package pubsub

import (
	"io"

	cskrpubsub "github.com/cskr/pubsub"
)

type PubSubWriter struct {
	*cskrpubsub.PubSub
	topic  string
	closed bool
}

func NewPubSubWriter() *PubSubWriter {
	pipe := new(PubSubWriter)
	pipe.PubSub = cskrpubsub.New(1)
	return pipe
}

func (pipe *PubSubWriter) Write(p []byte) (n int, err error) {
	if pipe.closed {
		err = io.EOF
		return
	}
	pipe.PubSub.Pub(p, "")
	n = len(p)
	return
}

func (pipe *PubSubWriter) Close() (err error) {
	if pipe.closed {
		err = io.EOF
		return
	}
	pipe.PubSub.Shutdown()
	pipe.closed = true
	return
}

func (pipe *PubSubWriter) Sub() io.ReadCloser {
	return &PubSubReader{
		channel: pipe.PubSub.Sub(""),
		pubsub:  pipe.PubSub,
		closed:  pipe.closed,
	}
}