/*************************************************************************
        WavDecoder.cpp  -  decoder for wav data
                             -------------------
    begin                : Sun Mar 10 2002
    copyright            : (C) 2002 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 "config.h"
#include <stdlib.h>
#include <new>

#include <audiofile.h>

#include <QIODevice>
#include <QList>
#include <QVector>
#include <QtEndian>
#include <QtGlobal>

#include <QApplication>
#include <QProgressDialog>

#include <KLocalizedString>

#include "libkwave/Compression.h"
#include "libkwave/ConfirmCancelProxy.h"
#include "libkwave/Label.h"
#include "libkwave/LabelList.h"
#include "libkwave/MessageBox.h"
#include "libkwave/MetaData.h"
#include "libkwave/MetaDataList.h"
#include "libkwave/MultiWriter.h"
#include "libkwave/Sample.h"
#include "libkwave/SampleFormat.h"
#include "libkwave/String.h"
#include "libkwave/Utils.h"
#include "libkwave/VirtualAudioFile.h"
#include "libkwave/Writer.h"

#include "RIFFChunk.h"
#include "RIFFParser.h"
#include "RecoveryBuffer.h"
#include "RecoveryMapping.h"
#include "RecoverySource.h"
#include "RepairVirtualAudioFile.h"
#include "WavDecoder.h"
#include "WavFileFormat.h"
#include "WavFormatMap.h"

#define CHECK(cond) Q_ASSERT(cond); if (!(cond)) { src.close(); return false; }

//***************************************************************************
Kwave::WavDecoder::WavDecoder()
    :Kwave::Decoder(),
     m_source(nullptr),
     m_src_adapter(nullptr),
     m_known_chunks(),
     m_property_map()
{
    REGISTER_MIME_TYPES
    REGISTER_COMPRESSION_TYPES

    // native WAVE chunk names
    m_known_chunks.append(_("cue ")); /* Markers */
    m_known_chunks.append(_("data")); /* Sound Data */
    m_known_chunks.append(_("fact")); /* Fact (length in samples) */
    m_known_chunks.append(_("fmt ")); /* Format */
    m_known_chunks.append(_("inst")); /* Instrument */
    m_known_chunks.append(_("labl")); /* label */
    m_known_chunks.append(_("ltxt")); /* labeled text */
    m_known_chunks.append(_("note")); /* note chunk */
    m_known_chunks.append(_("plst")); /* Play List */
    m_known_chunks.append(_("smpl")); /* Sampler */

    // add all sub-chunks of the LIST chunk (properties)
    foreach (const QByteArray &name, m_property_map.chunks())
        m_known_chunks.append(QLatin1String(name));

    // some chunks known from AIFF format
    m_known_chunks.append(_("FVER"));
    m_known_chunks.append(_("COMM"));
    m_known_chunks.append(_("wave"));
    m_known_chunks.append(_("SSND"));

    // chunks of .lbm image files, IFF format
    m_known_chunks.append(_("BMHD"));
    m_known_chunks.append(_("CMAP"));
    m_known_chunks.append(_("BODY"));
}

//***************************************************************************
Kwave::WavDecoder::~WavDecoder()
{
    if (m_source) close();
    delete m_src_adapter;
    m_src_adapter = nullptr;
}

//***************************************************************************
Kwave::Decoder *Kwave::WavDecoder::instance()
{
    return new(std::nothrow) Kwave::WavDecoder();
}

//***************************************************************************
bool Kwave::WavDecoder::open(QWidget *widget, QIODevice &src)
{
    Kwave::FileInfo info;
    Kwave::LabelList labels;
    metaData().clear();

    Q_ASSERT(!m_source);
    bool need_repair = false;
    if (m_source) qWarning("WavDecoder::open(), already open !");

    // try to open the source
    if (!src.open(QIODevice::ReadOnly)) {
        qWarning("failed to open source !");
        return false;
    }

    QStringList main_chunks;
    main_chunks.append(_("RIFF")); /* RIFF, little-endian */
    main_chunks.append(_("RIFX")); /* RIFF, big-endian */
    main_chunks.append(_("FORM")); /* used in AIFF, BE or IFF/.lbm */
    main_chunks.append(_("LIST")); /* additional information */
    main_chunks.append(_("adtl")); /* Associated Data */

    Kwave::RIFFParser parser(src, main_chunks, m_known_chunks);

    // prepare a progress dialog
    QProgressDialog progress(widget);
    progress.setWindowTitle(i18n("Auto Repair"));
    progress.setModal(true);
    progress.setMinimumDuration(0);
    progress.setMaximum(100);
    progress.setAutoClose(true);
    progress.setValue(0);
    progress.setLabelText(i18n("Reading..."));
    connect(&parser,   SIGNAL(progress(int)),
            &progress, SLOT(setValue(int)));
    connect(&parser,   SIGNAL(action(QString)),
            &progress, SLOT(setLabelText(QString)));
    Kwave::ConfirmCancelProxy confirm_cancel(widget,
                       &progress, SIGNAL(canceled()),
                       &parser,   SLOT(cancel()));

    // parse, including endianness detection
    parser.parse();
    progress.reset();
    if (progress.wasCanceled()) return false;

//     qDebug("--- RIFF file structure after first pass ---");
//     parser.dumpStructure();

    // check if there is a RIFF chunk at all...
    Kwave::RIFFChunk *riff_chunk = parser.findChunk("/RIFF:WAVE");
    Kwave::RIFFChunk *fact_chunk = parser.findChunk("/RIFF:WAVE/fact");
    Kwave::RIFFChunk *fmt_chunk  = parser.findChunk("/RIFF:WAVE/fmt ");
    Kwave::RIFFChunk *data_chunk = parser.findChunk("/RIFF:WAVE/data");

    if (!riff_chunk || !fmt_chunk || !data_chunk || !parser.isSane()) {
        if (Kwave::MessageBox::warningContinueCancel(widget,
            i18n("The file has been structurally damaged or "
                 "it is no WAV file.\n"
                 "Should Kwave try to repair it?"),
            i18n("Kwave Auto Repair"),
            i18n("&Repair")) != KMessageBox::Continue)
        {
            // user didn't let us try :-(
            return false;
        }

        need_repair = true;
    }

    // collect all missing chunks
    if (!riff_chunk) riff_chunk = parser.findMissingChunk("RIFF:WAVE");
    if (progress.wasCanceled()) return false;

    if (!fmt_chunk) {
        parser.findMissingChunk("fmt ");
        fmt_chunk = parser.findChunk("/RIFF:WAVE/fmt ");
        if (progress.wasCanceled()) return false;
        if (!fmt_chunk)  fmt_chunk  = parser.findChunk("fmt ");
        need_repair = true;
    }

    if (!data_chunk) {
        parser.findMissingChunk("data");
        data_chunk = parser.findChunk("/RIFF:WAVE/data");
        if (progress.wasCanceled()) return false;
        if (!data_chunk) data_chunk = parser.findChunk("data");
        need_repair = true;
    }

    // not everything found -> need heavy repair actions !
    if (!fmt_chunk || !data_chunk || need_repair) {
        qDebug("doing heavy repair actions...");
        parser.dumpStructure();
        parser.repair();
        parser.dumpStructure();
        if (progress.wasCanceled()) return false;

        if (!fmt_chunk)  fmt_chunk  = parser.findChunk("/RIFF:WAVE/fmt ");
        if (!fmt_chunk)  fmt_chunk  = parser.findChunk("/RIFF/fmt ");
        if (!fmt_chunk)  fmt_chunk  = parser.findChunk("fmt ");
        if (!data_chunk) data_chunk = parser.findChunk("/RIFF:WAVE/data");
        if (!data_chunk) data_chunk = parser.findChunk("/RIFF/data");
        if (!data_chunk) data_chunk = parser.findChunk("data");
        need_repair = true;
    }

    quint32 fmt_offset = 0;
    if (fmt_chunk) fmt_offset = fmt_chunk->dataStart();
//     qDebug("fmt chunk starts at 0x%08X", fmt_offset);

//     quint32 data_offset = 0;
    quint32 data_size = 0;
    if (data_chunk) {
//      data_offset = data_chunk->dataStart();
        data_size   = data_chunk->physLength();
//      qDebug("data chunk at 0x%08X (%u byte)", data_offset, data_size);
    }

    if (!data_size) {
        // hide progress bar, finally
        progress.hide();
        qApp->processEvents();

        // show final error message
        Kwave::MessageBox::sorry(widget,
            i18n("The opened file is no WAV file or it is damaged:\n"
            "There is not enough valid sound data.\n\n"
            "It makes no sense to continue now."));
        return false;
    }

    // WORKAROUND: if there is a fact chunk, it must not contain zero
    //             for the moment the only workaround known is to open
    //             such broken files in repair mode
    if (fact_chunk) {
        qint64 offset = fact_chunk->dataStart();
        union {
            quint32 len;
            char    bytes[4];
        } fact;
        fact.len = 0;
        src.seek(offset);
        src.read(&(fact.bytes[0]), 4);
        if ((fact.len == 0x00000000) || (fact.len == 0xFFFFFFFF)) {
            qWarning("WARNING: invalid 'fact' chunk content: 0x%08X "
                     "-> silent repair mode", fact.len);
            need_repair = true;
        }
    }

    // final check for structural integrity:
    // we should have exactly one RIFF, fmt and data chunk !
    if ((parser.chunkCount("fmt ") != 1) ||
        (parser.chunkCount("data") != 1))
    {
        // hide progress bar, temporarily
        progress.hide();
        qApp->processEvents();

        if (Kwave::MessageBox::warningContinueCancel(widget,
            i18n("The WAV file seems to be damaged:\n"
                 "Some chunks are duplicate or missing.\n\n"
                 "Kwave will only use the first ones and ignore\n"
                 "the rest. This might lead to loss of data."),
            i18n("Kwave Auto Repair")
            ) != KMessageBox::Continue)
        {
            // user decided to abort and repair on his own
            // good luck!
            return false;
        }
        need_repair = true;

        // show progress bar again
        progress.show();
        qApp->processEvents();
    }

    // source successfully opened
    m_source = &src;

    // read the wave header
    Kwave::wav_fmt_header_t header;

    unsigned int rate = 0;
    unsigned int bits = 0;

    src.seek(fmt_offset);

    // get the encoded block of data from the mime source
    CHECK(src.size() > static_cast<qint64>(sizeof(Kwave::wav_header_t) + 8))

    // get the header
    src.read(reinterpret_cast<char *>(&header),
             sizeof(Kwave::wav_fmt_header_t));
    header.min.format      = qFromLittleEndian<quint16>(header.min.format);
    header.min.channels    = qFromLittleEndian<quint16>(header.min.channels);
    header.min.samplerate  = qFromLittleEndian<quint32>(header.min.samplerate);
    header.min.bytespersec = qFromLittleEndian<quint32>(header.min.bytespersec);
    header.min.blockalign  = qFromLittleEndian<quint16>(header.min.blockalign);
    header.min.bitwidth    = qFromLittleEndian<quint16>(header.min.bitwidth);

    unsigned int tracks = header.min.channels;
    rate = header.min.samplerate;
    bits = header.min.bitwidth;

    Kwave::WavFormatMap known_formats;
    QString format_name = known_formats.findName(header.min.format);

//     qDebug("-------------------------");
//     qDebug("wav header:");
//     qDebug("format      = 0x%04X, (%s)", header.min.format,
//                                          DBG(format_name));
//     qDebug("channels    = %d", header.min.channels);
//     qDebug("rate        = %u", header.min.samplerate);
//     qDebug("bytes/s     = %u", header.min.bytespersec);
//     qDebug("block align = %d", header.min.blockalign);
//     qDebug("bits/sample = %d", header.min.bitwidth);
//     qDebug("-------------------------");

    // open the file through libaudiofile :)
    if (need_repair) {
        QList<Kwave::RecoverySource *> *repair_list =
            new(std::nothrow) QList<Kwave::RecoverySource *>();
        Q_ASSERT(repair_list);
        if (!repair_list) return false;

        Kwave::RIFFChunk *root = (riff_chunk) ? riff_chunk :
                                                parser.findChunk("");
//      parser.dumpStructure();
//      qDebug("riff chunk = %p, parser.findChunk('')=%p", riff_chunk,
//          parser.findChunk(""));
        repair(repair_list, root, fmt_chunk, data_chunk);
        m_src_adapter = new(std::nothrow)
            Kwave::RepairVirtualAudioFile(*m_source, repair_list);
    } else {
        m_src_adapter = new(std::nothrow) Kwave::VirtualAudioFile(*m_source);
    }

    Q_ASSERT(m_src_adapter);
    if (!m_src_adapter) return false;

    m_src_adapter->open(m_src_adapter, nullptr);

    AFfilehandle fh = m_src_adapter->handle();
    if (!fh || (m_src_adapter->lastError() >= 0)) {
        QString reason;

        switch (m_src_adapter->lastError()) {
            case AF_BAD_NOT_IMPLEMENTED:
                reason = i18n("Format or function is not implemented") +
                         _("\n(") + format_name + _(")");
                break;
            case AF_BAD_MALLOC:
                reason = i18n("Out of memory");
                break;
            case AF_BAD_HEADER:
                reason = i18n("file header is damaged");
                break;
            case AF_BAD_CODEC_TYPE:
                reason = i18n("Invalid codec type") +
                         _("\n(") + format_name + _(")");
                break;
            case AF_BAD_OPEN:
                reason = i18n("Opening the file failed");
                break;
            case AF_BAD_READ:
                reason = i18n("Read access failed");
                break;
            case AF_BAD_SAMPFMT:
                reason = i18n("Invalid sample format");
                break;
            default:
                reason = i18n("internal libaudiofile error #%1: '%2'",
                    m_src_adapter->lastError(),
                    m_src_adapter->lastErrorText()
                );
        }

        QString text= i18n("An error occurred while opening the file:\n'%1'",
                            reason);
        Kwave::MessageBox::error(widget, text);

        return false;
    }

    AFframecount length = afGetFrameCount(fh, AF_DEFAULT_TRACK);
    tracks = afGetVirtualChannels(fh, AF_DEFAULT_TRACK);

    int af_sample_format;
    afGetVirtualSampleFormat(fh, AF_DEFAULT_TRACK, &af_sample_format,
        reinterpret_cast<int *>(&bits));
    if (static_cast<signed int>(bits) < 0) bits = 0;
    Kwave::SampleFormat::Format fmt;
    switch (af_sample_format)
    {
        case AF_SAMPFMT_TWOSCOMP:
            fmt = Kwave::SampleFormat::Signed;
            break;
        case AF_SAMPFMT_UNSIGNED:
            fmt = Kwave::SampleFormat::Unsigned;
            break;
        case AF_SAMPFMT_FLOAT:
            fmt = Kwave::SampleFormat::Float;
            break;
        case AF_SAMPFMT_DOUBLE:
            fmt = Kwave::SampleFormat::Double;
            break;
        default:
            fmt = Kwave::SampleFormat::Unknown;
            break;
    }

    int af_compression = afGetCompression(fh, AF_DEFAULT_TRACK);
    const Kwave::Compression compression(
        Kwave::Compression::fromAudiofile(af_compression)
    );

    info.setRate(rate);
    info.setBits(bits);
    info.setTracks(tracks);
    info.setLength(length);
    info.set(Kwave::INF_SAMPLE_FORMAT, Kwave::SampleFormat(fmt).toInt());
    info.set(Kwave::INF_COMPRESSION, compression.toInt());

    // read in all info from the LIST (INFO) chunk
    Kwave::RIFFChunk *info_chunk = parser.findChunk("/RIFF:WAVE/LIST:INFO");
    if (info_chunk) {
        // found info chunk !
        Kwave::RIFFChunkList &list = info_chunk->subChunks();
        foreach (Kwave::RIFFChunk *chunk, list) {
            if (!chunk) continue;
            if (!m_property_map.containsChunk(chunk->name())) continue;

            // read the content into a QString
            Kwave::FileProperty prop = m_property_map.property(chunk->name());
            unsigned int ofs = chunk->dataStart();
            unsigned int len = chunk->dataLength();
            QByteArray buffer(len + 1, 0x00);
            src.seek(ofs);
            src.read(buffer.data(), len);
            buffer[len] = 0;
            QString value = QString::fromUtf8(buffer);
            if (value.contains(_("\r\n"))) {
                QStringList v = value.split(_("\r\n"),
                    Qt::SkipEmptyParts, Qt::CaseSensitive);
                info.set(prop, v);
            } else {
                info.set(prop, value);
            }
        }
    }

    // read in the Labels (cue list)
    Kwave::RIFFChunk *cue_chunk = parser.findChunk("/RIFF:WAVE/cue ");
    if (cue_chunk) {
        // found a cue list chunk !
        quint32 count;

        src.seek(cue_chunk->dataStart());
        src.read(reinterpret_cast<char *>(&count), 4);
        count = qFromLittleEndian<quint32>(count);
//      unsigned int length = cue_chunk->dataLength();
//      qDebug("cue list found: %u entries, %u bytes (should be: %u)",
//          count, length, count * (6 * 4) + 4);

        for (unsigned int i = 0; i < count; i++) {
            quint32 data, index, position;
            src.seek(cue_chunk->dataStart() + 4 + ((6 * 4) * i));
            /*
             * typedef struct {
             *     quint32 dwIdentifier; <- index
             *     quint32 dwPosition;   <- 0
             *     quint32 fccChunk;     <- 'data'
             *     quint32 dwChunkStart; <- 0
             *     quint32 dwBlockStart; <- 0
             *     quint32 dwSampleOffset; <- label.pos()
             * } cue_list_entry_t;
             */

            /* dwIdentifier */
            src.read(reinterpret_cast<char *>(&data), 4);
            index = qFromLittleEndian<quint32>(data);

            /* dwPosition (ignored) */
            src.read(reinterpret_cast<char *>(&data), 4);

            /* fccChunk */
            src.read(reinterpret_cast<char *>(&data), 4);
            /* we currently support only 'data' */
            if (qstrncmp(reinterpret_cast<const char *>(&data), "data", 4)) {
                qWarning("cue list entry %u refers to '%s', "
                         "which is not supported -> skipped",
                         index, QByteArray(
                         reinterpret_cast<const char *>(&data), 4).data());
                continue;
            }
            src.read(reinterpret_cast<char *>(&data), 4);
            /* dwChunkStart (must be 0) */
            if (data != 0) {
                qWarning("cue list entry %u has dwChunkStart != 0 -> skipped",
                         index);
                continue;
            }
            src.read(reinterpret_cast<char *>(&data), 4);
            /* dwBlockStart (must be 0) */
            if (data != 0) {
                qWarning("cue list entry %u has dwBlockStart != 0 -> skipped",
                         index);
                continue;
            }

            src.read(reinterpret_cast<char *>(&data), 4); /* dwSampleOffset */
            position = qFromLittleEndian<quint32>(data);

            // as we now have index and position, find out the name
            QByteArray name = "";
            Kwave::RIFFChunk *adtl_chunk =
                parser.findChunk("/RIFF:WAVE/LIST:adtl");
            if (adtl_chunk) {
                Kwave::RIFFChunk *labl_chunk = nullptr;
                bool found = false;
                QListIterator<Kwave::RIFFChunk *> it(adtl_chunk->subChunks());
                while (it.hasNext()) {
                    quint32 labl_index;
                    labl_chunk = it.next();
                    /*
                     * typedef struct {
                     *     quint32 dwChunkID;    <- 'labl'
                     *     quint32 dwChunkSize;  (without padding !)
                     *     quint32 dwIdentifier; <- index
                     *     char    dwText[];       <- label->name()
                     * } label_list_entry_t;
                     */
                    if (labl_chunk->name() != "labl") continue;

                    /* dwIdentifier */
                    data = 0;
                    src.seek(labl_chunk->dataStart());
                    src.read(reinterpret_cast<char *>(&data), 4);
                    labl_index = qFromLittleEndian<quint32>(data);
                    if (labl_index == index) {
                        found = true;
                        break; /* found it! */
                    }
                }
                if (found) {
                    Q_ASSERT(labl_chunk);
                    unsigned int len = labl_chunk->length();
                    if (len > 4) {
                        len -= 4;
                        name.resize(len);
                        src.seek(labl_chunk->dataStart() + 4);
                        src.read(static_cast<char *>(name.data()), len);
                        if (name[name.size() - 1] != '\0')
                            name += '\0';
                    }
                }
            }

            if (!name.length()) {
//              qDebug("cue list entry %d has no name", index);
                name = "";
            }

            // put a new label into the list
            QString str = QString::fromUtf8(name);
            labels.append(Kwave::Label(position, str));
        }
    }
    labels.sort();
    metaData().replace(Kwave::MetaDataList(info));
    metaData().replace(labels.toMetaDataList());

    // set up libaudiofile to produce Kwave's internal sample format
#if Q_BYTE_ORDER == Q_BIG_ENDIAN
    afSetVirtualByteOrder(fh, AF_DEFAULT_TRACK, AF_BYTEORDER_BIGENDIAN);
#else
    afSetVirtualByteOrder(fh, AF_DEFAULT_TRACK, AF_BYTEORDER_LITTLEENDIAN);
#endif
    afSetVirtualSampleFormat(fh, AF_DEFAULT_TRACK,
        AF_SAMPFMT_TWOSCOMP, SAMPLE_STORAGE_BITS);

    return true;
}

//***************************************************************************
bool Kwave::WavDecoder::decode(QWidget */*widget*/, Kwave::MultiWriter &dst)
{
    Q_ASSERT(m_src_adapter);
    Q_ASSERT(m_source);
    if (!m_source) return false;
    if (!m_src_adapter) return false;

    AFfilehandle fh = m_src_adapter->handle();
    Q_ASSERT(fh);
    if (!fh) return false;

//     info().dump();
    const unsigned int tracks = dst.tracks();

    // allocate an array of Writers, for speeding up
    QVector<Kwave::Writer *>writers(tracks);
    Q_ASSERT(writers.count() == Kwave::toInt(dst.tracks()));
    if (writers.count() != Kwave::toInt(dst.tracks())) return false;
    for (unsigned int t = 0; t < tracks; t++)
        writers[t] = dst[t];
    Kwave::Writer **writer_fast = writers.data();

    unsigned int frame_size = Kwave::toUint(
        afGetVirtualFrameSize(fh, AF_DEFAULT_TRACK, 1));

    // allocate a buffer for input data
    const unsigned int buffer_frames = (8 * 1024);
    sample_storage_t *buffer = static_cast<sample_storage_t *>(
        malloc(buffer_frames * frame_size));
    Q_ASSERT(buffer);
    if (!buffer) return false;

    // read in from the audiofile source
    Q_ASSERT(tracks == Kwave::FileInfo(metaData()).tracks());
    sample_index_t rest = Kwave::FileInfo(metaData()).length();
    while (rest) {
        unsigned int frames = buffer_frames;
        if (frames > rest) frames = Kwave::toUint(rest);
        unsigned int buffer_used = afReadFrames(fh,
            AF_DEFAULT_TRACK, reinterpret_cast<char *>(buffer), frames);

        // break if eof reached
        if (!buffer_used) break;
        rest -= buffer_used;

        // split into the tracks
        sample_storage_t *p = buffer;
        for (unsigned int count = buffer_used; count; count--) {
            for (unsigned int track = 0; track < tracks; track++) {
                sample_storage_t s = *p++;

                // adjust precision
                if (SAMPLE_STORAGE_BITS != SAMPLE_BITS) {
                    s /= (1 << (SAMPLE_STORAGE_BITS - SAMPLE_BITS));
                }

                // the following cast is only necessary if
                // sample_t is not equal to a sample_storage_t
                Q_ASSERT(writer_fast[track]);
                *(writer_fast[track]) << static_cast<sample_t>(s);
            }
        }

        // abort if the user pressed cancel
        if (dst.isCanceled()) break;
    }

    // return with a valid Signal, even if the user pressed cancel !
    if (buffer) free(buffer);
    return true;
}

//***************************************************************************
bool Kwave::WavDecoder::repairChunk(
    QList<Kwave::RecoverySource *> *repair_list,
    Kwave::RIFFChunk *chunk, quint32 &offset)
{
    Q_ASSERT(chunk);
    Q_ASSERT(m_source);
    Q_ASSERT(repair_list);
    if (!chunk) return false;
    if (!m_source) return false;
    if (!repair_list) return false;

    char buffer[16];
    quint32 length;
    Kwave::RecoverySource *rec_buf = nullptr;

    // create buffer with header
    strncpy(buffer, chunk->name().data(), 4);
    length = (chunk->type() == Kwave::RIFFChunk::Main) ? chunk->physLength() :
                                                         chunk->dataLength();
    buffer[4] = (length      ) & 0xFF;
    buffer[5] = (length >>  8) & 0xFF;
    buffer[6] = (length >> 16) & 0xFF;
    buffer[7] = (length >> 24) & 0xFF;
    if (chunk->type() == Kwave::RIFFChunk::Main) {
        strncpy(&(buffer[8]), chunk->format().data(), 4);
        rec_buf = new(std::nothrow) Kwave::RecoveryBuffer(offset, 12, buffer);
        qDebug("[0x%08X-0x%08X] - main header '%s' (%s), len=%u",
              offset, offset+11, chunk->name().data(),
              chunk->format().data(), length);
        offset += 12;
    } else {
        rec_buf = new(std::nothrow) Kwave::RecoveryBuffer(offset, 8, buffer);
        qDebug("[0x%08X-0x%08X] - sub header '%s', len=%u",
              offset, offset+7, chunk->name().data(), length);
        offset += 8;
    }
    Q_ASSERT(rec_buf);
    if (!rec_buf) return false;
    repair_list->append(rec_buf);

    // map the chunk's data if not main or root
    if ((chunk->type() != Kwave::RIFFChunk::Root) &&
        (chunk->type() != Kwave::RIFFChunk::Main))
    {
        rec_buf = new(std::nothrow) Kwave::RecoveryMapping(
            offset, chunk->physLength(),
            *m_source, chunk->dataStart()
        );
        qDebug("[0x%08X-0x%08X] - restoring from offset 0x%08X (%u)",
              offset, offset+chunk->physLength()-1, chunk->dataStart(),
              chunk->physLength());
        Q_ASSERT(rec_buf);
        if (!rec_buf) return false;
        repair_list->append(rec_buf);

        offset += chunk->physLength();
    }

    // recursively go over all sub-chunks
    Kwave::RIFFChunkList &list = chunk->subChunks();
    foreach (Kwave::RIFFChunk *c, list) {
        if (!c) continue;
        if (!repairChunk(repair_list, c, offset))
            return false;
    }

    return true;
}

//***************************************************************************
bool Kwave::WavDecoder::repair(QList<Kwave::RecoverySource *> *repair_list,
    Kwave::RIFFChunk *riff_chunk,
    Kwave::RIFFChunk *fmt_chunk,
    Kwave::RIFFChunk *data_chunk)
{
    Q_ASSERT(fmt_chunk);
    Q_ASSERT(data_chunk);
    if (!fmt_chunk || !data_chunk) return false;

    // --- first create a chunk tree for the structure ---

    // make a new "RIFF" chunk as root
    Kwave::RIFFChunk new_root(nullptr, "RIFF", "WAVE", 0,0,0);
    new_root.setType(Kwave::RIFFChunk::Main);

    // create a new "fmt " chunk
    Kwave::RIFFChunk *new_fmt = new(std::nothrow)
        Kwave::RIFFChunk(&new_root, "fmt ",nullptr, 0,
        fmt_chunk->physStart(), fmt_chunk->physLength());
    Q_ASSERT(new_fmt);
    if (!new_fmt) return false;
    new_root.subChunks().append(new_fmt);

    // create a new "data" chunk
    Kwave::RIFFChunk *new_data =
        new(std::nothrow) Kwave::RIFFChunk(&new_root, "data", nullptr, 0,
        data_chunk->physStart(), data_chunk->physLength());
    Q_ASSERT(new_data);
    if (!new_data) return false;
    new_root.subChunks().append(new_data);

    // if we have a RIFF chunk, add it's subchunks, except "fmt " and "data"
    // we keep only pointers here, just for getting the right structure,
    // sizes and start positions.
    // NOTE: The sizes might be re-assigned and get invalid afterwards!!!
    if (riff_chunk) {
        Kwave::RIFFChunkList &list = riff_chunk->subChunks();
        foreach (Kwave::RIFFChunk *chunk, list) {
            if (!chunk) continue;
            if (chunk->name() == "fmt ") continue;
            if (chunk->name() == "data") continue;
            if (chunk->name() == "RIFF") continue;
            if (chunk->type() == Kwave::RIFFChunk::Empty) continue;
            if (chunk->type() == Kwave::RIFFChunk::Garbage) continue;

            new_root.subChunks().append(chunk);
        }
    }

    // fix all node sizes (compress)
    new_root.fixSize();

    // attention: some of the offsets belong to source file, some belong
    // to reconstructed buffers! only the sizes are correct.
//    new_root.dumpStructure();

    // --- set up the repair list ---

    // RIFF chunk length
    quint32 offset = 0;
    bool repaired = repairChunk(repair_list, &new_root, offset);

    // clean up...
    new_root.subChunks().clear();
    delete new_fmt;
    delete new_data;

    return (repaired);
}

//***************************************************************************
void Kwave::WavDecoder::close()
{
    delete m_src_adapter;
    m_src_adapter = nullptr;
    m_source = nullptr;
}

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