feat: index and sync view_count for fof/discussion-views sort support

- Rename SavingJob to UpdateSearchJob
- Add ViewsSearchJob for lightweight partial view_count updates
- Add probabilistic sync throttle in DiscussionSeeder::viewingOn()
  to avoid an ES update on every page view
- Add view_count to mapping, DiscussionSeeder::toDocument(), and
  translateSort
- Log a warning and skip instead of 500ing on unknown sort fields

src/Api/Controllers/SearchController.php

@@ -48,6 +48,7 @@ class SearchController extends ListDiscussionsController
         'lastPostedAt' => 'updated_at',
         'createdAt'    => 'created_at',
         'commentCount' => 'comment_count',
+        'view_count'   => 'view_count',
     ];
 
     protected Collection $searchers;
@@ -107,9 +108,19 @@ class SearchController extends ListDiscussionsController
                 $this->addFilters($filterQuery, $actor, $filters)
             );
 
+        $knownSortFields = array_merge(array_values($this->translateSort), ['rawId']);
+
         foreach ($this->extractSort($request) as $field => $direction) {
-            $field = $this->translateSort[$field] ?? $field;
-            $builder->addSort(new Sort($field, $direction));
+            $translated = $this->translateSort[$field] ?? $field;
+
+            if (!in_array($translated, $knownSortFields)) {
+                resolve(\Psr\Log\LoggerInterface::class)->warning(
+                    "blomstra/search: unknown sort field \"{$field}\", ignoring."
+                );
+                continue;
+            }
+
+            $builder->addSort(new Sort($translated, $direction));
         }
 
         $response = $builder->search();

src/Commands/BuildCommand.php

@@ -13,7 +13,7 @@
 namespace Blomstra\Search\Commands;
 
 use Blomstra\Search\Jobs\Job;
-use Blomstra\Search\Jobs\SavingJob;
+use Blomstra\Search\Jobs\UpdateSearchJob;
 use Blomstra\Search\Seeders\Seeder;
 use Elasticsearch\Client;
 use Flarum\Settings\SettingsRepositoryInterface;
@@ -71,6 +71,7 @@ class BuildCommand extends Command
                 'recipient_groups' => ['type' => 'integer'],
                 'recipient_users'  => ['type' => 'integer'],
                 'comment_count'    => ['type' => 'integer'],
+                'view_count'       => ['type' => 'integer'],
             ],
         ];
 
@@ -181,7 +182,7 @@ class BuildCommand extends Command
                 }
 
                 if ($collection->isNotEmpty()) {
-                    $queue->pushOn(Job::$onQueue, new SavingJob($collection, $seeder));
+                    $queue->pushOn(Job::$onQueue, new UpdateSearchJob($collection, $seeder));
                 }
 
                 $this->info("IDs {$rangeFrom}–{$rangeTo} | type: {$seeder->type()} | queued: {$collection->count()}.");

src/Jobs/UpdateSearchJob.php

@@ -17,7 +17,7 @@ use Elasticsearch\Client;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Support\Arr;
 
-class SavingJob extends Job
+class UpdateSearchJob extends Job
 {
     public function handle(Client $client)
     {

src/Jobs/ViewsSearchJob.php

@@ -0,0 +1,53 @@
+<?php
+
+/*
+ * This file is part of blomstra/search.
+ *
+ * Copyright (c) 2022 Blomstra Ltd.
+ *
+ * For the full copyright and license information, please view the LICENSE.md
+ * file that was distributed with this source code.
+ *
+ */
+
+namespace Blomstra\Search\Jobs;
+
+use Elasticsearch\Client;
+use Flarum\Api\Serializer\DiscussionSerializer;
+use Flarum\Discussion\Discussion;
+use Flarum\Queue\AbstractJob;
+
+class ViewsSearchJob extends AbstractJob
+{
+    protected string $index;
+
+    public function __construct(protected int $discussionId)
+    {
+        $this->index = resolve('blomstra.search.elastic_index');
+
+        if (Job::$onQueue) {
+            $this->onQueue(Job::$onQueue);
+        }
+    }
+
+    public function handle(Client $client): void
+    {
+        $discussion = Discussion::find($this->discussionId);
+
+        if (!$discussion) {
+            return;
+        }
+
+        $type = resolve(DiscussionSerializer::class)->getType(new Discussion());
+
+        $client->update([
+            'index'             => $this->index,
+            'id'                => "$type:{$this->discussionId}",
+            'retry_on_conflict' => 3,
+            'ignore'            => [404],
+            'body'              => [
+                'doc' => ['view_count' => (int) $discussion->view_count],
+            ],
+        ]);
+    }
+}

src/Provider.php

@@ -14,7 +14,8 @@ namespace Blomstra\Search;
 
 use Blomstra\Search\Jobs\DeletingJob;
 use Blomstra\Search\Jobs\Job;
-use Blomstra\Search\Jobs\SavingJob;
+use Blomstra\Search\Jobs\UpdateSearchJob;
+use Blomstra\Search\Jobs\ViewsSearchJob;
 use Elasticsearch\Client as Elastic;
 use Elasticsearch\ClientBuilder;
 use Flarum\Api\Client;
@@ -108,12 +109,18 @@ class Provider extends AbstractServiceProvider
         /** @var string|Seeders\Seeder $seeder */
         foreach ($seeders as $seeder) {
             $seeder::savingOn($events, function ($model) use ($queue, $seeder) {
-                $queue->pushOn(Job::$onQueue, new SavingJob(Collection::make([$model]), $seeder));
+                $queue->pushOn(Job::$onQueue, new UpdateSearchJob(Collection::make([$model]), $seeder));
             });
 
             $seeder::deletingOn($events, function ($model) use ($queue, $seeder) {
                 $queue->pushOn(Job::$onQueue, new DeletingJob(Collection::make([$model]), $seeder));
             });
+
+            if (method_exists($seeder, 'viewingOn')) {
+                $seeder::viewingOn($events, function (int $discussionId) use ($queue) {
+                    $queue->pushOn(Job::$onQueue, new ViewsSearchJob($discussionId));
+                });
+            }
         }
     }
 }

src/Seeders/DiscussionSeeder.php

@@ -16,7 +16,9 @@ use Blomstra\Search\Save\Document;
 use Flarum\Api\Serializer\DiscussionSerializer;
 use Flarum\Discussion\Discussion;
 use Flarum\Discussion\Event as Core;
+use Flarum\Extension\ExtensionManager;
 use FoF\Byobu\Events as Byobu;
+use FoF\DiscussionViews\Events\DiscussionWasViewed;
 use Illuminate\Contracts\Events\Dispatcher;
 use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Model;
@@ -58,6 +60,27 @@ class DiscussionSeeder extends Seeder
         });
     }
 
+    public static function viewingOn(Dispatcher $events, callable $callable): void
+    {
+        if (!resolve(ExtensionManager::class)->isEnabled('fof-discussion-views')) {
+            return;
+        }
+
+        $events->listen(DiscussionWasViewed::class, function (DiscussionWasViewed $event) use ($callable) {
+            $viewCount = $event->discussion->view_count;
+
+            $shouldSync = match (true) {
+                $viewCount < 15  => true,
+                $viewCount < 100 => rand(1, 3) === 1,
+                default          => rand(1, 19) === 1,
+            };
+
+            if ($shouldSync) {
+                $callable($event->discussion->id);
+            }
+        });
+    }
+
     public static function deletingOn(Dispatcher $events, callable $callable)
     {
         $events->listen([
@@ -107,6 +130,10 @@ class DiscussionSeeder extends Seeder
             $document['is_sticky'] = (bool) $model->is_sticky;
         }
 
+        if ($this->extensionEnabled('fof-discussion-views')) {
+            $document['view_count'] = (int) ($model->view_count ?? 0);
+        }
+
         return $document;
     }
 }