From ba3d74a9c54ebed301c995bbfee4a51de5cf7eae Mon Sep 17 00:00:00 2001
From: Nuno Vieira <nuno.fcvieira93@gmail.com>
Date: Fri, 8 Dec 2023 18:30:23 +0000
Subject: [PATCH] Make Internet Connection Monitor safer (#2923)

* Use serial queue for NWPathMonitor instead of the global queue

* Remove Legacy Network Monitor since we now support iOS 12+ only

* Update CHANGELOG.md
---
 CHANGELOG.md                                  |  1 +
 Package.swift                                 |  2 +-
 .../StreamChat/ChatClient+Environment.swift   |  4 +-
 .../InternetConnection.swift                  | 86 +------------------
 4 files changed, 5 insertions(+), 88 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9807bf2424..4bc492fd46 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### 🐞 Fixed
 - Fix `UserInfo.isInvisible` not nullable [#2920](https://github.com/GetStream/stream-chat-swift/pull/2920)
 - Fix CocoaPods minimum iOS target not in sync with the Xcode project [#2924](https://github.com/GetStream/stream-chat-swift/pull/2924)
+- Improve `InternetConnection.Monitor` stability [#2923](https://github.com/GetStream/stream-chat-swift/pull/2923)
 ### 🔄 Changed
 - The `UserInfo.isInvisible` is now nullable and `nil` by default [#2920](https://github.com/GetStream/stream-chat-swift/pull/2920)
 
diff --git a/Package.swift b/Package.swift
index 892280d6b0..0373d3a204 100644
--- a/Package.swift
+++ b/Package.swift
@@ -7,7 +7,7 @@ let package = Package(
     name: "StreamChat",
     defaultLocalization: "en",
     platforms: [
-        .iOS(.v11), .macOS(.v10_15)
+        .iOS(.v12), .macOS(.v10_15)
     ],
     products: [
         .library(
diff --git a/Sources/StreamChat/ChatClient+Environment.swift b/Sources/StreamChat/ChatClient+Environment.swift
index fd604747a9..4882ba7b7c 100644
--- a/Sources/StreamChat/ChatClient+Environment.swift
+++ b/Sources/StreamChat/ChatClient+Environment.swift
@@ -69,10 +69,8 @@ extension ChatClient {
         var internetMonitor: InternetConnectionMonitor {
             if let monitor = monitor {
                 return monitor
-            } else if #available(iOS 12, *) {
-                return InternetConnection.Monitor()
             } else {
-                return InternetConnection.LegacyMonitor()
+                return InternetConnection.Monitor()
             }
         }
 
diff --git a/Sources/StreamChat/Utils/InternetConnection/InternetConnection.swift b/Sources/StreamChat/Utils/InternetConnection/InternetConnection.swift
index fbbe953db2..e08c386e6a 100644
--- a/Sources/StreamChat/Utils/InternetConnection/InternetConnection.swift
+++ b/Sources/StreamChat/Utils/InternetConnection/InternetConnection.swift
@@ -149,11 +149,9 @@ extension InternetConnection.Status {
 // MARK: - Internet Connection Monitor
 
 extension InternetConnection {
-    /// The default Internet connection monitor for iOS 12+.
-    /// It uses Apple Network API.
-    @available(iOS 12, *)
     class Monitor: InternetConnectionMonitor {
         private var monitor: NWPathMonitor?
+        private let queue = DispatchQueue(label: "io.getstream.internet-monitor")
 
         weak var delegate: InternetConnectionDelegate?
 
@@ -169,7 +167,7 @@ extension InternetConnection {
             guard monitor == nil else { return }
 
             monitor = createMonitor()
-            monitor?.start(queue: .global())
+            monitor?.start(queue: queue)
         }
 
         func stop() {
@@ -214,83 +212,3 @@ extension InternetConnection {
         }
     }
 }
-
-// MARK: Legacy Internet Connection Monitor for iOS 11 only
-
-extension InternetConnection {
-    class LegacyMonitor: InternetConnectionMonitor {
-        /// A Reachability instance for Internet connection monitoring.
-        private lazy var reachability = createReachability()
-
-        weak var delegate: InternetConnectionDelegate?
-
-        var status: InternetConnection.Status {
-            if let reachability = reachability {
-                return status(from: reachability)
-            }
-
-            return .unknown
-        }
-
-        func start() {
-            do {
-                try reachability?.startNotifier()
-            } catch {
-                log.error(error)
-            }
-        }
-
-        func stop() {
-            reachability?.stopNotifier()
-        }
-
-        private func createReachability() -> Reachability? {
-            var reachability: Reachability?
-
-            do {
-                reachability = try Reachability()
-                reachability?.whenReachable = { [weak self] in self?.updateStatus(with: $0) }
-                reachability?.whenUnreachable = { [weak self] in self?.updateStatus(with: $0) }
-            } catch {
-                log.error(error)
-            }
-
-            return reachability
-        }
-
-        private func updateStatus(with reachability: Reachability) {
-            log.info("Internet Connection info: \(reachability.description)")
-
-            if case .unavailable = reachability.connection {
-                delegate?.internetConnectionStatusDidChange(status: .unavailable)
-                return
-            }
-
-            let quality: InternetConnection.Quality
-
-            if case .cellular = reachability.connection {
-                quality = .expensive
-            } else {
-                quality = .great
-            }
-
-            delegate?.internetConnectionStatusDidChange(status: .available(quality))
-        }
-
-        private func status(from reachability: Reachability) -> InternetConnection.Status {
-            if case .unavailable = reachability.connection {
-                return .unavailable
-            }
-
-            let quality: InternetConnection.Quality
-
-            if case .cellular = reachability.connection {
-                quality = .expensive
-            } else {
-                quality = .great
-            }
-
-            return .available(quality)
-        }
-    }
-}