From d5414631c398d24ec3d6278af5ddc75d0ed0e6a4 Mon Sep 17 00:00:00 2001
From: Eugene Shalygin <eugene.shalygin@gmail.com>
Date: Tue, 10 May 2016 14:49:19 +0200
Subject: [PATCH] Initialise QBtCommandLineParameters members from environment

This allows to pass options via environment variables. The variable name
is constructed from parameter name by transforming the name to upper
case and prefixing "QBT_".
---
 src/app/options.cpp | 52 ++++++++++++++++++++++++++++++++++++---------
 src/app/options.h   |  4 +++-
 2 files changed, 45 insertions(+), 11 deletions(-)

diff --git a/src/app/options.cpp b/src/app/options.cpp
index af9e63c03..57c673753 100644
--- a/src/app/options.cpp
+++ b/src/app/options.cpp
@@ -33,7 +33,10 @@
 #include "options.h"
 
 #include <iostream>
+
+#include <QDebug>
 #include <QFileInfo>
+#include <QProcessEnvironment>
 
 #ifdef Q_OS_WIN
 #include <QMessageBox>
@@ -41,26 +44,56 @@
 
 #include "base/utils/misc.h"
 
-QBtCommandLineParameters::QBtCommandLineParameters()
+namespace
+{
+    bool isBoolEnvVarSetToTrue(const QProcessEnvironment &env, const QString &var)
+    {
+        QString val = env.value(var);
+        // we accept "1" and "true" (upper or lower cased) as boolean 'true' values
+        return (val == QLatin1String("1") || val.toUpper() == QLatin1String("TRUE"));
+    }
+
+    int readIntlEnvVar(const QProcessEnvironment &env, const QString &var, int defaultValue)
+    {
+        QString val = env.value(var);
+        if (val.isEmpty()) return defaultValue;
+        bool ok;
+        int res = val.toInt(&ok);
+        if (!ok) {
+            qDebug() << QObject::tr("Expected integer number in environment variable '%1', but got '%2'")
+                .arg(var).arg(val);
+            return defaultValue;
+        }
+        return res;
+    }
+
+    QString envVarNameForParameter(const char *parameterName)
+    {
+        return QLatin1String("QBT_") +
+               QString(QLatin1String(parameterName)).toUpper().replace(QLatin1Char('-'), QLatin1Char('_'));
+    }
+}
+
+QBtCommandLineParameters::QBtCommandLineParameters(const QProcessEnvironment &env)
     : showHelp(false)
 #ifndef Q_OS_WIN
     , showVersion(false)
 #endif
 #ifndef DISABLE_GUI
-    , noSplash(false)
+    , noSplash(isBoolEnvVarSetToTrue(env, envVarNameForParameter("no-splash")))
 #else
-    , shouldDaemonize(false)
+    , shouldDaemonize(isBoolEnvVarSetToTrue(env, envVarNameForParameter("daemon")))
 #endif
-    , webUiPort(-1)
-    , profileDir()
-    , portableMode(false)
-    , configurationName()
+    , webUiPort(readIntlEnvVar(env, envVarNameForParameter("webui-port"), -1))
+    , profileDir(env.value(envVarNameForParameter("profile")))
+    , portableMode(isBoolEnvVarSetToTrue(env, envVarNameForParameter("portable")))
+    , configurationName(env.value(envVarNameForParameter("configuration")))
 {
 }
 
 QBtCommandLineParameters parseCommandLine(const QStringList &args)
 {
-    QBtCommandLineParameters result;
+    QBtCommandLineParameters result {QProcessEnvironment::systemEnvironment()};
 
     for (int i = 1; i < args.count(); ++i) {
         const QString &arg = args[i];
@@ -178,7 +211,7 @@ QString makeUsage(const QString &prgName)
     return text;
 }
 
-void displayUsage(const QString& prgName)
+void displayUsage(const QString &prgName)
 {
 #ifndef Q_OS_WIN
     std::cout << qPrintable(makeUsage(prgName)) << std::endl;
@@ -189,4 +222,3 @@ void displayUsage(const QString& prgName)
     msgBox.exec();
 #endif
 }
-
diff --git a/src/app/options.h b/src/app/options.h
index 56724fc3b..2c1e2d67b 100644
--- a/src/app/options.h
+++ b/src/app/options.h
@@ -38,6 +38,8 @@
 #include <QString>
 #include <QStringList>
 
+class QProcessEnvironment;
+
 struct QBtCommandLineParameters
 {
     bool showHelp;
@@ -56,7 +58,7 @@ struct QBtCommandLineParameters
     QStringList torrents;
     QString unknownParameter;
 
-    QBtCommandLineParameters();
+    QBtCommandLineParameters(const QProcessEnvironment&);
 };
 
 class CommandLineParameterError: public std::runtime_error