func (c *Client) checkAccountBalance(acc *account.Account, registration bool) error {
minimum := int64(account.NameMinimumBalance)
if registration {
// If we are doing the first registration of a name,
// we must have enough coins for two of the
// transactions.
minimum *= 2
}
if acc.Balance() < minimum {
// We must endow the account with funds.
// Grab the namecoin address of the account
hash, err := acc.PublicKeyHash()
if err != nil {
return err
}
addr := hash.String()
endowRequest, err := message.CreateMessage(&message.RequestFunds{
Address: &addr,
}, c.Origin, config.ServerAddress())
if err != nil {
return err
}
data, typ, h, err := adMessage.SendMessageAndReceiveWithTimestamp(
endowRequest,
c.Origin, config.ServerAddress())
if err != nil {
return err
} else if typ == wire.ErrorCode {
return adErrors.CreateErrorFromBytes(data, h)
} else if typ != message.TypeTransferFunds {
return errors.New("zooko/resolver: endowment received incorrect response type")
}
transferredFunds := new(message.TransferFunds)
if err := proto.Unmarshal(data, transferredFunds); err != nil {
return err
}
// Build the UTXO for the account
acc.Unspent = append(acc.Unspent, &account.UTXO{
TxID: *transferredFunds.Id,
Output: *transferredFunds.Index,
PkScript: transferredFunds.Script,
Amount: *transferredFunds.Amount,
})
// Go ahead and ensure that the account is now over the minimum
return c.checkAccountBalance(acc, registration)
}
// Otherwise, we are good to go.
return nil
}
// Renew will handle renewing (or updating) a name that is already
// owned by acc on the Zooko server.
func (c *Client) Renew(name string, reg *Registration, acc *account.Account) error {
jsonRegistration, err := json.Marshal(reg)
if err != nil {
return err
}
if err := c.checkAccountBalance(acc, false); err != nil {
return err
}
nameUpdate, err := acc.CreateNameUpdate(name, string(jsonRegistration))
if err != nil {
return err
}
nameUpdateBytes := &bytes.Buffer{}
if err := nameUpdate.Serialize(nameUpdateBytes); err != nil {
return err
}
updateMsg, err := message.CreateMessage(&message.RenewName{
Name: &name,
Value: jsonRegistration,
NameUpdate: nameUpdateBytes.Bytes(),
}, c.Origin, config.ServerAddress())
if err != nil {
return err
}
if err := c.getRegistrationResponse(updateMsg); err != nil {
return err
}
// Commit to the transaction since the server accepted it.
acc.Commit(nameUpdate)
return nil
}
// Register will handle the registration of a new name in the Zooko server.
func (c *Client) Register(name string, reg interface{}, acc *account.Account) error {
if _, found, _ := c.lookupString(name); found {
return errors.New("zooko: cannot register name that already exists")
}
jsonRegistration, err := json.Marshal(reg)
if err != nil {
return err
}
if err := c.checkAccountBalance(acc, true); err != nil {
return err
}
nameNew, rand, err := acc.CreateNameNew(name)
if err != nil {
return err
}
// Temporarily commit to the new transaction so that we can
// successfully create the name_firstupdate transaction.
oldUnspent := acc.Unspent
acc.Commit(nameNew)
undoCommit := func() {
acc.Unspent = oldUnspent
}
nameUpdate, err := acc.CreateNameFirstUpdate(rand, name, string(jsonRegistration))
if err != nil {
undoCommit()
return err
}
nameNewBytes := &bytes.Buffer{}
if err := nameNew.MsgTx.Serialize(nameNewBytes); err != nil {
undoCommit()
return err
}
nameFirstUpdateBytes := &bytes.Buffer{}
if err := nameUpdate.MsgTx.Serialize(nameFirstUpdateBytes); err != nil {
undoCommit()
return err
}
registrationMsg, err := message.CreateMessage(&message.RegisterName{
Name: &name,
Value: jsonRegistration,
NameNew: nameNewBytes.Bytes(),
NameFirstupdate: nameFirstUpdateBytes.Bytes(),
}, c.Origin, config.ServerAddress())
if err != nil {
undoCommit()
return err
}
if err := c.getRegistrationResponse(registrationMsg); err != nil {
undoCommit()
return err
}
// Add the name_firstupdate transaction to the list of pending
// transactions.
acc.Pending = append(acc.Pending, nameUpdate)
return nil
}