/*
 * Copyright (C) 2020-2022 Roy Qu (royqh1979@gmail.com)
 *
 * 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 3 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, see <https://www.gnu.org/licenses/>.
 */
#include "ojproblemcasesrunner.h"
#include "../utils.h"
#include "../settings.h"
#include "../systemconsts.h"
#include "../widgets/ojproblemsetmodel.h"
#include <QElapsedTimer>
#include <QProcess>


OJProblemCasesRunner::OJProblemCasesRunner(const QString& filename, const QString& arguments, const QString& workDir,
                                           const QVector<POJProblemCase>& problemCases, QObject *parent):
    Runner(filename,arguments,workDir,parent),
    mExecTimeout(-1)
{
    mProblemCases = problemCases;
    mBufferSize = 8192;
    mOutputRefreshTime = 1000;
    setWaitForFinishTime(100);
}

OJProblemCasesRunner::OJProblemCasesRunner(const QString& filename, const QString& arguments, const QString& workDir,
                                           POJProblemCase problemCase, QObject *parent):
    Runner(filename,arguments,workDir,parent),
    mExecTimeout(-1)
{
    mProblemCases.append(problemCase);
    mBufferSize = 8192;
    mOutputRefreshTime = 1000;
    setWaitForFinishTime(100);
}

void OJProblemCasesRunner::runCase(int index,POJProblemCase problemCase)
{
    emit caseStarted(problemCase->getId(),index, mProblemCases.count());
    auto action = finally([this,&index, &problemCase]{
        emit caseFinished(problemCase->getId(), index, mProblemCases.count());
    });
    QProcess process;
    bool errorOccurred = false;
    QByteArray readed;
    QByteArray buffer;
    QByteArray output;
    int noOutputTime = 0;
    QElapsedTimer elapsedTimer;
    bool execTimeouted = false;
    process.setProgram(mFilename);
    process.setArguments(splitProcessCommand(mArguments));
    process.setWorkingDirectory(mWorkDir);
    QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
    QString path = env.value("PATH");
    QStringList pathAdded;
    bool writeChannelClosed = false;
    if (pSettings->compilerSets().defaultSet()) {
        foreach(const QString& dir, pSettings->compilerSets().defaultSet()->binDirs()) {
            pathAdded.append(dir);
        }
    }
    pathAdded.append(pSettings->dirs().appDir());
    if (!path.isEmpty()) {
        path+= PATH_SEPARATOR + pathAdded.join(PATH_SEPARATOR);
    } else {
        path = pathAdded.join(PATH_SEPARATOR);
    }
    env.insert("PATH",path);
    process.setProcessEnvironment(env);
    process.setProcessChannelMode(QProcess::MergedChannels);
    process.connect(
                &process, &QProcess::errorOccurred,
                [&](){
        errorOccurred= true;
    });
    problemCase->output.clear();
    process.start();
    process.waitForStarted(5000);
    if (process.state()==QProcess::Running) {
        if (fileExists(problemCase->inputFileName))
            process.write(readFileToByteArray(problemCase->inputFileName));
        else
            process.write(problemCase->input.toUtf8());
        process.waitForFinished(0);
    }

    elapsedTimer.start();
    while (true) {
        if (process.bytesToWrite()==0 && !writeChannelClosed) {
            writeChannelClosed = true;
            process.closeWriteChannel();
        }
        process.waitForFinished(mWaitForFinishTime);
        if (process.state()!=QProcess::Running) {
            break;
        }
        if (mExecTimeout>0) {
            int msec = elapsedTimer.elapsed();
            if (msec>mExecTimeout) {
                execTimeouted=true;
            }
        }
        if (mStop || execTimeouted) {
            process.terminate();
            process.kill();
            break;
        }
        if (errorOccurred)
            break;
        readed = process.read(mBufferSize);
        buffer += readed;
        if (buffer.length()>=mBufferSize || noOutputTime > mOutputRefreshTime) {
            if (!buffer.isEmpty()) {
                emit newOutputGetted(problemCase->getId(),QString::fromLocal8Bit(buffer));
                output.append(buffer);
                buffer.clear();
            }
            noOutputTime = 0;
        } else {
            noOutputTime += mWaitForFinishTime;
        }
    }
    problemCase->runningTime=elapsedTimer.elapsed();
    if (execTimeouted) {
        problemCase->output = tr("Case Timeout");
        emit resetOutput(problemCase->getId(), problemCase->output);
    } else {
        if (process.state() == QProcess::ProcessState::NotRunning)
            buffer += process.readAll();
        emit newOutputGetted(problemCase->getId(),QString::fromLocal8Bit(buffer));
        output.append(buffer);
        problemCase->output = QString::fromLocal8Bit(output);
        if (errorOccurred) {
            //qDebug()<<"process error:"<<process.error();
            switch (process.error()) {
            case QProcess::FailedToStart:
                emit runErrorOccurred(tr("The runner process '%1' failed to start.").arg(mFilename));
                break;
    //        case QProcess::Crashed:
    //            if (!mStop)
    //                emit runErrorOccurred(tr("The runner process crashed after starting successfully."));
    //            break;
            case QProcess::Timedout:
                emit runErrorOccurred(tr("The last waitFor...() function timed out."));
                break;
            case QProcess::WriteError:
                emit runErrorOccurred(tr("An error occurred when attempting to write to the runner process."));
                break;
            case QProcess::ReadError:
                emit runErrorOccurred(tr("An error occurred when attempting to read from the runner process."));
                break;
            default:
                break;
            }
        }
    }
}

void OJProblemCasesRunner::run()
{
    emit started();
    auto action = finally([this]{
        emit terminated();
    });
    for (int i=0; i < mProblemCases.size(); i++) {
        if (mStop)
            break;
        POJProblemCase problemCase = mProblemCases[i];
        runCase(i,problemCase);
    }
}

int OJProblemCasesRunner::execTimeout() const
{
    return mExecTimeout;
}

void OJProblemCasesRunner::setExecTimeout(int newExecTimeout)
{
    mExecTimeout = newExecTimeout;
}

int OJProblemCasesRunner::waitForFinishTime() const
{
    return mWaitForFinishTime;
}

void OJProblemCasesRunner::setWaitForFinishTime(int newWaitForFinishTime)
{
    mWaitForFinishTime = newWaitForFinishTime;
}

int OJProblemCasesRunner::outputRefreshTime() const
{
    return mOutputRefreshTime;
}

void OJProblemCasesRunner::setOutputRefreshTime(int newOutputRefreshTime)
{
    mOutputRefreshTime = newOutputRefreshTime;
}

int OJProblemCasesRunner::bufferSize() const
{
    return mBufferSize;
}

void OJProblemCasesRunner::setBufferSize(int newBufferSize)
{
    mBufferSize = newBufferSize;
}