wallet: use a script instead a hash

NEO wallets (e.g. used in privnet setup) use hex-encoded
script inside the wallet, not a script hash.

pkg/wallet/account.go

@@ -1,10 +1,11 @@
 package wallet
 
 import (
+	"encoding/hex"
+	"encoding/json"
 	"errors"
 
 	"github.com/CityOfZion/neo-go/pkg/crypto/keys"
-	"github.com/CityOfZion/neo-go/pkg/util"
 )
 
 // Account represents a NEO account. It holds the private and public key
@@ -43,8 +44,8 @@ type Account struct {
 // Contract represents a subset of the smartcontract to embed in the
 // Account so it's NEP-6 compliant.
 type Contract struct {
-	// Script hash of the contract deployed on the blockchain.
-	Script util.Uint160 `json:"script"`
+	// Script of the contract deployed on the blockchain.
+	Script []byte `json:"script"`
 
 	// A list of parameters used deploying this contract.
 	Parameters []interface{} `json:"parameters"`
@@ -53,6 +54,49 @@ type Contract struct {
 	Deployed bool `json:"deployed"`
 }
 
+// contract is an intermediate struct used for json unmarshalling.
+type contract struct {
+	// Script is a hex-encoded script of the contract.
+	Script string `json:"script"`
+
+	// A list of parameters used deploying this contract.
+	Parameters []interface{} `json:"parameters"`
+
+	// Indicates whether the contract has been deployed to the blockchain.
+	Deployed bool `json:"deployed"`
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (c Contract) MarshalJSON() ([]byte, error) {
+	var cc contract
+
+	cc.Script = hex.EncodeToString(c.Script)
+	cc.Parameters = c.Parameters
+	cc.Deployed = c.Deployed
+
+	return json.Marshal(cc)
+}
+
+// UnmarshalJSON implements json.Unmarshaler interface.
+func (c *Contract) UnmarshalJSON(data []byte) error {
+	var cc contract
+
+	if err := json.Unmarshal(data, &cc); err != nil {
+		return err
+	}
+
+	script, err := hex.DecodeString(cc.Script)
+	if err != nil {
+		return err
+	}
+
+	c.Script = script
+	c.Parameters = cc.Parameters
+	c.Deployed = cc.Deployed
+
+	return nil
+}
+
 // NewAccount creates a new Account with a random generated PrivateKey.
 func NewAccount() (*Account, error) {
 	priv, err := keys.NewPrivateKey()

pkg/wallet/account_test.go

@@ -2,6 +2,7 @@ package wallet
 
 import (
 	"encoding/hex"
+	"encoding/json"
 	"testing"
 
 	"github.com/CityOfZion/neo-go/pkg/internal/keytestcases"
@@ -47,6 +48,24 @@ func TestNewFromWif(t *testing.T) {
 	}
 }
 
+func TestContract_MarshalJSON(t *testing.T) {
+	var c Contract
+
+	data := []byte(`{"script":"0102","parameters":[1],"deployed":false}`)
+	require.NoError(t, json.Unmarshal(data, &c))
+	require.Equal(t, []byte{1, 2}, c.Script)
+
+	result, err := json.Marshal(c)
+	require.NoError(t, err)
+	require.JSONEq(t, string(data), string(result))
+
+	data = []byte(`1`)
+	require.Error(t, json.Unmarshal(data, &c))
+
+	data = []byte(`{"script":"ERROR","parameters":[1],"deployed":false}`)
+	require.Error(t, json.Unmarshal(data, &c))
+}
+
 func compareFields(t *testing.T, tk keytestcases.Ktype, acc *Account) {
 	if want, have := tk.Address, acc.Address; want != have {
 		t.Fatalf("expected %s got %s", want, have)