Implement version 0.0.2 features

Add product version management:
- ProductVersion model and VersionManager class
- VersionAdminController with meta box on product edit page
- AJAX-based version CRUD (add, delete, toggle status)
- JavaScript for version management UI

Add email notifications:
- LicenseEmailController for order emails
- License keys included in order completed emails
- Support for both HTML and plain text emails

Add REST API rate limiting:
- 30 requests per minute per IP
- Cloudflare and proxy-aware IP detection
- HTTP 429 response with Retry-After header

Other changes:
- Bump version to 0.0.2
- Update CHANGELOG.md
- Add version status styles to admin.css

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -7,7 +7,31 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-## [0.0.1] - 2024-01-21
+## [0.0.2] - 2026-01-21
+
+### Added
+
+- Product version management UI in admin (meta box on product edit page)
+- AJAX-based version CRUD operations (add, delete, toggle active status)
+- ProductVersion model and VersionManager for version data handling
+- Email notifications with license keys on order completion
+- License information included in WooCommerce order completed emails
+- Rate limiting for REST API endpoints (30 requests/minute per IP)
+- Cloudflare and proxy-aware IP detection for rate limiting
+- JavaScript for version management interactions
+
+### Changed
+
+- Declared WooCommerce HPOS and cart/checkout blocks compatibility
+- Plugin name changed from "WC Licensed Product" to "WooCommerce Licensed Product"
+
+### Technical Details
+
+- New classes: ProductVersion, VersionManager, VersionAdminController, LicenseEmailController
+- Rate limiting uses WordPress transients for request counting
+- HTTP 429 response with Retry-After header when rate limited
+
+## [0.0.1] - 2026-01-21
 
 ### Added
 
@@ -44,5 +68,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - WordPress REST API integration
 - Custom WooCommerce product type extending WC_Product
 
-[Unreleased]: https://src.bundespruefstelle.ch/magdev/wc-licensed-product/compare/v0.0.1...HEAD
+[Unreleased]: https://src.bundespruefstelle.ch/magdev/wc-licensed-product/compare/v0.0.2...HEAD
+[0.0.2]: https://src.bundespruefstelle.ch/magdev/wc-licensed-product/compare/v0.0.1...v0.0.2
 [0.0.1]: https://src.bundespruefstelle.ch/magdev/wc-licensed-product/releases/tag/v0.0.1

assets/css/admin.css

@@ -89,3 +89,59 @@
 .column-license .dashicons-admin-network {
     color: #2271b1;
 }
+
+/* Version Status Badges */
+.version-status {
+    display: inline-block;
+    padding: 0.2em 0.5em;
+    font-size: 0.85em;
+    font-weight: 500;
+    line-height: 1.2;
+    border-radius: 3px;
+}
+
+.version-status-active {
+    background-color: #d4edda;
+    color: #155724;
+}
+
+.version-status-inactive {
+    background-color: #fff3cd;
+    color: #856404;
+}
+
+/* Version Meta Box */
+.wc-licensed-product-versions .versions-add-form {
+    background: #f9f9f9;
+    padding: 15px;
+    border: 1px solid #e5e5e5;
+    border-radius: 4px;
+    margin-bottom: 20px;
+}
+
+.wc-licensed-product-versions .versions-add-form h4 {
+    margin-top: 0;
+}
+
+.wc-licensed-product-versions .form-table {
+    margin: 0;
+}
+
+.wc-licensed-product-versions .form-table th {
+    padding: 10px 10px 10px 0;
+    width: 120px;
+}
+
+.wc-licensed-product-versions .form-table td {
+    padding: 10px 0;
+}
+
+#versions-table {
+    margin-top: 10px;
+}
+
+#versions-table .no-versions td {
+    text-align: center;
+    font-style: italic;
+    color: #666;
+}

assets/js/versions.js

@@ -0,0 +1,181 @@
+/**
+ * WC Licensed Product - Version Management
+ *
+ * @package Jeremias\WcLicensedProduct
+ */
+
+(function($) {
+    'use strict';
+
+    var WCLicensedProductVersions = {
+        init: function() {
+            this.bindEvents();
+        },
+
+        bindEvents: function() {
+            $('#add-version-btn').on('click', this.addVersion);
+            $(document).on('click', '.delete-version-btn', this.deleteVersion);
+            $(document).on('click', '.toggle-version-btn', this.toggleVersion);
+        },
+
+        addVersion: function(e) {
+            e.preventDefault();
+
+            var $btn = $(this);
+            var $spinner = $btn.siblings('.spinner');
+            var productId = $btn.data('product-id');
+            var version = $('#new_version').val().trim();
+            var downloadUrl = $('#new_download_url').val().trim();
+            var releaseNotes = $('#new_release_notes').val().trim();
+
+            // Validate version
+            if (!version) {
+                alert(wcLicensedProductVersions.strings.versionRequired);
+                return;
+            }
+
+            if (!/^\d+\.\d+\.\d+$/.test(version)) {
+                alert(wcLicensedProductVersions.strings.versionInvalid);
+                return;
+            }
+
+            $btn.prop('disabled', true);
+            $spinner.addClass('is-active');
+
+            $.ajax({
+                url: wcLicensedProductVersions.ajaxUrl,
+                type: 'POST',
+                data: {
+                    action: 'wc_licensed_product_add_version',
+                    nonce: wcLicensedProductVersions.nonce,
+                    product_id: productId,
+                    version: version,
+                    download_url: downloadUrl,
+                    release_notes: releaseNotes
+                },
+                success: function(response) {
+                    if (response.success) {
+                        // Remove "no versions" row if present
+                        $('#versions-table tbody .no-versions').remove();
+
+                        // Add new row to table
+                        $('#versions-table tbody').prepend(response.data.html);
+
+                        // Clear form
+                        $('#new_version').val('');
+                        $('#new_download_url').val('');
+                        $('#new_release_notes').val('');
+                    } else {
+                        alert(response.data.message || wcLicensedProductVersions.strings.error);
+                    }
+                },
+                error: function() {
+                    alert(wcLicensedProductVersions.strings.error);
+                },
+                complete: function() {
+                    $btn.prop('disabled', false);
+                    $spinner.removeClass('is-active');
+                }
+            });
+        },
+
+        deleteVersion: function(e) {
+            e.preventDefault();
+
+            if (!confirm(wcLicensedProductVersions.strings.confirmDelete)) {
+                return;
+            }
+
+            var $btn = $(this);
+            var $row = $btn.closest('tr');
+            var versionId = $btn.data('version-id');
+
+            $btn.prop('disabled', true);
+
+            $.ajax({
+                url: wcLicensedProductVersions.ajaxUrl,
+                type: 'POST',
+                data: {
+                    action: 'wc_licensed_product_delete_version',
+                    nonce: wcLicensedProductVersions.nonce,
+                    version_id: versionId
+                },
+                success: function(response) {
+                    if (response.success) {
+                        $row.fadeOut(300, function() {
+                            $(this).remove();
+
+                            // Show "no versions" message if table is empty
+                            if ($('#versions-table tbody tr').length === 0) {
+                                $('#versions-table tbody').append(
+                                    '<tr class="no-versions"><td colspan="6">' +
+                                    'No versions found. Add your first version above.' +
+                                    '</td></tr>'
+                                );
+                            }
+                        });
+                    } else {
+                        alert(response.data.message || wcLicensedProductVersions.strings.error);
+                        $btn.prop('disabled', false);
+                    }
+                },
+                error: function() {
+                    alert(wcLicensedProductVersions.strings.error);
+                    $btn.prop('disabled', false);
+                }
+            });
+        },
+
+        toggleVersion: function(e) {
+            e.preventDefault();
+
+            var $btn = $(this);
+            var $row = $btn.closest('tr');
+            var versionId = $btn.data('version-id');
+            var currentlyActive = $btn.data('active') === 1 || $btn.data('active') === '1';
+
+            $btn.prop('disabled', true);
+
+            $.ajax({
+                url: wcLicensedProductVersions.ajaxUrl,
+                type: 'POST',
+                data: {
+                    action: 'wc_licensed_product_toggle_version',
+                    nonce: wcLicensedProductVersions.nonce,
+                    version_id: versionId,
+                    currently_active: currentlyActive ? 1 : 0
+                },
+                success: function(response) {
+                    if (response.success) {
+                        var isActive = response.data.isActive;
+                        var $status = $row.find('.version-status');
+
+                        // Update status badge
+                        $status
+                            .removeClass('version-status-active version-status-inactive')
+                            .addClass('version-status-' + (isActive ? 'active' : 'inactive'))
+                            .text(isActive ? 'Active' : 'Inactive');
+
+                        // Update button
+                        $btn
+                            .data('active', isActive ? 1 : 0)
+                            .text(isActive ? 'Deactivate' : 'Activate');
+                    } else {
+                        alert(response.data.message || wcLicensedProductVersions.strings.error);
+                    }
+                },
+                error: function() {
+                    alert(wcLicensedProductVersions.strings.error);
+                },
+                complete: function() {
+                    $btn.prop('disabled', false);
+                }
+            });
+        }
+    };
+
+    $(document).ready(function() {
+        WCLicensedProductVersions.init();
+    });
+
+})(jQuery);

src/Admin/VersionAdminController.php

@@ -0,0 +1,347 @@
+<?php
+/**
+ * Version Admin Controller
+ *
+ * @package Jeremias\WcLicensedProduct\Admin
+ */
+
+declare(strict_types=1);
+
+namespace Jeremias\WcLicensedProduct\Admin;
+
+use Jeremias\WcLicensedProduct\Product\VersionManager;
+
+/**
+ * Handles admin UI for product version management
+ */
+final class VersionAdminController
+{
+    private VersionManager $versionManager;
+
+    public function __construct(VersionManager $versionManager)
+    {
+        $this->versionManager = $versionManager;
+        $this->registerHooks();
+    }
+
+    /**
+     * Register WordPress hooks
+     */
+    private function registerHooks(): void
+    {
+        // Add versions meta box to licensed products
+        add_action('add_meta_boxes', [$this, 'addVersionsMetaBox']);
+
+        // Handle AJAX actions for version management
+        add_action('wp_ajax_wc_licensed_product_add_version', [$this, 'ajaxAddVersion']);
+        add_action('wp_ajax_wc_licensed_product_delete_version', [$this, 'ajaxDeleteVersion']);
+        add_action('wp_ajax_wc_licensed_product_toggle_version', [$this, 'ajaxToggleVersion']);
+
+        // Enqueue scripts for product edit page
+        add_action('admin_enqueue_scripts', [$this, 'enqueueScripts']);
+    }
+
+    /**
+     * Add versions meta box to product edit page
+     */
+    public function addVersionsMetaBox(): void
+    {
+        add_meta_box(
+            'wc_licensed_product_versions',
+            __('Product Versions', 'wc-licensed-product'),
+            [$this, 'renderVersionsMetaBox'],
+            'product',
+            'normal',
+            'high'
+        );
+    }
+
+    /**
+     * Render versions meta box
+     */
+    public function renderVersionsMetaBox(\WP_Post $post): void
+    {
+        $product = wc_get_product($post->ID);
+        if (!$product || !$product->is_type('licensed')) {
+            echo '<p>' . esc_html__('This meta box is only available for Licensed Products.', 'wc-licensed-product') . '</p>';
+            return;
+        }
+
+        $versions = $this->versionManager->getVersionsByProduct($post->ID);
+        wp_nonce_field('wc_licensed_product_versions', 'wc_licensed_product_versions_nonce');
+        ?>
+        <div class="wc-licensed-product-versions">
+            <div class="versions-add-form">
+                <h4><?php esc_html_e('Add New Version', 'wc-licensed-product'); ?></h4>
+                <table class="form-table">
+                    <tr>
+                        <th><label for="new_version"><?php esc_html_e('Version', 'wc-licensed-product'); ?></label></th>
+                        <td>
+                            <input type="text" id="new_version" name="new_version" placeholder="1.0.0" class="regular-text" pattern="[0-9]+\.[0-9]+\.[0-9]+" />
+                            <p class="description"><?php esc_html_e('Use semantic versioning (e.g., 1.0.0)', 'wc-licensed-product'); ?></p>
+                        </td>
+                    </tr>
+                    <tr>
+                        <th><label for="new_download_url"><?php esc_html_e('Download URL', 'wc-licensed-product'); ?></label></th>
+                        <td>
+                            <input type="url" id="new_download_url" name="new_download_url" class="large-text" placeholder="https://" />
+                            <p class="description"><?php esc_html_e('URL to the downloadable file for this version.', 'wc-licensed-product'); ?></p>
+                        </td>
+                    </tr>
+                    <tr>
+                        <th><label for="new_release_notes"><?php esc_html_e('Release Notes', 'wc-licensed-product'); ?></label></th>
+                        <td>
+                            <textarea id="new_release_notes" name="new_release_notes" rows="3" class="large-text"></textarea>
+                        </td>
+                    </tr>
+                </table>
+                <p>
+                    <button type="button" class="button button-primary" id="add-version-btn" data-product-id="<?php echo esc_attr($post->ID); ?>">
+                        <?php esc_html_e('Add Version', 'wc-licensed-product'); ?>
+                    </button>
+                    <span class="spinner" style="float: none;"></span>
+                </p>
+            </div>
+
+            <hr />
+
+            <h4><?php esc_html_e('Existing Versions', 'wc-licensed-product'); ?></h4>
+            <table class="wp-list-table widefat fixed striped" id="versions-table">
+                <thead>
+                    <tr>
+                        <th><?php esc_html_e('Version', 'wc-licensed-product'); ?></th>
+                        <th><?php esc_html_e('Download URL', 'wc-licensed-product'); ?></th>
+                        <th><?php esc_html_e('Release Notes', 'wc-licensed-product'); ?></th>
+                        <th><?php esc_html_e('Status', 'wc-licensed-product'); ?></th>
+                        <th><?php esc_html_e('Released', 'wc-licensed-product'); ?></th>
+                        <th><?php esc_html_e('Actions', 'wc-licensed-product'); ?></th>
+                    </tr>
+                </thead>
+                <tbody>
+                    <?php if (empty($versions)): ?>
+                        <tr class="no-versions">
+                            <td colspan="6"><?php esc_html_e('No versions found. Add your first version above.', 'wc-licensed-product'); ?></td>
+                        </tr>
+                    <?php else: ?>
+                        <?php foreach ($versions as $version): ?>
+                            <tr data-version-id="<?php echo esc_attr($version->getId()); ?>">
+                                <td><strong><?php echo esc_html($version->getVersion()); ?></strong></td>
+                                <td>
+                                    <?php if ($version->getDownloadUrl()): ?>
+                                        <a href="<?php echo esc_url($version->getDownloadUrl()); ?>" target="_blank">
+                                            <?php echo esc_html(wp_basename($version->getDownloadUrl())); ?>
+                                        </a>
+                                    <?php else: ?>
+                                        <em><?php esc_html_e('No download URL', 'wc-licensed-product'); ?></em>
+                                    <?php endif; ?>
+                                </td>
+                                <td><?php echo esc_html($version->getReleaseNotes() ? wp_trim_words($version->getReleaseNotes(), 10) : '—'); ?></td>
+                                <td>
+                                    <span class="version-status version-status-<?php echo $version->isActive() ? 'active' : 'inactive'; ?>">
+                                        <?php echo $version->isActive() ? esc_html__('Active', 'wc-licensed-product') : esc_html__('Inactive', 'wc-licensed-product'); ?>
+                                    </span>
+                                </td>
+                                <td><?php echo esc_html($version->getReleasedAt()->format(get_option('date_format'))); ?></td>
+                                <td>
+                                    <button type="button" class="button button-small toggle-version-btn" data-version-id="<?php echo esc_attr($version->getId()); ?>" data-active="<?php echo $version->isActive() ? '1' : '0'; ?>">
+                                        <?php echo $version->isActive() ? esc_html__('Deactivate', 'wc-licensed-product') : esc_html__('Activate', 'wc-licensed-product'); ?>
+                                    </button>
+                                    <button type="button" class="button button-small button-link-delete delete-version-btn" data-version-id="<?php echo esc_attr($version->getId()); ?>">
+                                        <?php esc_html_e('Delete', 'wc-licensed-product'); ?>
+                                    </button>
+                                </td>
+                            </tr>
+                        <?php endforeach; ?>
+                    <?php endif; ?>
+                </tbody>
+            </table>
+        </div>
+        <?php
+    }
+
+    /**
+     * Enqueue scripts for product edit page
+     */
+    public function enqueueScripts(string $hook): void
+    {
+        if ($hook !== 'post.php' && $hook !== 'post-new.php') {
+            return;
+        }
+
+        global $post;
+        if (!$post || $post->post_type !== 'product') {
+            return;
+        }
+
+        wp_enqueue_script(
+            'wc-licensed-product-versions',
+            WC_LICENSED_PRODUCT_PLUGIN_URL . 'assets/js/versions.js',
+            ['jquery'],
+            WC_LICENSED_PRODUCT_VERSION,
+            true
+        );
+
+        wp_localize_script('wc-licensed-product-versions', 'wcLicensedProductVersions', [
+            'ajaxUrl' => admin_url('admin-ajax.php'),
+            'nonce' => wp_create_nonce('wc_licensed_product_versions'),
+            'strings' => [
+                'confirmDelete' => __('Are you sure you want to delete this version?', 'wc-licensed-product'),
+                'versionRequired' => __('Please enter a version number.', 'wc-licensed-product'),
+                'versionInvalid' => __('Please enter a valid version number (e.g., 1.0.0).', 'wc-licensed-product'),
+                'error' => __('An error occurred. Please try again.', 'wc-licensed-product'),
+            ],
+        ]);
+
+        wp_enqueue_style(
+            'wc-licensed-product-admin',
+            WC_LICENSED_PRODUCT_PLUGIN_URL . 'assets/css/admin.css',
+            [],
+            WC_LICENSED_PRODUCT_VERSION
+        );
+    }
+
+    /**
+     * AJAX handler for adding a version
+     */
+    public function ajaxAddVersion(): void
+    {
+        check_ajax_referer('wc_licensed_product_versions', 'nonce');
+
+        if (!current_user_can('manage_woocommerce')) {
+            wp_send_json_error(['message' => __('Permission denied.', 'wc-licensed-product')]);
+        }
+
+        $productId = absint($_POST['product_id'] ?? 0);
+        $version = sanitize_text_field($_POST['version'] ?? '');
+        $downloadUrl = esc_url_raw($_POST['download_url'] ?? '');
+        $releaseNotes = sanitize_textarea_field($_POST['release_notes'] ?? '');
+
+        if (!$productId || !$version) {
+            wp_send_json_error(['message' => __('Product ID and version are required.', 'wc-licensed-product')]);
+        }
+
+        // Validate version format
+        if (!preg_match('/^\d+\.\d+\.\d+$/', $version)) {
+            wp_send_json_error(['message' => __('Invalid version format. Use semantic versioning (e.g., 1.0.0).', 'wc-licensed-product')]);
+        }
+
+        // Check if version already exists
+        if ($this->versionManager->versionExists($productId, $version)) {
+            wp_send_json_error(['message' => __('This version already exists.', 'wc-licensed-product')]);
+        }
+
+        $newVersion = $this->versionManager->createVersion(
+            $productId,
+            $version,
+            $releaseNotes ?: null,
+            $downloadUrl ?: null
+        );
+
+        if (!$newVersion) {
+            wp_send_json_error(['message' => __('Failed to create version.', 'wc-licensed-product')]);
+        }
+
+        // Also update the product's current version meta
+        update_post_meta($productId, '_licensed_current_version', $version);
+
+        wp_send_json_success([
+            'message' => __('Version added successfully.', 'wc-licensed-product'),
+            'version' => $newVersion->toArray(),
+            'html' => $this->getVersionRowHtml($newVersion),
+        ]);
+    }
+
+    /**
+     * AJAX handler for deleting a version
+     */
+    public function ajaxDeleteVersion(): void
+    {
+        check_ajax_referer('wc_licensed_product_versions', 'nonce');
+
+        if (!current_user_can('manage_woocommerce')) {
+            wp_send_json_error(['message' => __('Permission denied.', 'wc-licensed-product')]);
+        }
+
+        $versionId = absint($_POST['version_id'] ?? 0);
+
+        if (!$versionId) {
+            wp_send_json_error(['message' => __('Version ID is required.', 'wc-licensed-product')]);
+        }
+
+        $result = $this->versionManager->deleteVersion($versionId);
+
+        if (!$result) {
+            wp_send_json_error(['message' => __('Failed to delete version.', 'wc-licensed-product')]);
+        }
+
+        wp_send_json_success(['message' => __('Version deleted successfully.', 'wc-licensed-product')]);
+    }
+
+    /**
+     * AJAX handler for toggling version status
+     */
+    public function ajaxToggleVersion(): void
+    {
+        check_ajax_referer('wc_licensed_product_versions', 'nonce');
+
+        if (!current_user_can('manage_woocommerce')) {
+            wp_send_json_error(['message' => __('Permission denied.', 'wc-licensed-product')]);
+        }
+
+        $versionId = absint($_POST['version_id'] ?? 0);
+        $currentlyActive = (bool) ($_POST['currently_active'] ?? false);
+
+        if (!$versionId) {
+            wp_send_json_error(['message' => __('Version ID is required.', 'wc-licensed-product')]);
+        }
+
+        $result = $this->versionManager->updateVersion($versionId, null, null, !$currentlyActive);
+
+        if (!$result) {
+            wp_send_json_error(['message' => __('Failed to update version.', 'wc-licensed-product')]);
+        }
+
+        wp_send_json_success([
+            'message' => __('Version updated successfully.', 'wc-licensed-product'),
+            'isActive' => !$currentlyActive,
+        ]);
+    }
+
+    /**
+     * Get HTML for a version table row
+     */
+    private function getVersionRowHtml(\Jeremias\WcLicensedProduct\Product\ProductVersion $version): string
+    {
+        ob_start();
+        ?>
+        <tr data-version-id="<?php echo esc_attr($version->getId()); ?>">
+            <td><strong><?php echo esc_html($version->getVersion()); ?></strong></td>
+            <td>
+                <?php if ($version->getDownloadUrl()): ?>
+                    <a href="<?php echo esc_url($version->getDownloadUrl()); ?>" target="_blank">
+                        <?php echo esc_html(wp_basename($version->getDownloadUrl())); ?>
+                    </a>
+                <?php else: ?>
+                    <em><?php esc_html_e('No download URL', 'wc-licensed-product'); ?></em>
+                <?php endif; ?>
+            </td>
+            <td><?php echo esc_html($version->getReleaseNotes() ? wp_trim_words($version->getReleaseNotes(), 10) : '—'); ?></td>
+            <td>
+                <span class="version-status version-status-<?php echo $version->isActive() ? 'active' : 'inactive'; ?>">
+                    <?php echo $version->isActive() ? esc_html__('Active', 'wc-licensed-product') : esc_html__('Inactive', 'wc-licensed-product'); ?>
+                </span>
+            </td>
+            <td><?php echo esc_html($version->getReleasedAt()->format(get_option('date_format'))); ?></td>
+            <td>
+                <button type="button" class="button button-small toggle-version-btn" data-version-id="<?php echo esc_attr($version->getId()); ?>" data-active="<?php echo $version->isActive() ? '1' : '0'; ?>">
+                    <?php echo $version->isActive() ? esc_html__('Deactivate', 'wc-licensed-product') : esc_html__('Activate', 'wc-licensed-product'); ?>
+                </button>
+                <button type="button" class="button button-small button-link-delete delete-version-btn" data-version-id="<?php echo esc_attr($version->getId()); ?>">
+                    <?php esc_html_e('Delete', 'wc-licensed-product'); ?>
+                </button>
+            </td>
+        </tr>
+        <?php
+        return ob_get_clean();
+    }
+}

src/Api/RestApiController.php

@@ -21,6 +21,16 @@ final class RestApiController
 {
     private const NAMESPACE = 'wc-licensed-product/v1';
 
+    /**
+     * Rate limit: requests per minute per IP
+     */
+    private const RATE_LIMIT_REQUESTS = 30;
+
+    /**
+     * Rate limit window in seconds
+     */
+    private const RATE_LIMIT_WINDOW = 60;
+
     private LicenseManager $licenseManager;
 
     public function __construct(LicenseManager $licenseManager)
@@ -37,6 +47,77 @@ final class RestApiController
         add_action('rest_api_init', [$this, 'registerRoutes']);
     }
 
+    /**
+     * Check rate limit for current IP
+     *
+     * @return WP_REST_Response|null Returns error response if rate limited, null if OK
+     */
+    private function checkRateLimit(): ?WP_REST_Response
+    {
+        $ip = $this->getClientIp();
+        $transientKey = 'wclp_rate_' . md5($ip);
+
+        $data = get_transient($transientKey);
+
+        if ($data === false) {
+            // First request, start counting
+            set_transient($transientKey, ['count' => 1, 'start' => time()], self::RATE_LIMIT_WINDOW);
+            return null;
+        }
+
+        $count = (int) ($data['count'] ?? 0);
+        $start = (int) ($data['start'] ?? time());
+
+        // Check if window has expired
+        if (time() - $start >= self::RATE_LIMIT_WINDOW) {
+            // Reset counter
+            set_transient($transientKey, ['count' => 1, 'start' => time()], self::RATE_LIMIT_WINDOW);
+            return null;
+        }
+
+        // Check if limit exceeded
+        if ($count >= self::RATE_LIMIT_REQUESTS) {
+            $retryAfter = self::RATE_LIMIT_WINDOW - (time() - $start);
+            $response = new WP_REST_Response([
+                'success' => false,
+                'error' => 'rate_limit_exceeded',
+                'message' => __('Too many requests. Please try again later.', 'wc-licensed-product'),
+                'retry_after' => $retryAfter,
+            ], 429);
+            $response->header('Retry-After', (string) $retryAfter);
+            return $response;
+        }
+
+        // Increment counter
+        set_transient($transientKey, ['count' => $count + 1, 'start' => $start], self::RATE_LIMIT_WINDOW);
+        return null;
+    }
+
+    /**
+     * Get client IP address
+     */
+    private function getClientIp(): string
+    {
+        $headers = [
+            'HTTP_CF_CONNECTING_IP', // Cloudflare
+            'HTTP_X_FORWARDED_FOR',
+            'HTTP_X_REAL_IP',
+            'REMOTE_ADDR',
+        ];
+
+        foreach ($headers as $header) {
+            if (!empty($_SERVER[$header])) {
+                $ips = explode(',', $_SERVER[$header]);
+                $ip = trim($ips[0]);
+                if (filter_var($ip, FILTER_VALIDATE_IP)) {
+                    return $ip;
+                }
+            }
+        }
+
+        return '0.0.0.0';
+    }
+
     /**
      * Register REST API routes
      */
@@ -125,6 +206,11 @@ final class RestApiController
      */
     public function validateLicense(WP_REST_Request $request): WP_REST_Response
     {
+        $rateLimitResponse = $this->checkRateLimit();
+        if ($rateLimitResponse !== null) {
+            return $rateLimitResponse;
+        }
+
         $licenseKey = $request->get_param('license_key');
         $domain = $request->get_param('domain');
 
@@ -140,6 +226,11 @@ final class RestApiController
      */
     public function checkStatus(WP_REST_Request $request): WP_REST_Response
     {
+        $rateLimitResponse = $this->checkRateLimit();
+        if ($rateLimitResponse !== null) {
+            return $rateLimitResponse;
+        }
+
         $licenseKey = $request->get_param('license_key');
         $license = $this->licenseManager->getLicenseByKey($licenseKey);
 
@@ -166,6 +257,11 @@ final class RestApiController
      */
     public function activateLicense(WP_REST_Request $request): WP_REST_Response
     {
+        $rateLimitResponse = $this->checkRateLimit();
+        if ($rateLimitResponse !== null) {
+            return $rateLimitResponse;
+        }
+
         $licenseKey = $request->get_param('license_key');
         $domain = $request->get_param('domain');
 
@@ -228,6 +324,11 @@ final class RestApiController
      */
     public function deactivateLicense(WP_REST_Request $request): WP_REST_Response
     {
+        $rateLimitResponse = $this->checkRateLimit();
+        if ($rateLimitResponse !== null) {
+            return $rateLimitResponse;
+        }
+
         $licenseKey = $request->get_param('license_key');
         $domain = $request->get_param('domain');
 

src/Email/LicenseEmailController.php

@@ -0,0 +1,198 @@
+<?php
+/**
+ * License Email Controller
+ *
+ * @package Jeremias\WcLicensedProduct\Email
+ */
+
+declare(strict_types=1);
+
+namespace Jeremias\WcLicensedProduct\Email;
+
+use Jeremias\WcLicensedProduct\License\LicenseManager;
+
+/**
+ * Handles email notifications for licenses
+ */
+final class LicenseEmailController
+{
+    private LicenseManager $licenseManager;
+
+    public function __construct(LicenseManager $licenseManager)
+    {
+        $this->licenseManager = $licenseManager;
+        $this->registerHooks();
+    }
+
+    /**
+     * Register WordPress hooks
+     */
+    private function registerHooks(): void
+    {
+        // Add license info to order completed email
+        add_action('woocommerce_email_after_order_table', [$this, 'addLicenseInfoToEmail'], 20, 4);
+
+        // Add license info to order details in emails
+        add_action('woocommerce_order_item_meta_end', [$this, 'addLicenseToOrderItem'], 10, 4);
+    }
+
+    /**
+     * Add license information to order completed email
+     */
+    public function addLicenseInfoToEmail(\WC_Order $order, bool $sentToAdmin, bool $plainText, $email): void
+    {
+        // Only add to completed order email sent to customer
+        if ($sentToAdmin || !$email || $email->id !== 'customer_completed_order') {
+            return;
+        }
+
+        $licenses = $this->getLicensesForOrder($order);
+        if (empty($licenses)) {
+            return;
+        }
+
+        if ($plainText) {
+            $this->renderPlainTextLicenseInfo($licenses, $order);
+        } else {
+            $this->renderHtmlLicenseInfo($licenses, $order);
+        }
+    }
+
+    /**
+     * Add license key to order item in email
+     */
+    public function addLicenseToOrderItem(int $itemId, \WC_Order_Item $item, \WC_Order $order, bool $plainText): void
+    {
+        $product = $item->get_product();
+        if (!$product || !$product->is_type('licensed')) {
+            return;
+        }
+
+        $license = $this->licenseManager->getLicenseByOrderAndProduct($order->get_id(), $product->get_id());
+        if (!$license) {
+            return;
+        }
+
+        if ($plainText) {
+            echo "\n" . esc_html__('License Key:', 'wc-licensed-product') . ' ' . esc_html($license->getLicenseKey()) . "\n";
+        } else {
+            ?>
+            <div style="margin-top: 10px; padding: 10px; background-color: #f8f9fa; border-left: 3px solid #0073aa;">
+                <strong><?php esc_html_e('License Key:', 'wc-licensed-product'); ?></strong>
+                <code style="display: block; margin-top: 5px; padding: 5px; background: #fff; font-family: monospace;">
+                    <?php echo esc_html($license->getLicenseKey()); ?>
+                </code>
+            </div>
+            <?php
+        }
+    }
+
+    /**
+     * Get all licenses for an order
+     */
+    private function getLicensesForOrder(\WC_Order $order): array
+    {
+        $licenses = [];
+
+        foreach ($order->get_items() as $item) {
+            $product = $item->get_product();
+            if ($product && $product->is_type('licensed')) {
+                $license = $this->licenseManager->getLicenseByOrderAndProduct($order->get_id(), $product->get_id());
+                if ($license) {
+                    $licenses[] = [
+                        'license' => $license,
+                        'product_name' => $product->get_name(),
+                    ];
+                }
+            }
+        }
+
+        return $licenses;
+    }
+
+    /**
+     * Render license info in HTML format
+     */
+    private function renderHtmlLicenseInfo(array $licenses, \WC_Order $order): void
+    {
+        $domain = $order->get_meta('_licensed_product_domain');
+        ?>
+        <div style="margin: 20px 0; padding: 20px; background-color: #f8f9fa; border: 1px solid #e5e5e5; border-radius: 4px;">
+            <h2 style="margin-top: 0; color: #333;"><?php esc_html_e('Your License Keys', 'wc-licensed-product'); ?></h2>
+
+            <?php if ($domain): ?>
+                <p style="margin-bottom: 15px;">
+                    <strong><?php esc_html_e('Licensed Domain:', 'wc-licensed-product'); ?></strong>
+                    <?php echo esc_html($domain); ?>
+                </p>
+            <?php endif; ?>
+
+            <table style="width: 100%; border-collapse: collapse;">
+                <thead>
+                    <tr>
+                        <th style="text-align: left; padding: 10px; border-bottom: 2px solid #ddd;"><?php esc_html_e('Product', 'wc-licensed-product'); ?></th>
+                        <th style="text-align: left; padding: 10px; border-bottom: 2px solid #ddd;"><?php esc_html_e('License Key', 'wc-licensed-product'); ?></th>
+                        <th style="text-align: left; padding: 10px; border-bottom: 2px solid #ddd;"><?php esc_html_e('Expires', 'wc-licensed-product'); ?></th>
+                    </tr>
+                </thead>
+                <tbody>
+                    <?php foreach ($licenses as $item): ?>
+                        <tr>
+                            <td style="padding: 10px; border-bottom: 1px solid #eee;"><?php echo esc_html($item['product_name']); ?></td>
+                            <td style="padding: 10px; border-bottom: 1px solid #eee;">
+                                <code style="background: #fff; padding: 3px 6px; font-family: monospace;">
+                                    <?php echo esc_html($item['license']->getLicenseKey()); ?>
+                                </code>
+                            </td>
+                            <td style="padding: 10px; border-bottom: 1px solid #eee;">
+                                <?php
+                                $expiresAt = $item['license']->getExpiresAt();
+                                echo $expiresAt
+                                    ? esc_html($expiresAt->format(get_option('date_format')))
+                                    : esc_html__('Never', 'wc-licensed-product');
+                                ?>
+                            </td>
+                        </tr>
+                    <?php endforeach; ?>
+                </tbody>
+            </table>
+
+            <p style="margin-top: 15px; margin-bottom: 0; font-size: 0.9em; color: #666;">
+                <?php esc_html_e('You can also view your licenses in your account under "Licenses".', 'wc-licensed-product'); ?>
+            </p>
+        </div>
+        <?php
+    }
+
+    /**
+     * Render license info in plain text format
+     */
+    private function renderPlainTextLicenseInfo(array $licenses, \WC_Order $order): void
+    {
+        $domain = $order->get_meta('_licensed_product_domain');
+
+        echo "\n\n";
+        echo "==========================================================\n";
+        echo esc_html__('YOUR LICENSE KEYS', 'wc-licensed-product') . "\n";
+        echo "==========================================================\n\n";
+
+        if ($domain) {
+            echo esc_html__('Licensed Domain:', 'wc-licensed-product') . ' ' . esc_html($domain) . "\n\n";
+        }
+
+        foreach ($licenses as $item) {
+            echo esc_html($item['product_name']) . "\n";
+            echo esc_html__('License Key:', 'wc-licensed-product') . ' ' . esc_html($item['license']->getLicenseKey()) . "\n";
+
+            $expiresAt = $item['license']->getExpiresAt();
+            echo esc_html__('Expires:', 'wc-licensed-product') . ' ';
+            echo $expiresAt
+                ? esc_html($expiresAt->format(get_option('date_format')))
+                : esc_html__('Never', 'wc-licensed-product');
+            echo "\n\n";
+        }
+
+        echo esc_html__('You can also view your licenses in your account under "Licenses".', 'wc-licensed-product') . "\n";
+        echo "==========================================================\n\n";
+    }
+}

src/Plugin.php

@@ -10,11 +10,14 @@ declare(strict_types=1);
 namespace Jeremias\WcLicensedProduct;
 
 use Jeremias\WcLicensedProduct\Admin\AdminController;
+use Jeremias\WcLicensedProduct\Admin\VersionAdminController;
 use Jeremias\WcLicensedProduct\Api\RestApiController;
 use Jeremias\WcLicensedProduct\Checkout\CheckoutController;
+use Jeremias\WcLicensedProduct\Email\LicenseEmailController;
 use Jeremias\WcLicensedProduct\Frontend\AccountController;
 use Jeremias\WcLicensedProduct\License\LicenseManager;
 use Jeremias\WcLicensedProduct\Product\LicensedProductType;
+use Jeremias\WcLicensedProduct\Product\VersionManager;
 use Twig\Environment;
 use Twig\Loader\FilesystemLoader;
 
@@ -38,6 +41,11 @@ final class Plugin
      */
     private LicenseManager $licenseManager;
 
+    /**
+     * Version manager
+     */
+    private VersionManager $versionManager;
+
     /**
      * Get singleton instance
      */
@@ -90,15 +98,18 @@ final class Plugin
     private function initComponents(): void
     {
         $this->licenseManager = new LicenseManager();
+        $this->versionManager = new VersionManager();
 
         // Initialize controllers
         new LicensedProductType();
         new CheckoutController($this->licenseManager);
         new AccountController($this->twig, $this->licenseManager);
         new RestApiController($this->licenseManager);
+        new LicenseEmailController($this->licenseManager);
 
         if (is_admin()) {
             new AdminController($this->twig, $this->licenseManager);
+            new VersionAdminController($this->versionManager);
         }
     }
 

src/Product/ProductVersion.php

@@ -0,0 +1,137 @@
+<?php
+/**
+ * Product Version Model
+ *
+ * @package Jeremias\WcLicensedProduct\Product
+ */
+
+declare(strict_types=1);
+
+namespace Jeremias\WcLicensedProduct\Product;
+
+/**
+ * Product version entity model
+ */
+class ProductVersion
+{
+    private int $id;
+    private int $productId;
+    private string $version;
+    private int $majorVersion;
+    private int $minorVersion;
+    private int $patchVersion;
+    private ?string $releaseNotes;
+    private ?string $downloadUrl;
+    private bool $isActive;
+    private \DateTimeInterface $releasedAt;
+    private \DateTimeInterface $createdAt;
+
+    /**
+     * Create version from database row
+     */
+    public static function fromArray(array $data): self
+    {
+        $version = new self();
+        $version->id = (int) $data['id'];
+        $version->productId = (int) $data['product_id'];
+        $version->version = $data['version'];
+        $version->majorVersion = (int) $data['major_version'];
+        $version->minorVersion = (int) $data['minor_version'];
+        $version->patchVersion = (int) $data['patch_version'];
+        $version->releaseNotes = $data['release_notes'] ?: null;
+        $version->downloadUrl = $data['download_url'] ?: null;
+        $version->isActive = (bool) $data['is_active'];
+        $version->releasedAt = new \DateTimeImmutable($data['released_at']);
+        $version->createdAt = new \DateTimeImmutable($data['created_at']);
+
+        return $version;
+    }
+
+    /**
+     * Parse version string into components
+     */
+    public static function parseVersion(string $versionString): array
+    {
+        $parts = explode('.', $versionString);
+        return [
+            'major' => (int) ($parts[0] ?? 0),
+            'minor' => (int) ($parts[1] ?? 0),
+            'patch' => (int) ($parts[2] ?? 0),
+        ];
+    }
+
+    public function getId(): int
+    {
+        return $this->id;
+    }
+
+    public function getProductId(): int
+    {
+        return $this->productId;
+    }
+
+    public function getVersion(): string
+    {
+        return $this->version;
+    }
+
+    public function getMajorVersion(): int
+    {
+        return $this->majorVersion;
+    }
+
+    public function getMinorVersion(): int
+    {
+        return $this->minorVersion;
+    }
+
+    public function getPatchVersion(): int
+    {
+        return $this->patchVersion;
+    }
+
+    public function getReleaseNotes(): ?string
+    {
+        return $this->releaseNotes;
+    }
+
+    public function getDownloadUrl(): ?string
+    {
+        return $this->downloadUrl;
+    }
+
+    public function isActive(): bool
+    {
+        return $this->isActive;
+    }
+
+    public function getReleasedAt(): \DateTimeInterface
+    {
+        return $this->releasedAt;
+    }
+
+    public function getCreatedAt(): \DateTimeInterface
+    {
+        return $this->createdAt;
+    }
+
+    /**
+     * Convert to array
+     */
+    public function toArray(): array
+    {
+        return [
+            'id' => $this->id,
+            'product_id' => $this->productId,
+            'version' => $this->version,
+            'major_version' => $this->majorVersion,
+            'minor_version' => $this->minorVersion,
+            'patch_version' => $this->patchVersion,
+            'release_notes' => $this->releaseNotes,
+            'download_url' => $this->downloadUrl,
+            'is_active' => $this->isActive,
+            'released_at' => $this->releasedAt->format('Y-m-d H:i:s'),
+            'created_at' => $this->createdAt->format('Y-m-d H:i:s'),
+        ];
+    }
+}

src/Product/VersionManager.php

@@ -0,0 +1,209 @@
+<?php
+/**
+ * Version Manager
+ *
+ * @package Jeremias\WcLicensedProduct\Product
+ */
+
+declare(strict_types=1);
+
+namespace Jeremias\WcLicensedProduct\Product;
+
+use Jeremias\WcLicensedProduct\Installer;
+
+/**
+ * Manages product versions (CRUD operations)
+ */
+class VersionManager
+{
+    /**
+     * Get version by ID
+     */
+    public function getVersionById(int $id): ?ProductVersion
+    {
+        global $wpdb;
+
+        $tableName = Installer::getVersionsTable();
+        $row = $wpdb->get_row(
+            $wpdb->prepare("SELECT * FROM {$tableName} WHERE id = %d", $id),
+            ARRAY_A
+        );
+
+        return $row ? ProductVersion::fromArray($row) : null;
+    }
+
+    /**
+     * Get all versions for a product
+     */
+    public function getVersionsByProduct(int $productId): array
+    {
+        global $wpdb;
+
+        $tableName = Installer::getVersionsTable();
+        $rows = $wpdb->get_results(
+            $wpdb->prepare(
+                "SELECT * FROM {$tableName} WHERE product_id = %d ORDER BY major_version DESC, minor_version DESC, patch_version DESC",
+                $productId
+            ),
+            ARRAY_A
+        );
+
+        return array_map(fn(array $row) => ProductVersion::fromArray($row), $rows ?: []);
+    }
+
+    /**
+     * Get latest active version for a product
+     */
+    public function getLatestVersion(int $productId): ?ProductVersion
+    {
+        global $wpdb;
+
+        $tableName = Installer::getVersionsTable();
+        $row = $wpdb->get_row(
+            $wpdb->prepare(
+                "SELECT * FROM {$tableName} WHERE product_id = %d AND is_active = 1 ORDER BY major_version DESC, minor_version DESC, patch_version DESC LIMIT 1",
+                $productId
+            ),
+            ARRAY_A
+        );
+
+        return $row ? ProductVersion::fromArray($row) : null;
+    }
+
+    /**
+     * Get latest version for a specific major version
+     */
+    public function getLatestVersionForMajor(int $productId, int $majorVersion): ?ProductVersion
+    {
+        global $wpdb;
+
+        $tableName = Installer::getVersionsTable();
+        $row = $wpdb->get_row(
+            $wpdb->prepare(
+                "SELECT * FROM {$tableName} WHERE product_id = %d AND major_version = %d AND is_active = 1 ORDER BY minor_version DESC, patch_version DESC LIMIT 1",
+                $productId,
+                $majorVersion
+            ),
+            ARRAY_A
+        );
+
+        return $row ? ProductVersion::fromArray($row) : null;
+    }
+
+    /**
+     * Create a new version
+     */
+    public function createVersion(
+        int $productId,
+        string $version,
+        ?string $releaseNotes = null,
+        ?string $downloadUrl = null
+    ): ?ProductVersion {
+        global $wpdb;
+
+        $parsed = ProductVersion::parseVersion($version);
+
+        $tableName = Installer::getVersionsTable();
+        $result = $wpdb->insert(
+            $tableName,
+            [
+                'product_id' => $productId,
+                'version' => $version,
+                'major_version' => $parsed['major'],
+                'minor_version' => $parsed['minor'],
+                'patch_version' => $parsed['patch'],
+                'release_notes' => $releaseNotes,
+                'download_url' => $downloadUrl,
+                'is_active' => 1,
+            ],
+            ['%d', '%s', '%d', '%d', '%d', '%s', '%s', '%d']
+        );
+
+        if ($result === false) {
+            return null;
+        }
+
+        return $this->getVersionById((int) $wpdb->insert_id);
+    }
+
+    /**
+     * Update a version
+     */
+    public function updateVersion(
+        int $versionId,
+        ?string $releaseNotes = null,
+        ?string $downloadUrl = null,
+        ?bool $isActive = null
+    ): bool {
+        global $wpdb;
+
+        $data = [];
+        $formats = [];
+
+        if ($releaseNotes !== null) {
+            $data['release_notes'] = $releaseNotes;
+            $formats[] = '%s';
+        }
+
+        if ($downloadUrl !== null) {
+            $data['download_url'] = $downloadUrl;
+            $formats[] = '%s';
+        }
+
+        if ($isActive !== null) {
+            $data['is_active'] = $isActive ? 1 : 0;
+            $formats[] = '%d';
+        }
+
+        if (empty($data)) {
+            return true;
+        }
+
+        $tableName = Installer::getVersionsTable();
+        $result = $wpdb->update(
+            $tableName,
+            $data,
+            ['id' => $versionId],
+            $formats,
+            ['%d']
+        );
+
+        return $result !== false;
+    }
+
+    /**
+     * Delete a version
+     */
+    public function deleteVersion(int $versionId): bool
+    {
+        global $wpdb;
+
+        $tableName = Installer::getVersionsTable();
+        $result = $wpdb->delete(
+            $tableName,
+            ['id' => $versionId],
+            ['%d']
+        );
+
+        return $result !== false;
+    }
+
+    /**
+     * Check if version exists for product
+     */
+    public function versionExists(int $productId, string $version): bool
+    {
+        global $wpdb;
+
+        $tableName = Installer::getVersionsTable();
+        $count = $wpdb->get_var(
+            $wpdb->prepare(
+                "SELECT COUNT(*) FROM {$tableName} WHERE product_id = %d AND version = %s",
+                $productId,
+                $version
+            )
+        );
+
+        return (int) $count > 0;
+    }
+}

wc-licensed-product.php

@@ -3,7 +3,7 @@
  * Plugin Name: WooCommerce Licensed Product
  * Plugin URI: https://src.bundespruefstelle.ch/magdev/wc-licensed-product
  * Description: WooCommerce plugin to sell software products using license keys with domain-based validation.
- * Version: 0.0.1
+ * Version: 0.0.2
  * Author: Marco Graetsch
  * Author URI: https://src.bundespruefstelle.ch/magdev
  * License: GPL-2.0-or-later
@@ -28,7 +28,7 @@ if (!defined('ABSPATH')) {
 }
 
 // Plugin constants
-define('WC_LICENSED_PRODUCT_VERSION', '0.0.1');
+define('WC_LICENSED_PRODUCT_VERSION', '0.0.2');
 define('WC_LICENSED_PRODUCT_PLUGIN_FILE', __FILE__);
 define('WC_LICENSED_PRODUCT_PLUGIN_DIR', plugin_dir_path(__FILE__));
 define('WC_LICENSED_PRODUCT_PLUGIN_URL', plugin_dir_url(__FILE__));