dcrjson: add fundrawtransaction command

dcrjson/walletsvrcmds.go

@@ -240,6 +240,32 @@ func NewEstimatePriorityCmd(numBlocks int64) *EstimatePriorityCmd {
 	}
 }
 
+// FundRawTransactionOptions represents the optional inputs to fund
+// a raw transaction.
+type FundRawTransactionOptions struct {
+	ChangeAddress *string  `json:"changeaddress"`
+	FeeRate       *float64 `json:"feerate"`
+	ConfTarget    *int32   `json:"conf_target"`
+}
+
+// FundRawTransactionCmd is a type handling custom marshaling and
+// unmarshaling of fundrawtransaction JSON wallet extension commands.
+type FundRawTransactionCmd struct {
+	HexString   string
+	FundAccount string
+	Options     *FundRawTransactionOptions
+}
+
+// NewFundRawTransactionCmd returns a new instance which can be used to issue a
+// fundrawtransaction JSON-RPC command.
+func NewFundRawTransactionCmd(hexString string, fundAccount string, options *FundRawTransactionOptions) *FundRawTransactionCmd {
+	return &FundRawTransactionCmd{
+		HexString:   hexString,
+		FundAccount: fundAccount,
+		Options:     options,
+	}
+}
+
 // GenerateVoteCmd is a type handling custom marshaling and
 // unmarshaling of generatevote JSON wallet extension commands.
 type GenerateVoteCmd struct {
@@ -1270,6 +1296,7 @@ func init() {
 	MustRegisterCmd("dropvotingaccount", (*DropVotingAccountCmd)(nil), flags)
 	MustRegisterCmd("dumpprivkey", (*DumpPrivKeyCmd)(nil), flags)
 	MustRegisterCmd("estimatepriority", (*EstimatePriorityCmd)(nil), flags)
+	MustRegisterCmd("fundrawtransaction", (*FundRawTransactionCmd)(nil), flags)
 	MustRegisterCmd("generatevote", (*GenerateVoteCmd)(nil), flags)
 	MustRegisterCmd("getaccount", (*GetAccountCmd)(nil), flags)
 	MustRegisterCmd("getaccountaddress", (*GetAccountAddressCmd)(nil), flags)

dcrjson/walletsvrresults.go

@@ -5,6 +5,12 @@
 
 package dcrjson
 
+// FundRawTransactionResult models the data from the fundrawtransaction command.
+type FundRawTransactionResult struct {
+	Hex string  `json:"hex"`
+	Fee float64 `json:"fee"`
+}
+
 // GenerateVoteResult models the data from the generatevote command.
 type GenerateVoteResult struct {
 	Hex string `json:"hex"`

rpcclient/wallet.go

@@ -2738,6 +2738,44 @@ func (c *Client) AddTicket(ticket *dcrutil.Tx) error {
 	return c.AddTicketAsync(hex.EncodeToString(ticketB)).Receive()
 }
 
+// FutureFundRawTransactionResult is a future promise to deliver the result of a
+// FundRawTransactionAsync RPC invocation (or an applicable error).
+type FutureFundRawTransactionResult chan *response
+
+// Receive waits for the response promised by the future and returns the unsigned
+// transaction with the passed amount and the given address.
+func (r FutureFundRawTransactionResult) Receive() (*dcrjson.FundRawTransactionResult, error) {
+	res, err := receiveFuture(r)
+	if err != nil {
+		return nil, err
+	}
+
+	// Unmarshal result as a string.
+	var infoRes dcrjson.FundRawTransactionResult
+	err = json.Unmarshal(res, &infoRes)
+	if err != nil {
+		return nil, err
+	}
+
+	return &infoRes, nil
+}
+
+// FundRawTransactionAsync returns an instance of a type that can be used to get the
+// result of the RPC at some future time by invoking the Receive function on the
+// returned instance.
+//
+// See FundRawTransaction for the blocking version and more details.
+func (c *Client) FundRawTransactionAsync(rawhex string, fundAccount string, options dcrjson.FundRawTransactionOptions) FutureFundRawTransactionResult {
+	cmd := dcrjson.NewFundRawTransactionCmd(rawhex, fundAccount, &options)
+	return c.sendCmd(cmd)
+}
+
+// FundRawTransaction Add inputs to a transaction until it has enough
+// in value to meet its out value.
+func (c *Client) FundRawTransaction(rawhex string, fundAccount string, options dcrjson.FundRawTransactionOptions) (*dcrjson.FundRawTransactionResult, error) {
+	return c.FundRawTransactionAsync(rawhex, fundAccount, options).Receive()
+}
+
 // FutureGenerateVoteResult is a future promise to deliver the result of a
 // GenerateVoteAsync RPC invocation (or an applicable error).
 type FutureGenerateVoteResult chan *response

rpcserver.go

@@ -253,6 +253,7 @@ var rpcAskWallet = map[string]struct{}{
 	"createencryptedwallet":   {},
 	"createmultisig":          {},
 	"dumpprivkey":             {},
+	"fundrawtransaction":      {},
 	"getaccount":              {},
 	"getaccountaddress":       {},
 	"getaddressesbyaccount":   {},