make enrichment closure a property of event

Author: wenxi-zeng

core/src/main/java/com/segment/analytics/kotlin/core/Analytics.kt

@@ -513,9 +513,9 @@ open class Analytics protected constructor(
 
         log("applying base attributes on ${Thread.currentThread().name}")
         analyticsScope.launch(analyticsDispatcher) {
-            event.applyBaseEventData(store)
+            event.applyBaseEventData(store, enrichment)
             log("processing event on ${Thread.currentThread().name}")
-            timeline.process(event, enrichment)
+            timeline.process(event)
         }
     }
 

core/src/main/java/com/segment/analytics/kotlin/core/Events.kt

@@ -12,6 +12,7 @@ typealias AnalyticsContext = JsonObject
 typealias Integrations = JsonObject
 typealias Properties = JsonObject
 typealias Traits = JsonObject
+typealias EnrichmentClosure = (event: BaseEvent?) -> BaseEvent?
 
 val emptyJsonObject = JsonObject(emptyMap())
 val emptyJsonArray = JsonArray(emptyList())
@@ -75,6 +76,8 @@ sealed class BaseEvent {
 
     abstract var _metadata: DestinationMetadata
 
+    var enrichment: EnrichmentClosure? = null
+
     companion object {
         internal const val ALL_INTEGRATIONS_KEY = "All"
     }
@@ -85,9 +88,10 @@ sealed class BaseEvent {
         this.messageId = UUID.randomUUID().toString()
     }
 
-    internal suspend fun applyBaseEventData(store: Store) {
+    internal suspend fun applyBaseEventData(store: Store, enrichment: EnrichmentClosure?) {
         val userInfo = store.currentState(UserInfo::class) ?: return
 
+        this.enrichment = enrichment
         this.anonymousId = userInfo.anonymousId
         this.integrations = emptyJsonObject
 

core/src/main/java/com/segment/analytics/kotlin/core/platform/Timeline.kt

@@ -24,10 +24,10 @@ internal class Timeline {
     lateinit var analytics: Analytics
 
     // initiate the event's lifecycle
-    fun process(incomingEvent: BaseEvent, enrichmentClosure: EnrichmentClosure? = null): BaseEvent? {
+    fun process(incomingEvent: BaseEvent): BaseEvent? {
         val beforeResult = applyPlugins(Plugin.Type.Before, incomingEvent)
         var enrichmentResult = applyPlugins(Plugin.Type.Enrichment, beforeResult)
-        enrichmentClosure?.let {
+        enrichmentResult?.enrichment?.let {
             enrichmentResult = it(enrichmentResult)
         }
 

core/src/main/java/com/segment/analytics/kotlin/core/platform/plugins/StartupQueue.kt

@@ -72,7 +72,7 @@ class StartupQueue : Plugin, Subscriber {
             // after checking if the queue is empty so we only process if the event
             // if it is indeed not NULL.
             event?.let {
-                analytics.process(it)
+                analytics.process(it, it.enrichment)
             }
         }
     }