From 8129afdfcbfa09f4d9bf10d4441902751c1f50bb Mon Sep 17 00:00:00 2001
From: Aurangzaib Umer <aurangzaib.umer@venturedive.com>
Date: Fri, 23 Aug 2024 15:41:31 +0500
Subject: [PATCH] Caching questionnaires and their SM

---
 .../engine/task/FhirCarePlanGenerator.kt      |  2 +-
 .../quest/ui/questionnaire/ContentCache.kt    | 19 ++++++++++++
 .../questionnaire/QuestionnaireViewModel.kt   | 30 +++++++++++++++++--
 3 files changed, 48 insertions(+), 3 deletions(-)
 create mode 100644 android/quest/src/main/java/org/smartregister/fhircore/quest/ui/questionnaire/ContentCache.kt

diff --git a/android/engine/src/main/java/org/smartregister/fhircore/engine/task/FhirCarePlanGenerator.kt b/android/engine/src/main/java/org/smartregister/fhircore/engine/task/FhirCarePlanGenerator.kt
index 6fee7dfe88..44581b5db2 100644
--- a/android/engine/src/main/java/org/smartregister/fhircore/engine/task/FhirCarePlanGenerator.kt
+++ b/android/engine/src/main/java/org/smartregister/fhircore/engine/task/FhirCarePlanGenerator.kt
@@ -214,7 +214,7 @@ constructor(
               }
             source.setParameter(Task.SP_PERIOD, period)
             source.setParameter(ActivityDefinition.SP_VERSION, IntegerType(index))
-
+            //need to cache these SM too
             val structureMap = fhirEngine.get<StructureMap>(IdType(action.transform).idPart)
             structureMapUtilities.transform(
               transformSupportServices.simpleWorkerContext,
diff --git a/android/quest/src/main/java/org/smartregister/fhircore/quest/ui/questionnaire/ContentCache.kt b/android/quest/src/main/java/org/smartregister/fhircore/quest/ui/questionnaire/ContentCache.kt
new file mode 100644
index 0000000000..e92f201555
--- /dev/null
+++ b/android/quest/src/main/java/org/smartregister/fhircore/quest/ui/questionnaire/ContentCache.kt
@@ -0,0 +1,19 @@
+package org.smartregister.fhircore.quest.ui.questionnaire
+
+import androidx.collection.LruCache
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import org.hl7.fhir.r4.model.Resource
+
+object ContentCache {
+    private val maxMemory: Int = (Runtime.getRuntime().maxMemory() / 1024).toInt()
+    private val cacheSize: Int = maxMemory / 8
+    private val cache = LruCache<String, Resource>(cacheSize)
+
+    suspend fun saveResource(resourceId: String, resource: Resource) =
+        withContext(Dispatchers.IO) { cache.put("${resource::class.simpleName}/$resourceId", resource) }
+
+    fun getResource(resourceId: String) = cache[resourceId]
+
+    suspend fun invalidate() = withContext(Dispatchers.IO) { cache.evictAll() }
+}
\ No newline at end of file
diff --git a/android/quest/src/main/java/org/smartregister/fhircore/quest/ui/questionnaire/QuestionnaireViewModel.kt b/android/quest/src/main/java/org/smartregister/fhircore/quest/ui/questionnaire/QuestionnaireViewModel.kt
index 12c43c1dc3..a955bc0fe5 100644
--- a/android/quest/src/main/java/org/smartregister/fhircore/quest/ui/questionnaire/QuestionnaireViewModel.kt
+++ b/android/quest/src/main/java/org/smartregister/fhircore/quest/ui/questionnaire/QuestionnaireViewModel.kt
@@ -61,6 +61,7 @@ import org.hl7.fhir.r4.model.QuestionnaireResponse.QuestionnaireResponseItemComp
 import org.hl7.fhir.r4.model.RelatedPerson
 import org.hl7.fhir.r4.model.Resource
 import org.hl7.fhir.r4.model.ResourceType
+import org.hl7.fhir.r4.model.StructureMap
 import org.smartregister.fhircore.engine.BuildConfig
 import org.smartregister.fhircore.engine.configuration.ConfigType
 import org.smartregister.fhircore.engine.configuration.ConfigurationRegistry
@@ -146,7 +147,18 @@ constructor(
     questionnaireConfig: QuestionnaireConfig,
   ): Questionnaire? {
     if (questionnaireConfig.id.isEmpty() || questionnaireConfig.id.isBlank()) return null
-    return defaultRepository.loadResource<Questionnaire>(questionnaireConfig.id)
+    var questionnaire = ContentCache.getResource(ResourceType.Questionnaire.name + "/" + questionnaireConfig.id)?.copy()
+    if (questionnaire == null) {
+      questionnaire = defaultRepository.loadResource<Questionnaire>(questionnaireConfig.id)?.also { ques ->
+        ContentCache.saveResource(
+          questionnaireConfig.id,
+          ques.copy(),
+        )
+      }
+    }
+
+
+    return questionnaire as Questionnaire
   }
 
   /**
@@ -631,7 +643,7 @@ constructor(
                 transformSupportServices = transformSupportServices,
                 structureMapProvider = { structureMapUrl: String?, _: IWorkerContext ->
                   structureMapUrl?.substringAfterLast("/")?.let {
-                    defaultRepository.loadResource(it)
+                   fetchStructureMap(it)
                   }
                 },
               ),
@@ -661,6 +673,20 @@ constructor(
       }
       .getOrDefault(Bundle())
 
+
+  private suspend fun fetchStructureMap(structureMapUrl: String?): StructureMap? {
+    var structureMap: Resource? = null
+    structureMapUrl?.substringAfterLast("/")?.run {
+      structureMap = ContentCache.getResource(ResourceType.StructureMap.name + "/" + this) ?.let {
+        defaultRepository.loadResource<StructureMap>(this)?.also {
+          it.let { ContentCache.saveResource(this, it) }
+        }
+      }
+    }
+    return structureMap as StructureMap?
+  }
+
+
   /**
    * This function saves [QuestionnaireResponse] as draft if any of the [QuestionnaireResponse.item]
    * has an answer.