From f7039809a7ea6d184e0506c3a85c7b5e1cb8325a Mon Sep 17 00:00:00 2001
From: Mikunj <mikunj@live.com.au>
Date: Wed, 11 Sep 2019 10:39:32 +1000
Subject: [PATCH] Stop polling upon deleting group chat. Also don't create
 poller if thread has been deleted.

---
 Signal/src/AppDelegate.m                      | 48 +++++++++++++++++--
 .../HomeView/HomeViewController.m             |  9 +++-
 .../Loki/Utilities/Notification+Loki.swift    |  2 +
 3 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/Signal/src/AppDelegate.m b/Signal/src/AppDelegate.m
index 7d9f48d46..7bf576d2e 100644
--- a/Signal/src/AppDelegate.m
+++ b/Signal/src/AppDelegate.m
@@ -321,6 +321,9 @@ static NSTimeInterval launchStartedAt;
     
     // Loki - Observe messages received notifications
     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleNewMessagesReceived:) name:NSNotification.newMessagesReceived object:nil];
+    
+    // Loki - Observe thread deletion notifications
+    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleThreadDeleted:) name:NSNotification.threadDeleted object:nil];
 
     OWSLogInfo(@"application: didFinishLaunchingWithOptions completed.");
 
@@ -1579,26 +1582,61 @@ static NSTimeInterval launchStartedAt;
 
 - (void)createGroupChatPollersIfNeeded
 {
-    if (self.lokiPublicChatPoller == nil) { self.lokiPublicChatPoller = [[LKGroupChatPoller alloc] initForGroup:self.lokiPublicChat]; }
+    // Make sure thread exists
+    __block TSGroupThread *thread;
+    [OWSPrimaryStorage.dbReadWriteConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
+        thread = [TSGroupThread threadWithGroupId:[self.lokiPublicChat.id dataUsingEncoding:NSUTF8StringEncoding] transaction:transaction];
+    }];
+   
+    if (thread != nil && self.lokiPublicChatPoller == nil) {
+        self.lokiPublicChatPoller = [[LKGroupChatPoller alloc] initForGroup:self.lokiPublicChat];
+    }
 }
 
 - (void)createRSSFeedPollersIfNeeded
 {
-    if (self.lokiNewsFeedPoller == nil) { self.lokiNewsFeedPoller = [[LKRSSFeedPoller alloc] initForFeed:self.lokiNewsFeed]; }
+    // Make sure thread exists
+    __block TSGroupThread *lokiNewsFeedThread;
+    [OWSPrimaryStorage.dbReadWriteConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
+        lokiNewsFeedThread = [TSGroupThread threadWithGroupId:[self.lokiNewsFeed.id dataUsingEncoding:NSUTF8StringEncoding] transaction:transaction];
+    }];
+    if (lokiNewsFeedThread != nil && self.lokiNewsFeedPoller == nil) {
+        self.lokiNewsFeedPoller = [[LKRSSFeedPoller alloc] initForFeed:self.lokiNewsFeed];
+    }
+    
+    // We don't need to check thread for this as it's never deletable
     if (self.lokiMessengerUpdatesFeedPoller == nil) { self.lokiMessengerUpdatesFeedPoller = [[LKRSSFeedPoller alloc] initForFeed:self.lokiMessengerUpdatesFeed]; }
 }
 
 - (void)startGroupChatPollersIfNeeded
 {
     [self createGroupChatPollersIfNeeded];
-    [self.lokiPublicChatPoller startIfNeeded];
+    if (self.lokiPublicChatPoller != nil) { [self.lokiPublicChatPoller startIfNeeded]; }
 }
 
 - (void)startRSSFeedPollersIfNeeded
 {
     [self createRSSFeedPollersIfNeeded];
-    [self.lokiNewsFeedPoller startIfNeeded];
-    [self.lokiMessengerUpdatesFeedPoller startIfNeeded];
+    if (self.lokiNewsFeedPoller != nil) { [self.lokiNewsFeedPoller startIfNeeded]; }
+    if (self.lokiMessengerUpdatesFeedPoller != nil) { [self.lokiMessengerUpdatesFeedPoller startIfNeeded]; }
+}
+
+- (void)handleThreadDeleted:(NSNotification *)notification {
+    NSDictionary *userInfo = notification.userInfo;
+    NSString *threadId = (NSString *)userInfo[@"threadId"];
+    if (threadId == nil) { return; }
+    
+    // Check if public chat was deleted
+    if ([threadId isEqualToString:[TSGroupThread threadIdFromGroupId:[self.lokiPublicChat.id dataUsingEncoding:NSUTF8StringEncoding]]] && self.lokiPublicChatPoller != nil) {
+        [self.lokiPublicChatPoller stop];
+        self.lokiPublicChatPoller = nil;
+    }
+    
+    // Check if news feed was deleted
+    if ([threadId isEqualToString:[TSGroupThread threadIdFromGroupId:[self.lokiNewsFeed.id dataUsingEncoding:NSUTF8StringEncoding]]] && self.lokiNewsFeedPoller != nil) {
+        [self.lokiNewsFeedPoller stop];
+        self.lokiNewsFeedPoller = nil;
+    }
 }
 
 @end
diff --git a/Signal/src/ViewControllers/HomeView/HomeViewController.m b/Signal/src/ViewControllers/HomeView/HomeViewController.m
index d92171b60..4a3162af9 100644
--- a/Signal/src/ViewControllers/HomeView/HomeViewController.m
+++ b/Signal/src/ViewControllers/HomeView/HomeViewController.m
@@ -1413,6 +1413,8 @@ typedef NS_ENUM(NSInteger, HomeViewControllerSection) {
 - (void)deleteThread:(TSThread *)thread
 {
     [self.editingDbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
+        /* Loki: Orignal Code
+         =====================
         if ([thread isKindOfClass:[TSGroupThread class]]) {
             TSGroupThread *groupThread = (TSGroupThread *)thread;
             if (groupThread.isLocalUserInGroup) {
@@ -1420,10 +1422,15 @@ typedef NS_ENUM(NSInteger, HomeViewControllerSection) {
                 return;
             }
         }
+        */
 
+        // Loki: For now hard delete all groups
         [thread removeWithTransaction:transaction];
     }];
-
+    
+    // Loki - Post notification
+    [[NSNotificationCenter defaultCenter] postNotificationName:NSNotification.threadDeleted object:nil userInfo:@{ @"threadId": thread.uniqueId }];
+    
     [self updateViewState];
 }
 
diff --git a/SignalServiceKit/src/Loki/Utilities/Notification+Loki.swift b/SignalServiceKit/src/Loki/Utilities/Notification+Loki.swift
index 4969f25b8..25f7bc80a 100644
--- a/SignalServiceKit/src/Loki/Utilities/Notification+Loki.swift
+++ b/SignalServiceKit/src/Loki/Utilities/Notification+Loki.swift
@@ -4,6 +4,7 @@ public extension Notification.Name {
     public static let newMessagesReceived = Notification.Name("newMessagesReceived")
     public static let threadFriendRequestStatusChanged = Notification.Name("threadFriendRequestStatusChanged")
     public static let messageFriendRequestStatusChanged = Notification.Name("messageFriendRequestStatusChanged")
+    public static let threadDeleted = Notification.Name("threadDeleted")
 }
 
 // MARK: - Obj-C
@@ -13,4 +14,5 @@ public extension Notification.Name {
     @objc public static let newMessagesReceived = Notification.Name.newMessagesReceived.rawValue as NSString
     @objc public static let threadFriendRequestStatusChanged = Notification.Name.threadFriendRequestStatusChanged.rawValue as NSString
     @objc public static let messageFriendRequestStatusChanged = Notification.Name.messageFriendRequestStatusChanged.rawValue as NSString
+    @objc public static let threadDeleted = Notification.Name.threadDeleted.rawValue as NSString
 }