Fix some tips not deciaml type

extrinsic.go

@@ -139,10 +139,10 @@ func (e *ExtrinsicDecoder) Process() {
 			e.Nonce = int(e.ProcessAndUpdateData("Compact<U64>").(uint64))
 			if e.Metadata.Extrinsic != nil {
 				if utiles.SliceIndex("ChargeTransactionPayment", e.Metadata.Extrinsic.SignedIdentifier) != -1 {
-					result.Tip = e.ProcessAndUpdateData("Compact<Balance>").(decimal.Decimal)
+					result.Tip = utiles.DecimalFromInterface(e.ProcessAndUpdateData("Compact<Balance>"))
 				}
 			} else {
-				result.Tip = e.ProcessAndUpdateData("Compact<Balance>").(decimal.Decimal)
+				result.Tip = utiles.DecimalFromInterface(e.ProcessAndUpdateData("Compact<Balance>"))
 			}
 			// spec SignedExtensions
 			result.SignedExtensions = make(map[string]interface{})

utiles/tools.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"github.com/shopspring/decimal"
 	"math/big"
 	"reflect"
 	"strconv"
@@ -168,3 +169,24 @@ func GetEnumValue(e map[string]interface{}) (string, interface{}, error) {
 	}
 	return "", "", errors.New("empty enum")
 }
+
+func DecimalFromInterface(i interface{}) decimal.Decimal {
+	switch i := i.(type) {
+	case int:
+		return decimal.New(int64(i), 0)
+	case int64:
+		return decimal.New(i, 0)
+	case uint64:
+		return decimal.New(int64(i), 0)
+	case float64:
+		return decimal.NewFromFloat(i)
+	case string:
+		r, _ := decimal.NewFromString(i)
+		return r
+	case decimal.Decimal:
+		return i
+	case *big.Int:
+		return decimal.NewFromBigInt(i, 0)
+	}
+	return decimal.Zero
+}