1// Copyright 2018 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package impl
6
7import (
8	"fmt"
9	"reflect"
10
11	pref "google.golang.org/protobuf/reflect/protoreflect"
12)
13
14func newListConverter(t reflect.Type, fd pref.FieldDescriptor) Converter {
15	switch {
16	case t.Kind() == reflect.Ptr && t.Elem().Kind() == reflect.Slice:
17		return &listPtrConverter{t, newSingularConverter(t.Elem().Elem(), fd)}
18	case t.Kind() == reflect.Slice:
19		return &listConverter{t, newSingularConverter(t.Elem(), fd)}
20	}
21	panic(fmt.Sprintf("invalid Go type %v for field %v", t, fd.FullName()))
22}
23
24type listConverter struct {
25	goType reflect.Type // []T
26	c      Converter
27}
28
29func (c *listConverter) PBValueOf(v reflect.Value) pref.Value {
30	if v.Type() != c.goType {
31		panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), c.goType))
32	}
33	pv := reflect.New(c.goType)
34	pv.Elem().Set(v)
35	return pref.ValueOfList(&listReflect{pv, c.c})
36}
37
38func (c *listConverter) GoValueOf(v pref.Value) reflect.Value {
39	rv := v.List().(*listReflect).v
40	if rv.IsNil() {
41		return reflect.Zero(c.goType)
42	}
43	return rv.Elem()
44}
45
46func (c *listConverter) IsValidPB(v pref.Value) bool {
47	list, ok := v.Interface().(*listReflect)
48	if !ok {
49		return false
50	}
51	return list.v.Type().Elem() == c.goType
52}
53
54func (c *listConverter) IsValidGo(v reflect.Value) bool {
55	return v.IsValid() && v.Type() == c.goType
56}
57
58func (c *listConverter) New() pref.Value {
59	return pref.ValueOfList(&listReflect{reflect.New(c.goType), c.c})
60}
61
62func (c *listConverter) Zero() pref.Value {
63	return pref.ValueOfList(&listReflect{reflect.Zero(reflect.PtrTo(c.goType)), c.c})
64}
65
66type listPtrConverter struct {
67	goType reflect.Type // *[]T
68	c      Converter
69}
70
71func (c *listPtrConverter) PBValueOf(v reflect.Value) pref.Value {
72	if v.Type() != c.goType {
73		panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), c.goType))
74	}
75	return pref.ValueOfList(&listReflect{v, c.c})
76}
77
78func (c *listPtrConverter) GoValueOf(v pref.Value) reflect.Value {
79	return v.List().(*listReflect).v
80}
81
82func (c *listPtrConverter) IsValidPB(v pref.Value) bool {
83	list, ok := v.Interface().(*listReflect)
84	if !ok {
85		return false
86	}
87	return list.v.Type() == c.goType
88}
89
90func (c *listPtrConverter) IsValidGo(v reflect.Value) bool {
91	return v.IsValid() && v.Type() == c.goType
92}
93
94func (c *listPtrConverter) New() pref.Value {
95	return c.PBValueOf(reflect.New(c.goType.Elem()))
96}
97
98func (c *listPtrConverter) Zero() pref.Value {
99	return c.PBValueOf(reflect.Zero(c.goType))
100}
101
102type listReflect struct {
103	v    reflect.Value // *[]T
104	conv Converter
105}
106
107func (ls *listReflect) Len() int {
108	if ls.v.IsNil() {
109		return 0
110	}
111	return ls.v.Elem().Len()
112}
113func (ls *listReflect) Get(i int) pref.Value {
114	return ls.conv.PBValueOf(ls.v.Elem().Index(i))
115}
116func (ls *listReflect) Set(i int, v pref.Value) {
117	ls.v.Elem().Index(i).Set(ls.conv.GoValueOf(v))
118}
119func (ls *listReflect) Append(v pref.Value) {
120	ls.v.Elem().Set(reflect.Append(ls.v.Elem(), ls.conv.GoValueOf(v)))
121}
122func (ls *listReflect) AppendMutable() pref.Value {
123	if _, ok := ls.conv.(*messageConverter); !ok {
124		panic("invalid AppendMutable on list with non-message type")
125	}
126	v := ls.NewElement()
127	ls.Append(v)
128	return v
129}
130func (ls *listReflect) Truncate(i int) {
131	ls.v.Elem().Set(ls.v.Elem().Slice(0, i))
132}
133func (ls *listReflect) NewElement() pref.Value {
134	return ls.conv.New()
135}
136func (ls *listReflect) IsValid() bool {
137	return !ls.v.IsNil()
138}
139func (ls *listReflect) protoUnwrap() interface{} {
140	return ls.v.Interface()
141}
142