Semantic Vector Search for WooCommerce Products

<?php
declare(strict_types=1);

/**
* Author: Artur Yusupov (Fullstack Agentic Lab)
* Package: @agentic-lab/semantic-search
* Module: SemanticProductSearchService
* Standard: WooCommerce HPOS / Action Scheduler / PHP 8.4 Strict
*/

namespace AgenticLab\Search;

use WC_Product;
use WP_REST_Request;
use WP_REST_Response;
use WP_Error;
use Throwable;

final class SemanticProductSearchService
{
  private string $vectorDbHost;
  private string $openAiKey;
  private const COLLECTION_NAME = 'woocommerce_products';

  public function __construct()
  {
      $this->vectorDbHost = (string) (getenv('QDRANT_HOST') ?: 'http://127.0.0.1:6333');
      $this->openAiKey    = (string) (getenv('OPENAI_API_KEY') ?: '');
  }

  public function init(): void
  {
      // 1. Асинхронный триггер при обновлении товара WooCommerce
      add_action('woocommerce_update_product', [$this, 'scheduleProductIndexation'], 10, 1);
      add_action('woocommerce_new_product', [$this, 'scheduleProductIndexation'], 10, 1);

      // 2. Обработчик задачи в очереди Action Scheduler
      add_action('agentic_index_product_vector_task', [$this, 'processProductIndexation'], 10, 1);

      // 3. Регистрация поискового REST API маршрута
      add_action('rest_api_init', [$this, 'registerSearchRoute']);
  }

  public function scheduleProductIndexation(int $productId): void
  {
      if (function_exists('as_enqueue_async_action')) {
          as_enqueue_async_action(
              'agentic_index_product_vector_task',
              ['product_id' => $productId],
              'agentic-search-sync'
          );
      }
  }

  public function processProductIndexation(int $productId): void
  {
      $product = wc_get_product($productId);

      if (!$product instanceof WC_Product || $product->get_status() !== 'publish') {
          // Если товар скрыт или удален — удаляем вектор из базы
          $this->deleteVectorFromDb($productId);
          return;
      }

      // Формирование богатого контекста товара
      $context = $this->buildProductContext($product);

      // Получение числового вектора
      $vector = $this->generateEmbedding($context);

      if ($vector === null) {
          error_log("[SemanticSearch] Не удалось сгенерировать вектор для товара #{$productId}");
          return;
      }

      // Сохранение в коллекцию векторной БД с метаданными фильтрации
      $this->upsertVectorToDb($productId, $vector, [
          'product_id'   => $productId,
          'price'        => (float) $product->get_price(),
          'in_stock'     => $product->is_in_stock(),
          'category_ids' => $product->get_category_ids(),
      ]);
  }

  public function registerSearchRoute(): void
  {
      register_rest_route('agentic-lab/v1', '/products/semantic-search', [
          'methods'             => 'GET',
          'callback'            => [$this, 'handleSearchApi'],
          'permission_callback' => '__return_true', // Публичный каталог
          'args'                => [
              'q' => [
                  'required'          => true,
                  'type'              => 'string',
                  'sanitize_callback' => 'sanitize_text_field',
              ],
              'limit' => [
                  'required' => false,
                  'type'     => 'integer',
                  'default'  => 12,
              ],
          ],
      ]);
  }

  public function handleSearchApi(WP_REST_Request $request): WP_REST_Response|WP_Error
  {
      $query = (string) $request->get_param('q');
      $limit = (int) $request->get_param('limit');

      if (mb_strlen($query) < 2) {
          return new WP_REST_Response(['products' => [], 'total' => 0], 200);
      }

      // 1. Проверка семантического кэша в транзиентах
      $cacheKey = 'agentic_vsearch_' . md5($query . '_' . $limit);
      $cached = get_transient($cacheKey);
      if ($cached !== false && is_array($cached)) {
          return new WP_REST_Response($cached, 200);
      }

      // 2. Векторизация поискового запроса пользователя
      $queryVector = $this->generateEmbedding($query);
      if ($queryVector === null) {
          return new WP_Error('ai_vector_failed', __('Сбой векторизации запроса.', 'agentic-lab'), ['status' => 500]);
      }

      // 3. Выполнение поиска ближайших соседей (ANN) в векторной БД
      $productIds = $this->searchNearestProducts($queryVector, $limit);

      if (empty($productIds)) {
          return new WP_REST_Response(['products' => [], 'total' => 0], 200);
      }

      // 4. Гидратация объектов WooCommerce из объектного кэша Redis
      $products = wc_get_products([
          'include' => $productIds,
          'orderby' => 'include',
          'status'  => 'publish',
      ]);

      $formatted = array_map(static function (WC_Product $p): array {
          return [
              'id'        => $p->get_id(),
              'name'      => $p->get_name(),
              'price'     => $p->get_price(),
              'permalink' => $p->get_permalink(),
              'image'     => wp_get_attachment_image_url($p->get_image_id(), 'woocommerce_thumbnail'),
          ];
      }, $products);

      $responsePayload = [
          'products' => $formatted,
          'total'    => count($formatted),
          'query'    => $query,
      ];

      // Кэшируем результат поиска на 1 час
      set_transient($cacheKey, $responsePayload, HOUR_IN_SECONDS);

      return new WP_REST_Response($responsePayload, 200);
  }

  private function buildProductContext(WC_Product $product): string
  {
      $categories = wp_get_post_terms($product->get_id(), 'product_cat', ['fields' => 'names']);
      $categoryNames = is_array($categories) ? implode(', ', $categories) : '';

      return sprintf(
          'Товар: %s. Категория: %s. Описание: %s. Атрибуты: %s.',
          $product->get_name(),
          $categoryNames,
          wp_strip_all_tags($product->get_short_description() ?: $product->get_description()),
          $product->get_attribute('material') ?: ''
      );
  }

  /**
   * @return list<float>|null
   */
  private function generateEmbedding(string $text): ?array
  {
      $response = wp_remote_post('https://api.openai.com/v1/embeddings', [
          'timeout' => 15,
          'headers' => [
              'Authorization' => 'Bearer ' . $this->openAiKey,
              'Content-Type'  => 'application/json',
          ],
          'body' => wp_json_encode([
              'model' => 'text-embedding-3-small',
              'input' => mb_substr($text, 0, 4000),
          ]),
      ]);

      if (is_wp_error($response) || wp_remote_retrieve_response_code($response) !== 200) {
          return null;
      }

      $body = json_decode(wp_remote_retrieve_body($response), true);
      return $body['data'][0]['embedding'] ?? null;
  }

  /**
   * @param list<float> $vector
   * @param array<string, mixed> $payload
   */
  private function upsertVectorToDb(int $productId, array $vector, array $payload): void
  {
      wp_remote_post("{$this->vectorDbHost}/collections/" . self::COLLECTION_NAME . "/points", [
          'timeout' => 10,
          'headers' => ['Content-Type' => 'application/json'],
          'body'    => wp_json_encode([
              'points' => [
                  [
                      'id'      => $productId,
                      'vector'  => $vector,
                      'payload' => $payload,
                  ],
              ],
          ]),
      ]);
  }

  private function deleteVectorFromDb(int $productId): void
  {
      wp_remote_post("{$this->vectorDbHost}/collections/" . self::COLLECTION_NAME . "/points/delete", [
          'timeout' => 5,
          'headers' => ['Content-Type' => 'application/json'],
          'body'    => wp_json_encode(['points' => [$productId]]),
      ]);
  }

  /**
   * @param list<float> $vector
   * @return list<int>
   */
  private function searchNearestProducts(array $vector, int $limit): array
  {
      $response = wp_remote_post("{$this->vectorDbHost}/collections/" . self::COLLECTION_NAME . "/points/search", [
          'timeout' => 10,
          'headers' => ['Content-Type' => 'application/json'],
          'body'    => wp_json_encode([
              'vector' => $vector,
              'limit'  => $limit,
              'filter' => [
                  'must' => [
                      ['key' => 'in_stock', 'match' => ['value' => true]],
                  ],
              ],
          ]),
      ]);

      if (is_wp_error($response) || wp_remote_retrieve_response_code($response) !== 200) {
          return [];
      }

      $body = json_decode(wp_remote_retrieve_body($response), true);
      $results = $body['result'] ?? [];

      return array_map(static fn(array $item): int => (int) $item['id'], $results);
  }
}