Improve network error messages (#4704)

src/common/NetworkResult.hpp

@@ -2,14 +2,20 @@
 
 #include <QJsonArray>
 #include <QJsonObject>
+#include <QNetworkReply>
 #include <rapidjson/document.h>
 
+#include <optional>
+
 namespace chatterino {
 
 class NetworkResult
 {
 public:
-    NetworkResult(const QByteArray &data, int status);
+    using NetworkError = QNetworkReply::NetworkError;
+
+    NetworkResult(NetworkError error, const QVariant &httpStatusCode,
+                  QByteArray data);
 
     /// Parses the result as json and returns the root as an object.
     /// Returns empty object if parsing failed.
@@ -20,13 +26,29 @@ public:
     /// Parses the result as json and returns the document.
     rapidjson::Document parseRapidJson() const;
     const QByteArray &getData() const;
-    int status() const;
 
-    static constexpr int timedoutStatus = -2;
+    /// The error code of the reply.
+    /// In case of a successful reply, this will be NoError (0)
+    NetworkError error() const
+    {
+        return this->error_;
+    }
+
+    /// The HTTP status code if a response was received.
+    std::optional<int> status() const
+    {
+        return this->status_;
+    }
+
+    /// Formats the error.
+    /// If a reply is received, returns the HTTP status otherwise, the network error.
+    QString formatError() const;
 
 private:
     QByteArray data_;
-    int status_;
+
+    NetworkError error_;
+    std::optional<int> status_;
 };
 
 }  // namespace chatterino