package statusline

import (
	"fmt"
	"io"
)

type StatusLine interface {
	Put(line string)
	End(keep bool)
}

type statusLine struct {
	out     io.Writer
	prevLen int
}

func New(out io.Writer) StatusLine {
	return &statusLine{out: out}
}

func (sl *statusLine) Put(line string) {
	fmt.Fprintf(sl.out, "\r%-[1]*[2]s", sl.prevLen, line)
	sl.prevLen = len(line)
}

func (sl *statusLine) End(keep bool) {
	if keep {
		io.WriteString(sl.out, "\n")
	} else {
		fmt.Fprintf(sl.out, "\r%-[1]*[2]s\r", sl.prevLen, "")
	}
}