//go:build linux || freebsd
// +build linux freebsd

package compression

import (
	"compress/lzw"
	"io"
)

const lzwLitWidth = 8

type lzwDecompressor struct {
	*BaseDecompressor
	order lzw.Order
}

func NewLzwDecompressor() *lzwDecompressor { return NewLzwDecompressorWithOrder(lzw.LSB) }

func NewLzwDecompressorWithOrder(order lzw.Order) *lzwDecompressor {
	name := "lzw"
	if order == lzw.MSB {
		name = "lzw-msb"
	}
	return &lzwDecompressor{NewBaseDecompressor(name, []string{}, []string{".z", ".lzw"}), order}
}

func (l *lzwDecompressor) Reader(r io.Reader) (io.ReadCloser, error) {
	return lzw.NewReader(r, l.order, lzwLitWidth), nil
}

type lzwCompressor struct {
	name  string
	order lzw.Order
}

func NewLzwCompressor() *lzwCompressor { return NewLzwCompressorWithOrder(lzw.LSB) }
func NewLzwCompressorWithOrder(order lzw.Order) *lzwCompressor {
	name := "lzw"
	if order == lzw.MSB {
		name = "lzw-msb"
	}
	return &lzwCompressor{name: name, order: order}
}

func (l *lzwCompressor) Name() string { return l.name }

func (l *lzwCompressor) Writer(w io.Writer) (io.WriteCloser, error) {
	return lzw.NewWriter(w, l.order, lzwLitWidth), nil
}

func init() { Register(NewLzwDecompressor()) }