[GEOS-8611] Allow DescribeDomain to return a selection of dimensions (#…

…2779)

[GEOS-8611] Allow DescribeDomain to return a selection of dimensions

doc/en/user/source/community/wmts-multidimensional/index.rst

@@ -154,14 +154,17 @@ This operation is useful to understand which domains are available in our layer
    * - TileMatrixSet
      - Yes
      - Tile matrix set identifier
-   * - BBOX=minx,miny,maxx,maxy
+   * - bbox=minx,miny,maxx,maxy
      - No
      - Bounding box corners (lower left, upper right) in CRS units
    * - DimensionIdentifier
      - No
      - At most one per dimension, a range described as min/max, restricting the domain of this dimension
+   * - Domains
+     - No
+     - A comma separated list of domain names to be returned, in case only a subset is required. The space domain is identified by "bbox".
 
-The ``BBOX`` parameter allows the client to restrict the ``DescribeDomains`` operation to a certain spatial area, by default the layer extent will be used.
+The ``bbox`` parameter allows the client to restrict the ``DescribeDomains`` operation to a certain spatial area, by default the layer extent will be used.
 
 The ``DimensionIdentifier`` parameter can be used to restrict the domain values of a certain dimension, this is useful to answer questions like which elevations values are available in a specific day.
 
@@ -233,6 +236,23 @@ the result will be similar to this:
 
 So for time 2016-02-23T03:00:00.000Z there is only values measured at 200.0 meters.
 
+In case only the space domain is of interest, the following request will do:
+
+.. code-block:: guess
+
+  http://localhost:8080/geoserver/gwc/service/wmts?REQUEST=DescribeDomains&Version=1.0.0&Layer=some_layer&TileMatrixSet=EPSG:4326&elevation=0/500&time=2016-02-23T03:00:00.000Z&domains=bbox
+
+and the result will be similar to this:
+
+.. code-block:: xml
+
+  <Domains xmlns="http://demo.geo-solutions.it/share/wmts-multidim/wmts_multi_dimensional.xsd" xmlns:ows="http://www.opengis.net/ows/1.1">
+    <SpaceDomain>
+      <BoundingBox CRS="EPSG:4326" 
+       maxx="179.875" maxy="89.9375" minx="-180.125" miny="-90.125"/>
+    </SpaceDomain>
+  </Domains>
+
 GetHistogram
 ^^^^^^^^^^^^
 

src/community/wmts-multi-dimensional/src/main/java/org/geoserver/gwc/wmts/DescribeDomainsTransformer.java

@@ -54,13 +54,13 @@ public void encode(Object object) throws IllegalArgumentException {
             });
             start("Domains", nameSpaces);
             Map<String, Tuple<Integer, List<String>>> domainsValues = new HashMap<>();
-            ReferencedEnvelope referencedEnvelope = new ReferencedEnvelope();
             domains.getDimensions().forEach(dimension -> {
-                Tuple<ReferencedEnvelope, Tuple<Integer, List<String>>> dimensionValues = dimension.getDomainValuesAsStrings(domains.getFilter());
-                referencedEnvelope.expandToInclude(dimensionValues.first);
-                domainsValues.put(dimension.getDimensionName(), dimensionValues.second);
+                Tuple<Integer, List<String>> dimensionValues = dimension.getDomainValuesAsStrings(domains.getFilter());
+                domainsValues.put(dimension.getDimensionName(), dimensionValues);
             });
-            handleBoundingBox(referencedEnvelope);
+            if (domains.getSpatialDomain() != null && !domains.getSpatialDomain().isEmpty()) {
+                handleBoundingBox(domains.getSpatialDomain());
+            }
             domainsValues.entrySet().forEach(dimensionValues -> handleDimension(dimensionValues.getKey(), dimensionValues.getValue()));
             end("Domains");
         }

src/community/wmts-multi-dimensional/src/main/java/org/geoserver/gwc/wmts/Domains.java

@@ -27,7 +27,7 @@
 public class Domains {
 
     private final List<Dimension> dimensions;
-    private final ReferencedEnvelope boundingBox;
+    private final ReferencedEnvelope spatialDomain;
     private final Filter filter;
 
     private final LayerInfo layerInfo;
@@ -38,16 +38,16 @@ public class Domains {
     public Domains(List<Dimension> dimensions, LayerInfo layerInfo, ReferencedEnvelope boundingBox, Filter filter) {
         this.dimensions = dimensions;
         this.layerInfo = layerInfo;
-        this.boundingBox = boundingBox;
+        this.spatialDomain = boundingBox;
         this.filter = filter;
     }
 
     public List<Dimension> getDimensions() {
         return dimensions;
     }
 
-    ReferencedEnvelope getBoundingBox() {
-        return boundingBox;
+    ReferencedEnvelope getSpatialDomain() {
+        return spatialDomain;
     }
 
     public Filter getFilter() {

src/community/wmts-multi-dimensional/src/main/java/org/geoserver/gwc/wmts/MultiDimensionalExtension.java

@@ -5,8 +5,12 @@
 package org.geoserver.gwc.wmts;
 
 import org.geoserver.catalog.Catalog;
+import org.geoserver.catalog.CoverageInfo;
+import org.geoserver.catalog.DimensionInfo;
+import org.geoserver.catalog.FeatureTypeInfo;
 import org.geoserver.catalog.LayerInfo;
 import org.geoserver.catalog.PublishedInfo;
+import org.geoserver.catalog.ResourceInfo;
 import org.geoserver.catalog.WorkspaceInfo;
 import org.geoserver.gwc.layer.CatalogConfiguration;
 import org.geoserver.gwc.layer.GeoServerTileLayer;
@@ -17,16 +21,16 @@
 import org.geoserver.ows.util.KvpUtils;
 import org.geoserver.platform.ServiceException;
 import org.geoserver.wms.WMS;
+import org.geoserver.wms.dimension.DimensionFilterBuilder;
 import org.geotools.factory.CommonFactoryFinder;
 import org.geotools.filter.visitor.SimplifyingFilterVisitor;
 import org.geotools.geometry.jts.ReferencedEnvelope;
+import org.geotools.gml2.bindings.GML2EncodingUtils;
 import org.geotools.referencing.CRS;
-import org.geotools.resources.CRSUtilities;
 import org.geotools.util.logging.Logging;
 import org.geowebcache.GeoWebCacheException;
 import org.geowebcache.conveyor.Conveyor;
 import org.geowebcache.grid.GridSubset;
-import org.geowebcache.grid.SRS;
 import org.geowebcache.io.XMLBuilder;
 import org.geowebcache.layer.TileLayer;
 import org.geowebcache.layer.TileLayerDispatcher;
@@ -35,12 +39,18 @@
 import org.geowebcache.storage.StorageBroker;
 import org.opengis.filter.Filter;
 import org.opengis.filter.FilterFactory;
+import org.opengis.referencing.crs.CoordinateReferenceSystem;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -51,6 +61,8 @@
 public final class MultiDimensionalExtension extends WMTSExtensionImpl {
 
     private final static Logger LOGGER = Logging.getLogger(MultiDimensionalExtension.class);
+    public static final String SPACE_DIMENSION = "bbox";
+    public static final Set<String> ALL_DOMAINS = Collections.emptySet();
 
     private final FilterFactory filterFactory = CommonFactoryFinder.getFilterFactory();
 
@@ -101,26 +113,23 @@ public boolean handleRequest(Conveyor candidateConveyor) throws OWSException {
                     executeDescribeDomainsOperation(conveyor);
                 } catch (Exception exception) {
                     LOGGER.log(Level.SEVERE, "Error executing describe domains operation.", exception);
-                    throw new OWSException(500, "NoApplicableCode", "",
-                            "Error executing describe domains operation:" + exception.getMessage());
+                    return rethrowException(exception, "Error executing describe domains operation:");
                 }
                 break;
             case GET_HISTOGRAM:
                 try {
                     executeGetHistogramOperation(conveyor);
                 } catch (Exception exception) {
                     LOGGER.log(Level.SEVERE, "Error executing get histogram operation.", exception);
-                    throw new OWSException(500, "NoApplicableCode", "",
-                            "Error executing get histogram operation:" + exception.getMessage());
+                    rethrowException(exception, "Error executing get histogram operation:");
                 }
                 break;
             case GET_FEATURE:
                 try {
                     executeGetFeatureOperation(conveyor);
                 } catch (Exception exception) {
                     LOGGER.log(Level.SEVERE, "Error executing get feature operation.", exception);
-                    throw new OWSException(500, "NoApplicableCode", "",
-                            "Error executing get feature operation:" + exception.getMessage());
+                    rethrowException(exception, "Error executing get feature operation:");
                 }
                 break;
             default:
@@ -129,24 +138,37 @@ public boolean handleRequest(Conveyor candidateConveyor) throws OWSException {
         return true;
     }
 
+    public boolean rethrowException(Exception exception, String s) throws OWSException {
+        if (exception instanceof OWSException) {
+            throw (OWSException) exception;
+        }
+        throw new OWSException(500, "NoApplicableCode", "", s + exception.getMessage());
+    }
+
     @Override
     public void encodeLayer(XMLBuilder xmlBuilder, TileLayer tileLayer) throws IOException {
         LayerInfo layerInfo = getLayerInfo(tileLayer, tileLayer.getName());
         if (layerInfo == null) {
             // dimension are not supported for this layer (maybe is a layer group)
             return;
         }
-        List<Dimension> dimensions = DimensionsUtils.extractDimensions(wms, layerInfo);
-        encodeLayerDimensions(xmlBuilder, dimensions);
+        try {
+            List<Dimension> dimensions = DimensionsUtils.extractDimensions(wms, layerInfo, ALL_DOMAINS);
+            encodeLayerDimensions(xmlBuilder, dimensions);
+        } catch (OWSException e) {
+            // should not happen
+            throw new RuntimeException(e);
+        }
     }
 
     private Domains getDomains(SimpleConveyor conveyor) throws Exception {
         // getting and parsing the mandatory parameters
         String layerName = (String) conveyor.getParameter("layer", true);
         TileLayer tileLayer = tileLayerDispatcher.getTileLayer(layerName);
         LayerInfo layerInfo = getLayerInfo(tileLayer, layerName);
+        Set<String> requestedDomains = getRequestedDomains(conveyor.getParameter("domains", false));
         // getting this layer dimensions along with its values
-        List<Dimension> dimensions = DimensionsUtils.extractDimensions(wms, layerInfo);
+        List<Dimension> dimensions = DimensionsUtils.extractDimensions(wms, layerInfo, requestedDomains);
         // let's see if we have a spatial limitation
         ReferencedEnvelope boundingBox = (ReferencedEnvelope) conveyor.getParameter("bbox", false);
         // if we have a bounding box we need to set the crs based on the tile matrix set
@@ -162,15 +184,42 @@ private Domains getDomains(SimpleConveyor conveyor) throws Exception {
             boundingBox = new ReferencedEnvelope(boundingBox, CRS.decode(gridSubset.getSRS().toString()));
         }
         // add any domain provided restriction and set the bounding box
-        Filter filter = Filter.INCLUDE;
+        ResourceInfo resource = layerInfo.getResource();
+        Filter filter = DimensionsUtils.getBoundingBoxFilter(resource, boundingBox, filterFactory);
         for (Dimension dimension : dimensions) {
             Object restriction = conveyor.getParameter(dimension.getDimensionName(), false);
-            dimension.setBoundingBox(boundingBox);
-            dimension.addDomainRestriction(restriction);
-            filter = filterFactory.and(filter, dimension.getFilter());
+            if (restriction != null) {
+                Tuple<String, String> attributes = DimensionsUtils.getAttributes(resource, dimension);
+                filter = appendDomainRestrictionsFilter(filter, attributes.first, attributes.second, restriction);
+            }
         }
+        // compute the bounding box
+        ReferencedEnvelope spatialDomain = null;
+        if (requestedDomains == ALL_DOMAINS || requestedDomains.contains(SPACE_DIMENSION)) {
+            spatialDomain = DimensionsUtils.getBounds(resource, filter);  
+        } 
         // encode the domains
-        return new Domains(dimensions, layerInfo, boundingBox, SimplifyingFilterVisitor.simplify(filter));
+        return new Domains(dimensions, layerInfo, spatialDomain, SimplifyingFilterVisitor.simplify(filter));
+    }
+
+    /**
+     * Helper method that will build a dimension domain values filter based on this dimension start and end
+     * attributes. The created filter will be merged with the provided filter.
+     */
+    protected Filter appendDomainRestrictionsFilter(Filter filter, String startAttribute, String endAttribute, Object domainRestrictions) {
+        DimensionFilterBuilder dimensionFilterBuilder = new DimensionFilterBuilder(filterFactory);
+        List<Object> restrictionList = domainRestrictions instanceof Collection ? new ArrayList<>((Collection) domainRestrictions) : Arrays.asList(domainRestrictions);
+        dimensionFilterBuilder.appendFilters(startAttribute, endAttribute, restrictionList);
+        return filterFactory.and(filter, dimensionFilterBuilder.getFilter());
+    }
+
+    private Set<String> getRequestedDomains(Object domains) {
+        if (domains == null) {
+            return ALL_DOMAINS;
+        }
+
+        String[] domainNames = domains.toString().trim().split("\\s*,\\s*");
+        return new LinkedHashSet<>(Arrays.asList(domainNames));
     }
 
     private void executeDescribeDomainsOperation(SimpleConveyor conveyor) throws Exception {
@@ -242,7 +291,7 @@ private void encodeLayerDimension(XMLBuilder xml, Dimension dimension) throws IO
         xml.simpleElement("ows:Identifier", dimension.getDimensionName(), true);
         // default value is mandatory
         xml.simpleElement("Default", dimension.getDefaultValueAsString(), true);
-        for (String value : dimension.getDomainValuesAsStrings(Filter.INCLUDE).second.second) {
+        for (String value : dimension.getDomainValuesAsStrings(Filter.INCLUDE).second) {
             xml.simpleElement("Value", value, true);
         }
         xml.endElement("Dimension");