insight: DcrToInsightTxns can RPC for prevout addresses

For non-coinbase/stakebase inputs, the previous outpoint itself may be
in mempool, in which case it is necessary to retrieve the inputs' txns
and decode the pkScript.

Do not compute fee for coinbase, but do for votes.

api/insight/converter.go

@@ -9,6 +9,7 @@ import (
 	"github.com/decred/dcrd/dcrjson/v2"
 	"github.com/decred/dcrd/dcrutil"
 	apitypes "github.com/decred/dcrdata/api/types/v3"
+	"github.com/decred/dcrdata/txhelpers/v2"
 )
 
 // TxConverter converts dcrd-tx to insight tx
@@ -36,17 +37,25 @@ func (iapi *InsightApi) DcrToInsightTxns(txs []*dcrjson.TxRawResult, noAsm, noSc
 		}
 
 		// Vins
-		var vInSum float64
+		var vInSum dcrutil.Amount
 		for vinID, vin := range tx.Vin {
+			amt, _ := dcrutil.NewAmount(vin.AmountIn)
+			vInSum += amt
+
 			InsightVin := &apitypes.InsightVin{
 				Txid:     vin.Txid,
 				Vout:     newUint32Ptr(vin.Vout),
 				Sequence: newUint32Ptr(vin.Sequence),
 				N:        vinID,
 				Value:    vin.AmountIn,
+				ValueSat: int64(amt),
 				CoinBase: vin.Coinbase,
 			}
 
+			// Identify a vin corresponding to generated coins.
+			vinGenerated := vin.IsCoinBase() || vin.IsStakeBase()
+			txNew.IsCoinBase = txNew.IsCoinBase || vin.IsCoinBase() // exclude stakebase
+
 			// init ScriptPubKey
 			if !noScriptSig {
 				InsightVin.ScriptSig = new(apitypes.InsightScriptSig)
@@ -58,30 +67,32 @@ func (iapi *InsightApi) DcrToInsightTxns(txs []*dcrjson.TxRawResult, noAsm, noSc
 				}
 			}
 
-			// Note: this only gathers information from the database, which does
-			// not include mempool transactions.
-			_, addresses, value, err := iapi.BlockData.ChainDB.AddressIDsByOutpoint(vin.Txid, vin.Vout)
-			if err == nil {
-				if len(addresses) > 0 {
-					// Update Vin due to DCRD AMOUNTIN - START
-					// NOTE THIS IS ONLY USEFUL FOR INPUT AMOUNTS THAT ARE NOT ALSO FROM MEMPOOL
-					if tx.Confirmations == 0 {
-						InsightVin.Value = dcrutil.Amount(value).ToCoin()
-					}
-					// Update Vin due to DCRD AMOUNTIN - END
+			// First, attempt to get input addresses from our DB, which should
+			// work if the funding transaction is confirmed. Otherwise use RPC
+			// to get the funding transaction outpoint addresses.
+			if !vinGenerated {
+				_, addresses, _, err := iapi.BlockData.ChainDB.AddressIDsByOutpoint(vin.Txid, vin.Vout)
+				if err == nil && len(addresses) > 0 {
 					InsightVin.Addr = addresses[0]
+				} else {
+					// If the previous outpoint is from an unconfirmed transaction,
+					// fetch the prevout's addresses since dcrd does not include
+					// these details in the info for the spending transaction.
+					addrs, _, err := txhelpers.OutPointAddressesFromString(
+						vin.Txid, vin.Vout, vin.Tree, iapi.nodeClient, iapi.params)
+					if err != nil {
+						apiLog.Errorf("OutPointAddresses: %v", err)
+					} else if len(addrs) > 0 {
+						InsightVin.Addr = addrs[0]
+					}
 				}
 			}
-			dcramt, _ := dcrutil.NewAmount(InsightVin.Value)
-			InsightVin.ValueSat = int64(dcramt)
 
-			vInSum += InsightVin.Value
 			txNew.Vins = append(txNew.Vins, InsightVin)
-
 		}
 
 		// Vouts
-		var vOutSum float64
+		var vOutSum dcrutil.Amount
 		for _, v := range tx.Vout {
 			InsightVout := &apitypes.InsightVout{
 				Value: v.Value,
@@ -92,32 +103,26 @@ func (iapi *InsightApi) DcrToInsightTxns(txs []*dcrjson.TxRawResult, noAsm, noSc
 					Hex:       v.ScriptPubKey.Hex,
 				},
 			}
+
 			if !noAsm {
 				InsightVout.ScriptPubKey.Asm = v.ScriptPubKey.Asm
 			}
 
+			amt, _ := dcrutil.NewAmount(v.Value)
+			vOutSum += amt
+
 			txNew.Vouts = append(txNew.Vouts, InsightVout)
-			vOutSum += v.Value
 		}
 
-		dcramt, _ := dcrutil.NewAmount(vOutSum)
-		txNew.ValueOut = dcramt.ToCoin()
-
-		dcramt, _ = dcrutil.NewAmount(vInSum)
-		txNew.ValueIn = dcramt.ToCoin()
-
-		dcramt, _ = dcrutil.NewAmount(txNew.ValueIn - txNew.ValueOut)
-		txNew.Fees = dcramt.ToCoin()
-
-		// Return true if coinbase value is not empty, return 0 at some fields.
-		if txNew.Vins != nil && txNew.Vins[0].CoinBase != "" {
-			txNew.IsCoinBase = true
-			txNew.ValueIn = 0
-			txNew.Fees = 0
-			for _, v := range txNew.Vins {
-				v.Value = 0
-				v.ValueSat = 0
-			}
+		txNew.ValueIn = vInSum.ToCoin()
+		txNew.ValueOut = vOutSum.ToCoin()
+		// A coinbase transaction, but not necessarily a stakebase/vote, has no
+		// fee. Further, a coinbase transaction collects all of the mining fees
+		// for the transactions in the block, but there is no input that
+		// accounts for these collected fees. As such, never attempt to compute
+		// a transaction fee for the block's coinbase transaction.
+		if !txNew.IsCoinBase {
+			txNew.Fees = (vInSum - vOutSum).ToCoin()
 		}
 
 		if !noSpent {
@@ -128,10 +133,10 @@ func (iapi *InsightApi) DcrToInsightTxns(txs []*dcrjson.TxRawResult, noAsm, noSc
 			if err != nil {
 				return nil, err
 			}
-			for _, dbaddr := range addrFull {
-				txNew.Vouts[dbaddr.FundingTxVoutIndex].SpentIndex = dbaddr.SpendingTxVinIndex
-				txNew.Vouts[dbaddr.FundingTxVoutIndex].SpentTxID = dbaddr.SpendingTxHash
-				txNew.Vouts[dbaddr.FundingTxVoutIndex].SpentHeight = dbaddr.BlockHeight
+			for _, dbAddr := range addrFull {
+				txNew.Vouts[dbAddr.FundingTxVoutIndex].SpentIndex = dbAddr.SpendingTxVinIndex
+				txNew.Vouts[dbAddr.FundingTxVoutIndex].SpentTxID = dbAddr.SpendingTxHash
+				txNew.Vouts[dbAddr.FundingTxVoutIndex].SpentHeight = dbAddr.BlockHeight
 			}
 		}
 		newTxs = append(newTxs, txNew)

db/dcrpg/insightapi.go

@@ -117,14 +117,13 @@ func (pgb *ChainDB) InsightAddressTransactions(addr []string, recentBlockHeight
 }
 
 // AddressIDsByOutpoint fetches all address row IDs for a given outpoint
-// (txHash:voutIndex). TODO: Update the vin due to the issue with amountin
-// invalid for unconfirmed txns.
+// (txHash:voutIndex).
 func (pgb *ChainDB) AddressIDsByOutpoint(txHash string, voutIndex uint32) ([]uint64, []string, int64, error) {
 	ctx, cancel := context.WithTimeout(pgb.ctx, pgb.queryTimeout)
 	defer cancel()
 	ids, addrs, val, err := RetrieveAddressIDsByOutpoint(ctx, pgb.db, txHash, voutIndex)
 	return ids, addrs, val, pgb.replaceCancelError(err)
-} // Update Vin due to DCRD AMOUNTIN - END
+}
 
 // InsightSearchRPCAddressTransactions performs a searchrawtransactions for the
 // specified address, max number of transactions, and offset into the transaction

db/dcrpg/queries.go

@@ -2024,9 +2024,8 @@ func scanAddressQueryRows(rows *sql.Rows, queryType int) (addressRows []*dbtypes
 	return
 }
 
-// RetrieveAddressIDsByOutpoint fetches all address row IDs for a given outpoint
-// (hash:index).
-// Update Vin due to DCRD AMOUNTIN - START - DO NOT MERGE CHANGES IF DCRD FIXED
+// RetrieveAddressIDsByOutpoint gets all address row IDs, addresses, and values
+// for a given outpoint.
 func RetrieveAddressIDsByOutpoint(ctx context.Context, db *sql.DB, txHash string, voutIndex uint32) ([]uint64, []string, int64, error) {
 	var ids []uint64
 	var addresses []string
@@ -2049,7 +2048,7 @@ func RetrieveAddressIDsByOutpoint(ctx context.Context, db *sql.DB, txHash string
 		addresses = append(addresses, addr)
 	}
 	return ids, addresses, value, err
-} // Update Vin due to DCRD AMOUNTIN - END
+}
 
 // retrieveOldestTxBlockTime helps choose the most appropriate address page
 // graph grouping to load by default depending on when the first transaction to