ios: reduce memory used by iOS share extension (#6465)

apps/ios/SimpleX SE/ShareAPI.swift

@@ -48,7 +48,7 @@ func apiSetEncryptLocalFiles(_ enable: Bool) throws {
     throw r.unexpected
 }
 
-func apiGetChats(userId: User.ID) throws -> Array<ChatData> {
+func apiGetChats(userId: User.ID) throws -> Array<SEChatData> {
     let r: APIResult<SEChatResponse> = sendSimpleXCmd(SEChatCommand.apiGetChats(userId: userId))
     if case let .result(.apiChats(user: _, chats: chats)) = r { return chats }
     throw r.unexpected
@@ -170,7 +170,7 @@ enum SEChatResponse: Decodable, ChatAPIResult {
     case activeUser(user: User)
     case chatStarted
     case chatRunning
-    case apiChats(user: UserRef, chats: [ChatData])
+    case apiChats(user: UserRef, chats: [SEChatData])
     case newChatItems(user: UserRef, chatItems: [AChatItem])
     case cmdOk(user_: UserRef?)
     
@@ -199,7 +199,7 @@ enum SEChatResponse: Decodable, ChatAPIResult {
     }
 
     static func fallbackResult(_ type: String, _ json: NSDictionary) -> SEChatResponse? {
-        if type == "apiChats", let r = parseApiChats(json) {
+        if type == "apiChats", let r = seParseApiChats(json) {
             .apiChats(user: r.user, chats: r.chats)
         } else {
             nil
@@ -239,3 +239,35 @@ enum SEChatEvent: Decodable, ChatAPIResult {
         }
     }    
 }
+
+public struct SEChatData: Decodable, Identifiable, Hashable, ChatLike {
+    public var chatInfo: ChatInfo
+
+    public var id: ChatId { get { chatInfo.id } }
+
+    public init(chatInfo: ChatInfo) {
+        self.chatInfo = chatInfo
+    }
+
+    public static func invalidJSON(_ json: Data?) -> SEChatData {
+        SEChatData(chatInfo: .invalidJSON(json: json))
+    }
+}
+
+public func seParseApiChats(_ jResp: NSDictionary) -> (user: UserRef, chats: [SEChatData])? {
+    if let jApiChats = jResp["apiChats"] as? NSDictionary,
+       let user: UserRef = try? decodeObject(jApiChats["user"] as Any),
+       let jChats = jApiChats["chats"] as? NSArray {
+        let chats: [SEChatData] = jChats.map { jChat in
+            if let jChatDict = jChat as? NSDictionary,
+               let jChatInfo = jChatDict["chatInfo"],
+               let chatInfo: ChatInfo = try? decodeObject(jChatInfo) {
+                return SEChatData(chatInfo: chatInfo)
+            }
+            return SEChatData.invalidJSON(serializeJSON(jChat, options: .prettyPrinted))
+        }
+        return (user, chats)
+    } else {
+        return nil
+    }
+}

apps/ios/SimpleX SE/ShareModel.swift

@@ -19,11 +19,11 @@ private let MAX_DOWNSAMPLE_SIZE: Int64 = 2000
 
 class ShareModel: ObservableObject {
     @Published var sharedContent: SharedContent?
-    @Published var chats: [ChatData] = []
+    @Published var chats: [SEChatData] = []
     @Published var profileImages: [ChatInfo.ID: UIImage] = [:]
     @Published var search = ""
     @Published var comment = ""
-    @Published var selected: ChatData?
+    @Published var selected: SEChatData?
     @Published var isLoaded = false
     @Published var bottomBar: BottomBar = .loadingSpinner
     @Published var errorAlert: ErrorAlert?
@@ -60,13 +60,13 @@ class ShareModel: ObservableObject {
         }
     }
 
-    func isProhibited(_ chat: ChatData?) -> Bool {
+    func isProhibited(_ chat: SEChatData?) -> Bool {
         if let chat, let sharedContent {
             sharedContent.prohibited(in: chat, hasSimplexLink: hasSimplexLink)
         } else { false }
     }
 
-    var filteredChats: [ChatData] {
+    var filteredChats: [SEChatData] {
         search.isEmpty
         ? filterChatsToForwardTo(chats: chats)
         : filterChatsToForwardTo(chats: chats)
@@ -253,7 +253,7 @@ class ShareModel: ObservableObject {
         }
     }
     
-    private func fetchChats() -> Result<Array<ChatData>, ErrorAlert> {
+    private func fetchChats() -> Result<Array<SEChatData>, ErrorAlert> {
         do {
             guard let user = try apiGetActiveUser() else {
                 return .failure(
@@ -396,7 +396,7 @@ enum SharedContent {
         }
     }
 
-    func prohibited(in chatData: ChatData, hasSimplexLink: Bool) -> Bool {
+    func prohibited(in chatData: SEChatData, hasSimplexLink: Bool) -> Bool {
         chatData.prohibitedByPref(
             hasSimplexLink: hasSimplexLink,
             isMediaOrFileAttachment: cryptoFile != nil,

apps/ios/SimpleXChat/ChatUtils.swift

@@ -9,9 +9,7 @@
 import Foundation
 
 public protocol ChatLike {
-    var chatInfo: ChatInfo { get}
-    var chatItems: [ChatItem] { get }
-    var chatStats: ChatStats { get }
+    var chatInfo: ChatInfo { get }
 }
 
 extension ChatLike {