rpc: implement getunclaimed

closes #712

pkg/rpc/response/result/unclaimed.go

@@ -0,0 +1,49 @@
+package result
+
+import (
+	"github.com/nspcc-dev/neo-go/pkg/core"
+	"github.com/nspcc-dev/neo-go/pkg/core/state"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+)
+
+// Unclaimed wrapper is used to represent getunclaimed return result.
+type Unclaimed struct {
+	Available   util.Fixed8 `json:"available"`
+	Unavailable util.Fixed8 `json:"unavailable"`
+	Unclaimed   util.Fixed8 `json:"unclaimed"`
+}
+
+// NewUnclaimed creates a new Unclaimed wrapper using given Blockchainer.
+func NewUnclaimed(a *state.Account, chain core.Blockchainer) (*Unclaimed, error) {
+	var (
+		available   util.Fixed8
+		unavailable util.Fixed8
+	)
+
+	for _, ucb := range a.Unclaimed {
+		gen, sys, err := chain.CalculateClaimable(ucb.Value, ucb.Start, ucb.End)
+		if err != nil {
+			return nil, err
+		}
+		available += gen + sys
+	}
+
+	blockHeight := chain.BlockHeight()
+	for _, usb := range a.Balances[core.GoverningTokenID()] {
+		_, txHeight, err := chain.GetTransaction(usb.Tx)
+		if err != nil {
+			return nil, err
+		}
+		gen, sys, err := chain.CalculateClaimable(usb.Value, txHeight, blockHeight)
+		if err != nil {
+			return nil, err
+		}
+		unavailable += gen + sys
+	}
+
+	return &Unclaimed{
+		Available:   available,
+		Unavailable: unavailable,
+		Unclaimed:   available + unavailable,
+	}, nil
+}