From 70991debfd0cf3235bcce4950ca3552af8d9e608 Mon Sep 17 00:00:00 2001
From: Evgeny <evgeny@poberezkin.com>
Date: Tue, 20 Aug 2024 09:29:52 +0100
Subject: [PATCH] ios: optimize performance of updating chats (#4723)

* ios: optimize performance of updating chats

* even simpler

* always use updateChats

* make chats readonly from outside of model
---
 apps/ios/Shared/Model/ChatModel.swift         | 23 +++----------------
 apps/ios/Shared/Model/SimpleXAPI.swift        |  9 +++-----
 apps/ios/Shared/SimpleXApp.swift              |  2 +-
 .../Shared/Views/ChatList/ChatListView.swift  | 10 ++++----
 .../Shared/Views/Database/DatabaseView.swift  |  2 +-
 .../Views/LocalAuth/LocalAuthView.swift       |  3 +--
 apps/ios/SimpleXChat/ChatTypes.swift          |  6 +++++
 7 files changed, 20 insertions(+), 35 deletions(-)

diff --git a/apps/ios/Shared/Model/ChatModel.swift b/apps/ios/Shared/Model/ChatModel.swift
index 4b391b727e..0ac1a9cacb 100644
--- a/apps/ios/Shared/Model/ChatModel.swift
+++ b/apps/ios/Shared/Model/ChatModel.swift
@@ -143,7 +143,7 @@ final class ChatModel: ObservableObject {
     @Published var contentViewAccessAuthenticated: Bool = false
     @Published var laRequest: LocalAuthRequest?
     // list of chat "previews"
-    @Published var chats: [Chat] = []
+    @Published private(set) var chats: [Chat] = []
     @Published var deletedChats: Set<String> = []
     // current chat
     @Published var chatId: String?
@@ -357,25 +357,8 @@ final class ChatModel: ObservableObject {
         }
     }
 
-    func updateChats(with newChats: [ChatData]) {
-        for i in 0..<newChats.count {
-            let c = newChats[i]
-            if let j = getChatIndex(c.id)   {
-                let chat = chats[j]
-                chat.chatInfo = c.chatInfo
-                chat.chatItems = c.chatItems
-                chat.chatStats = c.chatStats
-                if i != j {
-                    if chatId != c.chatInfo.id  {
-                        popChat_(j, to: i)
-                    }  else if i == 0 {
-                        chatToTop = c.chatInfo.id
-                    }
-                }
-            } else {
-                addChat_(Chat(c), at: i)
-            }
-        }
+    func updateChats(_ newChats: [ChatData]) {
+        chats = newChats.map { Chat($0) }
         NtfManager.shared.setNtfBadgeCount(totalUnreadCountForAllUsers())
         popChatCollector.clear()
     }
diff --git a/apps/ios/Shared/Model/SimpleXAPI.swift b/apps/ios/Shared/Model/SimpleXAPI.swift
index 00ac88b071..3abd1e92d1 100644
--- a/apps/ios/Shared/Model/SimpleXAPI.swift
+++ b/apps/ios/Shared/Model/SimpleXAPI.swift
@@ -1591,8 +1591,7 @@ func getUserChatData() throws {
     m.userAddress = try apiGetUserAddress()
     m.chatItemTTL = try getChatItemTTL()
     let chats = try apiGetChats()
-    m.chats = chats.map { Chat.init($0) }
-    m.popChatCollector.clear()
+    m.updateChats(chats)
 }
 
 private func getUserChatDataAsync() async throws {
@@ -1604,14 +1603,12 @@ private func getUserChatDataAsync() async throws {
         await MainActor.run {
             m.userAddress = userAddress
             m.chatItemTTL = chatItemTTL
-            m.chats = chats.map { Chat.init($0) }
-            m.popChatCollector.clear()
+            m.updateChats(chats)
         }
     } else {
         await MainActor.run {
             m.userAddress = nil
-            m.chats = []
-            m.popChatCollector.clear()
+            m.updateChats([])
         }
     }
 }
diff --git a/apps/ios/Shared/SimpleXApp.swift b/apps/ios/Shared/SimpleXApp.swift
index c40f9edf45..621f58dc0c 100644
--- a/apps/ios/Shared/SimpleXApp.swift
+++ b/apps/ios/Shared/SimpleXApp.swift
@@ -133,7 +133,7 @@ struct SimpleXApp: App {
     private func updateChats() {
         do {
             let chats = try apiGetChats()
-            chatModel.updateChats(with: chats)
+            chatModel.updateChats(chats)
             if let id = chatModel.chatId,
                let chat = chatModel.getChat(id) {
                 Task { await loadChat(chat: chat, clearItems: false) }
diff --git a/apps/ios/Shared/Views/ChatList/ChatListView.swift b/apps/ios/Shared/Views/ChatList/ChatListView.swift
index ec49c7b4d1..041b45492d 100644
--- a/apps/ios/Shared/Views/ChatList/ChatListView.swift
+++ b/apps/ios/Shared/Views/ChatList/ChatListView.swift
@@ -501,21 +501,21 @@ func chatStoppedIcon() -> some View {
 struct ChatListView_Previews: PreviewProvider {
     static var previews: some View {
         let chatModel = ChatModel()
-        chatModel.chats = [
-            Chat(
+        chatModel.updateChats([
+            ChatData(
                 chatInfo: ChatInfo.sampleData.direct,
                 chatItems: [ChatItem.getSample(1, .directSnd, .now, "hello")]
             ),
-            Chat(
+            ChatData(
                 chatInfo: ChatInfo.sampleData.group,
                 chatItems: [ChatItem.getSample(1, .directSnd, .now, "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.")]
             ),
-            Chat(
+            ChatData(
                 chatInfo: ChatInfo.sampleData.contactRequest,
                 chatItems: []
             )
 
-        ]
+        ])
         return Group {
             ChatListView(showSettings: Binding.constant(false))
                 .environmentObject(chatModel)
diff --git a/apps/ios/Shared/Views/Database/DatabaseView.swift b/apps/ios/Shared/Views/Database/DatabaseView.swift
index 6b6d3796dc..f5b5287971 100644
--- a/apps/ios/Shared/Views/Database/DatabaseView.swift
+++ b/apps/ios/Shared/Views/Database/DatabaseView.swift
@@ -491,7 +491,7 @@ struct DatabaseView: View {
         appFilesCountAndSize = directoryFileCountAndSize(getAppFilesDirectory())
         do {
             let chats = try apiGetChats()
-            m.updateChats(with: chats)
+            m.updateChats(chats)
         } catch let error {
             logger.error("apiGetChats: cannot update chats \(responseError(error))")
         }
diff --git a/apps/ios/Shared/Views/LocalAuth/LocalAuthView.swift b/apps/ios/Shared/Views/LocalAuth/LocalAuthView.swift
index 5e64f7fb0d..27bb95b599 100644
--- a/apps/ios/Shared/Views/LocalAuth/LocalAuthView.swift
+++ b/apps/ios/Shared/Views/LocalAuth/LocalAuthView.swift
@@ -65,8 +65,7 @@ struct LocalAuthView: View {
                 // Clear sensitive data on screen just in case app fails to hide its views while new database is created
                 m.chatId = nil
                 ItemsModel.shared.reversedChatItems = []
-                m.chats = []
-                m.popChatCollector.clear()
+                m.updateChats([])
                 m.users = []
                 _ = kcAppPassword.set(password)
                 _ = kcSelfDestructPassword.remove()
diff --git a/apps/ios/SimpleXChat/ChatTypes.swift b/apps/ios/SimpleXChat/ChatTypes.swift
index 233f4c19ee..1a9cf4a216 100644
--- a/apps/ios/SimpleXChat/ChatTypes.swift
+++ b/apps/ios/SimpleXChat/ChatTypes.swift
@@ -1500,6 +1500,12 @@ public struct ChatData: Decodable, Identifiable, Hashable, ChatLike {
 
     public var id: ChatId { get { chatInfo.id } }
 
+    public init(chatInfo: ChatInfo, chatItems: [ChatItem], chatStats: ChatStats = ChatStats()) {
+        self.chatInfo = chatInfo
+        self.chatItems = chatItems
+        self.chatStats = chatStats
+    }
+    
     public static func invalidJSON(_ json: String) -> ChatData {
         ChatData(
             chatInfo: .invalidJSON(json: json),