/* This file is part of Clementine.
   Copyright 2013, David Sansome <me@davidsansome.com>

   Clementine 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.

   Clementine 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 Clementine.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "wplparser.h"
#include "core/utilities.h"
#include "version.h"

#include <QXmlStreamReader>

WplParser::WplParser(LibraryBackendInterface* library, QObject* parent)
    : XMLParser(library, parent) {}

bool WplParser::TryMagic(const QByteArray& data) const {
  return data.contains("<?wpl") || data.contains("<smil>");
}

SongList WplParser::Load(QIODevice* device, const QString& playlist_path,
                         const QDir& dir) const {
  SongList ret;

  QXmlStreamReader reader(device);
  if (!Utilities::ParseUntilElement(&reader, "smil") ||
      !Utilities::ParseUntilElement(&reader, "body")) {
    return ret;
  }

  while (!reader.atEnd() && Utilities::ParseUntilElement(&reader, "seq")) {
    ParseSeq(dir, &reader, &ret);
  }
  return ret;
}

void WplParser::ParseSeq(const QDir& dir, QXmlStreamReader* reader,
                         SongList* songs) const {
  while (!reader->atEnd()) {
    QXmlStreamReader::TokenType type = reader->readNext();
    switch (type) {
      case QXmlStreamReader::StartElement: {
        QStringRef name = reader->name();
        if (name == "media") {
          QStringRef src = reader->attributes().value("src");
          if (!src.isEmpty()) {
            Song song = LoadSong(src.toString(), 0, dir);
            if (song.is_valid()) {
              songs->append(song);
            }
          }
        } else {
          Utilities::ConsumeCurrentElement(reader);
        }
        break;
      }
      case QXmlStreamReader::EndElement: {
        if (reader->name() == "seq") {
          return;
        }
        break;
      }
      default:
        break;
    }
  }
}

void WplParser::Save(const SongList& songs, QIODevice* device,
                     const QDir& dir) const {
  QXmlStreamWriter writer(device);
  writer.setAutoFormatting(true);
  writer.setAutoFormattingIndent(2);
  writer.writeProcessingInstruction("wpl", "version=\"1.0\"");

  StreamElement smil("smil", &writer);

  {
    StreamElement head("head", &writer);
    WriteMeta("Generator", "Clementine -- " CLEMENTINE_VERSION_DISPLAY,
              &writer);
    WriteMeta("ItemCount", QString::number(songs.count()), &writer);
  }

  {
    StreamElement body("body", &writer);
    {
      StreamElement seq("seq", &writer);
      for (const Song& song : songs) {
        writer.writeStartElement("media");
        writer.writeAttribute("src", URLOrRelativeFilename(song.url(), dir));
        writer.writeEndElement();
      }
    }
  }
}

void WplParser::WriteMeta(const QString& name, const QString& content,
                          QXmlStreamWriter* writer) const {
  writer->writeStartElement("meta");
  writer->writeAttribute("name", name);
  writer->writeAttribute("content", content);
  writer->writeEndElement();
}
