src/main/java/net/pterodactylus/demoscenemusic/data/DataManager.java

   1 /*
   2  * DemosceneMusic - DataManager.java - Copyright © 2012 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.demoscenemusic.data;
  19
  20 import java.sql.ResultSet;
  21 import java.sql.SQLException;
  22 import java.util.Collection;
  23 import java.util.EnumMap;
  24 import java.util.HashSet;
  25 import java.util.List;
  26 import java.util.Map;
  27 import java.util.Map.Entry;
  28 import java.util.UUID;
  29 import java.util.concurrent.Callable;
  30
  31 import net.pterodactylus.demoscenemusic.data.Track.Relationship;
  32 import net.pterodactylus.util.collection.Memoizer;
  33 import net.pterodactylus.util.database.Database;
  34 import net.pterodactylus.util.database.DatabaseException;
  35 import net.pterodactylus.util.database.Field;
  36 import net.pterodactylus.util.database.Join;
  37 import net.pterodactylus.util.database.Join.JoinType;
  38 import net.pterodactylus.util.database.ObjectCreator;
  39 import net.pterodactylus.util.database.ObjectCreator.StringCreator;
  40 import net.pterodactylus.util.database.OrderField;
  41 import net.pterodactylus.util.database.Parameter.IntegerParameter;
  42 import net.pterodactylus.util.database.Parameter.StringParameter;
  43 import net.pterodactylus.util.database.Query;
  44 import net.pterodactylus.util.database.Query.Type;
  45 import net.pterodactylus.util.database.ResultProcessor;
  46 import net.pterodactylus.util.database.ValueField;
  47 import net.pterodactylus.util.database.ValueFieldWhereClause;
  48
  49 /**
  50  * Interface between the database and the application.
  51  *
  52  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  53  */
  54 public class DataManager {
  55
  56         /** The artist object creator. */
  57         @SuppressWarnings("synthetic-access")
  58         private final ObjectCreator<Artist> artistCreator = new ArtistCreator();
  59
  60         /** The group object creator. */
  61         @SuppressWarnings("synthetic-access")
  62         private final ObjectCreator<Group> groupCreator = new GroupCreator();
  63
  64         /** The track object creator. */
  65         @SuppressWarnings("synthetic-access")
  66         private final ObjectCreator<Track> trackCreator = new TrackCreator();
  67
  68         /** The track object creator. */
  69         @SuppressWarnings("synthetic-access")
  70         private final ObjectCreator<TrackDerivative> trackDerivativeCreator = new TrackDerivativeCreator();
  71
  72         /** The style object creator. */
  73         @SuppressWarnings("synthetic-access")
  74         private final ObjectCreator<Style> styleCreator = new StyleCreator();
  75
  76         /** The party object creator. */
  77         @SuppressWarnings("synthetic-access")
  78         private final ObjectCreator<Party> partyCreator = new PartyCreator();
  79
  80         /** The {@link User} object creator. */
  81         @SuppressWarnings("synthetic-access")
  82         private final ObjectCreator<User> userCreator = new UserCreator();
  83
  84         /** The database. */
  85         private final Database database;
  86
  87         /**
  88          * Creates a new data manager.
  89          *
  90          * @param database
  91          *            The database to operate on
  92          */
  93         public DataManager(Database database) {
  94                 this.database = database;
  95         }
  96
  97         /**
  98          * Returns all artists.
  99          *
 100          * @return All artists
 101          * @throws DatabaseException
 102          *             if a database error occurs
 103          */
 104         public Collection<Artist> getAllArtists() throws DatabaseException {
 105                 Query query = new Query(Type.SELECT, "ARTISTS");
 106                 query.addField(new Field("ARTISTS.*"));
 107                 return loadArtistProperties(database.getMultiple(query, artistCreator));
 108         }
 109
 110         /**
 111          * Returns the artist with the given ID.
 112          *
 113          * @param id
 114          *            The ID of the artist
 115          * @return The artist with the given ID, or {@code null} if there is no
 116          *         artist with the given ID
 117          * @throws DatabaseException
 118          *             if a database error occurs
 119          */
 120         public Artist getArtistById(String id) throws DatabaseException {
 121                 Query query = new Query(Type.SELECT, "ARTISTS");
 122                 query.addField(new Field("ARTISTS.*"));
 123                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("ARTISTS.ID", new StringParameter(id))));
 124                 return loadArtistProperties(database.getSingle(query, artistCreator));
 125         }
 126
 127         /**
 128          * Returns all artists that belong to the group with the given ID.
 129          *
 130          * @param groupId
 131          *            The ID of the group
 132          * @return All artists belonging to the given group
 133          * @throws DatabaseException
 134          *             if a database error occurs
 135          */
 136         public Collection<Artist> getArtistsByGroup(String groupId) throws DatabaseException {
 137                 Query query = new Query(Type.SELECT, "ARTISTS");
 138                 query.addField(new Field("ARTISTS.*"));
 139                 query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("ARTISTS.ID"), new Field("GROUP_ARTISTS.ARTIST")));
 140                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.GROUP_", new StringParameter(groupId))));
 141                 return loadArtistProperties(database.getMultiple(query, artistCreator));
 142         }
 143
 144         /**
 145          * Returns all artists involved in the track with the given ID.
 146          *
 147          * @param trackId
 148          *            The ID of the track
 149          * @return All artists involved in the track, in preferred order
 150          * @throws DatabaseException
 151          *             if a database error occurs
 152          */
 153         public List<Artist> getArtistsByTrack(String trackId) throws DatabaseException {
 154                 Query query = new Query(Type.SELECT, "ARTISTS");
 155                 query.addField(new Field("ARTISTS.*"));
 156                 query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACK_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
 157                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.TRACK", new StringParameter(trackId))));
 158                 query.addOrderField(new OrderField(new Field("TRACK_ARTISTS.DISPLAY_ORDER")));
 159                 return loadArtistProperties(database.getMultiple(query, artistCreator));
 160         }
 161
 162         /**
 163          * Creates a new artist with the given name.
 164          *
 165          * @param name
 166          *            The name of the artist
 167          * @return The created artist
 168          * @throws DatabaseException
 169          *             if a database error occurs
 170          */
 171         public Artist createArtist(String name) throws DatabaseException {
 172                 Query query = new Query(Type.INSERT, "ARTISTS");
 173                 String id = UUID.randomUUID().toString();
 174                 query.addValueField(new ValueField("ID", new StringParameter(id)));
 175                 query.addValueField(new ValueField("NAME", new StringParameter(name)));
 176                 database.insert(query);
 177                 return loadArtistProperties(getArtistById(id));
 178         }
 179
 180         /**
 181          * Saves the given artist.
 182          *
 183          * @param artist
 184          *            The artist to save
 185          * @throws DatabaseException
 186          *             if a database error occurs
 187          */
 188         public void saveArtist(Artist artist) throws DatabaseException {
 189                 Query query = new Query(Type.UPDATE, "ARTISTS");
 190                 query.addValueField(new ValueField("NAME", new StringParameter(artist.getName())));
 191                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("ID", new StringParameter(artist.getId()))));
 192                 database.update(query);
 193                 saveArtistProperties(artist);
 194         }
 195
 196         /**
 197          * Saves the properties of the given artist.
 198          *
 199          * @param artist
 200          *            The artist whose properties to save
 201          * @throws DatabaseException
 202          *             if a database error occurs
 203          */
 204         public void saveArtistProperties(Artist artist) throws DatabaseException {
 205                 saveProperties(artist.getProperties(), "ARTIST_PROPERTIES", "ARTIST", artist.getId());
 206         }
 207
 208         /**
 209          * Saves the given properties to the given table for the given principal.
 210          *
 211          * @param properties
 212          *            The properties to save
 213          * @param table
 214          *            The table in which to save the properties
 215          * @param type
 216          *            The type of the principal (e. g. “ARTIST” or “TRACK”)
 217          * @param id
 218          *            The ID of the principial
 219          * @throws DatabaseException
 220          *             if a database error occurs
 221          */
 222         public void saveProperties(Properties properties, String table, String type, String id) throws DatabaseException {
 223                 if (!properties.isDirty()) {
 224                         return;
 225                 }
 226                 Query query = new Query(Type.DELETE, table);
 227                 query.addWhereClause(new ValueFieldWhereClause(new ValueField(type, new StringParameter(id))));
 228                 database.update(query);
 229                 for (Entry<String, String> property : properties) {
 230                         Query insertQuery = new Query(Type.INSERT, table);
 231                         insertQuery.addValueField(new ValueField(type, new StringParameter(id)));
 232                         insertQuery.addValueField(new ValueField("PROPERTY", new StringParameter(property.getKey())));
 233                         insertQuery.addValueField(new ValueField("VALUE", new StringParameter(property.getValue())));
 234                         database.insert(insertQuery);
 235                 }
 236                 properties.resetDirty();
 237         }
 238
 239         /**
 240          * Loads the properties for an artist.
 241          *
 242          * @param artist
 243          *            The artist to load the properties for
 244          * @return The artist
 245          * @throws DatabaseException
 246          *             if a database error occurs
 247          */
 248         public Artist loadArtistProperties(final Artist artist) throws DatabaseException {
 249                 return loadProperties(artist, "ARTIST_PROPERTIES", "ARTIST");
 250         }
 251
 252         /**
 253          * Loads the properties of all given artists.
 254          *
 255          * @param artists
 256          *            The artists to load the properties for
 257          * @return The list of artists
 258          * @throws DatabaseException
 259          *             if a database error occurs
 260          */
 261         public List<Artist> loadArtistProperties(List<Artist> artists) throws DatabaseException {
 262                 for (Artist artist : artists) {
 263                         loadArtistProperties(artist);
 264                 }
 265                 return artists;
 266         }
 267
 268         /**
 269          * Returns all remix artists involved in the track with the given ID.
 270          *
 271          * @param trackId
 272          *            The ID of the track
 273          * @return All remix artists involved in the track, in preferred order
 274          * @throws DatabaseException
 275          *             if a database error occurs
 276          */
 277         public List<Artist> getRemixArtistsByTrack(String trackId) throws DatabaseException {
 278                 Query query = new Query(Type.SELECT, "ARTISTS");
 279                 query.addField(new Field("ARTISTS.*"));
 280                 query.addJoin(new Join(JoinType.INNER, "TRACK_REMIX_ARTISTS", new Field("TRACK_REMIX_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
 281                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_REMIX_ARTISTS.TRACK", new StringParameter(trackId))));
 282                 query.addOrderField(new OrderField(new Field("TRACK_REMIX_ARTISTS.DISPLAY_ORDER")));
 283                 return database.getMultiple(query, artistCreator);
 284         }
 285
 286         /**
 287          * Returns all related tracks for the track with the given ID.
 288          *
 289          * @param trackId
 290          *            The ID of the tracks
 291          * @return A mapping from relationship to all tracks that match the relation
 292          * @throws DatabaseException
 293          *             if a database error occurs
 294          */
 295         public Map<Relationship, Collection<Track>> getRelatedTracksByTrack(String trackId) throws DatabaseException {
 296                 Query query = new Query(Type.SELECT, "TRACKS");
 297                 query.addField(new Field("TRACKS.*"));
 298                 query.addField(new Field("TRACK_RELATIONS.*"));
 299                 query.addJoin(new Join(JoinType.INNER, "TRACK_RELATIONS", new Field("TRACK_RELATIONS.TRACK"), new Field("TRACK_RELATIONS.RELATED_TRACK")));
 300                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_RELATIONS.TRACK", new StringParameter(trackId))));
 301                 final Map<Relationship, Collection<Track>> relatedTracks = new EnumMap<Relationship, Collection<Track>>(Relationship.class);
 302                 database.process(query, new ResultProcessor() {
 303
 304                         @Override
 305                         @SuppressWarnings("synthetic-access")
 306                         public void processResult(ResultSet resultSet) throws SQLException {
 307                                 Track track = trackCreator.createObject(resultSet);
 308                                 Relationship relationship = Relationship.valueOf(resultSet.getString("TRACK_RELATIONS.RELATIONSHIP"));
 309                                 if (!relatedTracks.containsKey(relationship)) {
 310                                         relatedTracks.put(relationship, new HashSet<Track>());
 311                                 }
 312                                 relatedTracks.get(relationship).add(track);
 313                         }
 314                 });
 315                 return relatedTracks;
 316         }
 317
 318         /**
 319          * Returns the track with the given ID.
 320          *
 321          * @param id
 322          *            The ID of the track
 323          * @return The track with the given ID, or {@code null} if there is no such
 324          *         track
 325          * @throws DatabaseException
 326          *             if a database error occurs
 327          */
 328         public Track getTrackById(String id) throws DatabaseException {
 329                 Query query = new Query(Type.SELECT, "TRACKS");
 330                 query.addField(new Field("TRACKS.*"));
 331                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACKS.ID", new StringParameter(id))));
 332                 return loadTrackProperties(database.getSingle(query, trackCreator));
 333         }
 334
 335         /**
 336          * Returns the track that contains the derivative with the given ID.
 337          *
 338          * @param id
 339          *            The ID of the track derivative
 340          * @return The track the derivative belongs to, or {@code null} if there is
 341          *         no such track
 342          * @throws DatabaseException
 343          *             if a database error occurs
 344          */
 345         public Track getTrackByDerivativeId(String id) throws DatabaseException {
 346                 Query query = new Query(Type.SELECT, "TRACKS");
 347                 query.addField(new Field("TRACKS.*"));
 348                 query.addJoin(new Join(JoinType.INNER, "TRACK_DERIVATIVES", new Field("TRACK_DERIVATIVES.TRACK"), new Field("TRACKS.ID")));
 349                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_DERIVATIVES.ID", new StringParameter(id))));
 350                 return loadTrackProperties(database.getSingle(query, trackCreator));
 351         }
 352
 353         /**
 354          * Returns all tracks by the artist with the given ID.
 355          *
 356          * @param artistId
 357          *            The ID of the artist
 358          * @return All tracks by the given artist
 359          * @throws DatabaseException
 360          *             if a database error occurs
 361          */
 362         public Collection<Track> getTracksByArtist(String artistId) throws DatabaseException {
 363                 Query query = new Query(Type.SELECT, "TRACKS");
 364                 query.addField(new Field("TRACKS.*"));
 365                 query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACKS.ID"), new Field("TRACK_ARTISTS.TRACK")));
 366                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.ARTIST", new StringParameter(artistId))));
 367                 return loadTrackProperties(database.getMultiple(query, trackCreator));
 368         }
 369
 370         /**
 371          * Returns all tracks that were released at the party with the given ID.
 372          *
 373          * @param partyId
 374          *            The ID of the party
 375          * @return All tracks that were released at the given party
 376          * @throws DatabaseException
 377          *             if a database error occurs
 378          */
 379         public Collection<Track> getTracksByParty(String partyId) throws DatabaseException {
 380                 Query query = new Query(Type.SELECT, "TRACKS");
 381                 query.addField(new Field("TRACKS.*"));
 382                 query.addJoin(new Join(JoinType.INNER, "PARTY_TRACKS", new Field("PARTY_TRACKS.TRACK"), new Field("TRACKS.ID")));
 383                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("PARTY_TRACKS.PARTY", new StringParameter(partyId))));
 384                 return loadTrackProperties(database.getMultiple(query, trackCreator));
 385         }
 386
 387         /**
 388          * Loads the properties for the given track.
 389          *
 390          * @param track
 391          *            The track for which to load the properties
 392          * @return The track with the properties loaded
 393          * @throws DatabaseException
 394          *             if a database error occurs
 395          */
 396         public Track loadTrackProperties(Track track) throws DatabaseException {
 397                 return loadProperties(track, "TRACK_PROPERTIES", "TRACK");
 398         }
 399
 400         /**
 401          * Loads the properties for the given tracks.
 402          *
 403          * @param tracks
 404          *            The tracks for which to load the properties
 405          * @return The tracks with the properties loaded
 406          * @throws DatabaseException
 407          *             if a database error occurs
 408          */
 409         public List<Track> loadTrackProperties(List<Track> tracks) throws DatabaseException {
 410                 for (Track track : tracks) {
 411                         loadTrackProperties(track);
 412                 }
 413                 return tracks;
 414         }
 415
 416         /**
 417          * Creates a new track with the given name.
 418          *
 419          * @param name
 420          *            The name of the track
 421          * @return The created track
 422          * @throws DatabaseException
 423          *             if a database error occurs
 424          */
 425         public Track createTrack(String name) throws DatabaseException {
 426                 Query query = new Query(Type.INSERT, "TRACKS");
 427                 String id = UUID.randomUUID().toString();
 428                 query.addValueField(new ValueField("ID", new StringParameter(id)));
 429                 query.addValueField(new ValueField("NAME", new StringParameter(name)));
 430                 database.insert(query);
 431                 return getTrackById(id);
 432         }
 433
 434         /**
 435          * Saves the given track. This also saves all relationships of the track.
 436          *
 437          * @param track
 438          *            The track to save
 439          * @throws DatabaseException
 440          *             if a database error occurs
 441          */
 442         public void saveTrack(Track track) throws DatabaseException {
 443                 Query query = new Query(Type.UPDATE, "TRACKS");
 444                 query.addValueField(new ValueField("TRACKS.NAME", new StringParameter(track.getName())));
 445                 query.addValueField(new ValueField("TRACKS.REMIX", new StringParameter(track.getRemix())));
 446                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACKS.ID", new StringParameter(track.getId()))));
 447                 database.update(query);
 448                 /* store artist information. */
 449                 track.getArtists(); /* prefetch artists. */
 450                 query = new Query(Type.DELETE, "TRACK_ARTISTS");
 451                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.TRACK", new StringParameter(track.getId()))));
 452                 database.update(query);
 453                 for (int index = 0; index < track.getArtists().size(); ++index) {
 454                         query = new Query(Type.INSERT, "TRACK_ARTISTS");
 455                         query.addValueField(new ValueField("TRACK_ARTISTS.TRACK", new StringParameter(track.getId())));
 456                         query.addValueField(new ValueField("TRACK_ARTISTS.ARTIST", new StringParameter(track.getArtists().get(index).getId())));
 457                         query.addValueField(new ValueField("TRACK_ARTISTS.DISPLAY_ORDER", new IntegerParameter(index + 1)));
 458                         database.insert(query);
 459                 }
 460                 /* store properties. */
 461                 saveProperties(track.getProperties(), "TRACK_PROPERTIES", "TRACK", track.getId());
 462         }
 463
 464         /**
 465          * Returns the derivative with the given ID.
 466          *
 467          * @param id
 468          *            The ID of the derivatives to load
 469          * @return The derivative with the given ID
 470          * @throws DatabaseException
 471          *             if a database error occurs
 472          */
 473         public TrackDerivative getTrackDerivativeById(String id) throws DatabaseException {
 474                 Query query = new Query(Type.SELECT, "TRACK_DERIVATIVES");
 475                 query.addField(new Field("TRACK_DERIVATIVES.*"));
 476                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_DERIVATIVES.ID", new StringParameter(id))));
 477                 return loadTrackDerivativeProperties(database.getSingle(query, trackDerivativeCreator));
 478         }
 479
 480         /**
 481          * Returns the derivatives for the given track.
 482          *
 483          * @param trackId
 484          *            The track ID to get the derivatives for
 485          * @return The derivatives for the given track
 486          * @throws DatabaseException
 487          *             if a database error occurs
 488          */
 489         public Collection<TrackDerivative> getTrackDerivativesByTrack(String trackId) throws DatabaseException {
 490                 Query query = new Query(Type.SELECT, "TRACK_DERIVATIVES");
 491                 query.addField(new Field("TRACK_DERIVATIVES.*"));
 492                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_DERIVATIVES.TRACK", new StringParameter(trackId))));
 493                 return loadTrackDerivativeProperties(database.getMultiple(query, trackDerivativeCreator));
 494         }
 495
 496         /**
 497          * Creates a new derivative for the given track.
 498          *
 499          * @param track
 500          *            The track to create the derivative for
 501          * @return The created derivative
 502          * @throws DatabaseException
 503          *             if a database error occurs
 504          */
 505         public TrackDerivative createTrackDerivative(Track track) throws DatabaseException {
 506                 Query query = new Query(Type.INSERT, "TRACK_DERIVATIVES");
 507                 String id = UUID.randomUUID().toString();
 508                 query.addValueField(new ValueField("TRACK_DERIVATIVES.ID", new StringParameter(id)));
 509                 query.addValueField(new ValueField("TRACK_DERIVATIVES.TRACK", new StringParameter(track.getId())));
 510                 database.insert(query);
 511                 return getTrackDerivativeById(id);
 512         }
 513
 514         /**
 515          * Loads the properties for the given track derivative.
 516          *
 517          * @param trackDerivative
 518          *            The track derivative to load the properties for
 519          * @return The track derivative with its properties loaded
 520          * @throws DatabaseException
 521          *             if a database error occurs
 522          */
 523         public TrackDerivative loadTrackDerivativeProperties(TrackDerivative trackDerivative) throws DatabaseException {
 524                 return loadProperties(trackDerivative, "TRACK_DERIVATIVE_PROPERTIES", "TRACK_DERIVATIVE");
 525         }
 526
 527         /**
 528          * Loads the properties for the given track derivatives.
 529          *
 530          * @param trackDerivatives
 531          *            The track derivatives to load the properties for
 532          * @return The track derivatives with their properties loaded
 533          * @throws DatabaseException
 534          *             if a database error occurs
 535          */
 536         public List<TrackDerivative> loadTrackDerivativeProperties(List<TrackDerivative> trackDerivatives) throws DatabaseException {
 537                 for (TrackDerivative trackDerivative : trackDerivatives) {
 538                         loadTrackDerivativeProperties(trackDerivative);
 539                 }
 540                 return trackDerivatives;
 541         }
 542
 543         /**
 544          * Saves the given track derivative. As a track derivative does not have any
 545          * attributes of its own only its properties are saved.
 546          *
 547          * @param trackDerivative
 548          *            The track derivative to save
 549          * @throws DatabaseException
 550          *             if a database error occurs
 551          */
 552         public void saveTrackDerivate(TrackDerivative trackDerivative) throws DatabaseException {
 553                 saveProperties(trackDerivative.getProperties(), "TRACK_DERIVATIVE_PROPERTIES", "TRACK_DERIVATIVE", trackDerivative.getId());
 554         }
 555
 556         /**
 557          * Removes the given track derivative and all its properties from the
 558          * database.
 559          *
 560          * @param trackDerivative
 561          *            The track derivative to remove
 562          * @throws DatabaseException
 563          *             if a database error occurs
 564          */
 565         public void removeTrackDerivative(TrackDerivative trackDerivative) throws DatabaseException {
 566                 Query query = new Query(Type.DELETE, "TRACK_DERIVATIVES");
 567                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_DERIVATIVES.ID", new StringParameter(trackDerivative.getId()))));
 568                 database.update(query);
 569                 /* remove the properties. */
 570                 saveProperties(new Properties().set("dirty", "true").removeAll(), "TRACK_DERIVATIVE_PROPERTIES", "TRACK_DERIVATIVE", trackDerivative.getId());
 571         }
 572
 573         /**
 574          * Returns all groups the artist with the given ID belongs to.
 575          *
 576          * @param artistId
 577          *            The ID of the artist
 578          * @return All groups the artist belongs to
 579          * @throws DatabaseException
 580          *             if a database error occurs
 581          */
 582         public Collection<Group> getGroupsByArtist(String artistId) throws DatabaseException {
 583                 Query query = new Query(Type.SELECT, "GROUPS");
 584                 query.addField(new Field("GROUPS.*"));
 585                 query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("GROUPS.ID"), new Field("GROUP_ARTISTS.GROUP_")));
 586                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.ARTIST", new StringParameter(artistId))));
 587                 return database.getMultiple(query, groupCreator);
 588         }
 589
 590         /**
 591          * Returns all styles for the track with the given ID.
 592          *
 593          * @param trackId
 594          *            The ID of the track
 595          * @return All styles for the given track
 596          * @throws DatabaseException
 597          *             if a database error occurs
 598          */
 599         public Collection<Style> getStylesByTrack(String trackId) throws DatabaseException {
 600                 Query query = new Query(Type.SELECT, "STYLES");
 601                 query.addField(new Field("STYLES.*"));
 602                 query.addJoin(new Join(JoinType.INNER, "TRACK_STYLES", new Field("STYLES.ID"), new Field("TRACK_STYLES.STYLE")));
 603                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_STYLES.TRACK", new StringParameter(trackId))));
 604                 return database.getMultiple(query, styleCreator);
 605         }
 606
 607         /**
 608          * Returns all parties.
 609          *
 610          * @return All parties
 611          * @throws DatabaseException
 612          *             if a database error occurs
 613          */
 614         public Collection<Party> getAllParties() throws DatabaseException {
 615                 Query query = new Query(Type.SELECT, "PARTIES");
 616                 query.addField(new Field("PARTIES.*"));
 617                 return loadPartyProperties(database.getMultiple(query, partyCreator));
 618         }
 619
 620         /**
 621          * Returns the user with the given name.
 622          *
 623          * @param username
 624          *            The name of the user
 625          * @return The user, or {@code null} if the user does not exist
 626          * @throws DatabaseException
 627          *             if a database error occurs
 628          */
 629         public User getUserByName(String username) throws DatabaseException {
 630                 Query query = new Query(Type.SELECT, "USERS");
 631                 query.addField(new Field("USERS.*"));
 632                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USERS.NAME", new StringParameter(username))));
 633                 return database.getSingle(query, userCreator);
 634         }
 635
 636         /**
 637          * Returns the user connected with the given OpenID.
 638          *
 639          * @param openId
 640          *            The OpenID to find the user for
 641          * @return The user connected with the given OpenID, or {@code null} if
 642          *         there is no such user
 643          * @throws DatabaseException
 644          *             if a database error occurs
 645          */
 646         public User getUserByOpenId(String openId) throws DatabaseException {
 647                 Query query = new Query(Type.SELECT, "USERS");
 648                 query.addField(new Field("USERS.*"));
 649                 query.addJoin(new Join(JoinType.INNER, "USER_OPENIDS", new Field("USER_OPENIDS.USER"), new Field("USERS.ID")));
 650                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USER_OPENIDS.OPENID", new StringParameter(openId))));
 651                 return database.getSingle(query, userCreator);
 652         }
 653
 654         /**
 655          * Returns all OpenIDs connected with the user with the given ID.
 656          *
 657          * @param userId
 658          *            The ID of the user
 659          * @return All OpenIDs connected with the given user
 660          * @throws DatabaseException
 661          *             if a database error occurs
 662          */
 663         public Collection<String> getOpenIdsByUser(String userId) throws DatabaseException {
 664                 Query query = new Query(Type.SELECT, "USER_OPENIDS");
 665                 query.addField(new Field("USER_OPENIDS.*"));
 666                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USER_OPENIDS.USER", new StringParameter(userId))));
 667                 return database.getMultiple(query, new StringCreator("USER_OPENIDS.OPENID"));
 668         }
 669
 670         //
 671         // PRIVATE METHODS
 672         //
 673
 674         /**
 675          * Loads the properties for the given object.
 676          *
 677          * @param <T>
 678          *            The type of the object
 679          * @param object
 680          *            The object
 681          * @param table
 682          *            The table to load the properties from
 683          * @param type
 684          *            The type of the object (“ARTIST,” “TRACK,” etc.)
 685          * @return The object with its properties loaded
 686          * @throws DatabaseException
 687          *             if a database error occurs
 688          */
 689         private <T extends Base> T loadProperties(final T object, final String table, String type) throws DatabaseException {
 690                 Query query = new Query(Type.SELECT, table);
 691                 query.addField(new Field(table + ".PROPERTY"));
 692                 query.addField(new Field(table + ".VALUE"));
 693                 query.addWhereClause(new ValueFieldWhereClause(new ValueField(type, new StringParameter(object.getId()))));
 694                 database.process(query, new ResultProcessor() {
 695
 696                         @Override
 697                         public void processResult(ResultSet resultSet) throws SQLException {
 698                                 if (resultSet.isFirst()) {
 699                                         object.getProperties().removeAll();
 700                                 }
 701                                 object.getProperties().set(resultSet.getString(table + ".PROPERTY"), resultSet.getString(table + ".VALUE"));
 702                         }
 703
 704                 });
 705                 return object;
 706         }
 707
 708         /**
 709          * {@link Artist} implementation that retrieves some attributes (such as
 710          * {@link #getGroups()}, and {@link #getTracks()}) from the
 711          * {@link DataManager} on demand.
 712          *
 713          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 714          */
 715         private class LazyArtist extends DefaultArtist {
 716
 717                 /** Memoizer for the tracks by this artist. */
 718                 private final Memoizer<Void> tracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
 719
 720                         @Override
 721                         public Void call() throws DatabaseException {
 722                                 if (!hasValue("tracks")) {
 723                                         getValue("tracks", Collection.class).set(getTracksByArtist(getId()));
 724                                 }
 725                                 return null;
 726                         }
 727                 });
 728
 729                 /** Memoizer for the groups of this artist. */
 730                 private final Memoizer<Void> groupsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 731
 732                         @Override
 733                         public Void call() throws Exception {
 734                                 if (!hasValue("groups")) {
 735                                         getValue("groups", Collection.class).set(getGroupsByArtist(getId()));
 736                                 }
 737                                 return null;
 738                         }
 739
 740                 });
 741
 742                 /**
 743                  * Creates a new lazy artist.
 744                  *
 745                  * @param id
 746                  *            The ID of the artist
 747                  */
 748                 public LazyArtist(String id) {
 749                         super(id);
 750                 }
 751
 752                 //
 753                 // DEFAULTARTIST METHODS
 754                 //
 755
 756                 /**
 757                  * {@inheritDoc}
 758                  */
 759                 @Override
 760                 public Collection<Group> getGroups() {
 761                         groupsMemoizer.get();
 762                         return super.getGroups();
 763                 }
 764
 765                 /**
 766                  * {@inheritDoc}
 767                  */
 768                 @Override
 769                 public Collection<Track> getTracks() {
 770                         tracksMemoizer.get();
 771                         return super.getTracks();
 772                 }
 773
 774         }
 775
 776         /**
 777          * {@link ObjectCreator} implementation that can create {@link Artist}
 778          * objects. This specific class actually creates {@link LazyArtist}
 779          * instances.
 780          *
 781          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 782          */
 783         private class ArtistCreator implements ObjectCreator<Artist> {
 784
 785                 /**
 786                  * {@inheritDoc}
 787                  */
 788                 @Override
 789                 public Artist createObject(ResultSet resultSet) throws SQLException {
 790                         return new LazyArtist(resultSet.getString("ARTISTS.ID")).setName(resultSet.getString("ARTISTS.NAME"));
 791                 }
 792
 793         }
 794
 795         /**
 796          * {@link Group} implementation that retrieves some attributes (such as
 797          * {@link #getArtists()}) from the {@link DataManager} on demand.
 798          *
 799          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 800          */
 801         private class LazyGroup extends DefaultGroup {
 802
 803                 /** Memoizer for the artist. */
 804                 private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 805
 806                         @Override
 807                         public Void call() throws Exception {
 808                                 if (!hasValue("artists")) {
 809                                         getValue("artists", Collection.class).set(getArtistsByGroup(getId()));
 810                                 }
 811                                 return null;
 812                         }
 813
 814                 });
 815
 816                 /**
 817                  * Creates a new lazy group.
 818                  *
 819                  * @param id
 820                  *            The ID of the group
 821                  */
 822                 public LazyGroup(String id) {
 823                         super(id);
 824                 }
 825
 826                 //
 827                 // DEFAULTGROUP METHODS
 828                 //
 829
 830                 /**
 831                  * {@inheritDoc}
 832                  */
 833                 @Override
 834                 public Collection<Artist> getArtists() {
 835                         artistsMemoizer.get();
 836                         return super.getArtists();
 837                 }
 838
 839         }
 840
 841         /**
 842          * {@link ObjectCreator} implementation that can create {@link Group}
 843          * objects. This specific implementation creates {@link LazyGroup}
 844          * instances.
 845          *
 846          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 847          */
 848         private class GroupCreator implements ObjectCreator<Group> {
 849
 850                 /**
 851                  * {@inheritDoc}
 852                  */
 853                 @Override
 854                 public Group createObject(ResultSet resultSet) throws SQLException {
 855                         return new LazyGroup(resultSet.getString("GROUPS.ID")).setName(resultSet.getString("GROUPS.NAME")).setUrl(resultSet.getString("GROUPS.URL"));
 856                 }
 857
 858         }
 859
 860         /**
 861          * {@link Track} implementation that retrieves some attributes (such as
 862          * {@link #getArtists()}, and {@link #getStyles()}) from the
 863          * {@link DataManager} on demand.
 864          *
 865          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 866          */
 867         private class LazyTrack extends DefaultTrack {
 868
 869                 /** Memoizer for the artists. */
 870                 private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 871
 872                         @Override
 873                         public Void call() throws Exception {
 874                                 if (!hasValue("artists")) {
 875                                         getValue("artists", List.class).set(getArtistsByTrack(getId()));
 876                                 }
 877                                 return null;
 878                         }
 879
 880                 });
 881
 882                 /** Memoizer for the styles. */
 883                 private final Memoizer<Void> stylesMemoizer = new Memoizer<Void>(new Callable<Void>() {
 884
 885                         @Override
 886                         public Void call() throws Exception {
 887                                 if (!hasValue("styles")) {
 888                                         getValue("styles", Collection.class).set(getStylesByTrack(getId()));
 889                                 }
 890                                 return null;
 891                         }
 892
 893                 });
 894
 895                 /** Memoizer for the remix artists. */
 896                 private final Memoizer<Void> remixArtistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 897
 898                         @Override
 899                         public Void call() throws Exception {
 900                                 if (!hasValue("remixArtists")) {
 901                                         getValue("remixArtists", List.class).set(getRemixArtistsByTrack(getId()));
 902                                 }
 903                                 return null;
 904                         }
 905
 906                 });
 907
 908                 /** Memoizer for the track derivatives. */
 909                 private final Memoizer<Void> derivativesMemoizer = new Memoizer<Void>(new Callable<Void>() {
 910
 911                         @Override
 912                         public Void call() throws Exception {
 913                                 if (!hasValue("derivatives")) {
 914                                         getValue("derivatives", Collection.class).set(getTrackDerivativesByTrack(getId()));
 915                                 }
 916                                 return null;
 917                         }
 918
 919                 });
 920
 921                 /** Memoizer for the related tracks. */
 922                 private final Memoizer<Void> relatedTracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
 923
 924                         @Override
 925                         public Void call() throws Exception {
 926                                 if (!hasValue("relatedTracks")) {
 927                                         getValue("relatedTracks", Map.class).set(getRelatedTracksByTrack(getId()));
 928                                 }
 929                                 return null;
 930                         }
 931
 932                 });
 933
 934                 /**
 935                  * Creates a new track.
 936                  *
 937                  * @param id
 938                  *            The ID of the track
 939                  */
 940                 public LazyTrack(String id) {
 941                         super(id);
 942                 }
 943
 944                 //
 945                 // DEFAULTTRACK METHODS
 946                 //
 947
 948                 /**
 949                  * {@inheritDoc}
 950                  */
 951                 @Override
 952                 public List<Artist> getArtists() {
 953                         artistsMemoizer.get();
 954                         return super.getArtists();
 955                 }
 956
 957                 /**
 958                  * {@inheritDoc}
 959                  */
 960                 @Override
 961                 public Collection<Style> getStyles() {
 962                         stylesMemoizer.get();
 963                         return super.getStyles();
 964                 }
 965
 966                 /**
 967                  * {@inheritDoc}
 968                  */
 969                 @Override
 970                 public List<Artist> getRemixArtists() {
 971                         remixArtistsMemoizer.get();
 972                         return super.getRemixArtists();
 973                 }
 974
 975                 /**
 976                  * {@inheritDoc}
 977                  */
 978                 @Override
 979                 public Collection<TrackDerivative> getDerivatives() {
 980                         derivativesMemoizer.get();
 981                         return super.getDerivatives();
 982                 }
 983
 984                 /**
 985                  * {@inheritDoc}
 986                  */
 987                 @Override
 988                 public Map<Relationship, Collection<Track>> getRelatedTracks() {
 989                         relatedTracksMemoizer.get();
 990                         return super.getRelatedTracks();
 991                 }
 992
 993         }
 994
 995         /**
 996          * {@link ObjectCreator} implementation that can create {@link Track}
 997          * objects. This specific implementation creates {@link LazyTrack}
 998          * instances.
 999          *
1000          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1001          */
1002         private class TrackCreator implements ObjectCreator<Track> {
1003
1004                 /**
1005                  * {@inheritDoc}
1006                  */
1007                 @Override
1008                 public Track createObject(ResultSet resultSet) throws SQLException {
1009                         return new LazyTrack(resultSet.getString("TRACKS.ID")).setName(resultSet.getString("TRACKS.NAME")).setRemix(resultSet.getString("TRACKS.REMIX"));
1010                 }
1011
1012         }
1013
1014         /**
1015          * {@link ObjectCreator} implementation that can create
1016          * {@link TrackDerivative} objects.
1017          *
1018          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1019          */
1020         private class TrackDerivativeCreator implements ObjectCreator<TrackDerivative> {
1021
1022                 /**
1023                  * {@inheritDoc}
1024                  */
1025                 @Override
1026                 public TrackDerivative createObject(ResultSet resultSet) throws SQLException {
1027                         return new DefaultTrackDerivative(resultSet.getString("TRACK_DERIVATIVES.ID"));
1028                 }
1029
1030         }
1031
1032         /**
1033          * {@link ObjectCreator} implementation that can create {@link Style}
1034          * objects.
1035          *
1036          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1037          */
1038         private class StyleCreator implements ObjectCreator<Style> {
1039
1040                 /**
1041                  * {@inheritDoc}
1042                  */
1043                 @Override
1044                 public Style createObject(ResultSet resultSet) throws SQLException {
1045                         return new DefaultStyle(resultSet.getString("STYLES.ID")).setName(resultSet.getString("STYLES.NAME"));
1046                 }
1047
1048         }
1049
1050         /**
1051          * {@link Party} implementation that loads additional information only on
1052          * demand.
1053          *
1054          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1055          */
1056         private class LazyParty extends DefaultParty {
1057
1058                 /**
1059                  * Creates a new party.
1060                  *
1061                  * @param id
1062                  *            The ID of the party
1063                  */
1064                 public LazyParty(String id) {
1065                         super(id);
1066                 }
1067
1068                 //
1069                 // PARTY METHODS
1070                 //
1071
1072                 /**
1073                  * {@inheritDoc}
1074                  */
1075                 @Override
1076                 public Collection<Track> getReleases() {
1077                         if (!hasValue("releases")) {
1078                                 try {
1079                                         getValue("releases", Collection.class).set(getTracksByParty(getId()));
1080                                 } catch (DatabaseException de1) {
1081                                         throw new RuntimeException("Could not loaded Tracks for Party " + getId() + ".", de1);
1082                                 }
1083                         }
1084                         return super.getReleases();
1085                 }
1086
1087         }
1088
1089         /**
1090          * {@link ObjectCreator} implementation that can create {@link Party}
1091          * objects.
1092          *
1093          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1094          */
1095         private class PartyCreator implements ObjectCreator<Party> {
1096
1097                 /**
1098                  * {@inheritDoc}
1099                  */
1100                 @Override
1101                 public Party createObject(ResultSet resultSet) throws SQLException {
1102                         return new LazyParty(resultSet.getString("PARTIES.ID")).setName(resultSet.getString("PARTIES.NAME"));
1103                 }
1104
1105         }
1106
1107         /**
1108          * {@link User} implementation that retrieves some attributes (such as
1109          * {@link #getOpenIds()}) from the {@link DataManager} on demand.
1110          *
1111          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1112          */
1113         private class LazyUser extends DefaultUser {
1114
1115                 /** Memoizer for a user’s OpenIDs. */
1116                 private final Memoizer<Void> openIdMemoizer = new Memoizer<Void>(new Callable<Void>() {
1117
1118                         @Override
1119                         public Void call() throws Exception {
1120                                 if (!hasValue("openIds")) {
1121                                         getValue("openIds", Collection.class).set(getOpenIdsByUser(getId()));
1122                                 }
1123                                 return null;
1124                         }
1125                 });
1126
1127                 /**
1128                  * Creates a new user.
1129                  *
1130                  * @param id
1131                  *            The ID of the user
1132                  */
1133                 public LazyUser(String id) {
1134                         super(id);
1135                 }
1136
1137                 /**
1138                  * {@inheritDoc}
1139                  */
1140                 @Override
1141                 public Collection<String> getOpenIds() {
1142                         openIdMemoizer.get();
1143                         return super.getOpenIds();
1144                 }
1145
1146         }
1147
1148         /**
1149          * {@link ObjectCreator} implementation that can create {@link User}
1150          * objects. This specific implementation creates {@link LazyUser} instances.
1151          *
1152          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1153          */
1154         private class UserCreator implements ObjectCreator<User> {
1155
1156                 /**
1157                  * {@inheritDoc}
1158                  */
1159                 @Override
1160                 public User createObject(ResultSet resultSet) throws SQLException {
1161                         return new LazyUser(resultSet.getString("USERS.ID")).setName(resultSet.getString("USERS.NAME")).setPasswordHash(resultSet.getString("USERS.PASSWORD")).setLevel(resultSet.getInt("USERS.LEVEL"));
1162                 }
1163
1164         }
1165
1166 }