Allow sorting in [rev]include results. (google#2200)

* Allow sorting in [rev]include results

* Review comment changes

* Fixed failing tests

* Lint fails build because of the use of restricted api  from  package. So, supressing it as couldn't find a workaround for the api

* Spotless

* Updated failing test

* Review comments: Fixed tests

* Review comments: Refactored db code to separate out search functions for forward and rev include

* Lint fails build because of the use of restricted api UUIDUtil.convertUUIDToByte from androidx.room package. So, supressing it as couldn't find a workaround for the api

* Review Comments: Unified the usage of getSortOrder

* Review comments: Updated kdoc

engine/src/main/java/com/google/android/fhir/FhirEngine.kt

@@ -153,42 +153,4 @@ data class SearchResult<R : Resource>(
   val included: Map<SearchParamName, List<Resource>>?,
   /** Matching referenced resources as per the [Search.revInclude] criteria in the query. */
   val revIncluded: Map<Pair<ResourceType, SearchParamName>, List<Resource>>?,
-) {
-  override fun equals(other: Any?) =
-    other is SearchResult<*> &&
-      equalsShallow(resource, other.resource) &&
-      equalsShallow(included, other.included) &&
-      equalsShallow(revIncluded, other.revIncluded)
-
-  private fun equalsShallow(first: Resource, second: Resource) =
-    first.resourceType == second.resourceType && first.logicalId == second.logicalId
-
-  private fun equalsShallow(first: List<Resource>, second: List<Resource>) =
-    first.size == second.size &&
-      first.asSequence().zip(second.asSequence()).all { (x, y) -> equalsShallow(x, y) }
-
-  private fun equalsShallow(
-    first: Map<SearchParamName, List<Resource>>?,
-    second: Map<SearchParamName, List<Resource>>?,
-  ) =
-    if (first != null && second != null && first.size == second.size) {
-      first.entries.asSequence().zip(second.entries.asSequence()).all { (x, y) ->
-        x.key == y.key && equalsShallow(x.value, y.value)
-      }
-    } else {
-      first?.size == second?.size
-    }
-
-  @JvmName("equalsShallowRevInclude")
-  private fun equalsShallow(
-    first: Map<Pair<ResourceType, SearchParamName>, List<Resource>>?,
-    second: Map<Pair<ResourceType, SearchParamName>, List<Resource>>?,
-  ) =
-    if (first != null && second != null && first.size == second.size) {
-      first.entries.asSequence().zip(second.entries.asSequence()).all { (x, y) ->
-        x.key == y.key && equalsShallow(x.value, y.value)
-      }
-    } else {
-      first?.size == second?.size
-    }
-}
+)

engine/src/main/java/com/google/android/fhir/db/Database.kt

@@ -18,7 +18,8 @@ package com.google.android.fhir.db
 
 import com.google.android.fhir.LocalChange
 import com.google.android.fhir.LocalChangeToken
-import com.google.android.fhir.db.impl.dao.IndexedIdAndResource
+import com.google.android.fhir.db.impl.dao.ForwardIncludeSearchResult
+import com.google.android.fhir.db.impl.dao.ReverseIncludeSearchResult
 import com.google.android.fhir.db.impl.entities.LocalChangeEntity
 import com.google.android.fhir.db.impl.entities.ResourceEntity
 import com.google.android.fhir.search.SearchQuery
@@ -94,9 +95,11 @@ internal interface Database {
    */
   suspend fun delete(type: ResourceType, id: String)
 
-  suspend fun <R : Resource> search(query: SearchQuery): List<R>
+  suspend fun <R : Resource> search(query: SearchQuery): List<ResourceWithUUID<R>>
 
-  suspend fun searchReferencedResources(query: SearchQuery): List<IndexedIdAndResource>
+  suspend fun searchForwardReferencedResources(query: SearchQuery): List<ForwardIncludeSearchResult>
+
+  suspend fun searchReverseReferencedResources(query: SearchQuery): List<ReverseIncludeSearchResult>
 
   suspend fun count(query: SearchQuery): Long
 
@@ -183,3 +186,8 @@ internal interface Database {
    */
   suspend fun purge(type: ResourceType, id: String, forcePurge: Boolean = false)
 }
+
+data class ResourceWithUUID<R>(
+  val uuid: UUID,
+  val resource: R,
+)

engine/src/main/java/com/google/android/fhir/db/impl/DatabaseImpl.kt

@@ -27,8 +27,10 @@ import com.google.android.fhir.DatabaseErrorStrategy
 import com.google.android.fhir.LocalChange
 import com.google.android.fhir.LocalChangeToken
 import com.google.android.fhir.db.ResourceNotFoundException
+import com.google.android.fhir.db.ResourceWithUUID
 import com.google.android.fhir.db.impl.DatabaseImpl.Companion.UNENCRYPTED_DATABASE_NAME
-import com.google.android.fhir.db.impl.dao.IndexedIdAndResource
+import com.google.android.fhir.db.impl.dao.ForwardIncludeSearchResult
+import com.google.android.fhir.db.impl.dao.ReverseIncludeSearchResult
 import com.google.android.fhir.db.impl.entities.ResourceEntity
 import com.google.android.fhir.index.ResourceIndexer
 import com.google.android.fhir.logicalId
@@ -199,23 +201,43 @@ internal class DatabaseImpl(
     }
   }
 
-  override suspend fun <R : Resource> search(query: SearchQuery): List<R> {
+  override suspend fun <R : Resource> search(
+    query: SearchQuery,
+  ): List<ResourceWithUUID<R>> {
     return db.withTransaction {
       resourceDao
         .getResources(SimpleSQLiteQuery(query.query, query.args.toTypedArray()))
-        .map { iParser.parseResource(it) as R }
-        .distinctBy { it.id }
+        .map { ResourceWithUUID(it.uuid, iParser.parseResource(it.serializedResource) as R) }
+        .distinctBy { it.uuid }
     }
   }
 
-  override suspend fun searchReferencedResources(query: SearchQuery): List<IndexedIdAndResource> {
+  override suspend fun searchForwardReferencedResources(
+    query: SearchQuery,
+  ): List<ForwardIncludeSearchResult> {
     return db.withTransaction {
       resourceDao
-        .getReferencedResources(SimpleSQLiteQuery(query.query, query.args.toTypedArray()))
+        .getForwardReferencedResources(SimpleSQLiteQuery(query.query, query.args.toTypedArray()))
         .map {
-          IndexedIdAndResource(
+          ForwardIncludeSearchResult(
             it.matchingIndex,
-            it.idOfBaseResourceOnWhichThisMatchedInc ?: it.idOfBaseResourceOnWhichThisMatchedRev!!,
+            it.baseResourceUUID,
+            iParser.parseResource(it.serializedResource) as Resource,
+          )
+        }
+    }
+  }
+
+  override suspend fun searchReverseReferencedResources(
+    query: SearchQuery,
+  ): List<ReverseIncludeSearchResult> {
+    return db.withTransaction {
+      resourceDao
+        .getReverseReferencedResources(SimpleSQLiteQuery(query.query, query.args.toTypedArray()))
+        .map {
+          ReverseIncludeSearchResult(
+            it.matchingIndex,
+            it.baseResourceTypeAndId,
             iParser.parseResource(it.serializedResource) as Resource,
           )
         }

engine/src/main/java/com/google/android/fhir/db/impl/dao/ResourceDao.kt

@@ -226,12 +226,18 @@ internal abstract class ResourceDao {
     resourceUuid: UUID,
   ): ResourceEntity?
 
-  @RawQuery abstract suspend fun getResources(query: SupportSQLiteQuery): List<String>
+  @RawQuery
+  abstract suspend fun getResources(query: SupportSQLiteQuery): List<SerializedResourceWithUuid>
 
   @RawQuery
-  abstract suspend fun getReferencedResources(
+  abstract suspend fun getForwardReferencedResources(
     query: SupportSQLiteQuery,
-  ): List<IndexedIdAndSerializedResource>
+  ): List<ForwardIncludeSearchResponse>
+
+  @RawQuery
+  abstract suspend fun getReverseReferencedResources(
+    query: SupportSQLiteQuery,
+  ): List<ReverseIncludeSearchResponse>
 
   @RawQuery abstract suspend fun countResources(query: SupportSQLiteQuery): Long
 
@@ -411,23 +417,39 @@ internal abstract class ResourceDao {
   }
 }
 
-/**
- * Data class representing the value returned by [getReferencedResources]. The optional fields may
- * or may-not contain values based on the search query.
- */
-internal data class IndexedIdAndSerializedResource(
+internal class ForwardIncludeSearchResponse(
+  @ColumnInfo(name = "index_name") val matchingIndex: String,
+  @ColumnInfo(name = "resourceUuid") val baseResourceUUID: UUID,
+  val serializedResource: String,
+)
+
+internal class ReverseIncludeSearchResponse(
   @ColumnInfo(name = "index_name") val matchingIndex: String,
-  @ColumnInfo(name = "index_value") val idOfBaseResourceOnWhichThisMatchedRev: String?,
-  @ColumnInfo(name = "resourceId") val idOfBaseResourceOnWhichThisMatchedInc: String?,
+  @ColumnInfo(name = "index_value") val baseResourceTypeAndId: String,
   val serializedResource: String,
 )
 
 /**
- * Data class representing an included or revIncluded [Resource], index on which the match was done
- * and the id of the base [Resource] for which this [Resource] has been included.
+ * Data class representing a forward included [Resource], index on which the match was done and the
+ * uuid of the base [Resource] for which this [Resource] has been included.
  */
-internal data class IndexedIdAndResource(
-  val matchingIndex: String,
-  val idOfBaseResourceOnWhichThisMatched: String,
+internal data class ForwardIncludeSearchResult(
+  val searchIndex: String,
+  val baseResourceUUID: UUID,
   val resource: Resource,
 )
+
+/**
+ * Data class representing a reverse included [Resource], index on which the match was done and the
+ * type and logical id of the base [Resource] for which this [Resource] has been included.
+ */
+internal data class ReverseIncludeSearchResult(
+  val searchIndex: String,
+  val baseResourceTypeWithId: String,
+  val resource: Resource,
+)
+
+internal data class SerializedResourceWithUuid(
+  @ColumnInfo(name = "resourceUuid") val uuid: UUID,
+  val serializedResource: String,
+)