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 import org.apache.log4j.Logger;
  42 import org.jetbrains.annotations.NotNull;
  43
  44 /**
  45  * {@link Filter} implementation that extracts {@link Episode} information from
  46  * the {@link TorrentFile}s contained in a {@link TorrentState}.
  47  *
  48  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  49  */
  50 public class EpisodeFilter implements Filter {
  51
  52         private static final Logger logger = Logger.getLogger(EpisodeFilter.class);
  53
  54         /** The pattern to parse episode information from the filename. */
  55         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]"));
  56
  57         //
  58         // FILTER METHODS
  59         //
  60
  61         /**
  62          * {@inheritDoc}
  63          */
  64         @NotNull
  65         @Override
  66         public State filter(@NotNull State state) {
  67                 if (!state.success()) {
  68                         return FailedState.from(state);
  69                 }
  70                 checkState(state instanceof TorrentState, "state is not a TorrentState but a %s!", state.getClass());
  71
  72                 TorrentState torrentState = (TorrentState) state;
  73                 final Multimap<Episode, TorrentFile> episodes = HashMultimap.create();
  74                 for (TorrentFile torrentFile : torrentState) {
  75                         Optional<Episode> episode = extractEpisode(torrentFile);
  76                         if (!episode.isPresent()) {
  77                                 continue;
  78                         }
  79                         episodes.put(episode.get(), torrentFile);
  80                 }
  81
  82                 return new EpisodeState(from(episodes.keySet()).transform(episodeFiller(episodes)).toSet());
  83         }
  84
  85         //
  86         // STATIC METHODS
  87         //
  88
  89         /**
  90          * Returns a function that creates an {@link Episode} that contains all {@link
  91          * TorrentFile}s.
  92          *
  93          * @param episodeTorrents
  94          *              A multimap mapping episodes to torrent files.
  95          * @return The function that performs the extraction of torrent files
  96          */
  97         private static Function<Episode, Episode> episodeFiller(final Multimap<Episode, TorrentFile> episodeTorrents) {
  98                 return new Function<Episode, Episode>() {
  99                         @Override
 100                         public Episode apply(Episode episode) {
 101                                 Episode completeEpisode = new Episode(episode.season(), episode.episode());
 102                                 for (TorrentFile torrentFile : episodeTorrents.get(episode)) {
 103                                         completeEpisode.addTorrentFile(torrentFile);
 104                                 }
 105                                 return completeEpisode;
 106                         }
 107                 };
 108         }
 109
 110         /**
 111          * Extracts episode information from the given torrent file.
 112          *
 113          * @param torrentFile
 114          *              The torrent file to extract the episode information from
 115          * @return The extracted episode information, or {@link Optional#absent()} if
 116          *         no episode information could be found
 117          */
 118         private static Optional<Episode> extractEpisode(TorrentFile torrentFile) {
 119                 logger.debug(String.format("Extracting episode from %s...", torrentFile));
 120                 for (Pattern episodePattern : episodePatterns) {
 121                         Matcher matcher = episodePattern.matcher(torrentFile.name());
 122                         if (!matcher.find() || matcher.groupCount() < 2) {
 123                                 continue;
 124                         }
 125                         String seasonString = matcher.group(1);
 126                         String episodeString = matcher.group(2);
 127                         logger.debug(String.format("Parsing %s and %s as season and episode...", seasonString, episodeString));
 128                         int season = Integer.valueOf(seasonString);
 129                         int episode = Integer.valueOf(episodeString);
 130                         return Optional.of(new Episode(season, episode));
 131                 }
 132                 return absent();
 133         }
 134
 135 }