// Copyright 2019 The Go Authors. All rights reserved.

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

package impl

import (

	"fmt"

	pref "google.golang.org/protobuf/reflect/protoreflect"

	"google.golang.org/protobuf/reflect/protoregistry"

)

// weakFields adds methods to the exported WeakFields type for internal use.

//

// The exported type is an alias to an unnamed type, so methods can't be

// defined directly on it.

type weakFields WeakFields

func (w weakFields) get(num pref.FieldNumber) (pref.ProtoMessage, bool) {

	m, ok := w[int32(num)]

	return m, ok

}

func (w *weakFields) set(num pref.FieldNumber, m pref.ProtoMessage) {

	if *w == nil {

		*w = make(weakFields)

	}

	(*w)[int32(num)] = m

}

func (w *weakFields) clear(num pref.FieldNumber) {

	delete(*w, int32(num))

}

func (Export) HasWeak(w WeakFields, num pref.FieldNumber) bool {

	_, ok := w[int32(num)]

	return ok

}

func (Export) ClearWeak(w *WeakFields, num pref.FieldNumber) {

	delete(*w, int32(num))

}

func (Export) GetWeak(w WeakFields, num pref.FieldNumber, name pref.FullName) pref.ProtoMessage {

	if m, ok := w[int32(num)]; ok {

		return m

	}

	mt, _ := protoregistry.GlobalTypes.FindMessageByName(name)

	if mt == nil {

		panic(fmt.Sprintf("message %v for weak field is not linked in", name))

	}

	return mt.Zero().Interface()

}

func (Export) SetWeak(w *WeakFields, num pref.FieldNumber, name pref.FullName, m pref.ProtoMessage) {

	if m != nil {

		mt, _ := protoregistry.GlobalTypes.FindMessageByName(name)

		if mt == nil {

			panic(fmt.Sprintf("message %v for weak field is not linked in", name))

		}

		if mt != m.ProtoReflect().Type() {

			panic(fmt.Sprintf("invalid message type for weak field: got %T, want %T", m, mt.Zero().Interface()))

		}

	}

	if m == nil || !m.ProtoReflect().IsValid() {

		delete(*w, int32(num))

		return

	}

	if *w == nil {

		*w = make(weakFields)

	}

	(*w)[int32(num)] = m

}