mobile: onboarding (#618)

* mobile: onboarding

* ios onboarding: create profile and make connection

* how SimpleX works

* connect via link

* remove separate view for connecting via link, fix bugs

* remove unused files

* fix help on small screens, update how it works page

* layout

* add About to settings, tidy up

* rename function

* update layout

* translations

* translation corrections

Co-authored-by: JRoberts <8711996+jr-simplex@users.noreply.github.com>

* correction

Co-authored-by: JRoberts <8711996+jr-simplex@users.noreply.github.com>

* corrections

Co-authored-by: JRoberts <8711996+jr-simplex@users.noreply.github.com>

* fix translations/layout

Co-authored-by: JRoberts <8711996+jr-simplex@users.noreply.github.com>

apps/ios/Shared/Model/SimpleXAPI.swift

@@ -10,6 +10,7 @@ import Foundation
 import UIKit
 import Dispatch
 import BackgroundTasks
+import SwiftUI
 
 private var chatController: chat_ctrl?
 
@@ -261,6 +262,16 @@ func apiConnect(connReq: String) async throws -> ConnReqType? {
             message: "Unless your contact deleted the connection or this link was already used, it might be a bug - please report it.\nTo connect, please ask your contact to create another connection link and check that you have a stable network connection."
         )
         return nil
+    case let .chatCmdError(.errorAgent(.INTERNAL(internalErr))):
+        if internalErr == "SEUniqueID" {
+            am.showAlertMsg(
+                title: "Already connected?",
+                message: "It seems like you are already connected via this link. If it is not the case, there was an error (\(responseError(r)))."
+            )
+            return nil
+        } else {
+            throw r
+        }
     default: throw r
     }
 }
@@ -424,13 +435,40 @@ private func sendCommandOkResp(_ cmd: ChatCommand) async throws {
 }
 
 func initializeChat() {
+    logger.debug("initializeChat")
     do {
-        ChatModel.shared.currentUser = try apiGetActiveUser()
+        let m = ChatModel.shared
+        m.currentUser = try apiGetActiveUser()
+        if m.currentUser == nil {
+            m.onboardingStage = .step1_SimpleXInfo
+        } else {
+            startChat()
+        }
     } catch {
         fatalError("Failed to initialize chat controller or database: \(error)")
     }
 }
 
+func startChat() {
+    logger.debug("startChat")
+    do {
+        let m = ChatModel.shared
+        try apiStartChat()
+        try apiSetFilesFolder(filesFolder: getAppFilesDirectory().path)
+        m.userAddress = try apiGetUserAddress()
+        m.userSMPServers = try getUserSMPServers()
+        m.chats = try apiGetChats()
+        withAnimation {
+            m.onboardingStage = m.chats.isEmpty
+                                ? .step3_MakeConnection
+                                : .onboardingComplete
+        }
+        ChatReceiver.shared.start()
+    } catch {
+        fatalError("Failed to start or load chats: \(error)")
+    }
+}
+
 class ChatReceiver {
     private var receiveLoop: Task<Void, Never>?
     private var receiveMessages = true