GODT-1917: gRPC service should use random port.

WIP: bridge-gui wait and parse gRPC service config fie.

internal/frontend/bridge-gui/bridgepp/bridgepp/GRPC/GRPCConfig.cpp

@@ -0,0 +1,133 @@
+// Copyright (c) 2022 Proton AG
+//
+// This file is part of Proton Mail Bridge.
+//
+// Proton Mail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Proton Mail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Proton Mail Bridge. If not, see <https://www.gnu.org/licenses/>.
+
+
+#include "GRPCConfig.h"
+#include "../Exception/Exception.h"
+
+
+using namespace bridgepp;
+
+
+namespace
+{
+
+Exception const invalidFileException("The service configuration file is invalid"); // Exception for invalid config.
+Exception const couldNotSaveException("The service configuration file could not be saved"); ///< Exception for write errors.
+QString const keyPort = "port"; ///< The JSON key for the port.
+QString const keyCert = "cert"; ///< The JSON key for the TLS certificate.
+QString const keyToken = "token"; ///< The JSON key for the identification token.
+
+
+//****************************************************************************************************************************************************
+/// \brief read a string value from a JSON object.
+///
+/// This function throws an Exception in case of error
+///
+/// \param[in] object The JSON object containing the value.
+/// \param[in] key The key under which the value is stored.
+//****************************************************************************************************************************************************
+QString jsonStringValue(QJsonObject const &object, QString const &key)
+{
+    QJsonValue const v = object[key];
+    if (!v.isString())
+        throw invalidFileException;
+    return v.toString();
+}
+
+
+//****************************************************************************************************************************************************
+/// \brief read a string value from a JSON object.
+///
+/// This function throws an Exception in case of error.
+///
+/// \param[in] object The JSON object containing the value.
+/// \param[in] key The key under which the value is stored.
+//****************************************************************************************************************************************************
+qint32 jsonIntValue(QJsonObject const &object, QString const &key)
+{
+    QJsonValue const v = object[key];
+    if (!v.isDouble())
+        throw invalidFileException;
+    return v.toInt();
+}
+
+
+} // anonymous namespace
+
+
+//****************************************************************************************************************************************************
+/// \param[in] path The path of the file to load from.
+/// \param[out] outError if not null and an error occurs, this variable contains a description of the error.
+/// \return true iff the operation was successful.
+//****************************************************************************************************************************************************
+bool GRPCConfig::load(QString const &path, QString *outError)
+{
+    try
+    {
+        QFile file(path);
+        if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
+            throw Exception("Could not open gRPC service config file.");
+
+        QJsonDocument const doc = QJsonDocument::fromJson(file.readAll());
+        QJsonObject const object = doc.object();
+        port = jsonIntValue(object, keyPort);
+        cert = jsonStringValue(object, keyCert);
+        token = jsonStringValue(object, keyToken);
+
+        return true;
+    }
+    catch (Exception const &e)
+    {
+        if (outError)
+            *outError = e.qwhat();
+        return false;
+    }
+}
+
+
+//****************************************************************************************************************************************************
+/// \param[in] path The path of the file to write to.
+/// \param[out] outError if not null and an error occurs, this variable contains a description of the error.
+/// \return true iff the operation was successful.
+//****************************************************************************************************************************************************
+bool GRPCConfig::save(QString const &path, QString *outError)
+{
+    try
+    {
+        QJsonObject const object;
+        object[keyPort] = port;
+        object[keyCert] = cert;
+        object[keyToken] = token;
+
+        QFile file(path);
+        if (!file.open(QIODevice::WriteOnly | QIODevice::Text))
+            throw couldNotSaveException;
+
+        QByteArray const array = QJsonDocument(object).toJson();
+        if (array.size() != file.write(array))
+            throw couldNotSaveException;
+
+        return true;
+    }
+    catch (Exception const &e)
+    {
+        if (outError)
+            *outError = e.qwhat();
+        return false;
+    }
+}