Added support for transformation of explore request (#224)

* Added support for transformation of explore request

* Update hypertrace-graphql-explorer-schema/src/main/java/org/hypertrace/graphql/explorer/request/DefaultExploreRequestBuilder.java

Co-authored-by: Aaron Steinfeld <[email protected]>

---------

Co-authored-by: Aaron Steinfeld <[email protected]>

Author: avinashkolluru

hypertrace-graphql-explorer-schema/src/main/java/org/hypertrace/graphql/explorer/request/DefaultExploreRequestBuilder.java

@@ -6,6 +6,7 @@
 import graphql.schema.DataFetchingFieldSelectionSet;
 import io.reactivex.rxjava3.core.Observable;
 import io.reactivex.rxjava3.core.Single;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -190,6 +191,46 @@ public Single<ExploreRequest> build(
                 groupBy.map(GroupByArgument::groupLimit)));
   }
 
+  @Override
+  public Single<ExploreRequest> rebuildWithAdditionalFilters(
+      ExploreRequest originalRequest, List<FilterArgument> additionalFilterArguments) {
+    return this.mergeFilterLists(
+            originalRequest.context(),
+            originalRequest.scope(),
+            originalRequest.filterArguments(),
+            additionalFilterArguments)
+        .map(
+            newFilterArguments ->
+                new DefaultExploreRequest(
+                    originalRequest.context(),
+                    originalRequest.scope(),
+                    originalRequest.timeRange(),
+                    originalRequest.limit(),
+                    originalRequest.offset(),
+                    originalRequest.attributeRequests(),
+                    originalRequest.aggregationRequests(),
+                    originalRequest.orderArguments(),
+                    newFilterArguments,
+                    originalRequest.groupByAttributeRequests(),
+                    originalRequest.timeInterval(),
+                    originalRequest.entityContextOptions(),
+                    originalRequest.includeRest(),
+                    originalRequest.spaceId(),
+                    originalRequest.groupLimit()));
+  }
+
+  private Single<List<AttributeAssociation<FilterArgument>>> mergeFilterLists(
+      GraphQlRequestContext requestContext,
+      String scope,
+      Collection<AttributeAssociation<FilterArgument>> original,
+      Collection<FilterArgument> additional) {
+    return this.filterRequestBuilder
+        .build(requestContext, scope, additional)
+        .flattenAsObservable(list -> list)
+        .concatWith(Observable.fromIterable(original))
+        .toList();
+  }
+
   private Single<Set<AttributeRequest>> buildGroupByAttributes(
       GraphQlRequestContext context,
       String explorerScope,

hypertrace-graphql-explorer-schema/src/main/java/org/hypertrace/graphql/explorer/request/ExploreRequestBuilder.java

@@ -36,4 +36,7 @@ Single<ExploreRequest> build(
       Optional<EntityContextOptions> entityContextOptions,
       Single<Set<AttributeRequest>> attributeSelections,
       Single<Set<MetricAggregationRequest>> aggregationSelections);
+
+  Single<ExploreRequest> rebuildWithAdditionalFilters(
+      ExploreRequest originalRequest, List<FilterArgument> filterArguments);
 }