feat(core): add support for GeoJSON representations

search-service/src/main/kotlin/com/egm/stellio/search/web/EntityAccessControlHandler.kt

@@ -75,10 +75,7 @@ class EntityAccessControlHandler(
             mediaType
         )
 
-        val ngsiLdDataRepresentation = parseRepresentations(
-            params.getOrDefault(QUERY_PARAM_OPTIONS, emptyList()),
-            mediaType
-        )
+        val ngsiLdDataRepresentation = parseRepresentations(params, mediaType)
         buildQueryResponse(
             compactedEntities.toFinalRepresentation(ngsiLdDataRepresentation),
             countAndAuthorizedEntities.first,
@@ -126,10 +123,7 @@ class EntityAccessControlHandler(
             mediaType
         )
 
-        val ngsiLdDataRepresentation = parseRepresentations(
-            params.getOrDefault(QUERY_PARAM_OPTIONS, emptyList()),
-            mediaType
-        )
+        val ngsiLdDataRepresentation = parseRepresentations(params, mediaType)
         buildQueryResponse(
             compactedEntities.toFinalRepresentation(ngsiLdDataRepresentation),
             countAndGroupEntities.first,
@@ -178,10 +172,7 @@ class EntityAccessControlHandler(
             mediaType
         )
 
-        val ngsiLdDataRepresentation = parseRepresentations(
-            params.getOrDefault(QUERY_PARAM_OPTIONS, emptyList()),
-            mediaType
-        )
+        val ngsiLdDataRepresentation = parseRepresentations(params, mediaType)
         buildQueryResponse(
             compactedEntities.toFinalRepresentation(ngsiLdDataRepresentation),
             countAndUserEntities.first,

search-service/src/main/kotlin/com/egm/stellio/search/web/EntityHandler.kt

@@ -181,7 +181,7 @@ class EntityHandler(
     /**
      * Implements 6.4.3.2 - Query Entities
      */
-    @GetMapping(produces = [APPLICATION_JSON_VALUE, JSON_LD_CONTENT_TYPE])
+    @GetMapping(produces = [APPLICATION_JSON_VALUE, JSON_LD_CONTENT_TYPE, GEO_JSON_CONTENT_TYPE])
     suspend fun getEntities(
         @RequestHeader httpHeaders: HttpHeaders,
         @RequestParam params: MultiValueMap<String, String>
@@ -208,10 +208,7 @@ class EntityHandler(
             mediaType
         )
 
-        val ngsiLdDataRepresentation = parseRepresentations(
-            params.getOrDefault(QUERY_PARAM_OPTIONS, emptyList()),
-            mediaType
-        )
+        val ngsiLdDataRepresentation = parseRepresentations(params, mediaType)
         buildQueryResponse(
             compactedEntities.toFinalRepresentation(ngsiLdDataRepresentation),
             countAndEntities.second,
@@ -259,10 +256,7 @@ class EntityHandler(
         )
         val compactedEntity = JsonLdUtils.compactEntity(filteredJsonLdEntity, contextLink, mediaType).toMutableMap()
 
-        val ngsiLdDataRepresentation = parseRepresentations(
-            params.getOrDefault(QUERY_PARAM_OPTIONS, emptyList()),
-            mediaType
-        )
+        val ngsiLdDataRepresentation = parseRepresentations(params, mediaType)
         prepareGetSuccessResponse(mediaType, contextLink)
             .body(serializeObject(compactedEntity.toFinalRepresentation(ngsiLdDataRepresentation)))
     }.fold(

search-service/src/main/kotlin/com/egm/stellio/search/web/EntityOperationHandler.kt

@@ -252,7 +252,7 @@ class EntityOperationHandler(
     /**
      * Implements 6.23.3.1 - Query Entities via POST
      */
-    @PostMapping("/query", produces = [MediaType.APPLICATION_JSON_VALUE, JSON_LD_CONTENT_TYPE])
+    @PostMapping("/query", produces = [MediaType.APPLICATION_JSON_VALUE, JSON_LD_CONTENT_TYPE, GEO_JSON_CONTENT_TYPE])
     suspend fun queryEntitiesViaPost(
         @RequestHeader httpHeaders: HttpHeaders,
         @RequestBody requestBody: Mono<String>,
@@ -281,10 +281,7 @@ class EntityOperationHandler(
             mediaType
         )
 
-        val ngsiLdDataRepresentation = parseRepresentations(
-            params.getOrDefault(QUERY_PARAM_OPTIONS, emptyList()),
-            mediaType
-        )
+        val ngsiLdDataRepresentation = parseRepresentations(params, mediaType)
         buildQueryResponse(
             compactedEntities.toFinalRepresentation(ngsiLdDataRepresentation),
             countAndEntities.second,

shared/config/detekt/baseline.xml

@@ -3,9 +3,10 @@
   <ManuallySuppressedIssues></ManuallySuppressedIssues>
   <CurrentIssues>
     <ID>CyclomaticComplexMethod:ExceptionHandler.kt$ExceptionHandler$@ExceptionHandler fun transformErrorResponse(throwable: Throwable): ResponseEntity&lt;ProblemDetail&gt;</ID>
+    <ID>LongMethod:JsonLdEntityTests.kt$JsonLdEntityTests$@Test fun `it should return simplified GeoJSON entities`()</ID>
     <ID>LongMethod:QueryUtils.kt$private fun transformQQueryToSqlJsonPath( mainAttributePath: List&lt;ExpandedTerm&gt;, trailingAttributePath: List&lt;ExpandedTerm&gt;, operator: String, value: String )</ID>
     <ID>LongParameterList:ApiResponses.kt$( body: String, count: Int, resourceUrl: String, paginationQuery: PaginationQuery, requestParams: MultiValueMap&lt;String, String&gt;, mediaType: MediaType, contextLink: String )</ID>
-    <ID>LongParameterList:ApiResponses.kt$( entities: List&lt;CompactedJsonLdEntity&gt;, count: Int, resourceUrl: String, paginationQuery: PaginationQuery, requestParams: MultiValueMap&lt;String, String&gt;, mediaType: MediaType, contextLink: String )</ID>
+    <ID>LongParameterList:ApiResponses.kt$( entities: Any, count: Int, resourceUrl: String, paginationQuery: PaginationQuery, requestParams: MultiValueMap&lt;String, String&gt;, mediaType: MediaType, contextLink: String )</ID>
     <ID>LongParameterList:NgsiLdEntity.kt$NgsiLdEntity$( val id: URI, val types: List&lt;ExpandedTerm&gt;, val scopes: List&lt;String&gt;?, val relationships: List&lt;NgsiLdRelationship&gt;, val properties: List&lt;NgsiLdProperty&gt;, val geoProperties: List&lt;NgsiLdGeoProperty&gt;, val contexts: List&lt;String&gt; )</ID>
     <ID>LongParameterList:NgsiLdEntity.kt$NgsiLdGeoPropertyInstance$( val coordinates: WKTCoordinates, createdAt: ZonedDateTime?, modifiedAt: ZonedDateTime?, observedAt: ZonedDateTime?, datasetId: URI?, properties: List&lt;NgsiLdProperty&gt;, relationships: List&lt;NgsiLdRelationship&gt; )</ID>
     <ID>LongParameterList:NgsiLdEntity.kt$NgsiLdPropertyInstance$( val value: Any, val unitCode: String?, createdAt: ZonedDateTime?, modifiedAt: ZonedDateTime?, observedAt: ZonedDateTime?, datasetId: URI?, properties: List&lt;NgsiLdProperty&gt;, relationships: List&lt;NgsiLdRelationship&gt; )</ID>

shared/src/main/kotlin/com/egm/stellio/shared/model/JsonLdEntity.kt

@@ -5,7 +5,10 @@ import arrow.core.left
 import arrow.core.right
 import com.egm.stellio.shared.util.*
 import com.egm.stellio.shared.util.JsonLdUtils.JSONLD_ID
+import com.egm.stellio.shared.util.JsonLdUtils.JSONLD_ID_TERM
 import com.egm.stellio.shared.util.JsonLdUtils.JSONLD_TYPE
+import com.egm.stellio.shared.util.JsonLdUtils.JSONLD_TYPE_TERM
+import com.egm.stellio.shared.util.JsonLdUtils.JSONLD_VALUE_TERM
 import com.egm.stellio.shared.util.JsonLdUtils.NGSILD_CREATED_AT_PROPERTY
 import com.egm.stellio.shared.util.JsonLdUtils.NGSILD_MODIFIED_AT_PROPERTY
 import com.egm.stellio.shared.util.JsonLdUtils.castAttributeValue
@@ -114,6 +117,21 @@ private fun simplifyValue(value: Map<String, Any>): Any {
     }
 }
 
+fun CompactedJsonLdEntity.toGeoJson(geometryProperty: String): Any {
+    val geometryAttributeContent = this[geometryProperty] as? Map<String, Any>
+    val geometryPropertyValue = geometryAttributeContent?.let {
+        if (it.containsKey(JSONLD_VALUE_TERM)) it[JSONLD_VALUE_TERM]
+        else it
+    }
+
+    return mapOf(
+        JSONLD_ID_TERM to this[JSONLD_ID_TERM]!!,
+        JSONLD_TYPE_TERM to FEATURE_TYPE,
+        GEOMETRY_PROPERTY_TERM to geometryPropertyValue,
+        PROPERTIES_PROPERTY_TERM to this.filter { it.key != JSONLD_ID_TERM }
+    )
+}
+
 fun CompactedJsonLdEntity.withoutSysAttrs(): Map<String, Any> =
     this.filter {
         !JsonLdUtils.NGSILD_SYSATTRS_TERMS.contains(it.key)
@@ -133,18 +151,30 @@ fun CompactedJsonLdEntity.withoutSysAttrs(): Map<String, Any> =
 
 fun CompactedJsonLdEntity.toFinalRepresentation(
     ngsiLdDataRepresentation: NgsiLdDataRepresentation
-): CompactedJsonLdEntity =
+): Any =
     this.let {
         if (!ngsiLdDataRepresentation.includeSysAttrs) it.withoutSysAttrs()
         else it
     }.let {
         if (ngsiLdDataRepresentation.attributeRepresentation == AttributeRepresentation.SIMPLIFIED) it.toKeyValues()
         else it
+    }.let {
+        if (ngsiLdDataRepresentation.entityRepresentation == EntityRepresentation.GEO_JSON)
+            // geometryProperty is not null when GeoJSON representation is asked (defaults to location)
+            it.toGeoJson(ngsiLdDataRepresentation.geometryProperty!!)
+        else it
     }
 
 fun List<CompactedJsonLdEntity>.toFinalRepresentation(
     ngsiLdDataRepresentation: NgsiLdDataRepresentation
-): List<CompactedJsonLdEntity> =
+): Any =
     this.map {
         it.toFinalRepresentation(ngsiLdDataRepresentation)
+    }.let {
+        if (ngsiLdDataRepresentation.entityRepresentation == EntityRepresentation.GEO_JSON) {
+            mapOf(
+                JSONLD_TYPE_TERM to FEATURE_COLLECTION_TYPE,
+                FEATURES_PROPERTY_TERM to it
+            )
+        } else it
     }

shared/src/main/kotlin/com/egm/stellio/shared/model/NgsiLdDataRepresentation.kt

@@ -10,7 +10,10 @@ import org.springframework.http.MediaType
 data class NgsiLdDataRepresentation(
     val entityRepresentation: EntityRepresentation,
     val attributeRepresentation: AttributeRepresentation,
-    val includeSysAttrs: Boolean
+    val includeSysAttrs: Boolean,
+    // In the case of GeoJSON Entity representation,
+    // this parameter indicates which GeoProperty to use for the toplevel geometry field
+    val geometryProperty: String? = null
 )
 
 enum class AttributeRepresentation {

shared/src/main/kotlin/com/egm/stellio/shared/util/ApiResponses.kt

@@ -98,7 +98,7 @@ fun missingPathErrorResponse(errorMessage: String): ResponseEntity<*> {
 }
 
 fun buildQueryResponse(
-    entities: List<CompactedJsonLdEntity>,
+    entities: Any,
     count: Int,
     resourceUrl: String,
     paginationQuery: PaginationQuery,

shared/src/main/kotlin/com/egm/stellio/shared/util/ApiUtils.kt

@@ -8,6 +8,7 @@ import arrow.core.right
 import arrow.fx.coroutines.parMap
 import com.egm.stellio.shared.model.*
 import com.egm.stellio.shared.util.JsonLdUtils.JSONLD_CONTEXT
+import com.egm.stellio.shared.util.JsonLdUtils.NGSILD_LOCATION_TERM
 import com.egm.stellio.shared.util.JsonLdUtils.extractContextFromInput
 import com.egm.stellio.shared.util.JsonUtils.deserializeAsMap
 import kotlinx.coroutines.reactive.awaitFirst
@@ -34,6 +35,7 @@ const val QUERY_PARAM_ID_PATTERN: String = "idPattern"
 const val QUERY_PARAM_ATTRS: String = "attrs"
 const val QUERY_PARAM_Q: String = "q"
 const val QUERY_PARAM_SCOPEQ: String = "scopeQ"
+const val QUERY_PARAM_GEOMETRY_PROPERTY: String = "geometryProperty"
 const val QUERY_PARAM_OPTIONS: String = "options"
 const val QUERY_PARAM_OPTIONS_SYSATTRS_VALUE: String = "sysAttrs"
 const val QUERY_PARAM_OPTIONS_KEYVALUES_VALUE: String = "keyValues"
@@ -171,17 +173,24 @@ fun parseAndExpandRequestParameter(requestParam: String?, contextLink: String):
         }.toSet()
 
 fun parseRepresentations(
-    optionsParam: List<String>,
+    requestParams: MultiValueMap<String, String>,
     acceptMediaType: MediaType
 ): NgsiLdDataRepresentation {
+    val optionsParam = requestParams.getOrDefault(QUERY_PARAM_OPTIONS, emptyList())
     val includeSysAttrs = optionsParam.contains(QUERY_PARAM_OPTIONS_SYSATTRS_VALUE)
     val attributeRepresentation = optionsParam.contains(QUERY_PARAM_OPTIONS_KEYVALUES_VALUE)
         .let { if (it) AttributeRepresentation.SIMPLIFIED else AttributeRepresentation.NORMALIZED }
+    val entityRepresentation = EntityRepresentation.forMediaType(acceptMediaType)
+    val geometryProperty =
+        if (entityRepresentation == EntityRepresentation.GEO_JSON)
+            requestParams.getFirst(QUERY_PARAM_GEOMETRY_PROPERTY) ?: NGSILD_LOCATION_TERM
+        else null
 
     return NgsiLdDataRepresentation(
-        EntityRepresentation.forMediaType(acceptMediaType),
+        entityRepresentation,
         attributeRepresentation,
-        includeSysAttrs
+        includeSysAttrs,
+        geometryProperty
     )
 }
 
@@ -233,7 +242,7 @@ fun List<MediaType>.getApplicable(): Either<APIException, MediaType> {
     return if (mediaType.includes(MediaType.APPLICATION_JSON))
         MediaType.APPLICATION_JSON.right()
     else
-        JSON_LD_MEDIA_TYPE.right()
+        mediaType.right()
 }
 
 fun String.parseTimeParameter(errorMsg: String): Either<String, ZonedDateTime> =

shared/src/main/kotlin/com/egm/stellio/shared/util/GeoUtils.kt

@@ -14,6 +14,12 @@ import org.locationtech.jts.io.WKTWriter
 import org.locationtech.jts.io.geojson.GeoJsonReader
 import org.locationtech.jts.io.geojson.GeoJsonWriter
 
+const val FEATURE_TYPE = "Feature"
+const val FEATURE_COLLECTION_TYPE = "FeatureCollection"
+const val GEOMETRY_PROPERTY_TERM = "geometry"
+const val PROPERTIES_PROPERTY_TERM = "properties"
+const val FEATURES_PROPERTY_TERM = "features"
+
 fun geoJsonToWkt(geometryType: GeoQuery.GeometryType, coordinates: String): Either<APIException, WKTCoordinates> =
     geoJsonToWkt(
         """