rpc: use raw stack items in invoke* RPC

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

pkg/rpc/response/result/invoke.go

@@ -1,14 +1,76 @@
 package result
 
 import (
-	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
+	"encoding/json"
+
+	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 )
 
 // Invoke represents code invocation result and is used by several RPC calls
 // that invoke functions, scripts and generic bytecode.
 type Invoke struct {
-	State       string                    `json:"state"`
-	GasConsumed int64                     `json:"gasconsumed,string"`
-	Script      string                    `json:"script"`
-	Stack       []smartcontract.Parameter `json:"stack"`
+	State       string           `json:"state"`
+	GasConsumed int64            `json:"gasconsumed,string"`
+	Script      string           `json:"script"`
+	Stack       []stackitem.Item `json:"stack"`
+}
+
+type invokeAux struct {
+	State       string          `json:"state"`
+	GasConsumed int64           `json:"gasconsumed,string"`
+	Script      string          `json:"script"`
+	Stack       json.RawMessage `json:"stack"`
+}
+
+// MarshalJSON implements json.Marshaler.
+func (r Invoke) MarshalJSON() ([]byte, error) {
+	var st json.RawMessage
+	arr := make([]json.RawMessage, len(r.Stack))
+	for i := range arr {
+		data, err := stackitem.ToJSONWithTypes(r.Stack[i])
+		if err != nil {
+			st = []byte("error: recursive reference")
+			break
+		}
+		arr[i] = data
+	}
+
+	var err error
+	if st == nil {
+		st, err = json.Marshal(arr)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return json.Marshal(&invokeAux{
+		GasConsumed: r.GasConsumed,
+		Script:      r.Script,
+		State:       r.State,
+		Stack:       st,
+	})
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (r *Invoke) UnmarshalJSON(data []byte) error {
+	aux := new(invokeAux)
+	if err := json.Unmarshal(data, aux); err != nil {
+		return err
+	}
+	var arr []json.RawMessage
+	if err := json.Unmarshal(aux.Stack, &arr); err == nil {
+		st := make([]stackitem.Item, len(arr))
+		for i := range arr {
+			st[i], err = stackitem.FromJSONWithTypes(arr[i])
+			if err != nil {
+				break
+			}
+		}
+		if err == nil {
+			r.Stack = st
+		}
+	}
+	r.GasConsumed = aux.GasConsumed
+	r.Script = aux.Script
+	r.State = aux.State
+	return nil
 }