/* This file is part of Clementine.

   Copyright 2010, 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 "core/application.h"
#include "core/logging.h"
#include "covers/albumcoverfetcher.h"
#include "covers/albumcoverloader.h"
#include "library/librarybackend.h"
#include "ui/albumcoverchoicecontroller.h"
#include "ui/albumcovermanager.h"
#include "ui/albumcoversearcher.h"
#include "ui/coverfromurldialog.h"
#include "ui/iconloader.h"

#include <QAction>
#include <QCryptographicHash>
#include <QDialog>
#include <QDragEnterEvent>
#include <QFileDialog>
#include <QImageWriter>
#include <QLabel>
#include <QList>
#include <QMenu>
#include <QUrl>

const char* AlbumCoverChoiceController::kLoadImageFileFilter =
  QT_TR_NOOP("Images (*.png *.jpg *.jpeg *.bmp *.gif *.xpm *.pbm *.pgm *.ppm *.xbm)");
const char* AlbumCoverChoiceController::kSaveImageFileFilter =
  QT_TR_NOOP("Images (*.png *.jpg *.jpeg *.bmp *.xpm *.pbm *.ppm *.xbm)");
const char* AlbumCoverChoiceController::kAllFilesFilter =
  QT_TR_NOOP("All files (*)");

QSet<QString>* AlbumCoverChoiceController::sImageExtensions = NULL;

AlbumCoverChoiceController::AlbumCoverChoiceController(QWidget* parent)
  : QWidget(parent),
    app_(NULL),
    cover_searcher_(NULL),
    cover_fetcher_(NULL),
    save_file_dialog_(NULL),
    cover_from_url_dialog_(NULL)
{
  cover_from_file_ = new QAction(IconLoader::Load("document-open"), tr("Load cover from disk..."), this);
  cover_to_file_ = new QAction(IconLoader::Load("document-save"), tr("Save cover to disk..."), this);
  cover_from_url_ = new QAction(IconLoader::Load("download"), tr("Load cover from URL..."), this);
  search_for_cover_ = new QAction(IconLoader::Load("find"), tr("Search for album covers..."), this);
  unset_cover_ = new QAction(IconLoader::Load("list-remove"), tr("Unset cover"), this);
  show_cover_ = new QAction(IconLoader::Load("zoom-in"), tr("Show fullsize..."), this);

  separator_ = new QAction(this);
  separator_->setSeparator(true);
}

AlbumCoverChoiceController::~AlbumCoverChoiceController()
{
}

void AlbumCoverChoiceController::SetApplication(Application* app) {
  app_ = app;

  cover_fetcher_ = new AlbumCoverFetcher(app_->cover_providers(), this);
  cover_searcher_ = new AlbumCoverSearcher(QIcon(":/nocover.png"), app, this);
  cover_searcher_->Init(cover_fetcher_);
}

QList<QAction*> AlbumCoverChoiceController::GetAllActions() {
  return QList<QAction*>() << cover_from_file_ << cover_to_file_
                           << separator_
                           << cover_from_url_ << search_for_cover_
                           << unset_cover_ << show_cover_;
}

QString AlbumCoverChoiceController::LoadCoverFromFile(Song* song) {
  QString cover = QFileDialog::getOpenFileName(
      this, tr("Load cover from disk"), GetInitialPathForFileDialog(*song, QString()),
      tr(kLoadImageFileFilter) + ";;" + tr(kAllFilesFilter));

  if (cover.isNull())
    return QString();

  // Can we load the image?
  QImage image(cover);

  if(!image.isNull()) {
    SaveCover(song, cover);
    return cover;
  } else {
    return QString();
  }
}

void AlbumCoverChoiceController::SaveCoverToFile(const Song& song, const QImage& image) {
  QString initial_file_name = "/" + (song.album().isEmpty()
                                         ? tr("Unknown")
                                         : song.album()) + ".jpg";

  QString save_filename = QFileDialog::getSaveFileName(
      this, tr("Save album cover"), GetInitialPathForFileDialog(song, initial_file_name),
      tr(kSaveImageFileFilter) + ";;" + tr(kAllFilesFilter));

  if(save_filename.isNull())
    return;

  QString extension = save_filename.right(4);
  if (!extension.startsWith('.') ||
      !QImageWriter::supportedImageFormats().contains(extension.right(3).toUtf8())) {
    save_filename.append(".jpg");
  }

  image.save(save_filename);
}

QString AlbumCoverChoiceController::GetInitialPathForFileDialog(const Song& song,
                                                                const QString& filename) {
  // art automatic is first to show user which cover the album may be
  // using now; the song is using it if there's no manual path but we
  // cannot use manual path here because it can contain cached paths
  if (!song.art_automatic().isEmpty() && !song.has_embedded_cover()) {
    return song.art_automatic();

  // if no automatic art, start in the song's folder
  } else if (!song.url().isEmpty() && song.url().toLocalFile().contains('/')) {
    return song.url().toLocalFile().section('/', 0, -2) + filename;

  // fallback - start in home
  } else {
    return QDir::home().absolutePath() + filename;
  }
}

QString AlbumCoverChoiceController::LoadCoverFromURL(Song* song) {
  if(!cover_from_url_dialog_) {
    cover_from_url_dialog_ = new CoverFromURLDialog(this);
  }

  QImage image = cover_from_url_dialog_->Exec();

  if(!image.isNull()) {
    QString cover = SaveCoverInCache(song->artist(), song->album(), image);
    SaveCover(song, cover);

    return cover;
  } else {
    return QString();
  }
}

QString AlbumCoverChoiceController::SearchForCover(Song* song) {
  // Get something sensible to stick in the search box
  QImage image = cover_searcher_->Exec(song->artist(), song->album());

  if(!image.isNull()) {
    QString cover = SaveCoverInCache(song->artist(), song->album(), image);
    SaveCover(song, cover);

    return cover;
  } else {
    return QString();
  }
}

QString AlbumCoverChoiceController::UnsetCover(Song* song) {
  QString cover = Song::kManuallyUnsetCover;
  SaveCover(song, cover);

  return cover;
}

void AlbumCoverChoiceController::ShowCover(const Song& song) {
  QDialog* dialog = new QDialog(this);
  dialog->setAttribute(Qt::WA_DeleteOnClose, true);

  // Use Artist - Album as the window title
  QString title_text(song.albumartist());
  if (title_text.isEmpty())
    title_text = song.artist();

  if (!song.album().isEmpty())
    title_text += " - " + song.album();

  dialog->setWindowTitle(title_text);

  QLabel* label = new QLabel(dialog);
  label->setPixmap(AlbumCoverLoader::TryLoadPixmap(
      song.art_automatic(), song.art_manual(), song.url().toLocalFile()));

  dialog->resize(label->pixmap()->size());
  dialog->show();
}

void AlbumCoverChoiceController::SaveCover(Song* song, const QString &cover) {
  if(song->is_valid() && song->id() != -1) {
    song->set_art_manual(cover);
    app_->library_backend()->UpdateManualAlbumArtAsync(song->artist(), song->album(), cover);
  }
}

QString AlbumCoverChoiceController::SaveCoverInCache(
    const QString& artist, const QString& album, const QImage& image) {

  // Hash the artist and album into a filename for the image
  QCryptographicHash hash(QCryptographicHash::Sha1);
  hash.addData(artist.toLower().toUtf8().constData());
  hash.addData(album.toLower().toUtf8().constData());

  QString filename(hash.result().toHex() + ".jpg");
  QString path(AlbumCoverLoader::ImageCacheDir() + "/" + filename);

  // Make sure this directory exists first
  QDir dir;
  dir.mkdir(AlbumCoverLoader::ImageCacheDir());

  // Save the image to disk
  image.save(path, "JPG");

  return path;
}

bool AlbumCoverChoiceController::IsKnownImageExtension(const QString& suffix) {
  if (!sImageExtensions) {
    sImageExtensions = new QSet<QString>();
    (*sImageExtensions) << "png" << "jpg" << "jpeg" << "bmp" << "gif" << "xpm"
                        << "pbm" << "pgm" << "ppm" << "xbm";
  }

  return sImageExtensions->contains(suffix);
}

bool AlbumCoverChoiceController::CanAcceptDrag(const QDragEnterEvent* e) {
  foreach (const QUrl& url, e->mimeData()->urls()) {
    const QString suffix = QFileInfo(url.toLocalFile()).suffix().toLower();
    if (IsKnownImageExtension(suffix))
      return true;
  }
  if (e->mimeData()->hasImage()) {
    return true;
  }
  return false;
}

QString AlbumCoverChoiceController::SaveCover(Song* song, const QDropEvent* e) {
  foreach (const QUrl& url, e->mimeData()->urls()) {
    const QString filename = url.toLocalFile();
    const QString suffix = QFileInfo(filename).suffix().toLower();

    if (IsKnownImageExtension(suffix)) {
      SaveCover(song, filename);
      return filename;
    }
  }

  if (e->mimeData()->hasImage()) {
    QImage image = qvariant_cast<QImage>(e->mimeData()->imageData());
    if (!image.isNull()) {
      QString cover_path = SaveCoverInCache(song->artist(), song->album(), image);
      SaveCover(song, cover_path);
      return cover_path;
    }
  }

  return QString();
}