func (u *Unmarshaler) unmarshalValue(target reflect.Value, inputValue json.RawMessage, prop *proto.Properties) error {
	targetType := target.Type()
	if targetType.Kind() == reflect.Ptr {
		target.Set(reflect.New(targetType.Elem()))
		return u.unmarshalValue(target.Elem(), inputValue, prop)
	}
	type wkt interface {
		XXX_WellKnownType() string
	}
	if wkt, ok := target.Addr().Interface().(wkt); ok {
		switch wkt.XXX_WellKnownType() {
		case "DoubleValue", "FloatValue", "Int64Value", "UInt64Value",
			"Int32Value", "UInt32Value", "BoolValue", "StringValue", "BytesValue":
			return u.unmarshalValue(target.Field(0), inputValue, prop)
		case "Any":
			return fmt.Errorf("unmarshaling Any not supported yet")
		case "Duration":
			ivStr := string(inputValue)
			if ivStr == "null" {
				target.Field(0).SetInt(0)
				target.Field(1).SetInt(0)
				return nil
			}
			unq, err := strconv.Unquote(ivStr)
			if err != nil {
				return err
			}
			d, err := time.ParseDuration(unq)
			if err != nil {
				return fmt.Errorf("bad Duration: %v", err)
			}
			ns := d.Nanoseconds()
			s := ns / 1e9
			ns %= 1e9
			target.Field(0).SetInt(s)
			target.Field(1).SetInt(ns)
			return nil
		case "Timestamp":
			ivStr := string(inputValue)
			if ivStr == "null" {
				target.Field(0).SetInt(0)
				target.Field(1).SetInt(0)
				return nil
			}
			unq, err := strconv.Unquote(ivStr)
			if err != nil {
				return err
			}
			t, err := time.Parse(time.RFC3339Nano, unq)
			if err != nil {
				return fmt.Errorf("bad Timestamp: %v", err)
			}
			target.Field(0).SetInt(int64(t.Unix()))
			target.Field(1).SetInt(int64(t.Nanosecond()))
			return nil
		}
	}
	if inputValue[0] == '"' && prop != nil && prop.Enum != "" {
		vmap := proto.EnumValueMap(prop.Enum)
		s := inputValue[1 : len(inputValue)-1]
		n, ok := vmap[string(s)]
		if !ok {
			return fmt.Errorf("unknown value %q for enum %s", s, prop.Enum)
		}
		if target.Kind() == reflect.Ptr {  
			target.Set(reflect.New(targetType.Elem()))
			target = target.Elem()
		}
		target.SetInt(int64(n))
		return nil
	}
	if targetType.Kind() == reflect.Struct {
		var jsonFields map[string]json.RawMessage
		if err := json.Unmarshal(inputValue, &jsonFields); err != nil {
			return err
		}
		consumeField := func(prop *proto.Properties) (json.RawMessage, bool) {
			fieldNames := acceptedJSONFieldNames(prop)
			vOrig, okOrig := jsonFields[fieldNames.orig]
			vCamel, okCamel := jsonFields[fieldNames.camel]
			if !okOrig && !okCamel {
				return nil, false
			}
			var raw json.RawMessage
			if okOrig {
				raw = vOrig
				delete(jsonFields, fieldNames.orig)
			}
			if okCamel {
				raw = vCamel
				delete(jsonFields, fieldNames.camel)
			}
			return raw, true
		}
		sprops := proto.GetProperties(targetType)
		for i := 0; i < target.NumField(); i++ {
			ft := target.Type().Field(i)
			if strings.HasPrefix(ft.Name, "XXX_") {
				continue
			}
			valueForField, ok := consumeField(sprops.Prop[i])
			if !ok {
				continue
			}
			if err := u.unmarshalValue(target.Field(i), valueForField, sprops.Prop[i]); err != nil {
				return err
			}
		}
		if len(jsonFields) > 0 {
			for _, oop := range sprops.OneofTypes {
				raw, ok := consumeField(oop.Prop)
				if !ok {
					continue
				}
				nv := reflect.New(oop.Type.Elem())
				target.Field(oop.Field).Set(nv)
				if err := u.unmarshalValue(nv.Elem().Field(0), raw, oop.Prop); err != nil {
					return err
				}
			}
		}
		if !u.AllowUnknownFields && len(jsonFields) > 0 {
			var f string
			for fname := range jsonFields {
				f = fname
				break
			}
			return fmt.Errorf("unknown field %q in %v", f, targetType)
		}
		return nil
	}
	if targetType.Kind() == reflect.Slice && targetType.Elem().Kind() != reflect.Uint8 {
		var slc []json.RawMessage
		if err := json.Unmarshal(inputValue, &slc); err != nil {
			return err
		}
		len := len(slc)
		target.Set(reflect.MakeSlice(targetType, len, len))
		for i := 0; i < len; i++ {
			if err := u.unmarshalValue(target.Index(i), slc[i], prop); err != nil {
				return err
			}
		}
		return nil
	}
	if targetType.Kind() == reflect.Map {
		var mp map[string]json.RawMessage
		if err := json.Unmarshal(inputValue, &mp); err != nil {
			return err
		}
		target.Set(reflect.MakeMap(targetType))
		var keyprop, valprop *proto.Properties
		if prop != nil {
		}
		for ks, raw := range mp {
			var k reflect.Value
			if targetType.Key().Kind() == reflect.String {
				k = reflect.ValueOf(ks)
			} else {
				k = reflect.New(targetType.Key()).Elem()
				if err := u.unmarshalValue(k, json.RawMessage(ks), keyprop); err != nil {
					return err
				}
			}
			v := reflect.New(targetType.Elem()).Elem()
			if err := u.unmarshalValue(v, raw, valprop); err != nil {
				return err
			}
			target.SetMapIndex(k, v)
		}
		return nil
	}
	isNum := targetType.Kind() == reflect.Int64 || targetType.Kind() == reflect.Uint64
	if isNum && strings.HasPrefix(string(inputValue), `"`) {
		inputValue = inputValue[1 : len(inputValue)-1]
	}
	return json.Unmarshal(inputValue, target.Addr().Interface())
}
unmarshalValue converts/copies a value into the target.
prop may be nil.
package jsonpb
import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"reflect"
	"sort"
	"strconv"
	"strings"
	"time"
	"github.com/golang/protobuf/proto"
)
type Marshaler struct {
	EnumsAsInts bool
	EmitDefaults bool
	Indent string
	OrigName bool
}
func (m *Marshaler) Marshal(out io.Writer, pb proto.Message) error {
	writer := &errWriter{writer: out}
	return m.marshalObject(writer, pb, "", "")
}
func (m *Marshaler) MarshalToString(pb proto.Message) (string, error) {
	var buf bytes.Buffer
	if err := m.Marshal(&buf, pb); err != nil {
		return "", err
	}
	return buf.String(), nil
}
type int32Slice []int32
func (s int32Slice) Len() int           { return len(s) }
func (s int32Slice) Less(i, j int) bool { return s[i] < s[j] }
func (s int32Slice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
type wkt interface {
	XXX_WellKnownType() string
}
func (m *Marshaler) marshalObject(out *errWriter, v proto.Message, indent, typeURL string) error {
	s := reflect.ValueOf(v).Elem()
	if wkt, ok := v.(wkt); ok {
		switch wkt.XXX_WellKnownType() {
		case "DoubleValue", "FloatValue", "Int64Value", "UInt64Value",
			"Int32Value", "UInt32Value", "BoolValue", "StringValue", "BytesValue":
			sprop := proto.GetProperties(s.Type())
			return m.marshalValue(out, sprop.Prop[0], s.Field(0), indent)
		case "Any":
			return m.marshalAny(out, v, indent)
		case "Duration":
			s, ns := s.Field(0).Int(), s.Field(1).Int()
			d := time.Duration(s)*time.Second + time.Duration(ns)*time.Nanosecond
			x := fmt.Sprintf("%.9f", d.Seconds())
			x = strings.TrimSuffix(x, "000")
			x = strings.TrimSuffix(x, "000")
			out.write(`"`)
			out.write(x)
			out.write(`s"`)
			return out.err
		case "Struct":
			return m.marshalValue(out, &proto.Properties{}, s.Field(0), indent)
		case "Timestamp":
			s, ns := s.Field(0).Int(), s.Field(1).Int()
			t := time.Unix(s, ns).UTC()
			x := t.Format("2006-01-02T15:04:05.000000000")
			x = strings.TrimSuffix(x, "000")
			x = strings.TrimSuffix(x, "000")
			out.write(`"`)
			out.write(x)
			out.write(`Z"`)
			return out.err
		case "Value":
			kind := s.Field(0)
			if kind.IsNil() {
				return errors.New("nil Value")
			}
			x := kind.Elem().Elem().Field(0)
			return m.marshalValue(out, &proto.Properties{}, x, indent)
		}
	}
	out.write("{")
	if m.Indent != "" {
		out.write("\n")
	}
	firstField := true
	if typeURL != "" {
		if err := m.marshalTypeURL(out, indent, typeURL); err != nil {
			return err
		}
		firstField = false
	}
	for i := 0; i < s.NumField(); i++ {
		value := s.Field(i)
		valueField := s.Type().Field(i)
		if strings.HasPrefix(valueField.Name, "XXX_") {
			continue
		}
		switch value.Kind() {
		case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
			if value.IsNil() {
				continue
			}
		}
		if !m.EmitDefaults {
			switch value.Kind() {
			case reflect.Bool:
				if !value.Bool() {
					continue
				}
			case reflect.Int32, reflect.Int64:
				if value.Int() == 0 {
					continue
				}
			case reflect.Uint32, reflect.Uint64:
				if value.Uint() == 0 {
					continue
				}
			case reflect.Float32, reflect.Float64:
				if value.Float() == 0 {
					continue
				}
			case reflect.String:
				if value.Len() == 0 {
					continue
				}
			}
		}
		if valueField.Tag.Get("protobuf_oneof") != "" {
			sv := value.Elem().Elem()  
			value = sv.Field(0)
			valueField = sv.Type().Field(0)
		}
		prop := jsonProperties(valueField, m.OrigName)
		if !firstField {
			m.writeSep(out)
		}
		if err := m.marshalField(out, prop, value, indent); err != nil {
			return err
		}
		firstField = false
	}
	if ep, ok := v.(proto.Message); ok {
		extensions := proto.RegisteredExtensions(v)
		ids := make([]int32, 0, len(extensions))
		for id, desc := range extensions {
			if !proto.HasExtension(ep, desc) {
				continue
			}
			ids = append(ids, id)
		}
		sort.Sort(int32Slice(ids))
		for _, id := range ids {
			desc := extensions[id]
			if desc == nil {
				continue
			}
			ext, extErr := proto.GetExtension(ep, desc)
			if extErr != nil {
				return extErr
			}
			value := reflect.ValueOf(ext)
			var prop proto.Properties
			prop.Parse(desc.Tag)
			prop.JSONName = fmt.Sprintf("[%s]", desc.Name)
			if !firstField {
				m.writeSep(out)
			}
			if err := m.marshalField(out, &prop, value, indent); err != nil {
				return err
			}
			firstField = false
		}
	}
	if m.Indent != "" {
		out.write("\n")
		out.write(indent)
	}
	out.write("}")
	return out.err
}
func (m *Marshaler) writeSep(out *errWriter) {
	if m.Indent != "" {
		out.write(",\n")
	} else {
		out.write(",")
	}
}
func (m *Marshaler) marshalAny(out *errWriter, any proto.Message, indent string) error {
	v := reflect.ValueOf(any).Elem()
	turl := v.Field(0).String()
	val := v.Field(1).Bytes()
	mname := turl
	if slash := strings.LastIndex(mname, "/"); slash >= 0 {
		mname = mname[slash+1:]
	}
	mt := proto.MessageType(mname)
	if mt == nil {
		return fmt.Errorf("unknown message type %q", mname)
	}
	msg := reflect.New(mt.Elem()).Interface().(proto.Message)
	if err := proto.Unmarshal(val, msg); err != nil {
		return err
	}
	if _, ok := msg.(wkt); ok {
		out.write("{")
		if m.Indent != "" {
			out.write("\n")
		}
		if err := m.marshalTypeURL(out, indent, turl); err != nil {
			return err
		}
		m.writeSep(out)
		if m.Indent != "" {
			out.write(indent)
			out.write(m.Indent)
			out.write(`"value": `)
		} else {
			out.write(`"value":`)
		}
		if err := m.marshalObject(out, msg, indent+m.Indent, ""); err != nil {
			return err
		}
		if m.Indent != "" {
			out.write("\n")
			out.write(indent)
		}
		out.write("}")
		return out.err
	}
	return m.marshalObject(out, msg, indent, turl)
}
func (m *Marshaler) marshalTypeURL(out *errWriter, indent, typeURL string) error {
	if m.Indent != "" {
		out.write(indent)
		out.write(m.Indent)
	}
	out.write(`"@type":`)
	if m.Indent != "" {
		out.write(" ")
	}
	b, err := json.Marshal(typeURL)
	if err != nil {
		return err
	}
	out.write(string(b))
	return out.err
}
func (m *Marshaler) marshalField(out *errWriter, prop *proto.Properties, v reflect.Value, indent string) error {
	if m.Indent != "" {
		out.write(indent)
		out.write(m.Indent)
	}
	out.write(`"`)
	out.write(prop.JSONName)
	out.write(`":`)
	if m.Indent != "" {
		out.write(" ")
	}
	if err := m.marshalValue(out, prop, v, indent); err != nil {
		return err
	}
	return nil
}
func (m *Marshaler) marshalValue(out *errWriter, prop *proto.Properties, v reflect.Value, indent string) error {
	var err error
	v = reflect.Indirect(v)
	if v.Kind() == reflect.Slice && v.Type().Elem().Kind() != reflect.Uint8 {
		out.write("[")
		comma := ""
		for i := 0; i < v.Len(); i++ {
			sliceVal := v.Index(i)
			out.write(comma)
			if m.Indent != "" {
				out.write("\n")
				out.write(indent)
				out.write(m.Indent)
				out.write(m.Indent)
			}
			if err := m.marshalValue(out, prop, sliceVal, indent+m.Indent); err != nil {
				return err
			}
			comma = ","
		}
		if m.Indent != "" {
			out.write("\n")
			out.write(indent)
			out.write(m.Indent)
		}
		out.write("]")
		return out.err
	}
	type wkt interface {
		XXX_WellKnownType() string
	}
	if wkt, ok := v.Interface().(wkt); ok {
		switch wkt.XXX_WellKnownType() {
		case "NullValue":
			out.write("null")
			return out.err
		}
	}
	if !m.EnumsAsInts && prop.Enum != "" {
		enumStr := v.Interface().(fmt.Stringer).String()
		var valStr string
		if v.Kind() == reflect.Ptr {
			valStr = strconv.Itoa(int(v.Elem().Int()))
		} else {
			valStr = strconv.Itoa(int(v.Int()))
		}
		isKnownEnum := enumStr != valStr
		if isKnownEnum {
			out.write(`"`)
		}
		out.write(enumStr)
		if isKnownEnum {
			out.write(`"`)
		}
		return out.err
	}
	if v.Kind() == reflect.Struct {
		return m.marshalObject(out, v.Addr().Interface().(proto.Message), indent+m.Indent, "")
	}
	if v.Kind() == reflect.Map {
		out.write(`{`)
		keys := v.MapKeys()
		sort.Sort(mapKeys(keys))
		for i, k := range keys {
			if i > 0 {
				out.write(`,`)
			}
			if m.Indent != "" {
				out.write("\n")
				out.write(indent)
				out.write(m.Indent)
				out.write(m.Indent)
			}
			b, err := json.Marshal(k.Interface())
			if err != nil {
				return err
			}
			s := string(b)
			if !strings.HasPrefix(s, `"`) {
				b, err := json.Marshal(s)
				if err != nil {
					return err
				}
				s = string(b)
			}
			out.write(s)
			out.write(`:`)
			if m.Indent != "" {
				out.write(` `)
			}
			if err := m.marshalValue(out, prop, v.MapIndex(k), indent+m.Indent); err != nil {
				return err
			}
		}
		if m.Indent != "" {
			out.write("\n")
			out.write(indent)
			out.write(m.Indent)
		}
		out.write(`}`)
		return out.err
	}
	// Default handling defers to the encoding/json library.
	b, err := json.Marshal(v.Interface())
	if err != nil {
		return err
	}
	needToQuote := string(b[0]) != `"` && (v.Kind() == reflect.Int64 || v.Kind() == reflect.Uint64)
	if needToQuote {
		out.write(`"`)
	}
	out.write(string(b))
	if needToQuote {
		out.write(`"`)
	}
	return out.err
}
type Unmarshaler struct {
	AllowUnknownFields bool
}
func (u *Unmarshaler) UnmarshalNext(dec *json.Decoder, pb proto.Message) error {
	inputValue := json.RawMessage{}
	if err := dec.Decode(&inputValue); err != nil {
		return err
	}
	return u.unmarshalValue(reflect.ValueOf(pb).Elem(), inputValue, nil)
}
func (u *Unmarshaler) Unmarshal(r io.Reader, pb proto.Message) error {
	dec := json.NewDecoder(r)
	return u.UnmarshalNext(dec, pb)
}
func UnmarshalNext(dec *json.Decoder, pb proto.Message) error {
	return new(Unmarshaler).UnmarshalNext(dec, pb)
}
func Unmarshal(r io.Reader, pb proto.Message) error {
	return new(Unmarshaler).Unmarshal(r, pb)
}
func UnmarshalString(str string, pb proto.Message) error {
	return new(Unmarshaler).Unmarshal(strings.NewReader(str), pb)
}