GODT-1893: bridge-gui sends bridge's log to stdout, stderr.

WIP: bridge-gui now parses and self-apply log level from command-line.
WIP: downgraded the log level of gRPC calls to debug.

internal/frontend/bridge-gui/bridge-gui/CommandLine.cpp

@@ -0,0 +1,129 @@
+// 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 "Pch.h"
+#include "CommandLine.h"
+
+
+using namespace bridgepp;
+
+
+namespace
+{
+
+
+QString const launcherFlag = "--launcher"; ///< launcher flag parameter used for bridge.
+
+
+//****************************************************************************************************************************************************
+/// \brief parse a command-line string argument as expected by go's CLI package.
+/// \param[in] argc The number of arguments passed to the application.
+/// \param[in] argv The list of arguments passed to the application.
+/// \param[in] paramNames the list of names for the parameter
+//****************************************************************************************************************************************************
+QString parseGoCLIStringArgument(int argc, char *argv[], QStringList paramNames)
+{
+    // go cli package is pretty permissive when it comes to parsing arguments. For each name 'param', all the following seems to be accepted:
+    // -param value
+    // --param value
+    // -param=value
+    // --param=value
+
+    for (QString const &paramName: paramNames)
+        for (qsizetype i = 1; i < argc; ++i)
+        {
+            QString const arg(QString::fromLocal8Bit(argv[i]));
+            if ((i < argc - 1) && ((arg == "-" + paramName) || (arg == "--" + paramName)))
+                return QString(argv[i + 1]);
+
+            QRegularExpressionMatch match = QRegularExpression(QString("^-{1,2}%1=(.+)$").arg(paramName)).match(arg);
+            if (match.hasMatch())
+                return match.captured(1);
+        }
+
+    return QString();
+}
+
+
+//****************************************************************************************************************************************************
+/// \brief Parse the log level from the command-line arguments.
+///
+/// \param[in] argc The number of arguments passed to the application.
+/// \param[in] argv The list of arguments passed to the application.
+/// \return The log level. if not specified on the command-line, the default log level is returned.
+//****************************************************************************************************************************************************
+Log::Level parseLogLevel(int argc, char *argv[])
+{
+    QString levelStr = parseGoCLIStringArgument(argc, argv, { "l", "log-level" });
+    if (levelStr.isEmpty())
+        return Log::defaultLevel;
+
+    Log::Level level = Log::defaultLevel;
+    Log::stringToLevel(levelStr, level);
+    return level;
+}
+
+
+} // anonymous namespace
+
+
+//****************************************************************************************************************************************************
+/// \param[in]  argc number of arguments passed to the application.
+/// \param[in]  argv list of arguments passed to the application.
+/// \param[out] args list of arguments passed to the application as a QStringList.
+/// \param[out] launcher launcher used in argument, forced to self application if not specify.
+/// \param[out] outAttach The value for the 'attach' command-line parameter.
+/// \param[out] outLogLevel The parsed log level. If not found, the default log level is returned.
+//****************************************************************************************************************************************************
+void parseCommandLineArguments(int argc, char *argv[], QStringList& args, QString& launcher, bool &outAttach, Log::Level& outLogLevel) {
+    bool flagFound = false;
+    launcher = QString::fromLocal8Bit(argv[0]);
+    // for unknown reasons, on Windows QCoreApplication::arguments() frequently returns an empty list, which is incorrect, so we rebuild the argument
+    // list from the original argc and argv values.
+    for (int i = 1; i < argc; i++) {
+        QString const &arg = QString::fromLocal8Bit(argv[i]);
+        // we can't use QCommandLineParser here since it will fail on unknown options.
+        // Arguments may contain some bridge flags.
+        if (arg == launcherFlag)
+        {
+            args.append(arg);
+            launcher = QString::fromLocal8Bit(argv[++i]);
+            args.append(launcher);
+            flagFound = true;
+        }
+#ifdef QT_DEBUG
+        else if (arg == "--attach" || arg == "-a")
+        {
+            // we don't keep the attach mode within the args since we don't need it for Bridge.
+            outAttach = true;
+        }
+#endif
+        else
+        {
+            args.append(arg);
+        }
+    }
+    if (!flagFound)
+    {
+        // add bridge-gui as launcher
+        args.append(launcherFlag);
+        args.append(launcher);
+    }
+
+    outLogLevel = parseLogLevel(argc, argv);
+}