server: Add endpoint "GET /blocks/estimate-fee"

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

@@ -7,7 +7,7 @@ import com.alexitc.playsonify.models.pagination.{Limit, Offset, PaginatedQuery}
 import com.alexitc.playsonify.validators.PaginatedQueryValidator
 import com.xsn.explorer.cache.BlockHeaderCache
 import com.xsn.explorer.data.async.BlockFutureDataHandler
-import com.xsn.explorer.errors.BlockRewardsNotFoundError
+import com.xsn.explorer.errors.{BlockRewardsNotFoundError, XSNMessageError}
 import com.xsn.explorer.models._
 import com.xsn.explorer.models.persisted.BlockHeader
 import com.xsn.explorer.models.rpc.{Block, TransactionVIN}
@@ -159,6 +159,15 @@ class BlockService @Inject() (
     }
   }
 
+  def estimateFee(nBlocks: Int): FutureApplicationResult[JsValue] = {
+    if (nBlocks >= 1 && nBlocks <= 1000) {
+      xsnService.estimateSmartFee(nBlocks)
+    } else {
+      val error = XSNMessageError("The nBlocks should be between 1 and 1000")
+      Future.successful(Bad(error).accumulating)
+    }
+  }
+
   private def isPoS(block: rpc.Block): FutureApplicationResult[Boolean] = {
     val result = for {
       coinbaseTxid <- blockLogic.getCoinbase(block).toFutureOr

server/app/controllers/BlocksController.scala

@@ -60,6 +60,10 @@ class BlocksController @Inject() (
   def getLightTransactionsV2(blockhash: String, limit: Int, lastSeenTxid: Option[String]) = public { _ =>
     transactionService.getLightWalletTransactionsByBlockhash(blockhash, Limit(limit), lastSeenTxid)
   }
+
+  def estimateFee(nBlocks: Int) = public { _ =>
+    blockService.estimateFee(nBlocks)
+  }
 }
 
 object BlocksController {

server/conf/routes

@@ -18,6 +18,7 @@ GET   /addresses/:address/utxos                      controllers.AddressesContro
 
 GET   /blocks                            controllers.BlocksController.getLatestBlocks()
 GET   /blocks/headers                    controllers.BlocksController.getBlockHeaders(lastSeenHash: Option[String], limit: Int ?= 10, order: String ?= "asc")
+GET   /blocks/estimate-fee               controllers.BlocksController.estimateFee(nBlocks: Int ?= 1)
 
 GET   /blocks/:query                     controllers.BlocksController.getDetails(query: String)
 GET   /blocks/:query/raw                 controllers.BlocksController.getRawBlock(query: String)