package object

import (
	"errors"

	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/object"
	refs "git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/refs"
	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
)

// ECHeader represents erasure coding header.
type ECHeader struct {
	parent       oid.ID
	index        uint32
	total        uint32
	header       []byte
	headerLength uint32
}

// NewECHeader constructs new erasure coding header.
func NewECHeader(parent oid.ID, index, total uint32, header []byte, headerLength uint32) *ECHeader {
	return &ECHeader{
		parent:       parent,
		index:        index,
		total:        total,
		header:       header,
		headerLength: headerLength,
	}
}

// WriteToV2 converts SDK structure to v2-api one.
func (e *ECHeader) WriteToV2(h *object.ECHeader) {
	var parent refs.ObjectID
	e.parent.WriteToV2(&parent)
	h.Parent = &parent
	h.Index = e.index
	h.Total = e.total
	h.Header = e.header
	h.HeaderLength = e.headerLength
}

// ReadFromV2 converts v2-api structure to SDK one.
func (e *ECHeader) ReadFromV2(h *object.ECHeader) error {
	if h == nil {
		return nil
	}
	if h.Parent == nil {
		return errors.New("empty parent")
	}

	_ = e.parent.ReadFromV2(*h.Parent)
	e.index = h.Index
	e.total = h.Total
	e.header = h.Header
	e.headerLength = h.HeaderLength
	return nil
}

func (o *Object) ECHeader() *ECHeader {
	ec := (*object.Object)(o).GetHeader().GetEC()
	if ec == nil {
		return nil
	}

	h := new(ECHeader)
	_ = h.ReadFromV2(ec)
	return h
}

func (o *Object) SetECHeader(ec *ECHeader) {
	o.setHeaderField(func(h *object.Header) {
		if ec == nil {
			h.SetEC(nil)
			return
		}

		v2 := new(object.ECHeader)
		ec.WriteToV2(v2)
		h.SetEC(v2)
	})
}

func (e *ECHeader) Parent() oid.ID {
	return e.parent
}

func (e *ECHeader) SetParent(id oid.ID) {
	e.parent = id
}

func (e *ECHeader) Index() uint32 {
	return e.index
}

func (e *ECHeader) SetIndex(i uint32) {
	e.index = i
}

func (e *ECHeader) Total() uint32 {
	return e.total
}

func (e *ECHeader) SetTotal(i uint32) {
	e.total = i
}

func (e *ECHeader) Header() []byte {
	return e.header
}

func (e *ECHeader) SetHeader(header []byte) {
	e.header = header
}

func (e *ECHeader) HeaderLength() uint32 {
	return e.headerLength
}

func (e *ECHeader) SetHeaderLength(l uint32) {
	e.headerLength = l
}