package object

import (
	objectgrpc "git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/object/grpc"
	"github.com/golang/protobuf/proto"
	"google.golang.org/protobuf/encoding/protojson"
)

// Attribute represents v2-compatible object attribute.
type Attribute struct {
	attribute *objectgrpc.Header_Attribute
}

// NewAttributeFromV2 wraps v2 Attribute message to Attribute.
//
// Nil objectgrpc.Header_Attribute converts to nil.
func NewAttributeFromV2(a *objectgrpc.Header_Attribute) *Attribute {
	if a == nil {
		return nil
	}
	attr := Attribute{
		attribute: &objectgrpc.Header_Attribute{},
	}
	proto.Merge(attr.attribute, a)
	return &attr
}

// NewAttribute creates and initializes blank Attribute.
//
// Works similar as NewAttributeFromV2(new(Attribute)).
//
// Defaults:
//   - key: "";
//   - value: "".
func NewAttribute() *Attribute {
	return NewAttributeFromV2(new(objectgrpc.Header_Attribute))
}

// Key returns key to the object attribute.
func (a *Attribute) GetKey() string {
	return a.attribute.GetKey()
}

// SetKey sets key to the object attribute.
func (a *Attribute) SetKey(v string) {
	a.attribute.SetKey(v)
}

// Value return value of the object attribute.
func (a *Attribute) GetValue() string {
	return a.attribute.GetValue()
}

// SetValue sets value of the object attribute.
func (a *Attribute) SetValue(v string) {
	a.attribute.SetValue(v)
}

// ToV2 converts Attribute to v2 Attribute message.
//
// Nil Attribute converts to nil.
func (a *Attribute) ToV2() *objectgrpc.Header_Attribute {
	if a == nil {
		return nil
	}
	return a.attribute
}

// Marshal marshals Attribute into a protobuf binary form.
func (a *Attribute) Marshal() ([]byte, error) {
	return a.attribute.StableMarshal(nil), nil
}

// Unmarshal unmarshals protobuf binary representation of Attribute.
func (a *Attribute) Unmarshal(data []byte) error {
	return proto.Unmarshal(data, a.attribute)
}

// MarshalJSON encodes Attribute to protobuf JSON format.
func (a *Attribute) MarshalJSON() ([]byte, error) {
	return protojson.MarshalOptions{
		EmitUnpopulated: true,
	}.Marshal(
		a.attribute,
	)
}

// UnmarshalJSON decodes Attribute from protobuf JSON format.
func (a *Attribute) UnmarshalJSON(data []byte) error {
	return protojson.Unmarshal(data, a.attribute)
}