websocket.go

// Copyright (c) 2016 Betalo AB
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

package main

import (
	"net"
	"net/http"
	"net/url"
	"time"

	"context"

	"github.com/gorilla/websocket"
)

type websocketResource struct {
	url.URL
}

func (r *websocketResource) Await(ctx context.Context) error {
	netDialer := &net.Dialer{}
	dial := func(network, address string) (net.Conn, error) {
		return netDialer.DialContext(ctx, network, address)
	}
	var timeout time.Duration
	if deadline, ok := ctx.Deadline(); ok {
		timeout = deadline.Sub(time.Now())
	}
	wsDialer := &websocket.Dialer{
		NetDial:          dial,
		HandshakeTimeout: timeout,
		Proxy:            http.ProxyFromEnvironment,
	}

	// IDEA(uwe): Use fragment to specify origin
	// IDEA(uwe): Use fragment to specify subprotocol
	// IDEA(uwe): Use fragment to specify cookies

	conn, _, err := wsDialer.Dial(r.URL.String(), nil)
	if err != nil {
		return &unavailableError{err}
	}
	defer conn.Close()

	return nil
}