/***************************************************************************
    copyright            : (C) 2003-2004 by Allan Sandfeld Jensen
    email                : kde@carewolf.org
 ***************************************************************************/

/***************************************************************************
 *   This library is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU Lesser General Public License version   *
 *   2.1 as published by the Free Software Foundation.                     *
 *                                                                         *
 *   This library 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     *
 *   Lesser General Public License for more details.                       *
 *                                                                         *
 *   You should have received a copy of the GNU Lesser General Public      *
 *   License along with this library; if not, write to the Free Software   *
 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA         *
 *   02110-1301  USA                                                       *
 *                                                                         *
 *   Alternatively, this file is available under the Mozilla Public        *
 *   License Version 1.1.  You may obtain a copy of the License at         *
 *   http://www.mozilla.org/MPL/                                           *
 ***************************************************************************/

#include <memory>

#include "tbytevector.h"
#include "tstring.h"
#include "tlist.h"
#include "tdebug.h"
#include "tagunion.h"
#include "tpropertymap.h"
#include "tagutils.h"

#include "id3v2header.h"
#include "id3v2tag.h"
#include "id3v1tag.h"
#include "xiphcomment.h"

#include "flacpicture.h"
#include "flacfile.h"
#include "flacmetadatablock.h"
#include "flacunknownmetadatablock.h"

using namespace Strawberry_TagLib::TagLib;

namespace {
typedef List<std::shared_ptr<FLAC::MetadataBlock>> BlockList;
typedef BlockList::Iterator BlockIterator;
typedef BlockList::Iterator BlockConstIterator;

enum { FlacXiphIndex = 0,
  FlacID3v2Index = 1,
  FlacID3v1Index = 2 };

const long long MinPaddingLength = 4096;
const long long MaxPaddingLegnth = 1024 * 1024;

const char LastBlockFlag = '\x80';
}  // namespace

namespace Strawberry_TagLib {
namespace TagLib {
namespace FLAC {
// Enables BlockList::find() to take raw pointers.

bool operator==(std::shared_ptr<MetadataBlock> lhs, MetadataBlock *rhs);
bool operator==(std::shared_ptr<MetadataBlock> lhs, MetadataBlock *rhs) {
  return lhs.get() == rhs;
}
}  // namespace FLAC
}  // namespace TagLib
}  // namespace Strawberry_TagLib

class FLAC::File::FilePrivate {
 public:
  explicit FilePrivate(const ID3v2::FrameFactory *frameFactory) : ID3v2FrameFactory(ID3v2::FrameFactory::instance()),
                                                                  ID3v2Location(-1),
                                                                  ID3v2OriginalSize(0),
                                                                  ID3v1Location(-1),
                                                                  flacStart(0),
                                                                  streamStart(0),
                                                                  scanned(false) {

    if (frameFactory)
      ID3v2FrameFactory = frameFactory;

  }

  const ID3v2::FrameFactory *ID3v2FrameFactory;
  long long ID3v2Location;
  long long ID3v2OriginalSize;

  long long ID3v1Location;

  TripleTagUnion tag;

  std::unique_ptr<AudioProperties> properties;
  ByteVector xiphCommentData;
  BlockList blocks;

  long long flacStart;
  long long streamStart;
  bool scanned;
};

////////////////////////////////////////////////////////////////////////////////
// static members
////////////////////////////////////////////////////////////////////////////////

bool FLAC::File::isSupported(IOStream *stream) {

  // A FLAC file has an ID "fLaC" somewhere. An ID3v2 tag may precede.

  const ByteVector buffer = Utils::readHeader(stream, bufferSize(), true);
  return (buffer.find("fLaC") != ByteVector::npos());

}

////////////////////////////////////////////////////////////////////////////////
// public members
////////////////////////////////////////////////////////////////////////////////

FLAC::File::File(FileName file, bool readProperties, AudioProperties::ReadStyle, ID3v2::FrameFactory *frameFactory) : Strawberry_TagLib::TagLib::File(file), d(new FilePrivate(frameFactory)) {

  if (isOpen())
    read(readProperties);

}

FLAC::File::File(IOStream *stream, bool readProperties, AudioProperties::ReadStyle, ID3v2::FrameFactory *frameFactory) : Strawberry_TagLib::TagLib::File(stream), d(new FilePrivate(frameFactory)) {

  if (isOpen())
    read(readProperties);

}

FLAC::File::~File() {
  delete d;
}

Strawberry_TagLib::TagLib::Tag *FLAC::File::tag() const {
  return &d->tag;
}

PropertyMap FLAC::File::setProperties(const PropertyMap &properties) {
  return xiphComment(true)->setProperties(properties);
}

FLAC::AudioProperties *FLAC::File::audioProperties() const {
  return d->properties.get();
}

bool FLAC::File::save() {

  if (readOnly()) {
    debug("FLAC::File::save() - Cannot save to a read only file.");
    return false;
  }

  if (!isValid()) {
    debug("FLAC::File::save() -- Trying to save invalid file.");
    return false;
  }

  // Create new vorbis comments
  if (!hasXiphComment())
    Tag::duplicate(&d->tag, xiphComment(true), false);

  d->xiphCommentData = xiphComment()->render(false);

  // Replace metadata blocks

  for (BlockIterator it = d->blocks.begin(); it != d->blocks.end(); ++it) {
    if ((*it)->code() == MetadataBlock::VorbisComment) {
      // Set the new Vorbis Comment block
      d->blocks.erase(it);
      break;
    }
  }

  d->blocks.append(std::shared_ptr<MetadataBlock>(new UnknownMetadataBlock(MetadataBlock::VorbisComment, d->xiphCommentData)));

  // Render data for the metadata blocks

  ByteVector data;
  for (BlockConstIterator it = d->blocks.begin(); it != d->blocks.end(); ++it) {
    ByteVector blockData = (*it)->render();
    ByteVector blockHeader = ByteVector::fromUInt32BE(blockData.size());
    blockHeader[0] = (*it)->code();
    data.append(blockHeader);
    data.append(blockData);
  }

  // Compute the amount of padding, and append that to data.

  long long originalLength = d->streamStart - d->flacStart;
  long long paddingLength = originalLength - data.size() - 4;

  if (paddingLength <= 0) {
    paddingLength = MinPaddingLength;
  }
  else {
    // Padding won't increase beyond 1% of the file size or 1MB.

    long long threshold = length() / 100;
    threshold = std::max(threshold, MinPaddingLength);
    threshold = std::min(threshold, MaxPaddingLegnth);

    if (paddingLength > threshold)
      paddingLength = MinPaddingLength;
  }

  ByteVector paddingHeader = ByteVector::fromUInt32BE(paddingLength);
  paddingHeader[0] = static_cast<char>(MetadataBlock::Padding | LastBlockFlag);
  data.append(paddingHeader);
  data.resize(static_cast<size_t>(data.size() + paddingLength));

  // Write the data to the file

  insert(data, d->flacStart, originalLength);

  d->streamStart += (static_cast<long>(data.size()) - originalLength);

  if (d->ID3v1Location >= 0)
    d->ID3v1Location += (static_cast<long>(data.size()) - originalLength);

  // Update ID3 tags

  if (ID3v2Tag() && !ID3v2Tag()->isEmpty()) {

    // ID3v2 tag is not empty. Update the old one or create a new one.

    if (d->ID3v2Location < 0)
      d->ID3v2Location = 0;

    data = ID3v2Tag()->render();
    insert(data, d->ID3v2Location, d->ID3v2OriginalSize);

    d->flacStart += (static_cast<long>(data.size()) - d->ID3v2OriginalSize);
    d->streamStart += (static_cast<long>(data.size()) - d->ID3v2OriginalSize);

    if (d->ID3v1Location >= 0)
      d->ID3v1Location += (static_cast<long>(data.size()) - d->ID3v2OriginalSize);

    d->ID3v2OriginalSize = data.size();
  }
  else {

    // ID3v2 tag is empty. Remove the old one.

    if (d->ID3v2Location >= 0) {
      removeBlock(d->ID3v2Location, d->ID3v2OriginalSize);

      d->flacStart -= d->ID3v2OriginalSize;
      d->streamStart -= d->ID3v2OriginalSize;

      if (d->ID3v1Location >= 0)
        d->ID3v1Location -= d->ID3v2OriginalSize;

      d->ID3v2Location = -1;
      d->ID3v2OriginalSize = 0;
    }
  }

  if (ID3v1Tag() && !ID3v1Tag()->isEmpty()) {

    // ID3v1 tag is not empty. Update the old one or create a new one.

    if (d->ID3v1Location >= 0) {
      seek(d->ID3v1Location);
    }
    else {
      seek(0, End);
      d->ID3v1Location = tell();
    }

    writeBlock(ID3v1Tag()->render());
  }
  else {

    // ID3v1 tag is empty. Remove the old one.

    if (d->ID3v1Location >= 0) {
      truncate(d->ID3v1Location);
      d->ID3v1Location = -1;
    }
  }

  return true;

}

ID3v2::Tag *FLAC::File::ID3v2Tag(bool create) {
  return d->tag.access<ID3v2::Tag>(FlacID3v2Index, create);
}

ID3v1::Tag *FLAC::File::ID3v1Tag(bool create) {
  return d->tag.access<ID3v1::Tag>(FlacID3v1Index, create);
}

Ogg::XiphComment *FLAC::File::xiphComment(bool create) {
  return d->tag.access<Ogg::XiphComment>(FlacXiphIndex, create);
}

List<FLAC::Picture *> FLAC::File::pictureList() {

  List<Picture *> pictures;
  for (BlockConstIterator it = d->blocks.begin(); it != d->blocks.end(); ++it) {
    Picture *picture = dynamic_cast<Picture *>(it->get());
    if (picture) {
      pictures.append(picture);
    }
  }
  return pictures;

}

void FLAC::File::addPicture(Picture *picture) {
  d->blocks.append(std::shared_ptr<Picture>(picture));
}

void FLAC::File::removePicture(Picture *picture) {

  BlockIterator it = d->blocks.find(picture);
  if (it != d->blocks.end())
    d->blocks.erase(it);

}

void FLAC::File::removePictures() {

  for (BlockIterator it = d->blocks.begin(); it != d->blocks.end();) {
    if (dynamic_cast<Picture *>(it->get())) {
      it = d->blocks.erase(it);
    }
    else {
      ++it;
    }
  }

}

void FLAC::File::strip(int tags) {

  if (tags & ID3v1)
    d->tag.set(FlacID3v1Index, nullptr);

  if (tags & ID3v2)
    d->tag.set(FlacID3v2Index, nullptr);

  if (tags & XiphComment) {
    xiphComment()->removeAllFields();
    xiphComment()->removeAllPictures();
  }

}

bool FLAC::File::hasXiphComment() const {
  return !d->xiphCommentData.isEmpty();
}

bool FLAC::File::hasID3v1Tag() const {
  return (d->ID3v1Location >= 0);
}

bool FLAC::File::hasID3v2Tag() const {
  return (d->ID3v2Location >= 0);
}

////////////////////////////////////////////////////////////////////////////////
// private members
////////////////////////////////////////////////////////////////////////////////

void FLAC::File::read(bool readProperties) {

  // Look for an ID3v2 tag

  d->ID3v2Location = Utils::findID3v2(this);

  if (d->ID3v2Location >= 0) {
    d->tag.set(FlacID3v2Index, new ID3v2::Tag(this, d->ID3v2Location, d->ID3v2FrameFactory));
    d->ID3v2OriginalSize = ID3v2Tag()->header()->completeTagSize();
  }

  // Look for an ID3v1 tag

  d->ID3v1Location = Utils::findID3v1(this);

  if (d->ID3v1Location >= 0)
    d->tag.set(FlacID3v1Index, new ID3v1::Tag(this, d->ID3v1Location));

  // Look for FLAC metadata, including vorbis comments

  scan();

  if (!isValid())
    return;

  if (!d->xiphCommentData.isEmpty())
    d->tag.set(FlacXiphIndex, new Ogg::XiphComment(d->xiphCommentData));
  else
    d->tag.set(FlacXiphIndex, new Ogg::XiphComment());

  if (readProperties) {

    // First block should be the stream_info metadata

    const ByteVector infoData = d->blocks.front()->render();

    long long streamLength;

    if (d->ID3v1Location >= 0)
      streamLength = d->ID3v1Location - d->streamStart;
    else
      streamLength = length() - d->streamStart;

    d->properties.reset(new AudioProperties(infoData, streamLength));
  }

}

void FLAC::File::scan() {

  // Scan the metadata pages

  if (d->scanned)
    return;

  if (!isValid())
    return;

  long long nextBlockOffset;

  if (d->ID3v2Location >= 0)
    nextBlockOffset = find("fLaC", d->ID3v2Location + d->ID3v2OriginalSize);
  else
    nextBlockOffset = find("fLaC");

  if (nextBlockOffset < 0) {
    debug("FLAC::File::scan() -- FLAC stream not found");
    setValid(false);
    return;
  }

  nextBlockOffset += 4;
  d->flacStart = nextBlockOffset;

  while (true) {

    seek(nextBlockOffset);
    const ByteVector header = readBlock(4);

    // Header format (from spec):
    // <1> Last-metadata-block flag
    // <7> BLOCK_TYPE
    //    0 : STREAMINFO
    //    1 : PADDING
    //    ..
    //    4 : VORBIS_COMMENT
    //    ..
    //    6 : PICTURE
    //    ..
    // <24> Length of metadata to follow

    const char blockType = header[0] & ~LastBlockFlag;
    const bool isLastBlock = (header[0] & LastBlockFlag) != 0;
    const size_t blockLength = header.toUInt24BE(1);

    // First block should be the stream_info metadata

    if (d->blocks.isEmpty() && blockType != MetadataBlock::StreamInfo) {
      debug("FLAC::File::scan() -- First block should be the stream_info metadata");
      setValid(false);
      return;
    }

    if (blockLength == 0 && blockType != MetadataBlock::Padding && blockType != MetadataBlock::SeekTable) {
      debug("FLAC::File::scan() -- Zero-sized metadata block found");
      setValid(false);
      return;
    }

    const ByteVector data = readBlock(blockLength);
    if (data.size() != blockLength) {
      debug("FLAC::File::scan() -- Failed to read a metadata block");
      setValid(false);
      return;
    }

    std::shared_ptr<MetadataBlock> block;

    // Found the vorbis-comment
    if (blockType == MetadataBlock::VorbisComment) {
      if (d->xiphCommentData.isEmpty()) {
        d->xiphCommentData = data;
        block.reset(new UnknownMetadataBlock(MetadataBlock::VorbisComment, data));
      }
      else {
        debug("FLAC::File::scan() -- multiple Vorbis Comment blocks found, discarding");
      }
    }
    else if (blockType == MetadataBlock::Picture) {
      std::shared_ptr<FLAC::Picture> picture(new FLAC::Picture());
      if (picture->parse(data)) {
        block = picture;
      }
      else {
        debug("FLAC::File::scan() -- invalid picture found, discarding");
      }
    }
    else if (blockType == MetadataBlock::Padding) {
      // Skip all padding blocks.
    }
    else {
      block.reset(new UnknownMetadataBlock(blockType, data));
    }

    if (block)
      d->blocks.append(block);

    nextBlockOffset += blockLength + 4;

    if (isLastBlock)
      break;
  }

  // End of metadata, now comes the datastream

  d->streamStart = nextBlockOffset;

  d->scanned = true;

}