package util

import (
	"io"
	"regexp"
)

// Strip ansi control characters from source
//
// The source reader is automatically closed when stripper reader is
type AnsiStripper struct {
	regex  regexp.Regexp
	source io.ReadCloser
}

func NewAnsiStripper(source io.ReadCloser) *AnsiStripper {
	striper := new(AnsiStripper)
	striper.regex = *regexp.MustCompile(`\x1b[[0-9;]*m`)
	striper.source = source

	return striper
}

func (rc AnsiStripper) Read(p []byte) (int, error) {
	n, err := rc.source.Read(p)
	if err != io.EOF && err != nil {
		return n, err
	}

	stripped := rc.regex.ReplaceAll(p[:n], []byte(""))
	n = copy(p, stripped)

	return n, err
}

func (rc AnsiStripper) Close() error {
	return rc.source.Close()
}