/*
 * Bittorrent Client using Qt and libtorrent.
 * Copyright (C) 2016  Eugene Shalygin <eugene.shalygin@gmail.com>
 * Copyright (C) 2014  Vladimir Golovnev <glassez@yandex.ru>
 * Copyright (C) 2006  Christophe Dumez
 *
 * This program 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 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * In addition, as a special exception, the copyright holders give permission to
 * link this program with the OpenSSL project's "OpenSSL" library (or with
 * modified versions of it that use the same license as the "OpenSSL" library),
 * and distribute the linked executables. You must obey the GNU General Public
 * License in all respects for all of the code used other than "OpenSSL".  If you
 * modify file(s), you may extend this exception to your version of the file(s),
 * but you are not obligated to do so. If you do not wish to do so, delete this
 * exception statement from your version.
 *
 * Contact : chris@qbittorrent.org
 */

#include "options.h"

#include <iostream>

#include <QDebug>
#include <QFileInfo>
#include <QProcessEnvironment>
#include <QTextStream>

#ifdef Q_OS_WIN
#include <QMessageBox>
#endif

#include "base/utils/misc.h"

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(isBoolEnvVarSetToTrue(env, envVarNameForParameter("no-splash")))
#else
    , shouldDaemonize(isBoolEnvVarSetToTrue(env, envVarNameForParameter("daemon")))
#endif
    , 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 {QProcessEnvironment::systemEnvironment()};

    for (int i = 1; i < args.count(); ++i) {
        const QString &arg = args[i];

        if ((arg.startsWith("--") && !arg.endsWith(".torrent"))
            || (arg.startsWith("-") && (arg.size() == 2))) {
            // Parse known parameters
            if ((arg == QLatin1String("-h")) || (arg == QLatin1String("--help"))) {
                result.showHelp = true;
            }
#ifndef Q_OS_WIN
            else if ((arg == QLatin1String("-v")) || (arg == QLatin1String("--version"))) {
                result.showVersion = true;
            }
#endif
            else if (arg.startsWith(QLatin1String("--webui-port="))) {
                QStringList parts = arg.split(QLatin1Char('='));
                if (parts.size() == 2) {
                    bool ok = false;
                    result.webUiPort = parts.last().toInt(&ok);
                    if (!ok || (result.webUiPort < 1) || (result.webUiPort > 65535))
                        throw CommandLineParameterError(QObject::tr("%1 must specify the correct port (1 to 65535).")
                                                        .arg(QLatin1String("--webui-port")));
                }
            }
#ifndef DISABLE_GUI
            else if (arg == QLatin1String("--no-splash")) {
                result.noSplash = true;
            }
#else
            else if ((arg == QLatin1String("-d")) || (arg == QLatin1String("--daemon"))) {
                result.shouldDaemonize = true;
            }
#endif
            else if (arg == QLatin1String("--profile")) {
                QStringList parts = arg.split(QLatin1Char('='));
                if (parts.size() == 2)
                    result.profileDir = parts.last();
            }
            else if (arg == QLatin1String("--portable")) {
                result.portableMode = true;
            }
            else if (arg == QLatin1String("--configuration")) {
                QStringList parts = arg.split(QLatin1Char('='));
                if (parts.size() == 2)
                    result.configurationName = parts.last();
            }
            else {
                // Unknown argument
                result.unknownParameter = arg;
                break;
            }
        }
        else {
            QFileInfo torrentPath;
            torrentPath.setFile(arg);

            if (torrentPath.exists())
                result.torrents += torrentPath.absoluteFilePath();
            else
                result.torrents += arg;
        }
    }

    return result;
}

CommandLineParameterError::CommandLineParameterError(const QString &messageForUser)
    : std::runtime_error(messageForUser.toLocal8Bit().data())
    , m_messageForUser(messageForUser)
{
}

const QString& CommandLineParameterError::messageForUser() const
{
    return m_messageForUser;
}

QString makeUsage(const QString &prgName)
{
    QString text;
    QTextStream stream(&text, QIODevice::WriteOnly);

    stream << QObject::tr("Usage:") << '\n';
#ifndef Q_OS_WIN
    stream << '\t' << prgName << " [options] [(<filename> | <url>)...]" << '\n';
#endif

    stream << QObject::tr("Options:") << '\n';
#ifndef Q_OS_WIN
    stream << "\t-v | --version\t\t" << QObject::tr("Displays program version and exit") << '\n';
#endif
    stream << "\t-h | --help\t\t" << QObject::tr("Displays this help message and exit") << '\n';
    stream << "\t--webui-port=<port>\t"
           << QObject::tr("Changes the Web UI port")
           << '\n';
#ifndef DISABLE_GUI
    stream << "\t--no-splash\t\t" << QObject::tr("Disable splash screen") << '\n';
#else
    stream << "\t-d | --daemon\t\t" << QObject::tr("Run in daemon-mode (background)") << '\n';
#endif
    stream << "\t--profile=<dir>\t\t" << QObject::tr("Store configuration files in <dir>") << '\n';
    stream << "\t--portable\t\t" << QObject::tr("Shortcut for --profile=<exe dir>/profile") << '\n';
    stream << "\t--configuration=<name>\t" << QObject::tr("Store configuration files in directories qBittorrent_<name>")
           << '\n';
    stream << "\tfiles or urls\t\t" << QObject::tr("Downloads the torrents passed by the user") << '\n'
           << '\n';

    stream << QObject::tr("Option values may be supplied via environment variables.") << '\n'
           << QObject::tr("For option named 'parameter-name', environment variable name is 'QBT_PARAMETER_NAME' (in upper case, '-' replaced with '_')") << '\n'
           << QObject::tr("To pass flag values, set the variable to '1' or 'TRUE'.") << '\n'
           << QObject::tr("For example, to disable the splash screen: ")
           << "QBT_NO_SPLASH=1 " << prgName << '\n'
           << '\n'
           << QObject::tr("Command line parameters take precedence over environment variables") << '\n';

    stream << flush;
    return text;
}

void displayUsage(const QString &prgName)
{
#ifndef Q_OS_WIN
    std::cout << qPrintable(makeUsage(prgName)) << std::endl;
#else
    QMessageBox msgBox(QMessageBox::Information, QObject::tr("Help"), makeUsage(prgName), QMessageBox::Ok);
    msgBox.show(); // Need to be shown or to moveToCenter does not work
    msgBox.move(Utils::Misc::screenCenter(&msgBox));
    msgBox.exec();
#endif
}