SegmentDestination refactor and add cdnHost config option (#34)

* refactory SegmentDestination.kt

* fix failing tests

* add cdn host to ConfigurationBuilder.kt

* update tests

Author: prayansh

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

@@ -4,6 +4,7 @@ import com.segment.analytics.kotlin.core.platform.DestinationPlugin
 import com.segment.analytics.kotlin.core.platform.Plugin
 import com.segment.analytics.kotlin.core.platform.Timeline
 import com.segment.analytics.kotlin.core.platform.plugins.ContextPlugin
+import com.segment.analytics.kotlin.core.platform.plugins.SegmentDestination
 import com.segment.analytics.kotlin.core.platform.plugins.StartupQueue
 import com.segment.analytics.kotlin.core.platform.plugins.log
 import kotlinx.coroutines.CoroutineDispatcher

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

@@ -1,5 +1,7 @@
 package com.segment.analytics.kotlin.core
 
+import com.segment.analytics.kotlin.core.Constants.DEFAULT_API_HOST
+import com.segment.analytics.kotlin.core.Constants.DEFAULT_CDN_HOST
 import com.segment.analytics.kotlin.core.utilities.ConcreteStorageProvider
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.CoroutineScope
@@ -42,7 +44,8 @@ data class Configuration(
     var flushInterval: Int = 30,
     val defaultSettings: Settings = Settings(),
     var autoAddSegmentDestination: Boolean = true,
-    var apiHost: String = "api.segment.io/v1"
+    var apiHost: String = DEFAULT_API_HOST,
+    var cdnHost: String = DEFAULT_CDN_HOST
 ) {
     fun isValid(): Boolean {
         return writeKey.isNotBlank() && application != null

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

@@ -2,4 +2,6 @@ package com.segment.analytics.kotlin.core
 
 object Constants {
     const val LIBRARY_VERSION = "1.2.0"
+    const val DEFAULT_API_HOST = "api.segment.io/v1"
+    const val DEFAULT_CDN_HOST = "cdn-settings.segment.com/v1"
 }

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

@@ -15,9 +15,9 @@ import java.util.zip.GZIPOutputStream
 class HTTPClient(private val writeKey: String) {
     internal val authHeader = authorizationHeader(writeKey)
 
-    fun settings(): Connection {
+    fun settings(cdnHost: String): Connection {
         val connection: HttpURLConnection =
-            openConnection("https://cdn-settings.segment.com/v1/projects/$writeKey/settings")
+            openConnection("https://$cdnHost/projects/$writeKey/settings")
         val responseCode = connection.responseCode
         if (responseCode != HttpURLConnection.HTTP_OK) {
             connection.disconnect()

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

@@ -51,14 +51,15 @@ internal fun Analytics.update(settings: Settings, type: Plugin.UpdateType) {
  */
 fun Analytics.checkSettings() {
     val writeKey = configuration.writeKey
+    val cdnHost = configuration.cdnHost
 
     // stop things; queue in case our settings have changed.
     store.dispatch(System.ToggleRunningAction(running = false), System::class)
 
     analyticsScope.launch(ioDispatcher) {
         log("Fetching settings on ${Thread.currentThread().name}")
         val settingsObj: Settings? = try {
-            val connection = HTTPClient(writeKey).settings()
+            val connection = HTTPClient(writeKey).settings(cdnHost)
             val settingsString =
                 connection.inputStream?.bufferedReader()?.use(BufferedReader::readText) ?: ""
             log("Fetched Settings: $settingsString")

core/src/main/java/com/segment/analytics/kotlin/core/compat/ConfigurationBuilder.kt

@@ -38,5 +38,7 @@ class ConfigurationBuilder (writeKey: String) {
 
     fun setApiHost(apiHost: String) = apply { configuration.apiHost = apiHost}
 
+    fun setCdnHost(cdnHost: String) = apply { configuration.cdnHost = cdnHost}
+
     fun build() = configuration
 }

core/src/main/java/com/segment/analytics/kotlin/core/SegmentDestination.kt renamed to core/src/main/java/com/segment/analytics/kotlin/core/platform/plugins/SegmentDestination.kt

@@ -1,11 +1,24 @@
-package com.segment.analytics.kotlin.core
-
+package com.segment.analytics.kotlin.core.platform.plugins
+
+import com.segment.analytics.kotlin.core.AliasEvent
+import com.segment.analytics.kotlin.core.Analytics
+import com.segment.analytics.kotlin.core.BaseEvent
+import com.segment.analytics.kotlin.core.Constants.DEFAULT_API_HOST
+import com.segment.analytics.kotlin.core.GroupEvent
+import com.segment.analytics.kotlin.core.HTTPClient
+import com.segment.analytics.kotlin.core.HTTPException
+import com.segment.analytics.kotlin.core.IdentifyEvent
+import com.segment.analytics.kotlin.core.ScreenEvent
+import com.segment.analytics.kotlin.core.Settings
+import com.segment.analytics.kotlin.core.Storage
+import com.segment.analytics.kotlin.core.TrackEvent
+import com.segment.analytics.kotlin.core.emptyJsonObject
+import com.segment.analytics.kotlin.core.parseFilePaths
 import com.segment.analytics.kotlin.core.platform.DestinationPlugin
 import com.segment.analytics.kotlin.core.platform.Plugin
-import com.segment.analytics.kotlin.core.platform.plugins.LogType
-import com.segment.analytics.kotlin.core.platform.plugins.log
 import com.segment.analytics.kotlin.core.utilities.EncodeDefaultsJson
 import kotlinx.coroutines.launch
+import kotlinx.serialization.Serializable
 import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
 import kotlinx.serialization.json.encodeToJsonElement
@@ -19,6 +32,12 @@ import java.util.concurrent.ScheduledExecutorService
 import java.util.concurrent.TimeUnit
 import java.util.concurrent.atomic.AtomicInteger
 
+@Serializable
+data class SegmentSettings(
+    var apiKey: String,
+    var apiHost: String = DEFAULT_API_HOST,
+)
+
 /**
  * Segment Analytics plugin that is used to send events to Segment's tracking api, in the choice of region.
  * How it works
@@ -30,7 +49,7 @@ class SegmentDestination(
     private var apiKey: String,
     private val flushCount: Int = 20,
     private val flushIntervalInMillis: Long = 30 * 1000, // 30s
-    private var apiHost: String = "api.segment.io/v1"
+    private var apiHost: String = DEFAULT_API_HOST
 ) : DestinationPlugin() {
 
     override val key: String = "Segment.io"
@@ -66,10 +85,11 @@ class SegmentDestination(
 
     private inline fun <reified T : BaseEvent> enqueue(payload: T) {
         // needs to be inline reified for encoding using Json
-        val jsonVal = EncodeDefaultsJson.encodeToJsonElement(payload).jsonObject.filterNot { (k, v) ->
-            // filter out empty userId and traits values
-            (k == "userId" && v.jsonPrimitive.content.isBlank()) || (k == "traits" && v == emptyJsonObject)
-        }
+        val jsonVal = EncodeDefaultsJson.encodeToJsonElement(payload)
+            .jsonObject.filterNot { (k, v) ->
+                // filter out empty userId and traits values
+                (k == "userId" && v.jsonPrimitive.content.isBlank()) || (k == "traits" && v == emptyJsonObject)
+            }
 
         val stringVal = Json.encodeToString(jsonVal)
         analytics.log("$key running $stringVal")
@@ -109,9 +129,11 @@ class SegmentDestination(
     }
 
     override fun update(settings: Settings, type: Plugin.UpdateType) {
-        settings.integrations[key]?.jsonObject?.let {
-            apiKey = it["apiKey"]?.jsonPrimitive?.content ?: apiKey
-            apiHost = it["apiHost"]?.jsonPrimitive?.content ?: apiHost
+        if (settings.isDestinationEnabled(key)) {
+            settings.destinationSettings<SegmentSettings>(key)?.let {
+                apiKey = it.apiKey
+                apiHost = it.apiHost
+            }
         }
     }
 

core/src/test/kotlin/com/segment/analytics/kotlin/core/HTTPClientTests.kt

@@ -22,7 +22,7 @@ class HTTPClientTests {
 
     @Test
     fun `upload connection has correct configuration`() {
-        httpClient.settings().connection.let {
+        httpClient.settings("cdn-settings.segment.com/v1").connection.let {
             assertEquals(
                 "https://cdn-settings.segment.com/v1/projects/1vNgUqwJeCHmqgI9S1sOm9UHCyfYqbaQ/settings",
                 it.url.toString()

core/src/test/kotlin/com/segment/analytics/kotlin/core/SegmentDestinationTests.kt

@@ -2,6 +2,7 @@ package com.segment.analytics.kotlin.core
 
 import com.segment.analytics.kotlin.core.platform.plugins.LogType
 import com.segment.analytics.kotlin.core.platform.plugins.Logger
+import com.segment.analytics.kotlin.core.platform.plugins.SegmentDestination
 import com.segment.analytics.kotlin.core.utilities.ConcreteStorageProvider
 import com.segment.analytics.kotlin.core.utilities.EncodeDefaultsJson
 import com.segment.analytics.kotlin.core.utilities.StorageImpl

core/src/test/kotlin/com/segment/analytics/kotlin/core/SettingsTests.kt

@@ -34,7 +34,7 @@ class SettingsTests {
         )
         val httpConnection: HttpURLConnection = mockk()
         val connection = object : Connection(httpConnection, settingsStream, null) {}
-        every { anyConstructed<HTTPClient>().settings() } returns connection
+        every { anyConstructed<HTTPClient>().settings("cdn-settings.segment.com/v1") } returns connection
     }
 
     @BeforeEach
@@ -55,7 +55,7 @@ class SettingsTests {
     fun `checkSettings updates settings`() = runBlocking {
         val system = analytics.store.currentState(System::class)
         val curSettings = system?.settings
-        Assertions.assertEquals(
+        assertEquals(
             Settings(
                 integrations = buildJsonObject {
                     put(