/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */

/*
    Rosegarden
    A MIDI and audio sequencer and musical notation editor.
    Copyright 2000-2022 the Rosegarden development team.
 
    Other copyrights also apply to some parts of this work.  Please
    see the AUTHORS file and individual file headers for details.
 
    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.  See the file
    COPYING included with this distribution for more m_information.
*/

#include "LilyPondProcessor.h"

#include "gui/general/IconLoader.h"
#include "gui/widgets/ProgressBar.h"
#include "misc/ConfigGroups.h"

#include <QDialog>
#include <QProcess>
#include <QGridLayout>
#include <QPushButton>
#include <QSettings>
#include <QLabel>
#include <QMessageBox>
#include <QDir>
#include <QTextCodec>

#include <iostream>

namespace Rosegarden
{

LilyPondProcessor::LilyPondProcessor(QWidget *parent, int mode, QString filename) :
        QDialog(parent),
        m_mode(mode)
{
    // We have to split the combined filename (eg. "/tmp/rosegarden_tmp_T73123.ly"
    // into a separate filename and directory component, to hack around a
    // critical bug I couldn't resolve any other way.
    int pos = filename.lastIndexOf("/");
    m_filename = filename.mid(pos + 1, (filename.size() - pos - 1));
    m_dir = QDir::tempPath(); // OK, we'll just be lazy and not parse it back out of the string

    // (I'm not sure why RG_DEBUG didn't work from in here.  Having to use
    // iostream is mildly irritating, as QStrings have to be converted, but
    // whatever, I'll figure that out later, or just leave well enough alone)
    std::cerr << "LilyPondProcessor::LilyPondProcessor():  mode: " << mode << " m_filename: " << m_filename.toStdString() << std::endl;

    this->setModal(false);

    setWindowIcon(IconLoader::loadPixmap("window-lilypond"));

    QGridLayout *layout = new QGridLayout;
    this->setLayout(layout);

    QLabel *icon = new QLabel(this);
    icon->setPixmap(IconLoader::loadPixmap("rosegarden-lilypond"));
    layout->addWidget(icon, 0, 0);

    QString modeStr;
    switch (mode) {
        case LilyPondProcessor::Preview: modeStr = tr("Preview"); break;
        case LilyPondProcessor::Print:   modeStr = tr("Print");   break;
    }
    this->setWindowTitle(tr("Rosegarden - %1 with LilyPond...").arg(modeStr));

    m_info = new QLabel(this);
    m_info->setWordWrap(true);
    layout->addWidget(m_info, 0, 1);

    m_progress = new ProgressBar(this);
    layout->addWidget(m_progress, 1, 1);

    QPushButton *ok = new QPushButton(tr("Cancel"), this);
    connect(ok, &QAbstractButton::clicked, this, &QDialog::reject);
    layout->addWidget(ok, 3, 1); 

   
    // Just run convert.ly without all the logic to figure out if it's needed or
    // not.  This is harmless, and adds little extra processing time if the
    // conversion isn't required.  This is the first link in a spaghetti bowl
    // chain of slots.  We either have to run all of this in a thread apart from
    // the main GUI thread or use this spaghetti bowl chaining technique in
    // order to avoid freezing the entire application while chewing on large
    // processing jobs, as we really must wait for step A to finish before
    // continuing to step B.  I have no experience with threads, so the
    // spaghetti option is the most expedient, if less educational choice.
    runConvertLy();
}

void
LilyPondProcessor::puke(const QString& error, const QString &details)
{
    m_progress->setMaximum(100);
    m_progress->hide();

    m_info->setText(tr("Fatal error.  Processing aborted."));
    QMessageBox messageBox(this);
    messageBox.setIcon(QMessageBox::Critical);
    messageBox.setWindowTitle(tr("Rosegarden - Fatal processing error!"));
    messageBox.setText(error);
    messageBox.setDetailedText(details);
    messageBox.exec();

    // abort processing after a fatal error, so calls to puke() abort the whole
    // process in its tracks
    reject();

    // Well, that was the theory.  In practice it apparently isn't so easy to do
    // the bash equivalent of a spontaneous "exit 1" inside a QDialog.  Hrm.
}

void
LilyPondProcessor::runConvertLy()
{
    std::cerr << "LilyPondProcessor::runConvertLy()" << std::endl;

    m_info->setText(tr("Running <b>convert-ly</b>..."));
    m_process = new QProcess;
    m_process->setWorkingDirectory(m_dir);
    m_process->start("convert-ly", QStringList() << "-e" << m_filename);
    connect(m_process, SIGNAL(finished(int, QProcess::ExitStatus)),
            this, SLOT(runLilyPond(int, QProcess::ExitStatus)));

    // wait up to 30 seconds for process to start
    if (m_process->waitForStarted()) {
        m_info->setText(tr("<b>convert-ly</b> started..."));
    } else {
        puke(tr("<qt><p>Could not run <b>convert-ly</b>!</p><p>Please install LilyPond and ensure that the \"convert-ly\" and \"lilypond\" commands are available on your path.  If you perform a <b>Run Command</b> (typically <b>Alt+F2</b>) and type \"convert-ly\" into the box, you should not get a \"command not found\" error.  If you can do that without getting an error, but still see this error message, please consult <a style=\"color:gold\" href=\"mailto:rosegarden-user@lists.sourceforge.net\">rosegarden-user@lists.sourceforge.net</a> for additional help.</p><p>Processing terminated due to fatal errors.</p></qt>"));
    }

    m_progress->setValue(25);
}

void
LilyPondProcessor::runLilyPond(int exitCode, QProcess::ExitStatus)
{
    std::cerr << "LilyPondProcessor::runLilyPond()" << std::endl;

    if (exitCode == 0) {
        m_info->setText(tr("<b>convert-ly</b> finished..."));
        delete m_process;
    } else {
        puke(tr("<qt><p>Ran <b>convert-ly</b> successfully, but it terminated with errors.</p><p>Processing terminated due to fatal errors.</p></qt>"));
    }

    m_progress->setValue(50);

    m_process = new QProcess;
    m_process->setWorkingDirectory(m_dir);
    m_info->setText(tr("Running <b>lilypond</b>..."));
    m_process->start("lilypond", QStringList() << "--pdf" << m_filename);
    connect(m_process, SIGNAL(finished(int, QProcess::ExitStatus)),
            this, SLOT(runFinalStage(int, QProcess::ExitStatus)));
            

    if (m_process->waitForStarted()) {
        m_info->setText(tr("<b>lilypond</b> started..."));
    } else {
        puke(tr("<qt><p>Could not run <b>lilypond</b>!</p><p>Please install LilyPond and ensure that the \"convert-ly\" and \"lilypond\" commands are available on your path.  If you perform a <b>Run Command</b> (typically <b>Alt+F2</b>) and type \"lilypond\" into the box, you should not get a \"command not found\" error.  If you can do that without getting an error, but still see this error message, please consult <a style=\"color:gold\" href=\"mailto:rosegarden-user@lists.sourceforge.net\">rosegarden-user@lists.sourceforge.net</a> for additional help.</p><p>Processing terminated due to fatal errors.</p></qt>"));
    }

    // go into Knight Rider mode when chewing on LilyPond, because it can take
    // an eternity, but I don't really want to re-create all the text stream
    // monitoring and guessing code that's easy to do in a script and hell to do
    // in real code
    m_progress->setMaximum(0);
}

void
LilyPondProcessor::runFinalStage(int exitCode, QProcess::ExitStatus)
{
    std::cerr << "LilyPondProcessor::runFinalStage()" << std::endl;

    if (exitCode == 0) {
        m_info->setText(tr("<b>lilypond</b> finished..."));
        delete m_process;
    } else {

        // read preferences from last export from QSettings to offer clues what
        // failed
        QSettings settings;
        settings.beginGroup(LilyPondExportConfigGroup);
        bool exportedBeams = settings.value("lilyexportbeamings", false).toBool();
        bool exportedBrackets = settings.value("lilyexportstaffbrackets", false).toBool();
        settings.endGroup();

        std::cerr << "  finalStage: exportedBeams == " << (exportedBeams ? "true" : "false") << std::endl
                  << " exportedBrackets == " << (exportedBrackets ? "true" : "false") << std::endl;

        QString vomitus = "<html>";
        vomitus += tr("<p>Ran <b>lilypond</b> successfully, but it terminated with errors.</p>");

        if (exportedBeams) {
            vomitus += tr("<p>You opted to export Rosegarden's beaming, and LilyPond could not process the file.  It is likely that you performed certain actions in the course of editing your file that resulted in hidden beaming properties being attached to events where they did not belong, and this probably caused LilyPond to fail.  The recommended solution is to either leave beaming to LilyPond (whose automatic beaming is far better than Rosegarden's) and un-check this option, or to un-beam everything and then re-beam it all manually inside Rosgarden.  Leaving the beaming up to LilyPond is probaby the best solution.</p>");
        }

        if (exportedBrackets) {
            vomitus += tr("<p>You opted to export staff group brackets, and LilyPond could not process the file.  Unfortunately, this useful feature can be very fragile.  Please go back and ensure that all the brackets you've selected make logical sense, paying particular attention to nesting.  Also, please check that if you are working with a subset of the total number of tracks, the brackets on that subset make sense together when taken out of the context of the whole.  If you have any doubts, please try turning off the export of staff group brackets to see whether LilyPond can then successfully render the result.</p>");
        }

        vomitus += tr("<p>Processing terminated due to fatal errors.</p>");

        vomitus += "</html>";

        QTextCodec *codec = QTextCodec::codecForLocale();
        puke(vomitus, codec->toUnicode(m_process->readAllStandardError()));

        // puke doesn't actually work, so we have to return in order to avoid
        // further processing
        return;
    }

    QString pdfName = m_filename.replace(".ly", ".pdf");

    // retrieve user preferences from QSettings
    QSettings settings;
    settings.beginGroup(ExternalApplicationsConfigGroup);
    int pdfViewerIndex = settings.value("pdfviewer", 0).toUInt();
    int filePrinterIndex = settings.value("fileprinter", 0).toUInt();
    settings.endGroup();

    QString pdfViewer, filePrinter;

    // assumes the PDF viewer is available in the PATH; no provision is made for
    // the user to specify the location of any of these explicitly, and I'd like
    // to avoid having to go to that length if at all possible, in order to
    // reduce complexity both in code and on the user side of the configuration
    // page (I guess arguably the configuration page shouldn't exist, and we
    // should just try things sequentially until something works, but it gets
    // into real headaches trying to guess what someone would prefer based on
    // what desktop they're running, and anyway specifying explicitly avoids the
    // reason why my copy of acroread is normally chmod -x so the script
    // ancestor of this class wouldn't pick it up against my wishes)
    switch (pdfViewerIndex) {
        case 0: pdfViewer = "okular";   break;
        case 1: pdfViewer = "evince";   break;
        case 2: pdfViewer = "acroread"; break;
        case 3: pdfViewer = "mupdf";    break;
        case 4: pdfViewer = "epdfview"; break;
        case 5: pdfViewer = "xdg-open"; break;
        default: pdfViewer = "xdg-open";
    }

    switch (filePrinterIndex) {
        case 0: filePrinter = "gtklp";    break;
        case 1: filePrinter = "lp";      break;
        case 2: filePrinter = "lpr";       break;
        case 3: filePrinter = "hp-print"; break;
        default: filePrinter = "lpr";     break;
    }

    // So why didn't I just manipulate finalProcessor in the first place?
    // Because I just thought of that, but don't feel like refactoring all of
    // this yet again.  Oh well.
    QString finalProcessor;

    m_process = new QProcess;

    switch (m_mode) {
        case LilyPondProcessor::Print:
            m_info->setText(tr("Printing %1...").arg(pdfName));
            finalProcessor = filePrinter;
            break;

        // just default to preview (I always use preview anyway, as I never
        // trust the results for a direct print without previewing them first,
        // and in fact the direct print option seems somewhat dubious to me)
        case LilyPondProcessor::Preview:
        default:
            m_info->setText(tr("Previewing %1...").arg(pdfName));
            finalProcessor = pdfViewer;
    }

    m_process->setWorkingDirectory(m_dir);
    m_process->start(finalProcessor, QStringList() << pdfName);
    if (m_process->waitForStarted()) {
        QString t = QString(tr("<b>%1</b> started...").arg(finalProcessor));
    } else {
        QString t = QString(tr("<qt><p>LilyPond processed the file successfully, but <b>%1</b> did not run!</p><p>Please configure a valid %2 under <b>Edit -> Preferences -> General -> External Applications</b> and try again.</p><p>Processing terminated due to fatal errors.</p></qt>")).arg(finalProcessor).arg(
                (m_mode == LilyPondProcessor::Print ? tr("file printer") : tr("PDF viewer")));
        puke(t);
    }

    m_progress->setMaximum(100);
    m_progress->setValue(100);

    accept();
}

}

