Multiple payout targets (issue #113)

migrations/v0.1.1.sql

@@ -0,0 +1,14 @@
+-- SQL Migration from v0.1.0-beta2 to v0.1.1
+
+ALTER TABLE payment DROP COLUMN pay_to;
+ALTER TABLE payment DROP COLUMN amount;
+ALTER TABLE payment ADD COLUMN total NUMERIC(18,8) NOT NULL;
+
+CREATE TABLE IF NOT EXISTS output (
+  payment_id INTEGER NOT NULL,
+  vout INTEGER NOT NULL,
+  pay_to TEXT NOT NULL,
+  amount NUMERIC(18,8) NOT NULL,
+  deduct_fee_percent NUMERIC(18,8) NOT NULL,
+  PRIMARY KEY (payment_id, vout)
+);

pkg/api.go

@@ -251,25 +251,31 @@ func (a API) UpdateAccountSettings(foreignID string, update map[string]interface
 	return pub, nil
 }
 
-func (a API) SendFundsToAddress(foreignID string, amount CoinAmount, payTo Address) (txid string, fee CoinAmount, err error) {
+func (a API) SendFundsToAddress(foreignID string, explicitFee CoinAmount, payTo []PayTo) (txid string, fee CoinAmount, err error) {
 	account, err := a.Store.GetAccount(foreignID)
 	if err != nil {
 		return
 	}
-	if amount.LessThan(TxnDustLimit) {
-		return "", ZeroCoins, NewErr(BadRequest, "amount is too small - transaction will be rejected: %s", amount.String())
+	total := decimal.Zero
+	for _, pay := range payTo {
+		total = total.Add(pay.Amount)
+		if pay.Amount.LessThan(TxnDustLimit) {
+			return "", ZeroCoins, NewErr(BadRequest, "amount is less than dust limit - transaction will be rejected: %s pay to %s", pay.Amount.String(), pay.PayTo)
+		}
 	}
 	builder, err := NewTxnBuilder(&account, a.Store, a.L1)
 	if err != nil {
 		return
 	}
-	err = builder.AddUTXOsUpToAmount(amount)
+	err = builder.AddUTXOsUpToAmount(total)
 	if err != nil {
 		return
 	}
-	err = builder.AddOutput(payTo, amount)
-	if err != nil {
-		return
+	for _, pay := range payTo {
+		err = builder.AddOutput(pay.PayTo, pay.Amount)
+		if err != nil {
+			return
+		}
 	}
 	err = builder.CalculateFee(ZeroCoins)
 	if err != nil {
@@ -283,32 +289,32 @@ func (a API) SendFundsToAddress(foreignID string, amount CoinAmount, payTo Addre
 	// Create the Payment record up-front.
 	// Save changes to the Account (NextInternalKey) and address pool.
 	// Reserve the UTXOs for the payment.
-	tx, err := a.Store.Begin()
+	dbtx, err := a.Store.Begin()
 	if err != nil {
 		return
 	}
-	err = account.UpdatePoolAddresses(tx, a.L1) // we have used an address.
+	err = account.UpdatePoolAddresses(dbtx, a.L1) // we have used an address.
 	if err != nil {
-		tx.Rollback()
+		dbtx.Rollback()
 		return
 	}
-	err = tx.UpdateAccount(account) // for NextInternalKey (change address)
+	err = dbtx.UpdateAccount(account) // for NextInternalKey (change address)
 	if err != nil {
-		tx.Rollback()
+		dbtx.Rollback()
 		return
 	}
 	// Create the `payment` row with no txid or paid_height.
-	payment, err := tx.CreatePayment(account.Address, amount, payTo)
+	payment, err := dbtx.CreatePayment(account.Address, total, payTo)
 	if err != nil {
-		tx.Rollback()
+		dbtx.Rollback()
 		return
 	}
 	// err = tx.ReserveUTXOsForPayment(payId, builder.GetUTXOs()) // TODO
 	// if err != nil {
 	//  tx.Rollback()
 	// 	return
 	// }
-	err = tx.Commit()
+	err = dbtx.Commit()
 	if err != nil {
 		return
 	}
@@ -321,16 +327,16 @@ func (a API) SendFundsToAddress(foreignID string, amount CoinAmount, payTo Addre
 
 	// Update the Payment with the txid,
 	// which changes it to "accepted" status (accepted by the network)
-	tx, err = a.Store.Begin()
+	dbtx, err = a.Store.Begin()
 	if err != nil {
 		return
 	}
-	err = tx.UpdatePaymentWithTxID(payment.ID, txid)
+	err = dbtx.UpdatePaymentWithTxID(payment.ID, txid)
 	if err != nil {
-		tx.Rollback()
+		dbtx.Rollback()
 		return
 	}
-	err = tx.Commit()
+	err = dbtx.Commit()
 	if err != nil {
 		return
 	}
@@ -340,7 +346,7 @@ func (a API) SendFundsToAddress(foreignID string, amount CoinAmount, payTo Addre
 		ForeignID: account.ForeignID,
 		AccountID: account.Address,
 		PayTo:     payTo,
-		Amount:    amount,
+		Total:     total,
 		TxID:      txid,
 	}
 	a.bus.Send(PAYMENT_SENT, msg)
@@ -360,7 +366,7 @@ func (a API) PayInvoiceFromAccount(invoiceID Address, foreignID string) (txid st
 	if invoiceAmount.LessThan(TxnDustLimit) {
 		return "", ZeroCoins, fmt.Errorf("invoice amount is too small - transaction will be rejected: %s", invoiceAmount.String())
 	}
-	payTo := invoice.ID // pay-to Address is the ID
+	payToAddress := invoice.ID // pay-to Address is the ID
 
 	// Make a Txn to pay `invoiceAmount` from `account` to `payTo`
 	builder, err := NewTxnBuilder(&account, a.Store, a.L1)
@@ -371,7 +377,7 @@ func (a API) PayInvoiceFromAccount(invoiceID Address, foreignID string) (txid st
 	if err != nil {
 		return
 	}
-	err = builder.AddOutput(payTo, invoiceAmount)
+	err = builder.AddOutput(payToAddress, invoiceAmount)
 	if err != nil {
 		return
 	}
@@ -384,11 +390,6 @@ func (a API) PayInvoiceFromAccount(invoiceID Address, foreignID string) (txid st
 		return
 	}
 
-	// TODO: submit the transaction to Core.
-	// TODO: store back the account (to save NextInternalKey; also call UpdatePoolAddresses)
-	// TODO: somehow reserve the UTXOs in the interim (prevent accidental double-spend)
-	//       until ChainTracker sees the Txn in a Block and calls MarkUTXOSpent.
-
 	// Create the Payment record up-front.
 	// Save changes to the Account (NextInternalKey) and address pool.
 	// Reserve the UTXOs for the payment.
@@ -407,6 +408,7 @@ func (a API) PayInvoiceFromAccount(invoiceID Address, foreignID string) (txid st
 		return
 	}
 	// Create the `payment` row with no txid or paid_height.
+	payTo := []PayTo{{Amount: invoiceAmount, PayTo: payToAddress}}
 	payment, err := tx.CreatePayment(account.Address, invoiceAmount, payTo)
 	if err != nil {
 		tx.Rollback()
@@ -449,7 +451,7 @@ func (a API) PayInvoiceFromAccount(invoiceID Address, foreignID string) (txid st
 		ForeignID: account.ForeignID,
 		AccountID: account.Address,
 		PayTo:     payTo,
-		Amount:    invoiceAmount,
+		Total:     invoiceAmount,
 		TxID:      txid,
 	}
 	a.bus.Send(PAYMENT_SENT, msg)

pkg/events.go

@@ -83,8 +83,8 @@ type PaymentEvent struct {
 	PaymentID int64      `json:"payment_id"`
 	AccountID Address    `json:"account_id"`
 	ForeignID string     `json:"foreign_id"`
-	PayTo     Address    `json:"pay_to"`
-	Amount    CoinAmount `json:"amount"`
+	PayTo     []PayTo    `json:"pay_to"`
+	Total     CoinAmount `json:"total"`
 	TxID      string     `json:"txid"`
 }
 

pkg/payment.go

@@ -1,12 +1,16 @@
 package giga
 
-import "time"
+import (
+	"time"
+
+	"github.com/shopspring/decimal"
+)
 
 type Payment struct {
 	ID               int64      // incrementing payment number, per account
 	AccountAddress   Address    // owner account (source of funds)
-	PayTo            Address    // a dogecoin address
-	Amount           CoinAmount // how much was paid
+	PayTo            []PayTo    // dogecoin addresses and amounts
+	Total            CoinAmount // total paid (excluding fees)
 	Created          time.Time  // when the payment was created
 	PaidTxID         string     // TXID of the Transaction that made the payment
 	PaidHeight       int64      // Block Height of the Transaction that made the payment
@@ -15,3 +19,11 @@ type Payment struct {
 	ConfirmedEvent   time.Time  // Time when the confirmed event was sent
 	UnconfirmedEvent time.Time  // Time when the unconfirmed event was sent
 }
+
+// Pay an amount to an address
+// optional DeductFeePercent deducts a percentage of required fees from each PayTo (should sum to 100)
+type PayTo struct {
+	Amount           CoinAmount      `json:"amount"`
+	PayTo            Address         `json:"to"`
+	DeductFeePercent decimal.Decimal `json:"deduct_fee_percent"`
+}

pkg/services/balancekeeper.go

@@ -328,7 +328,7 @@ func (b BalanceKeeper) sendPaymentEvents(tx giga.StoreTransaction, acc *giga.Acc
 					ForeignID: acc.ForeignID,
 					AccountID: acc.Address,
 					PayTo:     pay.PayTo,
-					Amount:    pay.Amount,
+					Total:     pay.Total,
 					TxID:      pay.PaidTxID,
 				}
 				event := giga.PAYMENT_ON_CHAIN
@@ -351,7 +351,7 @@ func (b BalanceKeeper) sendPaymentEvents(tx giga.StoreTransaction, acc *giga.Acc
 					ForeignID: acc.ForeignID,
 					AccountID: acc.Address,
 					PayTo:     pay.PayTo,
-					Amount:    pay.Amount,
+					Total:     pay.Total,
 					TxID:      pay.PaidTxID,
 				}
 				event := giga.PAYMENT_CONFIRMED

pkg/store.go

@@ -97,7 +97,7 @@ type StoreTransaction interface {
 
 	// Store a 'payment' which represents a pay-out to another address from a gigawallet
 	// managed account.
-	CreatePayment(account Address, amount CoinAmount, payTo Address) (Payment, error)
+	CreatePayment(account Address, amount CoinAmount, payTo []PayTo) (Payment, error)
 
 	// GetPayment returns the Payment for the given ID
 	GetPayment(account Address, id int64) (Payment, error)

pkg/store/sqlite.go

@@ -62,9 +62,8 @@ CREATE INDEX IF NOT EXISTS invoice_account_i ON invoice (account_address);
 CREATE TABLE IF NOT EXISTS payment (
 	id INTEGER PRIMARY KEY AUTOINCREMENT,
 	account_address TEXT NOT NULL,
-	pay_to TEXT NOT NULL,
-	amount NUMERIC(18,8) NOT NULL,
 	created DATETIME NOT NULL,
+	total NUMERIC(18,8) NOT NULL,
 	paid_txid TEXT,
 	paid_height INTEGER,
 	confirmed_height INTEGER,
@@ -77,6 +76,15 @@ CREATE INDEX IF NOT EXISTS payment_account_i ON payment (account_address);
 CREATE INDEX IF NOT EXISTS payment_txid_i ON payment (paid_txid);
 CREATE INDEX IF NOT EXISTS payment_paid_height_i ON payment (paid_height);
 
+CREATE TABLE IF NOT EXISTS output (
+	payment_id INTEGER NOT NULL,
+	vout INTEGER NOT NULL,
+	pay_to TEXT NOT NULL,
+	amount NUMERIC(18,8) NOT NULL,
+	deduct_fee_percent NUMERIC(18,8) NOT NULL,
+	PRIMARY KEY (payment_id, vout)
+);
+
 CREATE TABLE IF NOT EXISTS utxo (
 	txn_id TEXT NOT NULL,
 	vout INTEGER NOT NULL,
@@ -412,7 +420,7 @@ func (s SQLiteStore) listInvoicesCommon(tx Queryable, account giga.Address, curs
 }
 
 // These must match the row.Scan in scanPayment below.
-const payment_select_cols = "id, account_address, pay_to, amount, created, paid_txid, paid_height, confirmed_height, on_chain_event, confirmed_event, unconfirmed_event"
+const payment_select_cols = "id, account_address, total, created, paid_txid, paid_height, confirmed_height, on_chain_event, confirmed_event, unconfirmed_event"
 
 func (s SQLiteStore) scanPayment(row Scannable, account giga.Address) (giga.Payment, error) {
 	var paid_txid sql.NullString
@@ -422,7 +430,7 @@ func (s SQLiteStore) scanPayment(row Scannable, account giga.Address) (giga.Paym
 	var confirmed_event sql.NullTime
 	var unconfirmed_event sql.NullTime
 	pay := giga.Payment{}
-	err := row.Scan(&pay.ID, &pay.AccountAddress, &pay.PayTo, &pay.Amount, &pay.Created, &paid_txid, &paid_height, &confirmed_height, &on_chain_event, &confirmed_event, &unconfirmed_event)
+	err := row.Scan(&pay.ID, &pay.AccountAddress, &pay.Total, &pay.Created, &paid_txid, &paid_height, &confirmed_height, &on_chain_event, &confirmed_event, &unconfirmed_event)
 	if err == sql.ErrNoRows {
 		return pay, giga.NewErr(giga.NotFound, "payment not found: %v", account)
 	}
@@ -452,8 +460,32 @@ func (s SQLiteStore) scanPayment(row Scannable, account giga.Address) (giga.Paym
 
 var get_payment_sql = fmt.Sprintf("SELECT %s FROM payment WHERE id = $1 AND account_address = $2", payment_select_cols)
 
+func (s SQLiteStore) getPaymentOutputs(tx Queryable, payment_id int64) (result []giga.PayTo, err error) {
+	rows, err := tx.Query("SELECT pay_to, amount, deduct_fee_percent FROM output WHERE payment_id=$1 ORDER BY vout", payment_id)
+	if err != nil {
+		return nil, s.dbErr(err, "getPaymentOutputs: querying PayTo")
+	}
+	defer rows.Close()
+	for rows.Next() {
+		pay := giga.PayTo{}
+		err := rows.Scan(&pay.PayTo, &pay.Amount, &pay.DeductFeePercent)
+		if err != nil {
+			return nil, s.dbErr(err, "getPaymentOutputs: scanning PayTo")
+		}
+		result = append(result, pay)
+	}
+	if err = rows.Err(); err != nil { // docs say this check is required!
+		return nil, s.dbErr(err, "getPaymentOutputs: querying PayTo")
+	}
+	return
+}
+
 func (s SQLiteStore) getPaymentCommon(tx Queryable, account giga.Address, id int64) (giga.Payment, error) {
-	return s.scanPayment(tx.QueryRow(get_payment_sql, id, account), account)
+	pay, err := s.scanPayment(tx.QueryRow(get_payment_sql, id, account), account)
+	if err == nil {
+		pay.PayTo, err = s.getPaymentOutputs(tx, pay.ID)
+	}
+	return pay, err
 }
 
 var list_payments_sql = fmt.Sprintf("SELECT %s FROM payment WHERE account_address = $1 AND id >= $2 ORDER BY id LIMIT $3", payment_select_cols)
@@ -465,12 +497,16 @@ func (s SQLiteStore) listPaymentsCommon(tx Queryable, account giga.Address, curs
 	}
 	defer rows.Close()
 	for rows.Next() {
-		p, err := s.scanPayment(rows, account)
+		pay, err := s.scanPayment(rows, account)
 		if err != nil {
 			return nil, 0, err // already s.dbErr
 		}
-		items = append(items, p)
-		next_cursor = p.ID + 1
+		pay.PayTo, err = s.getPaymentOutputs(tx, pay.ID)
+		if err != nil {
+			return nil, 0, err // already s.dbErr
+		}
+		items = append(items, pay)
+		next_cursor = pay.ID + 1
 	}
 	if err = rows.Err(); err != nil { // docs say this check is required!
 		return nil, 0, s.dbErr(err, "ListPayments: querying invoices")
@@ -596,21 +632,32 @@ func (t SQLiteStoreTransaction) StoreInvoice(inv giga.Invoice) error {
 	return nil
 }
 
-func (t SQLiteStoreTransaction) CreatePayment(accountAddr giga.Address, amount giga.CoinAmount, payTo giga.Address) (giga.Payment, error) {
+func (t SQLiteStoreTransaction) CreatePayment(accountAddr giga.Address, total giga.CoinAmount, payTo []giga.PayTo) (giga.Payment, error) {
+	stmt, err := t.tx.Prepare("INSERT INTO output (payment_id, vout, pay_to, amount, deduct_fee_percent) VALUES ($1,$2,$3,$4,$5)")
+	if err != nil {
+		return giga.Payment{}, t.store.dbErr(err, "CreatePayment: preparing insert")
+	}
+	defer stmt.Close()
 	now := time.Now()
 	row := t.tx.QueryRow(
 		"insert into payment(account_address, pay_to, amount, created) values($1,$2,$3,$4) returning id",
-		accountAddr, payTo, amount, now)
+		accountAddr, payTo, total, now)
 	var id int64
-	err := row.Scan(&id)
+	err = row.Scan(&id)
 	if err != nil {
 		return giga.Payment{}, t.store.dbErr(err, "createPayment: insert")
 	}
+	for vout, pt := range payTo {
+		_, err = stmt.Exec(id, vout, pt.PayTo, pt.Amount, pt.DeductFeePercent)
+		if err != nil {
+			return giga.Payment{}, t.store.dbErr(err, "CreatePayment: executing insert")
+		}
+	}
 	return giga.Payment{
 		ID:             id,
 		AccountAddress: accountAddr,
 		PayTo:          payTo,
-		Amount:         amount,
+		Total:          total,
 		Created:        now,
 	}, nil
 }