Log more when unknown error returned on iOS

It is useful to know more details in further investigation in
what circumstances unknown error has been returned like exact
status code, background or foreground, etc

Relates-To: OCMAM-494

Author: rustam-gamidov-here

olp-cpp-sdk-core/src/http/ios/OLPHttpClient.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2019-2023 HERE Europe B.V.
+ * Copyright (C) 2019-2025 HERE Europe B.V.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,8 @@
 
 #import <Foundation/Foundation.h>
 
+#include <string>
+
 #include "olp/core/http/NetworkTypes.h"
 
 @class OLPHttpTask;
@@ -54,6 +56,9 @@ class NetworkProxySettings;
 /// Cancel the task with corresponding request id
 - (void)cancelTaskWithId:(olp::http::RequestId)identifier;
 
+/// Get information related to the task with corresponding request id
+- (std::string)getInfoForTaskWithId:(olp::http::RequestId)identifier;
+
 /// Finish all tasks in progress and invalidate all URL sessions
 - (void)cleanup;
 

olp-cpp-sdk-core/src/http/ios/OLPHttpClient.mm

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2019-2024 HERE Europe B.V.
+ * Copyright (C) 2019-2025 HERE Europe B.V.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,8 @@
 #import <CommonCrypto/CommonDigest.h>
 #import <Security/Security.h>
 
+#include <sstream>
+
 #include "context/ContextInternal.h"
 #include "olp/core/context/EnterBackgroundSubscriber.h"
 #include "olp/core/http/Network.h"
@@ -34,7 +36,7 @@
 constexpr auto kMaximumConnectionPerHost = 32;
 
 using SessionId = std::uint64_t;
-static SessionId sessionIdCounter_ = std::numeric_limits<SessionId>::min() + 1;
+static SessionId sessionIdCounter_ = std::time(nullptr);
 
 class EnterBackgroundSubscriberImpl
     : public olp::context::EnterBackgroundSubscriber {
@@ -280,6 +282,36 @@ - (void)removeTaskWithId:(olp::http::RequestId)identifier {
   }
 }
 
+- (std::string)getInfoForTaskWithId:(olp::http::RequestId)identifier {
+  @synchronized(_tasks) {
+    OLPHttpTask* task = _tasks[@(identifier)];
+    std::stringstream out;
+
+    NSNumber* requestId = @(identifier);
+    NSURLSession* session = self.urlSessions[requestId];
+
+    if (!task.dataTask) {
+      out << "no http task in _tasks for request_id=" << identifier;
+      return out.str();
+    }
+
+    const auto get_session_config_id = [&]() {
+      if (session && session.configuration &&
+          session.configuration.identifier) {
+        return [session.configuration.identifier UTF8String];
+      }
+      return "<not set>";
+    };
+
+    out << "request_id=" << identifier << ", httpTask=" << (__bridge void*)task
+        << ", backgroundMode=" << task.backgroundMode
+        << ", dataTask=" << (__bridge void*)task.dataTask
+        << ", session=" << (__bridge void*)session
+        << ", session_config_id=" << get_session_config_id();
+    return out.str();
+  }
+}
+
 #pragma mark - NSURLSessionDataDelegate
 
 - (void)URLSession:(NSURLSession*)session

olp-cpp-sdk-core/src/http/ios/OLPNetworkIOS.mm

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2019-2024 HERE Europe B.V.
+ * Copyright (C) 2019-2025 HERE Europe B.V.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -159,9 +159,8 @@
       task = [http_client_ createTaskWithProxy:proxy_settings andId:request_id];
     }
     if (!task) {
-      OLP_SDK_LOG_WARNING_F(kLogTag,
-                            "Send failed - can't create task for url=%s",
-                            request.GetUrl().c_str());
+      OLP_SDK_LOG_ERROR_F(kLogTag, "Send failed - can't create task for url=%s",
+                          request.GetUrl().c_str());
       return SendOutcome(ErrorCode::UNKNOWN_ERROR);
     }
 
@@ -317,9 +316,20 @@
         if (error && !cancelled) {
           error_str = status < 0
                           ? std::string(error.localizedDescription.UTF8String)
-                          : "Failure";
+                          : "Failure, error.code = " + std::to_string(status);
           status =
               static_cast<int>(ConvertNSURLErrorToNetworkErrorCode(error.code));
+
+          if (status == static_cast<int>(ErrorCode::UNKNOWN_ERROR)) {
+            std::string task_info =
+                [http_client_ getInfoForTaskWithId:strong_task.requestId];
+
+            OLP_SDK_LOG_ERROR_F(kLogTag,
+                                "Task returned unknown error; error_str=%s, "
+                                "task_info: %s, url=%s",
+                                error_str.c_str(), task_info.c_str(),
+                                request.GetUrl().c_str());
+          }
         } else {
           status = cancelled ? static_cast<int>(ErrorCode::CANCELLED_ERROR)
                              : response_data.status;