<?php

namespace Aikanen\Modules;

defined('ABSPATH') || exit;

trait UsesWebhooks
{
   // Handle registering or deregistering a webhook on feature toggle
   protected function syncWebhooksOnOptionChange(string $option, array $events): void
   {
      $handler = function (string $name, mixed $new, mixed $old = false) use ($option, $events) {
         if ($name !== $option) return;

         if ($new && !$old) {
            foreach ($events as $event) $this->registerWebhook($event);
         } elseif (!$new && $old) {
            foreach ($events as $event) $this->deregisterWebhook($event);
         }
      };

      add_action('added_option', fn ($name, $value) => $handler($name, $value), 10, 2);
      add_action('updated_option', fn ($name, $old, $new) => $handler($name, $new, $old), 10, 3);
   }

   // Order a webhook from Aikanen to get notified on specific event
   private function registerWebhook(string $event): void
   {
      $secret = get_option('aikanen_webhook_secret');
      if (!$secret) return;

      $url = rest_url("aikanen/v1/webhook/{$this->key()}");

      try {
         $response = $this->api->post('/webhooks', [
            'event' => $event,
            'url' => $url,
            'secret' => $secret,
         ]);

         $id = $response['data']['id'] ?? null;
         if ($id) {
            update_option("aikanen_webhook_id_{$this->key()}_{$event}", $id);
         }
      } catch (\Exception $e) {
         set_transient('aikanen_notice', [
            'type' => 'error',
            'message' => sprintf(
               /* translators: %s: error message */
               __('Failed to register webhook: %s', 'aikanen'),
               $e->getMessage()
            ),
         ], 30);
      }
   }

   // Delete a webhook from Aikanen to stop getting notified on specific event
   private function deregisterWebhook(string $event): void
   {
      $id = get_option("aikanen_webhook_id_{$this->key()}_{$event}");
      if (!$id) return;

      try {
         $this->api->delete("/webhooks/{$id}");
         delete_option("aikanen_webhook_id_{$this->key()}_{$event}");
      } catch (\Exception $e) {
         set_transient('aikanen_notice', [
            'type' => 'error',
            'message' => sprintf(
               /* translators: %s: error message */
               __('Failed to deregister webhook: %s', 'aikanen'),
               $e->getMessage()
            ),
         ], 30);
      }
   }

   // Verify signature of received webhook matches expected (calculated from saved secret and webhook data)
   public function verifyWebhookSignature(\WP_REST_Request $request): bool
   {
      $secret = get_option('aikanen_webhook_secret');

      if (!$secret) { // No secret saved to Woo
         return false;
      }

      $signature = $request->get_header('signature');

      if (!$signature) { // No signature in received webhook
         return false;
      }

      return hash_equals(
         hash_hmac('sha256', $request->get_body(), $secret),
         $signature
      );
   }   
}