/***************************************************************************
       FilterPlugin.cpp  -  generic class for filter plugins with setup
                             -------------------
    begin                : Sat Jun 07 2003
    copyright            : (C) 2003 by Thomas Eschenbacher
    email                : Thomas.Eschenbacher@gmx.de
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/


#include <errno.h>
#include <new>
#include <unistd.h>

#include <QApplication>
#include <QDialog>
#include <QStringList>

#include <KLocalizedString>

#include "libkwave/Connect.h"
#include "libkwave/MultiTrackReader.h"
#include "libkwave/MultiTrackWriter.h"
#include "libkwave/PluginManager.h"
#include "libkwave/SampleSink.h"
#include "libkwave/modules/StreamObject.h"
#include "libkwave/undo/UndoTransactionGuard.h"

#include "libgui/FilterPlugin.h"

//***************************************************************************
Kwave::FilterPlugin::FilterPlugin(QObject *parent, const QVariantList &args)
    :Kwave::Plugin(parent, args),
     m_params(), m_listen(false), m_pause(false), m_sink(nullptr)
{
}

//***************************************************************************
Kwave::FilterPlugin::~FilterPlugin()
{
    delete m_sink;
    m_sink = nullptr;
}

//***************************************************************************
QStringList *Kwave::FilterPlugin::setup(QStringList &previous_params)
{
    // try to interpret and use the previous parameters
    if (!interpreteParameters(previous_params))
        m_params = previous_params;

    // create the setup dialog
    Kwave::PluginSetupDialog *setup_dialog = createDialog(parentWidget());
    Q_ASSERT(setup_dialog);
    if (!setup_dialog) return nullptr;

    // connect the signals for the pre-listen handling
    QDialog *dlg = setup_dialog->dialog();
    connect(dlg, SIGNAL(startPreListen()),
            this, SLOT(startPreListen()));
    connect(dlg, SIGNAL(stopPreListen()),
            this, SLOT(stopPreListen()));
    connect(this, SIGNAL(sigDone(Kwave::Plugin*)),
            dlg, SLOT(listenStopped()));

    if (!m_params.isEmpty()) setup_dialog->setParams(m_params);

    QStringList *list = new(std::nothrow) QStringList();
    Q_ASSERT(list);
    if (list && dlg->exec()) {
        // user has pressed "OK"
        *list = setup_dialog->params();
    } else {
        // user pressed "Cancel"
        delete list;
        list = nullptr;
    }

    delete setup_dialog;
    return list;
}

//***************************************************************************
void Kwave::FilterPlugin::run(QStringList params)
{
    Kwave::UndoTransactionGuard *undo_guard = nullptr;
    m_pause = false;

    if (!interpreteParameters(params)) m_params = params;

    sample_index_t first, last;
    QVector<unsigned int> tracks;
    selection(&tracks, &first, &last, true);

    // switch to interactive mode in pre-listen mode
    Kwave::StreamObject::setInteractive(m_listen);

    Kwave::SampleSource *filter =
        createFilter(static_cast<unsigned int>(tracks.count()));
    Q_ASSERT(filter);

    // create all objects
    Kwave::MultiTrackReader source(
        (m_listen) ? Kwave::FullSnapshot : Kwave::SinglePassForward,
        signalManager(), tracks, first, last);
    connect(this, SIGNAL(sigCancel()), &source, SLOT(cancel()),
            Qt::DirectConnection);

    if (m_listen) {
        // pre-listen mode
        Q_ASSERT(m_sink);
    } else {
        // normal mode, with undo
        undo_guard = new(std::nothrow)
            Kwave::UndoTransactionGuard(*this, actionName());
        Q_ASSERT(undo_guard);
        if (!undo_guard) {
            delete filter;
            Kwave::StreamObject::setInteractive(false);
            return;
        }
        m_sink = new(std::nothrow) MultiTrackWriter(signalManager(), tracks,
            Kwave::Overwrite, first, last);
        Q_ASSERT(m_sink);
    }
    if (!filter || !m_sink || m_sink->done()) {
        delete filter;
        delete undo_guard;
        delete m_sink;
        m_sink = nullptr;
        Kwave::StreamObject::setInteractive(false);
        return;
    }

    // set up the progress dialog when in processing (not pre-listen) mode
    if (!m_listen) {
        connect(&source, SIGNAL(progress(qreal)),
                this,    SLOT(updateProgress(qreal)),
                Qt::BlockingQueuedConnection);
    }

    // force initial update of the filter settings
    updateFilter(filter, true);

    // connect them
    Kwave::connect(source,  SIGNAL(output(Kwave::SampleArray)),
                   *filter, SLOT(input(Kwave::SampleArray)));
    Kwave::connect(*filter, SIGNAL(output(Kwave::SampleArray)),
                   *m_sink, SLOT(input(Kwave::SampleArray)));

    // transport the samples
    while (!shouldStop() && (!source.done() || m_listen)) {
        // process one step
        if (m_listen) QThread::yieldCurrentThread();
        source.goOn();
        filter->goOn();

        // watch out for changed parameters when in
        // pre-listen mode
        if (m_listen && paramsChanged()) {
            updateFilter(filter);
        }

        if (m_listen && source.done()) {
            // start the next loop
            source.reset();
            continue;
        }

        // this lets the process wait if the user pressed cancel
        // and the confirm_cancel dialog is active
        while (m_pause && !shouldStop())
            sleep(1);
    }

    // cleanup
    delete filter;
    if (!m_listen) {
        delete m_sink;
        m_sink = nullptr;
    }
    delete undo_guard;

    m_pause  = false;
    m_listen = false;

    Kwave::StreamObject::setInteractive(false);
}

//***************************************************************************
bool Kwave::FilterPlugin::paramsChanged()
{
    return false;
}

//***************************************************************************
void Kwave::FilterPlugin::updateFilter(Kwave::SampleSource * /*filter*/,
                                       bool /*force*/)
{
    /* default implementation, does nothing */
}

//***************************************************************************
void Kwave::FilterPlugin::startPreListen()
{
    Q_ASSERT(!m_sink);
    delete m_sink;
    m_sink = manager().openMultiTrackPlayback(
        static_cast<unsigned int>(selectedTracks().count()));

    if (m_sink) {
        m_listen = true;
        setProgressDialogEnabled(false);
        static QStringList empty_list;
        execute(empty_list);
    }
}

//***************************************************************************
void Kwave::FilterPlugin::stopPreListen()
{
    stop();
    m_listen = false;
    setProgressDialogEnabled(true);
    delete m_sink;
    m_sink = nullptr;
}

//***************************************************************************
QString Kwave::FilterPlugin::progressText()
{
    return i18n("Applying '%1'...", actionName());
}

//***************************************************************************
//***************************************************************************

#include "moc_FilterPlugin.cpp"