                }

                // Show/hide on change
                $('#product-type').on('change', function() {
                    if ($(this).val() === 'custom_type') {
                        $('.show_if_custom_type').show();
                    }
                });
            });
        </script>
        <?php
    }

    /**
     * Add custom product data tabs
     */
    public function add_product_tabs($tabs) {
        $tabs['custom_options'] = [
            'label' => __('Custom Options', 'woocommerce'),
            'target' => 'custom_options_data',
            'class' => ['show_if_custom_type'],
            'priority' => 21,
        ];

        return $tabs;
    }

    /**
     * Add custom product data panels
     */
    public function add_product_panels() {
        global $post;
        ?>
        <div id='custom_options_data' class='panel woocommerce_options_panel'>
            <div class='options_group'>
                <?php
                woocommerce_wp_checkbox([
                    'id' => '_requires_approval',
                    'label' => __('Requires Approval', 'woocommerce'),
                    'description' => __('Check this box if the product requires approval before purchase.', 'woocommerce'),
                ]);

                woocommerce_wp_text_input([
                    'id' => '_max_quantity_per_order',
                    'label' => __('Max Quantity per Order', 'woocommerce'),
                    'type' => 'number',
                    'custom_attributes' => [
                        'step' => '1',
                        'min' => '1',
                    ],
                ]);

                woocommerce_wp_textarea_input([
                    'id' => '_custom_product_message',
                    'label' => __('Custom Product Message', 'woocommerce'),
                    'placeholder' => __('Enter a custom message for this product type', 'woocommerce'),
                    'desc_tip' => true,
                    'description' => __('This message will be displayed on the product page.', 'woocommerce'),
                ]);
                ?>
            </div>
        </div>
        <?php
    }

    /**
     * Save custom product data
     */
    public function save_product_data($post_id) {
        $requires_approval = isset($_POST['_requires_approval']) ? 'yes' : 'no';
        update_post_meta($post_id, '_requires_approval', $requires_approval);

        if (isset($_POST['_max_quantity_per_order'])) {
            update_post_meta($post_id, '_max_quantity_per_order', absint($_POST['_max_quantity_per_order']));
        }

        if (isset($_POST['_custom_product_message'])) {
            update_post_meta($post_id, '_custom_product_message', sanitize_textarea_field($_POST['_custom_product_message']));
        }
    }
}

// Initialize custom product type
new WC_Custom_Product_Type_Manager();

Advanced Product Variations

// Advanced product variation management
class WC_Advanced_Variations_Manager {

    /**
     * Initialize advanced variations
     */
    public function __construct() {
        // Bulk variation creation
        add_action('woocommerce_variable_product_bulk_actions', [$this, 'add_bulk_actions']);
        add_action('woocommerce_bulk_edit_variations', [$this, 'bulk_edit_variations'], 10, 4);

        // Custom variation fields
        add_action('woocommerce_product_after_variable_attributes', [$this, 'add_custom_variation_fields'], 10, 3);
        add_action('woocommerce_save_product_variation', [$this, 'save_custom_variation_fields'], 10, 2);

        // Variation display customization
        add_filter('woocommerce_available_variation', [$this, 'modify_available_variation'], 10, 3);

        // AJAX handlers
        add_action('wp_ajax_create_all_variations', [$this, 'ajax_create_all_variations']);
    }

    /**
     * Add bulk variation actions
     */
    public function add_bulk_actions() {
        ?>
        <option value="create_all_variations"><?php esc_html_e('Create all variations', 'woocommerce'); ?></option>
        <option value="set_regular_price_increase"><?php esc_html_e('Increase regular price by percentage', 'woocommerce'); ?></option>
        <option value="set_sale_price_decrease"><?php esc_html_e('Decrease sale price by percentage', 'woocommerce'); ?></option>
        <?php
    }

    /**
     * Handle bulk edit variations
     */
    public function bulk_edit_variations($bulk_action, $data, $product_id, $variations) {
        switch ($bulk_action) {
            case 'create_all_variations':
                $this->create_all_possible_variations($product_id);
                break;

            case 'set_regular_price_increase':
                if (isset($data['value'])) {
                    $this->adjust_variation_prices($variations, 'regular', $data['value'], 'increase');
                }
                break;

            case 'set_sale_price_decrease':
                if (isset($data['value'])) {
                    $this->adjust_variation_prices($variations, 'sale', $data['value'], 'decrease');
                }
                break;
        }
    }

    /**
     * Create all possible variations
     */
    private function create_all_possible_variations($product_id) {
        $product = wc_get_product($product_id);

        if (!$product || !$product->is_type('variable')) {
            return false;
        }

        $attributes = $product->get_variation_attributes();
        $possible_variations = $this->generate_variation_combinations($attributes);
        $existing_variations = $product->get_children();

        foreach ($possible_variations as $variation_attributes) {
            // Check if variation already exists
            if ($this->variation_exists($product_id, $variation_attributes, $existing_variations)) {
                continue;
            }

            // Create new variation
            $variation = new WC_Product_Variation();
            $variation->set_parent_id($product_id);
            $variation->set_attributes($variation_attributes);

            // Set default data
            $variation->set_regular_price($product->get_regular_price());
            $variation->set_manage_stock(false);
            $variation->set_status('publish');

            // Save variation
            $variation->save();
        }

        // Clear caches
        WC_Cache_Helper::get_transient_version('product', true);
    }

    /**
     * Generate all possible variation combinations
     */
    private function generate_variation_combinations($attributes) {
        $combinations = [[]];

        foreach ($attributes as $attribute => $values) {
            $new_combinations = [];

            foreach ($combinations as $combination) {
                foreach ($values as $value) {
                    $new_combination = $combination;
                    $new_combination[$attribute] = $value;
                    $new_combinations[] = $new_combination;
                }
            }

            $combinations = $new_combinations;
        }

        return $combinations;
    }

    /**
     * Check if variation exists
     */
    private function variation_exists($product_id, $attributes, $existing_variations) {
        foreach ($existing_variations as $variation_id) {
            $variation = wc_get_product($variation_id);

            if (!$variation) {
                continue;
            }

            $variation_attributes = $variation->get_variation_attributes();

            if ($this->attributes_match($attributes, $variation_attributes)) {
                return true;
            }
        }

        return false;
    }

    /**
     * Add custom variation fields
     */
    public function add_custom_variation_fields($loop, $variation_data, $variation) {
        $variation_object = wc_get_product($variation->ID);
        ?>
        <div class="custom-variation-fields">
            <p class="form-row form-row-full">
                <label><?php esc_html_e('Delivery Time (days)', 'woocommerce'); ?></label>
                <input type="number" 
                       name="variable_delivery_time[<?php echo esc_attr($loop); ?>]" 
                       value="<?php echo esc_attr($variation_object->get_meta('_delivery_time')); ?>" 
                       placeholder="<?php esc_attr_e('e.g., 3-5', 'woocommerce'); ?>" />
            </p>

            <p class="form-row form-row-full">
                <label><?php esc_html_e('Minimum Order Quantity', 'woocommerce'); ?></label>
                <input type="number" 
                       name="variable_min_quantity[<?php echo esc_attr($loop); ?>]" 
                       value="<?php echo esc_attr($variation_object->get_meta('_min_quantity')); ?>" 
                       min="1" 
                       step="1" />
            </p>

            <p class="form-row form-row-full">
                <label>
                    <input type="checkbox" 
                           name="variable_is_preorder[<?php echo esc_attr($loop); ?>]" 
                           value="yes" 
                           <?php checked($variation_object->get_meta('_is_preorder'), 'yes'); ?> />
                    <?php esc_html_e('This is a pre-order product', 'woocommerce'); ?>
                </label>
            </p>
        </div>
        <?php
    }

    /**
     * Save custom variation fields
     */
    public function save_custom_variation_fields($variation_id, $loop) {
        if (isset($_POST['variable_delivery_time'][$loop])) {
            update_post_meta($variation_id, '_delivery_time', sanitize_text_field($_POST['variable_delivery_time'][$loop]));
        }

        if (isset($_POST['variable_min_quantity'][$loop])) {
            update_post_meta($variation_id, '_min_quantity', absint($_POST['variable_min_quantity'][$loop]));
        }

        $is_preorder = isset($_POST['variable_is_preorder'][$loop]) ? 'yes' : 'no';
        update_post_meta($variation_id, '_is_preorder', $is_preorder);
    }

    /**
     * Modify available variation data
     */
    public function modify_available_variation($data, $product, $variation) {
        $data['delivery_time'] = $variation->get_meta('_delivery_time');
        $data['min_quantity'] = $variation->get_meta('_min_quantity') ?: 1;
        $data['is_preorder'] = $variation->get_meta('_is_preorder') === 'yes';

        // Add custom price display
        if ($data['is_preorder']) {
            $data['price_html'] = '<span class="preorder-price">' . $data['price_html'] . '</span>';
            $data['availability_html'] .= '<p class="preorder-notice">' . __('This is a pre-order item', 'woocommerce') . '</p>';
        }

        return $data;
    }
}

// Initialize advanced variations
new WC_Advanced_Variations_Manager();

Product Data Import/Export

// Advanced product import/export functionality
class WC_Advanced_Product_Importer {

    /**
     * Initialize importer
     */
    public function __construct() {
        add_filter('woocommerce_csv_product_import_mapping_options', [$this, 'add_custom_import_columns']);
        add_filter('woocommerce_csv_product_import_mapping_default_columns', [$this, 'add_column_mappings']);
        add_filter('woocommerce_product_importer_parsed_data', [$this, 'parse_custom_data'], 10, 2);
        add_filter('woocommerce_product_import_inserted_product_object', [$this, 'process_custom_data'], 10, 2);

        // Export functionality
        add_filter('woocommerce_product_export_column_names', [$this, 'add_export_columns']);
        add_filter('woocommerce_product_export_product_default_columns', [$this, 'add_export_column_mappings']);
        add_filter('woocommerce_product_export_product_column_custom_field', [$this, 'export_custom_field'], 10, 3);
    }

    /**
     * Add custom import columns
     */
    public function add_custom_import_columns($columns) {
        $columns['supplier_sku'] = __('Supplier SKU', 'woocommerce');
        $columns['warehouse_location'] = __('Warehouse Location', 'woocommerce');
        $columns['reorder_level'] = __('Reorder Level', 'woocommerce');
        $columns['lead_time'] = __('Lead Time (days)', 'woocommerce');
        $columns['country_of_origin'] = __('Country of Origin', 'woocommerce');
        $columns['hs_code'] = __('HS Code', 'woocommerce');

        return $columns;
    }

    /**
     * Process imported custom data
     */
    public function process_custom_data($product, $data) {
        // Process supplier information
        if (!empty($data['supplier_sku'])) {
            $product->update_meta_data('_supplier_sku', sanitize_text_field($data['supplier_sku']));
        }

        if (!empty($data['warehouse_location'])) {
            $product->update_meta_data('_warehouse_location', sanitize_text_field($data['warehouse_location']));
        }

        // Process inventory management
        if (!empty($data['reorder_level'])) {
            $product->update_meta_data('_reorder_level', absint($data['reorder_level']));

            // Check if automatic reorder needed
            if ($product->get_stock_quantity() <= absint($data['reorder_level'])) {
                $this->trigger_reorder_notification($product);
            }
        }

        if (!empty($data['lead_time'])) {
            $product->update_meta_data('_lead_time', absint($data['lead_time']));
        }

        // Process shipping information
        if (!empty($data['country_of_origin'])) {
            $product->update_meta_data('_country_of_origin', sanitize_text_field($data['country_of_origin']));
        }

        if (!empty($data['hs_code'])) {
            $product->update_meta_data('_hs_code', sanitize_text_field($data['hs_code']));
        }

        return $product;
    }

    /**
     * Trigger reorder notification
     */
    private function trigger_reorder_notification($product) {
        $mailer = WC()->mailer();
        $recipient = get_option('woocommerce_stock_email_recipient', get_option('admin_email'));

        $subject = sprintf(
            __('Reorder needed for %s', 'woocommerce'),
            $product->get_name()
        );

        $message = sprintf(
            __('The stock level for %s (SKU: %s) has fallen below the reorder level.', 'woocommerce'),
            $product->get_name(),
            $product->get_sku()
        );

        $message .= "\n\n" . sprintf(
            __('Current Stock: %d', 'woocommerce'),
            $product->get_stock_quantity()
        );

        $message .= "\n" . sprintf(
            __('Reorder Level: %d', 'woocommerce'),
            $product->get_meta('_reorder_level')
        );

        $mailer->send($recipient, $subject, $message);
    }
}

// Initialize importer
new WC_Advanced_Product_Importer();
```## Payment Gateway Development {#payment-gateways}

### Creating Custom Payment Gateways

```php
// Custom payment gateway implementation
class WC_Gateway_Custom extends WC_Payment_Gateway {

    /**
     * Constructor
     */
    public function __construct() {
        $this->id = 'custom_gateway';
        $this->icon = apply_filters('woocommerce_custom_gateway_icon', '');
        $this->has_fields = true;
        $this->method_title = __('Custom Payment Gateway', 'woocommerce');
        $this->method_description = __('Accept payments through custom payment gateway', 'woocommerce');

        // Load settings
        $this->init_form_fields();
        $this->init_settings();

        // Define user settings
        $this->title = $this->get_option('title');
        $this->description = $this->get_option('description');
        $this->enabled = $this->get_option('enabled');
        $this->testmode = 'yes' === $this->get_option('testmode');
        $this->api_key = $this->testmode ? $this->get_option('test_api_key') : $this->get_option('live_api_key');
        $this->api_secret = $this->testmode ? $this->get_option('test_api_secret') : $this->get_option('live_api_secret');

        // Hooks
        add_action('woocommerce_update_options_payment_gateways_' . $this->id, [$this, 'process_admin_options']);
        add_action('woocommerce_receipt_' . $this->id, [$this, 'receipt_page']);
        add_action('woocommerce_api_wc_gateway_custom', [$this, 'webhook_handler']);

        // Enqueue scripts
        add_action('wp_enqueue_scripts', [$this, 'payment_scripts']);
    }

    /**
     * Initialize gateway settings form fields
     */
    public function init_form_fields() {
        $this->form_fields = [
            'enabled' => [
                'title' => __('Enable/Disable', 'woocommerce'),
                'type' => 'checkbox',
                'label' => __('Enable Custom Payment Gateway', 'woocommerce'),
                'default' => 'yes',
            ],
            'title' => [
                'title' => __('Title', 'woocommerce'),
                'type' => 'text',
                'description' => __('This controls the title which the user sees during checkout.', 'woocommerce'),
                'default' => __('Custom Payment', 'woocommerce'),
                'desc_tip' => true,
            ],
            'description' => [
                'title' => __('Description', 'woocommerce'),
                'type' => 'textarea',
                'description' => __('Payment method description that the customer will see on your checkout.', 'woocommerce'),
                'default' => __('Pay securely using our custom payment gateway.', 'woocommerce'),
            ],
            'testmode' => [
                'title' => __('Test mode', 'woocommerce'),
                'type' => 'checkbox',
                'label' => __('Enable Test Mode', 'woocommerce'),
                'default' => 'yes',
                'description' => __('Place the payment gateway in test mode using test API keys.', 'woocommerce'),
            ],
            'test_api_key' => [
                'title' => __('Test API Key', 'woocommerce'),
                'type' => 'text',
            ],
            'test_api_secret' => [
                'title' => __('Test API Secret', 'woocommerce'),
                'type' => 'password',
            ],
            'live_api_key' => [
                'title' => __('Live API Key', 'woocommerce'),
                'type' => 'text',
            ],
            'live_api_secret' => [
                'title' => __('Live API Secret', 'woocommerce'),
                'type' => 'password',
            ],
            'webhook_secret' => [
                'title' => __('Webhook Secret', 'woocommerce'),
                'type' => 'password',
                'description' => __('Enter the webhook secret key provided by the payment gateway.', 'woocommerce'),
            ],
        ];
    }

    /**
     * Payment form on checkout page
     */
    public function payment_fields() {
        if ($this->description) {
            echo wpautop(wp_kses_post($this->description));
        }

        if ($this->testmode) {
            echo '<p>' . __('TEST MODE ENABLED. Use test card numbers.', 'woocommerce') . '</p>';
        }

        ?>
        <fieldset id="wc-<?php echo esc_attr($this->id); ?>-cc-form" class="wc-credit-card-form wc-payment-form">
            <?php do_action('woocommerce_credit_card_form_start', $this->id); ?>

            <p class="form-row form-row-wide">
                <label for="<?php echo esc_attr($this->id); ?>-card-number">
                    <?php esc_html_e('Card Number', 'woocommerce'); ?> <span class="required">*</span>
                </label>
                <input id="<?php echo esc_attr($this->id); ?>-card-number" 
                       class="input-text wc-credit-card-form-card-number" 
                       inputmode="numeric" 
                       autocomplete="cc-number" 
                       autocorrect="no" 
                       autocapitalize="no" 
                       spellcheck="no" 
                       type="tel" 
                       placeholder="&bull;&bull;&bull;&bull; &bull;&bull;&bull;&bull; &bull;&bull;&bull;&bull; &bull;&bull;&bull;&bull;" />
            </p>

            <p class="form-row form-row-first">
                <label for="<?php echo esc_attr($this->id); ?>-card-expiry">
                    <?php esc_html_e('Expiry (MM/YY)', 'woocommerce'); ?> <span class="required">*</span>
                </label>
                <input id="<?php echo esc_attr($this->id); ?>-card-expiry" 
                       class="input-text wc-credit-card-form-card-expiry" 
                       inputmode="numeric" 
                       autocomplete="cc-exp" 
                       autocorrect="no" 
                       autocapitalize="no" 
                       spellcheck="no" 
                       type="tel" 
                       placeholder="<?php esc_attr_e('MM / YY', 'woocommerce'); ?>" />
            </p>

            <p class="form-row form-row-last">
                <label for="<?php echo esc_attr($this->id); ?>-card-cvc">
                    <?php esc_html_e('Card Code', 'woocommerce'); ?> <span class="required">*</span>
                </label>
                <input id="<?php echo esc_attr($this->id); ?>-card-cvc" 
                       class="input-text wc-credit-card-form-card-cvc" 
                       inputmode="numeric" 
                       autocomplete="off" 
                       autocorrect="no" 
                       autocapitalize="no" 
                       spellcheck="no" 
                       type="tel" 
                       maxlength="4" 
                       placeholder="<?php esc_attr_e('CVC', 'woocommerce'); ?>" />
            </p>

            <?php do_action('woocommerce_credit_card_form_end', $this->id); ?>

            <div class="clear"></div>
        </fieldset>
        <?php
    }

    /**
     * Process the payment
     */
    public function process_payment($order_id) {
        $order = wc_get_order($order_id);

        try {
            // Validate payment fields
            $this->validate_fields();

            // Create payment intent
            $payment_intent = $this->create_payment_intent($order);

            if ($payment_intent['status'] === 'requires_action') {
                // 3D Secure or additional authentication required
                return [
                    'result' => 'success',
                    'redirect' => $order->get_checkout_payment_url(true),
                    'payment_intent' => $payment_intent['client_secret'],
                ];
            } elseif ($payment_intent['status'] === 'succeeded') {
                // Payment successful
                $order->payment_complete($payment_intent['id']);
                $order->add_order_note(
                    sprintf(
                        __('Payment completed via %s (Transaction ID: %s)', 'woocommerce'),
                        $this->method_title,
                        $payment_intent['id']
                    )
                );

                // Clear cart
                WC()->cart->empty_cart();

                return [
                    'result' => 'success',
                    'redirect' => $this->get_return_url($order),
                ];
            } else {
                throw new Exception(__('Payment failed. Please try again.', 'woocommerce'));
            }

        } catch (Exception $e) {
            wc_add_notice($e->getMessage(), 'error');
            return [
                'result' => 'fail',
                'redirect' => '',
            ];
        }
    }

    /**
     * Create payment intent
     */
    private function create_payment_intent($order) {
        $endpoint = $this->testmode 
            ? 'https://api.sandbox.payment-gateway.com/v1/payment-intents' 
            : 'https://api.payment-gateway.com/v1/payment-intents';

        $request_data = [
            'amount' => $order->get_total() * 100, // Convert to cents
            'currency' => strtolower($order->get_currency()),
            'description' => sprintf(
                __('Order %s from %s', 'woocommerce'),
                $order->get_order_number(),
                get_bloginfo('name')
            ),
            'metadata' => [
                'order_id' => $order->get_id(),
                'order_key' => $order->get_order_key(),
                'customer_email' => $order->get_billing_email(),
            ],
            'capture_method' => 'automatic',
            'confirm' => true,
            'payment_method_data' => [
                'type' => 'card',
                'card' => [
                    'number' => $this->get_post_data('custom_gateway-card-number'),
                    'exp_month' => $this->get_card_expiry_month(),
                    'exp_year' => $this->get_card_expiry_year(),
                    'cvc' => $this->get_post_data('custom_gateway-card-cvc'),
                ],
                'billing_details' => [
                    'name' => $order->get_formatted_billing_full_name(),
                    'email' => $order->get_billing_email(),
                    'phone' => $order->get_billing_phone(),
                    'address' => [
                        'line1' => $order->get_billing_address_1(),
                        'line2' => $order->get_billing_address_2(),
                        'city' => $order->get_billing_city(),
                        'state' => $order->get_billing_state(),
                        'postal_code' => $order->get_billing_postcode(),
                        'country' => $order->get_billing_country(),
                    ],
                ],
            ],
        ];

        $response = wp_remote_post($endpoint, [
            'method' => 'POST',
            'headers' => [
                'Authorization' => 'Bearer ' . $this->api_key,
                'Content-Type' => 'application/json',
            ],
            'body' => wp_json_encode($request_data),
            'timeout' => 45,
        ]);

        if (is_wp_error($response)) {
            throw new Exception(__('Connection error. Please try again.', 'woocommerce'));
        }

        $response_body = json_decode(wp_remote_retrieve_body($response), true);

        if (empty($response_body['id'])) {
            $error_message = isset($response_body['error']['message']) 
                ? $response_body['error']['message'] 
                : __('An error occurred processing your payment.', 'woocommerce');
            throw new Exception($error_message);
        }

        return $response_body;
    }

    /**
     * Webhook handler
     */
    public function webhook_handler() {
        $payload = file_get_contents('php://input');
        $sig_header = $_SERVER['HTTP_WEBHOOK_SIGNATURE'] ?? '';

        try {
            $event = $this->verify_webhook_signature($payload, $sig_header);

            switch ($event['type']) {
                case 'payment_intent.succeeded':
                    $this->handle_payment_success($event['data']['object']);
                    break;

                case 'payment_intent.payment_failed':
                    $this->handle_payment_failure($event['data']['object']);
                    break;

                case 'charge.dispute.created':
                    $this->handle_dispute($event['data']['object']);
                    break;
            }

            status_header(200);
            exit;

        } catch (Exception $e) {
            status_header(400);
            exit($e->getMessage());
        }
    }

    /**
     * Verify webhook signature
     */
    private function verify_webhook_signature($payload, $sig_header) {
        $webhook_secret = $this->get_option('webhook_secret');

        if (empty($webhook_secret)) {
            throw new Exception('Webhook secret not configured');
        }

        $expected_sig = hash_hmac('sha256', $payload, $webhook_secret);

        if (!hash_equals($expected_sig, $sig_header)) {
            throw new Exception('Invalid signature');
        }

        return json_decode($payload, true);
    }
}

// Register gateway
add_filter('woocommerce_payment_gateways', function($gateways) {
    $gateways[] = 'WC_Gateway_Custom';
    return $gateways;
});

Payment Gateway Security

// Advanced payment security implementation
class WC_Payment_Security_Manager {

    /**
     * Initialize security features
     */
    public function __construct() {
        // PCI compliance
        add_action('wp_enqueue_scripts', [$this, 'enqueue_security_scripts']);
        add_filter('woocommerce_checkout_fields', [$this, 'add_security_fields']);

        // Fraud detection
        add_action('woocommerce_checkout_process', [$this, 'fraud_detection']);
        add_filter('woocommerce_payment_complete_order_status', [$this, 'hold_suspicious_orders'], 10, 3);

        // Tokenization
        add_action('woocommerce_payment_token_set_default', [$this, 'secure_token_storage']);

        // Rate limiting
        add_action('woocommerce_before_checkout_process', [$this, 'rate_limit_checkout']);
    }

    /**
     * Implement fraud detection
     */
    public function fraud_detection() {
        $fraud_score = 0;
        $fraud_reasons = [];

        // Check IP reputation
        $ip_score = $this->check_ip_reputation(WC_Geolocation::get_ip_address());
        if ($ip_score > 50) {
            $fraud_score += $ip_score;
            $fraud_reasons[] = 'Suspicious IP address';
        }

        // Check email domain
        $email = $_POST['billing_email'] ?? '';
        if ($this->is_disposable_email($email)) {
            $fraud_score += 30;
            $fraud_reasons[] = 'Disposable email address';
        }

        // Check velocity (multiple orders in short time)
        $velocity_score = $this->check_order_velocity($email);
        if ($velocity_score > 0) {
            $fraud_score += $velocity_score;
            $fraud_reasons[] = 'High order velocity';
        }

        // Check address verification
        if (!$this->verify_address($_POST)) {
            $fraud_score += 20;
            $fraud_reasons[] = 'Address verification failed';
        }

        // Device fingerprinting
        $device_score = $this->check_device_fingerprint();
        if ($device_score > 0) {
            $fraud_score += $device_score;
            $fraud_reasons[] = 'Suspicious device';
        }

        // Store fraud score for payment gateway
        WC()->session->set('fraud_score', $fraud_score);
        WC()->session->set('fraud_reasons', $fraud_reasons);

        // Block high-risk transactions
        if ($fraud_score >= 80) {
            wc_add_notice(
                __('Your transaction has been flagged for security review. Please contact support.', 'woocommerce'),
                'error'
            );

            // Log suspicious activity
            $this->log_suspicious_activity([
                'ip' => WC_Geolocation::get_ip_address(),
                'email' => $email,
                'score' => $fraud_score,
                'reasons' => $fraud_reasons,
            ]);
        }
    }

    /**
     * Check IP reputation
     */
    private function check_ip_reputation($ip) {
        // Check against known VPN/Proxy lists
        $vpn_check = $this->is_vpn_proxy($ip);
        if ($vpn_check) {
            return 40;
        }

        // Check against blacklists
        $blacklisted = $this->check_ip_blacklists($ip);
        if ($blacklisted) {
            return 60;
        }

        // Check geographic anomalies
        $geo_score = $this->check_geographic_anomalies($ip);

        return $geo_score;
    }

    /**
     * Implement 3D Secure
     */
    public function implement_3d_secure($order, $payment_method) {
        $amount = $order->get_total();

        // Always require 3D Secure for high-value transactions
        if ($amount > 500) {
            return [
                'required' => true,
                'reason' => 'high_value',
            ];
        }

        // Check fraud score
        $fraud_score = WC()->session->get('fraud_score', 0);
        if ($fraud_score > 50) {
            return [
                'required' => true,
                'reason' => 'fraud_risk',
            ];
        }

        // Check customer history
        $customer = $order->get_customer_id();
        if ($customer && $this->is_trusted_customer($customer)) {
            return [
                'required' => false,
                'reason' => 'trusted_customer',
            ];
        }

        // Default to requiring 3D Secure
        return [
            'required' => true,
            'reason' => 'default_policy',
        ];
    }
}

// Initialize security manager
new WC_Payment_Security_Manager();

Order Management and Fulfillment

Advanced Order Management System

// Comprehensive order management system
class WC_Advanced_Order_Manager {

    /**
     * Initialize order management features
     */
    public function __construct() {
        // Custom order statuses
        add_action('init', [$this, 'register_custom_order_statuses']);
        add_filter('wc_order_statuses', [$this, 'add_custom_order_statuses']);

        // Order actions
        add_filter('woocommerce_order_actions', [$this, 'add_custom_order_actions'], 10, 2);
        add_action('woocommerce_order_action_send_to_fulfillment', [$this, 'handle_send_to_fulfillment']);

        // Bulk actions
        add_filter('bulk_actions-edit-shop_order', [$this, 'add_bulk_actions']);
        add_filter('handle_bulk_actions-edit-shop_order', [$this, 'handle_bulk_actions'], 10, 3);

        // Order tracking
        add_action('woocommerce_order_status_changed', [$this, 'track_order_status_change'], 10, 4);

        // Automated workflows
        add_action('woocommerce_order_status_processing', [$this, 'automate_order_processing']);
    }

    /**
     * Register custom order statuses
     */
    public function register_custom_order_statuses() {
        register_post_status('wc-awaiting-shipment', [
            'label' => __('Awaiting Shipment', 'woocommerce'),
            'public' => true,
            'show_in_admin_status_list' => true,
            'show_in_admin_all_list' => true,
            'exclude_from_search' => false,
            'label_count' => _n_noop(
                'Awaiting Shipment <span class="count">(%s)</span>',
                'Awaiting Shipment <span class="count">(%s)</span>',
                'woocommerce'
            ),
        ]);

        register_post_status('wc-in-fulfillment', [
            'label' => __('In Fulfillment', 'woocommerce'),
            'public' => true,
            'show_in_admin_status_list' => true,
            'show_in_admin_all_list' => true,
            'exclude_from_search' => false,
            'label_count' => _n_noop(
                'In Fulfillment <span class="count">(%s)</span>',
                'In Fulfillment <span class="count">(%s)</span>',
                'woocommerce'
            ),
        ]);

        register_post_status('wc-quality-check', [
            'label' => __('Quality Check', 'woocommerce'),
            'public' => true,
            'show_in_admin_status_list' => true,
            'show_in_admin_all_list' => true,
            'exclude_from_search' => false,
            'label_count' => _n_noop(
                'Quality Check <span class="count">(%s)</span>',
                'Quality Check <span class="count">(%s)</span>',
                'woocommerce'
            ),
        ]);
    }

    /**
     * Automated order processing workflow
     */
    public function automate_order_processing($order_id) {
        $order = wc_get_order($order_id);

        if (!$order) {
            return;
        }

        // Check inventory availability
        $inventory_check = $this->check_inventory_availability($order);

        if (!$inventory_check['available']) {
            // Handle backorder
            $this->handle_backorder($order, $inventory_check['unavailable_items']);
            return;
        }

        // Allocate inventory
        $this->allocate_inventory($order);

        // Generate picking list
        $picking_list = $this->generate_picking_list($order);

        // Send to warehouse management system
        $this->send_to_wms($order, $picking_list);

        // Update order status
        $order->update_status('awaiting-shipment', __('Order sent to fulfillment center', 'woocommerce'));

        // Schedule status check
        wp_schedule_single_event(
            time() + HOUR_IN_SECONDS,
            'check_fulfillment_status',
            [$order_id]
        );
    }

    /**
     * Check inventory availability
     */
    private function check_inventory_availability($order) {
        $available = true;
        $unavailable_items = [];

        foreach ($order->get_items() as $item_id => $item) {
            $product = $item->get_product();

            if (!$product || !$product->managing_stock()) {
                continue;
            }

            $required_qty = $item->get_quantity();
            $available_qty = $product->get_stock_quantity();

            // Check warehouse availability
            $warehouse_stock = $this->get_warehouse_stock($product->get_id());

            if ($available_qty + $warehouse_stock < $required_qty) {
                $available = false;
                $unavailable_items[] = [
                    'product_id' => $product->get_id(),
                    'product_name' => $product->get_name(),
                    'required' => $required_qty,
                    'available' => $available_qty,
                    'warehouse' => $warehouse_stock,
                ];
            }
        }

        return [
            'available' => $available,
            'unavailable_items' => $unavailable_items,
        ];
    }

    /**
     * Generate picking list
     */
    private function generate_picking_list($order) {
        $picking_list = [
            'order_id' => $order->get_id(),
            'order_number' => $order->get_order_number(),
            'created_date' => current_time('mysql'),
            'priority' => $this->calculate_order_priority($order),
            'items' => [],
        ];

        foreach ($order->get_items() as $item_id => $item) {
            $product = $item->get_product();

            $picking_list['items'][] = [
                'line_item_id' => $item_id,
                'product_id' => $product->get_id(),
                'sku' => $product->get_sku(),
                'name' => $product->get_name(),
                'quantity' => $item->get_quantity(),
                'location' => get_post_meta($product->get_id(), '_warehouse_location', true),
                'weight' => $product->get_weight(),
                'dimensions' => [
                    'length' => $product->get_length(),
                    'width' => $product->get_width(),
                    'height' => $product->get_height(),
                ],
                'special_instructions' => $this->get_special_instructions($product),
            ];
        }

        // Calculate optimal picking route
        $picking_list['route'] = $this->calculate_picking_route($picking_list['items']);

        return $picking_list;
    }

    /**
     * Calculate optimal picking route
     */
    private function calculate_picking_route($items) {
        // Sort items by warehouse location for efficient picking
        usort($items, function($a, $b) {
            return strcmp($a['location'], $b['location']);
        });

        $route = [];
        $current_zone = '';

        foreach ($items as $item) {
            $zone = substr($item['location'], 0, 1); // First character is zone

            if ($zone !== $current_zone) {
                $route[] = [
                    'zone' => $zone,
                    'items' => [],
                ];
                $current_zone = $zone;
            }

            $route[count($route) - 1]['items'][] = [
                'location' => $item['location'],
                'sku' => $item['sku'],
                'quantity' => $item['quantity'],
            ];
        }

        return $route;
    }
}

// Initialize order manager
new WC_Advanced_Order_Manager();

Shipping and Fulfillment Integration

// Advanced shipping and fulfillment system
class WC_Fulfillment_Integration {

    /**
     * Initialize fulfillment integration
     */
    public function __construct() {
        // Shipping calculations
        add_filter('woocommerce_package_rates', [$this, 'calculate_shipping_rates'], 10, 2);

        // Label generation
        add_action('woocommerce_order_action_generate_shipping_label', [$this, 'generate_shipping_label']);

        // Tracking integration
        add_action('woocommerce_order_shipped', [$this, 'add_tracking_info']);

        // Multi-warehouse shipping
        add_filter('woocommerce_cart_shipping_packages', [$this, 'split_shipping_packages']);

        // Real-time rates
        add_action('wp_ajax_get_real_time_rates', [$this, 'ajax_get_real_time_rates']);
        add_action('wp_ajax_nopriv_get_real_time_rates', [$this, 'ajax_get_real_time_rates']);
    }

    /**
     * Calculate shipping rates with multiple carriers
     */
    public function calculate_shipping_rates($rates, $package) {
        // Get package details
        $weight = $this->calculate_package_weight($package);
        $dimensions = $this->calculate_package_dimensions($package);
        $destination = $package['destination'];

        // Check cache first
        $cache_key = $this->generate_rate_cache_key($package);
        $cached_rates = get_transient($cache_key);

        if ($cached_rates !== false) {
            return $cached_rates;
        }

        // Get rates from multiple carriers
        $carrier_rates = [];

        // FedEx
        $fedex_rates = $this->get_fedex_rates($weight, $dimensions, $destination);
        foreach ($fedex_rates as $rate) {
            $carrier_rates[] = $this->format_shipping_rate('fedex', $rate);
        }

        // UPS
        $ups_rates = $this->get_ups_rates($weight, $dimensions, $destination);
        foreach ($ups_rates as $rate) {
            $carrier_rates[] = $this->format_shipping_rate('ups', $rate);
        }

        // USPS
        $usps_rates = $this->get_usps_rates($weight, $dimensions, $destination);
        foreach ($usps_rates as $rate) {
            $carrier_rates[] = $this->format_shipping_rate('usps', $rate);
        }

        // Add carrier rates to WooCommerce rates
        foreach ($carrier_rates as $rate) {
            $rates[$rate['id']] = $rate;
        }

        // Cache rates for 1 hour
        set_transient($cache_key, $rates, HOUR_IN_SECONDS);

        return $rates;
    }

    /**
     * Get FedEx rates
     */
    private function get_fedex_rates($weight, $dimensions, $destination) {
        $fedex_api = new FedEx_API(
            get_option('wc_fedex_account_number'),
            get_option('wc_fedex_meter_number'),
            get_option('wc_fedex_key'),
            get_option('wc_fedex_password')
        );

        $origin = [
            'postal_code' => get_option('woocommerce_store_postcode'),
            'country_code' => get_option('woocommerce_default_country'),
        ];

        $rates = $fedex_api->get_rates([
            'origin' => $origin,
            'destination' => $destination,
            'weight' => $weight,
            'dimensions' => $dimensions,
            'services' => ['FEDEX_GROUND', 'FEDEX_EXPRESS_SAVER', 'PRIORITY_OVERNIGHT'],
        ]);

        return $rates;
    }

    /**
     * Generate shipping label
     */
    public function generate_shipping_label($order) {
        try {
            // Get selected shipping method
            $shipping_methods = $order->get_shipping_methods();
            $shipping_method = reset($shipping_methods);

            if (!$shipping_method) {
                throw new Exception(__('No shipping method found', 'woocommerce'));
            }

            // Parse carrier and service from method ID
            list($carrier, $service) = explode(':', $shipping_method->get_method_id());

            // Generate label based on carrier
            switch ($carrier) {
                case 'fedex':
                    $label_data = $this->generate_fedex_label($order, $service);
                    break;

                case 'ups':
                    $label_data = $this->generate_ups_label($order, $service);
                    break;

                case 'usps':
                    $label_data = $this->generate_usps_label($order, $service);
                    break;

                default:
                    throw new Exception(__('Unsupported carrier', 'woocommerce'));
            }

            // Save label data
            $order->update_meta_data('_shipping_label_url', $label_data['label_url']);
            $order->update_meta_data('_tracking_number', $label_data['tracking_number']);
            $order->update_meta_data('_shipping_label_cost', $label_data['cost']);
            $order->save();

            // Add order note
            $order->add_order_note(sprintf(
                __('Shipping label generated. Tracking: %s', 'woocommerce'),
                $label_data['tracking_number']
            ));

            // Send tracking email
            do_action('woocommerce_order_shipped', $order->get_id(), $label_data['tracking_number']);

        } catch (Exception $e) {
            $order->add_order_note(sprintf(
                __('Failed to generate shipping label: %s', 'woocommerce'),
                $e->getMessage()
            ));
        }
    }

    /**
     * Multi-warehouse package splitting
     */
    public function split_shipping_packages($packages) {
        if (!WC()->cart || WC()->cart->is_empty()) {
            return $packages;
        }

        // Group items by warehouse
        $warehouse_items = [];

        foreach (WC()->cart->get_cart() as $cart_item_key => $cart_item) {
            $product_id = $cart_item['product_id'];
            $warehouse = $this->get_product_warehouse($product_id);

            if (!isset($warehouse_items[$warehouse])) {
                $warehouse_items[$warehouse] = [];
            }

            $warehouse_items[$warehouse][$cart_item_key] = $cart_item;
        }

        // Create separate packages for each warehouse
        $packages = [];
        $package_index = 1;

        foreach ($warehouse_items as $warehouse => $items) {
            $packages[] = [
                'contents' => $items,
                'contents_cost' => array_sum(wp_list_pluck($items, 'line_total')),
                'applied_coupons' => WC()->cart->get_applied_coupons(),
                'user' => [
                    'ID' => get_current_user_id(),
                ],
                'destination' => WC()->customer->get_shipping(),
                'warehouse' => $warehouse,
                'package_name' => sprintf(__('Package %d (Ships from %s)', 'woocommerce'), $package_index, $warehouse),
            ];

            $package_index++;
        }

        return $packages;
    }
}

// Initialize fulfillment integration
new WC_Fulfillment_Integration();

Performance Optimization

WooCommerce Performance Optimization

// Comprehensive WooCommerce performance optimization
class WC_Performance_Optimizer {

    /**
     * Initialize performance optimizations
     */
    public function __construct() {
        // Database optimizations
        add_action('init', [$this, 'optimize_database_queries']);

        // Caching strategies
        add_action('init', [$this, 'implement_caching']);

        // Asset optimization
        add_action('wp_enqueue_scripts', [$this, 'optimize_assets'], 999);

        // AJAX optimization
        add_filter('woocommerce_ajax_variation_threshold', [$this, 'optimize_ajax_threshold']);

        // Background processing
        add_action('init', [$this, 'setup_background_processing']);

        // Query optimizations
        add_filter('woocommerce_product_query_tax_query', [$this, 'optimize_product_queries'], 10, 2);
        add_filter('woocommerce_order_data_store_cpt_get_orders_query', [$this, 'optimize_order_queries'], 10, 2);
    }

    /**
     * Optimize database queries
     */
    public function optimize_database_queries() {
        // Enable HPOS (High-Performance Order Storage)
        if (!get_option('woocommerce_hpos_enabled')) {
            update_option('woocommerce_feature_custom_order_tables_enabled', 'yes');
        }

        // Optimize cart session handling
        add_filter('woocommerce_session_handler_class', function() {
            return 'WC_Session_Handler_Optimized';
        });

        // Limit transient storage
        add_filter('woocommerce_transient_expiration', function($expiration, $transient) {
            // Reduce transient expiration for non-critical data
            if (strpos($transient, 'wc_product_loop') !== false) {
                return HOUR_IN_SECONDS;
            }
            return $expiration;
        }, 10, 2);

        // Index optimization
        $this->create_performance_indexes();
    }

    /**
     * Create performance indexes
     */
    private function create_performance_indexes() {
        global $wpdb;

        $indexes = [
            // Product performance indexes
            [
                'table' => $wpdb->postmeta,
                'name' => 'wc_product_meta_lookup',
                'columns' => "post_id, meta_key(20), meta_value(20)",
                'condition' => "WHERE meta_key IN ('_price', '_sale_price', '_sku', '_stock')",
            ],
            // Order performance indexes
            [
                'table' => $wpdb->prefix . 'wc_order_stats',
                'name' => 'wc_order_stats_date_status',
                'columns' => 'date_created, status(20)',
            ],
            // Customer lookup
            [
                'table' => $wpdb->prefix . 'wc_customer_lookup',
                'name' => 'wc_customer_email',
                'columns' => 'email(50)',
            ],
        ];

        foreach ($indexes as $index) {
            $this->create_index_if_not_exists(
                $index['table'],
                $index['name'],
                $index['columns'],
                $index['condition'] ?? ''
            );
        }
    }

    /**
     * Implement caching strategies
     */
    public function implement_caching() {
        // Product cache warming
        add_action('save_post_product', [$this, 'warm_product_cache'], 10, 3);

        // Implement fragment caching
        add_filter('woocommerce_add_to_cart_fragments', [$this, 'optimize_cart_fragments']);

        // Cache expensive calculations
        add_filter('woocommerce_calculated_total', [$this, 'cache_cart_calculations'], 10, 2);

        // Implement Redis object caching if available
        if (class_exists('Redis')) {
            $this->setup_redis_caching();
        }
    }

    /**
     * Setup Redis caching
     */
    private function setup_redis_caching() {
        // Initialize Redis connection
        $redis = new Redis();
        $redis->connect('127.0.0.1', 6379);

        // Cache product data
        add_filter('woocommerce_product_get_price', function($price, $product) use ($redis) {
            $cache_key = 'wc_product_price_' . $product->get_id();

            $cached_price = $redis->get($cache_key);
            if ($cached_price !== false) {
                return $cached_price;
            }

            $redis->setex($cache_key, 3600, $price);
            return $price;
        }, 10, 2);

        // Cache expensive queries
        add_filter('posts_pre_query', function($posts, $query) use ($redis) {
            if (!$query->is_main_query() || !$query->get('post_type') === 'product') {
                return $posts;
            }

            $cache_key = 'wc_query_' . md5(serialize($query->query_vars));
            $cached_results = $redis->get($cache_key);

            if ($cached_results !== false) {
                return unserialize($cached_results);
            }

            return $posts;
        }, 10, 2);
    }

    /**
     * Optimize assets loading
     */
    public function optimize_assets() {
        // Remove unnecessary scripts on non-WooCommerce pages
        if (!is_woocommerce() && !is_cart() && !is_checkout() && !is_account_page()) {
            wp_dequeue_script('wc-cart-fragments');
            wp_dequeue_script('woocommerce');
            wp_dequeue_script('wc-add-to-cart');
            wp_dequeue_style('woocommerce-general');
            wp_dequeue_style('woocommerce-layout');
            wp_dequeue_style('woocommerce-smallscreen');
        }

        // Defer non-critical JavaScript
        add_filter('script_loader_tag', function($tag, $handle) {
            $defer_scripts = [
                'wc-add-to-cart-variation',
                'wc-single-product',
                'wc-geolocation',
            ];

            if (in_array($handle, $defer_scripts)) {
                return str_replace(' src', ' defer src', $tag);
            }

            return $tag;
        }, 10, 2);

        // Preload critical assets
        $this->preload_critical_assets();
    }

    /**
     * Background processing setup
     */
    public function setup_background_processing() {
        // Process heavy operations in background
        add_action('woocommerce_new_order', function($order_id) {
            wp_schedule_single_event(time() + 10, 'process_order_analytics', [$order_id]);
        });

        // Background product sync
        add_action('woocommerce_update_product', function($product_id) {
            wp_schedule_single_event(time() + 30, 'sync_product_data', [$product_id]);
        });

        // Batch processing for reports
        add_action('woocommerce_after_register_post_type', function() {
            if (!wp_next_scheduled('generate_analytics_cache')) {
                wp_schedule_event(time(), 'hourly', 'generate_analytics_cache');
            }
        });
    }
}

// Initialize performance optimizer
new WC_Performance_Optimizer();

// Optimized session handler
class WC_Session_Handler_Optimized extends WC_Session_Handler {

    /**
     * Optimize session cleanup
     */
    public function cleanup_sessions() {
        global $wpdb;

        // Use direct query for better performance
        $wpdb->query($wpdb->prepare(
            "DELETE FROM {$wpdb->prefix}woocommerce_sessions 
             WHERE session_expiry < %d 
             LIMIT 1000",
            time()
        ));

        // Schedule next cleanup
        wp_schedule_single_event(time() + HOUR_IN_SECONDS, 'woocommerce_cleanup_sessions');
    }
}

Security and Compliance

E-commerce Security Implementation

// Comprehensive e-commerce security system
class WC_Security_Manager {

    /**
     * Initialize security features
     */
    public function __construct() {
        // PCI compliance
        add_action('init', [$this, 'enforce_pci_compliance']);

        // Data protection
        add_filter('woocommerce_checkout_fields', [$this, 'add_gdpr_consent_fields']);
        add_action('woocommerce_checkout_create_order', [$this, 'save_gdpr_consent'], 10, 2);

        // Security headers
        add_action('send_headers', [$this, 'add_security_headers']);

        // Input validation
        add_action('woocommerce_checkout_process', [$this, 'validate_checkout_security']);

        // API security
        add_filter('woocommerce_api_check_authentication', [$this, 'enhance_api_security'], 10, 2);

        // File upload security
        add_filter('upload_mimes', [$this, 'restrict_upload_mimes']);
        add_filter('wp_handle_upload_prefilter', [$this, 'scan_uploaded_files']);
    }

    /**
     * Enforce PCI compliance
     */
    public function enforce_pci_compliance() {
        // Force SSL on checkout
        if (is_checkout() && !is_ssl()) {
            wp_redirect('https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'], 301);
            exit;
        }

        // Disable card storage
        add_filter('woocommerce_payment_gateways_save_payment_method_checkbox', '__return_false');

        // Implement Content Security Policy
        add_action('wp_head', function() {
            if (is_checkout()) {
                ?>
                <meta http-equiv="Content-Security-Policy" content="
                    default-src 'self';
                    script-src 'self' 'unsafe-inline' https://js.stripe.com https://checkout.paypal.com;
                    style-src 'self' 'unsafe-inline';
                    img-src 'self' data: https:;
                    connect-src 'self' https://api.stripe.com;
                    frame-src 'self' https://js.stripe.com https://checkout.paypal.com;
                ">
                <?php
            }
        });
    }

    /**
     * Add security headers
     */
    public function add_security_headers() {
        header('X-Content-Type-Options: nosniff');
        header('X-Frame-Options: SAMEORIGIN');
        header('X-XSS-Protection: 1; mode=block');
        header('Referrer-Policy: strict-origin-when-cross-origin');
        header('Permissions-Policy: geolocation=(), microphone=(), camera=()');

        if (is_ssl()) {
            header('Strict-Transport-Security: max-age=31536000; includeSubDomains');
        }
    }

    /**
     * GDPR compliance
     */
    public function add_gdpr_consent_fields($fields) {
        $fields['order']['gdpr_consent'] = [
            'type' => 'checkbox',
            'label' => __('I consent to the storage and processing of my data in accordance with the privacy policy', 'woocommerce'),
            'required' => true,
            'class' => ['gdpr-consent-field'],
            'priority' => 999,
        ];

        return $fields;
    }

    /**
     * Validate checkout security
     */
    public function validate_checkout_security() {
        // Rate limiting
        $this->check_checkout_rate_limit();

        // Validate nonce
        if (!wp_verify_nonce($_POST['woocommerce-process-checkout-nonce'], 'woocommerce-process_checkout')) {
            wc_add_notice(__('Security check failed. Please refresh and try again.', 'woocommerce'), 'error');
        }

        // Check for suspicious patterns
        $this->detect_malicious_input($_POST);

        // Validate email format strictly
        if (!filter_var($_POST['billing_email'], FILTER_VALIDATE_EMAIL)) {
            wc_add_notice(__('Please enter a valid email address.', 'woocommerce'), 'error');
        }
    }

    /**
     * Detect malicious input
     */
    private function detect_malicious_input($data) {
        $suspicious_patterns = [
            '/<script[^>]*>.*?<\/script>/is',
            '/on\w+\s*=\s*["\'].*?["\']/i',
            '/javascript\s*:/i',
            '/base64_decode/i',
            '/eval\s*\(/i',
            '/exec\s*\(/i',
        ];

        foreach ($data as $key => $value) {
            if (is_string($value)) {
                foreach ($suspicious_patterns as $pattern) {
                    if (preg_match($pattern, $value)) {
                        wc_add_notice(__('Invalid input detected. Please check your data.', 'woocommerce'), 'error');

                        // Log security event
                        $this->log_security_event('malicious_input', [
                            'field' => $key,
                            'pattern' => $pattern,
                            'ip' => $_SERVER['REMOTE_ADDR'],
                        ]);

                        return;
                    }
                }
            }
        }
    }

    /**
     * Enhanced API security
     */
    public function enhance_api_security($user, $consumer) {
        // Implement OAuth 2.0
        if (get_option('woocommerce_api_oauth2_enabled')) {
            return $this->validate_oauth2_token();
        }

        // Rate limiting for API
        $this->check_api_rate_limit($consumer);

        // IP whitelist check
        if (!$this->is_ip_whitelisted($_SERVER['REMOTE_ADDR'])) {
            return new WP_Error('forbidden', __('Access denied from this IP', 'woocommerce'), ['status' => 403]);
        }

        return $user;
    }
}

// Initialize security manager
new WC_Security_Manager();

Advanced Features and Integrations

Multi-vendor Marketplace

// Multi-vendor marketplace implementation
class WC_Multivendor_Marketplace {

    /**
     * Initialize marketplace features
     */
    public function __construct() {
        // Vendor registration
        add_action('init', [$this, 'register_vendor_role']);
        add_shortcode('vendor_registration', [$this, 'vendor_registration_form']);

        // Vendor dashboard
        add_action('init', [$this, 'add_vendor_endpoints']);
        add_filter('woocommerce_account_menu_items', [$this, 'add_vendor_menu_items']);

        // Product management
        add_filter('woocommerce_product_data_store_cpt_get_products_query', [$this, 'filter_vendor_products'], 10, 2);

        // Commission management
        add_action('woocommerce_order_status_completed', [$this, 'calculate_vendor_commission']);

        // Vendor shipping
        add_filter('woocommerce_package_rates', [$this, 'vendor_shipping_rates'], 10, 2);
    }

    /**
     * Register vendor role
     */
    public function register_vendor_role() {
        add_role('vendor', __('Vendor', 'woocommerce'), [
            'read' => true,
            'edit_posts' => false,
            'delete_posts' => false,
            'publish_posts' => false,
            'upload_files' => true,

            // Product capabilities
            'edit_products' => true,
            'publish_products' => false, // Require approval
            'read_private_products' => true,
            'delete_products' => true,
            'edit_private_products' => true,
            'delete_private_products' => true,
            'edit_published_products' => true,
            'delete_published_products' => true,

            // Shop order capabilities
            'read_shop_orders' => true,
            'edit_shop_orders' => true,
        ]);
    }

    /**
     * Vendor registration form
     */
    public function vendor_registration_form() {
        if (is_user_logged_in()) {
            return '<p>' . __('You are already registered.', 'woocommerce') . '</p>';
        }

        ob_start();
        ?>
        <form method="post" class="vendor-registration-form">
            <?php wp_nonce_field('vendor_registration', 'vendor_nonce'); ?>

            <p class="form-row">
                <label for="vendor_name"><?php esc_html_e('Store Name', 'woocommerce'); ?> <span class="required">*</span></label>
                <input type="text" class="input-text" name="vendor_name" id="vendor_name" required />
            </p>

            <p class="form-row">
                <label for="vendor_email"><?php esc_html_e('Email', 'woocommerce'); ?> <span class="required">*</span></label>
                <input type="email" class="input-text" name="vendor_email" id="vendor_email" required />
            </p>

            <p class="form-row">
                <label for="vendor_description"><?php esc_html_e('Store Description', 'woocommerce'); ?></label>
                <textarea name="vendor_description" id="vendor_description" rows="4"></textarea>
            </p>

            <p class="form-row">
                <label for="vendor_location"><?php esc_html_e('Location', 'woocommerce'); ?></label>
                <input type="text" class="input-text" name="vendor_location" id="vendor_location" />
            </p>

            <p class="form-row">
                <label for="vendor_paypal"><?php esc_html_e('PayPal Email (for payments)', 'woocommerce'); ?> <span class="required">*</span></label>
                <input type="email" class="input-text" name="vendor_paypal" id="vendor_paypal" required />
            </p>

            <p class="form-row">
                <button type="submit" class="button" name="register_vendor"><?php esc_html_e('Register as Vendor', 'woocommerce'); ?></button>
            </p>
        </form>
        <?php

        return ob_get_clean();
    }

    /**
     * Calculate vendor commission
     */
    public function calculate_vendor_commission($order_id) {
        $order = wc_get_order($order_id);

        if (!$order) {
            return;
        }

        $vendor_commissions = [];

        foreach ($order->get_items() as $item) {
            $product = $item->get_product();
            $vendor_id = get_post_field('post_author', $product->get_id());

            if (!user_can($vendor_id, 'vendor')) {
                continue;
            }

            // Get commission rate
            $commission_rate = $this->get_vendor_commission_rate($vendor_id, $product);

            // Calculate commission
            $line_total = $item->get_total();
            $commission = $line_total * ($commission_rate / 100);

            if (!isset($vendor_commissions[$vendor_id])) {
                $vendor_commissions[$vendor_id] = 0;
            }

            $vendor_commissions[$vendor_id] += $commission;
        }

        // Save commissions
        foreach ($vendor_commissions as $vendor_id => $commission) {
            $this->create_commission_record($order_id, $vendor_id, $commission);
        }
    }

    /**
     * Get vendor commission rate
     */
    private function get_vendor_commission_rate($vendor_id, $product) {
        // Check product-specific rate
        $product_rate = get_post_meta($product->get_id(), '_vendor_commission_rate', true);
        if ($product_rate) {
            return floatval($product_rate);
        }

        // Check vendor-specific rate
        $vendor_rate = get_user_meta($vendor_id, 'commission_rate', true);
        if ($vendor_rate) {
            return floatval($vendor_rate);
        }

        // Check category-specific rate
        $categories = wp_get_post_terms($product->get_id(), 'product_cat', ['fields' => 'ids']);
        foreach ($categories as $cat_id) {
            $cat_rate = get_term_meta($cat_id, 'vendor_commission_rate', true);
            if ($cat_rate) {
                return floatval($cat_rate);
            }
        }

        // Default rate
        return floatval(get_option('default_vendor_commission_rate', 80));
    }
}

// Initialize marketplace
new WC_Multivendor_Marketplace();

Advanced Analytics and Reporting

// Advanced analytics system
class WC_Advanced_Analytics {

    /**
     * Initialize analytics
     */
    public function __construct() {
        // Custom reports
        add_filter('woocommerce_admin_reports', [$this, 'add_custom_reports']);

        // Real-time analytics
        add_action('woocommerce_new_order', [$this, 'track_real_time_sale']);
        add_action('woocommerce_add_to_cart', [$this, 'track_add_to_cart']);

        // Customer analytics
        add_action('woocommerce_created_customer', [$this, 'track_customer_acquisition']);

        // Product analytics
        add_action('woocommerce_before_single_product', [$this, 'track_product_view']);

        // Export functionality
        add_action('admin_init', [$this, 'handle_analytics_export']);
    }

    /**
     * Add custom reports
     */
    public function add_custom_reports($reports) {
        $reports['advanced'] = [
            'title' => __('Advanced Analytics', 'woocommerce'),
            'reports' => [
                'cohort_analysis' => [
                    'title' => __('Cohort Analysis', 'woocommerce'),
                    'description' => __('Analyze customer behavior over time', 'woocommerce'),
                    'callback' => [$this, 'cohort_analysis_report'],
                ],
                'product_performance' => [
                    'title' => __('Product Performance', 'woocommerce'),
                    'description' => __('Detailed product analytics', 'woocommerce'),
                    'callback' => [$this, 'product_performance_report'],
                ],
                'customer_lifetime_value' => [
                    'title' => __('Customer Lifetime Value', 'woocommerce'),
                    'description' => __('CLV analysis and predictions', 'woocommerce'),
                    'callback' => [$this, 'clv_report'],
                ],
                'conversion_funnel' => [
                    'title' => __('Conversion Funnel', 'woocommerce'),
                    'description' => __('Shopping cart abandonment analysis', 'woocommerce'),
                    'callback' => [$this, 'conversion_funnel_report'],
                ],
            ],
        ];

        return $reports;
    }

    /**
     * Cohort analysis report
     */
    public function cohort_analysis_report() {
        global $wpdb;

        // Get cohorts by month
        $cohorts = $wpdb->get_results("
            SELECT 
                DATE_FORMAT(date_registered, '%Y-%m') as cohort_month,
                COUNT(DISTINCT user_id) as customers
            FROM {$wpdb->prefix}wc_customer_lookup
            WHERE date_registered >= DATE_SUB(NOW(), INTERVAL 12 MONTH)
            GROUP BY cohort_month
            ORDER BY cohort_month
        ");

        $cohort_data = [];

        foreach ($cohorts as $cohort) {
            $cohort_month = $cohort->cohort_month;

            // Get retention data for each month
            for ($month = 0; $month <= 12; $month++) {
                $retention = $wpdb->get_var($wpdb->prepare("
                    SELECT COUNT(DISTINCT o.customer_id) / %d * 100
                    FROM {$wpdb->prefix}wc_order_stats o
                    JOIN {$wpdb->prefix}wc_customer_lookup c ON o.customer_id = c.customer_id
                    WHERE DATE_FORMAT(c.date_registered, '%%Y-%%m') = %s
                    AND DATE_FORMAT(o.date_created, '%%Y-%%m') = DATE_FORMAT(DATE_ADD(c.date_registered, INTERVAL %d MONTH), '%%Y-%%m')
                    AND o.status IN ('wc-completed', 'wc-processing')
                ", $cohort->customers, $cohort_month, $month));

                $cohort_data[$cohort_month][$month] = round($retention, 1);
            }
        }

        $this->render_cohort_table($cohort_data);
    }

    /**
     * Customer lifetime value calculation
     */
    public function calculate_customer_lifetime_value($customer_id) {
        global $wpdb;

        // Get customer order history
        $order_data = $wpdb->get_row($wpdb->prepare("
            SELECT 
                COUNT(*) as order_count,
                SUM(total_sales) as total_spent,
                MIN(date_created) as first_order,
                MAX(date_created) as last_order,
                AVG(total_sales) as avg_order_value
            FROM {$wpdb->prefix}wc_order_stats
            WHERE customer_id = %d
            AND status IN ('wc-completed', 'wc-processing')
        ", $customer_id));

        if (!$order_data || $order_data->order_count == 0) {
            return 0;
        }

        // Calculate customer age in days
        $customer_age_days = (strtotime($order_data->last_order) - strtotime($order_data->first_order)) / 86400;
        $customer_age_days = max($customer_age_days, 1);

        // Calculate purchase frequency (orders per year)
        $purchase_frequency = ($order_data->order_count / $customer_age_days) * 365;

        // Estimate customer lifespan (years)
        $churn_rate = $this->calculate_churn_rate();
        $customer_lifespan = 1 / $churn_rate;

        // CLV = Average Order Value × Purchase Frequency × Customer Lifespan
        $clv = $order_data->avg_order_value * $purchase_frequency * $customer_lifespan;

        return round($clv, 2);
    }
}

// Initialize analytics
new WC_Advanced_Analytics();

Next Steps and Resources

With this comprehensive foundation in WooCommerce development, you're equipped to build sophisticated e-commerce solutions. To continue advancing your skills:

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  9. WooCommerce Security Best Practices - Comprehensive security implementation for e-commerce

Key Takeaways

Continue Learning

  1. Join the Community: Participate in WooCommerce developer forums and contribute to open source
  2. Stay Updated: Follow WooCommerce development blog for latest features and best practices
  3. Build Projects: Create real-world e-commerce solutions to apply your knowledge
  4. Get Certified: Consider WooCommerce developer certification for credibility

Remember, successful e-commerce development combines technical expertise with understanding business needs. Focus on creating solutions that drive conversions while maintaining performance and security.


Last updated: July 12, 2025