// Copyright (C) 2019-2022  Nicola Murino
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, version 3.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package sftpd

import (
	"io"
	"os"
)

type listerAt []os.FileInfo

// ListAt returns the number of entries copied and an io.EOF error if we made it to the end of the file list.
// Take a look at the pkg/sftp godoc for more information about how this function should work.
func (l listerAt) ListAt(f []os.FileInfo, offset int64) (int, error) {
	if offset >= int64(len(l)) {
		return 0, io.EOF
	}

	n := copy(f, l[offset:])
	if n < len(f) {
		return n, io.EOF
	}
	return n, nil
}