From faf9c3796cebaddcf81198b215b89b6eee445162 Mon Sep 17 00:00:00 2001
From: Alexander Zinchuk <alx.zinchuk@gmail.com>
Date: Sat, 5 Mar 2022 18:06:28 +0100
Subject: [PATCH] Management: Avoid infinite requests after adding chat member

---
 src/modules/actions/api/chats.ts | 16 ++--------------
 src/modules/reducers/chats.ts    | 26 ++++++++++++++++++++++++--
 2 files changed, 26 insertions(+), 16 deletions(-)

diff --git a/src/modules/actions/api/chats.ts b/src/modules/actions/api/chats.ts
index 392dd28a0..c30df2c80 100644
--- a/src/modules/actions/api/chats.ts
+++ b/src/modules/actions/api/chats.ts
@@ -23,7 +23,7 @@ import {
   addChats, addUsers, addUserStatuses, replaceThreadParam,
   updateChatListIds, updateChats, updateChat, updateChatListSecondaryInfo,
   updateManagementProgress, leaveChat, replaceUsers, replaceUserStatuses,
-  replaceChats, replaceChatListIds,
+  replaceChats, replaceChatListIds, addChatMembers,
 } from '../../reducers';
 import {
   selectChat, selectUser, selectChatListType, selectIsChatPinned,
@@ -953,19 +953,7 @@ addReducer('loadMoreMembers', (global) => {
 
     global = getGlobal();
     global = addUsers(global, buildCollectionByKey(users, 'id'));
-
-    const newMemberIds = new Set(members.map(m => m.userId));
-    const preservedMembers = chat.fullInfo?.members?.filter((m) => !newMemberIds.has(m.userId)) || [];
-
-    global = updateChat(global, chat.id, {
-      fullInfo: {
-        ...chat.fullInfo,
-        members: [
-          ...preservedMembers,
-          ...members,
-        ],
-      },
-    });
+    global = addChatMembers(global, chat, members);
     setGlobal(global);
   })();
 });
diff --git a/src/modules/reducers/chats.ts b/src/modules/reducers/chats.ts
index 5ad0de83a..ed6ca4690 100644
--- a/src/modules/reducers/chats.ts
+++ b/src/modules/reducers/chats.ts
@@ -1,8 +1,8 @@
 import { GlobalState } from '../../global/types';
-import { ApiChat, ApiPhoto } from '../../api/types';
+import { ApiChat, ApiChatMember, ApiPhoto } from '../../api/types';
 
 import { ARCHIVED_FOLDER_ID } from '../../config';
-import { omit } from '../../util/iteratees';
+import { areSortedArraysEqual, omit } from '../../util/iteratees';
 import { selectChatListType } from '../selectors';
 
 export function replaceChatListIds(
@@ -216,3 +216,25 @@ export function leaveChat(global: GlobalState, leftChatId: string): GlobalState
 
   return global;
 }
+
+export function addChatMembers(global: GlobalState, chat: ApiChat, membersToAdd: ApiChatMember[]): GlobalState {
+  const currentMembers = chat.fullInfo?.members;
+  const newMemberIds = new Set(membersToAdd.map(m => m.userId));
+  const updatedMembers = [
+    ...currentMembers?.filter((m) => !newMemberIds.has(m.userId)) || [],
+    ...membersToAdd,
+  ];
+  const currentIds = currentMembers?.map(({ userId }) => userId) || [];
+  const updatedIds = updatedMembers.map(({ userId }) => userId);
+
+  if (areSortedArraysEqual(currentIds, updatedIds)) {
+    return global;
+  }
+
+  return updateChat(global, chat.id, {
+    fullInfo: {
+      ...chat.fullInfo,
+      members: updatedMembers,
+    },
+  });
+}