server: Add support for storing the genesis block (#39)

server/app/com/xsn/explorer/services/XSNService.scala

@@ -47,12 +47,27 @@ trait XSNService {
   def sendRawTransaction(hex: HexString): FutureApplicationResult[Unit]
 }
 
+object XSNService {
+
+  val GenesisBlockhash: Blockhash = Blockhash.from("00000c822abdbb23e28f79a49d29b41429737c6c7e15df40d1b1f1b35907ae34").get
+
+  def cleanGenesisBlock(block: rpc.Block): rpc.Block = {
+    // the genesis transaction is not available, see https://github.com/X9Developers/XSN/issues/32
+    Option(block)
+        .filter(_.hash == GenesisBlockhash)
+        .map(_.copy(transactions = List.empty))
+        .getOrElse(block)
+  }
+}
+
 class XSNServiceRPCImpl @Inject() (
     ws: WSClient,
     rpcConfig: RPCConfig)(
     implicit ec: ExternalServiceExecutionContext)
     extends XSNService {
 
+  import XSNService._
+
   private val logger = LoggerFactory.getLogger(this.getClass)
 
   private val server = ws.url(rpcConfig.host.string)
@@ -155,7 +170,12 @@ class XSNServiceRPCImpl @Inject() (
         .map { response =>
 
           val maybe = getResult[rpc.Block](response, errorCodeMapper)
-          maybe.getOrElse {
+          maybe
+              .map {
+                case Good(block) => Good(cleanGenesisBlock(block))
+                case x => x
+              }
+              .getOrElse {
             logger.warn(s"Unexpected response from XSN Server, txid = ${blockhash.string}, status = ${response.status}, response = ${response.body}")
 
             Bad(XSNUnexpectedResponseError).accumulating
@@ -219,7 +239,12 @@ class XSNServiceRPCImpl @Inject() (
                 .getOrElse(Bad(XSNUnexpectedResponseError).accumulating)
                 .toFutureOr
 
-            block <- getBlock(blockhash).toFutureOr
+            block <- getBlock(blockhash).
+                map {
+                  case Good(block) => Good(cleanGenesisBlock(block))
+                  case x => x
+                }
+                .toFutureOr
           } yield block
 
           result.toFuture

server/test/com/xsn/explorer/helpers/BlockLoader.scala

@@ -3,6 +3,7 @@ package com.xsn.explorer.helpers
 import java.io.File
 
 import com.xsn.explorer.models.rpc.Block
+import com.xsn.explorer.services.XSNService
 import play.api.libs.json.{JsValue, Json}
 
 object BlockLoader {
@@ -10,7 +11,8 @@ object BlockLoader {
   private val BasePath = "blocks"
 
   def get(blockhash: String): Block = {
-    json(blockhash).as[Block]
+    val block = json(blockhash).as[Block]
+    XSNService.cleanGenesisBlock(block)
   }
 
   def json(blockhash: String): JsValue = {

server/test/com/xsn/explorer/services/XSNServiceRPCImplSpec.scala

@@ -293,6 +293,26 @@ class XSNServiceRPCImplSpec extends WordSpec with MustMatchers with ScalaFutures
   }
 
   "getBlock" should {
+    "return the genesis block" in {
+      val block = BlockLoader.json("00000c822abdbb23e28f79a49d29b41429737c6c7e15df40d1b1f1b35907ae34")
+      val responseBody = createRPCSuccessfulResponse(block)
+      val blockhash = Blockhash.from("00000c822abdbb23e28f79a49d29b41429737c6c7e15df40d1b1f1b35907ae34").get
+
+      val json = Json.parse(responseBody)
+
+      when(response.status).thenReturn(200)
+      when(response.json).thenReturn(json)
+      when(request.post[String](anyString())(any())).thenReturn(Future.successful(response))
+
+      whenReady(service.getBlock(blockhash)) { result =>
+        result.isGood mustEqual true
+
+        val block = result.get
+        block.hash mustEqual blockhash
+        block.transactions mustEqual List.empty
+      }
+    }
+
     "return a block" in {
       val block = BlockLoader.json("b72dd1655408e9307ef5874be20422ee71029333283e2360975bc6073bdb2b81")
       val responseBody = createRPCSuccessfulResponse(block)