Add entity type facet to search response

modules/search-api/src/main/scala/io/renku/search/api/SearchApiImpl.scala

@@ -25,9 +25,12 @@ import io.renku.search.api.data.*
 import io.renku.search.model.users
 import io.renku.search.solr.client.SearchSolrClient
 import io.renku.search.solr.documents.Entity as SolrEntity
+import io.renku.search.solr.schema.EntityDocumentSchema.Fields
 import io.renku.solr.client.QueryResponse
 import org.http4s.dsl.Http4sDsl
 import scribe.Scribe
+import io.renku.search.model.EntityType
+import io.renku.solr.client.facet.FacetResponse
 
 private class SearchApiImpl[F[_]: Async](solrClient: SearchSolrClient[F])
     extends Http4sDsl[F]
@@ -58,9 +61,19 @@ private class SearchApiImpl[F[_]: Async](solrClient: SearchSolrClient[F])
   ): SearchResult =
     val hasMore = solrResult.responseBody.docs.size > currentPage.limit
     val pageInfo = PageWithTotals(currentPage, solrResult.responseBody.numFound, hasMore)
+    val facets = solrResult.facetResponse
+      .flatMap(_.buckets.get(Fields.entityType))
+      .map { counts =>
+        val all =
+          counts.buckets.flatMap { case FacetResponse.Bucket(key, count) =>
+            EntityType.fromString(key).toOption.map(et => et -> count)
+          }.toMap
+        FacetData(all)
+      }
+      .getOrElse(FacetData.empty)
     val items = solrResult.responseBody.docs.map(toApiEntity)
-    if (hasMore) SearchResult(items.init, pageInfo)
-    else SearchResult(items, pageInfo)
+    if (hasMore) SearchResult(items.init, facets, pageInfo)
+    else SearchResult(items, facets, pageInfo)
 
   private lazy val toApiEntity: SolrEntity => SearchEntity =
     given Transformer[users.Id, UserId] = (id: users.Id) => UserId(id)

modules/search-api/src/main/scala/io/renku/search/api/data/FacetData.scala

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2024 Swiss Data Science Center (SDSC)
+ * A partnership between École Polytechnique Fédérale de Lausanne (EPFL) and
+ * Eidgenössische Technische Hochschule Zürich (ETHZ).
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.renku.search.api.data
+
+import io.renku.search.model.EntityType
+import io.bullet.borer.Decoder
+import io.bullet.borer.derivation.MapBasedCodecs
+import sttp.tapir.Schema
+import io.bullet.borer.Encoder
+import io.renku.search.api.tapir.SchemaSyntax.*
+
+final case class FacetData(
+    entityType: Map[EntityType, Int]
+)
+
+object FacetData:
+  val empty: FacetData = FacetData(Map.empty)
+
+  given Decoder[FacetData] = MapBasedCodecs.deriveDecoder
+  given Encoder[FacetData] = MapBasedCodecs.deriveEncoder
+  given Schema[FacetData] = {
+    given Schema[Map[EntityType, Int]] = Schema.schemaForMap(_.name)
+    Schema
+      .derived[FacetData]
+      .jsonExample(
+        FacetData(
+          Map(
+            EntityType.Project -> 15,
+            EntityType.User -> 3
+          )
+        )
+      )
+  }

modules/search-api/src/main/scala/io/renku/search/api/data/SearchResult.scala

@@ -25,6 +25,7 @@ import sttp.tapir.Schema
 
 final case class SearchResult(
     items: Seq[SearchEntity],
+    facets: FacetData,
     pagingInfo: PageWithTotals
 )
 

modules/search-api/src/main/scala/io/renku/search/api/tapir/SchemaSyntax.scala

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2024 Swiss Data Science Center (SDSC)
+ * A partnership between École Polytechnique Fédérale de Lausanne (EPFL) and
+ * Eidgenössische Technische Hochschule Zürich (ETHZ).
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.renku.search.api.tapir
+
+import io.bullet.borer.Encoder
+import io.bullet.borer.Json
+import sttp.tapir.Schema
+
+trait SchemaSyntax:
+
+  extension [T](self: Schema[T])
+    def jsonExample(value: T)(using Encoder[T]): Schema[T] =
+      self.encodedExample(Json.encode(value).toUtf8String)
+
+object SchemaSyntax extends SchemaSyntax

modules/search-api/src/main/scala/io/renku/search/api/tapir/TapirCodecs.scala

@@ -21,10 +21,18 @@ package io.renku.search.api.tapir
 import sttp.tapir.*
 import io.renku.search.api.data.*
 import io.renku.search.query.Query
+import io.renku.search.model.EntityType
 
 trait TapirCodecs:
   given Codec[String, Query, CodecFormat.TextPlain] =
     Codec.string.mapEither(Query.parse(_))(_.render)
 
   given Schema[Query] = Schema.anyObject[Query]
   given Schema[QueryInput] = Schema.derived
+
+  given Codec[String, EntityType, CodecFormat.TextPlain] =
+    Codec.string.mapEither(EntityType.fromString(_))(_.name)
+
+  given Schema[EntityType] = Schema.derivedEnumeration.defaultStringBased
+
+object TapirCodecs extends TapirCodecs

modules/search-solr-client/src/main/scala/io/renku/search/solr/client/SearchSolrClientImpl.scala

@@ -26,13 +26,20 @@ import io.renku.search.solr.documents.Entity
 import io.renku.search.solr.query.LuceneQueryInterpreter
 import io.renku.solr.client.{QueryData, QueryResponse, QueryString, SolrClient}
 import io.renku.solr.client.schema.FieldName
+import io.renku.solr.client.facet.{Facet, Facets}
+import io.renku.search.solr.schema.EntityDocumentSchema
 
 private class SearchSolrClientImpl[F[_]: Async](solrClient: SolrClient[F])
     extends SearchSolrClient[F]:
 
   private[this] val logger = scribe.cats.effect[F]
   private[this] val interpreter = LuceneQueryInterpreter.forSync[F]
 
+  private val typeTerms = Facet.Terms(
+    EntityDocumentSchema.Fields.entityType,
+    EntityDocumentSchema.Fields.entityType
+  )
+
   override def insert[D: Encoder](documents: Seq[D]): F[Unit] =
     solrClient.insert(documents).void
 
@@ -48,6 +55,7 @@ private class SearchSolrClientImpl[F[_]: Async](solrClient: SolrClient[F])
         .query[Entity](
           QueryData(QueryString(solrQuery.query.value, limit, offset))
             .withSort(solrQuery.sort)
+            .withFacet(Facets(typeTerms))
             .withFields(FieldName.all, FieldName.score)
         )
     } yield res

nix/openapi-doc.nix

@@ -20,7 +20,7 @@
         <script>
          window.onload = () => {
              window.ui = SwaggerUIBundle({
-                 url: 'http://localhost:8080/apiv2/search/spec.json',
+                 url: 'http://localhost:8080/search/spec.json',
                  dom_id: '#swagger-ui',
                  presets: [
                      SwaggerUIBundle.presets.apis,