package minify // import "github.com/tdewolff/minify"

import (

"bytes"

"io"

"unicode"

"github.com/tdewolff/parse"

)

const bufSize = 1024

// Default is a default minifier used to minify an unknown media type.

// It remove all whitespace at the beginning and end of the strea.

func (m Minifier) Default(w io.Writer, r io.Reader) error {

if fr, ok := r.(interface {

Bytes() []byte

}); ok {

b := bytes.TrimSpace(fr.Bytes())

if _, errWrite := w.Write(b); errWrite != nil {

return errWrite

}

return nil

}

head := true

sb := parse.NewShiftBuffer(r)

for {

// cause a read

if sb.Peek(0) == 0 && sb.Err() != nil {

if sb.Err() == io.EOF {

return nil

}

return sb.Err()

}

// consume whole buffer and unconsume trailing whitespace

sb.MoveTo(sb.Len())

trailingLen := sb.Len() - len(bytes.TrimRightFunc(sb.Buffered(), unicode.IsSpace))

sb.Move(-trailingLen)

b := sb.Shift()

if head {

b = bytes.TrimLeftFunc(b, unicode.IsSpace)

head = len(b) == 0 // if it's all whitespace, we still need to trim leading whitespace next time

}

if _, errWrite := w.Write(b); errWrite != nil {

return errWrite

}

sb.Move(trailingLen)

}

}