package com.onthegomap.planetiler.reader.osm;

import static com.onthegomap.planetiler.util.MemoryEstimator.estimateSize;
import static com.onthegomap.planetiler.worker.Worker.joinFutures;

import com.carrotsearch.hppc.IntObjectHashMap;
import com.carrotsearch.hppc.LongArrayList;
import com.carrotsearch.hppc.LongHashSet;
import com.carrotsearch.hppc.LongObjectHashMap;
import com.carrotsearch.hppc.ObjectIntHashMap;
import com.onthegomap.planetiler.FeatureCollector;
import com.onthegomap.planetiler.Profile;
import com.onthegomap.planetiler.collection.FeatureGroup;
import com.onthegomap.planetiler.collection.Hppc;
import com.onthegomap.planetiler.collection.LongLongMap;
import com.onthegomap.planetiler.collection.LongLongMultimap;
import com.onthegomap.planetiler.collection.SortableFeature;
import com.onthegomap.planetiler.config.PlanetilerConfig;
import com.onthegomap.planetiler.geo.GeoUtils;
import com.onthegomap.planetiler.geo.GeometryException;
import com.onthegomap.planetiler.reader.SourceFeature;
import com.onthegomap.planetiler.render.FeatureRenderer;
import com.onthegomap.planetiler.stats.Counter;
import com.onthegomap.planetiler.stats.ProcessInfo;
import com.onthegomap.planetiler.stats.ProgressLoggers;
import com.onthegomap.planetiler.stats.Stats;
import com.onthegomap.planetiler.util.Format;
import com.onthegomap.planetiler.util.MemoryEstimator;
import com.onthegomap.planetiler.worker.Distributor;
import com.onthegomap.planetiler.worker.WeightedHandoffQueue;
import com.onthegomap.planetiler.worker.WorkQueue;
import com.onthegomap.planetiler.worker.WorkerPipeline;
import java.io.Closeable;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicLong;
import java.util.function.Consumer;
import java.util.function.Supplier;
import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.CoordinateList;
import org.locationtech.jts.geom.CoordinateSequence;
import org.locationtech.jts.geom.CoordinateXY;
import org.locationtech.jts.geom.Geometry;
import org.locationtech.jts.geom.LineString;
import org.locationtech.jts.geom.MultiPolygon;
import org.locationtech.jts.geom.Point;
import org.locationtech.jts.geom.Polygon;
import org.locationtech.jts.geom.impl.CoordinateArraySequence;
import org.locationtech.jts.geom.impl.PackedCoordinateSequence;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Utility that constructs {@link SourceFeature SourceFeatures} from the raw nodes, ways, and relations contained in an
 * {@link OsmInputFile}.
 */
public class OsmReader implements Closeable, MemoryEstimator.HasEstimate {

  private static final Logger LOGGER = LoggerFactory.getLogger(OsmReader.class);
  private static final Format FORMAT = Format.defaultInstance();
  private static final int ROLE_BITS = 16;
  private static final int MAX_ROLES = (1 << ROLE_BITS) - 10;
  private static final int ROLE_SHIFT = 64 - ROLE_BITS;
  private static final int ROLE_MASK = (1 << ROLE_BITS) - 1;
  private static final long NOT_ROLE_MASK = (1L << ROLE_SHIFT) - 1L;
  private final OsmBlockSource osmBlockSource;
  private final Stats stats;
  private final LongLongMap nodeLocationDb;
  private final Counter.Readable PASS1_BLOCKS = Counter.newSingleThreadCounter();
  private final Counter.Readable PASS1_NODES = Counter.newSingleThreadCounter();
  private final Counter.Readable PASS1_WAYS = Counter.newSingleThreadCounter();
  private final Counter.Readable PASS1_RELATIONS = Counter.newSingleThreadCounter();
  private final Profile profile;
  private final String name;
  private final AtomicLong relationInfoSizes = new AtomicLong(0);
  // need a few large objects to process ways in relations, should be small enough to keep in memory
  // for routes (750k rels 40m ways) and boundaries (650k rels, 8m ways)
  // need to store route info to use later when processing ways
  // <~500mb
  private LongObjectHashMap<OsmRelationInfo> relationInfo = Hppc.newLongObjectHashMap();
  // ~800mb, ~1.6GB when sorting
  private LongLongMultimap wayToRelations = LongLongMultimap.newSparseUnorderedMultimap();
  // for multipolygons need to store way info (20m ways, 800m nodes) to use when processing relations (4.5m)
  // ~300mb
  private LongHashSet waysInMultipolygon = new LongHashSet();
  // ~7GB
  private LongLongMultimap multipolygonWayGeometries = LongLongMultimap.newDensedOrderedMultimap();
  // keep track of data needed to encode/decode role strings into a long
  private final ObjectIntHashMap<String> roleIds = new ObjectIntHashMap<>();
  private final IntObjectHashMap<String> roleIdsReverse = new IntObjectHashMap<>();
  private final AtomicLong roleSizes = new AtomicLong(0);

  /**
   * Constructs a new {@code OsmReader} from
   *
   * @param name              ID for this reader to use in stats and logs
   * @param osmSourceProvider the file to read raw nodes, ways, and relations from
   * @param nodeLocationDb    store that will temporarily hold node locations (encoded as a long) between passes to
   *                          reconstruct way geometries
   * @param profile           logic that defines what map features to emit for each source feature
   * @param stats             to keep track of counters and timings
   */
  public OsmReader(String name, Supplier<OsmBlockSource> osmSourceProvider, LongLongMap nodeLocationDb, Profile profile,
    Stats stats) {
    this.name = name;
    this.osmBlockSource = osmSourceProvider.get();
    this.nodeLocationDb = nodeLocationDb;
    this.stats = stats;
    this.profile = profile;
    stats.monitorInMemoryObject("osm_relations", this);
    stats.counter("osm_pass1_elements_processed", "type", () -> Map.of(
      "blocks", PASS1_BLOCKS,
      "nodes", PASS1_NODES,
      "ways", PASS1_WAYS,
      "relations", PASS1_RELATIONS
    ));
  }

  /**
   * Pre-processes all OSM elements before {@link #pass2(FeatureGroup, PlanetilerConfig)} is used to emit map features.
   * <p>
   * Stores node locations for pass2 to use to reconstruct way geometries.
   * <p>
   * Also stores the result of {@link Profile#preprocessOsmRelation(OsmElement.Relation)} so that pass2 can know the
   * relevant relations that a way belongs to.
   *
   * @param config user-provided arguments to control the number of threads, and log interval
   */
  public void pass1(PlanetilerConfig config) {
    record BlockWithResult(OsmBlockSource.Block block, WeightedHandoffQueue<OsmElement> result) {}
    var timer = stats.startStage("osm_pass1");
    int parseThreads = Math.max(1, config.threads() - 2);
    int pendingBlocks = parseThreads * 2;
    // Each worker will hand off finished elements to the single process thread. A Future<List<OsmElement>> would result
    // in too much memory usage/GC so use a WeightedHandoffQueue instead which will fill up with lightweight objects
    // like nodes without any tags, but limit the number of pending heavy entities like relations
    int handoffQueueBatches = Math.max(
      10,
      (int) (100d * ProcessInfo.getMaxMemoryBytes() / 100_000_000_000d)
    );
    var parsedBatches = new WorkQueue<WeightedHandoffQueue<OsmElement>>("elements", pendingBlocks, 1, stats);
    var pipeline = WorkerPipeline.start("osm_pass1", stats);
    var readBranch = pipeline
      .<BlockWithResult>fromGenerator("read", next -> {
        osmBlockSource.forEachBlock((block) -> {
          WeightedHandoffQueue<OsmElement> result = new WeightedHandoffQueue<>(handoffQueueBatches, 10_000);
          parsedBatches.accept(result);
          next.accept(new BlockWithResult(block, result));
        });
        parsedBatches.close();
      })
      .addBuffer("pbf_blocks", pendingBlocks)
      .sinkToConsumer("parse", parseThreads, block -> {
        List<OsmElement> result = new ArrayList<>();
        boolean nodesDone = false, waysDone = false;
        for (var element : block.block.decodeElements()) {
          if (element instanceof OsmElement.Node node) {
            // pre-compute encoded location in worker threads since it is fairly expensive and should be done in parallel
            node.encodedLocation();
            if (nodesDone) {
              throw new IllegalArgumentException(
                "Input file must be sorted with nodes first, then ways, then relations. Encountered node " + node.id() +
                  " after a way or relation");
            }
          } else if (element instanceof OsmElement.Way way) {
            nodesDone = true;
            if (waysDone) {
              throw new IllegalArgumentException(
                "Input file must be sorted with nodes first, then ways, then relations. Encountered way " + way.id() +
                  " after a relation");
            }
          } else if (element instanceof OsmElement.Relation) {
            nodesDone = waysDone = true;
          }
          block.result.accept(element, element.cost());
        }
        block.result.close();
      });

    var processBranch = pipeline
      .readFromQueue(parsedBatches)
      .sinkToConsumer("process", 1, this::processPass1Block);

    var loggers = ProgressLoggers.create()
      .addRateCounter("nodes", PASS1_NODES, true)
      .addFileSizeAndRam(nodeLocationDb)
      .addRateCounter("ways", PASS1_WAYS, true)
      .addRateCounter("rels", PASS1_RELATIONS, true)
      .addRateCounter("blocks", PASS1_BLOCKS)
      .newLine()
      .addProcessStats()
      .addInMemoryObject("hppc", this)
      .newLine()
      .addPipelineStats(readBranch)
      .addPipelineStats(processBranch);

    loggers.awaitAndLog(joinFutures(readBranch.done(), processBranch.done()), config.logInterval());

    LOGGER.debug("processed " +
      "blocks:" + FORMAT.integer(PASS1_BLOCKS.get()) +
      " nodes:" + FORMAT.integer(PASS1_NODES.get()) +
      " ways:" + FORMAT.integer(PASS1_WAYS.get()) +
      " relations:" + FORMAT.integer(PASS1_RELATIONS.get()));
    timer.stop();
  }

  void processPass1Block(Iterable<? extends OsmElement> elements) {
    int nodes = 0, ways = 0, relations = 0;
    for (OsmElement element : elements) {
      // only a single thread calls this with elements ordered by ID, so it's safe to manipulate these
      // shared data structures which are not thread safe
      if (element.id() < 0) {
        throw new IllegalArgumentException("Negative OSM element IDs not supported: " + element);
      }
      if (element instanceof OsmElement.Node node) {
        nodes++;
        try {
          profile.preprocessOsmNode(node);
        } catch (Exception e) {
          LOGGER.error("Error preprocessing OSM node " + node.id(), e);
        }
        // TODO allow limiting node storage to only ones that profile cares about
        nodeLocationDb.put(node.id(), node.encodedLocation());
      } else if (element instanceof OsmElement.Way way) {
        ways++;
        try {
          profile.preprocessOsmWay(way);
        } catch (Exception e) {
          LOGGER.error("Error preprocessing OSM way " + way.id(), e);
        }
      } else if (element instanceof OsmElement.Relation relation) {
        relations++;
        try {
          List<OsmRelationInfo> infos = profile.preprocessOsmRelation(relation);
          if (infos != null) {
            for (OsmRelationInfo info : infos) {
              relationInfo.put(relation.id(), info);
              relationInfoSizes.addAndGet(info.estimateMemoryUsageBytes());
              for (var member : relation.members()) {
                var type = member.type();
                // TODO handle nodes in relations and super-relations
                if (type == OsmElement.Type.WAY) {
                  wayToRelations.put(member.ref(), encodeRelationMembership(member.role(), relation.id()));
                }
              }
            }
          }
        } catch (Exception e) {
          LOGGER.error("Error preprocessing OSM relation " + relation.id(), e);
        }
        // TODO allow limiting multipolygon storage to only ones that profile cares about
        if (isMultipolygon(relation)) {
          for (var member : relation.members()) {
            if (member.type() == OsmElement.Type.WAY) {
              waysInMultipolygon.add(member.ref());
            }
          }
        }
      }
    }
    PASS1_BLOCKS.inc();
    PASS1_NODES.incBy(nodes);
    PASS1_WAYS.incBy(ways);
    PASS1_RELATIONS.incBy(relations);
  }

  private static boolean isMultipolygon(OsmElement.Relation relation) {
    return relation.hasTag("type", "multipolygon", "boundary", "land_area");
  }

  /**
   * Constructs geometries from OSM elements and emits map features as defined by the {@link Profile}.
   *
   * @param writer consumer that will store finished features
   * @param config user-provided arguments to control the number of threads, and log interval
   */
  public void pass2(FeatureGroup writer, PlanetilerConfig config) {
    var timer = stats.startStage("osm_pass2");
    int threads = config.threads();
    int processThreads = Math.max(threads < 4 ? threads : (threads - 1), 1);
    Counter.MultiThreadCounter blocksProcessed = Counter.newMultiThreadCounter();
    Counter.MultiThreadCounter nodesProcessed = Counter.newMultiThreadCounter();
    Counter.MultiThreadCounter waysProcessed = Counter.newMultiThreadCounter();
    Counter.MultiThreadCounter relsProcessed = Counter.newMultiThreadCounter();
    stats.counter("osm_pass2_elements_processed", "type", () -> Map.of(
      "blocks", blocksProcessed,
      "nodes", nodesProcessed,
      "ways", waysProcessed,
      "relations", relsProcessed
    ));

    // since multiple threads process OSM elements, and we must process all ways before processing any relations,
    // use a count down latch to wait for all threads to finish processing ways
    CountDownLatch waitForWays = new CountDownLatch(processThreads);
    // Use a Distributor to keep all worker threads busy when processing the final blocks of relations by offloading
    // items to threads that are done reading blocks
    Distributor<OsmElement.Relation> relationDistributor = Distributor.createWithCapacity(1_000);

    var pipeline = WorkerPipeline.start("osm_pass2", stats)
      .fromGenerator("read", osmBlockSource::forEachBlock)
      .addBuffer("pbf_blocks", 100)
      .<SortableFeature>addWorker("process", processThreads, (prev, next) -> {
        // avoid contention trying to get the thread-local counters by getting them once when thread starts
        Counter blocks = blocksProcessed.counterForThread();
        Counter nodes = nodesProcessed.counterForThread();
        Counter ways = waysProcessed.counterForThread();
        Counter rels = relsProcessed.counterForThread();

        var waysDone = false;
        var featureCollectors = new FeatureCollector.Factory(config, stats);
        final NodeLocationProvider nodeLocations = newNodeLocationProvider();
        FeatureRenderer renderer = createFeatureRenderer(writer, config, next);
        var relationHandler = relationDistributor.forThread(relation -> {
          var feature = processRelationPass2(relation, nodeLocations);
          if (feature != null) {
            render(featureCollectors, renderer, relation, feature);
          }
          rels.inc();
        });

        for (var block : prev) {
          int blockNodes = 0, blockWays = 0;
          for (var element : block.decodeElements()) {
            SourceFeature feature = null;
            if (element instanceof OsmElement.Node node) {
              blockNodes++;
              feature = processNodePass2(node);
            } else if (element instanceof OsmElement.Way way) {
              blockWays++;
              feature = processWayPass2(way, nodeLocations);
            } else if (element instanceof OsmElement.Relation relation) {
              // ensure all ways finished processing before we start relations
              if (!waysDone && waitForWays.getCount() > 0) {
                waitForWays.countDown();
                waitForWays.await();
                waysDone = true;
              }
              relationHandler.accept(relation);
            }
            // render features specified by profile and hand them off to next step that will
            // write them intermediate storage
            if (feature != null) {
              render(featureCollectors, renderer, element, feature);
            }
          }

          blocks.inc();
          nodes.incBy(blockNodes);
          ways.incBy(blockWays);
        }
        // just in case a worker skipped over all relations
        waitForWays.countDown();

        // do work for other threads that are still processing blocks of relations
        relationHandler.close();
      }).addBuffer("feature_queue", 50_000, 1_000)
      // FeatureGroup writes need to be single-threaded
      .sinkToConsumer("write", 1, writer);

    var logger = ProgressLoggers.create()
      .addRatePercentCounter("nodes", PASS1_NODES.get(), nodesProcessed, true)
      .addFileSizeAndRam(nodeLocationDb)
      .addRatePercentCounter("ways", PASS1_WAYS.get(), waysProcessed, true)
      .addRatePercentCounter("rels", PASS1_RELATIONS.get(), relsProcessed, true)
      .addRateCounter("features", writer::numFeaturesWritten)
      .addFileSize(writer)
      .addRatePercentCounter("blocks", PASS1_BLOCKS.get(), blocksProcessed, false)
      .newLine()
      .addProcessStats()
      .addInMemoryObject("hppc", this)
      .newLine()
      .addPipelineStats(pipeline);

    pipeline.awaitAndLog(logger, config.logInterval());

    LOGGER.debug("processed " +
      "blocks:" + FORMAT.integer(blocksProcessed.get()) +
      " nodes:" + FORMAT.integer(nodesProcessed.get()) +
      " ways:" + FORMAT.integer(waysProcessed.get()) +
      " relations:" + FORMAT.integer(relsProcessed.get()));

    timer.stop();

    try {
      profile.finish(name,
        new FeatureCollector.Factory(config, stats),
        createFeatureRenderer(writer, config, writer));
    } catch (Exception e) {
      LOGGER.error("Error calling profile.finish", e);
    }
  }

  private void render(FeatureCollector.Factory featureCollectors, FeatureRenderer renderer, OsmElement element,
    SourceFeature feature) {
    FeatureCollector features = featureCollectors.get(feature);
    try {
      profile.processFeature(feature, features);
      for (FeatureCollector.Feature renderable : features) {
        renderer.accept(renderable);
      }
    } catch (Exception e) {
      String type = element.getClass().getSimpleName();
      LOGGER.error("Error processing OSM " + type + " " + element.id(), e);
    }
  }

  private FeatureRenderer createFeatureRenderer(FeatureGroup writer, PlanetilerConfig config,
    Consumer<SortableFeature> next) {
    var encoder = writer.newRenderedFeatureEncoder();
    return new FeatureRenderer(
      config,
      rendered -> next.accept(encoder.apply(rendered)),
      stats
    );
  }

  SourceFeature processNodePass2(OsmElement.Node node) {
    // nodes are simple because they already contain their location
    return new NodeSourceFeature(node);
  }

  SourceFeature processWayPass2(OsmElement.Way way, NodeLocationProvider nodeLocations) {
    // ways contain an ordered list of node IDs, so we need to join that with node locations
    // from pass1 to reconstruct the geometry.
    LongArrayList nodes = way.nodes();
    if (waysInMultipolygon.contains(way.id())) {
      // if this is part of a multipolygon, store the node IDs for this way ID so that when
      // we get to the multipolygon we can go from way IDs -> node IDs -> node locations.
      synchronized (this) { // multiple threads may update this concurrently
        multipolygonWayGeometries.putAll(way.id(), nodes);
      }
    }
    boolean closed = nodes.size() > 1 && nodes.get(0) == nodes.get(nodes.size() - 1);
    // area tag used to differentiate between whether a closed way should be treated as a polygon or linestring
    String area = way.getString("area");
    List<RelationMember<OsmRelationInfo>> rels = getRelationMembershipForWay(way.id());
    return new WaySourceFeature(way, closed, area, nodeLocations, rels);
  }

  SourceFeature processRelationPass2(OsmElement.Relation rel, NodeLocationProvider nodeLocations) {
    // Relation info gets used during way processing, except multipolygons which we have to process after we've
    // stored all the node IDs for each way.
    if (isMultipolygon(rel)) {
      List<RelationMember<OsmRelationInfo>> parentRelations = getRelationMembershipForWay(rel.id());
      return new MultipolygonSourceFeature(rel, nodeLocations, parentRelations);
    } else {
      return null;
    }
  }

  private List<RelationMember<OsmRelationInfo>> getRelationMembershipForWay(long wayId) {
    LongArrayList relationIds = wayToRelations.get(wayId);
    List<RelationMember<OsmRelationInfo>> rels = null;
    if (!relationIds.isEmpty()) {
      rels = new ArrayList<>(relationIds.size());
      for (int r = 0; r < relationIds.size(); r++) {
        long encoded = relationIds.get(r);
        // encoded ID uses the upper few bits of the long to encode the role
        RelationMembership parsed = decodeRelationMembership(encoded);
        OsmRelationInfo rel = relationInfo.get(parsed.relationId);
        if (rel != null) {
          rels.add(new RelationMember<>(parsed.role, rel));
        }
      }
    }
    return rels;
  }

  @Override
  public long estimateMemoryUsageBytes() {
    long size = 0;
    size += estimateSize(waysInMultipolygon);
    size += estimateSize(multipolygonWayGeometries);
    size += estimateSize(wayToRelations);
    size += estimateSize(relationInfo);
    size += estimateSize(roleIdsReverse);
    size += estimateSize(roleIds);
    size += roleSizes.get();
    size += relationInfoSizes.get();
    return size;
  }

  @Override
  public void close() throws IOException {
    multipolygonWayGeometries = null;
    wayToRelations = null;
    waysInMultipolygon = null;
    relationInfo = null;
    nodeLocationDb.close();
    roleIds.release();
    roleIdsReverse.release();
    osmBlockSource.close();
  }

  NodeLocationProvider newNodeLocationProvider() {
    return new NodeDbLocationProvider();
  }

  public interface NodeLocationProvider {

    default CoordinateSequence getWayGeometry(LongArrayList nodeIds) {
      CoordinateList coordList = new CoordinateList();
      for (var cursor : nodeIds) {
        coordList.add(getCoordinate(cursor.value));
      }
      return new CoordinateArraySequence(coordList.toCoordinateArray());
    }

    Coordinate getCoordinate(long id);
  }

  /**
   * Member of a relation extracted from OSM input data.
   *
   * @param <T>      type of the user-defined class storing information about the relation
   * @param role     "role" of the relation member
   * @param relation user-provided data about the relation from pass1
   */
  public record RelationMember<T extends OsmRelationInfo> (String role, T relation) {}

  /** Raw relation membership data that gets encoded/decoded into a long. */
  private record RelationMembership(String role, long relationId) {}

  /** Returns the role and relation ID packed into a long. */
  private RelationMembership decodeRelationMembership(long encoded) {
    int role = (int) ((encoded >>> ROLE_SHIFT) & ROLE_MASK);
    return new RelationMembership(roleIdsReverse.get(role), encoded & NOT_ROLE_MASK);
  }

  /** Packs a string role and relation into a compact long for storage. */
  private long encodeRelationMembership(String role, long relationId) {
    int roleId = roleIds.getOrDefault(role, -1);
    if (roleId == -1) {
      roleSizes.addAndGet(estimateSize(role));
      roleId = roleIds.size() + 1;
      roleIds.put(role, roleId);
      roleIdsReverse.put(roleId, role);
      if (roleId > MAX_ROLES) {
        throw new IllegalStateException("Too many roles to encode: " + role);
      }
    }
    return relationId | ((long) roleId << ROLE_SHIFT);
  }

  /**
   * A source feature generated from OSM elements. Inferring the geometry can be expensive, so each sublass is
   * constructed with the inputs necessary to create the geometry, but the geometry is constructed lazily on read.
   */
  private abstract class OsmFeature extends SourceFeature {

    private final boolean polygon;
    private final boolean line;
    private final boolean point;
    private Geometry latLonGeom;
    private Geometry worldGeom;

    public OsmFeature(OsmElement elem, boolean point, boolean line, boolean polygon,
      List<RelationMember<OsmRelationInfo>> relationInfo) {
      super(elem.tags(), name, null, relationInfo, elem.id());
      this.point = point;
      this.line = line;
      this.polygon = polygon;
    }

    @Override
    public Geometry latLonGeometry() throws GeometryException {
      return latLonGeom != null ? latLonGeom : (latLonGeom = GeoUtils.worldToLatLonCoords(worldGeometry()));
    }

    @Override
    public Geometry worldGeometry() throws GeometryException {
      return worldGeom != null ? worldGeom : (worldGeom = computeWorldGeometry());
    }

    protected abstract Geometry computeWorldGeometry() throws GeometryException;

    @Override
    public boolean isPoint() {
      return point;
    }

    @Override
    public boolean canBeLine() {
      return line;
    }

    @Override
    public boolean canBePolygon() {
      return polygon;
    }
  }

  /** A {@link Point} created from an OSM node. */
  private class NodeSourceFeature extends OsmFeature {

    private final long encodedLocation;

    NodeSourceFeature(OsmElement.Node node) {
      super(node, true, false, false, null);
      this.encodedLocation = node.encodedLocation();
    }

    @Override
    protected Geometry computeWorldGeometry() {
      return GeoUtils.point(
        GeoUtils.decodeWorldX(encodedLocation),
        GeoUtils.decodeWorldY(encodedLocation)
      );
    }

    @Override
    public boolean isPoint() {
      return true;
    }

    @Override
    public String toString() {
      return "OsmNode[" + id() + ']';
    }
  }

  /** Returns {@code true} if a way can be interpreted as a line. */
  public static boolean canBeLine(boolean closed, String area, int points) {
    return (!closed || !"yes".equals(area)) && points >= 2;
  }

  /** Returns {@code true} if a way can be interpreted as a polygon. */
  public static boolean canBePolygon(boolean closed, String area, int points) {
    return (closed && !"no".equals(area)) && points >= 4;
  }

  /**
   * A {@link LineString} or {@link Polygon} created from an OSM way.
   * <p>
   * Unclosed rings are always interpreted as linestrings. Closed rings can be interpreted as either a polygon or a
   * linestring unless {@code area=yes} tag prevents them from being a linestring or {@code area=no} tag prevents them
   * from being a polygon.
   */
  private class WaySourceFeature extends OsmFeature {

    private final NodeLocationProvider nodeLocations;
    private final LongArrayList nodeIds;

    public WaySourceFeature(OsmElement.Way way, boolean closed, String area, NodeLocationProvider nodeLocations,
      List<RelationMember<OsmRelationInfo>> relationInfo) {
      super(way, false,
        OsmReader.canBeLine(closed, area, way.nodes().size()),
        OsmReader.canBePolygon(closed, area, way.nodes().size()),
        relationInfo
      );
      this.nodeIds = way.nodes();
      this.nodeLocations = nodeLocations;
    }

    @Override
    protected Geometry computeLine() throws GeometryException {
      try {
        CoordinateSequence coords = nodeLocations.getWayGeometry(nodeIds);
        return GeoUtils.JTS_FACTORY.createLineString(coords);
      } catch (IllegalArgumentException e) {
        throw new GeometryException("osm_invalid_line", "Error building line for way " + id() + ": " + e);
      }
    }

    @Override
    protected Geometry computePolygon() throws GeometryException {
      try {
        CoordinateSequence coords = nodeLocations.getWayGeometry(nodeIds);
        return GeoUtils.JTS_FACTORY.createPolygon(coords);
      } catch (IllegalArgumentException e) {
        throw new GeometryException("osm_invalid_polygon", "Error building polygon for way " + id() + ": " + e);
      }
    }

    @Override
    protected Geometry computeWorldGeometry() throws GeometryException {
      return canBePolygon() ? polygon() : line();
    }

    @Override
    public String toString() {
      return "OsmWay[" + id() + ']';
    }
  }

  /**
   * A {@link MultiPolygon} created from an OSM relation where {@code type=multipolygon}.
   * <p>
   * Delegates complex reconstruction work to {@link OsmMultipolygon}.
   */
  private class MultipolygonSourceFeature extends OsmFeature {

    private final OsmElement.Relation relation;
    private final NodeLocationProvider nodeLocations;

    public MultipolygonSourceFeature(OsmElement.Relation relation, NodeLocationProvider nodeLocations,
      List<RelationMember<OsmRelationInfo>> parentRelations) {
      super(relation, false, false, true, parentRelations);
      this.relation = relation;
      this.nodeLocations = nodeLocations;
    }

    @Override
    protected Geometry computeWorldGeometry() throws GeometryException {
      List<LongArrayList> rings = new ArrayList<>(relation.members().size());
      for (OsmElement.Relation.Member member : relation.members()) {
        String role = member.role();
        LongArrayList poly = multipolygonWayGeometries.get(member.ref());
        if (member.type() == OsmElement.Type.WAY) {
          if (poly != null && !poly.isEmpty()) {
            rings.add(poly);
          } else if (relation.hasTag("type", "multipolygon")) {
            // boundary and land_area relations might not be complete for extracts, but multipolygons should be
            LOGGER.warn(
              "Missing " + role + " OsmWay[" + member.ref() + "] for " + relation.getTag("type") + " " + this);
          }
        }
      }
      return OsmMultipolygon.build(rings, nodeLocations, id());
    }

    @Override
    public String toString() {
      return "OsmRelation[" + id() + ']';
    }
  }

  /**
   * A thin layer on top of {@link LongLongMap} that decodes node locations stored as {@code long} values.
   */
  private class NodeDbLocationProvider implements NodeLocationProvider {

    @Override
    public Coordinate getCoordinate(long id) {
      long encoded = nodeLocationDb.get(id);
      if (encoded == LongLongMap.MISSING_VALUE) {
        throw new IllegalArgumentException("Missing location for node: " + id);
      }
      return new CoordinateXY(GeoUtils.decodeWorldX(encoded), GeoUtils.decodeWorldY(encoded));
    }

    @Override
    public CoordinateSequence getWayGeometry(LongArrayList nodeIds) {
      int num = nodeIds.size();
      CoordinateSequence seq = new PackedCoordinateSequence.Double(nodeIds.size(), 2, 0);

      for (int i = 0; i < num; i++) {
        long encoded = nodeLocationDb.get(nodeIds.get(i));
        if (encoded == LongLongMap.MISSING_VALUE) {
          throw new IllegalArgumentException("Missing location for node: " + nodeIds.get(i));
        }
        seq.setOrdinate(i, 0, GeoUtils.decodeWorldX(encoded));
        seq.setOrdinate(i, 1, GeoUtils.decodeWorldY(encoded));
      }
      return seq;
    }
  }
}