rpc: implement getunclaimed

closes #712

pkg/rpc/server/prometheus.go

@@ -178,6 +178,14 @@ var (
 		},
 	)
 
+	getunclaimedCalled = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Help:      "Number of calls to getunclaimed rpc endpoint",
+			Name:      "getunclaimed_called",
+			Namespace: "neogo",
+		},
+	)
+
 	getunspentsCalled = prometheus.NewCounter(
 		prometheus.CounterOpts{
 			Help:      "Number of calls to getunspents rpc endpoint",
@@ -229,6 +237,7 @@ func init() {
 		validateaddressCalled,
 		getassetstateCalled,
 		getaccountstateCalled,
+		getunclaimedCalled,
 		getunspentsCalled,
 		gettransactionheightCalled,
 		gettxoutCalled,

pkg/rpc/server/server.go

@@ -298,6 +298,10 @@ Methods:
 		gettxoutCalled.Inc()
 		results, resultsErr = s.getTxOut(reqParams)
 
+	case "getunclaimed":
+		getunclaimedCalled.Inc()
+		results, resultsErr = s.getUnclaimed(reqParams)
+
 	case "getunspents":
 		getunspentsCalled.Inc()
 		results, resultsErr = s.getAccountState(reqParams, true)
@@ -768,6 +772,25 @@ func (s *Server) getBlockHeader(reqParams request.Params) (interface{}, error) {
 	return hex.EncodeToString(buf.Bytes()), nil
 }
 
+// getUnclaimed returns unclaimed GAS amount of the specified address.
+func (s *Server) getUnclaimed(ps request.Params) (interface{}, error) {
+	p, ok := ps.ValueWithType(0, request.StringT)
+	if !ok {
+		return nil, response.ErrInvalidParams
+	}
+	u, err := p.GetUint160FromAddress()
+	if err != nil {
+		return nil, response.ErrInvalidParams
+	}
+
+	acc := s.chain.GetAccountState(u)
+	if acc == nil {
+		return nil, response.NewInternalServerError("unknown account", nil)
+	}
+
+	return result.NewUnclaimed(acc, s.chain)
+}
+
 // getValidators returns the current NEO consensus nodes information and voting status.
 func (s *Server) getValidators() (interface{}, error) {
 	var validators keys.PublicKeys

pkg/rpc/server/server_test.go

@@ -601,6 +601,32 @@ var rpcTestCases = map[string][]rpcTestCase{
 			fail:   true,
 		},
 	},
+	"getunclaimed": {
+		{
+			name:   "no params",
+			params: "[]",
+			fail:   true,
+		},
+		{
+			name:   "invalid address",
+			params: `["invalid"]`,
+			fail:   true,
+		},
+		{
+			name:   "positive",
+			params: `["AZ81H31DMWzbSnFDLFkzh9vHwaDLayV7fU"]`,
+			result: func(*executor) interface{} {
+				return &result.Unclaimed{}
+			},
+			check: func(t *testing.T, e *executor, uncl interface{}) {
+				res, ok := uncl.(*result.Unclaimed)
+				require.True(t, ok)
+				assert.Equal(t, res.Available, util.Fixed8FromInt64(8))
+				assert.True(t, res.Unavailable > 0)
+				assert.Equal(t, res.Available + res.Unavailable, res.Unclaimed)
+			},
+		},
+	},
 	"getunspents": {
 		{
 			name:   "positive",