/* Copyright 2013-2019 MultiMC Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "LauncherPartLaunch.h"
#include <QCoreApplication>
#include <launch/LaunchTask.h>
#include <minecraft/MinecraftInstance.h>
#include <FileSystem.h>
#include <Commandline.h>
#include <QStandardPaths>
#include "Env.h"

LauncherPartLaunch::LauncherPartLaunch(LaunchTask *parent) : LaunchStep(parent)
{
    connect(&m_process, &LoggedProcess::log, this, &LauncherPartLaunch::logLines);
    connect(&m_process, &LoggedProcess::stateChanged, this, &LauncherPartLaunch::on_state);
}

#ifdef Q_OS_WIN
// returns 8.3 file format from long path
#include <windows.h>
QString shortPathName(const QString & file)
{
    auto input = file.toStdWString();
    std::wstring output;
    long length = GetShortPathNameW(input.c_str(), NULL, 0);
    // NOTE: this resizing might seem weird...
    // when GetShortPathNameW fails, it returns length including null character
    // when it succeeds, it returns length excluding null character
    // See: https://msdn.microsoft.com/en-us/library/windows/desktop/aa364989(v=vs.85).aspx
    output.resize(length);
    GetShortPathNameW(input.c_str(),(LPWSTR)output.c_str(),length);
    output.resize(length-1);
    QString ret = QString::fromStdWString(output);
    return ret;
}
#endif

// if the string survives roundtrip through local 8bit encoding...
bool fitsInLocal8bit(const QString & string)
{
    return string == QString::fromLocal8Bit(string.toLocal8Bit());
}

void LauncherPartLaunch::executeTask()
{
    auto instance = m_parent->instance();
    std::shared_ptr<MinecraftInstance> minecraftInstance = std::dynamic_pointer_cast<MinecraftInstance>(instance);

    m_launchScript = minecraftInstance->createLaunchScript(m_session);
    QStringList args = minecraftInstance->javaArguments();
    QString allArgs = args.join(", ");
    emit logLine("Java Arguments:\n[" + m_parent->censorPrivateInfo(allArgs) + "]\n\n", MessageLevel::MultiMC);

    auto javaPath = FS::ResolveExecutable(instance->settings()->get("JavaPath").toString());

    m_process.setProcessEnvironment(instance->createEnvironment());

    // make detachable - this will keep the process running even if the object is destroyed
    m_process.setDetachable(true);

    auto classPath = minecraftInstance->getClassPath();
    classPath.prepend(FS::PathCombine(ENV.getJarsPath(), "NewLaunch.jar"));

    auto natPath = minecraftInstance->getNativePath();
#ifdef Q_OS_WIN
    if (!fitsInLocal8bit(natPath))
    {
        args << "-Djava.library.path=" + shortPathName(natPath);
    }
    else
    {
        args << "-Djava.library.path=" + natPath;
    }
#else
    args << "-Djava.library.path=" + natPath;
#endif

    args << "-cp";
#ifdef Q_OS_WIN
    QStringList processed;
    for(auto & item: classPath)
    {
        if (!fitsInLocal8bit(item))
        {
            processed << shortPathName(item);
        }
        else
        {
            processed << item;
        }
    }
    args << processed.join(';');
#else
    args << classPath.join(':');
#endif
    args << "org.multimc.EntryPoint";

    qDebug() << args.join(' ');

    QString wrapperCommandStr = instance->getWrapperCommand().trimmed();
    if(!wrapperCommandStr.isEmpty())
    {
        auto wrapperArgs = Commandline::splitArgs(wrapperCommandStr);
        auto wrapperCommand = wrapperArgs.takeFirst();
        auto realWrapperCommand = QStandardPaths::findExecutable(wrapperCommand);
        if (realWrapperCommand.isEmpty())
        {
            QString reason = tr("The wrapper command \"%1\" couldn't be found.").arg(wrapperCommand);
            emit logLine(reason, MessageLevel::Fatal);
            emitFailed(reason);
            return;
        }
        emit logLine("Wrapper command is:\n" + wrapperCommandStr + "\n\n", MessageLevel::MultiMC);
        args.prepend(javaPath);
        m_process.start(wrapperCommand, wrapperArgs + args);
    }
    else
    {
        m_process.start(javaPath, args);
    }
}

void LauncherPartLaunch::on_state(LoggedProcess::State state)
{
    switch(state)
    {
        case LoggedProcess::FailedToStart:
        {
            //: Error message displayed if instace can't start
            QString reason = tr("Could not launch minecraft!");
            emit logLine(reason, MessageLevel::Fatal);
            emitFailed(reason);
            return;
        }
        case LoggedProcess::Aborted:
        case LoggedProcess::Crashed:

        {
            m_parent->setPid(-1);
            emitFailed("Game crashed.");
            return;
        }
        case LoggedProcess::Finished:
        {
            m_parent->setPid(-1);
            // if the exit code wasn't 0, report this as a crash
            auto exitCode = m_process.exitCode();
            if(exitCode != 0)
            {
                emitFailed("Game crashed.");
                return;
            }
            //FIXME: make this work again
            // m_postlaunchprocess.processEnvironment().insert("INST_EXITCODE", QString(exitCode));
            // run post-exit
            emitSucceeded();
            break;
        }
        case LoggedProcess::Running:
            emit logLine(tr("Minecraft process ID: %1\n\n").arg(m_process.processId()), MessageLevel::MultiMC);
            m_parent->setPid(m_process.processId());
            m_parent->instance()->setLastLaunch();
            // send the launch script to the launcher part
            m_process.write(m_launchScript.toUtf8());

            mayProceed = true;
            emit readyForLaunch();
            break;
        default:
            break;
    }
}

void LauncherPartLaunch::setWorkingDirectory(const QString &wd)
{
    m_process.setWorkingDirectory(wd);
}

void LauncherPartLaunch::proceed()
{
    if(mayProceed)
    {
        QString launchString("launch\n");
        m_process.write(launchString.toUtf8());
        mayProceed = false;
    }
}

bool LauncherPartLaunch::abort()
{
    if(mayProceed)
    {
        mayProceed = false;
        QString launchString("abort\n");
        m_process.write(launchString.toUtf8());
    }
    else
    {
        auto state = m_process.state();
        if (state == LoggedProcess::Running || state == LoggedProcess::Starting)
        {
            m_process.kill();
        }
    }
    return true;
}