// +build go1.8

// Copyright 2018 Gin Core Team.  All rights reserved.
// Use of this source code is governed by a MIT style
// license that can be found in the LICENSE file.

package gin

import "net/http"

// ResponseWriter ...
type ResponseWriter interface {
	http.ResponseWriter
	http.Hijacker
	http.Flusher
	http.CloseNotifier

	// Returns the HTTP response status code of the current request.
	Status() int

	// Returns the number of bytes already written into the response http body.
	// See Written()
	Size() int

	// Writes the string into the response body.
	WriteString(string) (int, error)

	// Returns true if the response body was already written.
	Written() bool

	// Forces to write the http header (status code + headers).
	WriteHeaderNow()

	// get the http.Pusher for server push
	Pusher() http.Pusher
}

func (w *responseWriter) Pusher() (pusher http.Pusher) {
	if pusher, ok := w.ResponseWriter.(http.ResponseWriter).(http.Pusher); ok {
		return pusher
	}
	return nil
}