// Copyright (C) 2022  Luke Shumaker <lukeshu@lukeshu.com>
//
// SPDX-License-Identifier: GPL-2.0-or-later

package btrfsitem

import (
	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct"
)

// Metadata is like Extent, but doesn't have .Info.
type Metadata struct { // METADATA_ITEM=169
	Head ExtentHeader
	Refs []ExtentInlineRef
}

func (o *Metadata) UnmarshalBinary(dat []byte) (int, error) {
	n, err := binstruct.Unmarshal(dat, &o.Head)
	if err != nil {
		return n, err
	}
	o.Refs = nil
	for n < len(dat) {
		var ref ExtentInlineRef
		_n, err := binstruct.Unmarshal(dat[n:], &ref)
		n += _n
		o.Refs = append(o.Refs, ref)
		if err != nil {
			return n, err
		}
	}
	return n, nil
}

func (o Metadata) MarshalBinary() ([]byte, error) {
	dat, err := binstruct.Marshal(o.Head)
	if err != nil {
		return dat, err
	}
	for _, ref := range o.Refs {
		bs, err := binstruct.Marshal(ref)
		dat = append(dat, bs...)
		if err != nil {
			return dat, err
		}
	}
	return dat, nil
}