server: Synchronize the TPoS contracts

- A TPoS contract is created when the transaction is synchronized.
- A TPoS contract is deleted when the transaction is rolled back.
- A TPoS contract is closed when the collateral output is spent.
- A TPoS contract is enabled when the collateral output gets unspent.

server/app/com/xsn/explorer/data/LedgerDataHandler.scala

@@ -1,6 +1,7 @@
 package com.xsn.explorer.data
 
 import com.alexitc.playsonify.core.ApplicationResult
+import com.xsn.explorer.models.TPoSContract
 import com.xsn.explorer.models.persisted.Block
 
 import scala.language.higherKinds
@@ -16,7 +17,7 @@ trait LedgerDataHandler[F[_]] {
    * - The ledger is empty and the block is the genesis one.
    * - The ledger has some blocks and the block goes just after the latest one.
    */
-  def push(block: Block.HasTransactions): F[Unit]
+  def push(block: Block.HasTransactions, tposContracts: List[TPoSContract]): F[Unit]
 
   /**
    * Remove the latest block from the ledger, it will succeed only if the ledger is not empty.

server/app/com/xsn/explorer/data/anorm/LedgerPostgresDataHandler.scala

@@ -8,6 +8,7 @@ import com.xsn.explorer.data.LedgerBlockingDataHandler
 import com.xsn.explorer.data.anorm.dao._
 import com.xsn.explorer.errors.{PostgresForeignKeyViolationError, PreviousBlockMissingError, RepeatedBlockHeightError}
 import com.xsn.explorer.gcs.{GolombCodedSet, GolombEncoding}
+import com.xsn.explorer.models.TPoSContract
 import com.xsn.explorer.models.persisted.{Balance, Block, Transaction}
 import com.xsn.explorer.models.values.Address
 import com.xsn.explorer.util.Extensions.ListOptionExt
@@ -33,13 +34,14 @@ class LedgerPostgresDataHandler @Inject() (
    * to have a next block, we remove the link because that block is not stored yet.
    */
   override def push(
-      block: Block.HasTransactions): ApplicationResult[Unit] = {
+      block: Block.HasTransactions,
+      tposContracts: List[TPoSContract]): ApplicationResult[Unit] = {
 
     // the filter is computed outside the transaction to avoid unnecessary locking
     val filter = GolombEncoding.encode(block)
     val result = withTransaction { implicit conn =>
       val result = for {
-        _ <- upsertBlockCascade(block.asTip, filter)
+        _ <- upsertBlockCascade(block.asTip, filter, tposContracts)
       } yield ()
 
       result
@@ -72,7 +74,8 @@ class LedgerPostgresDataHandler @Inject() (
 
   private def upsertBlockCascade(
       block: Block.HasTransactions,
-      filter: Option[GolombCodedSet])(
+      filter: Option[GolombCodedSet],
+      tposContracts: List[TPoSContract])(
       implicit conn: Connection): Option[Unit] = {
 
     val result = for {
@@ -82,7 +85,7 @@ class LedgerPostgresDataHandler @Inject() (
       _ = filter.foreach { f => blockFilterPostgresDAO.insert(block.hash, f) }
 
       // batch insert
-      _ <- transactionPostgresDAO.insert(block.transactions)
+      _ <- transactionPostgresDAO.insert(block.transactions, tposContracts)
 
       // balances
       balanceList = balances(block.transactions)

server/app/com/xsn/explorer/data/anorm/dao/TransactionPostgresDAO.scala

@@ -17,6 +17,7 @@ import org.slf4j.LoggerFactory
 class TransactionPostgresDAO @Inject() (
     transactionInputDAO: TransactionInputPostgresDAO,
     transactionOutputDAO: TransactionOutputPostgresDAO,
+    tposContractDAO: TPoSContractDAO,
     addressTransactionDetailsDAO: AddressTransactionDetailsPostgresDAO,
     fieldOrderingSQLInterpreter: FieldOrderingSQLInterpreter) {
 
@@ -31,11 +32,13 @@ class TransactionPostgresDAO @Inject() (
       _ <- transactionOutputDAO.batchInsertOutputs(transaction.outputs)
       _ <- transactionInputDAO.batchInsertInputs(transaction.inputs.map(transaction.id -> _))
       _ <- transactionOutputDAO.batchSpend(transaction.id, transaction.inputs)
+      _ = closeContracts(List(transaction))
+      _ = transactionOutputDAO.batchSpend(transaction.id, transaction.inputs)
       _ <- addressTransactionDetailsDAO.batchInsertDetails(transaction)
     } yield Transaction.HasIO(partialTx, inputs = transaction.inputs, outputs = transaction.outputs)
   }
 
-  def insert(transactions: List[Transaction.HasIO])(implicit conn: Connection): Option[List[Transaction]] = {
+  def insert(transactions: List[Transaction.HasIO], tposContracts: List[TPoSContract])(implicit conn: Connection): Option[List[Transaction]] = {
     for {
       r <- batchInsert(transactions.map(_.transaction))
 
@@ -47,6 +50,8 @@ class TransactionPostgresDAO @Inject() (
     } yield {
       insertDetails(transactions)
       spend(transactions)
+      closeContracts(transactions)
+      tposContracts.foreach { contract => tposContractDAO.create(contract) }
       r
     }
   }
@@ -63,6 +68,17 @@ class TransactionPostgresDAO @Inject() (
     assert(spendResult.forall(_.isDefined), "Spending inputs batch failed")
   }
 
+  private def closeContracts(transactions: List[Transaction.HasIO])(implicit conn: Connection): Unit = {
+    for {
+      tx <- transactions
+      // a contract requires 1 XSN
+      input <- tx.inputs if input.value == 1
+    } {
+      val id = TPoSContract.Id(input.fromTxid, input.fromOutputIndex)
+      tposContractDAO.close(id, tx.id)
+    }
+  }
+
   private def batchInsert(transactions: List[Transaction])(implicit conn: Connection): Option[List[Transaction]] = {
     transactions match {
       case Nil => Some(transactions)
@@ -112,9 +128,16 @@ class TransactionPostgresDAO @Inject() (
     ).as(parseTransaction.*)
 
     val result = expectedTransactions.map { tx =>
+      val _ = (
+          tposContractDAO.deleteBy(tx.id),
+          addressTransactionDetailsDAO.deleteDetails(tx.id)
+      )
       val inputs = transactionInputDAO.deleteInputs(tx.id)
       val outputs = transactionOutputDAO.deleteOutputs(tx.id)
-      val _ = addressTransactionDetailsDAO.deleteDetails(tx.id)
+
+      inputs
+          .map { input => TPoSContract.Id(input.fromTxid, input.fromOutputIndex) }
+          .foreach(tposContractDAO.open(_))
 
       Transaction.HasIO(tx, inputs = inputs, outputs = outputs)
     }

server/app/com/xsn/explorer/data/async/LedgerFutureDataHandler.scala

@@ -3,6 +3,7 @@ package com.xsn.explorer.data.async
 import com.alexitc.playsonify.core.FutureApplicationResult
 import com.xsn.explorer.data.{LedgerBlockingDataHandler, LedgerDataHandler}
 import com.xsn.explorer.executors.DatabaseExecutionContext
+import com.xsn.explorer.models.TPoSContract
 import com.xsn.explorer.models.persisted.Block
 import javax.inject.Inject
 
@@ -13,8 +14,8 @@ class LedgerFutureDataHandler @Inject() (
     implicit ec: DatabaseExecutionContext)
     extends LedgerDataHandler[FutureApplicationResult] {
 
-  override def push(block: Block.HasTransactions): FutureApplicationResult[Unit] = Future {
-    blockingDataHandler.push(block)
+  override def push(block: Block.HasTransactions, tposContracts: List[TPoSContract]): FutureApplicationResult[Unit] = Future {
+    blockingDataHandler.push(block, tposContracts)
   }
 
   override def pop(): FutureApplicationResult[Block] = Future {

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

@@ -1,15 +1,16 @@
 package com.xsn.explorer.services
 
-import com.alexitc.playsonify.core.FutureApplicationResult
 import com.alexitc.playsonify.core.FutureOr.Implicits.{FutureOps, OptionOps}
+import com.alexitc.playsonify.core.{ApplicationResult, FutureApplicationResult}
 import com.xsn.explorer.data.async.{BlockFutureDataHandler, LedgerFutureDataHandler}
 import com.xsn.explorer.errors.BlockNotFoundError
+import com.xsn.explorer.models.TPoSContract
 import com.xsn.explorer.models.persisted.Block
 import com.xsn.explorer.models.transformers._
 import com.xsn.explorer.models.values.{Blockhash, Height}
 import com.xsn.explorer.util.Extensions.FutureOrExt
 import javax.inject.Inject
-import org.scalactic.Good
+import org.scalactic.{Bad, Good}
 import org.slf4j.LoggerFactory
 
 import scala.concurrent.{ExecutionContext, Future}
@@ -23,6 +24,8 @@ class LedgerSynchronizerService @Inject() (
     blockDataHandler: BlockFutureDataHandler)(
     implicit ec: ExecutionContext) {
 
+  import LedgerSynchronizerService._
+
   private val logger = LoggerFactory.getLogger(this.getClass)
 
   /**
@@ -34,14 +37,15 @@ class LedgerSynchronizerService @Inject() (
    */
   def synchronize(blockhash: Blockhash): FutureApplicationResult[Unit] = {
     val result = for {
-      block <- getRPCBlock(blockhash).toFutureOr
-      _ <- synchronize(block).toFutureOr
+      data <- getRPCBlock(blockhash).toFutureOr
+      _ <- synchronize(data).toFutureOr
     } yield ()
 
     result.toFuture
   }
 
-  private def synchronize(block: Block.HasTransactions): FutureApplicationResult[Unit] = {
+  private def synchronize(data: BlockData): FutureApplicationResult[Unit] = {
+    val block = data._1
     logger.info(s"Synchronize block ${block.height}, hash = ${block.hash}")
 
     val result = for {
@@ -52,8 +56,8 @@ class LedgerSynchronizerService @Inject() (
           .recoverFrom(BlockNotFoundError)(None)
 
       _ <- latestBlockMaybe
-          .map { latestBlock => onLatestBlock(latestBlock, block) }
-          .getOrElse { onEmptyLedger(block) }
+          .map { latestBlock => onLatestBlock(latestBlock, data) }
+          .getOrElse { onEmptyLedger(data) }
           .toFutureOr
     } yield ()
 
@@ -65,15 +69,16 @@ class LedgerSynchronizerService @Inject() (
    * 1.1. the given block is the genensis block, it is added.
    * 1.2. the given block is not the genesis block, sync everything until the given block.
    */
-  private def onEmptyLedger(block: Block.HasTransactions): FutureApplicationResult[Unit] = {
+  private def onEmptyLedger(data: BlockData): FutureApplicationResult[Unit] = {
+    val block = data._1
     if (block.height.int == 0) {
       logger.info(s"Synchronize genesis block on empty ledger, hash = ${block.hash}")
-      ledgerDataHandler.push(block)
+      ledgerDataHandler.push(block, data._2)
     } else {
       logger.info(s"Synchronize block ${block.height} on empty ledger, hash = ${block.hash}")
       val result = for {
         _ <- sync(0 until block.height.int).toFutureOr
-        _ <- synchronize(block).toFutureOr
+        _ <- synchronize(data).toFutureOr
       } yield ()
 
       result.toFuture
@@ -88,27 +93,28 @@ class LedgerSynchronizerService @Inject() (
    * 2.4. if H <= N, if the hash already exists, it is ignored.
    * 2.5. if H <= N, if the hash doesn't exists, remove blocks from N to H (included), then, add the new H.
    */
-  private def onLatestBlock(ledgerBlock: Block, newBlock: Block.HasTransactions): FutureApplicationResult[Unit] = {
+  private def onLatestBlock(ledgerBlock: Block, newData: BlockData): FutureApplicationResult[Unit] = {
+    val newBlock = newData._1
     if (ledgerBlock.height.int + 1 == newBlock.height.int &&
         newBlock.previousBlockhash.contains(ledgerBlock.hash)) {
 
       logger.info(s"Appending block ${newBlock.height}, hash = ${newBlock.hash}")
-      ledgerDataHandler.push(newBlock)
+      ledgerDataHandler.push(newBlock, newData._2)
     } else if (ledgerBlock.height.int + 1 == newBlock.height.int) {
       logger.info(s"Reorganization to push block ${newBlock.height}, hash = ${newBlock.hash}")
       val result = for {
         blockhash <- newBlock.previousBlockhash.toFutureOr(BlockNotFoundError)
         previousBlock <- getRPCBlock(blockhash).toFutureOr
         _ <- synchronize(previousBlock).toFutureOr
-        _ <- synchronize(newBlock).toFutureOr
+        _ <- synchronize(newData).toFutureOr
       } yield ()
 
       result.toFuture
     } else if (newBlock.height.int > ledgerBlock.height.int) {
       logger.info(s"Filling holes to push block ${newBlock.height}, hash = ${newBlock.hash}")
       val result = for {
         _ <- sync(ledgerBlock.height.int + 1 until newBlock.height.int).toFutureOr
-        _ <- synchronize(newBlock).toFutureOr
+        _ <- synchronize(newData).toFutureOr
       } yield ()
 
       result.toFuture
@@ -126,7 +132,7 @@ class LedgerSynchronizerService @Inject() (
             .getOrElse {
               val x = for {
                 _ <- trimTo(newBlock.height).toFutureOr
-                _ <- synchronize(newBlock).toFutureOr
+                _ <- synchronize(newData).toFutureOr
               } yield ()
               x.toFuture
             }
@@ -148,24 +154,59 @@ class LedgerSynchronizerService @Inject() (
       val result = for {
         _ <- previous.toFutureOr
         blockhash <- xsnService.getBlockhash(Height(height)).toFutureOr
-        block <- getRPCBlock(blockhash).toFutureOr
-        _ <- synchronize(block).toFutureOr
+        data <- getRPCBlock(blockhash).toFutureOr
+        _ <- synchronize(data).toFutureOr
       } yield ()
 
       result.toFuture
     }
   }
 
-  private def getRPCBlock(blockhash: Blockhash): FutureApplicationResult[Block.HasTransactions] = {
+  private def getRPCBlock(blockhash: Blockhash): FutureApplicationResult[BlockData] = {
     val result = for {
       rpcBlock <- xsnService.getBlock(blockhash).toFutureOr
       extractionMethod <- blockService.extractionMethod(rpcBlock).toFutureOr
-      transactions <- transactionRPCService.getTransactions(rpcBlock.transactions).toFutureOr
-    } yield toPersistedBlock(rpcBlock, extractionMethod).withTransactions(transactions)
+      data <- transactionRPCService.getTransactions(rpcBlock.transactions).toFutureOr
+      (transactions, contracts) = data
+      validContracts <- getValidContracts(contracts).toFutureOr
+    } yield {
+      val block = toPersistedBlock(rpcBlock, extractionMethod).withTransactions(transactions)
+      (block, validContracts)
+    }
 
     result.toFuture
   }
 
+  private def getValidContracts(contracts: List[TPoSContract]): FutureApplicationResult[List[TPoSContract]] = {
+    val listF = contracts
+        .map { contract =>
+          xsnService
+              .isTPoSContract(contract.txid)
+              .toFutureOr
+              .map { valid =>
+                if (valid) Some(contract)
+                else None
+              }
+              .toFuture
+        }
+
+    val futureList = Future.sequence(listF)
+    futureList.map { list =>
+      val x = list.flatMap {
+        case Good(a) => a.map(Good(_))
+        case Bad(e) => Some(Bad(e))
+      }
+
+      val initial: ApplicationResult[List[TPoSContract]] = Good(List.empty)
+      x.foldLeft(initial) { case (acc, cur) =>
+        cur match {
+          case Good(contract) => acc.map(contract :: _)
+          case Bad(e) => acc.badMap(prev => prev ++ e)
+        }
+      }
+    }
+  }
+
   /**
    * Trim the ledger until the given block height, if the height is 4,
    * the last stored block will be 3.
@@ -188,3 +229,8 @@ class LedgerSynchronizerService @Inject() (
     result.toFuture
   }
 }
+
+object LedgerSynchronizerService {
+
+  type BlockData = (Block.HasTransactions, List[TPoSContract])
+}

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

@@ -6,7 +6,7 @@ import com.xsn.explorer.errors.{InvalidRawTransactionError, TransactionFormatErr
 import com.xsn.explorer.models.persisted.Transaction
 import com.xsn.explorer.models.rpc.TransactionVIN
 import com.xsn.explorer.models.values._
-import com.xsn.explorer.models.{TransactionDetails, TransactionValue}
+import com.xsn.explorer.models.{TPoSContract, TransactionDetails, TransactionValue}
 import com.xsn.explorer.util.Extensions.FutureOrExt
 import javax.inject.Inject
 import org.scalactic.{Bad, Good, One, Or}
@@ -49,12 +49,12 @@ class TransactionRPCService @Inject() (
     result.toFuture
   }
 
-  def getTransaction(txid: TransactionId): FutureApplicationResult[Transaction.HasIO] = {
+  def getTransaction(txid: TransactionId): FutureApplicationResult[(Transaction.HasIO, Option[TPoSContract])] = {
     val result = for {
       tx <- xsnService.getTransaction(txid).toFutureOr
       transactionVIN <- getTransactionVIN(tx.vin).toFutureOr
       rpcTransaction = tx.copy(vin = transactionVIN)
-    } yield Transaction.fromRPC(rpcTransaction)._1
+    } yield Transaction.fromRPC(rpcTransaction)
 
     result.toFuture
   }
@@ -92,8 +92,8 @@ class TransactionRPCService @Inject() (
         }
   }
 
-  def getTransactions(ids: List[TransactionId]): FutureApplicationResult[List[Transaction.HasIO]] = {
-    def loadTransactionsSlowly(pending: List[TransactionId]): FutureOr[List[Transaction.HasIO]] = pending match {
+  def getTransactions(ids: List[TransactionId]): FutureApplicationResult[(List[Transaction.HasIO], List[TPoSContract])] = {
+    def loadTransactionsSlowly(pending: List[TransactionId]): FutureOr[List[(Transaction.HasIO, Option[TPoSContract])]] = pending match {
       case x :: xs =>
         for {
           tx <- getTransaction(x).toFutureOr
@@ -116,6 +116,13 @@ class TransactionRPCService @Inject() (
             logger.warn(s"Unable to load transactions due to server error, loading them sequentially, error = ${ex.getMessage}")
             loadTransactionsSlowly(ids).toFuture
         }
+        .toFutureOr
+        .map { result =>
+          val contracts = result.flatMap(_._2)
+          val txs = result.map(_._1)
+          (txs, contracts)
+        }
+        .toFuture
   }
 
   def sendRawTransaction(hexString: String): FutureApplicationResult[JsValue] = {