/*
 * Copyright 2014-2018 Markus Prasser, Tobias Weiss
 *
 * This file is part of Labcontrol.
 *
 *  Labcontrol 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.
 *
 *  Labcontrol 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 Labcontrol.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef RECEIPTSPRINTER_H
#define RECEIPTSPRINTER_H

#include <QMessageBox>
#include <QProcess>
#include <QThread>

namespace lc {

class Settings;

//! A class for receipts creation.
/*!
  This class is used to do the actual printing of the receipts in an own thread.
*/
class ReceiptsPrinter : public QThread
{
    Q_OBJECT

    void run() override
    {
        // Compile the TeX file to dvi
        QStringList arguments;
        arguments << "-interaction" << "batchmode" << QString{dateString + ".tex"};

        QProcess *process = nullptr;
        process = new QProcess{};
        const QProcessEnvironment env{QProcessEnvironment::systemEnvironment()};
        process->setProcessEnvironment(env);
        process->setWorkingDirectory(workpath);
        process->start(latexCmd, arguments);
        if (!process->waitForFinished(processTimeOut)) {
            QMessageBox message_box{QMessageBox::Warning, "dvi creation failed",
                                    "The creation of the receipts dvi timed out"
                                    " after 30 seconds. Automatic receipts creation will not work.",
                                    QMessageBox::Ok};
            message_box.exec();
            delete process;
            process = nullptr;
            return;
        }
        delete process;
        process = nullptr;

        // Convert the dvi file to postscript
        arguments = QStringList{};
        arguments << "-q*" << "-o" << QString{dateString + ".ps"} << QString{dateString + ".dvi"};

        process = new QProcess{};
        process->setProcessEnvironment(env);
        process->setWorkingDirectory(workpath);
        process->start(dvipsCmd, arguments);
        if (!process->waitForFinished(processTimeOut)) {
            emit ErrorOccurred(new QString{"The conversion of the receipts dvi to postscript timed out after 30 seconds. Automatic receipts creation will not work."},
                               new QString{"dvi to postscript conversion failed"});
            delete process;
            process = nullptr;
            return;
        }
        delete process;
        process = nullptr;

        // Print the postscript file
        if (!lprCmd.isEmpty()) {
            arguments = QStringList{};
            arguments << QString{workpath + "/" + dateString + ".ps"};

            process = new QProcess{};
            process->setProcessEnvironment(env);
            process->setWorkingDirectory(workpath);
            process->start(lprCmd, arguments);
            if ( !process->waitForFinished( processTimeOut ) ) {
                emit ErrorOccurred(new QString{"The receipts postscript file was successfully created but could not be printed."},
                                   new QString{"Printing failed"});
            }
            delete process;
            process = nullptr;
        }

        // Convert the postscript file to pdf
        if (!ps2pdfCmd.isEmpty()) {
            arguments = QStringList{};
            arguments << QString{workpath + "/" + dateString + ".ps"} << QString{workpath + "/" + dateString + ".pdf"};

            process = new QProcess{};
            process->setProcessEnvironment(env);
            process->setWorkingDirectory(workpath);
            process->start(ps2pdfCmd, arguments);
            if (!process->waitForFinished(processTimeOut)) {
                emit ErrorOccurred(new QString{"The receipts were successfully printed but the creation of the PDF file failed."},
                                   new QString{"PDF creation failed"});
            }
            delete process;
            process = nullptr;

            // Show the postscript file if the conversion succeeded
            if (!postscriptViewer.isEmpty()) {
                arguments = QStringList{};
                arguments << QString{workpath + "/" + dateString + ".ps"};

                process = new QProcess{};
                process->setProcessEnvironment(env);
                process->setWorkingDirectory(workpath);
                process->startDetached(postscriptViewer, arguments);
                delete process;
                process = nullptr;
            }
        }

        // Clean up the zTree working path
        if (!rmCmd.isEmpty()) {
            arguments = QStringList{};
            arguments << QString{workpath + "/" + dateString + ".aux"}
                      << QString{workpath + "/" + dateString + ".dvi"}
                      << QString{workpath + "/" + dateString + ".log"}
                      << QString{workpath + "/" + dateString + ".tex"};

            process = new QProcess{};
            process->setProcessEnvironment(env);
            process->setWorkingDirectory(workpath);
            process->start( rmCmd, arguments);
            if (!process->waitForFinished(processTimeOut)) {
                emit ErrorOccurred(new
                                   QString("The cleanup of the temporary files for receipts creation timed out. Some spare files may be left in your zTree working directory."),
                                   new QString("Cleanup failed"));
            }
            delete process;
            process = nullptr;
        }

        emit PrintingFinished();
    }
public:
    explicit ReceiptsPrinter(const QString &argDateString,
                             const Settings *const argSettings,
                             const QString &argWorkpath,
                             QObject *argParent = nullptr);

signals:
    void ErrorOccurred(QString *error_message, QString *heading);
    void PrintingFinished();

private:
    const QString dateString;               //! The date string contained in the file paths
    const QString dvipsCmd;
    const QString latexCmd;
    const QString lprCmd;
    const QString postscriptViewer;
    const int processTimeOut =
        15000;                           //! The maximum time which will be granted to a started process
    const QString ps2pdfCmd;
    const QString rmCmd;
    const QString vncViewer;
    const QString workpath;                 //!< The path were zTree was ordered to store all its data
};

} // namespace lc

#endif // RECEIPTSPRINTER_H