// Copyright 2014 The Go Authors. All rights reserved.

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

package internal

import (

	"net/http"

)

// HTTPClient is the context key to use with golang.org/x/net/context's

// WithValue function to associate an *http.Client value with a context.

var HTTPClient ContextKey

// ContextKey is just an empty struct. It exists so HTTPClient can be

// an immutable public variable with a unique type. It's immutable

// because nobody else can create a ContextKey, being unexported.

type ContextKey struct{}

var appengineClientHook func(context.Context) *http.Client

func ContextClient(ctx context.Context) *http.Client {

	if ctx != nil {

		if hc, ok := ctx.Value(HTTPClient).(*http.Client); ok {

			return hc

		}

	}

	if appengineClientHook != nil {

		return appengineClientHook(ctx)

	}

	return http.DefaultClient

}