001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.io;
003
004import static org.openstreetmap.josm.tools.I18n.tr;
005
006import java.io.InputStream;
007import java.text.MessageFormat;
008import java.util.ArrayList;
009import java.util.Collection;
010
011import org.openstreetmap.josm.data.osm.DataSet;
012import org.openstreetmap.josm.data.osm.DataSetMerger;
013import org.openstreetmap.josm.data.osm.OsmPrimitive;
014import org.openstreetmap.josm.data.osm.OsmPrimitiveType;
015import org.openstreetmap.josm.data.osm.Relation;
016import org.openstreetmap.josm.data.osm.Way;
017import org.openstreetmap.josm.gui.progress.NullProgressMonitor;
018import org.openstreetmap.josm.gui.progress.ProgressMonitor;
019import org.openstreetmap.josm.tools.CheckParameterUtil;
020
021/**
022 * OsmServerBackreferenceReader fetches the primitives from the OSM server which
023 * refer to a specific primitive. For a {@link org.openstreetmap.josm.data.osm.Node Node}, ways and relations are retrieved
024 * which refer to the node. For a {@link Way} or a {@link Relation}, only relations are read.
025 *
026 * OsmServerBackreferenceReader uses the API calls <code>[node|way|relation]/#id/relations</code>
027 * and  <code>node/#id/ways</code> to retrieve the referring primitives. The default behaviour
028 * of these calls is to reply incomplete primitives only.
029 *
030 * If you set {@link #setReadFull(boolean)} to true this reader uses a {@link MultiFetchServerObjectReader}
031 * to complete incomplete primitives.
032 *
033 * @since 1806
034 */
035public class OsmServerBackreferenceReader extends OsmServerReader {
036
037    /** the id of the primitive whose referrers are to be read */
038    private long id;
039    /** the type of the primitive */
040    private OsmPrimitiveType primitiveType;
041    /** true if this reader should complete incomplete primitives */
042    private boolean readFull;
043
044    /**
045     * constructor
046     *
047     * @param primitive  the primitive to be read. Must not be null. primitive.id &gt; 0 expected
048     *
049     * @throws IllegalArgumentException if primitive is null
050     * @throws IllegalArgumentException if primitive.id &lt;= 0
051     */
052    public OsmServerBackreferenceReader(OsmPrimitive primitive) {
053        CheckParameterUtil.ensureValidPrimitiveId(primitive, "primitive");
054        this.id = primitive.getId();
055        this.primitiveType = OsmPrimitiveType.from(primitive);
056        this.readFull = false;
057    }
058
059    /**
060     * constructor
061     *
062     * @param id  the id of the primitive. &gt; 0 expected
063     * @param type the type of the primitive. Must not be null.
064     *
065     * @throws IllegalArgumentException if id &lt;= 0
066     * @throws IllegalArgumentException if type is null
067     */
068    public OsmServerBackreferenceReader(long id, OsmPrimitiveType type) {
069        if (id <= 0)
070            throw new IllegalArgumentException(MessageFormat.format("Parameter ''{0}'' > 0 expected. Got ''{1}''.", "id", id));
071        CheckParameterUtil.ensureParameterNotNull(type, "type");
072        this.id = id;
073        this.primitiveType = type;
074        this.readFull = false;
075    }
076
077    /**
078     * Creates a back reference reader for given primitive
079     *
080     * @param primitive the primitive
081     * @param readFull <code>true</code>, if referers should be read fully (i.e. including their immediate children)
082     *
083     */
084    public OsmServerBackreferenceReader(OsmPrimitive primitive, boolean readFull) {
085        this(primitive);
086        this.readFull = readFull;
087    }
088
089    /**
090     * Creates a back reference reader for given primitive id
091     *
092     * @param id the id of the primitive whose referers are to be read
093     * @param type the type of the primitive
094     * @param readFull true, if referers should be read fully (i.e. including their immediate children)
095     *
096     * @throws IllegalArgumentException if id &lt;= 0
097     * @throws IllegalArgumentException if type is null
098     */
099    public OsmServerBackreferenceReader(long id, OsmPrimitiveType type, boolean readFull)  {
100        this(id, type);
101        this.readFull = readFull;
102    }
103
104    /**
105     * Replies true if this reader also reads immediate children of referring primitives
106     *
107     * @return true if this reader also reads immediate children of referring primitives
108     */
109    public boolean isReadFull() {
110        return readFull;
111    }
112
113    /**
114     * Set true if this reader should reads immediate children of referring primitives too. False, otherweise.
115     *
116     * @param readFull true if this reader should reads immediate children of referring primitives too. False, otherweise.
117     */
118    public void setReadFull(boolean readFull) {
119        this.readFull = readFull;
120    }
121
122    private DataSet getReferringPrimitives(ProgressMonitor progressMonitor, String type, String message) throws OsmTransferException {
123        progressMonitor.beginTask(null, 2);
124        try {
125            progressMonitor.subTask(tr("Contacting OSM Server..."));
126            StringBuilder sb = new StringBuilder();
127            sb.append(primitiveType.getAPIName()).append('/').append(id).append(type);
128
129            try (InputStream in = getInputStream(sb.toString(), progressMonitor.createSubTaskMonitor(1, true))) {
130                if (in == null)
131                    return null;
132                progressMonitor.subTask(message);
133                return OsmReader.parseDataSet(in, progressMonitor.createSubTaskMonitor(1, true));
134            }
135        } catch (OsmTransferException e) {
136            throw e;
137        } catch (Exception e) {
138            if (cancel)
139                return null;
140            throw new OsmTransferException(e);
141        } finally {
142            progressMonitor.finishTask();
143            activeConnection = null;
144        }
145    }
146
147    /**
148     * Reads referring ways from the API server and replies them in a {@link DataSet}
149     *
150     * @return the data set
151     * @throws OsmTransferException if any error occurs during dialog with OSM API
152     */
153    protected DataSet getReferringWays(ProgressMonitor progressMonitor) throws OsmTransferException {
154        return getReferringPrimitives(progressMonitor, "/ways", tr("Downloading referring ways ..."));
155    }
156
157    /**
158     * Reads referring relations from the API server and replies them in a {@link DataSet}
159     *
160     * @param progressMonitor the progress monitor
161     * @return the data set
162     * @throws OsmTransferException if any error occurs during dialog with OSM API
163     */
164    protected DataSet getReferringRelations(ProgressMonitor progressMonitor) throws OsmTransferException {
165        return getReferringPrimitives(progressMonitor, "/relations", tr("Downloading referring relations ..."));
166    }
167
168    /**
169     * Scans a dataset for incomplete primitives. Depending on the configuration of this reader
170     * incomplete primitives are read from the server with an individual <tt>/api/0.6/[way,relation]/#id/full</tt>
171     * request.
172     *
173     * <ul>
174     *   <li>if this reader reads referers for a {@link org.openstreetmap.josm.data.osm.Node}, referring ways are always
175     *     read individually from the server</li>
176     *   <li>if this reader reads referers for an {@link Way} or a {@link Relation}, referring relations
177     *    are only read fully if {@link #setReadFull(boolean)} is set to true.</li>
178     * </ul>
179     *
180     * The method replies the modified dataset.
181     *
182     * @param ds the original dataset
183     * @param progressMonitor  the progress monitor
184     * @return the modified dataset
185     * @throws OsmTransferException if an exception occurs.
186     */
187    protected DataSet readIncompletePrimitives(DataSet ds, ProgressMonitor progressMonitor) throws OsmTransferException {
188        progressMonitor.beginTask(null, 2);
189        try {
190            Collection<Way> waysToCheck = new ArrayList<>(ds.getWays());
191            if (isReadFull() || primitiveType.equals(OsmPrimitiveType.NODE)) {
192                for (Way way: waysToCheck) {
193                    if (!way.isNew() && way.hasIncompleteNodes()) {
194                        OsmServerObjectReader reader = new OsmServerObjectReader(way.getId(), OsmPrimitiveType.from(way), true /* read full */);
195                        DataSet wayDs = reader.parseOsm(progressMonitor.createSubTaskMonitor(1, false));
196                        DataSetMerger visitor = new DataSetMerger(ds, wayDs);
197                        visitor.merge();
198                    }
199                }
200            }
201            if (isReadFull()) {
202                Collection<Relation> relationsToCheck  = new ArrayList<>(ds.getRelations());
203                for (Relation relation: relationsToCheck) {
204                    if (!relation.isNew() && relation.hasIncompleteMembers()) {
205                        OsmServerObjectReader reader = new OsmServerObjectReader(relation.getId(), OsmPrimitiveType.from(relation), true);
206                        DataSet wayDs = reader.parseOsm(progressMonitor.createSubTaskMonitor(1, false));
207                        DataSetMerger visitor = new DataSetMerger(ds, wayDs);
208                        visitor.merge();
209                    }
210                }
211            }
212            return ds;
213        } finally {
214            progressMonitor.finishTask();
215        }
216    }
217
218    /**
219     * Reads the referring primitives from the OSM server, parses them and
220     * replies them as {@link DataSet}
221     *
222     * @param progressMonitor the progress monitor. Set to {@link NullProgressMonitor#INSTANCE} if null.
223     * @return the dataset with the referring primitives
224     * @throws OsmTransferException if an error occurs while communicating with the server
225     */
226    @Override
227    public DataSet parseOsm(ProgressMonitor progressMonitor) throws OsmTransferException {
228        if (progressMonitor == null) {
229            progressMonitor = NullProgressMonitor.INSTANCE;
230        }
231        try {
232            progressMonitor.beginTask(null, 3);
233            DataSet ret = new DataSet();
234            if (primitiveType.equals(OsmPrimitiveType.NODE)) {
235                DataSet ds = getReferringWays(progressMonitor.createSubTaskMonitor(1, false));
236                DataSetMerger visitor = new DataSetMerger(ret, ds);
237                visitor.merge();
238                ret = visitor.getTargetDataSet();
239            }
240            DataSet ds = getReferringRelations(progressMonitor.createSubTaskMonitor(1, false));
241            DataSetMerger visitor = new DataSetMerger(ret, ds);
242            visitor.merge();
243            ret = visitor.getTargetDataSet();
244            if (ret != null) {
245                readIncompletePrimitives(ret, progressMonitor.createSubTaskMonitor(1, false));
246                ret.deleteInvisible();
247            }
248            return ret;
249        } finally {
250            progressMonitor.finishTask();
251        }
252    }
253}