/*
 * Copyright 2014-2016 Markus Prasser
 *
 * 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/>.
 */

#include <memory>

#include <QDebug>

#include "receipts_handler.h"
#include "settings.h"

extern std::unique_ptr< lc::Settings > settings;

lc::ReceiptsHandler::ReceiptsHandler( const QString &argZTreeDataTargetPath,
                                      bool argPrintReceiptsForLocalClients,
                                      const QString &argAnonymousReceiptsPlaceholder,
                                      const QString &argLatexHeaderName,
                                      QObject *argParent ) :
    QObject{ argParent },
    anonymousReceiptsPlaceholder{ argAnonymousReceiptsPlaceholder },
    dateString{ QDateTime::currentDateTime().toString( "yyMMdd_hhmm" ) },
    expectedPaymentFileName{ dateString + ".pay" },
    expectedPaymentFilePath{ argZTreeDataTargetPath + "/" + dateString + ".pay" },
    latexHeaderName{ argLatexHeaderName },
    paymentFile{ expectedPaymentFilePath },
    printReceiptsForLocalClients{ argPrintReceiptsForLocalClients },
    timer{ new QTimer{ this } },
    zTreeDataTargetPath{ argZTreeDataTargetPath }
{
    qDebug() << "Expected payment file name is:" << expectedPaymentFilePath;

    // Create a QTimer regularly checking if the payment file was created and print it if so
    connect( timer, &QTimer::timeout,
             this, &ReceiptsHandler::PrintReceipts );
    timer->start( 2000 );
}

lc::ReceiptsHandler::ReceiptsHandler( const QString &argZTreeDataTargetPath,
                                      bool argPrintReceiptsForLocalClients,
                                      const QString &argAnonymousReceiptsPlaceholder,
                                      const QString &argLatexHeaderName,
                                      const QString &argDateString, QObject *argParent ) :
    QObject{ argParent },
    anonymousReceiptsPlaceholder{ argAnonymousReceiptsPlaceholder },
    dateString{ argDateString },
    expectedPaymentFileName{ argDateString + ".pay" },
    expectedPaymentFilePath{ argZTreeDataTargetPath + "/" + argDateString + ".pay" },
    latexHeaderName{ argLatexHeaderName },
    paymentFile{ expectedPaymentFilePath },
    printReceiptsForLocalClients{ argPrintReceiptsForLocalClients },
    zTreeDataTargetPath{ argZTreeDataTargetPath }
{
    qDebug() << "Expected payment file name is:" << expectedPaymentFilePath;

    PrintReceipts();
}

void lc::ReceiptsHandler::PrintReceipts() {
    // If the payment file exists, print it
    if ( paymentFile.exists() ) {
        qDebug() << "The payment file has been created and will be printed";
        if ( timer ) {
            timer->stop();
        }

        CreateReceiptsFromPaymentFile();
    }
}

void lc::ReceiptsHandler::CreateReceiptsFromPaymentFile() {
    // Get the data needed for receipts creation from the payment file
    QVector<QString> *rawParticipantsData = nullptr;
    rawParticipantsData = GetParticipantsDataFromPaymentFile();
    for ( int i = 0; i < rawParticipantsData->size(); i++ ) {
        qDebug() << "Payment file line" << QString::number( i ) << ":\t" << rawParticipantsData->at( i );
    }

    // Extract the data of the participant's whose receipts shall be printed
    /* The tab separated fields in the payment file are:
     * SUBJECT  COMPUTER    INTERESTED  NAME    PROFIT  SIGNATURE
     */
    QVector<paymentEntry_t*> *participants = new QVector<paymentEntry_t*>;
    double overall_payoff = 0.0;
    for ( QVector<QString>::iterator it = rawParticipantsData->begin(); it != rawParticipantsData->end() - 1; ++it ) {
        // Split the lines containing the participants' data into their inidivual parts
        QStringList temp_participant_data = it->split('\t', QString::KeepEmptyParts);
        qDebug() << temp_participant_data.join( " - " );
        if ( !printReceiptsForLocalClients && temp_participant_data.at( 3 ).contains( "local" ) ) {
            qDebug() << "Receipt for local client" << temp_participant_data.at( 1 ) << "will not be printed.";
        }
        else {
            // Create a new struct instance for participant data and fill it
            paymentEntry_t *participant  = new paymentEntry_t;
            participant->computer = temp_participant_data.at(1);
            participant->name = temp_participant_data.at(3);
            participant->payoff = temp_participant_data.at(4).toDouble();
            overall_payoff += participant->payoff;
            participants->append(participant);
        }
    }
    delete rawParticipantsData;
    rawParticipantsData = nullptr;

    // Make receipts overview anonymous if requested (at this stage just names are removed, so that the overview still containts the client names
    if ( !anonymousReceiptsPlaceholder.isEmpty() ) {
        MakeReceiptsAnonymous( participants, false );
    }

    // Load the LaTeX header
    QString *latexText = LoadLatexHeader();
    if ( latexText == nullptr ) {
        for ( auto s : *participants ) {
            delete s;
        }
        delete participants;
        participants = nullptr;
        return;
    }

    // Write the comprehension table
    latexText->append( "\n\\COMPREHENSION{\n" );
    unsigned short int zeile = 0;
    for ( auto s : *participants ) {
        latexText->append( expectedPaymentFileName + " & " + s->computer + " & " + s->name + " & " + QString::number( s->payoff, 'f', 2 ) + " \\EUR\\\\\n" );
        if ( zeile % 2 == 0 ) {
            latexText->append( "\\rowcolor[gray]{0.9}\n" );
        }
        ++zeile;
    }

    // MISSING: Appending show up entries to the overview

    // Make also the clients on the receipts anonymous. This is done as second step, so that the beforehand created overview still contains the clients
    if ( !anonymousReceiptsPlaceholder.isEmpty() ) {
        MakeReceiptsAnonymous( participants, true );
    }

    // Add the LaTeX middle sequence
    latexText->append( "}{" + QString::number( overall_payoff, 'f', 2 ) + "}\n\n%%Einzelquittungen\n" );

    // Write the single receipts
    for ( auto s : *participants ) {
        if ( s->payoff >= 0 ) {
            latexText->append( "\\GAINRECEIPT{" + expectedPaymentFileName + "}{" + s->computer + "}{" + s->name + "}{" + QString::number( s->payoff, 'f', 2 ) + "}\n" );
        }
        else {
            latexText->append( "\\LOSSRECEIPT{" + expectedPaymentFileName + "}{" + s->computer + "}{" + s->name + "}{" + QString::number( s->payoff, 'f', 2 ) + "}\n" );
        }
        delete s;
    }
    delete participants;
    participants = nullptr;

    // Append LaTeX ending
    latexText->append( "\\end{document}" );

    qDebug() << *latexText;

    // Create the tex file
    QFile *texFile = new QFile{ zTreeDataTargetPath + "/" + dateString + ".tex" };
    qDebug() << "Tex file" << texFile->fileName() << "will be created for receipts printing.";
    // Clean up any already existing files
    if ( texFile->exists() ) {
        if ( !texFile->remove() ) {
            QMessageBox messageBox( QMessageBox::Critical, "Tex file removing failed", "There already exists a tex file at '" + texFile->fileName()
                                    + "' which cannot be removed. The creation of the receipts printout may fail.", QMessageBox::Ok );
            messageBox.exec();
        }
    }
    // Create a new file
    if ( !texFile->open( QIODevice::Text | QIODevice::WriteOnly ) ) {
        QMessageBox messageBox( QMessageBox::Critical, "Tex file creation failed", "The creation of the tex file for receipts printing at '" + texFile->fileName()
                                + "' failed. Receipts printing will not work.", QMessageBox::Ok );
        messageBox.exec();
        return;
    }

    // Open a QTextStream to write to the file
    QTextStream out( texFile );

    out << *latexText;
    delete latexText;
    latexText = nullptr;

    receiptsPrinter = new ReceiptsPrinter{ dateString, zTreeDataTargetPath, this };
    receiptsPrinter->start();
    connect( receiptsPrinter, &ReceiptsPrinter::PrintingFinished,
             this, &ReceiptsHandler::DeleteReceiptsPrinterInstance );
    connect( receiptsPrinter, &ReceiptsPrinter::ErrorOccurred,
             this, &ReceiptsHandler::DisplayMessageBox );

    // Clean up
    texFile->close();
    delete texFile;
}

void lc::ReceiptsHandler::DeleteReceiptsPrinterInstance() {
    receiptsPrinter->quit();
    receiptsPrinter->wait();
    receiptsPrinter->deleteLater();
    receiptsPrinter = nullptr;
    qDebug() << "Deleted 'ReceiptsPrinter' instance.";

    emit PrintingFinished();
}

void lc::ReceiptsHandler::DisplayMessageBox( QString *argErrorMessage, QString *argHeading ) {
    QMessageBox messageBox( QMessageBox::Warning, *argHeading, *argErrorMessage, QMessageBox::Ok );
    delete argHeading;
    delete argErrorMessage;
    messageBox.exec();
}

QVector<QString> *lc::ReceiptsHandler::GetParticipantsDataFromPaymentFile() {
    // Create the vector to store the single lines of the file
    QVector<QString> *participantsData = new QVector<QString>;

    // Open the payment file for reading and create a QTextStream
    paymentFile.open( QIODevice::ReadOnly | QIODevice::Text );
    QTextStream in( &paymentFile );
    in.setCodec( "ISO 8859-1" );

    // Read the file line by line and store them in the vector
    while ( true ) {
        QString line = in.readLine();
        if ( line.isNull() ) {
            break;
        }
        participantsData->append( line );
    }

    // Remove the first line, since it is not needed
    participantsData->erase( participantsData->begin() );

    // Close the file afterwards
    paymentFile.close();

    return participantsData;
}

QString *lc::ReceiptsHandler::LoadLatexHeader() {
    // Prepare all facilities to read the latex header file
    QFile latexHeaderFile( settings->lcDataDir + "/" + latexHeaderName + "_header.tex" );
    if ( !latexHeaderFile.open( QIODevice::ReadOnly | QIODevice::Text ) ) {
        QMessageBox messageBox{ QMessageBox::Critical, tr( "LaTeX header could not be loaded" ),
                                tr( "The LaTeX header at '%1/%2_header.tex' could not be loaded. Receipts printing will not work." )
                                .arg( settings->lcDataDir ).arg( latexHeaderName ), QMessageBox::Ok };
        messageBox.exec();
        return nullptr;
    }
    QTextStream in( &latexHeaderFile );

    QString *header = nullptr;
    header = new QString( in.readAll() );

    latexHeaderFile.close();

    return header;
}

void lc::ReceiptsHandler::MakeReceiptsAnonymous( QVector<paymentEntry_t*> *argDataVector, bool argAlsoAnonymizeClients ) {
    if ( !argAlsoAnonymizeClients ) {
        qDebug() << "Names are made anonymous";
        for ( QVector< paymentEntry_t* >::iterator it = argDataVector->begin(); it != argDataVector->end(); ++it ) {
            ( *it )->name = anonymousReceiptsPlaceholder;
        }
    }
    else {
       qDebug() << "Clients and names are made anonymous";
       for ( QVector< paymentEntry_t* >::iterator it = argDataVector->begin(); it != argDataVector->end(); ++it ) {
           ( *it )->name = anonymousReceiptsPlaceholder;
           ( *it )->computer = "\\hspace{1cm}";
       }
    }
}