+ /**
+ * Save a page update draft.
+ * @param Page $page
+ * @param array $data
+ * @return PageRevision
+ */
+ public function saveUpdateDraft(Page $page, $data = [])
+ {
+ $userId = user()->id;
+ $drafts = $this->userUpdateDraftsQuery($page, $userId)->get();
+
+ if ($drafts->count() > 0) {
+ $draft = $drafts->first();
+ } else {
+ $draft = $this->pageRevision->newInstance();
+ $draft->page_id = $page->id;
+ $draft->slug = $page->slug;
+ $draft->book_slug = $page->book->slug;
+ $draft->created_by = $userId;
+ $draft->type = 'update_draft';
+ }
+
+ $draft->fill($data);
+ if (setting('app-editor') !== 'markdown') $draft->markdown = '';
+
+ $draft->save();
+ return $draft;
+ }
+
+ /**
+ * Update a draft page.
+ * @param Page $page
+ * @param array $data
+ * @return Page
+ */
+ public function updateDraftPage(Page $page, $data = [])
+ {
+ $page->fill($data);
+
+ if (isset($data['html'])) {
+ $page->text = strip_tags($data['html']);
+ }
+
+ $page->save();
+ return $page;
+ }
+
+ /**
+ * The base query for getting user update drafts.
+ * @param Page $page
+ * @param $userId
+ * @return mixed
+ */
+ private function userUpdateDraftsQuery(Page $page, $userId)
+ {
+ return $this->pageRevision->where('created_by', '=', $userId)
+ ->where('type', 'update_draft')
+ ->where('page_id', '=', $page->id)
+ ->orderBy('created_at', 'desc');
+ }
+
+ /**
+ * Checks whether a user has a draft version of a particular page or not.
+ * @param Page $page
+ * @param $userId
+ * @return bool
+ */
+ public function hasUserGotPageDraft(Page $page, $userId)
+ {
+ return $this->userUpdateDraftsQuery($page, $userId)->count() > 0;
+ }
+
+ /**
+ * Get the latest updated draft revision for a particular page and user.
+ * @param Page $page
+ * @param $userId
+ * @return mixed
+ */
+ public function getUserPageDraft(Page $page, $userId)
+ {
+ return $this->userUpdateDraftsQuery($page, $userId)->first();
+ }
+
+ /**
+ * Get the notification message that informs the user that they are editing a draft page.
+ * @param PageRevision $draft
+ * @return string
+ */
+ public function getUserPageDraftMessage(PageRevision $draft)
+ {
+ $message = 'You are currently editing a draft that was last saved ' . $draft->updated_at->diffForHumans() . '.';
+ if ($draft->page->updated_at->timestamp > $draft->updated_at->timestamp) {
+ $message .= "\n This page has been updated by since that time. It is recommended that you discard this draft.";
+ }
+ return $message;
+ }
+
+ /**
+ * Check if a page is being actively editing.
+ * Checks for edits since last page updated.
+ * Passing in a minuted range will check for edits
+ * within the last x minutes.
+ * @param Page $page
+ * @param null $minRange
+ * @return bool
+ */
+ public function isPageEditingActive(Page $page, $minRange = null)
+ {
+ $draftSearch = $this->activePageEditingQuery($page, $minRange);
+ return $draftSearch->count() > 0;
+ }
+
+ /**
+ * Get a notification message concerning the editing activity on
+ * a particular page.
+ * @param Page $page
+ * @param null $minRange
+ * @return string
+ */
+ public function getPageEditingActiveMessage(Page $page, $minRange = null)
+ {
+ $pageDraftEdits = $this->activePageEditingQuery($page, $minRange)->get();
+ $userMessage = $pageDraftEdits->count() > 1 ? $pageDraftEdits->count() . ' users have' : $pageDraftEdits->first()->createdBy->name . ' has';
+ $timeMessage = $minRange === null ? 'since the page was last updated' : 'in the last ' . $minRange . ' minutes';
+ $message = '%s started editing this page %s. Take care not to overwrite each other\'s updates!';
+ return sprintf($message, $userMessage, $timeMessage);
+ }
+
+ /**
+ * A query to check for active update drafts on a particular page.
+ * @param Page $page
+ * @param null $minRange
+ * @return mixed
+ */
+ private function activePageEditingQuery(Page $page, $minRange = null)
+ {
+ $query = $this->pageRevision->where('type', '=', 'update_draft')
+ ->where('page_id', '=', $page->id)
+ ->where('updated_at', '>', $page->updated_at)
+ ->where('created_by', '!=', user()->id)
+ ->with('createdBy');
+
+ if ($minRange !== null) {
+ $query = $query->where('updated_at', '>=', Carbon::now()->subMinutes($minRange));
+ }
+
+ return $query;
+ }
+