refactor: update PayPalEnvironment to use sealed class

demo/src/main/java/com/paypal/messagesdemo/XmlActivity.kt

@@ -205,6 +205,5 @@ class XmlActivity : AppCompatActivity() {
 		message.onLoading = {}
 		message.onSuccess = {}
 		message.onError = {}
-		EnvVars.getClientId(PayPalEnvironment.STAGE)
 	}
 }

library/src/main/java/com/paypal/messages/config/PayPalEnvironment.kt

@@ -3,45 +3,34 @@ package com.paypal.messages.config
 import okhttp3.HttpUrl
 import okhttp3.HttpUrl.Companion.toHttpUrl
 
-enum class PayPalEnvironment {
-	LOCAL,
-	STAGE,
-	SANDBOX,
-	LIVE,
-	;
-
-	val isProduction: Boolean
-		get() = this == LIVE || this == SANDBOX
-
-	private var host: String? = null
-	private var port: Int? = null
+sealed class PayPalEnvironment {
+	abstract val presentmentUrl: String
+	abstract val loggerBaseUrl: String
+	abstract val isProduction: Boolean
+
+	class LocalEnvironment(port: Int) : PayPalEnvironment() {
+		override val presentmentUrl = "http://localhost:$port"
+		override val loggerBaseUrl = presentmentUrl
+		override val isProduction = false
+	}
 
-	companion object {
-		fun local(port: Int = 8443): PayPalEnvironment {
-			LOCAL.port = port
-			return LOCAL
-		}
-		fun stage(host: String): PayPalEnvironment {
-			STAGE.host = host
-			return STAGE
-		}
+	class StageEnvironment(host: String) : PayPalEnvironment() {
+		override val presentmentUrl = "https://www.$host"
+		override val loggerBaseUrl = "https://api.$host"
+		override val isProduction = false
 	}
 
-	private val presentmentUrl: String
-		get() = when (this) {
-			LOCAL -> "http://localhost:$port"
-			STAGE -> "https://www.$host"
-			SANDBOX -> "https://www.sandbox.paypal.com"
-			LIVE -> "https://www.paypal.com"
-		}
+	class SandboxEnvironment : PayPalEnvironment() {
+		override val presentmentUrl = "https://www.sandbox.paypal.com"
+		override val loggerBaseUrl = "https://api.sandbox.paypal.com"
+		override val isProduction = true
+	}
 
-	private val loggerBaseUrl: String
-		get() = when (this) {
-			LOCAL -> presentmentUrl
-			STAGE -> "https://api.$host"
-			SANDBOX -> "https://api.sandbox.paypal.com"
-			LIVE -> "https://api.paypal.com"
-		}
+	class LiveEnvironment : PayPalEnvironment() {
+		override val presentmentUrl = "https://www.paypal.com"
+		override val loggerBaseUrl = "https://api.paypal.com"
+		override val isProduction = true
+	}
 
 	enum class Endpoints(val path: String) {
 		MESSAGE_DATA("credit-presentment/native/message"),
@@ -54,4 +43,18 @@ enum class PayPalEnvironment {
 		val baseUrl = if (endpoint === Endpoints.LOGGER) loggerBaseUrl else presentmentUrl
 		return "$baseUrl/${endpoint.path}".toHttpUrl()
 	}
+
+	@Suppress("FunctionName")
+	companion object {
+		fun LOCAL(port: Int = 8443): LocalEnvironment {
+			return LocalEnvironment(port)
+		}
+
+		fun STAGE(host: String): StageEnvironment {
+			return StageEnvironment(host)
+		}
+
+		val SANDBOX = SandboxEnvironment()
+		val LIVE = LiveEnvironment()
+	}
 }

library/src/main/java/com/paypal/messages/io/Api.kt

@@ -29,7 +29,7 @@ object Api {
 	// if connecting to a test environment, use ApiClient.insecureClient
 	private val client = ApiClient.secureClient
 	private val gson = GsonBuilder().setPrettyPrinting().create()
-	var env = Env.SANDBOX
+	var env: Env = Env.SANDBOX
 	var devTouchpoint: Boolean = false
 	var ignoreCache: Boolean = false
 	var stageTag: String? = null