Update the version of resource after updates are downloaded from the server

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 Google LLC
+ * Copyright 2022-2023 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -57,7 +57,7 @@ fun <R : Resource> getResourceClass(resourceType: String): Class<R> {
   return Class.forName(R4_RESOURCE_PACKAGE_PREFIX + className) as Class<R>
 }
 
-internal val Resource.versionId
+internal val Resource.versionId: String?
   get() = meta.versionId
 
 internal val Resource.lastUpdated

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

@@ -140,7 +140,7 @@ internal class DatabaseImpl(
       resources.forEach {
         val timeOfLocalChange = Instant.now()
         val oldResourceEntity = selectEntity(it.resourceType, it.logicalId)
-        resourceDao.update(it, timeOfLocalChange)
+        resourceDao.updateLocalChange(it, timeOfLocalChange)
         localChangeDao.addUpdate(oldResourceEntity, it, timeOfLocalChange)
       }
     }

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

@@ -58,42 +58,57 @@ internal abstract class ResourceDao {
   lateinit var iParser: IParser
   lateinit var resourceIndexer: ResourceIndexer
 
-  open suspend fun update(resource: Resource, timeOfLocalChange: Instant?) {
+  open suspend fun updateLocalChange(resource: Resource, timeOfLocalChange: Instant?) {
     getResourceEntity(resource.logicalId, resource.resourceType)?.let {
-      // In case the resource has lastUpdated meta data, use it, otherwise use the old value.
-      val lastUpdatedRemote: Date? = resource.meta.lastUpdated
       val entity =
         it.copy(
           serializedResource = iParser.encodeResourceToString(resource),
           lastUpdatedLocal = timeOfLocalChange,
-          lastUpdatedRemote = lastUpdatedRemote?.toInstant() ?: it.lastUpdatedRemote,
         )
-      // The foreign key in Index entity tables is set with cascade delete constraint and
-      // insertResource has REPLACE conflict resolution. So, when we do an insert to update the
-      // resource, it deletes old resource and corresponding index entities (based on foreign key
-      // constrain) before inserting the new resource.
-      insertResource(entity)
-      val index =
-        ResourceIndices.Builder(resourceIndexer.index(resource))
-          .apply {
-            timeOfLocalChange?.let {
-              addDateTimeIndex(
-                createLocalLastUpdatedIndex(
-                  resource.resourceType,
-                  InstantType(Date.from(timeOfLocalChange)),
-                ),
-              )
-            }
-            lastUpdatedRemote?.let { date ->
-              addDateTimeIndex(createLastUpdatedIndex(resource.resourceType, InstantType(date)))
-            }
-          }
-          .build()
-      updateIndicesForResource(index, resource.resourceType, it.resourceUuid)
+      updateChanges(entity, resource)
+    }
+      ?: throw ResourceNotFoundException(resource.resourceType.name, resource.id)
+  }
+
+  open suspend fun updateRemoteChange(resource: Resource) {
+    getResourceEntity(resource.logicalId, resource.resourceType)?.let {
+      val lastUpdatedRemote: Date? = resource.meta.lastUpdated
+      val entity =
+        it.copy(
+          serializedResource = iParser.encodeResourceToString(resource),
+          lastUpdatedRemote = lastUpdatedRemote?.toInstant(),
+          versionId = resource.versionId,
+        )
+      updateChanges(entity, resource)
     }
       ?: throw ResourceNotFoundException(resource.resourceType.name, resource.id)
   }
 
+  // WARNING : This is a private function and shouldn't be called directly.
+  open suspend fun updateChanges(entity: ResourceEntity, resource: Resource) {
+    // The foreign key in Index entity tables is set with cascade delete constraint and
+    // insertResource has REPLACE conflict resolution. So, when we do an insert to update the
+    // resource, it deletes old resource and corresponding index entities (based on foreign key
+    // constrain) before inserting the new resource.
+    insertResource(entity)
+    val index =
+      ResourceIndices.Builder(resourceIndexer.index(resource))
+        .apply {
+          entity.lastUpdatedLocal?.let { instant ->
+            addDateTimeIndex(
+              createLocalLastUpdatedIndex(resource.resourceType, InstantType(Date.from(instant))),
+            )
+          }
+          entity.lastUpdatedRemote?.let { instant ->
+            addDateTimeIndex(
+              createLastUpdatedIndex(resource.resourceType, InstantType(Date.from(instant))),
+            )
+          }
+        }
+        .build()
+    updateIndicesForResource(index, resource.resourceType, entity.resourceUuid)
+  }
+
   open suspend fun insertAllRemote(resources: List<Resource>): List<UUID> {
     return resources.map { resource -> insertRemoteResource(resource) }
   }
@@ -189,7 +204,7 @@ internal abstract class ResourceDao {
   private suspend fun insertRemoteResource(resource: Resource): UUID {
     val existingResourceEntity = getResourceEntity(resource.logicalId, resource.resourceType)
     if (existingResourceEntity != null) {
-      update(resource, existingResourceEntity.lastUpdatedLocal)
+      updateRemoteChange(resource)
       return existingResourceEntity.resourceUuid
     }
     return insertResource(resource, null)

engine/src/test/java/com/google/android/fhir/impl/FhirEngineImplTest.kt

@@ -24,6 +24,7 @@ import com.google.android.fhir.LocalChange.Type
 import com.google.android.fhir.LocalChangeToken
 import com.google.android.fhir.db.ResourceNotFoundException
 import com.google.android.fhir.get
+import com.google.android.fhir.lastUpdated
 import com.google.android.fhir.logicalId
 import com.google.android.fhir.search.LOCAL_LAST_UPDATED_PARAM
 import com.google.android.fhir.search.search
@@ -36,7 +37,9 @@ import com.google.android.fhir.sync.upload.UploadSyncResult
 import com.google.android.fhir.testing.assertResourceEquals
 import com.google.android.fhir.testing.assertResourceNotEquals
 import com.google.android.fhir.testing.readFromFile
+import com.google.android.fhir.versionId
 import com.google.common.truth.Truth.assertThat
+import java.time.Instant
 import java.util.Date
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.flowOf
@@ -592,6 +595,87 @@ class FhirEngineImplTest {
       assertResourceEquals(fhirEngine.get<Patient>("original-002"), localChange)
     }
 
+  @Test
+  fun `syncDownload ResourceEntity should have the latest versionId and lastUpdated from server`() =
+    runBlocking {
+      val originalPatient =
+        Patient().apply {
+          id = "original-002"
+          meta =
+            Meta().apply {
+              versionId = "1"
+              lastUpdated = Date.from(Instant.parse("2022-12-02T10:15:30.00Z"))
+            }
+          addName(
+            HumanName().apply {
+              family = "Stark"
+              addGiven("Tony")
+            },
+          )
+        }
+      // First sync
+      fhirEngine.syncDownload(AcceptLocalConflictResolver) { flowOf((listOf((originalPatient)))) }
+
+      val remoteChange =
+        originalPatient.copy().apply {
+          meta =
+            Meta().apply {
+              versionId = "2"
+              lastUpdated = Date.from(Instant.parse("2022-12-03T10:15:30.00Z"))
+            }
+          addAddress(Address().apply { country = "USA" })
+        }
+
+      // Sync to get updates from server
+      fhirEngine.syncDownload(AcceptLocalConflictResolver) { flowOf((listOf(remoteChange))) }
+
+      val result = services.database.selectEntity(ResourceType.Patient, "original-002")
+      assertThat(result.versionId).isEqualTo(remoteChange.versionId)
+      assertThat(result.lastUpdatedRemote).isEqualTo(remoteChange.lastUpdated)
+    }
+
+  @Test
+  fun `syncDownload LocalChangeEntity should have the latest versionId from server`() =
+    runBlocking {
+      val originalPatient =
+        Patient().apply {
+          id = "original-002"
+          meta =
+            Meta().apply {
+              versionId = "1"
+              lastUpdated = Date.from(Instant.parse("2022-12-02T10:15:30.00Z"))
+            }
+          addName(
+            HumanName().apply {
+              family = "Stark"
+              addGiven("Tony")
+            },
+          )
+        }
+      // First sync
+      fhirEngine.syncDownload(AcceptLocalConflictResolver) { flowOf((listOf((originalPatient)))) }
+
+      val localChange =
+        originalPatient.copy().apply { addAddress(Address().apply { city = "Malibu" }) }
+      fhirEngine.update(localChange)
+
+      val remoteChange =
+        originalPatient.copy().apply {
+          meta =
+            Meta().apply {
+              versionId = "2"
+              lastUpdated = Date.from(Instant.parse("2022-12-03T10:15:30.00Z"))
+            }
+          addAddress(Address().apply { country = "USA" })
+        }
+
+      // Sync to get updates from server
+      fhirEngine.syncDownload(AcceptLocalConflictResolver) { flowOf((listOf(remoteChange))) }
+
+      val result = fhirEngine.getLocalChanges(ResourceType.Patient, "original-002").first()
+      assertThat(result.versionId).isEqualTo(remoteChange.versionId)
+    }
+
   @Test
   fun `create should allow patient search with LOCAL_LAST_UPDATED_PARAM`(): Unit = runBlocking {
     val patient = Patient().apply { id = "patient-id-create" }