content: /*
   This file is part of Airsonic.
  
   Airsonic 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.
  
   Airsonic 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 Airsonic.  If not, see <http://www.gnu.org/licenses/>.
  
   Copyright 2016 (C) Airsonic Authors
   Based upon Subsonic, Copyright 2009 (C) Sindre Mehus
   */
  package org.airsonic.player.domain;
  
  import java.util.Comparator;
  
  /**
   * Comparator for sorting media files.
   */
  public class MediaFileComparator implements Comparator<MediaFile> {
  
      private final boolean sortAlbumsByYear;
  
      public MediaFileComparator(boolean sortAlbumsByYear) {
          this.sortAlbumsByYear = sortAlbumsByYear;
      }
  
      public int compare(MediaFile a, MediaFile b) {
  
          // Directories before files.
          if (a.isFile() && b.isDirectory()) {
              return 1;
          }
          if (a.isDirectory() && b.isFile()) {
              return -1;
          }
  
          // Non-album directories before album directories.
          if (a.isAlbum() && b.getMediaType() == MediaFile.MediaType.DIRECTORY) {
              return 1;
          }
          if (a.getMediaType() == MediaFile.MediaType.DIRECTORY && b.isAlbum()) {
              return -1;
          }
  
          // Sort albums by year
          if (sortAlbumsByYear && a.isAlbum() && b.isAlbum()) {
              int i = nullSafeCompare(a.getYear(), b.getYear(), false);
              if (i != 0) {
                  return i;
              }
          }
  
          if (a.isDirectory() && b.isDirectory()) {
              int n = a.getName().compareToIgnoreCase(b.getName());
              return n == 0 ? a.getPath().compareToIgnoreCase(b.getPath()) : n; // To make it consistent to MediaFile.equals()
          }
  
          // Compare by disc and track numbers, if present.
          Integer trackA = getSortableDiscAndTrackNumber(a);
          Integer trackB = getSortableDiscAndTrackNumber(b);
          int i = nullSafeCompare(trackA, trackB, false);
          if (i != 0) {
              return i;
          }
  
          return a.getPath().compareToIgnoreCase(b.getPath());
      }
  
      private <T extends Comparable<T>> int nullSafeCompare(T a, T b, boolean nullIsSmaller) {
          if (a == null && b == null) {
              return 0;
          }
          if (a == null) {
              return nullIsSmaller ? -1 : 1;
          }
          if (b == null) {
              return nullIsSmaller ? 1 : -1;
          }
          return a.compareTo(b);
      }
  
      private Integer getSortableDiscAndTrackNumber(MediaFile file) {
          if (file.getTrackNumber() == null) {
              return null;
          }
  
          int discNumber = file.getDiscNumber() == null ? 1 : file.getDiscNumber();
          return discNumber * 1000 + file.getTrackNumber();
      }
  }
  
  