Started refactoring of view service

Phasing out the view service from being a generic 'service' class,
moving the core create/delete methods into the model.
The idea is that the existing query work will need to interlink
with the favourite system so maybe we have a (or many composable)
query building classes rather than mixing query building and
create/delete work as per the old service.

app/Actions/View.php

@@ -1,8 +1,19 @@
 <?php namespace BookStack\Actions;
 
+use BookStack\Interfaces\Viewable;
 use BookStack\Model;
 use Illuminate\Database\Eloquent\Relations\MorphTo;
 
+/**
+ * Class View
+ * Views are stored per-item per-person within the database.
+ * They can be used to find popular items or recently viewed items
+ * at a per-person level. They do not record every view instance as an
+ * activity. Only the latest and original view times could be recognised.
+ *
+ * @property int $views
+ * @property int $user_id
+ */
 class View extends Model
 {
 
@@ -15,4 +26,32 @@ class View extends Model
     {
         return $this->morphTo();
     }
+
+    /**
+     * Increment the current user's view count for the given viewable model.
+     */
+    public static function incrementFor(Viewable $viewable): int
+    {
+        $user = user();
+        if (is_null($user) || $user->isDefault()) {
+            return 0;
+        }
+
+        /** @var View $view */
+        $view = $viewable->views()->firstOrNew([
+            'user_id' => $user->id,
+        ], ['views' => 0]);
+
+        $view->save(['views' => $view->views + 1]);
+
+        return $view->views;
+    }
+
+    /**
+     * Clear all views from the system.
+     */
+    public static function clearAll()
+    {
+        static::query()->truncate();
+    }
 }