Add priority column to favorites

When inserting a new favorite, the new favorite gets the priority + 1 of
the favorite with the currently highest priority. If no favorite is
stored for the kind the new favorite gets the priority 0.

When deleting a favorite, all favorites with higher priority are
decremented by 1.

application/controllers/FavoriteController.php

@@ -9,7 +9,10 @@
 use Icinga\Module\Kubernetes\Common\Database;
 use Icinga\Module\Kubernetes\Forms\FavorForm;
 use Icinga\Module\Kubernetes\Forms\UnfavorForm;
+use Icinga\Module\Kubernetes\Model\Favorite;
 use Icinga\Module\Kubernetes\Web\Controller;
+use ipl\Sql\Expression;
+use ipl\Stdlib\Filter;
 use Throwable;
 
 class FavoriteController extends Controller
@@ -29,12 +32,24 @@ public function favorAction(): void
                 $username = Auth::getInstance()->getUser()->getUsername();
 
                 try {
+                    $highestPriorityFavorite = Favorite::on($db)
+                        ->columns('priority')
+                        ->filter(
+                            Filter::all(
+                                Filter::equal('kind', $kind),
+                                Filter::equal('username', $username)
+                            )
+                        )
+                        ->orderBy('priority', SORT_DESC)
+                        ->first();
+
                     $db->insert(
                         'favorite',
                         [
                             'resource_uuid' => $uuid,
                             'kind'          => $kind,
                             'username'      => $username,
+                            'priority'      => ($highestPriorityFavorite?->priority ?? -1) + 1,
                         ]
                     );
                 } catch (Throwable $e) {
@@ -62,13 +77,49 @@ public function unfavorAction(): void
                 $uuid = $this->params->get('uuid');
                 $username = Auth::getInstance()->getUser()->getUsername();
                 try {
+                    $transactionStarted = false;
+                    if (! $db->inTransaction()) {
+                        $transactionStarted = true;
+                        $db->beginTransaction();
+                    }
+
+                    $favoriteToDelete = Favorite::on($db)
+                        ->filter(Filter::all(
+                            Filter::equal('resource_uuid', $uuid),
+                            Filter::equal('username', $username)
+                        ))
+                        ->first();
+
                     $db->delete(
                         'favorite',
                         [
                             'resource_uuid = ?' => $uuid,
                             'username = ?'      => $username,
                         ]
                     );
+
+                    $affectedFavorites = Favorite::on($db)
+                        ->columns(['resource_uuid', 'username'])
+                        ->filter(
+                            Filter::all(
+                                Filter::equal('kind', $favoriteToDelete->kind),
+                                Filter::equal('username', $username),
+                                Filter::greaterThan('priority', $favoriteToDelete->priority)
+                            )
+                        )
+                        ->orderBy('priority', SORT_ASC);
+
+                    foreach ($affectedFavorites as $favorite) {
+                        $db->update(
+                            'favorite',
+                            ['priority' => new Expression('priority - 1')],
+                            ['resource_uuid = ?' => $favorite->resource_uuid, 'username = ?' => $favorite->username]
+                        );
+                    }
+
+                    if ($transactionStarted) {
+                        $db->commitTransaction();
+                    }
                 } catch (Throwable $e) {
                     Logger::error($e);
                     Logger::error($e->getTraceAsString());

library/Kubernetes/Model/Favorite.php

@@ -56,6 +56,7 @@ public function getColumnDefinitions(): array
             'resource_uuid' => $this->translate('Resource UUID'),
             'kind'          => $this->translate('Resource Kind'),
             'username'      => $this->translate('Username'),
+            'priority'      => $this->translate('Priority'),
         ];
     }
 
@@ -65,6 +66,7 @@ public function getColumns(): array
             'resource_uuid',
             'kind',
             'username',
+            'priority',
         ];
     }