Include more error messaging for failed image uploads (#4096)

src/util/NuulsUploader.cpp

@@ -204,9 +204,32 @@ void uploadImageToNuuls(RawImageData imageData, ChannelPtr channel,
             return Success;
         })
         .onError([channel](NetworkResult result) -> bool {
-            channel->addMessage(makeSystemMessage(
+            auto errorMessage =
                 QString("An error happened while uploading your image: %1")
-                    .arg(result.status())));
+                    .arg(result.status());
+
+            // Try to read more information from the result body
+            auto obj = result.parseJson();
+            if (!obj.isEmpty())
+            {
+                auto apiCode = obj.value("code");
+                if (!apiCode.isUndefined())
+                {
+                    auto codeString = apiCode.toVariant().toString();
+                    codeString.truncate(20);
+                    errorMessage += QString(" - code: %1").arg(codeString);
+                }
+
+                auto apiError = obj.value("error").toString();
+                if (!apiError.isEmpty())
+                {
+                    apiError.truncate(300);
+                    errorMessage +=
+                        QString(" - error: %1").arg(apiError.trimmed());
+                }
+            }
+
+            channel->addMessage(makeSystemMessage(errorMessage));
             uploadMutex.unlock();
             return true;
         })