package codecutil

import (
	"io"
	"time"
)

// LexBytes reads n bytes from src and writes them to dst every t seconds.
func LexBytes(dst io.Writer, src io.Reader, t time.Duration, n int) error {
	var tick <-chan time.Time
	if t == 0 {
		tick = make(chan time.Time)
	} else {
		ticker := time.NewTicker(t)
		defer ticker.Stop()
		tick = ticker.C
	}

	for {
		<-tick
		buf := make([]byte, n)
		_, err := src.Read(buf)
		if err != nil {
			return err
		}
		_, err = dst.Write(buf)
		if err != nil {
			return err
		}
	}
}