<?php

namespace Aikanen\Modules\CategoryImport;

defined('ABSPATH') || exit;

use Aikanen\ApiClient;
use Aikanen\Modules\BaseModule;
use Aikanen\Modules\CategoryImport\CategoryImportMapper;
use Aikanen\Modules\ProductImport\ProductImportMapper;
use Aikanen\Modules\UsesWebhooks;
use Aikanen\SyncState;

class CategoryImportModule extends BaseModule
{
   use UsesWebhooks;

   public function __construct(
      private ApiClient $api,
      private CategoryImportMapper $categoryMapper,
      private ProductImportMapper $productMapper,
   ) {}

   protected function key(): string
   {
      return 'category_import';
   }

   public function getName(): string
   {
      return __('Category import', 'aikanen');
   }

   public function getDescription(): string
   {
      return __('Import categories from Aikanen to WooCommerce', 'aikanen');
   }

   public function boot(): void
   {
      // Order service group update webhook from Aikanen when auto import is selected (or cancel order on disable) (added to boot to be able to enable on first save with category import module)
      $this->syncWebhooksOnOptionChange('aikanen_auto_import_category', [
         'service_group.created',
         'service_group.updated',
         'service_group.services_attached',
         'service_group.services_detached',
      ]);
   }   

   public function register(): void
   {
      add_action('admin_post_aikanen_fetch_groups', [$this, 'handleFetchGroups']);
      add_action('admin_post_aikanen_save_category_mapping', [$this, 'handleSaveCategoryMapping']);
      add_action('admin_post_aikanen_unlink_category', [$this, 'handleUnlinkCategory']);
      add_action('admin_post_aikanen_cancel_category_mapping', [$this, 'handleCancelCategoryMapping']);

      add_filter('manage_product_cat_columns', [$this, 'addSyncColumn']);
      add_action('product_cat_edit_form_fields', [$this, 'renderSyncFields']); 

      add_action('rest_api_init', [$this, 'registerWebhookEndpoint']); // Register endpoint for receiving webhooks
   }

   public function registerWebhookEndpoint(): void
   {
      register_rest_route('aikanen/v1', 'webhook/' . $this->key(), [
         'methods' => 'POST',
         'callback' => [$this, 'handleWebhook'],
         'permission_callback' => [$this, 'verifyWebhookSignature'],
      ]);
   }

   public function handleWebhook(\WP_REST_Request $request): \WP_REST_Response
   {
      if (!get_option('aikanen_auto_import_category')) {
         return new \WP_REST_Response(['ok' => true]);
      }

      $payload = $request->get_json_params();
      $event = $payload['event'] ?? '';
      $data = $payload['data'] ?? [];

      SyncState::$suppressOutbound = true;
      try {
         if ($event === 'service_group.created' || $event === 'service_group.updated') {
            $this->handleGroupUpserted($data);
         } elseif ($event === 'service_group.services_attached') {
            $this->handleServicesAttached($data);
         } elseif ($event === 'service_group.services_detached') {
            $this->handleServicesDetached($data);
         }
      } finally {
         SyncState::$suppressOutbound = false; // Always release lock after processing
      }

      return new \WP_REST_Response(['ok' => true]);
   }

   // Save category (Aikanen service group)
   public function handleGroupUpserted(array $data): void
   {
      $group = $data['service_group'] ?? null;
      if (!$group) return;

      $this->categoryMapper->upsert($group);
   }  

   // Attach product to category
   public function handleServicesAttached(array $data): void
   {
      $groupId = $data['service_group_id'] ?? null;
      $serviceIds = $data['service_ids'] ?? [];

      if (!$groupId || empty($serviceIds)) return;

      $termId = $this->categoryMapper->findCategoryByAikanenId($groupId);

      if (!$termId) return; // Group not mapped - nothing to do

      foreach ($serviceIds as $serviceId) {
         $productId = $this->productMapper->findProductByAikanenId($serviceId);

         if ($productId) {
            wp_set_object_terms($productId, $termId, 'product_cat', true); // append, don't replace
         }
      }
   }

   // Detach product from category
   public function handleServicesDetached(array $data): void
   {
      $groupId = $data['service_group_id'] ?? null;
      $serviceIds = $data['service_ids'] ?? [];

      if (!$groupId || empty($serviceIds)) return;

      $termId = $this->categoryMapper->findCategoryByAikanenId($groupId);

      if (!$termId) return;

      foreach ($serviceIds as $serviceId) {
         $productId = $this->productMapper->findProductByAikanenId($serviceId);

         if ($productId) {
            wp_remove_object_terms($productId, $termId, 'product_cat');
         }
      }
   }

   // Get service groups from Aikanen
   public function handleFetchGroups(): void
   {
      check_admin_referer('aikanen_fetch_groups');

      if (!current_user_can('manage_woocommerce')) {
         wp_die('Unauthorized.');
      }

      $response = $this->api->get('/service_groups');

      $groups = array_map(function ($item) {
         return array_merge(['id' => $item['id']], $item['attributes'] ?? []);
      }, $response['data'] ?? []);

      set_transient('aikanen_fetched_groups', $groups, 10 * MINUTE_IN_SECONDS);

      wp_safe_redirect(admin_url('admin.php?page=aikanen-categories&aikanen_mapping=1'));
      exit;
   }

   // Save category mapping to match categories to selected Aikanen service groups
   public function handleSaveCategoryMapping(): void
   {
      check_admin_referer('aikanen_save_category_mapping');

      if (!current_user_can('manage_woocommerce')) {
         wp_die('Unauthorized.');
      }

      $raw = array_map('sanitize_text_field', (array) wp_unslash($_POST['category_map'] ?? []));
      $map = [];
      foreach ($raw as $k => $v) {
         $map[sanitize_text_field($k)] = $v;
      }

      foreach ($map as $groupId => $termIdOrAction) {
         $groupId = sanitize_text_field($groupId);

         if ($termIdOrAction === '__create__') {
            $groups = get_transient('aikanen_fetched_groups') ?: [];
            $group = current(array_filter($groups, fn($g) => $g['id'] === $groupId));

            if (!$group) continue;

            $this->categoryMapper->upsert($group);
            continue;
         }

         $termId = (int) $termIdOrAction;

         if (!$termId) continue;

         $existing = get_term_meta($termId, CategoryImportMapper::META_AIKANEN_ID, true);

         if ($existing && $existing !== $groupId) continue;

         update_term_meta($termId, CategoryImportMapper::META_AIKANEN_ID, $groupId);
      }

      delete_transient('aikanen_fetched_groups');

      wp_safe_redirect(admin_url('admin.php?page=aikanen-categories&aikanen_mapping_saved=1'));
      exit;
   }

   // Cancel mapping on preview
   public function handleCancelCategoryMapping(): void
   {
      if (
         !current_user_can('manage_woocommerce') ||
         !check_admin_referer('aikanen_cancel_category_mapping')
      ) {
         wp_die('Unauthorized.');
      }

      delete_transient('aikanen_fetched_groups');
      wp_safe_redirect(admin_url('admin.php?page=aikanen-categories'));
      exit;
   }   

   // Remove Aikanen linking (aikanen meta ID) from category
   public function handleUnlinkCategory(): void
   {
      $termId = absint(wp_unslash($_POST['term_id'] ?? 0));
      if (
         !$termId ||
         !current_user_can('manage_woocommerce') ||
         !check_admin_referer('aikanen_unlink_category_' . $termId)
      ) {
         wp_die('Unauthorized.');
      }

      delete_term_meta($termId, CategoryImportMapper::META_AIKANEN_ID);

      wp_safe_redirect(admin_url('admin.php?page=aikanen-categories'));
      exit;
   }

   // Add sync details to category edit page
   public function addSyncColumn(array $columns): array
   {
      $columns['aikanen_sync'] = __('Aikanen', 'aikanen');
      return $columns;
   }

   public function renderSyncFields(\WP_Term $term): void
   {
      $groupId = get_term_meta($term->term_id, CategoryImportMapper::META_AIKANEN_ID, true);
      ?>
      <tr class="form-field">
         <th scope="row"><?php esc_html_e('Aikanen service group ID', 'aikanen'); ?></th>
         <td>
            <?php if ($groupId): ?>
               <?php echo esc_html($groupId); ?>
            <?php else: ?>
               <p class="description"><?php esc_html_e('Not linked to an Aikanen group.', 'aikanen'); ?></p>
            <?php endif; ?>
         </td>
      </tr>
      <?php
   }   
}