src/main/java/net/pterodactylus/rhynodge/filters/EpisodeFilter.java

   1 /*
   2  * Rhynodge - EpisodeFilter.java - Copyright © 2013 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.rhynodge.filters;
  19
  20 import static com.google.common.base.Optional.absent;
  21 import static com.google.common.base.Preconditions.checkState;
  22 import static com.google.common.collect.FluentIterable.from;
  23 import static java.util.Arrays.asList;
  24
  25 import java.util.Collection;
  26 import java.util.regex.Matcher;
  27 import java.util.regex.Pattern;
  28
  29 import net.pterodactylus.rhynodge.Filter;
  30 import net.pterodactylus.rhynodge.State;
  31 import net.pterodactylus.rhynodge.states.EpisodeState;
  32 import net.pterodactylus.rhynodge.states.EpisodeState.Episode;
  33 import net.pterodactylus.rhynodge.states.FailedState;
  34 import net.pterodactylus.rhynodge.states.TorrentState;
  35 import net.pterodactylus.rhynodge.states.TorrentState.TorrentFile;
  36
  37 import com.google.common.base.Function;
  38 import com.google.common.base.Optional;
  39 import com.google.common.collect.HashMultimap;
  40 import com.google.common.collect.Multimap;
  41
  42 /**
  43  * {@link Filter} implementation that extracts {@link Episode} information from
  44  * the {@link TorrentFile}s contained in a {@link TorrentState}.
  45  *
  46  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  47  */
  48 public class EpisodeFilter implements Filter {
  49
  50         /** The pattern to parse episode information from the filename. */
  51         private static final Collection<Pattern> episodePatterns = asList(Pattern.compile("[Ss](\\d{2})[Ee](\\d{2})"), Pattern.compile("[^\\d](\\d{1,2})x(\\d{2})[^\\d]"));
  52
  53         //
  54         // FILTER METHODS
  55         //
  56
  57         /**
  58          * {@inheritDoc}
  59          */
  60         @Override
  61         public State filter(State state) {
  62                 if (!state.success()) {
  63                         return FailedState.from(state);
  64                 }
  65                 checkState(state instanceof TorrentState, "state is not a TorrentState but a %s!", state.getClass());
  66
  67                 TorrentState torrentState = (TorrentState) state;
  68                 final Multimap<Episode, TorrentFile> episodes = HashMultimap.create();
  69                 for (TorrentFile torrentFile : torrentState) {
  70                         Optional<Episode> episode = extractEpisode(torrentFile);
  71                         if (!episode.isPresent()) {
  72                                 continue;
  73                         }
  74                         episodes.put(episode.get(), torrentFile);
  75                 }
  76
  77                 return new EpisodeState(from(episodes.keySet()).transform(episodeFiller(episodes)).toSet());
  78         }
  79
  80         //
  81         // STATIC METHODS
  82         //
  83
  84         /**
  85          * Returns a function that creates an {@link Episode} that contains all {@link
  86          * TorrentFile}s.
  87          *
  88          * @param episodeTorrents
  89          *              A multimap mapping episodes to torrent files.
  90          * @return The function that performs the extraction of torrent files
  91          */
  92         private static Function<Episode, Episode> episodeFiller(final Multimap<Episode, TorrentFile> episodeTorrents) {
  93                 return new Function<Episode, Episode>() {
  94                         @Override
  95                         public Episode apply(Episode episode) {
  96                                 Episode completeEpisode = new Episode(episode.season(), episode.episode());
  97                                 for (TorrentFile torrentFile : episodeTorrents.get(episode)) {
  98                                         completeEpisode.addTorrentFile(torrentFile);
  99                                 }
 100                                 return completeEpisode;
 101                         }
 102                 };
 103         }
 104
 105         /**
 106          * Extracts episode information from the given torrent file.
 107          *
 108          * @param torrentFile
 109          *              The torrent file to extract the episode information from
 110          * @return The extracted episode information, or {@link Optional#absent()} if
 111          *         no episode information could be found
 112          */
 113         private static Optional<Episode> extractEpisode(TorrentFile torrentFile) {
 114                 for (Pattern episodePattern : episodePatterns) {
 115                         Matcher matcher = episodePattern.matcher(torrentFile.name());
 116                         if (!matcher.find() || matcher.groupCount() < 2) {
 117                                 continue;
 118                         }
 119                         String seasonString = matcher.group(1);
 120                         String episodeString = matcher.group(2);
 121                         int season = Integer.valueOf(seasonString);
 122                         int episode = Integer.valueOf(episodeString);
 123                         return Optional.of(new Episode(season, episode));
 124                 }
 125                 return absent();
 126         }
 127
 128 }