Re-structured the app code to be feature based rather than code type based

app/Actions/ActivityService.php

@@ -0,0 +1,174 @@
+<?php namespace BookStack\Actions;
+
+use BookStack\Actions\Activity;
+use BookStack\Auth\Permissions\PermissionService;
+use BookStack\Entities\Entity;
+use Session;
+
+class ActivityService
+{
+    protected $activity;
+    protected $user;
+    protected $permissionService;
+
+    /**
+     * ActivityService constructor.
+     * @param \BookStack\Actions\Activity $activity
+     * @param PermissionService $permissionService
+     */
+    public function __construct(Activity $activity, PermissionService $permissionService)
+    {
+        $this->activity = $activity;
+        $this->permissionService = $permissionService;
+        $this->user = user();
+    }
+
+    /**
+     * Add activity data to database.
+     * @param Entity $entity
+     * @param        $activityKey
+     * @param int $bookId
+     * @param bool $extra
+     */
+    public function add(Entity $entity, $activityKey, $bookId = 0, $extra = false)
+    {
+        $activity = $this->activity->newInstance();
+        $activity->user_id = $this->user->id;
+        $activity->book_id = $bookId;
+        $activity->key = strtolower($activityKey);
+        if ($extra !== false) {
+            $activity->extra = $extra;
+        }
+        $entity->activity()->save($activity);
+        $this->setNotification($activityKey);
+    }
+
+    /**
+     * Adds a activity history with a message & without binding to a entity.
+     * @param            $activityKey
+     * @param int $bookId
+     * @param bool|false $extra
+     */
+    public function addMessage($activityKey, $bookId = 0, $extra = false)
+    {
+        $this->activity->user_id = $this->user->id;
+        $this->activity->book_id = $bookId;
+        $this->activity->key = strtolower($activityKey);
+        if ($extra !== false) {
+            $this->activity->extra = $extra;
+        }
+        $this->activity->save();
+        $this->setNotification($activityKey);
+    }
+
+
+    /**
+     * Removes the entity attachment from each of its activities
+     * and instead uses the 'extra' field with the entities name.
+     * Used when an entity is deleted.
+     * @param Entity $entity
+     * @return mixed
+     */
+    public function removeEntity(Entity $entity)
+    {
+        $activities = $entity->activity;
+        foreach ($activities as $activity) {
+            $activity->extra = $entity->name;
+            $activity->entity_id = 0;
+            $activity->entity_type = null;
+            $activity->save();
+        }
+        return $activities;
+    }
+
+    /**
+     * Gets the latest activity.
+     * @param int $count
+     * @param int $page
+     * @return array
+     */
+    public function latest($count = 20, $page = 0)
+    {
+        $activityList = $this->permissionService
+            ->filterRestrictedEntityRelations($this->activity, 'activities', 'entity_id', 'entity_type')
+            ->orderBy('created_at', 'desc')->with('user', 'entity')->skip($count * $page)->take($count)->get();
+
+        return $this->filterSimilar($activityList);
+    }
+
+    /**
+     * Gets the latest activity for an entity, Filtering out similar
+     * items to prevent a message activity list.
+     * @param Entity $entity
+     * @param int $count
+     * @param int $page
+     * @return array
+     */
+    public function entityActivity($entity, $count = 20, $page = 0)
+    {
+        if ($entity->isA('book')) {
+            $query = $this->activity->where('book_id', '=', $entity->id);
+        } else {
+            $query = $this->activity->where('entity_type', '=', get_class($entity))
+                ->where('entity_id', '=', $entity->id);
+        }
+        
+        $activity = $this->permissionService
+            ->filterRestrictedEntityRelations($query, 'activities', 'entity_id', 'entity_type')
+            ->orderBy('created_at', 'desc')->with(['entity', 'user.avatar'])->skip($count * $page)->take($count)->get();
+
+        return $this->filterSimilar($activity);
+    }
+
+    /**
+     * Get latest activity for a user, Filtering out similar
+     * items.
+     * @param $user
+     * @param int $count
+     * @param int $page
+     * @return array
+     */
+    public function userActivity($user, $count = 20, $page = 0)
+    {
+        $activityList = $this->permissionService
+            ->filterRestrictedEntityRelations($this->activity, 'activities', 'entity_id', 'entity_type')
+            ->orderBy('created_at', 'desc')->where('user_id', '=', $user->id)->skip($count * $page)->take($count)->get();
+        return $this->filterSimilar($activityList);
+    }
+
+    /**
+     * Filters out similar activity.
+     * @param Activity[] $activities
+     * @return array
+     */
+    protected function filterSimilar($activities)
+    {
+        $newActivity = [];
+        $previousItem = false;
+        foreach ($activities as $activityItem) {
+            if ($previousItem === false) {
+                $previousItem = $activityItem;
+                $newActivity[] = $activityItem;
+                continue;
+            }
+            if (!$activityItem->isSimilarTo($previousItem)) {
+                $newActivity[] = $activityItem;
+            }
+            $previousItem = $activityItem;
+        }
+        return $newActivity;
+    }
+
+    /**
+     * Flashes a notification message to the session if an appropriate message is available.
+     * @param $activityKey
+     */
+    protected function setNotification($activityKey)
+    {
+        $notificationTextKey = 'activities.' . $activityKey . '_notification';
+        if (trans()->has($notificationTextKey)) {
+            $message = trans($notificationTextKey);
+            Session::flash('success', $message);
+        }
+    }
+}